ARK5 promotes doxorubicin resistance in hepatocellular carcinoma via epithelial-mesenchymal transition.

AMP-activated protein kinase family member 5 (ARK5) overexpression has been reported in many human cancers, and ARK5 is associated with poor prognosis in hepatocellular carcinoma (HCC). However, whether ARK5 is involved in HCC chemoresistance is unclear. The present study aimed to investigate the role of ARK5 in HCC chemoresistance and the underlying mechanism. In this study, we found that SNU387 and SNU449 HCC cell lines overexpressing ARK5 displayed low doxorubicin sensitivity compared to Huh7 and Hep3B HCC cell lines with ARK5 low-expression. And knockdown of ARK5 increased the doxorubicin sensitivity in all HCC cell lines in the manner of inhibiting cell proliferation. Western blotting and immunofluorescence both showed that ARK5 knockdown upregulated E-cadherin and downregulated vimentin, which was consistent with the knockdown of TWIST, indicating ARK5 was involved in epithelial-mesenchymal transition (EMT). Moreover, suppressing ARK5 by siRNA restored E-cadherin and vimentin expression induced by doxorubicin treatment or hypoxia culture. Our results indicated ARK5 confers doxorubicin resistance in HCC via inducing EMT.

Xu T ，Zhang J ，Chen W ，Pan S ，Zhi X ，Wen L ，Zhou Y ，Chen BW ，Qiu J ，Zhang Y ，Yang Q ，Feng X ，Bai X ，Liang T ... -  《-》

FBW7 increases chemosensitivity in hepatocellular carcinoma cells through suppression of epithelial-mesenchymal transition.

Yu J ，Zhang W ，Gao F ，Liu YX ，Chen ZY ，Cheng LY ，Xie SF ，Zheng SS ... -  《-》

NSC 74859 enhances doxorubicin cytotoxicity via inhibition of epithelial-mesenchymal transition in hepatocellular carcinoma cells.

Doxorubicin-based therapy is not effective for the treatment of hepatocellular carcinomas (HCCs), which often undergo epithelial-mesenchymal transition (EMT) during tumor progression. Activation of signal transducer and activator of transcription 3 (STAT3) is associated with chemosensitivity and may contribute to EMT during HCC chemotherapy. Low doses of NSC 78459 (a novel STAT3 inhibitor) have little effect on HCC cell proliferation, but efficiently inhibit STAT3. HuH-7, Hep3B, and HepG2 cells, with epithelial phenotypes, show significantly enhanced doxorubicin cytotoxicity following co-treatment with NSC 74859, whereas mesenchymal SNU-449 cells show no such enhancement. NSC 74859 inhibits STAT3 activity and suppressed doxorubicin-induced EMT in epithelial HCC cells. siRNA-mediated STAT3 knockdown resulted in EMT inhibition, which led to attenuation of NSC 74859-mediated chemosensitivity. Our data indicate NSC 74859 co-administration enhances doxorubicin cytotoxicity by inhibiting STAT3 in epithelial HCC cells. STAT3 deactivation and associated EMT attenuation contribute to the synergistic anti-tumor effects of combined NSC 74859/doxorubicin therapy.

Hu QD ，Chen W ，Yan TL ，Ma T ，Chen CL ，Liang C ，Zhang Q ，Xia XF ，Liu H ，Zhi X ，Zheng XX ，Bai XL ，Yu XZ ，Liang TB ... -  《-》

Overexpression of the long non-coding RNA SPRY4-IT1 promotes tumor cell proliferation and invasion by activating EZH2 in hepatocellular carcinoma.

Increasing evidences have demonstrated that the dysregulation of long non-coding RNAs (lncRNAs) may act as an important role in tumor progression. The long non-coding RNA SPRY4 intronic transcript 1 (SPRY4-IT1) has been reported in some cancer including regulating cell growth, differentiation, apoptosis, and cancer progression. However, the expression and function of SPRY4-IT1 in the progression of hepatocellular carcinoma (HCC) remain largely unknown. The lncRNA SPRY4-IT1 was detected by quantitative real time PCR (qRT-PCR) in HCC cell lines, CCK8 cell proliferation and transwell invasion assays were performed to detect the GC cell proliferation and invasion abilities. The protein expression of E-cadherin, Vimentin and Twist1 was analyzed by Western blotting assays. Furthermore, RNA immunoprecipitation (RIP) and Chromatin immunoprecipitation (ChIP) assays were used to analyze potential molecular mechanism of SPRY4-IT1 in HCC cells. We found that SPRY4-IT1 was up-regulated in HCC cell lines. Further function analysis demonstrated that knockdown of SPRY4-IT1 significantly inhibited HCC cells proliferation and invasion, but over-expression of SPRY4-IT1 had the opposite effects on HCC cells in vitro. Moreover, our results also indicated that SPRY4-IT1 over-expression significantly promoted the epithelial-mesenchymal transition (EMT) by up-regulating the transcription factor Twist1 and EMT marker Vimentin and inhibited the E-cadherin expression in MHCC97L cell. Whereas, knockdown of SPRY4-IT1 suppressed the transcription factor Twist1 and EMT marker Vimentin and increased the E-cadherin expression in MHCC97H cells. Mechanisms investigations showed that SPRY4-IT1 interacted with the EZH2 and epigenetically repressed the E-cadherin expression. In vivo, we also demonstrated that the tumor growth was inhibited in SPRY4-IT1 knockdown group compared with the control group. These results suggested that lncRNA SPRY4-IT1 might be considered as a therapeutic target in HCC.

Zhou M ，Zhang XY ，Yu X 《-》

Doxorubicin-induced epithelial-mesenchymal transition through SEMA 4A in hepatocellular carcinoma.

Semaphorins are essential for the functions in the regulation of cell migration. SEMA 4A has been proven to play a prominent role in immune function and angiogenesis. However, whether SEMA 4A is involved in HCC chemoresistance is unclear. We investigated the role of SEMA 4A in HCC chemoresistance and the underlying mechanisms. We tested the doxorubicin sensitivity of the Huh7, and Hep-G2 HCC cell lines. Immunofluorescence and Western blot were used to detect the location and expression of EMT-related protein, such as, E-cadherin, Vimentin, and SEMA4A expression. Microarray data showed that SEMA 4A and SEMA 3F increased most dramatically under DOX treatment. Kncokdown of SEMA 4A in hepatoma cells can reduce EMT process. Expectedly, depletion of SEMA 4A also reversed EMT and increased the DOX sensitivity. SEMA 4A confers doxorubicin resistance on HCC by inducing epithelial-mesenchymal transition (EMT).

Pan JX ，Wang F ，Ye LY 《-》