Decreased expression of TRPV1 in renal cell carcinoma: association with tumor Fuhrman grades and histopathological subtypes

Yong-Yang Wu,1 Xin-Yu Liu,2 De-Xiang Zhuo,1 Huai-Bin Huang,1 Fa-Biao Zhang,1 Shang-Fan Liao1 1Department of Urology, Affiliated Sanming First Hospital, Fujian Medical University, Sanming, Fujian 365100, China; 2State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University and Collaborative Innovation Center for Biotherapy, Chengdu, Sichuan 610041, China Purpose: The aim of this study was to investigate whether the expression of the ligand-gated Ca2+ channel transient receptor potential vanilloid type-1 (TRPV1) in primary human renal cell carcinoma (RCC) is associated with clinicopathological features.Patients and methods: Fresh and frozen primary tumor and normal peritumoral kidney tissues from 127 patients diagnosed with RCC were analyzed for TRPV1 expression by quantitative reverse transcription polymerase chain reaction (RT-PCR), Western blotting and immunohistochemistry.Results: Quantitative RT-PCR revealed that TRPV1 was decreased 3.20-fold in RCC tissue vs normal peritumoral kidney tissue (p=0.012). Significantly different TRPV1 mRNA expression was detected in RCC tissues of different Fuhrman grades and histopathological subtypes (F=4.282, p=0.015 and F=5.205, p=0.014, respectively). Decreased TRPV1 expression was correlated with RCC histopathological subtype (R=-0.554, p=0.003) and Fuhrman grade (R=−0.525, p=0.006). Western blot analysis of TRPV1 protein expression showed similar results. Immunohistochemical analysis showed strong expression of TRPV1 in kidney tubules but demonstrated weak or no immunostaining in RCC tissues.Conclusion: TRPV1 expression was decreased in RCC, which was significantly associated with tumor Fuhrman grades and histopathological subtypes. It seems to suggest that TRPV1 expression may be a valuable tool to predict the extent of RCC progression. Keywords: renal cell carcinoma, TRPV1, Fuhrman grade, histopathological subtype, prognostic factor&nbsp