Tissues acquire new or replacement cells through cell division. Orderly process is regulated in normal cells.
3 groups of cells:
- Permanent – unable to divide and reproduce
- Labile- cells in a constant state of renewal
- Stable – cells renewed slowly
- Orderly process in which proliferating cells are transformed into different and more specialized types of cells. The
- more specialized, the more likely it is to undergo mitosis
a normal gene regulating cell growth with the appropriate stimulus signaling time for cell division.
Tumor suppressor genes
Make proteins (“tumor suppressing proteins”) that stop the division of mutated cells.
DNA Repair Genes
- Affects cellular proliferation through their ability to repair nonlethal damages in other genes,
- proto-oncogenes, tumor suppressor genes, and genes that control apopotosis
Wilm’s tumor (nephroblastoma):
This cancer develops from loss of tumor suppression. In the fetus, rapidly dividing cells in the kidney tubules would be repressed by the tumor suppressing gene. If the gene is mutant, these cells continue to develop in the child’s tubules, resulting in Wilm’s tumor.
on surface of tumor cells or substances released by normal cells in response to the tumor
- hCG– testes
- CA125– ovarian
- PSA– prostate
- AFP– liver
- CEA– colorectal, pancreas, lung, stomach