Cancer Research
Research Toward a Cure
Insensitivity to Anti-Growth Signals
The second hallmark of cancer cells is the loss of response to signals that regulate cell growth. Cell division in normal cells is strictly controlled. However, this mechanism breaks down in cancer cells and leads to unrestrained tumor growth.
p53 Activation Assay on Odyssey® Infrared Imaging System
Tumor suppressor genes, e.g., p53 and Rb genes, can be inactivated by mutations, leading to cancer formation. About 80% of small cell lung cancers have an Rb mutation and 50-75% of all cancers have a p53 mutation.
Normal cell lines: WS1 (fibroblast cells) and 184V (mammary epithelial cells). Tumorigenic cell lines: MCF7 (mammary epithelial cells) and U2OS (osteosarcoma cells)
Quantitative determinations by the Odyssey® Imaging System show that Hdm2 levels were approximately the same in WS1, 184V, and MCF7 cells. The level of p53 in 184V cells was twice that of others. Relative expression level of Hdmx has been reported to either antagonize or augment Hdm2-mediated degradation of p53. The data showed that the p53 level in MCF7 cells was similar to that in WS1 cells, even though MCF7 cells have more than 5 times Hdmx:Hdm2 concentration compared to WS1 cells.
Reprinted with permission from Wang et. al. PNAS 104: 12365–12370 (2007)
