There was complete concordance between p53 gene mutation and p53 protein accumulation in the 15 snap-frozen carcinomas and in both breast carcinoma cell lines.
Some recent data on the Wilms' tumor gene, WT1, and on the involvement of the p53 gene in breast cancer are presented, and the importance of genomic imprinting in contributing to the excess of suppressor gene mutations in chromosomes of paternal origin is considered.
One germ-line mutation was found in 136 patients and so we conclude that constitutional mutation of p53 may be an uncommon etiological factor in breast cancer.
We have investigated the expression of ras p21, Rb1 and p53 proteins in human breast cancer patients immunohistochemically, and correlated the results with a range of clinical and pathological parameters.
The p53 gene, a putative tumor suppressor gene located at 17p13, was examined for aberrations to determine whether it is the target for the 17p LOH in breast cancer.
There was no significant correlation with c-erbB-2 protein expression or retinoblastoma protein loss. p53 protein was detected in a high proportion of cells in three of the six comedo ductal carcinomas in situ studied but either not at all or at a lower level in tumours of the cribriform type. p53 mutations are common in breast carcinomas, but heterogeneity within individual tumours is frequent.
The presence of elevated levels of mutant p53 may itself be a prognostic factor in human breast cancer and activation of this oncogene may be important in the ability of a tumor to metastasize.
The cell lines MDA-MB 468 and T47 D contain only single mutated copies of the p53 gene, whereas the status of p53 in the breast cancer cell line MCF 7 remains equivocal.