The cell division process is dependent on a tightly controlled sequence of events. These events are dependent on the proper levels of transcription and translation of certain genes. When this process does not occur properly, unregulated cell growth may be the end result. Of the 30,000 or so genes that are currently thought to exist in the human genome, there is a small subset that seems to be particularly important in the prevention, development, and progression of cancer. These genes have been found to be either malfunctioning or non-functioning in many different kinds of cancer.
The genes that have been identified to date have been categorized into two broad categories, depending on their normal functions in the cell.
Genes whose protein products stimulate or enhance the division and viability of cells. This first category also includes genes that contribute to tumor growth by inhibiting cell death.
Genes whose protein products can directly or indirectly prevent cell division or lead to cell death.
The normal versions of genes in the first group are called proto-oncogenes. The mutated or otherwise damaged versions of these genes are called oncogenes. Note that by convention gene names are italicized and the proteins they make are not. As an example p53 refers to the gene and p53 refers to the protein.
The genes in the second group are called tumor suppressors.
Learn about oncogenes
Learn about tumor suppressors
Learn about microRNAs
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