Two prognostic factors in breast cancer: Novel functions of EGFR and beta-catenin

Shiaw-Yih Lin, The University of Texas Graduate School of Biomedical Sciences at Houston


In this study, we demonstrated the novel functions of two important prognostic markers in breast cancer, EGFR and [special characters omitted]-catenin in proliferation and/or other transformation phenotype. First we demonstrated that EGFR could be detected in the nucleus in highly proliferating tissues, including primary breast cancer samples and a breast cancer cell line. We found that EGFR contained a strong transactivation domain, complexed with an AT-rich consensus DNA sequence and activated promoters containing this sequence, including cyclin D1 promoter. Therefore, EGFR may function as a transcription factor to activate genes required for highly proliferating activity such as cyclin D1 in breast cancer. In the second part of this study, we identified [special characters omitted]-catenin as an important prognostic factor in breast cancer. We found that cyclin D1 was one of the genes regulated by [special characters omitted]-catenin in breast cancer cells. The transactivation activity of [special characters omitted]-catenin correlated significantly with cyclin D1 expression in both breast cancer cell lines and in breast cancer patient samples, in which high [special characters omitted]-catenin activity correlated with poor prognosis of the patients. Moreover, blockage of [special characters omitted]-catenin activity significantly inhibited transformation phenotypes in breast cancer cells. Therefore, our results indicate that [special characters omitted]-catenin can be involved in breast cancer formation and/or progression and may serve as a target for breast cancer therapy.

Subject Area

Oncology|Cellular biology|Molecular biology

Recommended Citation

Lin, Shiaw-Yih, "Two prognostic factors in breast cancer: Novel functions of EGFR and beta-catenin" (1999). Texas Medical Center Dissertations (via ProQuest). AAI9951897.