Introduction

Oncology Letters

1792-1074 1792-1082

D.A. Spandidos

10.3892/ol.2020.12124

OL-0-0-12124

Articles

Steroid 5 alpha-reductase 2 enzyme variants, biomass exposure and tobacco use in Mexican patients with prostate cancer

Delgado-Balderas

Jesus Rolando

1 * Gallardo-Blanco

Hugo Leonid

2 * Yee-De León

Juan Felipe

3 * Rivas-Estilla

Ana Maria

1 Soto-García

Brenda

3 Aráiz-Hernández

Diana

3 Garza-Guajardo

Raquel

4 Náñez-Marín

Melissa

4 Hernández-Barajas

David

5 García-Bailón

Aldo Missael

6 Vízcarra-Mata

Guillermo

6 Ocaña-Munguía

Marco Alberto

6 Gómez-Guerra

Lauro Salvador

6 Sánchez-Domínguez

Celia Nohemí

1Department of Biochemistry and Molecular Medicine, School of Medicine, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico 2Department of Genetics, School of Medicine, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico 3Delee Corp., Mountain View, CA 94041, USA 4Pathological Anatomy and Cytopathology Service, ‘Dr. José Eleuterio González’ University Hospital, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico 5Oncology Service, University Center Against Cancer, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico 6Urology Service, ‘Dr. José Eleuterio González’ University Hospital, Universidad Autónoma de Nuevo León, Monterrey 64460, Mexico

Correspondence to: Dr Lauro Salvador Gómez-Guerra, Urology Service, ‘Dr. José Eleuterio González’ University Hospital, Universidad Autónoma de Nuevo León, Francisco I. Madero Avenue and Dr. José Eleuterio González Avenue, Monterrey 64460, Mexico, E-mail: laurogomez@hotmail.com Dr Celia Nohemí Sánchez-Domínguez, Department of Biochemistry and Molecular Medicine, School of Medicine, Universidad Autónoma de Nuevo León, Francisco I. Madero Avenue and Dr. Eduardo Aguirre Pequeño Street, Monterrey 64460, Mexico, E-mail: celia.sanchezdm@uanl.edu.mx *

Contributed equally

11 2020

18 09 2020

20 5

261

03042020 31072020

2020

This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

The presence of the genetic variants of the steroid 5-alpha reductase 2 enzyme, which is encoded by the SRD5A2 gene, has been associated with an increased risk of developing prostate cancer among certain ethnic groups. However, these molecular studies have not been conducted on the Mexican population. The analysis of the genetic variants, rs9282858 and rs523349, was performed in 101 males with prostate cancer and 100 healthy controls classified as males without prostate abnormalities (n=60) and males with benign prostatic hyperplasia (n=40), to identify a probable association with this cancer type in the Northeast Mexican population. An association was identified between prostate cancer and biomass exposure [P=0.012; odds ratio (OR), 2.89; confidence interval (CI)=1.21–6.88] and tobacco use (P=0.028; OR=1.88; CI=1.07–3.31), while no association was observed between cancer development and the rs9282858 variant, or between a protective effect and the rs523349 variant. Notably, an association was identified between rs523349 and biomass exposure (P=0.013, OR=3.17; CI=1.23–8.17 for the G risk allele, and OR=0.32, CI=0.12–0.81 for the C protective allele) using the dominant genetic model. To the best of our knowledge, the present study was the first of its type to investigate the Mexican population with prostate cancer.

prostate cancer steroid 5 alpha-reductase 2 enzyme A49T (rs9282858) V89L (rs523349) biomass exposure

Introduction

Prostate cancer (PCa) is the second most common type of malignancy among males worldwide; in 2018, the World Health Organization estimated more than 1.3 million new prostate cancer cases and over 359,000 mortalities due to this disease (1). In Mexico, PCa is the most common and fatal cancer type among males, accounting for >10,000 new cases and 5,000 mortalities during the same period of time (1). PCa is usually diagnosed in the fifth decade of life, with a variable rate of progression that largely depends on genetic and environmental factors, as well as the patient's lifestyle (2).

Androgens are necessary for the correct development and function of the prostate gland; however, they also serve a critical role in driving the growth of early-stage PCa (3). Androgen action, mediated by the androgen receptor (AR), leads to the activation of target genes that stimulate the proliferation and inhibit the apoptosis of cancer cells (3,4). Free testosterone diffuses across the membranes of target cells located within the prostatic tissue acting as a substrate for the steroid 5 alpha-reductase 2 enzyme (encoded by the SRD5A2 gene), which converts testosterone to dihydrotestosterone (DHT), a more potent metabolite that activates the AR (5). Once activated, the AR is translocated to the nucleus where it dimerizes with another AR and activates target genes that promote cell proliferation (3,4,6,7) (Fig. 1).

Certain DNA variants in the genomic sequence of the SRD5A2 gene alter the catalytic activity of steroid 5-alpha reductase 2, which may increase the risk of PCa development (8–11). In this context, certain variants have been associated with an increased risk of developing PCa, including TA dinucleotides in the 3′-UTR region (12,13), rs9332964 (14,15), rs928258 (9) and rs523349 (16,17). The rs928258 and rs523349 variants have been screened mainly across different ethnic groups.

The rs9282858 (p.Ala49Thr or A49T) variant results from a single nucleotide substitution, a G by an A (GCC/ACC), causing an amino acid change from an alanine to a threonine. It has been reported that this change increases the catalytic activity of the enzyme by 5-fold (14,18). The ENSEMBL database reports this variant as a) benign in ClinVar, b) deleterious in SIFT, c) benign in PolyPhen, and d) likely benign in CADD (http://www.ensembl.org/Homo_sapiens/Variation/Mappings?db=core;r=2:31580256-31581256;v=rs9282858;vdb=variation;vf=57248637).

By contrast, the rs523349 (p.Val89Leu or V89L) variant results from a single nucleotide substitution, a C by a G (CTA/GTA), causing an amino acid change from a valine to a leucine. It has been reported that this change reduces the enzyme activity by 30% (14,16,19). The ENSEMBL database reports this variant as a) benign in ClinVar, b) tolerated substitution in SIFT, c) benign in PolyPhen, and d) likely benign in CADD (http://www.ensembl.org/Homo_sapiens/Variation/Mappings?db=core;r=2:31580136-31581136;v=rs523349;vdb=variation;vf=54157055).

As in a number of other diseases, the molecular findings on populations of European descent cannot be assumed for all populations. To implement a precision medicine model, molecular studies must be performed in diverse ethnic groups of interest. Genomic and genetic data of populations of non-European descendants remain under represented (20).

The Mexican population is genetically diverse (21); therefore, a more detailed study of the population structure alongside geographical data is required to assess the frequency and prevalence of genetic diseases in native and Mexican-mestizo populations (21–23). In diseases, including prostate cancer, this information may aid in diagnosis, prognosis, and treatment (21,22).

In Mexico, PCa is a national health problem, but molecular studies regarding PCa in this population are limited. Certain studies with regard to AR, VDR (24), VEGF (25), ATP6, and ND3 (26) genetic variants have been made. However, to the best of our knowledge, there are no previous reports that analyze the presence of the genetic variants, A49T and V89L, of the steroid 5 alpha-reductase 2 enzyme in the Mexican-mestizo population. Therefore, a molecular analysis of these genetic variants and examination of relevant clinical data was performed in the present study to identify a possible association with the development of PCa on the Mexican-mestizo population.

Materials and methods <sec> <title>Study design

The protocol was approved by the Ethics and Research Committee of the School of Medicine of the Universidad Autónoma de Nuevo León (no. UR16-00007). This protocol was performed by the Biochemistry and Molecular Medicine Department using convenience sampling. Participants were enrolled between January 2018 and December 2019 through the Urology and Oncology Services from the ‘Dr. José Eleuterio González’ University Hospital of the Universidad Autónoma de Nuevo León, and each patient provided written informed consent to participate in the present study.

Recruited participants were classified into three groups according to subsequent analyses: PCa cases (n=101; median age, 70 years; age range, 64.5–75.0 years) and non-PCa subjects (n=100; median age, 58 years; age range, 48–67 years) composed of males without prostate abnormalities (n=60) and subjects with benign prostatic hyperplasia (BPH; n=40). The PCa cases were males diagnosed with PCa regardless of the time elapsed since the diagnosis or their treatment status.

Blood samples were collected in a 6 ml BD Vacutainer tube with EDTA (Becton-Dickinson). Demographic data of clinical importance were collected, and the database was prepared. PSA levels were analyzed only for the PCa and BPH groups.

DNA extraction protocol

Each blood sample was centrifuged at 3,857 g for 10 min at room temperature. From the buffy coat, DNA extraction was performed using a previously reported method with TSNT lysis buffer (composed of 1% Triton, 1% sodium dodecyl sulfate, 100 mM NaCl, 10 mM Tris-HCl pH 8.0 and 1 mM EDTA) and followed by a phenol-chloroform extraction step (27,28). The DNA was precipitated from aqueous phase with ethanol and quantified using NanoDrop 1000 (Thermo Fisher Scientific, Inc.) and its quality was verified through absorbance ratios (260/280 and 260/230 nm) and agarose gel electrophoresis.

Genotyping

Genotyping assays were performed using the commercial TaqMan SNP Genotyping Assays probes C__27532228_20 and C___2362601_10 (Thermo Fisher Scientific, Inc.) for the A49T (rs9282858) and V89L (rs523349) gene variants of the SRD5A2 gene (NM_000348.3), respectively.

DNA samples were processed using a StepOnePlus™ Real-Time PCR system (Thermo Fisher Scientific, Inc.). Each PCR reaction was performed using 5 µl SensiFAST™ Hi-Rox Genotyping kit (Bioline; Meridian Bioscience, Inc.), 0.5 µl probe, 5 µl nuclease-free water, and 3 µl DNA (300 ng).

The amplification program used was the following: Pre-PCR read 60°C/30 sec, holding stage 95°C/10 min, cycling stage: i) 95°C/15 sec; ii) 60°C/1 min, and post-PCR read 60°C/30 sec. The results were analyzed using the StepOne™ software v.2.2.2, (Thermo Fisher Scientific, Inc.).

Statistical analysis

Gene analysis was conducted using the Golden Helix SNP & Variation Suite 8.8.3 program (Golden Helix, Inc.). The DNA variants were analyzed for deviation from the Hardy-Weinberg Equilibrium (HWE) using the Fisher's exact test (P<0.05 was considered to indicate a statistically significant difference and HW disequilibrium). The genetic association study was performed using the dominant and recessive gene models in order to assess odds ratios (ORs), 95% confidence intervals (CIs), Bonferroni P-values and false discovery rates (FDRs) (23). The dominant model considered the analyzed phenotypes of Ala/Ala+Ala/Thr vs. Thr/Thr for the rs9282858 and Val/Val+Val/Leu vs. Leu/Leu for the rs523349 variants. On the other hand, the recessive genetic model considered the analyzed phenotypes Ala/Ala vs. Ala/Thr+Thr/Thr for the rs9282858 and Val/Val vs. Val/Leu+Leu/Leu for the rs523349 variants (29).

For the regression association study, a stepwise linear regression model (qthelp://org.sphinx.svsmanual.8.8.3/doc/svsmanual/ftParts/logistic_regression.html) with recoded genotypes with the additive gene model (DD=2, Dd=1, dd=0) was used. False discovery rate correction (FDR) was calculated to exclude spurious associations (qthelp://org.sphinx.svsmanual.8.8.3/doc/svsmanual/ftParts/general_statistics.html).

Results <sec> <title>Clinical characteristics of cases and controls enrolled in the present study

The present study included 201 participants classified as patients with PCa (n=101) and non-PCa subjects, including males without prostate abnormalities (n=60) and subjects with BPH (n=40). For patients with PCa, the median age (IQR) was 70 (range, 64.5–75) years. Thirty percent of patients had a history of prostate pathology, while the median prostate-specific antigen (PSA) value was 20.4 (IQR, 9.65–62.82); 20.8% had type 2 diabetes mellitus (T2DM), and body mass index (BMI) calculations for this group found that 33.7% were a normal weight, 40.8% were overweight, and 22.4% had some degree of obesity. Gleason Grading was calculated according to the recommendations of the International Society of Urological Pathology (ISUP) (30). A total of 62% of patients were classified as Gleason Grade Group 5, as they had tumors with Gleason scores of 9 and 10. The majority of patients (67%) received androgen deprivation therapy (ADT), predominantly bicalutamide alone or in combination with other drugs, such as goserelin and leuprolide. Table I shows the detailed clinical variables of the patients with PCa.

For the non-PCa subjects, the median age (IQR) was 58.8 (range, 48–67) years; 42.4% had a history of prostate pathology, while the median PSA value for subjects with BPH was 8.55 ng/ml (IQR, 5.12–17.71); 21% had T2DM, and the BMI calculations for this group found that 23.1% were a normal weight, 44.9% were overweight, and the remaining 32.1% had some degree of obesity.

Table II summarizes the relevant data of the patients with PCa and non-PCa subjects enrolled in the present study. Notably, an association was identified between PCa and biomass exposure (P=0.012; OR=2.89; CI=1.21–6.88) and tobacco use (P=0.028; OR=1.88; CI=1.07–3.31), compared with controls.

Genotyping

Table III shows the HWE analysis for PCa cases and controls, as well as the genotype frequencies. The A49T variant was out of HWE equilibrium in the population analyzed, unlike the V89L variant, which was maintained in HWE.

Statistical analysis

The results of the association analysis were categorized according to the method used. In the present study, dominant and recessive gene models were used to perform analysis. No association was identified in any of the conditions of the models or in the development of PCa (A49T variant) or in conferring a protective effect (V89L variant). Table IV presents the results obtained for the variants A49T and V89L after performing a statistical analysis using the dominance and recessiveness gene models, as well as the OR and 95% CI range.

Clinical and genetic features association

The analysis between clinical and genetic features was conducted using V89L genotypes. No association was identified between genotyping and clinical variables, including PSA, ISUP Grade Group, or a history BPH. However, an association was identified between rs523349 and biomass exposure (P=0.013; OR=3.17; CI=1.23–8.17 for the G risk allele, and OR=0.32, CI=0.12–0.81 for the C protective allele) using the dominant gene model (https://doi.org/10.5281/zenodo.3932702). There was an association between V89L and patients with metastasis (Val/Val vs. Leu/Leu+Val/Leu; P=0.048; OR=0.390; CI=0.142–1.073; Table V).

Discussion

Previous studies that have used the Mexican population as a subject of study have reported an association between certain variants in the SDR5A2 gene and diseases, including pseudo hermaphroditism and hypospadias (31–34), but not PCa. The effect of the two analyzed variants is different according to the ethnic group of study. For example, homozygous subjects possessing the V89L variant (Val/Val) may have a protective effect if its origin is from Asia, but subjects with this same phenotype may have an increased risk of developing PCa. Cancer is a complex set of diseases in which different risk factors serve a crucial role in its development, where the genetic background is only one of them.

Logistic regression is an essential tool used in many clinical applications, including in clinical prediction models (35), patient screening (36), and for the developing and validation of novel diagnostic models (37). The clinical importance of genotyping the genetic variants analyzed in the present study lies in predicting the behaviour of the metabolic AR pathway. Logistic regression may then be applied in clinical prediction models, to develop and validate novel diagnostic models, and to assess and predict the success of steroid 5 alpha-reductase 2 inhibitors (38).

In the present study, the participants enrolled were males with diagnosed PCa, males with other urological diseases, or men without any apparent urological condition that serve as healthy controls. PCa is more frequently diagnosed in the fifth decade of life; therefore, the statistical difference between the ages of PCa vs. non-PCa subjects in the present study was expected. The analysis of specific clinical variables revealed that PCa was associated with certain risk factors, including tobacco use and biomass exposure. It was found that the median PSA value derived from the PCa cases (20.4 ng/ml) was significantly higher than that for the non-PCa subjects (8.5 ng/ml) included in the present study (P<0.001), which is consistent with the results of previous studies (39,40). It was reported that 125/973 (12.8%) of participants had PSA values >4 ng/ml and 55 (44%) were diagnosed with PCa in a previous screening study conducted by part of our research group in the Northeast Mexican population (41).

A limitation of our work was the lack of availability of PSA values in healthy controls. This limitation is due to the fact that all participants were recruited as a convenience sample by the Urology Department and that non-PCa cases were men with BPH (n=40) or persons classified as men without prostate abnormalities (n=60). The association of the gene variants analyzed in this work was made by comparing PCa vs. total non-PCa subjects.

No association was identified between T2DM and prostate cancer development. However, the study subjects were only classified as diabetic or not, without accounting for their glucose levels or medications. A recent meta-analysis of 733 articles identifying 17 cohort studies that included 274,677 male patients suggested that diabetes may result in a poorer prognosis for males with PCa, but was not associated with PCa development (42). Another independent study reported an increased risk of mortality with PCa in diabetics, but not an association between diabetes and the incidence of prostate cancer (43). This may be explained by the comorbidities associated with T2DM, including atherosclerosis and renal failure, as patients with T2DM and other comorbidities may have a poorer response to treatment. Two meta-analyses reported a relative low risk of develop PCa in patients with T2DM (44,45). Other studies have presented controversial results regarding this comorbidity (46–48). Previously, our research team identified an increased risk of developing PCa with Gleason Scores >8 in patients with high glucose levels (49).

Additionally, a significant difference (P=0.028) was reported between tobacco use in PCa patients and non-PCa subjects (60.4% vs. 43%, respectively). Several previous studies have reported tobacco use as a risk factor for developing PCa (50–52). Smokers have an increased risk of developing certain types of cancer, including lung cancer. However, it has been recognized that tobacco use may contribute toward the development of urological cancer, including prostate, bladder, ureters and kidney (50–53). This could be because chemical compounds released when tobacco is burned are distributed from the lung blood vessels to other tissues of the body.

When tobacco is burned, it produces carcinogenic compounds, mainly polycyclic aromatic hydrocarbons (PAHs) and nicotine- derived nitrosamines, including N′-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In brief, tumorigenesis is caused by the formation of DNA adducts. These adducts generate mutations in key cell maintenance genes; the NNNs and NNKs may bind to acetylcholine receptors and promote events, including proliferation, growth, survival and cell migration (54). Furthermore, PAHs may bind to aryl hydrocarbon receptors (AHRs), which activate CYP1A1 and CYP1B1; the CYPs add an epoxide group to the PAHs, and these PHAs-epoxide complexes may bind to DNA to form adducts, which are crucial for tumorigenesis (55).

Notably, there was a significant difference between biomass exposure in patients with PCa and that in non-PCa subjects (20.8 vs. 8%; P=0.012; OR=2.89; CI=1.21–6.88). The Mexican population (mainly its Northern population) has a tradition for cooking grilled foods and performing other activities, such as working for petrochemical, steel and construction industries, that generate particles of sizes of <10 µm, or being exposed to xenobiotic compounds, including polycyclic aromatic hydrocarbons (PAHs) (56). In the present study, the participants were surveyed to see with what frequency they cook their foods using wood. A previous study demonstrated how the exposure to this biomass is associated with the development of different types of cancer, primarily lung cancer (57). The mechanism by which the biomass compounds promote cancer development is unclear, but we hypothesize that it is associated with PAHs, primarilybenzo(a)pyrene. Benzo(a)pyrene serves a role in the formation of DNA adducts (58), specifically in the mutations involving the nucleotide change from G to T in the codons 157, 158, 248, and 273 of the TP53 gene, with catastrophic consequences according to the IARC TP53 Database (R20, July 2019) (59). The two risk factors identified in the present study associated with benzo(a)pyrene were tobacco use and biomass exposure. The risk factor that was statistically significant following FDR correction was biomass exposure. Stepwise regression was a useful tool to identify this risk factor.

There are few studies on biomass exposure and PCa development, the most important of which is the Cancer Prevention Studio-II (CPS-II) of the American Cancer Society (60); however, the authors assessed risk factors for lung cancer, so the association with PCa was not investigated.

The A49T variant is associated with an increase in the activity of the5-alpha reductase 2 enzyme, which converts testosterone to dihydrotestosterone (DHT). This more potent metabolite binds to the AR and results in the subsequent activation of target genes that promote cell proliferation, inhibition of apoptotic signals, and PSA overexpression.

A meta-analysis published in 2011 by Li et al (19) reported a significantly higher risk of developing stage III/IV PCa in homozygous variant subjects carrying the A49T variant (Thr/Thr allele), using a recessive gene model (P=0.0001; OR=2.13; CI=1.44–3.15) (19). In the present study, no association was identified between SRD5A2 gene variants and PCa. The results demonstrated that 3% of subjects were carriers of the A49T (Thr/Thr allele) variant and it was not associated with PCa development (P=0.327). A limitation of the results of the present study is the HW disequilibrium, possibly due to the low frequency of this allele or the lack of heterozygous individuals in the sampled population (61,62). Future studies should include an increased number of analyzed samples to verify these results.

Other ethnic groups, Ecuadorian, African American and Latin, had an association with the development of PCa and the A49T variant (Thr/Thr allele) (16,63,64). By contrast, no association between this allele and PCa was identified in analyzes performed on Hispanic and Brazilian populations (65,66). Table VI shows these previously reported genotyping studies and their association with PCa development.

Although patients harboring the A49T variant (Thr/Thr allele) were expected to have high PSA levels, the patients in the present study with the Thr/Thr genotype had PSA values of 5.23, 8.00, and 19.98 ng/ml, possibly due to the tumor stage at the time of diagnosis. A more significant number of patients would be required to verify if there is any correlation between these two variables and PCa development in the Mexican-mestizo population.

As for the V89L variant, the homozygous allele variant Leu/Leu causes a decrease in the catalytic activity of steroid 5 alpha-reductase 2, while the homozygous wild-type Val/Val genotype has been associated with PCa development and higher Gleason stages.

In 1992, Batista et al (5) measured steroid 5-alphareductase 2 activity indirectly by quantifying testosterone metabolites in Afro-American and Asian individuals, finding differences attributed to enzyme activity levels; however, they did not take into account the genotypes of the analyzed subjects (8). This is due to the Leu/Leu allele, and a study in the Asian population reported this result with a protective effect by decreasing the risk of developing PCa (9).

In the present study, patients with this allele may be developing PCa due to other independent metabolic AR pathways, including damage repair DNA genes (67), PTEN (68) or TP53 (69). By contrast, the allele Leu/Leu was associated with cancer development in genotyping studies of European American (70) and Hispanic populations (71). Notably, this allele has been associated with PCa with Gleason scores >8 in the French population (72) and metastasis (73).

The present study identified a decreased statistical trend with regards to metastatic PCa when analyzing carriers of alleles Leu/Leu+Val/Leu vs. Val/Val (P=0.048; OR=0.390; CI=0.142–1.073). To the best of our knowledge, there are no reports that directly determined the cause of this association, but we hypothesized that it may be due to the differential gene expression associated with metastasis in PCa, including EGR2, EGR3, MTA1, MYBL2 (74), SYNPO2, EGR3, RDX, FOXM1 (75), KLF6, MMP9 or WNT5A (76). Additionally, when a naïve PCa is treated with ADT, its evolution to a metastatic state may be due to other transcriptional factors, including GATA2 or FOXA1 (77), fusion mutation TMPRSS2-ERG (78,79) or AR variants (AR-V7) (80,81).

SRD5A2, CYP17A1, and CYP19A1 are involved in the steroid metabolic (GO:0008202) and steroid biosynthetic processes (GO:0006694). In Mus musculus, benzo(a)pyrene has been associated with the Protein-Protein interaction Network oxidation-reduction process (GO:0055114; Permanent link: http://bit.ly/2jIbOER) (82). The genes involved in this network participate in the cytochrome P450-mediated oxidation (Cyp17a1, Cyp19a1, Cyp1a2, Cyp21a1, Cyp3a11, Cyp3a13, Cyp3a16, Cyp3a25 and Cyp3a41a), and the reduction of oestrogens and androgens (Srd5a2, Akr1d1, Hsd17b1 and Hsd3b4).

The Val/Val allele is more common in white Hispanic/non-Hispanic and Ecuadorian populations and it has been associated with PCa development; in the Mexican-mestizo population investigated in the present study, this association was not found. It has been seen that this allele may contribute toward worsening clinical prognosis associated with the overall survival, as was described in a previous study when comparing the different genetic variants and lower AR activity (83).

Table VII summarizes other genotyping studies of V89L and its potential associations with PCa development, metastasis, Gleason score, or protective effects against PCa (9,63,70–73,84).

The analysis performed in the present study demonstrated that there was no association between the SRD5A2 rs523349 genotypes and Gleason scores ≥8; however, there was a decreased tendency between patients with metastasis and rs523349 genotypes (Val/Val vs. Leu/Leu+Val/Leu; P=0.048; OR=0.390; CI=0.142–1.073).

The clinical prognosis of the cohort of patients with PCa included in the present study was associated with 5-alpha reductase 2 variants. However, there are two main limitations: i) The present study included patients with localized and metastatic disease without discriminating the time of evolution, and ii) the type of ADT at the time of enrolment. The first-line treatment of ADT in clinical practice is the administration of bicalutamide, as the public medical care does not include new generation treatments in Mexico, including enzalutamide or abiraterone acetate.

Finally, regarding benign prostate diseases, a meta-analysis undertaken in 2017 by Zeng et al (85) found a risk of developing BPH in individuals carrying the A49T variant (OR=2.75; CI=1.32–5.69), but this was not statistically significance (P=0.373). By contrast, the results of studies concerning the V89L variant and its association with the development of BPH and PSA changes have been contradictory (86,87). A previous study reported that the Val/Leu+Leu/Leu genotype (P=0.047; OR=1.62; CI=1.00–2.61) was associated with the development of this benign condition, but not with the development of PCa (88). However, in another study, none of these genotypes were associated with the development of BPH (85). In the future, a longitudinal analysis of Mexican patients with this type of benign disease should be performed to describe the frequency of the different genetic variants and to determine if they have a role in the prognosis of PCa as potential biomarkers for personalization of pharmacological treatments using 5 alpha-reductase enzyme inhibitors (87).

In conclusion, we identified the allelic frequencies of both the A49T and V89L variants of the steroid 5 alpha-reductase 2 gene in the Mexican population. No association was identified between either of the variants and the development of PCa, but no increased risk of developing PCa was identified due to lifestyle factors, including the exposure to biomass and tobacco use. Furthermore, an association between V89L and biomass exposure was identified using the dominant gene model. Additionally, there was an association between V89L and patients with metastasis.

To the best of our knowledge, the present study was the first to screen the Mexican population for these variants, and one of the focussing on the Latino population. For these ethnic groups, molecular characterization of PCa is required to improve the understanding of this disease, and to determine if the results of molecular characterization studies may serve a role in the prognosis of PCa or as potential biomarkers for the personalization of pharmacological treatments.

Acknowledgements

The authors would like to thank the Dr María Carmen Barboza-Cerda (Laboratorio Nacional Biobanco, LANBIOBAN, Universidad Autónoma de Nuevo León, Monterrey, Mexico), for providing the equipment and facilities to perform certain experiments. They would also like to acknowledge Mr. Eduardo Coronado (Urology Service, ‘Dr. José Eleuterio González’ University Hospital, Universidad Autónoma de Nuevo León, Monterrey, Mexico) for his support in collecting the blood samples for the present study, and Dr. Sergio Lozano-Rodriguez (Office of the Vice Dean of Research, ‘Dr. José Eleuterio González’ University Hospital, Universidad Autónoma de Nuevo León, Monterrey, Mexico) for his review of the English language of this manuscript.

Funding

The present study was supported by the Program for Scientific and Technological Research 2019 of the Universidad Autónoma de Nuevo León, Mexico (PAICyT: SA763-19).

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Authors' contributions

JRDB conducted the experiments, acquired, analyzed and interpreted the data; and drafted the manuscript. JRDB, HLGB, JFYL, LSGG and CNSD designed the study, conducted the experiments, analyzed, interpreted the data, and critically revised the manuscript. CNSD and AMRE made substantial contributions to the conception of the study, and drafted, and critically revised the manuscript. DHB, AMGB, GVM, MAOM and LSGG, as clinicians, selected the patients, performed the biopsies to obtain the samples, collected the clinical information from medical records, and contributed toward the design of the study. DAH and BSG assisted in technical support during the experimental work and were involved in the acquisition, analysis and interpretation of data. RGG and MNM, as pathologists, conducted the histopathological diagnoses of the patients. All authors read and approved the final manuscript.

Ethics approval and consent to participate

The protocol was approved by the Ethics and Research Committee of the School of Medicine (Universidad Autónoma de Nuevo León, Mexico; UR16-00007). Prior to blood extraction, written informed consent was obtained from the eligible participants.

Patient consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Abbreviations

SRD5A2 gene

steroid 5 alpha-reductase 2 gene

A49T

Alanine49Threonine

V89L

Valine89Leucine

adenine

guanine

cytosine

PCR

polymerase chain reaction

Ala

alanine

Thr

threonine

Val

valine

Leu

leucine

Odds ratio

EDTA

ethylenediaminetetraacetic acid

IQR

interquartile range

References 1

Bray

Ferlay

Soerjomataram

Siegel

Torre

Jemal

Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries

CA Cancer J Clin683944242018

10.3322/caac.21492

30207593

Giovannucci

Liu

Platz

Stampfer

Willett

Risk factors for prostate cancer incidence and progression in the health professionals follow-up study

Int J Cancer121157115782007

10.1002/ijc.22788

17450530

Feldman

The development of androgen-independent prostate cancer

Nat Rev Cancer134452001

10.1038/35094009

11900250

Chandrasekar

Yang

Gao

Evans

Mechanisms of resistance in castration-resistant prostate cancer (CRPC)

Transl Androl Urol43653802015

26814148

Batista

Mendonca

Integrative and analytical review of the 5-alpha-reductase type 2 deficiency worldwide

Appl Clin Genet1383962020

10.2147/TACG.S198178

32346305

Kokal

Mirzakhani

Pungsrinont

Baniahmad

Mechanisms of androgen receptor agonist- and antagonist-mediated cellular senescence in prostate cancer

Cancers (Basel)1218332020

10.3390/cancers12071833

Kregel

Bagamasbad

LaPensee

Raji

Brogley

Chinnaiyan

Cieslik

Robins

Differential modulation of the androgen receptor for prostate cancer therapy depends on the DNA response element

Nucleic Acids Res48474147552020

10.1093/nar/gkaa178

32198885

Ross

Bernstein

Lobo

Shimizu

Stanczyk

Pike

Henderson

5-alpha-reductase activity and risk of prostate cancer among Japanese and US white and black males

Lancet3398878891992

10.1016/0140-6736(92)90927-U

1348296

Makridakis

Ross

Pike

Chang

Stanczyk

Kolonel

Shi

Henderson

Reichardt

A prevalent missense substitution that modulates activity of prostatic steroid 5alpha-reductase

Cancer Res57102010221997

9067262

Ntais

Polycarpou

Ioannidis

SRD5A2 gene polymorphisms and the risk of prostate cancer: A meta-analysis

Cancer Epidemiol Biomarkers Prev126186242003

12869400

Reichardt

Makridakis

Henderson

Pike

Ross

Genetic variability of the human SRD5A2 gene: Implications for prostate cancer risk

Cancer Res55397339751995

7664265

Davis

Russell

Unusual length polymorphism in human steroid 5 alpha-reductase type 2 gene (SRD5A2)

Hum Mol Genet28201993

10.1093/hmg/2.6.820

8353504

Ruijter

van de Kaa

Miller

Ruiter

Debruyne

Schalken

Molecular genetics and epidemiology of prostate carcinoma

Endocr Rev2022451999

10.1210/edrv.20.1.0356

10047972

Makridakis

di Salle

Reichardt

Biochemical and pharmacogenetic dissection of human steroid 5 alpha-reductase type II

Pharmacogenetics104074132000

10.1097/00008571-200007000-00004

10898110

Hsing

Chen

Chokkalingam

Gao

Dightman

Nguyen

Deng

Cheng

Sesterhenn

Mostofi

Polymorphic markers in the SRD5A2 gene and prostate cancer risk: A population-based case-control study

Cancer Epidemiol Biomarkers Prev10107710822001

11588134

Makridakis

Ross

Pike

Crocitto

Kolonel

Pearce

Henderson

Reichardt

Association of mis-sense substitution in SRD5A2 gene with prostate cancer in African-American and Hispanic men in Los Angeles, USA

Lancet3549759781999

10.1016/S0140-6736(98)11282-5

10501358

Neslund-Dudas

Bock

Monaghan

Nock

Yang

Rundle

Tang

Rybicki

SRD5A2 and HSD3B2 polymorphisms are associated with prostate cancer risk and aggressiveness

Prostate67165416632007

10.1002/pros.20625

17823934

Russell

Wilson

Steroid 5 alpha-reductase: Two genes/two enzymes

Annu Rev Biochem6325611994

10.1146/annurev.bi.63.070194.000325

7979239

Huang

Chen

Zhang

Yan

Xie

Mao

Meta-analysis of three polymorphisms in the steroid-5-alpha-reductase, alpha polypeptide 2 gene (SRD5A2) and risk of prostate cancer

Mutagenesis263713832011

10.1093/mutage/geq103

21177315

Bentley

Callier

Rotimi

Diversity and inclusion in genomic research: Why the uneven progress?

J Community Genet82552662017

10.1007/s12687-017-0316-6

28770442

Moreno-Estrada

Gignoux

Fernández-López

Zakharia

Sikora

Contreras

Acuña-Alonzo

Sandoval

Eng

Romero-Hidalgo

Human genetics. The genetics of Mexico recapitulates Native American substructure and affects biomedical traits

Science344128012852014

10.1126/science.1251688

24926019

Silva-Zolezzi

Hidalgo-Miranda

Estrada-Gil

Fernandez-Lopez

Uribe-Figueroa

Contreras

Balam-Ortiz

del Bosque-Plata

Velazquez-Fernandez

Lara

Analysis of genomic diversity in Mexican Mestizo populations to develop genomic medicine in Mexico

Proc Natl Acad Sci USA106861186162009

10.1073/pnas.0903045106

19433783

Villarreal-Martínez

Gallardo-Blanco

Cerda-Flores

Torres-Muñoz

Gómez-Flores

Salas-Alanís

Ocampo-Candiani

Martínez-Garza

Candidate gene polymorphisms and risk of psoriasis: A pilot study

Exp Ther Med11121712222016

10.3892/etm.2016.3066

27073425

Patiño-García

Arroyo

Rangel-Villalobos

Soto-Vega

Velarde-Félix

Gabilondo

Sandoval-Ramirez

Figuera

Association between polymorphisms of the androgen and vitamin D receptor genes with prostate cancer risk in a Mexican population

Rev Invest Clin5925312007

17569297

Martinez-Fierro

Garza-Veloz

Rojas-Martinez

Ortiz-Lopez

Castruita-de la Rosa

Ortiz-Castro

Lazalde- Ramos

Cervantes-Villagrana

Castañeda-Lopez

Gomez-Guerra

Positive association between vascular endothelial growth factor (VEGF) −2578 C/A variant and prostate cancer

Cancer Biomark132352412013

10.3233/CBM-130348

24240584

Canto

Benítez Granados

Martínez Ramírez

Reyes

Feria-Bernal

García-García

Tejeda

Zavala

Tapia

Rojano-Mejía

Méndez

Genetic variants in ATP6 and ND3 mitochondrial genes are not associated with aggressive prostate cancer in Mexican-Mestizo men with overweight or obesity

Aging Male191871912016

10.1080/13685538.2016.1185409

27187822

Sanchez-Dominguez

Reyes-Lopez

Bustamante

Cerda-Flores

Villalobos-Torres Mdel

Gallardo- Blanco

Rojas-Martinez

Martinez-Rodriguez

Barrera-Saldaña

Ortiz-Lopez

The tumor necrosis factor alpha (−308 A/G) polymorphism is associated with cystic fibrosis in Mexican patients

PLoS One9e909452014

10.1371/journal.pone.0090945

24603877

Jaramillo-Rangel

Ortega-Martínez

Cerda-Flores

Barrera-Saldaña

C3435T polymorphism in the MDR1 gene and breast cancer risk in northeastern Mexico

Int J Clin Exp Pathol119049092018

31938182

Zhao

Song

Wang

Genetic model

J Cell Mol Med207652016

10.1111/jcmm.12751

26762596

Srigley

Delahunt

Samaratunga

Billis

Cheng

Clouston

Evans

Furusato

Kench

Leite

Controversial issues in Gleason and International Society of Urological Pathology (ISUP) prostate cancer grading: Proposed recommendations for international implementation

Pathology514634732019

10.1016/j.pathol.2019.05.001

31279442

Canto

Vilchis

Chávez

Mutchinick

Imperato-McGinley

Pérez-Palacios

Ulloa-Aguirre

Méndez

Mutations of the 5 alpha-reductase type 2 gene in eight Mexican patients from six different pedigrees with 5 alpha-reductase-2 deficiency

Clin Endocrinol (Oxf)461551601997

10.1046/j.1365-2265.1997.800904.x

9135696

Chávez

Valdez

Vilchis

Uniparental disomy in steroid 5alpha-reductase 2 deficiency

J Clin Endocrinol Metab85314731502000

10.1210/jc.85.9.3147

10999800

Vilchis

Valdez

Ramos

García

Gómez

Chávez

Novel compound heterozygous mutations in the SRD5A2 gene from 46, XY infants with ambiguous external genitalia

J Hum Genet534014062008

10.1007/s10038-008-0274-2

18350250

Shih

Graham

Review of genetic and environmental factors leading to hypospadias

Eur J Med Genet574534632014

10.1016/j.ejmg.2014.03.003

24657417

Zhou

Wang

Jin

Wang

Chen

Wang

Zhang

In-depth mining of clinical data: The construction of clinical prediction model with R

Ann Transl Med7632019

10.21037/atm.2019.08.63

30963058

Dong

Jiang

Zhang

Shen

Chen

Huang

Zheng

Development and validation of novel diagnostic models for biliary atresia in a large cohort of Chinese patients

EBioMedicine342232302018

10.1016/j.ebiom.2018.07.025

30077722

Sun

Nakayama

Dagdanpurev

Abe

Nishimura

Kirimoto

Matsui

Remote sensing of multiple vital signs using a CMOS camera-equipped infrared thermography system and its clinical application in rapidly screening patients with suspected infectious diseases

Int J Infect Dis551131172017

10.1016/j.ijid.2017.01.007

28093314

Shiota

Fujimoto

Yokomizo

Takeuchi

Kashiwagi

Dejima

Kiyoshima

Inokuchi

Tatsugami

Eto

The prognostic impact of serum testosterone during androgen- deprivation therapy in patients with metastatic prostate cancer and the SRD5A2 polymorphism

Prostate Cancer Prostatic Dis191911962016

10.1038/pcan.2016.2

26857022

Kusuma Duarsa

Sari

Gde Oka

Santosa

Yudiana

Wisnu Tirtayasa

Putra Pramana

Kloping

Serum testosterone and prostate-specific antigen levels are major risk factors for prostatic volume increase among benign prostatic hyperplasia patients

Asian J UrolJun72020(Epub ahead of print). doi: org/10.1016/j.ajur.2020.06.001

10.1016/j.ajur.2020.06.001

Golchin-Rad

Mogheiseh

Nazifi

Ahrari Khafi

Derakhshandeh

Abbaszadeh-Hasiri

Changes in the serum prostatic biomarkers during the treatment of benign prostatic hyperplasia with a 5alpha-REDUCTASE inhibitor: Finasteride

Top Companion Anim Med381004052020

10.1016/j.tcam.2020.100405

32115076

Gomez-Guerra

Martinez-Fierro

Alcantara-Aragon

Ortiz-Lopez

Martinez-Villarreal

Morales-Rodriguez

Garza-Guajardo

Ponce-Camacho

Rojas-Martinez

Population based prostate cancer screening in north Mexico reveals a high prevalence of aggressive tumors in detected cases

BMC Cancer9912009

10.1186/1471-2407-9-91

19317909

Lee

Giovannucci

Jeon

Diabetes and mortality in patients with prostate cancer: A meta-analysis

Springerplus515482016

10.1186/s40064-016-3233-y

27652121

Marrone

Selvin

Barber

Platz

Joshu

Hyperglycemia, classified with multiple biomarkers simultaneously in men without diabetes, and risk of fatal prostate cancer

Cancer Prev Res (Phila)121031122019

10.1158/1940-6207.CAPR-18-0216

30538098

Bansal

Bhansali

Kapil

Undela

Tiwari

Type 2 diabetes and risk of prostate cancer: A meta-analysis of observational studies

Prostate Cancer Prostatic Dis16151158, S12013

10.1038/pcan.2012.40

23032360

Lin

Garmo

Van Hemelrijck

Adolfsson

Stattin

Zethelius

Crawley

Association of type 2 diabetes mellitus and antidiabetic medication with risk of prostate cancer: A population-based case-control study

BMC Cancer205512020

10.1186/s12885-020-07036-4

32539807

Tseng

Metformin significantly reduces incident prostate cancer risk in Taiwanese men with type 2 diabetes mellitus

Eur J Cancer50283128372014

10.1016/j.ejca.2014.08.007

25201464

Azoulay

Dell'Aniello

Gagnon

Pollak

Suissa

Metformin and the incidence of prostate cancer in patients with type 2 diabetes

Cancer Epidemiol Biomarkers Prev203373442011

10.1158/1055-9965.EPI-10-0940

21148757

Häggström

Van Hemelrijck

Zethelius

Robinson

Grundmark

Holmberg

Gudbjörnsdottir

Garmo

Stattin

Prospective study of Type 2 diabetes mellitus, anti-diabetic drugs and risk of prostate cancer

International journal of cancer Journal international du cancer1406116172017

10.1002/ijc.30480

27770555

Garza-Guajardo

Delgado-Enciso

Melo-De-La-Garza

Rodriguez-Sanchez

Laura

Martinez-Fierro

Gómez-Guerra

Gómez-Macías

Barboza-Quintana

Guzmán-Esquivel

High fasting glucose, but not metabolic syndrome, is associated with elevated histologic aggressiveness in Mexican prostate cancer patients

Int J Clin Exp Pathol911951119572016

Plaskon

Penson

Vaughan

Stanford

Cigarette smoking and risk of prostate cancer in middle-aged men

Cancer Epidemiol Biomarkers Prev126046092003

12869398

Giovannucci

Smoking and aggressive prostate cancer: A review of the epidemiologic evidence

Cancer Causes Control20179918102009

10.1007/s10552-009-9387-y

19562492

Huncharek

Haddock

Reid

Kupelnick

Smoking as a risk factor for prostate cancer: A meta-analysis of 24 prospective cohort studies

Am J Public Health1006937012010

10.2105/AJPH.2008.150508

19608952

How Tobacco Smoke Causes Disease

The Biology and Behavioral Basis for Smoking-Attributable Disease

A Report of the Surgeon GeneralCenters for Disease Control and Prevention

Atlanta, GA

2010

Xue

Yang

Seng

Mechanisms of cancer induction by tobacco-specific NNK and NNN

Cancers (Basel)6113811562014

10.3390/cancers6021138

24830349

Baird

Hooven

Mahadevan

Carcinogenic polycyclic aromatic hydrocarbon-DNA adducts and mechanism of action

Environ Mol Mutagen451061142005

10.1002/em.20095

15688365

Zelikoff

Chen

Cohen

Schlesinger

The toxicology of inhaled woodsmoke

J Toxicol Environ Health B Crit Rev52692822002

10.1080/10937400290070062

12162869

IARC Working Group on the Evaluation of Carcinogenic Risk to Humans. Household Use of Solid Fuels and High-temperature Frying

Lyon (FR)

International Agency for Research on Cancer

2010(IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, No. 95.) 2, Studies of Cancer in Humanshttps://www.ncbi.nlm.nih.gov/books/NBK385519/

Luo

Jia

Zhou

Rapid determination of benzo(a)pyrene in processed meat and fish samples by second-derivative constant-energy synchronous fluorescence spectrometry

Food Addit Contam Part A Chem Anal Control Expo Risk Assess282352422011

10.1080/19440049.2010.535857

21181593

Bouaoun

Sonkin

Ardin

Hollstein

Byrnes

Zavadil

Olivier

TP53 Variations in human cancers: New lessons from the IARC TP53 database and genomics data

Hum Mutat378658762016

10.1002/humu.23035

27328919

Stellman

Demers

Colin

Boffetta

Cancer mortality and wood dust exposure among participants in the American Cancer Society Cancer Prevention Study-II (CPS-II)

Am J Ind Med342292371998

10.1002/(SICI)1097-0274(199809)34:3<229::AID-AJIM4>3.0.CO;2-Q

9698991

Chen

Cole

Grond-Ginsbach

Departure from Hardy Weinberg Equilibrium and genotyping error

Front Genet81672017

10.3389/fgene.2017.00167

29163635

McQuillan

Leutenegger

Abdel-Rahman

Franklin

Pericic

Barac-Lauc

Smolej-Narancic

Janicijevic

Polasek

Tenesa

Runs of homozygosity in European populations

Am J Hum Genet833593722008

10.1016/j.ajhg.2008.10.009

18760389

Paz-y-Miño

Witte

Robles

Llumipanta

Diaz

Arevalo

Association among polymorphisms in the steroid 5alpha-reductase type II (SRD5A2) gene, prostate cancer risk, and pathologic characteristics of prostate tumors in an Ecuadorian population

Cancer Genet Cytogenet18971762009

10.1016/j.cancergencyto.2008.09.012

19215786

Fang

Guo

Chen

Liu

Zeng

Wang

Relationship between SRD5A2 rs9282858 polymorphism and the susceptibility of prostate cancer: A meta-analysis based on 20 publications

Medicine (Baltimore)96e67912017

10.1097/MD.0000000000006791

28489754

Ribeiro

Santos

Carvalho-Salles

Hackel

Allelic frequencies of six polymorphic markers for risk of prostate cancer

Braz J Med Biol Res352052132002

10.1590/S0100-879X2002000200009

11847524

Pearce

Van Den Berg

Makridakis

Reichardt

Ross

Pike

Kolonel

Henderson

No association between the SRD5A2 gene A49T missense variant and prostate cancer risk: Lessons learned

Hum Mol Genet17245624612008

10.1093/hmg/ddn145

18469342

Mateo

Carreira

Sandhu

Miranda

Mossop

Perez-Lopez

Nava Rodrigues

Robinson

Omlin

Tunariu

DNA-Repair Defects and Olaparib in Metastatic Prostate Cancer

N Engl J Med373169717082015

10.1056/NEJMoa1506859

26510020

Ruscetti

PTEN in prostate cancer

Prostate Cancer871372013

10.1007/978-1-4614-6828-8_4

Ecke

Schlechte

Schiemenz

Sachs

Lenk

Rudolph

Loening

TP53 gene mutations in prostate cancer progression

Anticancer Res30157915862010

20592345

Loukola

Chadha

Penn

Rank

Conti

Thompson

Cicek

Love

Bivolarevic

Yang

Comprehensive evaluation of the association between prostate cancer and genotypes/haplotypes in CYP17A1, CYP3A4, and SRD5A2

Eur J Hum Genet123213322004

10.1038/sj.ejhg.5201101

14560315

Salam

Ursin

Skinner

Dessissa

Reichardt

Associations between polymorphisms in the steroid 5-alpha reductase type II (SRD5A2) gene and benign prostatic hyperplasia and prostate cancer

Urol Oncol232462532005

10.1016/j.urolonc.2004.12.014

16018939

Cussenot

Azzouzi

Nicolaiew

Mangin

Cormier

Fournier

Valeri

Cancel-Tassin

Low-activity V89L variant in SRD5A2 is associated with aggressive prostate cancer risk: An explanation for the adverse effects observed in chemoprevention trials using 5-alpha-reductase inhibitors

Eur Urol52108210872007

10.1016/j.eururo.2007.04.008

17448593

Sӧderstrӧm

Wadelius

Andersson

Johansson

Granath

Rane

5alpha-reductase 2 polymorphisms as risk factors in prostate cancer

Pharmacogenetics123073122002

10.1097/00008571-200206000-00006

12042668

LaTulippe

Satagopan

Smith

Scher

Scardino

Reuter

Gerald

Comprehensive gene expression analysis of prostate cancer reveals distinct transcriptional programs associated with metastatic disease

Cancer Res62449945062002

12154061

Chandran

Dhir

Bisceglia

Lyons-Weiler

Liang

Michalopoulos

Becich

Monzon

Gene expression profiles of prostate cancer reveal involvement of multiple molecular pathways in the metastatic process

BMC Cancer7642007

10.1186/1471-2407-7-64

17430594

Stanbrough

Bubley

Ross

Golub

Rubin

Penning

Febbo

Balk

Increased expression of genes converting adrenal androgens to testosterone in androgen-independent prostate cancer

Cancer Res66281528252006

10.1158/0008-5472.CAN-05-4000

16510604

Obinata

Takayama

Takahashi

Inoue

Crosstalk of the androgen receptor with transcriptional collaborators: Potential therapeutic targets for castration-resistant prostate cancer

Cancers (Basel)9222017

10.3390/cancers9030022

Squire

TMPRSS2-ERG and PTEN loss in prostate cancer

Nat Genet415095102009

10.1038/ng0509-509

19399032

Kiflemariam

Mignardi

Ali

Bergh

Nilsson

Sjoblom

In situ sequencing identifies TMPRSS2-ERG fusion transcripts, somatic point mutations and gene expression levels in prostate cancers

J Pathol2342532612014

24931216

Wang

Tang

Zhou

Liu

Yan

Guan

Chen

Prognostic value of androgen receptor splice variant 7 in the treatment of castration-resistant prostate cancer with next generation androgen receptor signal inhibition: A systematic review and meta-analysis

Eur Urol Focus45295392018

10.1016/j.euf.2017.01.004

28753843

Markowski

Silberstein

Eshleman

Eisenberger

Luo

Antonarakis

Clinical utility of CLIA-Grade AR-V7 testing in patients with metastatic castration-resistant prostate cancer

JCO Precis OncolOct102017(Epub ahead of print). doi: 10.1200/PO.17.00127, 2017

10.1200/PO.17.00127

Szklarczyk

Santos

von Mering

Jensen

Bork

Kuhn

STITCH 5: Augmenting protein-chemical interaction networks with tissue and affinity data

Nucleic Acids Res44D380D3842016

10.1093/nar/gkv1277

26590256

Shiota

Fujimoto

Yokomizo

Takeuchi

Itsumi

Inokuchi

Tatsugami

Uchiumi

Naito

SRD5A gene polymorphism in Japanese men predicts prognosis of metastatic prostate cancer with androgen-deprivation therapy

Eur J Cancer51196219692015

10.1016/j.ejca.2015.06.122

26169017

Torkko

van Bokhoven

Mai

Beuten

Balic

Byers

Hokanson

Norris

Barón

Lucia

VDR and SRD5A2 polymorphisms combine to increase risk for prostate cancer in both non-Hispanic White and Hispanic White men

Clin Cancer Res14322332292008

10.1158/1078-0432.CCR-07-4894

18483391

Zeng

Weng

Liu

Wang

Association between SRD5A2 rs523349 and rs9282858 polymorphisms and risk of benign prostatic hyperplasia: A meta-analysis

Front Physiol86882017

10.3389/fphys.2017.00688

28955247

Rył

Rotter

Grzywacz

Małecka

Skonieczna-Żydecka

Grzesiak

Słojewski

Szylińska

Sipak-Szmigiel

Piasecka

Molecular analysis of the SRD5A1 and SRD5A2 genes in patients with benign prostatic hyperplasia with regard to metabolic parameters and selected hormone levels

Int J Environ Res Public Health1413182017

10.3390/ijerph14111318

Huang

Wang

Tao

Tian

Chen

Jiao

Kang

Zheng

SRD5A1 and SRD5A2 are associated with treatment for benign prostatic hyperplasia with the combination of 5α-reductase inhibitors and α-adrenergic receptor antagonists

J Urol1906156192013

10.1016/j.juro.2013.03.024

23499746

Choubey

Sankhwar

Carlus

Singh

Dalela

Thangaraj

Rajender

SRD5A2 gene polymorphisms and the risk of benign prostatic hyperplasia but not prostate cancer

Asian Pac J Cancer Prev16103310362015

10.7314/APJCP.2015.16.3.1033

25735326

Figure 1.

Androgen receptor signaling axis. Testosterone enters prostate cells, where it is reduced to DHT by the action of the steroid 5α-reductase 2. Binding of DHT to the AR generates conformational changes that enable the dimerization of the AR and the subsequent binding to the androgen-response elements of androgen-responsive genes promoting cell proliferation. DHT, dihydrotestosterone; AR, androgen receptor.

Table I.

Clinical characteristics of the enrolled patients with prostate cancer.

Clinical characteristics	Prostate cancer cases, n (%)
ISUP grade group
Group 1	2 (2.0)
Group 2	13 (13.3)
Group 3	13 (13.3)
Group 4	9 (9.2)
Group 5	61 (62.2)
Extracapsular invasion	63 (62.4)
Neurovascular invasion	57 (56.4)
Recurrence	7 (6.9)
Metastasis	21 (20.8)
Castration-resistance	14 (13.9)
Androgen deprivation therapy
Bicalutamide	22 (32.8)
Bicalutamide + leuprolide	9 (13.4)
Bicalutamide + goserelin	11 (16.4)
Bicalutamide + orchiecthomy	12 (17.9)
Orchiectomy	6 (8.9)
Other^b	7 (10.4)

Group 1, Gleason Score <6; Group 2, Gleason Score=7(3+4); Group 3, Gleason Score=7(4+3); Group 4, Gleason Score=8; Group 5, Gleason Score=9 and 10.

Other treatments: Bicalutamide + leuprolide + orchiectomy, goserelin + leuprolide, zoledronic acid + leuprolide, goserelin, orchiectomy + docetaxel, and leuprolide + goserelin + ketoconazole + prednisolone. ISUP, International Society of Urological Pathology.

Table II.

Demographic characteristics of patients with PCa (n=101) and control subjects (n=100).

Demographic characteristic	PCa cases	Non-PCa cases	P-value	OR (95% CI)
Age, median years (IQR)	70 (64.5–75.0)	58.8 (48–67)	9.22×10⁻¹⁵	1.13 (1.08–1.17)
PSA, median ng/ml (IQR)	20.4 (9.65–62.82)	8.55 (5.12–17.71)	8.29×10⁻²⁰	1.11 (1.07–1.16)
BMI, median kg/m²	27.02 (±4.33)	27.84 (±5.52)	0.271	NS
BMI <18.5 (% underweight)	3.1	0.0	NA	NS
BMI 18.5–24.9, %	33.7	23.1	0.612	NS
BMI 25–29.9, %	40.8	44.9	0.226	NS
BMI >30, %	22.4	32.1	0.486	NS
Type 2 diabetes mellitus, %	20.8	21.0	0.732	NS
Arterial hypertension, %	38.6	33.0	0.694	NS
Alcohol intake, %	57.4	64.0	0.182	NS
Smoking habit, %	60.4	43.0	0.028	1.88 (1.07–3.31)
Biomass exposure, %	20.8	8.0	0.012	2.89 (1.21–6.88)
Family history of prostate cancer, %	18.8	12.0	0.224	NS
Family history of other cancers, %	33.7	29.0	0.603	NS

PCa, prostate cancer; OR, odds ratio; CI, confidence interval; IQR, interquartile range; PSA, prostate-specific antigen; BMI, body mass index; NA, not available; NS, not significant. P<0.05 indicates a statistically significant difference.

Table III.

Hardy-Weinberg equilibrium and genotype frequencies of A49T (rs9282858) and V89L (rs523349) variants in cases and controls.

		Fisher's HWE P-value		Genotype frequency

Variant	Reference alleles	Cases	Controls	Cases (%)	Controls (%)
A49T (rs9282858)	[C/T]	1.90E-06	0.005	T\|T: 0.030 (3)	T\|T: 0.010 (1)
				C\|C: 0.970 (98)	C\|C: 0.990 (97)
V89L (rs523349)	[C/G]	0.678	0.999	C\|C: 0.376 (38)	C\|C: 0.448 (44)
				C\|G: 0.455 (46)	C\|G: 0.439 (43)
				G\|G: 0.168 (17)	G\|G: 0.112 (11)

G, guanine; T, thymine, C, cytosine.

Table IV.

Association analysis of A49T and V89L variants.

					Allele frequency

Variant	Genetic model	χ² FDR	OR (95% CI)		Cases	Controls
A49T (rs9282858)	Dominant	0.327	T, 2.97 (0.30–29.05)	C, 0.34 (0.03–3.29)	T, 0.03	T, 0.01
	Recessive	0.327	T, 2.97 (0.30–29.05)	C, 0.34 (0.03–3.29)	C, 0.97	C, 0.99
V89L (rs523349)	Dominant	0.594	G, 1.35 (0.77–2.38)	C, 0.74 (0.42–1.30)	G, 0.396	G, 0.332
	Recessive	0.511	G, 1.60 (0.71–3.62)	C, 0.62 (0.28–1.41)	C, 0.604	C, 0.668

FDR, false discovery rate; OR, odds ratio; CI, confidence interval; G, guanine, T, thymine; C, cytosine.

Table V.

Analysis of rs523349 (V89L) genotypes and clinical features.

	PSA		Grade Gleason Group ISUP classification^a			Metastasis		Benign Prostatic Hyperplasia

Genotype	Median ng/ml	P-value	≤3	≥4	P-value	%	P-value	%	P-value
VV	48.46	0.684	14.28	23.47	0.071	3.96	0.492	20.60	0.282
VL	47.53		33.67	12.24		13.86		18.50
LL	53.22		14.28	2.04		2.97		3.30
VV+VL	51.07	0.655	26.50	57.10	0.125	17.82	0.766	39.10	0.3040
LL	47.53		2.04	14.30		2.97		3.30
VV	51.75	0.134	14.30	47.90	0.125	3.96	0.048	20.60	0.635
LL+VL	48.46		14.30	23.50		16.83		21.70

Group 1, Gleason score <6; Group 2, Gleason score=7 (3+4); Group 3, Gleason score=7 (4+3); Group 4, Gleason score=8; Group 5, Gleason score=9 and 10. PSA, prostate-specific antigen; ISUP, International Society of Urological Pathology; VV, val/val; VL, val/leu; LL, leu/leu.

Table VI.

Clinical effect of A49T (rs9282858) variant in other populations.

Authors, year	Population	Effect	Genotype(s)	Refs.
Makridakis et al, 1999	African-American	Associated to cancer development	Thr/Thr	(16)
Ribeiro et al, 2002	Brazilian	Not associated with cancer development	Thr/Thr	(65)
Pearce et al, 2008	Hispanic/African-American	Not associated with cancer development	Ala/Thr	(66)
Paz-y-Miño et al, 2009	Ecuadorian	Associated risk of prostate cancer	Thr/Thr vs. Ala/Thr	(63)
Fang et al, 2017	Latino	Associated with cancer development	Thr/Thr	(64)

Table VII.

Clinical effect of V89L (rs523349) variant in other populations.

Author, year	Population	Effect	Genotype(s)	Refs.
Makridakis et al, 1997	Asian	Protective against cancer	Leu/Leu	(9)
Sӧderstrӧm et al, 2002	Caucasian	Associated with metastasis	Leu/Leu	(73)
Loukola et al, 2004	European-Americans	Associated with cancer development	Leu/Leu vs. Val/Leu^a	(70)
Salam et al, 2005	Hispanic	Associated with cancer development	Leu/Leu	(71)
Cussenot et al, 2007	French	Gleason Scores >8	Leu/Leu	(72)
Torkko et al, 2008	Non-Hispanic White	Associated with cancer development	Val/Val^b	(84)
	Hispanic White	Associated with cancer development	Val/Val^c
Paz-y-Miño et al, 2009	Ecuadorian	Associated with cancer development	Val/Val	(63)

Analysis of genotyping results showed a HW disequilibrium

results combined with variants in VDR gene

results combined with variants in CDX2 gene.