Molecular-biological marker Bcl-2 in colorectal cancer: the characteristics, the role of mechanisms regulating apoptosis, the effect on the prognosis (review of literature)

Abstract

Background. Many studies concerning molecular-biological markers in colorectal cancer (CRC) were performed over the past decade. Вcl-2 protein (B-cell lymphoma 2) was one of the most studied molecular-biological markers and attracted the attention of different specialties as on studying carcinogenesis and the relationship with prognosis. Aim. To study in details the characteristics of Bcl-2; to study Bcl-2 role in the mechanisms regulating apoptosis; to show update data concerning the prognostic significance of this protein in CRC. Materials and methods. To write this literature review we have studied domestic and foreign publications from Russian and international systems of search (PubMed, eLibrary, etc.) over the past 2-30 years. Results. The evaluation of the expression of antiapoptopic protein Вcl-2 in tumor can give additional information about the course of malignant process independently of therapeutic effects, the biological behaviour of the tumor: the rapidity of growth, the ability of invasion and metastasis (i.e. the prognosis of a disease). Conclusion. The results concerning the impact of abnormal expression of apoptosis inhibitor Вcl-2 on the course and prognosis of CRC have been accumulated in the scientific literature, but there have been only several studies, analyzing the relationship between Вcl-2 and metastasis of CRC and factors influencing the invasive potential of tumor cells. Nowadays, there is no consensus about the prognostic significance of protein Вcl-2 in patients with CRC. In some studies, concerning CRC, have been shown the correlation between Bcl-2 overexpression in tumor cells and a favorable course of disease and good survival in patients. Other authors have been shown that tumors with Bcl-2 overexpression, by contrast, are more aggressive in comparison with tumors without Bcl-2 expression. There are a number of studies in which the prognostic significance of Bcl-2 protein is not proved. Many issues, concerning the correlation between this molecular-biological marker and clinico-morphological characteristics of tumor, might also need to be itemized. All shown in the article is a subject to further research.