bio- book report, part II

bio- book report, part II - The Genetics of Cancer Cancer...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
The Genetics of Cancer Cancer is one of today’s leading causes of death for many Americans. It is classified as a type of malignant growth or tumor, caused by abnormal or uncontrolled cell division and replication. Cancer had the capability of spreading to other parts of the body by utilizing the lymphatic or circulatory system. Cancerous tumors are either caused by carcinogens adept at mutating certain genes, or spontaneous mutations caused by an absence of tumor suppressor genes or overexpression of dominant oncogenes. At the rate of spontaneous mutation and based on the number of cells in body, every individual would contain an average of 100,000 cancer cells (Gibbs, p. 3). Recent research efforts have focused on the nature of the cell’s internal mechanisms that would cause irrepressible cell replication, due to genetic mutations in the cell’s DNA. Normal cells only divide when they receive a specific signal to do so: it is not a random process. Proper signals called growth factors circulate in the blood stream, or are generated from within the cell itself. Growth factors determining and regulating a cell’s growth from outside the cell can transmit a signal by binding to an appropriate receptor site on the cell’s surface to trigger a signaling system to activate specific genes in the nucleus to prepare for cell division and replication (Coleman, p. 31-32). The process of cell division is accomplished successfully through a series of checkpoints throughout the sequence of steps of the mitotic cycle to make sure everything phase has been completed accurately (Coleman, p. 32). In a cancer cell, this mitotic division becomes unregulated due to defective checkpoints, which are supposed to determine replication accuracy (Dooley, p. 8-9). The cell becomes defective as a result of gene mutations in its chromosomal information.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Normal genes are considered mutated when part of its genetic code is deleted, rearranged, or is translocated. These small defects that can occur in the DNA can result in the production of damaged proteins. The gene mutation allows the affected cell to begin replicating uncontrollably until it can invade the tissues, or metastasize to different areas of the body (Dooley, p.6). Certain conditions need to be met in order for a defective cell and gene to result in cancer. The gene must be mutated, or unrepaired, and the mutation must generate functionally altered proteins, which should provide a reproductive advantage to the cell. The mutation needs to occur in a long-lived stem cell with proliferating capability (Greaves, p. 48-49). Gene mutations resulting in cancerous growth are classified into two categories.
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/25/2012 for the course BIO 1421 taught by Professor Farr during the Fall '08 term at Texas State.

Page1 / 6

bio- book report, part II - The Genetics of Cancer Cancer...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online