ARID1A Inactivation Increases Expression of circ0008399 and Promotes Cisplatin Resistance in Bladder Cancer

Objective Cisplatin(CDDP)-based chemotherapy is a first-line,drug regimen for muscle-invasive bladder cancer(BC)and metastatic bladder cancer.Clinically,resistance to CDDP restricts the clinical benefit of some bladder cancer patients.AT-rich interaction domain 1A(ARID1A)gene mutation occurs frequently in bladder cancer;however,the role of CDDP sensitivity in BC has not been studied.Methods We established ARID1A knockout BC cell lines using CRISPR/Cas9 technology.IC50 determination,flow cytometry analysis of apoptosis,and tumor xenograft assays were performed to verify changes in the CDDP sensitivity of BC cells losing ARID1A.qRT-PCR,Western blotting,RNA interference,bioinformatic analysis,and ChIP-qPCR analysis were performed to further explore the potential mechanism of ARID1A inactivation in CDDP sensitivity in BC.Results It was found that ARID1A inactivation was associated with CDDP resistance in BC cells.Mechanically,loss of ARID1A promoted the expression of eukaryotic translation initiation factor 4A3(EIF4A3)through epigenetic regulation.Increased expression of EIF4A3 promoted the expression of hsa_circ_0008399(circ0008399),a novel circular RNA(circRNA)identified in our previous study,which,to some extent,showed that ARID1A deletion caused CDDP resistance through the inhibitory effect of circ0008399 on the apoptosis of BC cells.Importantly,EIF4A3-IN-2 specifically inhibited the activity of EIF4A3 to reduce circ0008399 production and restored the sensitivity of ARID1A inactivated BC cells to CDDP.Conclusion Our research deepens the understanding of the mechanisms of CDDP resistance in BC and elucidates a potential strategy to improve the efficacy of CDDP in BC patients with ARID1A deletion through combination therapy targeting EIF4A3.

Erratum to:ARID1A Inactivation Increases Expression of circ0008399 and Promotes Cisplatin Resistance in Bladder Cancer

The original version of this article was revised due to production error by the vendor.The author“Hua-min DING”is one of the co-authors,and the name should be labeled correctly as appears on PDF.The affiliation of“Yu-jun SHUAI”and“Chao HUANG”is“Department of Urology,Union Hospital,Tongji Medical College,Huazhong University of Science and Technology,Wuhan 430022,China”,and both of them should be labeled as 1,as correctively appears on PDF.

Stable knockdown of heparanase expression in gastric cancer cells in vitro

AIM:To develop short hairpin RNA(shRNA)against heparanase,and to determine its effects on heparanase expression and the malignant characteristics of gastric cancer cells. METHODS:Heparanase-specific shRNA was constructed and transferred into cultured the gastric cancer cell line SGC-7901.Stable subclonal cells were screened by G418 selection.Heparanase expression was measured by reverse transcriptase-polymerase chain reaction(RT-PCR),real-time quantitative PCR and Western blotting.Cell proliferation was detected by 2-(4,5-dimethyltriazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT)colorimetry and colony formation assay. The in vitro invasiveness and metastasis of cancer cells were measured by cell adhesion assay,wound healingassay and matrigel invasion assay.The angiogenesis capabilities of cancer cells were measured by tube formation of endothelial cells. RESULTS:Stable transfection of heparanase-specific shRNA,but not of scrambled shRNA and mock vector,resulted in reduced mRNA and protein levels of heparanase.The shRNA-mediated knockdown of heparanase did not affect the cellular proliferation of SGC-7901 cells.However,the in vitro invasiveness and metastasis of cancer cells were decreased after knockdown of heparanase.Moreover,transfection of heparanase-specific shRNA decreased the in vitro angiogenesis capabilities of SGC-7901 cells. CONCLUSION:Stable knockdown of heparanase can efficiently decrease the invasiveness,metastasis and angiogenesis of human gastric cancer cells.In contrast,stable knockdown of heparanase does not affect the cell proliferation.