GPRC5A overexpression predicted advanced biological behaviors and poor prognosis in patients with gastric cancer

G protein-coupled receptor, family C, group 5, member A (GPRC5A) had received attentions for its role in carcinogenesis and prognostic values in several types of cancer. However, the functional roles of GPRC5A in gastric cancer (GC) had never been elucidated. The expression levels of GPRC5A were detected by real-time quantitative reverse transcription PCR and Western blot in GC tissues and adjacent non-tumor tissues. GPRC5A expression in tissue sections of 106 GC samples was evaluated using immunohistochemistry. The staining results were compared with clinicopathological factors and to the prognosis of GC patients. The mRNA and protein expression levels of GPRC5A in gastric cancer tissues were higher than those in adjacent non-tumor tissues. Positive GPRC5A expression was significantly correlated with larger size of primary tumor, diffuse type (Lauren's classification), deeper serosal invasion, and more lymph node metastasis. In addition, Kaplan-Meier curve analysis demonstrated that GC patients with positive GPRC5A expression had poor prognosis than those with negative GPRC5A expression. GPRC5A expression was identified as an independent factor of the overall survival in GC patients by multivariate Cox analysis. Further, the overall survival difference existed between patients with GPRC5A positive and negative groups in GC patients with lymph node metastasis. Our results suggested that elevated levels of GPRC5A played significant roles in GC progression. GPRC5A could serve as a prognostic biomarker of GC.

G蛋白偶联受体C家族第5组成员A（GPRC5A）因其在多种癌症的致癌作用和预后价值而受到关注。然而，GPRC5A在胃癌（GC）中的功能作用尚未阐明。通过实时定量逆转录PCR和蛋白质印迹法检测胃癌组织及相邻非肿瘤组织中GPRC5A的表达水平。采用免疫组织化学方法评估106例胃癌样本组织切片中GPRC5A的表达。将染色结果与临床病理因素以及胃癌患者的预后进行比较。胃癌组织中GPRC5A的mRNA和蛋白质表达水平高于相邻非肿瘤组织。GPRC5A阳性表达与原发肿瘤较大、弥漫型（ Lauren分类）、浆膜浸润更深以及更多淋巴结转移显著相关。此外，Kaplan - Meier曲线分析表明，GPRC5A表达阳性的胃癌患者比GPRC5A表达阴性的患者预后差。多变量Cox分析确定GPRC5A表达是胃癌患者总体生存的一个独立因素。此外，在有淋巴结转移的胃癌患者中，GPRC5A阳性组和阴性组患者之间存在总体生存差异。我们的研究结果表明，GPRC5A水平升高在胃癌进展中起重要作用。GPRC5A可作为胃癌的一种预后生物标志物。