Overexpression of Polycomb Protein BMI-1 in Human Specimens of Breast, Ovarian, Endometrial and Cervical Cancer

• Published in: Anticancer research Vol. 30; no. 5; pp. 1559 - 1564
• Main Authors: HONIG, A, WEIDLER, C, HÄUSLER, S, KROCKENBERGER, M, BUCHHOLZ, S, KÖSTER, F, SEGERER, S. E, DIETL, J, ENGEL, J. B
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Attiki International Institute of Anticancer Research 01-05-2010
• Subjects: Antineoplastic Agents - pharmacology; Biological and medical sciences; Breast Neoplasms - metabolism; Cell Differentiation; Cyclin-Dependent Kinase Inhibitor p16; Endometrial Neoplasms - metabolism; Female; Female genital diseases; Gene Expression Profiling; Gene Expression Regulation, Neoplastic; Gynecology. Andrology. Obstetrics; Humans; Immunohistochemistry - methods; Ki-67 Antigen - biosynthesis; Medical sciences; Neoplasm Proteins - metabolism; Nuclear Proteins - biosynthesis; Nuclear Proteins - physiology; Ovarian Neoplasms - metabolism; Phenotype; Polycomb Repressive Complex 1; Proto-Oncogene Proteins - biosynthesis; Proto-Oncogene Proteins - physiology; Repressor Proteins - biosynthesis; Repressor Proteins - physiology; Tumors; Uterine Cervical Neoplasms - metabolism; Endometrium cancer; Breast disease; BMI-1; Ovary cancer; Stem cell; Gene overexpression; Cancerology; Uterus; BMI1 gene; Polycomb protein; Female genital system; Uterine diseases; cancer stem cells; Tumor cell; Endometrium; Protooncogene; Human; PcG gene; ovarian cancer; Breast cancer; Malignant tumor; Protein; Female genital diseases; Mammary gland diseases; Ovarian diseases; C-Onc gene; endometrial cancer; Uterine cervix diseases; Cervical cancer; Cancer
• ISSN: 0250-7005; 1791-7530

The polycomb group (PcG) proteins form chromatin-modifying complexes that are commonly deregulated in cancer. The PcG protein BMI-I is overexpressed by various tumours and thus may contribute to malignant transformation. The current study investigated the expression of BMI-I in human specimens of breast, ovarian, endometrial and cervical cancer.
Expression of BMI-I was evaluated in human ovarian cancer samples by Western blot analysis and immunohistochemistry (IHC) and compared to healthy ovarian tissue. BMI-I expression in human specimens of breast, endometrial and cervical cancer was evaluated by IHC and then compared with the respective benign tissues.
BMI-I was significantly (p<0.05) overexpressed in human breast, ovarian, endometrial and cervical cancer specimens as compared to benign controls. BMI-I expression was also more pronounced in the ovarian cancer samples as demonstrated by Western blot analysis. In human breast cancer samples, BMI-I expression was most pronounced in the invasion front of the tumour.
The current study showed for the first time that the BMI-I protein is significantly overexpressed in ovarian, endometrial and cervical cancer and may thus be a potential target for novel antitumor therapies.