What Causes Cancer Mutations Essay Example | Topics and Well Written Essays - 1500 words

What Causes Cancer Mutations - Essay Example As genes are the basic control machine of the cells, alteration of any kind may bring devastating consequences, or malignancy. When compared with the normal cells, where damage of any kind is taken care by the repair system, tumor cells do not have any repair mechanism for the damaged DNA and there is a constant proliferation of cells without displaying senescence hence, generating a series of abnormal cells, with altered cellular pathways for uncontrolled proliferation, figuring malignant tumors (Alberts 2007; Katzang et al. 2009). The Genesis of a Cancer Cell A normal cell turns into a cancer cell because of one or more mutations in its DNA, which can be inherited or acquired. Mutation is sudden abrupt changes that occur in the genetic material i.e. the DNA of the cell. This genetic material is facilitated by various agents called mutagens. Mutagens can be either physical agents such as UV radiations, X-rays etc or they could be some chemical agents which are capable of producing c hanges in the cell by reacting with cellular macromolecules. These chemical agents form bond with the cellular macromolecules, thereby alter their normal structures. If they combine with the genetic material, the peptide formation is affected. Thus, these mutagenic agents affect the normal well being of the cell and when such a defective cell replicates the cellular modification is also passed on. These cellular alterations may lead to cancer, where the carcinogenic agents (cancer causing) are capable of altering the cell division leading to the uncontrolled proliferation of the cell (Alberts 2007; Chemical Carcinogens, Web.). In case of the breast cancer, woman who inherits a single defective copy of either of these tumor suppressor genes BRCA1 and BRCA2 displays an augmented risk of developing breast cancer. However, carcinogenesis is a complex, multistage process, usually involving more than one genetic change. Other epigenetic factors responsible for carcinogenesis involve epige netic factors, such as level of hormones in the body, exposure to carcinogens and tumor promoting agents. These epigenetic factors do not produce cancer by themselves but enhances the likelihood of genetic mutation(s) resulting in cancer (Katzang et al. 2009). These genetic changes are categorized as - A. The activation of proto-oncogenes to oncogenes: Proto-oncogenes are the normal genes present in the cells and are responsible for controlling cell division, cell differentiation and apoptosis. A triggering factor such as a virus or exposure to any carcinogen brings malignant changes in the cell. B. The inactivation of tumor suppressor genes: A cell has the mechanism to protect itself from uncontrolled proliferation and tumor formation due to expression of genes called tumor suppressor genes. These genes possess the ability to suppress malignant changes and are also referred as antioncogenes. Mutation in proto-oncogenes or tumor suppressor genes results in the proliferation of tumor . Thus, a loss of function of tumor suppressor genes can be the critical event in carcinogenesis (Rang et al. 2007; Katzang 2009). More than 30 tumor suppressor genes as well as more than 100 dominant oncogenes have been found to be associated with various types of cancers (Rang et al. 2007). Characteristics of Cancer cells The genetic basis of cancer has been revealed through numerous animal models. The Cancer Genome Atlas aims at methodically differentiating the configurational source of cancer, through recognition of the genomic mutations linked with every cancer form. A corresponding progress and description forms the basis of understanding growth and external appearance of the cancer or tumor called the phenotype of the cancer, is essential for designing drugs that can