Department of Respiratory Medicine, Nanjing Medical University Affiliated Hangzhou Hospital, Hangzhou First People's Hospital, Hangzhou, Zhejiang 310006, P.R. China.
Center for Molecular Medicine, Zhejiang Academy of Medical Sciences, Hangzhou, Zhejiang 310012, P.R. China.
Mol Med Rep. 2017 Nov;16(5):6382-6388. doi: 10.3892/mmr.2017.7343. Epub 2017 Aug 23.
Cellular tumor antigen p53 (p53) functions to maintain genomic stability and regulate cell apoptosis, while G protein‑coupled receptor class C group 5 member A (GPCR5A) is a lung cancer suppressor gene whose expression is induced by retinoids. The present in vitro study assessed the effects of p53 on the regulation of GPRC5A expression and on non‑small cell lung cancer (NSCLC) cells. Human NSCLC H1299 (p53‑null) and A549 (wild‑type p53) cell lines were subjected to p53 cDNA and small interfering (si)RNA transfection, respectively. GPRC5A expression was analyzed by reverse transcription‑quantitative polymerase chain reaction and western blotting, and cell behavior was analyzed using cell viability and apoptosis assays. The results of the present study demonstrated that knockdown of GPRC5A expression markedly upregulated tumor cell viability and reduced tumor cell apoptosis, while p53 overexpression in H1299 cells significantly increased the expression level of GPRC5A. p53 overexpression and GPRC5A induction markedly inhibited tumor cell viability and induced apoptosis, while knockdown of p53 resulted in a decrease in GPRC5A expression, inhibited tumor cell apoptosis and increased tumor cell viability. In serum‑free culture conditions, GPRC5A expression was decreased in the two cell lines; this decrease was less marked in p53 cDNA‑transfected H1299 cells and more marked in p53 siRNA‑transfected A549 cells. The results of the present study indicated that p53 antitumor activity may be mediated by GPRC5A in NSCLC cells.
细胞肿瘤抗原 p53(p53) 可维持基因组稳定性并调控细胞凋亡，而 G 蛋白偶联受体家族 C 第 5 组成员 A(GPCR5A) 是一种肺癌抑制基因，其表达受视黄酸诱导。本体外研究评估了 p53 对 GPRC5A 表达的调控作用及其对非小细胞肺癌(NSCLC)细胞的影响。分别用 p53 cDNA 和小干扰(si)RNA 转染人 NSCLC H1299(p53-缺失)和 A549(野生型 p53)细胞系。采用逆转录-定量聚合酶链反应和蛋白质印迹法分析 GPRC5A 的表达，通过细胞活力和细胞凋亡测定分析细胞行为。本研究结果表明，下调 GPRC5A 表达可显著上调肿瘤细胞活力并降低肿瘤细胞凋亡，而过表达 H1299 细胞中的 p53 可显著增加 GPRC5A 的表达水平。p53 过表达和 GPRC5A 诱导显著抑制肿瘤细胞活力并诱导细胞凋亡，而敲低 p53 导致 GPRC5A 表达减少，抑制肿瘤细胞凋亡并增加肿瘤细胞活力。在无血清培养条件下，两种细胞系中 GPRC5A 的表达均降低；在转染 p53 cDNA 的 H1299 细胞中降低程度较小，在转染 p53 siRNA 的 A549 细胞中降低程度较大。本研究结果表明，p53 的抗肿瘤活性可能通过 GPRC5A 在 NSCLC 细胞中发挥作用。
