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

PURPOSE

The aim of this study was to investigate whether the expression of the ligand-gated Ca 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 (=0.012). Significantly different TRPV1 mRNA expression was detected in RCC tissues of different Fuhrman grades and histopathological subtypes (F=4.282, =0.015 and F=5.205, =0.014, respectively). Decreased TRPV1 expression was correlated with RCC histopathological subtype (R=-0.554, =0.003) and Fuhrman grade (R=-0.525, =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.