GSE110059
BS008, an amiloride derivative, can regulate the alternative splicing of multiple gene transcripts in cancer cells
Alternative splicing (AS) is a process that enables a mRNA to generate different protein isoforms that may have different biological functions or properties. Cancer cells often use this maneuverability to produce proteins that contribute to growth and survival. In previous study, we found that the antihypertensive drug amiloride has a novel biological function that regulates the AS on human cancer cells. However, it also showed that the effective concentration of amiloride in cancer treatment is too high to limit its use in future therapeutic application. In this study, we therefore used computational algorithms to predict the potential amiloride derivatives and found that BS008 is the most promising compound in all derivatives. The results demonstrated that BS008 can modulate the AS of apoptotic gene transcripts, including HIPK3, SMAC, and BCLX in cancer cells. Splicing regulatory involved a variety of histone modifications and splicing factors, and accompanied the changed of phosphorylation state of SR proteins during the splicing process. Inhibition of protein phosphatase-1 with okadaic acid pretreatment partially alleviated the effects of BS008 on the AS of HIPK3 and SMAC transcripts, as well as on the phosphorylation levels of SRSF3. RNA sequencing further discovered that the AS of many other apoptosis-related gene transcripts such as AATF, ATM, AIFM1, NFKB1, and API5 was modulated by BS008. We extended the study to apoptosis-associated molecules, and detected decreased levels of BCLX and increased levels of BAX and active CASPASE-3 in BS008-induced apoptosis. In vivo experiments indicated that the treatment of tumor-bearing mice with BS008 resulted in a marked decrease in tumor size. The combination BS008/sorafenib enhances anti-tumor activity of sorafenib and allows dose reduction of sorafenib without compromising its anti-tumor activity. In conclusion, these findings suggested that BS008, an amiloride derivative, may provide therapeutic potential for cancer treatment in future. Overall design: Examination of the global genes with altered alternative splicing in BS008-treated Huh-7 cells.