A Joint Determination Of Gene Expression And Methylation For The Diagnosis Of Clear Cell Renal Cancer

Background. Clear cell renal cell carcinoma is the most frequent and most aggressive kidney cancer. Approximately 30 % at the initial diagnosis reveal distant metastases. This is due to the fact that kidney cancer in the early stages is asymptomatic. Very often (about 50 %), kidney cancer is detected by chance, during a routine examination or during treatment for other reasons. In this regard, the development of new methods of early diagnosis of clear cell renal cell carcinoma is actual.Materials and methods. The levels of mRNA expression and methylation of a number of genes in the surgical material of paired samples (normal kidney tissue and tumor, 21 clinical cases) were studied. Quantitative determination of gene expression was performed using real-time polymerase chain reaction on a Step One Plus instrument (Applied Biosystems, USA) using TaqMan (R) Gene Expression Assays (Applied Biosystems, USA). High molecular DNA was isolated from tissue by phenol-chloroform extraction. Methyl-specific polymerase chain reaction was performed on a T100 Thermal Cycler amplifier (Bio-Rad, USA).Results. As a result of joint analysis of the levels of gene expression and methylation, a system of potentially diagnostic markers has been developed, including the determination of the expression of a number of protein coding genes and the hypermethylation of several miRNA genes in tumor samples. Simultaneous determination of expression and methylation allows for the correct identification of tumors as SCRV with a sensitivity of 95.24 % (95 % confidence interval 76.18-99.88 %) and specificity of 95.24 % (95 % confidence interval 76.18-99.88 %).Conclusion. According to the results of the study, a system was developed based on the determination of the expression levels of the CA9, HIG2, EGLN3, NDUF4L2 genes and the methylation of the MIR9- 1, MIR34b/c, MIR124a-3, MIR129-2. Depending on the requirements for sensitivity, reliability of determination, or ease of implementation, various combinations of these genes are possible.