Li Jun, Jiang Donggen, Zhang Qian, Peng Shubin, Liao Guolong, Yang Xiangwei, Tang Jiani, Xiong Haiyun, Pang Jun
Department of Urology, Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, People's Republic of China.
Department of Rehabilitation Medicine, Seventh Affiliated Hospital, Sun Yat-sen University, Shenzhen 518107, People's Republic of China.
Cancer Manag Res. 2020 Jun 10;12:4309-4320. doi: 10.2147/CMAR.S253533. eCollection 2020.
Renal cell carcinoma (RCC) displays an increasing incidence and mortality rate worldwide in recent years. More and more evidence demonstrated microRNAs function as positive or negative regulatory factors in many cancers, while the role of miR-301a in RCC is still unclear.
The expression and clinical significance of miR-301a were assessed via bioinformatic software on open microarray datasets of the Cancer Genome Atlas (TCGA) and then confirmed by quantitative real-time PCR (qRT-PCR) in RCC cell lines. Loss of function assays were performed in RCC cell lines both in vitro and in vivo. Cell Counting Kit-8 (CCK-8), flow cytometry, luciferase reporter assays, Western blotting, and immunohistochemistry were employed to explore the mechanisms of the effect of miR-301a on RCC.
By analyzing RCC clinical specimens and cell lines, we found a uniform increased miR-301a in expression in comparison with normal renal tissue or normal human proximal tubule epithelial cell line (HK-2). In addition, miR-301a upregulation correlated advanced stage and poor prognosis of clear cell RCC (ccRCC). Anti-miR-301a could inhibit growth and cell cycle G1/S transition in RCC cell lines. Moreover, we found that PTEN was identified as a direct target of miR-301a that might partially interrupt miR-301a-induced G1/S transition. Importantly, nude-mouse models revealed that knockdown of miR-301a delayed tumor growth.
These results indicate that miR-301a functions as a tumor-promoting miRNA through regulating PTEN expression, representing a novel therapeutic target for RCC.
近年来，肾细胞癌（RCC）在全球范围内的发病率和死亡率呈上升趋势。越来越多的证据表明，微小RNA在许多癌症中作为正调控或负调控因子发挥作用，而miR-301a在RCC中的作用仍不清楚。
通过生物信息学软件在癌症基因组图谱（TCGA）的开放微阵列数据集上评估miR-301a的表达及其临床意义，然后通过定量实时PCR（qRT-PCR）在RCC细胞系中进行验证。在RCC细胞系中进行体内外功能缺失实验。采用细胞计数试剂盒-8（CCK-8）、流式细胞术、荧光素酶报告基因检测、蛋白质免疫印迹法和免疫组织化学法来探讨miR-301a对RCC影响的机制。
通过分析RCC临床标本和细胞系，我们发现与正常肾组织或正常人近端肾小管上皮细胞系（HK-2）相比，miR-301a的表达一致升高。此外，miR-301a的上调与透明细胞肾细胞癌（ccRCC）的晚期和不良预后相关。抗miR-301a可抑制RCC细胞系的生长和细胞周期G1/S期转换。此外，我们发现PTEN被确定为miR-301a的直接靶点，它可能部分阻断miR-301a诱导的G1/S期转换。重要的是，裸鼠模型显示敲低miR-301a可延缓肿瘤生长。
这些结果表明miR-301a通过调节PTEN表达发挥促癌微小RNA的作用，是RCC的一个新的治疗靶点。
