e15014 Background: Radiotherapy (RT) is one of the main treatments for prostate cancer (PC). The effectiveness of such therapy depends on the initial radioresistance of tumor cells, which is ensured by their certain molecular features, which include the genes copy number variation (CNV). Model experiments on cell cultures (obtained from surgical material) have shown that CNVs have high potential as predictors of RT sensitivity. However, this potential is limited by the high level of invasiveness in obtaining biomaterials. A possible solution to this problem lies in the transition to CNV study in the extracellular DNA (cfDNA) of blood plasma. The aim of the study was to screen predictors of radioresistant PC based on the genes CNV in cfDNA. Methods: The study included 400 patients with diagnosed PC (T2a-3bN0M0, st. II-III), 40 of them after RT had a state of biochemical relapse (RT was performed on a Novalis TX linear accelerator (Varian, USA) (TFDisoeff = 75 Gr), mean time to biochemical relapse 7.5 months). Blood samples were separated into plasma and cell fraction by centrifugation. Isolation of cfDNA from blood plasma was performed using a set of reagents “DNA-Plasma-M” (Russia). Determination of the relative CNV of 13 genes (CDK1, CCND3, CDKN1B, TP53, PTEN, BCL2, XRCC4, BAX, RBBP8, H2AX, BRCA2, RAD50, EP300) was performed using the Real-Time qPCR method. Differences were assessed using the Mann-Whitney test; the Benjamin-Hochberg correction was used to correct multiple comparisons. Results: In the group with biochemical relapse (n = 40), the CNV of genes CDK1, CDKN1B, RBBP8, XRCC4, BRCA2 and RAD50 was statistically significantly (p < 0.05) higher by 2.0 times, 2.3 times, 2.1 times, 1.4 times, 2.4 times and 2.8 times, respectively, relative to the CNV of these genes in the cfDNA of the group without relapse (n = 360). Conclusions: Thus, it was found that the CNV of 6 genes (CDK1, CDKN1B, RBBP8, XRCC4, BRCA2 and RAD50) may be a potential molecular marker of radiosensitivity of prostate tumors. Based on the obtained data, a low invasive method for determining the prostate tumors sensitivity to RT has been developed.
Predicting out bore prostate cancer focal laser ablation failure and biochemical relapse using the correlation with the surrounding tissue temperature parameters during treatment
