Renal cell carcinoma (RCC) is the second-most common uronephrological cancer. In the absence of specific symptoms, early diagnosis of RCC is challenging. Monitoring of the aberrant expression of tumour-associated antigens (TAAs) and related autoantibody response is considered as a novel approach of RCC diagnostics. The aim of this study was to examine the aberrant expression of arrestin-1 in renal tumours, to investigate the possible epigenetic mechanism underlying arrestin-1 expression, and to assess the frequency of anti-arrestin-1 autoantibody response. Immunohistochemistry was used to assess the presence of arrestin-1 in primary tumours and metastases of 39 patients with RCC and renal oncocytoma. Bisulfite sequencing was employed to analyse the methylation status of the promoter of the SAG gene encoding arrestin-1. Western blot analysis was performed to detect autoantibodies against arrestin-1 in serum samples of 36 RCC and oncocytoma patients. Arrestin-1 was found to be expressed in RCC (58.7% of cases) and renal oncocytoma (90% of cases) cells, while being absent in healthy kidney. The expression of arrestin-1 in RCC metastases was more prominent than in primary tumours. Hypomethylation of the SAG gene promoter is unlikely to be the mechanism for the aberrant expression of arrestin-1. Autoantibodies against arrestin-1 were detected in sera of 75% of RCC patients. Taken together, our findings suggest employment of autoantibody against arrestin-1 as biomarker of RCC.

肾细胞癌（RCC）是第二常见的泌尿科肾癌。在没有特定症状的情况下，RCC的早期诊断具有挑战性。监测肿瘤相关抗原（TAA）和相关自身抗体反应的异常表达被认为是RCC诊断的一种新方法。这项研究的目的是检查肾肿瘤中抑制素1的异常表达，研究抑制素1表达的潜在表观遗传机制，并评估抗抑制素1自身抗体反应的频率。免疫组化方法用于评估39例RCC和肾癌细胞瘤患者的原发性肿瘤和转移中是否存在抑制蛋白1。亚硫酸氢盐测序被用于分析编码抑制蛋白1的SAG基因的启动子的甲基化状态。进行了蛋白质印迹分析，以检测36例RCC和肿瘤细胞瘤患者血清样本中针对抑制蛋白1的自身抗体。发现Arrestin-1在RCC（占病例的58.7％）和肾癌细胞瘤（占病例的90％）细胞中表达，而在健康肾脏中则不存在。在原发性肿瘤中，RCC转移中restin-1的表达更为显着。SAG基因启动子的低甲基化不太可能是抑制素1异常表达的机制。在75％的RCC患者血清中检测到了针对抑制蛋白-1的自身抗体。综上所述，我们的研究结果表明使用针对抑制蛋白1的自身抗体作为RCC的生物标志物。7％的患者）和肾癌细胞瘤（90％的患者）细胞，而健康肾脏中则不存在。在原发性肿瘤中，RCC转移中restin-1的表达更为显着。SAG基因启动子的低甲基化不太可能是抑制素1异常表达的机制。在75％的RCC患者血清中检测到了针对抑制蛋白-1的自身抗体。综上所述，我们的研究结果表明使用针对抑制蛋白1的自身抗体作为RCC的生物标志物。7％的患者）和肾癌细胞瘤（90％的患者）细胞，而健康肾脏中则不存在。在原发性肿瘤中，RCC转移中restin-1的表达更为显着。SAG基因启动子的低甲基化不太可能是抑制素1异常表达的机制。在75％的RCC患者血清中检测到了针对抑制蛋白-1的自身抗体。综上所述，我们的研究结果表明使用针对抑制蛋白1的自身抗体作为RCC的生物标志物。