背景:环状RNA(circularRNAs,circRNAs)参与结直肠癌(CRC)进展和化学耐受性的调节。这里,我们试图揭示circ_0000395在CRC化学持久性中的功能和机制。
方法:circ_0000395,microRNA(miR)-153-5p,通过定量实时PCR测定肌球蛋白VI(MYO6)。细胞生长,转移和奥沙利铂耐药性通过EdU分析进行评估,集落形成试验,流式细胞术,transwell分析,和细胞计数试剂盒8测定。采用异种移植瘤模型评估circ_0000395对CRC肿瘤生长和奥沙利铂敏感性的作用。通过蛋白质印迹分析耐药标志物和MYO6的蛋白表达。miR-153-5p与circ_0000395或MYO6之间的靶关系通过双荧光素酶报告基因测定和RIP测定进行验证。
结果:Circ_0000395在CRC组织和细胞中的表达增强。沉默circ_0000395抑制CRC细胞增殖,移民和入侵,同时促进细胞凋亡和奥沙利铂敏感性。此外,circ_0000395敲除还降低了CRC肿瘤的生长并增强了肿瘤对奥沙利铂的敏感性。此外,circ_0000395充当miR-153-5p的海绵,和miR-153-5p靶向MYO6。功能实验提示miR-153-5p抑制剂或MYO6过表达可以逆转circ_0000395敲低对CRC细胞生长的抑制作用,转移和奥沙利铂耐药。
结论:Circ_0000395促进CRC细胞生长,通过miR-153-5p/MYO6轴的转移和奥沙利铂耐药,这可能为CRC的治疗提供新的见解。
BACKGROUND: Circular RNAs (circRNAs) are involved in the regulation of colorectal cancer (CRC) progression and chemoresistence. Here, we attempted to reveal the function and mechanism of circ_0000395 in CRC chemoresistence.
METHODS: The expression levels of circ_0000395, microRNA (miR)-153-5p, and myosin VI (
MYO6) were determined by quantitative real-time PCR. Cell growth, metastasis and oxaliplatin resistance were evaluated via EdU assay, colony formation assay, flow cytometry, transwell assay, and cell counting kit 8 assay. Xenograft tumor model was adopted to evaluate the role of circ_0000395 on CRC tumor growth and oxaliplatin sensitivity. Protein expression of drug-resistance markers and
MYO6 was analyzed by western blot. The target relationship between miR-153-5p and circ_0000395 or
MYO6 was validated via dual-luciferase reporter assay and RIP assay.
RESULTS: Circ_0000395 expression was enhanced in CRC tissues and cells. Silencing of circ_0000395 repressed CRC cell proliferation, migration and invasion, while promoted apoptosis and oxaliplatin sensitivity. Besides, circ_0000395 knockdown also reduced CRC tumor growth and enhanced the sensitivity of tumor to oxaliplatin. Additionally, circ_0000395 acted as a sponge for miR-153-5p, and miR-153-5p targeted
MYO6. Functional experiments suggested that miR-153-5p inhibitor or MYO6 overexpression could reverse the suppressive effect of circ_0000395 knockdown on CRC cell growth, metastasis and oxaliplatin resistance.
CONCLUSIONS: Circ_0000395 promoted CRC cell growth, metastasis and oxaliplatin resistance via the miR-153-5p/
MYO6 axis, which might provide new insights into the treatment of CRC.