Zhong Bing, Qin Zhiqiang, Zhou Hui, Yang Fengming, Wei Ke, Jiang Xi, Jia Ruipeng
Department of Urology, Nanjing First Hospital, Nanjing Medical University, Nanjing, China.
Department of Urology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, Huai'an, China.
J Cell Physiol. 2019 Sep;234(9):15025-15034. doi: 10.1002/jcp.28142. Epub 2019 Jan 15.
microRNAs have been recognized to regulate a wide range of biology of renal cell carcinoma (RCC). Although miR-505 has been reported to play as a suppressor in several human tumors, the physiological function of miR-505 in RCC still remain unknown. Therefore, the role of miR-505 and relevant regulatory mechanisms were investigated in RCC in this study. Quantitative real-time polymerase chain reaction was conducted to detect the expression of miR-505 and high mobility group box 1 (HMGB1) in both RCC tissues and cell lines. Immunohistochemical staining was used to assess the correlation between HMGB1 expression and PCNA expression in RCC tissues. Subsequently, the effects of miR-505 on proliferation were determined in vitro using cell counting kit-8 proliferation assays and 5-ethynyl-2'-deoxyuridine incorporation. The molecular mechanism underlying the relevance between miR-505 and HMGB1 was confirmed by luciferase assay. Xenograft tumor formation was used to reflect the proliferative capacity of miR-505 in vivo experiments. Overall, a relatively lower miR-505 and higher HMGB1 expression in RCC specimens and cell lines were found. HMGB1 was verified as a direct target of miR-505 by luciferase assay. In vitro, overexpression of miR-505 negatively regulates HMGB1 to suppress the proliferation in Caki-1; meanwhile, knock-down of miR-505 negatively regulates HMGB1 to promote the proliferation in 769P. In addition, in vivo overexpression of miR-505 could inhibit tumor cell proliferation in RCC by xenograft tumor formation. Therefore, miR-505, as a tumor suppressor, negatively regulated HMGB1 to suppress the proliferation in RCC, and might serve as a novel therapeutic target for RCC clinical treatment.
微小RNA已被证实可调节肾细胞癌（RCC）的多种生物学行为。尽管已有报道称miR - 505在几种人类肿瘤中发挥抑制作用，但其在RCC中的生理功能仍不清楚。因此，本研究对miR - 505在RCC中的作用及相关调控机制进行了研究。采用定量实时聚合酶链反应检测RCC组织和细胞系中miR - 505和高迁移率族蛋白B1（HMGB1）的表达。免疫组织化学染色用于评估RCC组织中HMGB1表达与增殖细胞核抗原（PCNA）表达之间的相关性。随后，使用细胞计数试剂盒 - 8增殖试验和5 - 乙炔基 - 2'-脱氧尿苷掺入法在体外测定miR - 505对增殖的影响。荧光素酶报告基因实验证实了miR - 505与HMGB1相关性背后的分子机制。异种移植瘤形成用于反映体内实验中miR - 505的增殖能力。总体而言，在RCC标本和细胞系中发现miR - 505表达相对较低，而HMGB1表达较高。荧光素酶报告基因实验证实HMGB1是miR - 505的直接靶点。在体外实验中，miR - 505过表达通过负向调节HMGB1抑制Caki - 1细胞增殖；同时，敲低miR - 505通过负向调节HMGB1促进769P细胞增殖。此外，体内实验中miR - 505过表达通过异种移植瘤形成抑制RCC肿瘤细胞增殖。因此，miR - 505作为一种肿瘤抑制因子，通过负向调节HMGB1抑制RCC增殖，可能成为RCC临床治疗的新靶点。
