Oncogenes and Breast Cancer - Term Paper Example

Thus, classification of tumors in diverse types and subtypes along with the identification of individuals who are at the potential risk of cancer is gaining prevalence. A combination of data procured from gene-expression and genomic information aids in the detection of possible new targets for designing high-throughput screening strategies for designing drugs that will lead to advances in cancer cell-targeted therapy. The present article deals with the importance of understanding for oncogenes to comprehend breast cancer.

Introduction Cancer is known as malignant neoplasm, the hallmark characteristic involves uncontrolled proliferation of cells. Under normal conditions cells grow, divide and die, but in a genetic defect called mutation occur in cancer cells leading to the formation of an abnormal DNA. 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). (Normal cell cycle) (Genetic mutation- causes alteration in genes) (Alberts 2007) Cancer cells manifest, to varying degrees, four characteristics that distinguish them from normal cells, comprising- uncontrolled proliferation, de-differentiation and loss of function, invasiveness and metastasis (Rang et al. 2007). 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.

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 epigenetic 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.

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 supp