Cancer science
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TP53 mutations are a poor prognostic factor in breast cancers. The present study sets out to identify the gene set that determines the expression signature of the TP53 status (TP53 signature) and to correlate it with clinical outcome. Using comprehensive expression analysis and DNA sequencing of the TP53 gene in 38 Japanese breast cancer patients, a gene set from differentially expressed genes was isolated, depending on the TP53 status. ⋯ The TP53 signature is also a strong prognostic factor in the subgroups: estrogen-receptor positive, lymph node positive and negative, intermediate/high risk in St. Gallen criteria, and high risk in National Cancer Institute (NCI) criteria (log rank, P < 0.0001). TP53 signature is a reliable and independent predictor of the outcome of disease in operated breast cancer.
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A transgenic mouse model expressing Simian virus 40 T-antigen (SV40Tag) under the control of a tetracycline system was generated. In this model, a cerebellar tumor was developed after doxycycline hydrochloride treatment. Real time-polymerase chain reaction and immunohistochemistry results indicated that the SV40Tag gene was expressed in the tumor. ⋯ We also found that the SV40Tag could bind and translocate insulin receptor substrate 1 into the nucleus in primary cultured tumor cells. The interaction between the IGF pathway and SV40Tag may contribute to the process of malignant transformation in medulloblastoma. This transgenic animal model provides an important tool for studies on the signal pathways involved in the preneoplastic process in medulloblastoma and could help to identify therapeutic targets for brain tumors.