Concomitance of oncogenic HPV types, CHEK2 gene mutations, and CYP1B1 gene polymorphism as an increased risk factor for malignancy.

ABSTRACT

INTRODUCTION: Urinary bladder carcinoma ranks the fourth position in malignancy incidence rates in men (6.1%) and the 17th position in women (1.6%). In general, neoplastic diseases should be approached from two perspectives prevention with implementation of prophylactic measures and early diagnostics. Prophylactics is possible in the preclinical phase of neoplasm, being both justified and plausible in patients from high-risk groups. Thus, it is particularly important to select such groups, not only by referring to environmental carcinogenic factors (occupational and extra-occupational) but also from genetic predisposition, which may be conductive for neoplasm formation. The mutations / polymorphisms of CHEK2 and CYP1B1 genes predispose to neoplasm via multiorgan mechanisms, while the human papilloma virus (HPV) may participate in the neoplastic transformation as an environmental factor. MATERIAL AND METHODS: 131 patients with diagnosed urinary bladder cancer were qualified to the study. Mutations/polymorphisms of CHEK2 (IVS2 + 1G > A gene, 1100delC, del5395, I157T) and CYP1B1- 355T/T were identified by the PCR in DNA isolated directly from the tumor and from peripheral blood. The ELISA test was used for the studies of 37 HPV genotypes in DNA, isolated tumour tissue. RESULTS: 11 mutations of CHEK2 gene were found, 355T/T polymorphism if CYP1B1 gene occurred in 18 patients (12.9%). Oncogenic HPV was found in 36 (29.3%), out of 123 examined patients. CONCLUSIONS: The concomitance of CHEK2 gene mutations or 355T/T polymorphism of CYP1B1 gene and the presence of oncogenic HPV types statistically significantly correlates with histological malignancy grades of urinary bladder carcinoma.