Open Access

Inhibition mechanism of lung cancer cell metastasis through targeted regulation of Smad3 by miR‑15a

  • Authors:
    • Shuai Guo
    • Ming Li
    • Juan Li
    • Yan Lv
  • View Affiliations

  • Published online on: December 10, 2019     https://doi.org/10.3892/ol.2019.11194
  • Pages: 1516-1522
  • Copyright: © Guo et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

Effect of targeted regulation of mothers against decapentaplegic homolog 3 (Smad3) by microRNA-15a (miR‑15a) on the proliferation, invasion and metastasis of non‑small cell lung cancer (NSCLC) cells and its related mechanisms were investigated. Fifty pairs of NSCLC and para‑cancerous tissues were collected to identify the expression level of miR‑15a in NSCLC, para‑cancerous tissue, and cell lines A549, H1299, H1975 and BEAS‑2B by real‑time fluorescence quantitative PCR (RT‑PCR); A549 cells were transfected with miR‑15a mimic; the MTT assay was performed to detect the role of miR‑15a transfection in proliferation of A549 cells, the wound healing assay was carried out to identify the role of miR‑15a in migration of A549 cells; Transwell invasion assay was conducted to analyze the role of miR‑15a in invasion of A549 cells; western blotting was carried out to find the effect of miR‑15a on Smad3 expression, and Spearman's rank correlation was used to analyze the correlation between miR‑15a and Smad3 expression. NSCLC tissues and cells showed significantly lower miR‑15a expression, compared with para‑cancerous tissues and normal cell lines (P=0.023). miR‑15a was significantly more expressed in A549 cells transfected with miR‑15a mimic (P=0.043). Overexpression of miR‑15a can significantly inhibit A549 cell proliferation (P=0.038), migration (P=0.033) and invasion (P=0.025), and significantly reduced the expression level of Smad3 (P=0.031) in A549 cells. Spearman's rank correlation showed negative correlation of miR‑15a expression with Smad3, which may indicate negative regulation (r=‑0.34, P<0.0001). Inhibition of proliferation, migration and invasion of NSCLC cells can be achieved with targeted regulation of Smad3 by miR‑15a.

Introduction

Lung cancer is a leading contributor to cancer-related death worldwide. Non-small cell lung cancer (NSCLC) accounts for ~80% of all lung cancer cases, including squamous cell carcinoma and adenocarcinoma (1,2). Although great progress has been made in chemotherapy and surgery, NSCLC patients still have poor prognosis and a 5-year survival rate of <15% due to latent symptoms at the early stage and the high malignant potential of NSCLC (3). Therefore, to improve clinical efficacy of NSCLC therapies, it is necessary to seek biomarkers involved in the occurrence and development of NSCLC and clarify the pathogenesis of NSCLC.

MicroRNA (miRNA) is an endogenous non-coding RNA (4) that regulates gene expression at the post-transcriptional level by binding to the 3′- untranslated region (3′-UTR) of target mRNA (5). miRNA participates in a variety of biological processes, including cell proliferation, differentiation, invasion, angiogenesis and apoptosis (6). Abnormal expression of miRNA has been reported to play a critical role in the occurrence and development of tumors. Wan et al (7) suggested that miR-27b expression is notably downregulated in NSCLC tissues and cells, and expression of LIMK1 is upregulated to inhibit the proliferation and invasion of tumors. miR-205 can be used as a new therapeutic target due to its downregulation in glioma and its inhibition of the migration and invasion of tumor cells through targeting YAP1. The latest evidence links many miRNAs to the regulation of the occurrence and progression of NSCLC (8), and the abnormally expressed miRNA is involved in tumor progression in NSCLC as an oncogene or tumor inhibiting factor (9). Despite the headway in research on miRNA in NSCLC, the relationship between them has not been well-established and requires further efforts. miR-15a-3p is found downregulated in cervical cancer while it inhibits tumor cell proliferation, induces cell apoptosis, and raises the sensitivity of tumor cells to radiotherapy by regulating TPD (10). Jin et al (11) found that miR-15a may be a molecular therapeutic target for thyroid cancer, which inhibits RET/AKT signaling pathways to inhibit metastasis and invasion of thyroid cancer However, the effect of miR-15a on the biological function of NSCLC and its mechanism of action in NSCLC are still unclear.

The current study focused on the role of miR-15a in NSCLC metastasis and in the proliferation, metastasis and invasion of NSCLC by targeted-regulating of mothers against decapitaplegic homolog3 (Smad3) expression, providing fundamental theoretical basis for further understanding the occurrence and development mechanism of NSCLC and prognosis evaluation of NSCLC patients.

Materials and methods

Main reagents, instruments and cell lines

Annexin V-FITC, MTT kits, and HRP-labeled Goat Anti-Rabbit IgG (A0208) were from Beyotime Biotechnology; RPMI-1640 medium, fetal bovine serum, penicillin-streptomycin and trypsin from Gibco; Thermo Fisher Scientific, Inc.; TRIzol reagent and Transwell cell culture plates from Corning Inc.; Promega M-MLV reverse transcription kits from Promega Corporation; YBR Premix Ex Taq from Takara Biotechnology Co., Ltd.; miR-15a overexpression plasmid was synthesized by Guangzhou RiboBio Co., Ltd.; Lipofectamine® 3000 Transfection kit was from Invitrogen; Thermo Fisher Scientific, Inc.; Smad3 protein (rabbit anti-human Smad3 monoclonal antibody, ab40854) from Abcam; GAPDH antibody (mouse anti-human GAPDH monoclonal antibody, SC-32233) from Santa Cruz Biotechnology, Inc.; Immobilon Western HRP from Thermo Fisher Scientific, Inc.

Human NSCLC cell lines (A549, H1299, and H1975) and the normal lung cells (BEAS-2B) were all from Shanghai Institute of Biochemistry and Cell Biology, CAS. The cells were cultured in DMEM (Corning Inc.) medium containing 10% fetal bovine serum (FBS) (Thermo Fisher Scientific, Inc.) and 1% streptomycin (Corning Inc.) at 37°C with the concentration of 5% CO2.

Clinical specimens

Fifty patients with NSCLC who underwent surgical treatment in the thoracic surgery department of Shandong Provincial Chest Hospital (Jinan, China) between January 2016 and December 2018 were enrolled. Inclusion criteria: The patients received surgical treatment in the above hospital and had primary lesions, and all specimens were pathologically confirmed as NSCLC. Exclusion criteria: those who received radiotherapy, chemotherapy or interventional therapies before treatment, and those who had other metastases before treatment. Tumor tissues and para-cancerous tissue of NSCLC patients were collected (2 cm away from tumor). The specimens were stored in a liquid nitrogen container 10 min after surgery in vitro for subsequent steps. The study was examined and approved by the Ethics Committee of Shandong Provincial Chest Hospital. Signed informed consents were obtained from the patients and/or the guardians.

Cell culture and transfection

FBS, penicillin-streptomycin, and RPMI-1640 basal medium were prepared into RMPI-1640 complete medium with 10% FBS and 1% penicillin-streptomycin. The cells were cultured at 37°C with the concentration of 5% CO2. The cells were inoculated in a 6-well plate with an inoculation density of ~2.5×106 cells/well, and incubated in a constant temperature incubator. Logarithmically growing cells were chosen and inoculated in a culture plate, the cell confluence was ~80% before transfection. The cells were divided into the empty plasmid group (miR-NC group), and the transfection simulation sequence group (5′-CTCAACTGGTGTCGTGGAGTC-3′) (miR-15a mimic group). After 36 h of transfection, the cells were trypsinized and then collected for subsequent steps.

Detection of the expression level of miR-15a mRNA before and after transfection via RT-PCR

Total RNA was extracted from tissues and cells using TRIzol reagent, quantitatively detected in terms of content with an ultraviolet spectrophotometer, and then reverse transcribed to obtain cDNA and the transcribed cDNA was amplified by RT-PCR. The primer sequences are shown in Table I. RT-PCR reactions were performed with 10 µl SYBR Premix Ex Taq, 0.4 µl forward primer, 0.4 µl reverse primer, 2 µl cDNA, and 7.2 µl sterilized distilled water. Pre-denaturation lasted for 10 min at 95°C, denaturation for 30 sec at 95°C, annealing for 30 sec at 60°C and extension for 30 sec at 74°C. The circle was repeated 40 times.

Table I.

Primer sequences.

Table I.

Primer sequences.

PrimerPrimer sequence
GAPDHF, 5′-GTGGACCTCATGCTACAT-3′
R, 5′-TGTGAGGGAGATGCTCAGTG-3′
miR-15aF, 5′-TCCAGCTGGCAGCATG-3′
R, 5′-GTCGTGGAGTCACTCG-3′

[i] F, forward; R, reverse.

Detection of the proliferation of tumor cells via the MTT assay

Trypsinization was carried out 36 h post transfection to collect cells of each group, and then the cells were inoculated in 96-well plates with 5×103 cells/well, respectively. OD value was measured at 490 nm 4 h after 20 µl of MTT solution was added to each well at days 2, 3, 4 and 5 of inoculation, and a cell growth curve was plotted. The trial was repeated 3 times taking the average OD value. The cell growth inhibitory concentration (IC) = (1 - average OD value of miR-15a mimic group / average OD value of miR-NC group) × 100%.

Detection of the migration of tumor cells via wound healing assay

The cells in the logarithmic growth phase were cultured until confluence of 80%, and gently pushed to generate wounds on the surface. Then PBS was used to wash the cells 3 times. Complete medium was replaced, recording the wounds and the cell culture was continued. After 24 h of culture, the wounds were photographed and recorded to compare their width, and to statistically analyze the cell migration of each group.

Detection of the invasion of tumor cells via Transwell invasion assay

Trypsinization was carried out 36 h post transfection to collect cells of each group, and then the cells were inoculated in 24-well plates with 5×103 cells/well, respectively. Serum-free medium (200 µl) containing penicillin-streptomycin was added to the upper layer of Transwell cell culture insert, and 400 µl of complete culture medium containing 10% FBS and 1% penicillin-streptomycin to the lower layer, to culture the cells for 12 h at 37°C with the concentration of 5% CO2. The cell culture insert was then washed 3 times with PBS to remove non-migrated cells. The cells were fixed with 4% paraformaldehyde solution for 10 min, and then washed with PBS 3 times. Subsequently, the cells were dyed with 0.5% crystal violet solution for 10–15 min and rinsed with PBS 3 times. The final step was to count migrated cells. The trial was repeated 3 times to average the values.

Prediction of the miR-15a target gene

Prediction of the human miR-15a target genes on TargetScan (http://www.Targetscan.org) showed that the higher the score of the binding of mRNA to miR-15a seed region, the greater the possibility of the binding.

Detection of the expression level of Smad3 protein via western blotting

Precooled 1X PBS was used to collect and wash the cells twice; the cells were centrifuged at 1,200 × g at 4°C for 5 min, precipitated, and lysed with 100 RIPA lysate. After centrifugation, the cells were isolated by adding 10 µl of protein to 10% polyacrylamide gel. The isolated protein was transferred onto the PVDF membrane by a wet transfer method (current 300 mA, 1.5 h) and then sealed at room temperature for 1 h before western blotting was carried out. Primary Smad3 protein and GAPDH antibody were diluted at 1:2,000 with 5% fat-free milk, and hybridized overnight at 4°C, and the PVDF membrane was washed 3 times with 1X PBST for 5 min each time. The second antibody was diluted at 1:5,000 with 5% fat-free milk powder, and incubated for 2 h at room temperature. The PVDF membrane was washed 3 times with 1X PBST for 5 min each time. ECL luminescent solution was prepared, developed and exposed. Then, the strip quantitative analysis was performed (Gelpro Analyzer, Media Cybernetics, Inc.).

Statistical analysis

IBM SPSS Statistics 20.0 was used to make statistical analysis of the collected data, with GraphPad Prism 8 to draw statistical charts. All data were obtained by 3 independent trials. The measurement data were expressed as the mean ± standard deviation (mean ± SD), whereas the count data were represented as a percentage (%). The t-test was used to analyze the differences between the two groups, variance analysis for differences among groups, and Pearson's correlation coefficient for the correlation between variables. P<0.05 was considered to indicate a statistically significant difference.

Results

Expression level of miR-15a mRNA in NSCLC tissues and cells

RT-PCR results showed that expression of miR-15a mRNA was significantly lower in NSCLC tissue (P=0.023) compared with para-carcinoma tissues (Fig. 1A). Expression level of miR-15a mRNA was detected in three NSCL cell lines (H1975, A549, and H1299) and in normal lung cells (BEAS-2B), and it was found that expression of miR-15a mRNA was significantly lower in NSCLC cell lines than that in the normal lung cells (P<0.05) (Fig. 1B).

Expression level of miR-15a mRNA in A549 cells after transfection

A549 cells with the lowest relative expression of miR-15a were transfected with miR-15a mimic. RT-PCR indicated significantly higher expression level of miR-15a mRNA in A549 cells relative to miR-NC group after transfection (Fig. 2). The difference was statistically significant (P=0.043). The results showed that the tumor cell models were successfully transfected with miR-15a and could be used in subsequent trials.

Overexpression of miR-15a significantly inhibits the proliferation of NSCLC cells

Via the MTT assay, it was found that compared with miR-NC group, A549 cells which were transfected with miR-15a mimic had significantly reduced cell viability and proliferation significantly slowed down on the 2nd, 3rd, 4th and 5th days after adding MTT solution (P=0.038). This indicated that miR-15a could significantly inhibit the proliferation of NSCLC cell lines (Fig. 3).

Effect of miR-15a overexpression on migration and invasion of NSCLC

The wound healing assay showed that A549 cells had significantly reduced migration than miR-NC group after transfection of miR-15a mimic, and the difference was statistically significant (P=0.033). It suggested that overexpression of miR-15a can significantly inhibit the migration of NSCLC cell lines (Fig. 4A). According to the Transwell invasion assay, the cell invasion of miR-15a mimic group was significantly reduced in comparison with that of miR-NC group (P=0.025), indicating significant inhibition of the invasion ability of NSCLC cell line by miR-15a overexpression (Fig. 4B). The above showed that overexpression of miR-15a may weaken the cell migration and invasion of A549 cells, and inhibit tumor cell metastasis.

miR-15a regulates Smad3 protein expression

Bioinformatics analysis predicted the binding sites of miR-15a on Smad3 (Fig. 5A). Western blotting results showed that miR-15a was overexpressed in A549 cells, significantly reducing the expression level of Smad3 protein (P=0.031) (Fig. 5B and C). Pearson correlation analysis showed that miR-15a mRNA level was significantly negatively correlated with Smad3 expression level, suggesting that miR-15a and Smad3 may have negative regulatory relationships (r=−0.34, P<0.0001) (Fig. 5D).

Discussion

In this study, NSCLC cell lines were transfected with miR-15a to investigate the function of miR-15a in the occurrence and development of NSCLC. It was found that miR-15a served as a tumor inhibiting factor in NSCLC. Overexpression of miR-15a inhibited cell proliferation, migration and invasion of NSCLC. The findings showed that Smad3 is a target gene of miR-15a in NSCLC.

miRNA is an endogenous non-coding small RNA, which can bind to 3′-UTR of target mRNA to inhibit transcription of target genes or degrade target mRNA fragments, and regulate its expression at a post-transcription level (9,12). Increasing evidence links miRNA to occurrence and development of cancers (13). Due to organ specificity, miRNA differs in different organs in terms of types and proportions. miRNAs are related to the functional regulation of organs, so miRNAs can be used as specific biological markers for many different diseases. Therefore, research on the role of NSCLC-specific miRNAs in its occurrence and development process can provide new insights into the study of the occurrence and development of NSCLC as well as new schemes for clinical treatment of NSCLC.

The miR-15a gene is located at human chromosome 13q14 and was first reported to be abnormally expressed in cancer in 2002. The deletion of miR-15a is associated with poor prognosis of patients with chronic lymphocytic leukemia (14,15). miR-15a is the first miRNA reported to be involved in tumor development, which is of great significance. Subsequent studies have reported the expression and mechanism of miR-15a in tumors. miR-15a, as a tumor inhibiting factor, is downregulated in melanoma, colorectal cancer, bladder cancer, prostate cancer and other solid tumors (1619). MicroRNA-15 (miR-15) family, as upstream regulatory molecules, regulates different target mRNAs and plays a crucial role in the occurrence and development of tumors. Janaki Ramaiah et al (20) found that miR-15 inhibits the proliferation of breast cancer cells and induces apoptosis by targeting p70S6 kinase. Pouliot et al (21) screened miRNA using high-throughput screening to restore the sensitivity of cisplatin-resistant cells. It was found that targeted regulating of the expression of Wee1 and CHK1 by miR-15a could restore the sensitivity of cisplatin-resistant cells. Bozok et al (22) and Çalışkan et al (23) confirmed that miR-15a enhanced the anti-tumor effect of platinum chemotherapeutic drugs in drug-resistant NSCLC. In other studies, miRNA-15 family suppressed cell metastasis by regulating EMT process in malignant cancer cells (2426). He (27) found that knockout of miR-15a may promote proliferation and invasion of lung cancer cells, inhibit cell apoptosis, and induce EMT. In this study, miR-15a was found expressed at significantly lower level in NSCLC tissues by comparison with that in para-carcinoma tissues. miR-15a expression was also relatively low in NSCLC cell lines in in vitro cell trials, indicating that the low expression of miR-15a may promote the occurrence of NSCLC. In addition, based on the expression of miR-15a in the three NSCLC cell lines, A549 cell line with the lowest miR-15a expression was transfected with miR-15a mimic to construct a NSCLC cell line model with overexpression of miR-15a. Metastasis is one of the most important malignant biological characteristics of tumor cells. It was found herein through wound healing assay and Transwell invasion assay that overexpression of miR-15 effectively inhibited the migration and invasion ability of NSCLC cells. Combined with previous studies, it was shown that miR-15a has universal anti-tumor effect on a variety of tumors. Its anti-tumor mechanism is not related to the origin of tumor tissue and has potential clinical development value. This drove the research team to find how miR-15a regulates the migration and invasion of NSCLC cells.

It is predicted on online bioinformatics databases (Pictar, Targetscan, miRanda) that miR-15a may be one of the genes regulating transforming growth factor-β (TGF-β) signal pathways, and may be bound to 3′UTR of Smad3. As a main transcription factor of TGF-β signal transduction, Smad3 acts as a tumor inhibiting factor and oncogene in the process of tumor occurrence and development. TGF-β signaling pathways participate in normal physiological processes such as growth and development, inflammatory responses, and immune regulation, as well as in tumor development. Jin et al (18) found that miR-15a/16 inhibits prostate cancer metastasis and invasion by inhibiting TGF-β signaling pathways. Underexpression or mutation of Smad3 will lead to interruption of TGF-β signaling, making cells beyond the growth inhibition of TGF-β signal pathways and eventually develop into tumor cells (2830). Previous studies have shown that Smad3, as a negative growth signal regulator, regulates the expression of TGF-β superfamily during the occurrence and development of varying tumors, accommodates the abnormal growth cycle of cells and protects the body (31,32). In this study, western blotting and Pearson's correlation coefficient showed that overexpression of miR-15a significantly reduced the expression of Smad3, and the two had negative regulatory correlation. Combined with in vitro cell trial, it was shown that miR-15a can target downregulation of Smad3 to inhibit the proliferation and metastasis of NSCLC cells.

In conclusion, it was found that miR-15a is differentially expressed in NSCLC tissues and cells. miR-15a may inhibit the proliferation, migration and invasion of NSCLC cells through targeted regulation of Smad3 expression. This provides theoretical basis for the pathogenesis of NSCLC. miR-15a is expected to become a potential new target for NSCLC biotherapies.

Acknowledgements

Not applicable.

Funding

No funding was received.

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

SG detected the migration of tumor cells via wound healing assay and wrote the manuscript, ML interpreted and analyzed the data. JL designed the study and performed the experiment. YL was responsible for the analysis and discussion of the data. All authors read and approved the final manuscript.

Ethics approval and consent to participate

The study was approved by the Ethics Committee of Shandong Provincial Chest Hospital (Jinan, China). Patients who participated in this study had complete clinical data. Signed informed consents were obtained from the patients and/or the guardians.

Patient consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

References

1 

Ferlay J, Shin HR, Bray F, Forman D, Mathers C and Parkin DM: Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int J Cancer. 127:2893–2917. 2010. View Article : Google Scholar : PubMed/NCBI

2 

Siegel RL, Miller KD and Jemal A: Cancer statistics, 2019. CA Cancer J Clin. 69:7–34. 2019. View Article : Google Scholar : PubMed/NCBI

3 

van Klaveren RJ: Lung cancer screening. Eur J Cancer. 47 (Suppl 3):S147–S155. 2011. View Article : Google Scholar : PubMed/NCBI

4 

Bartel DP: MicroRNAs: Genomics, biogenesis, mechanism, and function. Cell. 116:281–297. 2004. View Article : Google Scholar : PubMed/NCBI

5 

Bouyssou JM, Manier S, Huynh D, Issa S, Roccaro AM and Ghobrial IM: Regulation of microRNAs in cancer metastasis. Biochim Biophys Acta. 1845:255–265. 2014.PubMed/NCBI

6 

Zagryazhskaya A and Zhivotovsky B: miRNAs in lung cancer: A link to aging. Ageing Res Rev. 17:54–67. 2014. View Article : Google Scholar : PubMed/NCBI

7 

Wan L, Zhang L, Fan K and Wang J: miR-27b targets LIMK1 to inhibit growth and invasion of NSCLC cells. Mol Cell Biochem. 390:85–91. 2014. View Article : Google Scholar : PubMed/NCBI

8 

Zhan M, Qu Q, Wang G and Zhou H: Let-7c sensitizes acquired cisplatin-resistant A549 cells by targeting ABCC2 and Bcl-XL. Pharmazie. 68:955–961. 2013.PubMed/NCBI

9 

Zhang N, Wei X and Xu L: miR-150 promotes the proliferation of lung cancer cells by targeting P53. FEBS Lett. 587:2346–2351. 2013. View Article : Google Scholar : PubMed/NCBI

10 

Wu Y, Huang J, Xu H and Gong Z: Over-expression of miR-15a-3p enhances the radiosensitivity of cervical cancer by targeting tumor protein D52. Biomed Pharmacother. 105:1325–1334. 2018. View Article : Google Scholar : PubMed/NCBI

11 

Jin J, Zhang J, Xue Y, Luo L, Wang S and Tian H: miRNA-15a regulates the proliferation and apoptosis of papillary thyroid carcinoma via regulating AKT pathway. OncoTargets Ther. 12:6217–6226. 2019. View Article : Google Scholar

12 

Molina-Pinelo S, Gutiérrez G, Pastor MD, Hergueta M, Moreno-Bueno G, García-Carbonero R, Nogal A, Suárez R, Salinas A, Pozo-Rodríguez F, et al: MicroRNA-dependent regulation of transcription in non-small cell lung cancer. PLoS One. 9:e905242014. View Article : Google Scholar : PubMed/NCBI

13 

O'Connell RM, Rao DS, Chaudhuri AA and Baltimore D: Physiological and pathological roles for microRNAs in the immune system. Nat Rev Immunol. 10:111–122. 2010. View Article : Google Scholar : PubMed/NCBI

14 

Codony C, Crespo M, Abrisqueta P, Montserrat E and Bosch F: Gene expression profiling in chronic lymphocytic leukaemia. Best Pract Res Clin Haematol. 22:211–222. 2009. View Article : Google Scholar : PubMed/NCBI

15 

Pekarsky Y and Croce CM: Role of miR-15/16 in CLL. Cell Death Differ. 22:6–11. 2015. View Article : Google Scholar : PubMed/NCBI

16 

Aqeilan RI, Calin GA and Croce CM: miR-15a and miR-16-1 in cancer: Discovery, function and future perspectives. Cell Death Differ. 17:215–220. 2010. View Article : Google Scholar : PubMed/NCBI

17 

Musumeci M, Coppola V, Addario A, Patrizii M, Maugeri-Saccà M, Memeo L, Colarossi C, Francescangeli F, Biffoni M, Collura D, et al: Control of tumor and microenvironment cross-talk by miR-15a and miR-16 in prostate cancer. Oncogene. 30:4231–4242. 2011. View Article : Google Scholar : PubMed/NCBI

18 

Jin W, Chen F, Wang K, Song Y, Fei X and Wu B: miR-15a/miR-16 cluster inhibits invasion of prostate cancer cells by suppressing TGF-β signaling pathway. Biomed Pharmacother. 104:637–644. 2018. View Article : Google Scholar : PubMed/NCBI

19 

Bonci D, Coppola V, Musumeci M, Addario A, Giuffrida R, Memeo L, D'Urso L, Pagliuca A, Biffoni M, Labbaye C, et al: The miR-15a-miR-16-1 cluster controls prostate cancer by targeting multiple oncogenic activities. Nat Med. 14:1271–1277. 2008. View Article : Google Scholar : PubMed/NCBI

20 

Janaki Ramaiah M, Lavanya A, Honarpisheh M, Zarea M, Bhadra U and Bhadra MP: miR-15/16 complex targets p70S6 kinase 1 and controls cell proliferation in MDA-MB-231 breast cancer cells. Gene. 552:255–264. 2014. View Article : Google Scholar : PubMed/NCBI

21 

Pouliot LM, Chen YC, Bai J, Guha R, Martin SE, Gottesman MM and Hall MD: Cisplatin sensitivity mediated by WEE1 and CHK1 is mediated by miR-155 and the miR-15 family. Cancer Res. 72:5945–5955. 2012. View Article : Google Scholar : PubMed/NCBI

22 

Bozok Çetintaş V, Tetik Vardarlı A, Düzgün Z, Tezcanlı Kaymaz B, Açıkgöz E, Aktuğ H, Kosova Can B, Gündüz C and Eroğlu Z: miR-15a enhances the anticancer effects of cisplatin in the resistant non-small cell lung cancer cells. Tumour Biol. 37:1739–1751. 2016. View Article : Google Scholar : PubMed/NCBI

23 

Çalışkan M, Güler H and Bozok Çetintaş V: Current updates on microRNAs as regulators of chemoresistance. Biomed Pharmacother. 95:1000–1012. 2017. View Article : Google Scholar : PubMed/NCBI

24 

Renjie W and Haiqian L: miR-132, miR-15a and miR-16 synergistically inhibit pituitary tumor cell proliferation, invasion and migration by targeting Sox5. Cancer Lett. 356B:568–578. 2015. View Article : Google Scholar

25 

Shi L, Jackstadt R, Siemens H, Li H, Kirchner T and Hermeking H: p53-induced miR-15a/16-1 and AP4 form a double-negative feedback loop to regulate epithelial-mesenchymal transition and metastasis in colorectal cancer. Cancer Res. 74:532–542. 2014. View Article : Google Scholar : PubMed/NCBI

26 

Gao W, Wang Y, Wang W and Shi L: The first multiplication atom-bond connectivity index of molecular structures in drugs. Saudi Pharm J. 25:548–555. 2017. View Article : Google Scholar : PubMed/NCBI

27 

He J: Knocking down miR-15a expression promotes the occurrence and development and induces the EMT of NSCLC cells in vitro. Saudi J Biol Sci. 24:1859–1865. 2017. View Article : Google Scholar : PubMed/NCBI

28 

Li H, Xu D, Toh BH and Liu JP: TGF-beta and cancer: Is Smad3 a repressor of hTERT gene? Cell Res. 16:169–173. 2006. View Article : Google Scholar : PubMed/NCBI

29 

Xu W, Zeng F, Li S, Li G, Lai X, Wang QJ and Deng F: Crosstalk of protein kinase C ε with Smad2/3 promotes tumor cell proliferation in prostate cancer cells by enhancing aerobic glycolysis. Cell Mol Life Sci. 75:4583–4598. 2018. View Article : Google Scholar : PubMed/NCBI

30 

Paul D, Dixit A, Srivastava A, Tripathi M, Prakash D, Sarkar C, Ramanujam B, Banerjee J and Chandra PS: Altered transforming growth factor beta/SMAD3 signalling in patients with hippocampal sclerosis. Epilepsy Res. 146:144–150. 2018. View Article : Google Scholar : PubMed/NCBI

31 

Ooshima A, Park J and Kim SJ: Phosphorylation status at Smad3 linker region modulates transforming growth factor-β-induced epithelial-mesenchymal transition and cancer progression. Cancer Sci. 110:481–488. 2019. View Article : Google Scholar : PubMed/NCBI

32 

Wang Y, Xiang J, Wang J and Ji Y: Downregulation of TGF-β1 suppressed proliferation and increased chemosensitivity of ovarian cancer cells by promoting BRCA1/Smad3 signaling. Biol Res. 51:582018. View Article : Google Scholar : PubMed/NCBI

Related Articles

Journal Cover

February-2020
Volume 19 Issue 2

Print ISSN: 1792-1074
Online ISSN:1792-1082

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
x
Spandidos Publications style
Guo S, Li M, Li J and Lv Y: Inhibition mechanism of lung cancer cell metastasis through targeted regulation of Smad3 by miR‑15a. Oncol Lett 19: 1516-1522, 2020
APA
Guo, S., Li, M., Li, J., & Lv, Y. (2020). Inhibition mechanism of lung cancer cell metastasis through targeted regulation of Smad3 by miR‑15a. Oncology Letters, 19, 1516-1522. https://doi.org/10.3892/ol.2019.11194
MLA
Guo, S., Li, M., Li, J., Lv, Y."Inhibition mechanism of lung cancer cell metastasis through targeted regulation of Smad3 by miR‑15a". Oncology Letters 19.2 (2020): 1516-1522.
Chicago
Guo, S., Li, M., Li, J., Lv, Y."Inhibition mechanism of lung cancer cell metastasis through targeted regulation of Smad3 by miR‑15a". Oncology Letters 19, no. 2 (2020): 1516-1522. https://doi.org/10.3892/ol.2019.11194