Angiotensinogen Gene Promoter Variants And Kidney Cancer: 8d.07

Objective: Angiotensinogen (AGT)-derived peptides, as angiotensin II, regulate renal biology and physiology. Two novel AGT gene promoter variants (G-175A and G-163A) influence AGT gene expression in adipocytes as recently published. Moreover, obesity has been consistently linked to renal cell cancer. In a small population of kidney cancer patients studied mainly to obtain visceral adipose tissue samples, we have found a very high prevalence of -175A and -163A AGT gene variants.The aim of the present study was to compare the frequencies of these alleles in populations with or without kidney cancer. Design and Method: Three populations differing in size and gender were studied: 1075 healthy men of the Olivetti Heart Study (OHS) from southern Italy, 91 obese females, and 35 consecutive patients (both males and females) with kidney cancer from center Italy. The allele frequencies of G-175A and G-163A were evaluated. The known -20A/C SNP was used as control AGT promoter SNP. Results: AGT -163A and -175A variants were significantly more common with a striking 8-fold (for tha -163A) to 26-fold (for the -175A) difference in kidney cancer patients than in OHS males (P = 0.001) or obese female subjects (P = 0.001). Indeed, comparing allele frequencies we found that the -163A allele was 2.9% in OHS, 3.3% in obese females and 24.3% in kidney cancer patients (P = 0.001). The frequency of -175A allele was 1.8% in OHS, 1.1% in obese female but a striking 37.1% in kidney cancer patients (P = 0.001). No differences were found comparing -163A and -175A frequencies of OHS and obese females despite the differences in gender and size of populations. In kidney cancer patients no allele frequencies differences were found comparing males (n = 26) and females (n = 9). No differences in A-20C allele frequencies were found among the three different populations. Conclusions: Two novel AGT gene promoter functional variants are dramatically more frequent among kidney cancer patients suggesting a link between these genetic markers and renal cancer maybe through altered AGT expression in adipose tissue.