Discuss how variation within the human genome might lead to cancer Essay

Discuss how variation within the human genome might lead to cancer - Essay Example These tumor cells are eventually able to invade neighboring tissue and spread further to other tissues via metastasis. Cancer begins after one cell undergoes one gene variation after another, until these collectively transform normal cells to uncontrollably dividing cancerous cells. Current research identifies the mutations that lead to cancer as occurring in two general genes; the proto-oncogenes and tumor suppressor genes, which normally accelerate and inhibit growth and division of cells respectively (Wong et al, 2011: p429). As a result, gene variations that over-activate proto-oncogenes and inhibit tumor suppressor genes drive the development of transformed cancer cells. These gene variants responsible for maintaining this transformed cancer phenotype are then selected for during tumorigenesis, causing cancer. Genetic instability has been identified as a fundamental hallmark of all cancerous cells. Genetic instability, in this case, is referent to increased frequency of genomic mutations. According to Almendro et al (2013: p283), this genetic instability can be seen at both the chromosomal level leading to deletions, translocations, amplifications, and aneuploidy of the entire chromosome, as well as at nucleotide level leading to point mutations. The two manifestations of genetic instability can result in an increase of mutation rates in cancerous cells through the alteration of protein function or expression. In the past five years, the most prevalent debate has been about whether changes to single nucleotides or abnormalities related to large macromolecular chromosomes tend to be more common in human cancer, as well as whether they are a causative factor in development of cancer (Almendro et al, 2013: p283). Alteration in chromosome number, also referred to as aneuploidy, is a critical characteristic of any cancers and is, in fact, one of the genetic alterations most observed in human cancers. Specific exchanges of chromosomes have been found to