Cancer remains one of the main causes of human mortality despite significant progress in its diagnostics and therapy achieved in the past decade. Massive hypomethylation of retrotransposons, in particular LINE-1, is considered a hallmark of most malignant transformations as it results in the reactivation of retroelements and subsequent genomic instability. Accumulating data on LINE-1 aberrant methylation in different tumor types indicates its significant role in cancer initiation and progression. However, direct evidence that LINE-1 activation can be used as a cancer biomarker is still limited. The objective of this review was to critically evaluate the published results regarding the diagnostic/prognostic potential of the LINE-1 methylation status in cancer. Our analysis indicates that LINE-1 hypomethylation is a promising candidate biomarker of cancer development, which, however, needs validation in both clinical and laboratory studies to confirm its applicability to different cancer types and/or stages. As LINE-1 is present in multiple cell-free copies in blood, it has advantages over single-copy genes regarding perspectives of using its methylation status as an epigenetic cancer biomarker for cell-free DNA liquid biopsy.

This studyaimed to reveal the spectrum of BRca1 and BRca2 genes mutation in various ethnic groups of the Russian Federation. asystematic literature search includes data for the past 10 years and was conducted by using electronic databases of pubmed, eliBRaRY and ect.Material and methods.The review includes research data on the frequency of mutations of breast cancer-associated genes in various ethnic groups of the Russian Federation.Results.For «slavic» patients with a family history, the BRca1/2 mutation testing is the standard of care. in addition, the development of new antitumour drugs has resulted in improved survival rates. more than 1000 mutations of the BRca1 gene have been identified. Recent research is focused on the confirmation the beneficial effect of identified mutations. For the indigenous population (mongoloid ethnic groups), there are no standards for the treatment of inherited breast cancer. thus, the advances in molecular oncology for the treatment of hereditary breast cancer are not available for the indigenous population of the Russian Federation.Conclusion.In this context, the search for markers of early cancer detection and the development of criteria for therapy response are relevant for indigenous people. the development of new predictive and prognostic criteria of breast cancer among mongoloid ethnic groups with a family history will allow the innovative strategies for personalized molecular therapy to be developed.

Frequency of EGFR Mutations in Non-small Cell Lung Cancer Patients: Screening Data from West Siberia Non-small cell lung cancer;epidermal growth factor receptor;Western Siberia; Background: Incorporation of molecular analysis of the epidermal growth factor receptor (EGFR) gene into routine clinical practice has shown great promise to provide personalized therapy of the non-small cell lung cancer (NSCLC) in the developed world. However, the genetic testing of EGFR mutations has not yet become routine clinical practice in territories remote from the central regions of Russia. Therefore, we aimed to study the frequency of major types of activating mutations of the EGFR gene in NSCLC patients residing in West Siberia. Materials and Methods: We examined EGFR mutations in exons 19 and 21 in 147 NSCLC patients (excluding squamous cell lung carcinomas) by real time polymerase chain reaction. Results: EGFR mutations were detected in 28 of the 147 (19%) patients. There were 19 (13%) cases with mutations in exon 19 and 9 cases (6%) in exon 21. Mutations were more frequently observed in women (42%, p=0.000) than in men (1%). A significantly higher incidence of EGFR mutations was observed in bronchioloalveolar carcinomas (28%, p=0.019) and in adenocarcinomas (21%, p=0.024) than in large cell carcinomas, mixed adenocarcinomas, and NOS (4%). The EGFR mutation rate was much higher in never-smokers than in smokers: 38% vs. 3% (p=0.000). The frequency of EGFR mutations in the Kemerovo and Tomsk regions was 19%. Conclusions: The incorporation of molecular analysis of the EGFR gene into routine clinical practice will allow clinicians to provide personalised therapy, resulting in a significant increase in survival rates and improvement in life quality of advanced NSCLC patients.

BACKGROUND: The BRCA1 mutations that are endemic to the Slavic population of Russia have not been identified among indigenous peoples, including the Buryats, Tuvinians and Altaians with hereditary breast cancer. OBJECTIVE: This study was aimed to ide