Second Department of Thoracic Surgery, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Department of Oncology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi, P.R. China.
Oncol Rep. 2017 Aug;38(2):1190-1198. doi: 10.3892/or.2017.5755. Epub 2017 Jun 27.
miR-367 is one of the most abundant miRNAs in human embryonic stem cells (hESCs) and is mainly involved in maintaining the pluripotency of stem cells. However, its role in cancer development remains poorly understood. In the present study, we explored the function and mechanism of the endogenous miR-367 in non-small cell lung cancer (NSCLC). In the present study, we demonstrated that the level of miR-367 in NSCLC was significantly higher than that in adjacent normal tissues, and its upregulation was positively correlated with tumor size, tumor differentiation and tumor-node-metastasis (TNM) stage. miR-367 was an indicator of a poorer prognosis in NSCLC patients. Furthermore, overexpression of miR-367 significantly inhibited apoptosis and enhanced proliferation by promoting cell cycle transition from G1 to S phase. In contrast, knockdown of miR-367 markedly reversed the cellular events observed with miR-367 overexpression. Moreover, we identified that F-box and WD repeat domain-containing 7 (FBXW7) is a novel target of miR-367. It reverses the oncogenic effects of miR-367 by downregulating its substrates, c-Myc and c-Jun, in NSCLC cells. Finally, studies in vivo revealed that knockdown of miR-367 inhibited the growth of xenografts in the nude mice by increasing the expression of FBXW7. In summary, our findings indicate that miR-367 exerts tumor-promoting effect by negatively regulating FBXW7 in NSCLC, and it could become a potential therapeutic target for NSCLC intervention.
miR-367 是人类胚胎干细胞(hESCs)中最丰富的 miRNA 之一,主要参与维持干细胞的多能性。然而,其在癌症发展中的作用仍知之甚少。在本研究中,我们探讨了内源性 miR-367 在非小细胞肺癌(NSCLC)中的功能和机制。本研究表明,miR-367 在 NSCLC 中的水平明显高于相邻正常组织,其上调与肿瘤大小、肿瘤分化和肿瘤-淋巴结-转移(TNM)分期呈正相关。miR-367 是 NSCLC 患者预后不良的指标。此外,miR-367 的过表达通过促进细胞周期从 G1 期向 S 期的转变,显著抑制细胞凋亡并增强增殖。相比之下,miR-367 的敲低显著逆转了 miR-367 过表达所观察到的细胞事件。此外,我们鉴定出 F-box 和 WD 重复域蛋白 7(FBXW7)是 miR-367 的一个新靶点。它通过下调其底物 c-Myc 和 c-Jun,在 NSCLC 细胞中逆转 miR-367 的致癌作用。最后,体内研究表明,miR-367 的敲低通过增加 FBXW7 的表达抑制了裸鼠异种移植瘤的生长。总之,我们的研究结果表明,miR-367 通过负调控 NSCLC 中的 FBXW7 发挥促肿瘤作用,它可能成为 NSCLC 干预的潜在治疗靶点。