The group of tumor suppressor genes includes genes encoding components of the DNA excision repair system, which plays an important role in maintaining the stability of the genome. The most important structural components of the DNA excision repair system are proteins encoded by the XPD, DPYD, and other genes.
50 women were examined with breast cancer, stages 3-4. The diagnosis of breast cancer was based on data from anamnesis, the results of X-ray, and morphological examinations. The age of the patients were from 27 to 74 years (mean age 54 ± 0.06 year). All patients received standard treatment. Patients received chemotherapy according to the CAF regimens (fluorouracil 600 mg/m2, doxorubicin 60 mg/m2, cyclophosphamide 600 mg/m2 on day 1, every 4 weeks) and FAC (fluorouracil 500 mg/m2, doxorubicin 50 mg/m2, cyclophosphamide 500 mg/m2 on the 1st day, every 3 weeks).
Two types of DNA genes were studied: XPD (XPD Lys751Gln) and DPYD (DPYD D949V and DPYD_14 (1236G> A)) in breast cancer patients. A normal allele of the DPYD D949V gene (D/D 98 + 23bpAsp/Asp) was found in all the patients examined, and no normal allele (A/A-247bp) of the DPYD_14 gene (1236G> A) was detected in any patient. Among the examined patients, the heterochromic allele (A/G 247 + 126 + 121bp) of the DPYD_14 gene (1236G> A) was detected in 72% (n = 36) patients, the mutation gene (G/G 126 + 121bp) DPYD_14 (1236G> A) - in 28% (n = 14) patients. Analysis of the Lys751Gln polymorphism of the DPDD gene of XPD and D949V showed that the incidence of variant genotypes was almost the same in BC patients: the allele of the XPD Lys/Lys gene (A/A-273bp) and the DPYD Asp/Asp allele (D/D-98 + 23bp) were found in 100% of patients; Heterozygous Lys/Gln (A/C-273 + 207 + 66bp) and mutational Gln/Gln (C/C-207 + 66bp) alleles of the XPD gene,
According to our data, the study of XPD Lys751Gln and DPYD D949V genes in patients with breast cancer is inadvisable. The mutating genes DPYD_14 (1236G> A) were determined. In this connection, it is possible to continue our studies, both to gain knowledge in the development of breast cancer, and to study the chemoresistance of breast cancer patients.
Clinical trial identification
Legal entity responsible for the study
Republican Cancer Research Center
All authors have declared no conflicts of interest.