Department of Medical Biotechnology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Department of Clinical Biochemistry, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Cell Biol Int. 2021 May;45(5):1001-1014. doi: 10.1002/cbin.11543. Epub 2021 Jan 13.
Signal transducer and activator of transcription 3 (STAT3) is a critical regulator for angiogenesis, cell cycle progression, apoptosis, and drug resistance. Resistance toward EGF receptor (EGFR) inhibitors is a significant clinical concern for metastatic colon cancer patients. The present study aimed to evaluate the blocking influences of STAT3 decoy oligodeoxynucleotides (ODNs) on the STAT3 survival signaling pathway in nonresistant and erlotinib-resistant SW480 colon cancer cells. First, STAT3 decoy and scramble ODNs were designed according to STAT3 elements in the promoter region of MYCT1 gene and tested for the interaction of STAT3 protein with designed ODNs via in silico molecular docking study. Then, the efficiency of transfection and subcellular localization of ODNs were assessed using flow cytometry and fluorescence microscopy, respectively. Cell viability, cell cycle, and apoptosis tests, scratch and colony formation assays, and real-time PCR were also used to study the cancerous properties of cells. A considerable decrease in proliferation of colon cancer cells was observed with blockade of STAT3 signaling due to cell cycle arrest and induced apoptosis via downregulation of cyclin D1 and Bcl-XL, respectively. Furthermore, upon transfecting STAT3 decoy ODNs, colony formation potential and migration activity in both SW480 colon cancer cell lines were decreased compared to the control groups. From this study, it could be concluded that STAT3 is critical for cell growth inhibition and metastatic properties reduction of resistant SW480 colon cancer cells; therefore, STAT3 decoy ODNs could be considered as potential therapeutics along with current remedies for treating drug-resistant colon cancer.
信号转导子和转录激活子 3（STAT3）是血管生成、细胞周期进程、细胞凋亡和耐药性的关键调节因子。表皮生长因子受体（EGFR）抑制剂的耐药性是转移性结肠癌患者的一个重大临床问题。本研究旨在评估 STAT3 诱饵寡脱氧核苷酸（ODN）对非耐药和厄洛替尼耐药 SW480 结肠癌细胞中 STAT3 生存信号通路的阻断作用。首先，根据 MYCT1 基因启动子区域的 STAT3 元件设计了 STAT3 诱饵和随机 ODN，并通过计算机分子对接研究测试了 STAT3 蛋白与设计的 ODN 的相互作用。然后，分别通过流式细胞术和荧光显微镜评估 ODN 的转染效率和亚细胞定位。还使用细胞活力、细胞周期和细胞凋亡试验、划痕和集落形成试验以及实时 PCR 来研究细胞的癌变特性。阻断 STAT3 信号导致细胞周期停滞并通过下调细胞周期蛋白 D1 和 Bcl-XL 分别诱导细胞凋亡，从而观察到结肠癌细胞增殖显著减少。此外，与对照组相比，转染 STAT3 诱饵 ODN 后，两种 SW480 结肠癌细胞系的集落形成潜力和迁移活性均降低。从这项研究可以得出结论，STAT3 对于抑制耐药 SW480 结肠癌细胞的生长和降低其转移特性至关重要；因此，STAT3 诱饵 ODN 可以与当前的治疗方法一起被视为治疗耐药性结肠癌的潜在治疗方法。
