Specific Localization of Missense Mutations in the VHL Gene in Clear Cell Renal Cell Carcinoma.

Missense mutations in the VHL gene during sporadic clear cell renal cell carcinoma were studied to evaluate their localization in relation to functionally important motifs of the VHL protein. Somatic mutations were identified in 124 of 307 samples. All missense mutations in the α-domain were localized in the binding site for elongin C. Substitutions in the ß-domain (77%) were found in the HIF-binding site. Five missense mutations were absent in these sites, which illustrates their role in VHL protein formation or suppressor function of other protein cofactors. Mutation c.392A→T (p.N131I) was identified for the first time. Our results hold much promise to estimate the boundaries of functionally important sites in the VHL suppressor gene and contribute to the interpretation of a pathogenic role of mutations in direct DNA diagnostics.

[PCA3 AND TMPRSS2:ERG GENES EXPRESSION IN BIOPSIES OF BENIGN PROSTATE HYPERPLASIA, INTRAEPITHELIAL NEOPLASIA, AND PROSTATE CANCER].

Morphological analysis of the biopsies for prostate cancer (PCa) often is a difficult task due to heterogeneity and multifocality of tumors. At the same time, a lot of data exist about the potential molecular genetic markers of PCa. The aim of our study is to determine of PCA3 and TMPRSS2:ERG genes expression in benign hyperplasia (BPH), low and high grade intraepithelial neoplasia (PIN), PCa for revealing of diagnostic value of those genes expression in benign and precancerous changes in prostate. Total RNA was isolated from 53 biopsies, reverse transcription was performed, gene expression was determined by real time PCR (RT-PCR) then deltaCt index was determined as Ct(PCA3)--Ct(KLK3). Average deltaCt and its SD in BPH were 8.28 ± 3.13, low PIN--8.56 ± 2.64, high PIN--8.98 ±1.69, PCa--1.08 ± 2.36. We have demonstarted that deltaCt did not differ in patients with BPH, low and high grade PIN, whereas significantly increased in PCa relative to any of the three groups listed above (p < 0.0001). Expression of TMPRSS2:ERG was absent in BPH, PIN, but it was detected in 40% (4/10) of PCa cases. ROC-analysis showed that the AUC (area under ROC-curve with 95% CI, p < 0.0001) was 0.98 ± 0.02 in the analysis of a combination of overexpression of PCA3 and TMPRSS2:ERG. Thus, the expression analysis of the PCA3 and chimeric oncogene TMPRSS2:ERG in biopsy cannot be used for differential diagnosis of BPH, low and high grade PIN. However, overexpression of PCA3 and expression of TMPRSS2:ERG are characteristic in PCa. Expression analysis of these genes by the proposed RT-PCR modification at the threshold level deltaCt 3,22 has diagnostic accuracy 90% to detect PCa in biopsy specimens.