Oncology: Cell Proliferation
Oncogene targets that have a direct effect on cell cycle, DNA repair or apoptosis can manifest their function through changes in adult skin fibroblast proliferation. Punch biopsies are taken of skin samples from the backs of mutant mice and cohort controls. These are developed into primary fibroblast cultures and the fibroblast proliferation rates are measured in a strictly controlled protocol. The ability of this assay to detect hyperproliferative and hypoproliferative phenotypes has been demonstrated with p53 (Jones SN, et al., 1996) and Ku80 (unpublished results).
The skin fibroblast proliferation assay uses the increase in the number of cells in a standardized culture as a measure of relative proliferative capacity. Primary fibroblasts are established from skin biopsies taken from wild type and mutant mice. Duplicate or triplicate cultures of 0.05 million cells are plated and allow to grow for six days. At the end of the culture period, the number of cells present in the culture is determined using an electronic particle counter.
Displayed below is a sample graph of how cell proliferation results are presented. In comprehensive phenotypic data packages graphs are interactive. Raw or calculated data and statistics can be seen by clicking on points in the graph.
Figure illustrates number of cells present in culture for female mutant mice. Cell counts for wild type littermates (green circle), homozygous (red diamond), and recent historical wild types (purple line) are plotted against long-term historical cell counts (± 2 standard deviations) for wild type animals (green shading). Recent wild type values are calculated from data collected within 60 days of current measures and long-term historical values are derived from data collected on more than 10,000 wild type mice.
Jones SN, Sands AT, Hancock AR, Vogel H, Donehower LA, Linke SP, Wahl GM, Bradley A. (1996) The tumorigenic potential and cell growth characteristics of p53-deficient cells are equivalent in the presence or absence of Mdm2, Proc Natl Acad Sci USA, 1996 93(24):14106-11.