Relative gene copy numbers in various patterns of cervical cancer growth.

Abstract

e18029 Background: Numerous studies on cervical cancer confirm an important role of specific genomic changes in the onset and development of cervical intraepithelial neoplasia and their effect on the progression of cervical cancer. Solid tumors are characterized by genomic changes leading to a change in the DNA sequence copy number. The purpose of the study was to reveal changes in the relative copy number of the ESR1, ESR2, GPER1, STS, SULT1A1, SULT1E1, CYP1A1, CYP1A2 genes responsible for the reception and metabolism of estrogens in cervical tissues in endophytic and exophytic patterns of tumor growth in order to find predictive markers of malignancy. Methods: The study included 40 patients aged 28-65 years with cervical cancer of endophytic (n = 20) and exophytic (n = 20) growth patterns. Eligibility criteria included a morphologically confirmed cervical squamous cell cancer T1b-2aN0M0, stage I-II. The Thermo Scientific GeneJET FFPE DNA Purification Kit was used for the DNA extraction from FFPE blocks of tumor and healthy tissues. DNA concentrations were measured on the Qubit 2.0 fluorimeter (Invitrogen, USA) using the Quant-iT dsDNA High-Sensitivity (HS) Assay Kit (Invitrogen, USA). Results: The relative copy number of the GPER1, SULT1A1, CYP1A1 genes in tumor samples increased (p < 0.05) compared with normal tissues in the total sample of patients diagnosed with cervical cancer. In contrast to the total sample, an increase in the SULT1A1 gene dosage did not reach a statistically significant level in any group (p = 0.242 and p = 0.157); the copy number of the GPER1 locus significantly increased only in the group with the endophytic growth pattern (p = 0.040), as well as the CYP1A2 gene dosage (p = 0.025). Patients of 36-55 years with endophytic tumors showed a statistically significant (p < 0.05) increase in the GPER1 and CYP1A1 gene copy numbers with the rates of 41.7% and 66.7%, respectively, as well as an increased amplification of the CYP1A2 gene in 41.67% of patients. In women of 56-75 years with endophytic tumors, an increase in the copy numbers of the ESR2, GPER1, SULT1A1 genes was observed with a frequency of 50%, 100% and 75%, respectively. Patients aged 20-35 and 36-55 years with exophytic tumors showed a statistically significant (p < 0.05) increase in the CYP1A1 gene copy numbers in 33.33% and 45.45%, respectively. Conclusions: The results suggest the use of the GPER1, SULT1A1 and CYP1A1 gene copy numbers as biomarkers of cervical tumors.