Identification of Novel Genes Affected by Gamma Irradiation Using a Gene-Trapped Library of Human Mammary Epithelial Cells

摘要

We propose that the expression of several unknown genes is affected by gamma radiation. Abnormal expression of these genes may be one of the early steps in breast carcinogenesis induced by radiation. We plan to establish an assay that will allow us to screen for breast cells that contain a single mutation by gene trapping. We will be able to detect changes in the expression or a gene upon treatment with different doses of radiation. These radiation- responsive genes will be identified through the rapid amplification of cDNA ends procedure and sequenced. Cells that are affected by radiation will be isolated and analyzed to see if the changes can lead to transformation of the normal breast epithelial cell into a neoplastic cell. This assay may prove to be a powerful tool in the identification of novel genes that are affected by gamma irradiation in the early stages of breast cancer progression. The 3'RACE protocol has recently been completed and thirty-one potential genes were sequenced. Of these, six candidate genes were found. They include: human creatine kinase gene, human androgen receptor, human DORA reverse strand protein 1 (DREV1), human eukaryotic translation elongation factor 1 beta 2 (EEF1B2), human ribosomal protein L27, and human DNA clone RP11-290F20 on chromosome 20. These genes will be further analyzed for their transformation properties of human mammary epithelial cells as discussed in the statement of work as well as their response to ionizing radiation.