Transforming growth factors ß and their signaling pathway in renal cell carcinoma and peritumoral space-transcriptome analysis.

PURPOSE: The aim of the study was to verify hypotheses: Are transforming growth factors TGFß1-3, their receptors TGFßI-III, and intracellular messenger proteins Smad1-7 involved in the pathogenesis of kidney cancer? What is the expression of genes of the TGFß/Smads pathway in renal cell carcinoma (RCC) tissues, peritumoral tissues (TME; tumor microenvironment), and in normal kidney (NK) tissue?. METHODS: Twenty patients with RCC who underwent total nephrectomy were included into the molecular analysis. The mRNA expression of the genes was quantified by RT-qPCR. RESULTS: The study showed that the expression of the genes of TGFß/Smads pathway is dysregulated in both RCC and the TME: TGFß1, TGFß3 expression is increased in the TME in comparison to the NK tissues; TGFß2, TGFß3, TGFßRI, TGFßRIII, Smad1, Smad2, Smad3, and Smad6 are underexpressed in RCC comparing to the TME tissues; TGFßRI, TGFßRIII, and Smad2 are underexpressed in RCC in comparison to the NK tissues. CONCLUSION: On the one hand, the underexpression of the TGFß signaling pathway genes within the malignant tumor may result in the loss of the antiproliferative and pro-apoptotic activity of this cytokine. On the other hand, the overexpression of the TGFß/Smads pathway genes in the TME than in tumor or NK tissues most probably results in an immunosuppressive effect in the space surrounding the tumor and may have an antiproliferative and pro-apoptotic effect on non-neoplastic cells present in the TME. The functional and morphological consistency of this area may determine the aggressiveness of the tumor and the time in which the neoplastic process will spread.