The genes CNV features in the tumor cells in patients with ovarian serous adenocarcinoma.

Abstract

e13641 Background: Serous adenocarcinoma is the most common subtype of ovarian cancer. Early diagnosis of this disease can significantly improve the prognosis. Development of more effective methods for early diagnosis and identification of more reliable markers require understanding the molecular mechanisms underlying the malignant behavior of ovarian epithelial cells. The aim of the study was to analyze the copy number variation (CNV) of genes that regulate apoptosis, DNA repair, cell proliferation, metabolism and estrogen reception in tumor and normal ovarian cells. Methods: For the study, we used tissue sections from FFPE blocks of 65 patients with serous ovarian adenocarcinoma diagnosis. Tumor and normal ovarian epithelial cells were isolated using laser microdissection with non-contact capture (Palm MicroBeam, Carl Zeiss). DNA was extracted from cells using the phenol-chloroform method. CNV of 33 genes (BRAF, KRAS, EGFR, PIK3CA, PTEN, TP53, BRCA1, BRCA2, PRKCI, NOTCH1, AKT1, BAX, CASP7, CASP3, CASP8, CASP9, MDM2, BCL2, CYP1A1, CYP1A1, CYP1A2, CYP1A2, CYP1A2, CYP1A1, CYP1A2, CYP1, ESR2, GPER, STS, SULT1A, SULT1E1, OCT4, SOX2, C-MYC, SOX18, SCNN1A) were determined by Real-Time qPCR method (reference B2M, GAPDH). Statistical analysis was performed using the Mann-Whitney test. For cluster analysis (Hierarchical Clustering, Euclidean distance) scripts in R were used. Results: A statistically significant (p < 0.005) increase in the CNV of PTEN, MDM2, SOX2, CYP1B1, ESR1, and SULT1E1 by 2.0, 2.0, 1.8, 2.5, 3.0 and 2.0 times, respectively, was found, as well as a 2.0-fold decrease in the CNV of CASP3 and CASP8 in tumor cells relatively to normal ones. Cluster analysis allowed us to distinguish 2 groups of serous adenocarcinoma samples that differed in gene CNV (p < 0.005): in group 1 (n = 40), the copy number of the SOX2, MDM2, ESR1, CYP1B1 and SULT1E1 genes was increased and the copy number of the TP53 and BRCA2 genes was reduced, in group 2 (n = 25), copy number of PTEN, PIK3CA, BCL2 was increased and copy number of BAX, CASP3 and CASP8 was lower. Conclusions: CNV analysis revealed the most characteristic markers of ovarian serous adenocarcinoma cells. Based on the differential CNV, 2 molecular subtypes of serous adenocarcinoma were distinguished.