Upregulation of miR-137 reverses sorafenib resistance and cancer-initiating cell phenotypes by degrading ANT2 in hepatocellular carcinoma

  • Authors:
    • Ai-Qing Lu
    • Bin Lv
    • Fei Qiu
    • Xiao-Yun Wang
    • Xiao-Hua Cao
  • View Affiliations

  • Published online on: March 10, 2017     https://doi.org/10.3892/or.2017.5498
  • Pages: 2071-2078
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Abstract

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. More than 80% of patients with HCC are not good candidates for curative surgical resection due to advanced liver cirrhosis caused by underlying chronic hepatitis virus (B or C) infection. Sorafenib, an oral multikinase inhibitor, is the only approved agent for the treatment of advanced HCC. Although, sorafenib currently sets the new standard for advanced HCC treatment, tumor response rates are usually quite low. An understanding of the underlying mechanisms for sorafenib resistance is critical. In the present study, we found that adenine nucleotide translocator 2 (ANT2) was upregulated in sorafenib‑resistant HCC Huh7 cells (Huh7-R) and its overexpression promoted sorafenib resistance. ANT2 induced the formation of cancer-initiating cell (CIC) phenotypes and promoted metastasis-associated traits in the Huh7 cells. Silencing of miR-137 upregulated ANT2 protein expression in the Huh7 cells. miR-137 was downregulated in the Huh7-R cells, compared with that in the Huh7 cells and its restoration reversed sorafenib resistance in the Huh7-R cells. Restoration of miR-137 inhibited formation of CIC traits and attenuated the abilities of migration and invasion in the Huh7-R cells. Moreover, we demonstrated that high-intensity focused ultrasound (HIFU) in unresectable HCC upregulated serum miR-137. Combining HIFU and sorafenib may be a wise option for advanced and unresectable HCC.

Introduction

Hepatocellular carcinoma (HCC) is the most common liver cancer, accounting for 90% of primary liver cancers and is currently the third major cause of cancer-related deaths worldwide (1). Although, recent progress in diagnostic and treatment technologies has improved survival, the long-term survival of HCC patients remains dismal. One of the reasons for the dismal prognosis is that current treatment cannot eliminate cancer-initiating cells (CICs) (2,3). A comprehensive understanding of the molecular basis of CICs of HCC may contribute to the identification of novel therapeutic targets to improve patient outcome.

Sorafenib (Nexavar), a multiple kinase inhibitor, is the first and only drug that is clinically approved for patients with advanced HCC (48). The major target of sorafenib is serine threonine kinase Raf-1, which is involved in the Ras/Raf/MEK/mitogen-activated protein kinase signaling cascade (9,10). In an in vitro kinase assay, sorafenib efficiently inhibited the activity of Raf-1 at a very low dose (IC50 of 6 nM) (11,12). Other receptor tyrosine kinases are also suppressed by sorafenib, including vascular endothelial growth factor receptors 1, 2 and 3, platelet-derived growth factor receptor and fibroblast growth factor receptor (12,13). Although, sorafenib has exhibited survival benefits in large randomized phase III studies, the response rate to sorafenib is actually quite low (2–3%) (4,14). In addition, therapeutic biomarkers that may predict the response to sorafenib are not currently available. Therefore, to improve the treatment response in HCC, it is important to identify the molecular mechanism of sorafenib resistance.

Adenine nucleotide translocator (ANT) which is abundant in the inner mitochondrial membrane, plays an important role in cellular energy metabolism by catalyzing the exchange of mitochondrial adenosine triphosphate for cytosolic adenosine diphosphate, thus, influencing mitochondrial bioenergetics (15). In addition, it is involved in the formation of the mitochondrial permeability transition pore complex that interacts with the Bcl2 family of proteins, contributing to mitochondrial-mediated apoptosis (16). Human ANT has 4 isoforms (ANT1, ANT2, ANT3 and ANT4), and the relative expression of these isoforms is dependent on the developmental stage, proliferation status and cell or tissue types. Among these isoforms, ANT2 is specifically expressed in proliferative and undifferentiated cells (16). It has been reported that ANT2 suppression by shRNA can exert anticancer effects in HCC through the regulation of different pathways (1719).

High-intensity focused ultrasound (HIFU) is based on the unique characteristic of ultrasound beams (0.8–3.5 MHz), which can be focused at a distance from the radiating transducer (20). The accumulated energy at the focal region induces tissue necrosis of the targeted lesion without causing damage to the surrounding vital structures (20). The ability of inducing immediate cell death at a distance from the ultrasound source without the need for surgery or insertion of ablation instruments makes HIFU an attractive treatment option for HCC (20).

In the present study, we found that ANT2 was upregulated in sorafenib-resistant HCC Huh7 cells (Huh7-R) and its overexpression promoted sorafenib resistance. ANT2 induced the formation of CIC phenotypes and promoted metastasis-associated traits in the Huh7 cells. Silencing of miR-137 upregulated ANT2 protein expression in the Huh7 cells. miR-137 was downregulated in the Huh7-R cells, compared with the Huh7 cells and its restoration reversed sorafenib resistance in the Huh7-R cells. Restoration of miR-137 inhibited formation of CIC traits and attenuated the abilities of migration and invasion in the Huh7-R cells. Moreover, we demonstrated that HIFU in unresectable HCC upregulated serum miR-137. Combining HIFU and sorafenib may be a wise option for advanced and unresectable HCC.

Materials and methods

Patients

Between November 2012 and October 2014, 13 patients with HCC were enrolled in this clinical study. Four patients were not included in the present study since they either had >4 HCC foci (n=2) or hepatic dysfunction (Child-Pugh class C, n=2). The present study was approved by the Ethics Committee of the First Peoples Hospital of Jining, and each patient signed an informed consent form at the time of enrollment.

Human HCC cell line

Huh7 cells were purchased from the Biochemistry and Cell Biology Institute of Shanghai, Chinese Academy of Sciences, within 3 months of the experiments. To obtain sorafenib-resistant Huh7 cells (Huh7-R cells), we treated Huh7 cells with increasing concentrations of sorafenib from 107 to 105 M. The established Huh7-R cells grew at a similar rate in the presence or absence of 105 M sorafenib for 3 days (data not shown). The IC50 (half maximal inhibitory concentration) of Huh7-R cells increased by 12-fold, compared with the Huh7 cells (data not shown). They were cultured in Dulbeccos modified Eagles medium (DMEM) supplemented with 10% fetal bovine serum and antibiotics (100 mg/ml penicillin, 100 U/ml streptomycin) in a 5% CO2 incubator at 37̊C.

Western blotting

Whole cell lysates were subjected to SDS-polyacrylamide gel electrophoresis and transferred to polyvinylidene difluoride membranes (Bio-Rad, Berkeley, CA, USA). Then, proteins were probed with primary antibodies against human ANT2 (1:500; ab195630), RASSF1 (1:500; ab180801), SIRT3 (1:500; ab217319), NURR1 (1:500; ab60149), DLX2 (1:500; ab30339), ADRB2 (1:500; EP795Y), CD133 (1:500; ab19898), CD44 (1:500; ab157107), EpCAM (1:500; ab71916) and β-actin (1:500; ab8227; all from Abcam, Cambridge, MA, USA) overnight at 4̊C. Secondary antibodies (1:10,000; ab150077; Abcam) were used for 30 min at room temperature. The specific proteins were visualized by Odyssey™ Infrared Imaging System (Gene Company, Lincoln, NE, USA). β-actin expression was used as an internal control to show equal loading of the protein samples.

MTT assay

The proliferation of cells was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay (Sigma-Aldrich, St Louis, MO, USA). The MTT analysis was performed as previously described (2126). In brief, the cells were plated in 96-well plates in DMEM containing 10% fetal bovine serum at a density of 8×103 cells/well at 37 °C in a 5% CO2 incubator for 12 h. Cells were transfected with ANT2-expressing plasmid or empty vectors and were then treated with sorafenib or dimethyl sulfoxide (DMSO) (10−4-102) for 24 h. Alternatively, cells were transfected with pre-miR-137 or control miR (mock) for 24 h. Then MTT solution (5 mg·ml−1) was added to the wells (20 µl/well). Subsequently the plates were incubated in a cell incubator for 4 h, then the supernatant was removed and 150 µl of DMSO was added to each well. After incubation for 10 min, the absorbance of each well was assessed using a Synergy™ 4 Hybrid microplate reader (BioTek Instruments, Winooski, VT, USA) at a wavelength of 570 nm, with the reference wavelength set at 630 nm. The absorbance was directly proportional to the number of cells that survived.

Sphere formation assay

Cells (103/ml) in serum-free RPMI-1640/1 mM Na-pyruvate were seeded on 0.5% agar precoated 6-well plates. After 10 days, half the medium was replaced with fresh medium every third day. Single spheres were selected and counted.

Real-time PCR for microRNAs (miRs)

Total RNA was extracted using the miRNeasy Mini kit and RNase-free DNase Set (Qiagen, Valencia, CA, USA) following the protocol provided by the manufacturer. The expression level of microRNA was analyzed using TaqMan MicroRNA Assay kit (Applied Biosystems) following the manufacturer's protocol.

Immunofluorescence staining

Immunofluorescence staining was performed as previously described (27). After transfection, the cells were fixed with 4% paraformaldehyde for 10 min and permeabilized with phosphate-buffered saline (PBS) containing 1% Triton X-100 for 10 min at room temperature. Then, the coverslips were blocked with BSA and incubated with the primary antibodies against ANT2 (Abcam) overnight. The following day, the cells were incubated with the secondary antibodies (Abcam).

Bioinformatics method

The analysis of potential microRNA target sites was performed with the commonly used prediction algorithm, miRanda (http://www.microrna.org/).

Migration and invasion assays

Migration and invasion assays were performed as previously described (28).

Wound healing assay

Cells were seeded onto 6-well plates. Monolayers of cells were wounded with yellow pipette tips (volume range, 200µl). After washing, the cells were incubated in fresh culture medium. The wounded areas were photographed at 0 and 36 h using a Nikon inverted microscope.

Anoikis assays

Anoikis resistance was evaluated by seeding 7×104 cells in ultralow attachment plates (Corning Inc., Corning, NY, USA). After 24 h of anchorage-independent culture, cells were transfected as indicated and resuspended in 0.4% trypan blue (Sigma-ALdrich) and the viability of the cells was assessed using the CellTiter-Glo® Luminescent Cell Viability Assay (Promega, Madison, WI, USA). The cells were harvested with Triton X-100 lysis buffer at indicated times.

Statistical analysis

Data are presented as the mean ± SEM. A Student's t-test (two-tailed) was used to compare differences between two groups (P<0.05 was considered significant).

Results

ANT2 is upregulated in sorafenib-resistant Huh7 cells (Huh7-R cells) and its overexpression promotes sorafenib resistance in sorafenib-sensitive Huh7 cells

In order to detect whether sorafenib resistance is associated with ANT2 protein expression, we analyzed the protein expression of ANT2 in Huh7 and Huh7-R cells. The results revealed that the ANT2 protein was upregulated in the Huh7-R cells (Fig. 1A). To identify the role of ANT2, we ascertained whether ANT2-expressing plasmids could cause stable expression of the ANT2 protein in the Huh7 cells. The results showed that the ANT2 protein was significantly increased by ANT2-expressing plasmids in the cells (Fig. 1B). To further determine whether ANT2 affects sorafenib efficacy in HCC cells, we transfected Huh7 cells with the ANT2-expressing plasmids. Then, we performed an MTT assay in the cells transfected with the ANT2-expressing plasmids. The results revealed that ANT2 transformed Huh7 to Huh7-R cells (Fig. 1C), suggesting that its overexpression promotes sorafenib resistance.

To identify whether ANT2 affects RASSF1, SIRT3, NURR1, DLX2 and ADRB2, we performed western blotting to detect their expression in Huh7 cells. Our results showed that RASSF1 was downregulated and NURR1, DLX2 and ADRB2 were upregulated in the Huh7 cells transfected with ANT2 (Fig. 1D).

ANT2 promotes formation of CIC phenotypes in Huh7 cells

In order to identify whether ANT2 affects CIC traits in Huh7 cells, we performed a sphere-forming assay to assess the ability of CIC or CIC-like cell-self renewal in Huh7 cells. The sphere-forming assay revealed that ANT2-overexpressing cells formed much bigger spheres after 14 days of culture when compared to the control cells, indicating markedly increased CIC traits by ANT2 (Fig. 2A). CD133, CD44 and EpCAM are positively associated with CIC-like characteristics in HCC (2931). To determine whether ANT2 regulates CD133, CD44 and EpCAM protein expression, we performed western blotting in Huh7 cells transfected with the ANT2-expressing plasmids and empty vectors. The results showed that the protein expression of CD133, CD44 and EpCAM was upregulated in the Huh7 cells transfected with the ANT2-expressing plasmids (Fig. 2B).

ANT2 promotes metastasis-associated traits in Huh7 cells

To determine whether cells with increased CIC characteristics have increased metastatic ability, we performed migration, invasion, wound healing and anoikis assays. We found that migration, invasion and anoikis resistance were increased by ANT2 (Fig. 3A-C).

Silencing of miR-137 upregulates ANT2 protein expression in Huh7 cells

Having demonstrated that ANT2 was upregulated in Huh7-R cells and that its overexpression promoted sorafenib resistance in Huh7 cells and promoted formation of CIC phenotypes, we next studied the mechanisms regulating ANT2 expression in Huh7 cells. miRs are a class of small non-coding RNAs (~22 nucleotides), that negatively regulate protein-coding gene expression by targeting mRNA degradation or translation inhibition (32,33).

To further confirm whether ANT2 could be regulated by microRNAs, we employed the commonly used prediction algorithm, miRanda (http://www.microrna.org/microrna/home.do) to analyze the 3 untranslated region (3′UTR) of ANT2. Twelve miRs were identified by the algorithm. However, our interests concerned miR-137, since it has been reported that miR-137 is significantly downregulated in HCC. Its decreased expression is associated with vascular invasion, incomplete involucrum and distant metastasis (28). Target sites on the 3′UTR of ANT2 are shown in Fig. 4A. We reasoned that miR-137 downregulated ANT2 expression by targeting its 3′UTR in HCC cells. Sliencing of miR-137 contributes to the upregulation of ANT2 and sorafenib resistance in Huh7 cells.

In an attempt to identify the role of miR-137 in the regulation of ANT2 expression in Huh7 cells, we transfected Huh7 cells with anti-miR-137 and scramble. After transfection, miR-137 expression was detected by real-time PCR and the results revealed that miR-137 was significantly decreased by anti-miR-137 in the cells (Fig. 4B). To ascertain the reason, we performed western blotting to detect ANT2 protein expression in Huh7 cells transfected with anti-miR-137 and scramble. The results revealed that the protein expression of ANT2 was significantly upregulated by anti-miR-137 (Fig. 4C). We next performed immunofluorescence analyses in Huh7 cells transfected with anti-miR-137 and scramble. The results showed that the protein expression of ANT2 was clearly increased in the cells transfected with anti-miR-137 (Fig. 4D).

miR-137 is downregulated and its restoration reverses sorafenib resistance in Huh7-R cells

In order to detect whether sorafenib resistance is associated with miR-137 expression, we analyzed miR-137 expression in Huh7 and Huh7-R cells. The results revealed that miR-137 expression was downregulated in the Huh7-R cells (Fig. 5A). To identify the role of miR-137, we determined whether pre-miR-137 could cause stable expression of miR-137 in Huh7-R cells. The results showed that the expression of miR-137 was significantly increased by pre-miR-137 in the cells (Fig. 5B). To further ascertain whether miR-137 affects sorafenib efficacy in HCC cells, we transfected Huh7-R cells with pre-miR-137. Then, we performed an MTT assay in Huh7-R cells transfected with pre-miR-137. The results revealed that miR-137 transformed Huh7-R to Huh7 cells (Fig. 5C), suggesting that its overexpression reversed sorafenib resistance. To identify whether miR-137 affects RASSF1, SIRT3, NURR1, DLX2 and ADRB2, we performed western blotting to detect their expression in Huh7-R cells. Our results showed that RASSF1 was upregulated and NURR1, DLX2 and ADRB2 were downregulated in the Huh7-R cells transfected with pre-miR-137 (Fig. 5D).

miR-137 inhibits formation of CIC phenotypes in Huh7-R cells

In order to identify whether miR-137 affects CIC traits in Huh7-R cells, we performed a sphere-forming assay to assess the ability of CIC or CIC-like cell self-renewal in Huh7-R cells. The sphere-forming assay revealed that miR-137-overexpressing cells formed much smaller spheres after 14 days of culture as compared with the control cells, indicating markedly increased CIC traits by miR-137 (Fig. 6A). To determine whether miR-137 regulates the protein expression of CD133, CD44 and EpCAM, we performed western blotting in Huh7-R cells transfected with pre-miR-137 and control miR. The results revealed that the protein expression of CD133, CD44 and EpCAM was downregulated in the Huh7-R cells transfected with pre-miR-137 (Fig. 6B).

miR-137 inhibits metastasis-associated traits in Huh7-R cells

To determine whether cells with decreased CIC characteristics had attenuated metastatic ability, we performed migration, invasion and anoikis assays. We found that migration, invasion and anoikis resistance were inhibited by pre-miR-137 in the Huh7-R cells (Fig. 7A and B). Moreover, in order to detect whether miR-137 affects proliferation, we performed an MTT assay in the Huh7-R cells. We found that its overexpression inhibited proliferation in the Huh7-R cells (Fig. 7C).

HIFU promotes serum miR-137 expression in unresectable HCC patients

In order to determine whether HIFU affects serum miR-137 expression in unresectable HCC patients, we recruited 9 unresectable HCC patients who received HIFU treatment. Real-time PCR was performed to compare the difference in serum miR-137 before and after treatment. We found that receiving HIFU significantly promoted miR-137 expression in the serum of these patients (Fig. 8).

Discussion

Sorafenib, a multikinase inhibitor, is the only standard clinical drug used against patients with advanced hepatocellular carcinoma (HCC). However, development of sorafenib resistance in HCC often prevents its long-term efficacy. Therefore, novel targets and strategies are urgently needed to improve the antitumor effect of sorafenib.

miR-137 expression is significantly downregulated in HCC. Its decreased expression is associated with vascular invasion, incomplete involucrum and distant metastasis (34). Decreased miR-137 expression is an independent indicator for poor survival (34). Overexpression of miR-137 suppresses cell proliferation, migration and invasion in vitro (34). Consistent with the previous studies, we demonstrated that decreased miR-137 expression is associated with sorafenib resistance in HCC Huh7 cells. Current treatment cannot eliminate cancer-initiating cells (CICs) (2,3). This is a cause for anticancer drug resistance and recurrence. We found that miR-137 inhibited formation of CIC traits as well as migration and invasion in Huh7-R cells. RASSF1 is a MAPK signaling factor and knockdown of RASSF1 increased sorafenib resistance (35). Knockdown of NURR1 significantly increased cell sensitivity to sorafenib and inhibited the cell growth, migration and invasion of HCC cells, both in vitro and in vivo (36). DLX2 facilitates sorafenib resistance by promoting the expression of markers of epithelial-mesenchymal transition and by activating the extracellular signal-regulated protein kinase pathway (37). ADRB2 signaling promotes HCC progression and sorafenib resistance by inhibiting autophagic degradation of HIF1α (38). We demonstrated that RASSF1 expression can be induced and NURR1, DLX2 and ADRB2 can be inhibited by miR-137. The results indicate that miR-137 may be a therapeutic target and a reliable biomarker that can be used to predict sorafenib resistance and ensure more effective clinical management.

ANT2 suppression by shRNA exerts anticancer effects in HCC by regulating different pathways (1719). However, its regulatory mechanism has yet to be reported. We found that silencing of miR-137 significantly upregulated ANT2 protein expression in Huh7 cells. Moreover, we demonstrated that ANT2 was upregulated in sorafenib-resistant HCC Huh7 cells (Huh7-R) and its overexpression promoted sorafenib resistance. ANT2 induced the formation of CIC phenotypes and promoted metastasis-associated traits in the Huh7 cells. We demonstrated that ANT2 overexpression inhibited RASSF1 expression and promoted NURR1, DLX2 and ADRB2 expression in Huh7 cells. In the present study, we discovered the role for ANT2 in HCC, its association with sorafenib resistance, and the antitumor effects of a newly identified microRNA, miR-137, that targets ANT2. These findings have potential therapeutic significance as testing for the absence of ANT2 at diagnosis may be helpful for identifying patients who are likely to have a response to sorafenib.

HIFU is the latest developed local ablation technique for unresectable HCC (20). We found that after receiving HIFU, miR-137 expression was upregulated in the serum of patients with unresectable HCC (Fig. 9). Thus, combining HIFU and sorafenib may be a wise option for advanced and unresectable HCC (Fig. 9).

References

1 

Cervello M, McCubrey JA, Cusimano A, Lampiasi N, Azzolina A and Montalto G: Targeted therapy for hepatocellular carcinoma: Novel agents on the horizon. Oncotarget. 3:236–260. 2012. View Article : Google Scholar : PubMed/NCBI

2 

Dean M, Fojo T and Bates S: Tumour stem cells and drug resistance. Nat Rev Cancer. 5:275–284. 2005. View Article : Google Scholar : PubMed/NCBI

3 

Zhang Q, Shi S, Yen Y, Brown J, Ta JQ and Le AD: A subpopulation of CD133+ cancer stem-like cells characterized in human oral squamous cell carcinoma confer resistance to chemotherapy. Cancer Lett. 289:151–160. 2010. View Article : Google Scholar : PubMed/NCBI

4 

Llovet JM, Ricci S, Mazzaferro V, Hilgard P, Gane E, Blanc JF, de Oliveira AC, Santoro A, Raoul JL, Forner A, et al: SHARP Investigators Study Group: Sorafenib in advanced hepatocellular carcinoma. N Engl J Med. 359:378–390. 2008. View Article : Google Scholar : PubMed/NCBI

5 

Di Maio M, Daniele B and Perrone F: Targeted therapies: Role of sorafenib in HCC patients with compromised liver function. Nat Rev Clin Oncol. 6:505–506. 2009. View Article : Google Scholar : PubMed/NCBI

6 

Bioulac-Sage P, Laumonier H, Couchy G, Le Bail B, Sa Cunha A, Rullier A, Laurent C, Blanc JF, Cubel G, Trillaud H, et al: Hepatocellular adenoma management and phenotypic classification: The Bordeaux experience. Hepatology. 50:481–489. 2009. View Article : Google Scholar : PubMed/NCBI

7 

Liu P, Cheng H, Roberts TM and Zhao JJ: Targeting the phosphoinositide 3-kinase pathway in cancer. Nat Rev Drug Discov. 8:627–644. 2009. View Article : Google Scholar : PubMed/NCBI

8 

Scanga A and Kowdley K: Sorafenib: A glimmer of hope for unresectable hepatocellular carcinoma? Hepatology. 49:332–334. 2009. View Article : Google Scholar : PubMed/NCBI

9 

Wilhelm SM, Carter C, Tang L, Wilkie D, McNabola A, Rong H, Chen C, Zhang X, Vincent P, McHugh M, et al: BAY 43–9006 exhibits broad spectrum oral antitumor activity and targets the RAF/MEK/ERK pathway and receptor tyrosine kinases involved in tumor progression and angiogenesis. Cancer Res. 64:7099–7109. 2004. View Article : Google Scholar : PubMed/NCBI

10 

Panka DJ, Wang W, Atkins MB and Mier JW: The Raf inhibitor BAY 43–9006 (Sorafenib) induces caspase-independent apoptosis in melanoma cells. Cancer Res. 66:1611–1619. 2006. View Article : Google Scholar : PubMed/NCBI

11 

Adnane L, Trail PA, Taylor I and Wilhelm SM: Sorafenib (BAY 43–9006, Nexavar), a dual-action inhibitor that targets RAF/MEK/ERK pathway in tumor cells and tyrosine kinases VEGFR/PDGFR in tumor vasculature. Methods Enzymol. 407:597–612. 2006. View Article : Google Scholar : PubMed/NCBI

12 

Wilhelm S, Carter C, Lynch M, Lowinger T, Dumas J, Smith RA, Schwartz B, Simantov R and Kelley S: Discovery and development of sorafenib: A multikinase inhibitor for treating cancer. Nat Rev Drug Discov. 5:835–844. 2006. View Article : Google Scholar : PubMed/NCBI

13 

Zhang W, Konopleva M, Shi YX, McQueen T, Harris D, Ling X, Estrov Z, Quintás-Cardama A, Small D, Cortes J, et al: Mutant FLT3: A direct target of sorafenib in acute myelogenous leukemia. J Natl Cancer Inst. 100:184–198. 2008. View Article : Google Scholar : PubMed/NCBI

14 

Cheng AL, Kang YK, Chen Z, Tsao CJ, Qin S, Kim JS, Luo R, Feng J, Ye S, Yang TS, et al: Efficacy and safety of sorafenib in patients in the Asia-Pacific region with advanced hepatocellular carcinoma: A phase III randomised, double-blind, placebo-controlled trial. Lancet Oncol. 10:25–34. 2009. View Article : Google Scholar : PubMed/NCBI

15 

Schönfeld P, Schild L and Bohnensack R: Expression of the ADP/ATP carrier and expansion of the mitochondrial (ATP + ADP) pool contribute to postnatal maturation of the rat heart. Eur J Biochem. 241:895–900. 1996. View Article : Google Scholar : PubMed/NCBI

16 

Chevrollier A, Loiseau D, Reynier P and Stepien G: Adenine nucleotide translocase 2 is a key mitochondrial protein in cancer metabolism. Biochim Biophys Acta. 1807:562–567. 2011. View Article : Google Scholar : PubMed/NCBI

17 

Jang JY, Jeon YK, Lee CE and Kim CW: ANT2 suppression by shRNA may be able to exert anticancer effects in HCC further by restoring SOCS1 expression. Int J Oncol. 42:574–582. 2013.PubMed/NCBI

18 

Baik SH, Lee J, Lee YS, Jang JY and Kim CW: ANT2 shRNA downregulates miR-19a and miR-96 through the PI3K/Akt pathway and suppresses tumor growth in hepatocellular carcinoma cells. Exp Mol Med. 48:e2222016. View Article : Google Scholar : PubMed/NCBI

19 

Jang JY, Lee YS, Jeon YK, Lee K, Jang JJ and Kim CW: ANT2 suppression by shRNA restores miR-636 expression, thereby downregulating Ras and inhibiting tumorigenesis of hepatocellular carcinoma. Exp Mol Med. 45:e32013. View Article : Google Scholar : PubMed/NCBI

20 

Ng KK, Poon RT, Chan SC, Chok KS, Cheung TT, Tung H, Chu F, Tso WK, Yu WC, Lo CM, et al: High-intensity focused ultrasound for hepatocellular carcinoma: A single-center experience. Ann Surg. 253:981–987. 2011. View Article : Google Scholar : PubMed/NCBI

21 

Liao XH, Li YQ, Wang N, Zheng L, Xing WJ, Zhao DW, Yan TB, Wang Y, Liu LY, Sun XG, et al: Re-expression and epigenetic modification of maspin induced apoptosis in MCF-7 cells mediated by myocardin. Cell Signal. 26:1335–1346. 2014. View Article : Google Scholar : PubMed/NCBI

22 

Liao XH, Wang Y, Wang N, Yan TB, Xing WJ, Zheng L, Zhao DW, Li YQ, Liu LY, Sun XG, et al: Human chorionic gonadotropin decreases human breast cancer cell proliferation and promotes differentiation. IUBMB Life. 66:352–360. 2014. View Article : Google Scholar : PubMed/NCBI

23 

Liao XH, Xiang Y, Yu CX, Li JP, Li H, Nie Q, Hu P, Zhou J and Zhang TC: STAT3 is required for MiR-17-5p-mediated sensitization to chemotherapy-induced apoptosis in breast cancer cells. Oncotarget. Feb 2–2017.(Epub ahead of print).

24 

Liao XH, Li JY, Dong XM, Wang X, Xiang Y, Li H, Yu CX, Li JP, Yuan BY, Zhou J, et al: ERα inhibited myocardin-induced differentiation in uterine fibroids. Exp Cell Res. 350:73–82. 2017. View Article : Google Scholar : PubMed/NCBI

25 

Liao XH, Lu DL, Wang N, Liu LY, Wang Y, Li YQ, Yan TB, Sun XG, Hu P and Zhang TC: Estrogen receptor α mediates proliferation of breast cancer MCF-7 cells via a p21/PCNA/E2F1-dependent pathway. FEBS J. 281:927–942. 2014. View Article : Google Scholar : PubMed/NCBI

26 

Xiang Y, Lu DL, Li JP, Yu CX, Zheng DL, Huang X, Wang ZY, Hu P, Liao XH and Zhang TC: Myocardin inhibits estrogen receptor alpha-mediated proliferation of human breast cancer MCF-7 cells via regulating MicroRNA expression. IUBMB Life. 68:477–487. 2016. View Article : Google Scholar : PubMed/NCBI

27 

Ren ZG, Dong SX, Han P and Qi J: miR-203 promotes proliferation, migration and invasion by degrading SIK1 in pancreatic cancer. Oncol Rep. 35:1365–1374. 2016.PubMed/NCBI

28 

Lu Y, Chopp M, Zheng X, Katakowski M, Buller B and Jiang F: MiR-145 reduces ADAM17 expression and inhibits in vitro migration and invasion of glioma cells. Oncol Rep. 29:67–72. 2013.PubMed/NCBI

29 

Suetsugu A, Nagaki M, Aoki H, Motohashi T, Kunisada T and Moriwaki H: Characterization of CD133+ hepatocellular carcinoma cells as cancer stem/progenitor cells. Biochem Biophys Res Commun. 351:820–824. 2006. View Article : Google Scholar : PubMed/NCBI

30 

Zhu Z, Hao X, Yan M, Yao M, Ge C, Gu J and Li J: Cancer stem/progenitor cells are highly enriched in CD133+CD44+ population in hepatocellular carcinoma. Int J Cancer. 126:2067–2078. 2010.PubMed/NCBI

31 

Yamashita T, Ji J, Budhu A, Forgues M, Yang W, Wang HY, Jia H, Ye Q, Qin LX, Wauthier E, et al: EpCAM-positive hepatocellular carcinoma cells are tumor-initiating cells with stem/progenitor cell features. Gastroenterology. 136:1012–1024. 2009. View Article : Google Scholar : PubMed/NCBI

32 

Lee RC, Feinbaum RL and Ambros V: The C. elegans heterochronic gene lin-4 encodes small RNAs with antisense complementarity to lin-14. Cell. 75:843–854. 1993. View Article : Google Scholar : PubMed/NCBI

33 

Pasquinelli AE, Reinhart BJ, Slack F, Martindale MQ, Kuroda MI, Maller B, Hayward DC, Ball EE, Degnan B, Müller P, et al: Conservation of the sequence and temporal expression of let-7 heterochronic regulatory RNA. Nature. 408:86–89. 2000. View Article : Google Scholar : PubMed/NCBI

34 

Liu LL, Lu SX, Li M, Li LZ, Fu J, Hu W, Yang YZ, Luo RZ, Zhang CZ and Yun JP: FoxD3-regulated microRNA-137 suppresses tumour growth and metastasis in human hepatocellular carcinoma by targeting AKT2. Oncotarget. 5:5113–5124. 2014. View Article : Google Scholar : PubMed/NCBI

35 

Azumi J, Tsubota T, Sakabe T and Shiota G: miR-181a induces sorafenib resistance of hepatocellular carcinoma cells through downregulation of RASSF1 expression. Cancer Sci. 107:1256–1262. 2016. View Article : Google Scholar : PubMed/NCBI

36 

Emma MR, Iovanna JL, Bachvarov D, Puleio R, Loria GR, Augello G, Candido S, Libra M, Gulino A, Cancila V, et al: NUPR1, a new target in liver cancer: Implication in controlling cell growth, migration, invasion and sorafenib resistance. Cell Death Dis. 7:e22692016. View Article : Google Scholar : PubMed/NCBI

37 

Liu J, Cui X, Qu L, Hua L, Wu M, Shen Z, Lu C and Ni R: Overexpression of DLX2 is associated with poor prognosis and sorafenib resistance in hepatocellular carcinoma. Exp Mol Pathol. 101:58–65. 2016. View Article : Google Scholar : PubMed/NCBI

38 

Wu FQ, Fang T, Yu LX, Lv GS, Lv HW, Liang D, Li T, Wang CZ, Tan YX, Ding J, et al: ADRB2 signaling promotes HCC progression and sorafenib resistance by inhibiting autophagic degradation of HIF1α. J Hepatol. 65:314–324. 2016. View Article : Google Scholar : PubMed/NCBI

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April-2017
Volume 37 Issue 4

Print ISSN: 1021-335X
Online ISSN:1791-2431

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Spandidos Publications style
Lu A, Lv B, Qiu F, Wang X and Cao X: Upregulation of miR-137 reverses sorafenib resistance and cancer-initiating cell phenotypes by degrading ANT2 in hepatocellular carcinoma. Oncol Rep 37: 2071-2078, 2017.
APA
Lu, A., Lv, B., Qiu, F., Wang, X., & Cao, X. (2017). Upregulation of miR-137 reverses sorafenib resistance and cancer-initiating cell phenotypes by degrading ANT2 in hepatocellular carcinoma. Oncology Reports, 37, 2071-2078. https://doi.org/10.3892/or.2017.5498
MLA
Lu, A., Lv, B., Qiu, F., Wang, X., Cao, X."Upregulation of miR-137 reverses sorafenib resistance and cancer-initiating cell phenotypes by degrading ANT2 in hepatocellular carcinoma". Oncology Reports 37.4 (2017): 2071-2078.
Chicago
Lu, A., Lv, B., Qiu, F., Wang, X., Cao, X."Upregulation of miR-137 reverses sorafenib resistance and cancer-initiating cell phenotypes by degrading ANT2 in hepatocellular carcinoma". Oncology Reports 37, no. 4 (2017): 2071-2078. https://doi.org/10.3892/or.2017.5498