Molecular mechanisms in pathogenesis of cancerogenesis

Abstract

Introduction: The study of molecular mechanisms in the pathogenesis of cancerogenesis is caused by the fact that at this stage, the fight against cancerogenic pathologies has insufficient means of prevention, diagnosis and treatment. We still hope that in future the tumors could be explained, controled and treated. Purpose and objectives: To provide an overview of the bibliography of Molecular Mechanisms in cancer's pathophysiology, which will serve as a point of initiation in the prophylaxis and treatment of maligne tumors. In achieving our goal, we have to: 1. explore the role of genes responsible for carcinogenesis; 2. find out the role of growth factors and cellular proliferation in carcinogenesis; 3. discover the role of apoptosis in carcinogenesis; Materials and methods: The basis of the research was a bibliographic review of the main work, which reveals the pathogenesis of carcinogenesis. The sources we used are: textbooks, monographs, handbooks, aplied publications, standards, patents, reports, theses, statistical freports, indexesand summary documentation. The stages of study were: l.Introduction in the topic of the research; 2. Researches of different sources; 2. Processing and interpretation of selected ideas from bibliography; Results: A proto-oncogene is a normal gene that can become an oncogene due to the mutations or to the increased expression. A suppressor gene of tumor (an antioncogene), is a gene that protects the cell from the first step of the development of cancer. When these mutant genes cause the decrease of their function, the cell can lead to cancer, usually in combination with other genetic changes. Both the activation of ras oncogenes and the inactivation of several suppressor genes, including p53, have been observed in the development of human colon and lung tumors. The point mutations in key codons can activate ras proto-oncogene may occur at various stages of the carcinogenetic process. The mechanisms that include impaired expression of proto-oncogenes are manifested through gene amplification and chromosomal translocation or gene rearrangement. The amplification of proto-oncogenes is usually associated to late stages of tum or progression. The apoptosis is a cellular process that occurs in physiological and pathological conditions. Reduced apoptosis or its resistance plays a vital role in carcinogenesis. There are may ways a malignant cell to acquire reduction in apoptosis or apoptosis resistance. Generally, the mechanisms by which evasion of apoptosis accurs can be broadly divided into: 1 .disrupted balance of pro-apoptotic and anti-apoptotic proteins 2. reduced caspase function 3 .impaired death of receptor signaling the activation of growth factor that signal pathways through genetic alterations affecting these genes, contributes to the development and progression of many human cancers. The growth factors, defined as polypeptides that stimulate cell proliferation, are major growth-regulatory molecules for cells in culture and, probably, also for cells in vivo.The decreased requirement for specific growth factors is a common occurence in neoplastically transformed cells and can lead to a growth advantage, a cardinal feature of cancer cells. Conclusion: The study of the molecular mechanisms of carcinogenesis plays a main role in the development of new methods of diagnosis and treatment of cancer. The molecular mechanisms involved in carcinogenesis serve as oncogenetic markers used in modern techniques of diagnosis with high specificity. The drugs targeted on the elimination of pathological molecular mechanisms involved in carcinogenesis, find their place progressively in the treatment strategies of cancer.