Background: MicroRNAs (miRNAs) have been extensively studied over the decades and have been identified as potential molecular targets for cancer therapy. To date, many miRNAs have been found participating in the tumorigenesis of non-small cell lung cancer (NSCLC). The present study was designed to evaluate the functions of miR-125b-1-3p in NSCLC cells.
Methods: MiR-125b-1-3p expression was detected in tissue samples from 21 NSCLC patients and in NSCLC cell lines using the real-time polymerase chain reaction. A549 cell lines were transfected with a miR-125b-1-3p mimic or miR-125b-1-3p antisense. Cell counting kit-8, wound healing, Matrigel invasion assays, and flow cytometry were used to assess the effects of these transfections on cell growth, migration, invasion, and apoptosis, respectively. Western blotting was used to detect apoptosis-related proteins, expression of S1PR1, and the phosphorylation status of STAT3. Significant differences between groups were estimated using Student's t-test or a one-way analysis of variance.
Results: MiR-125b-1-3p was downregulated in NSCLC samples and cell lines. Overexpression of miR-125b-1-3p inhibited NSCLC cell proliferation (37.8 ± 9.1%, t = 3.191, P = 0.013), migration (42.3 ± 6.7%, t = 6.321, P = 0.003), and invasion (57.6 ± 11.3%, t = 4.112, P = 0.001) and simultaneously induced more NSCLC cell apoptosis (2.76 ± 0.78 folds, t = 3.772, P = 0.001). MiR-125b-1-3p antisense resulted in completely opposite results. S1PR1 was found as the target gene of miR-125b-1-3p. Overexpression of miR-125b-1-3p inhibited S1PR1 protein expression (27.4 ± 6.1% of control, t = 4.083, P = 0.007). In addition, S1PR1 siRNA decreased STAT3 phosphorylation (16.4 ± 0.14% of control, t = 3.023, P = 0.015), as in cells overexpressing miR-125b-1-3p (16.7 ± 0.17% of control, t = 4.162, P = 0.026).
Conclusion: Our results suggest that miR-125b-1-3p exerts antitumor functions in NSCLC cells by targeting S1PR1.
miR-125-1-3p通过抑制S1PR1基因抑制非小细胞肺癌细胞摘要背景：微小RNA作为潜在的肿瘤治疗靶点目标，近年来引起了诸多研究者的关注。迄今为止，有诸多miRNA被发现在非小细胞肺癌(NSCLC)中起到重要作用。本次研究目的探索miR-125-1-3p在NSCLC中的作用及功能。 方法：MiR-125b-1-3p在21个NSCLC患者组织以及NSCLC细胞系中的表达水平采用RT-PCR进行检测。利用miR-125b-1-3p mimic 或者 miR-125b-1-3p antisense转染NSCLC A549细胞系用来过表达或沉默miR-125b-1-3p。CCK-8, 划痕实验，侵袭实验以及流式细胞分别用来检测miR-125b-1-3p对细胞增殖，迁移，侵入以及凋亡的影响。Western blotting用来检测凋亡相关蛋白，S1PR1蛋白以及STAT3蛋白的磷酸化状态。 结果：MiR-125b-1-3p在NSCLC组织以及细胞系中表达下调。过表达miR-125b-1-3p后可以抑制NSCLC细胞的增殖 (37.8 ± 9.1%, t = 3.191, P = 0.013)，迁移 (42.3 ± 6.7%, t = 6.321, P = 0.003) 以及侵袭 (57.6 ± 11.3%, t = 4.112, P = 0.001)。与此同时，过表达miR-125b-1-3p可以同时诱导NSCLC细胞凋亡 (2.76 ± 0.78 fold, t = 3.772, P = 0.001)。抑制miR-125b-1-3p则取得相反的表型结果。S1PR1被发现是miR-125b-1-3p的调控基因。过表达miR-125b-1-3p能够抑制S1PR1蛋白的表达 (27.4 ± 6.1% of control, t = 4.083, P = 0.007)。此外过表达miR-125b-1-3p (16.7 ± 0.17% of control, t = 4.162, P = 0.026) 以及沉默S1PR1蛋白 (16.4 ± 0.14% of control, t = 3.023, P = 0.015) 后能够抑制STAT3蛋白的磷酸化。 结论：我们的发现揭示了miR-125b-1-3能够通过抑制S1PR1，从而在NSCLC中起到抑癌基因的作用。.
Keywords: Apoptosis; Non-Small Cell Lung Cancer; S1PR1; STAT3; miR-125b-1-3p.