Immunohistochemical Expression of P-Glycoprotein in Gynecologic Malignancies / 대한부인종양콜포스코피학회잡지

ABSTRACT

The expression of P-glycoprotein in gynecological tissues was studied by immunohistochemical staining methods. Aspects of study included the expression of P-glycoprotein in different tissues throughout the clinical treatment regimen, the relationship between the expression of P-glycoprotein and the degree of pathologic malignancy, and the expression of P-glycoprotein in cancerous tissue before and after chemotherapy. Studies were based on patients who were admitted to the Department of Obstetrics and Gynecology of Chungnam National University Hospital from January 1988 to December 1993. Tissue samples collected prior to chemotherapy included 34 ovarian cancers, 73 cervical cancers, and 11 endometrial cancers. Pre and post-chemotherapy tissue samples included 11 ovarian cancers and 15 cervical cancers. Normal tissue samples included 12 from the ovaries, 15 from the cervix, and 10 from the endometrium. RESULTS ARE AS FOLLOWS1. p-glycoprotein was mainly found in the cytoplasm of both normal tissue cells and cells of tissues prior to chemotherapy. After chemotherapy it was found more intensely in the cell membrane than in the cytoplasm. 2. For normal tissue, p-glycoprotein was found in 25% of ovarian tissues, 33.3% of uterine cervical tissues, and 40.0% of endometrial tissues. 3. For cancerous tissues prior to chemotherapy, p-glycoprotein was found in 45.5% of ovarian cancer cases, 47.9% of uterine cervical cancer cases, and 45.5% of endometrial cancer cases. There was no statistically meaningful difference in these rates in cancerous versus normal tissues. 4. The expression of P-glycoprotein in cancerous tissues prior to chemotherapy was not related to histologic type. 5. For ovarian cancer tissue, p-glycoprotien was expressed in 45.5% of cases prior to chemotherapy, and 54.4% of cases subsequent to chemotherapy. For uterine cervical cancer tissue, p-glycoprotein expression rates before and after chemotherapy was 46.7% and 60.0% respectively and there was a statistically meaningful difference(p<0.05). 6. There was no relationship between P-glycoprotein expression in cancer tissues after chermotherapy and the presence of cisplatin in chemotherapeutic drugs. 7. For uterine cervical cancer tissues prior to chemotherapy, there was no relationship between the degree histologic differentiation and the expression of P-glycoprotein. 8. For cancerous tissues there was no relationship between clinical stage and the expression of P-glycoprotein. In conclusion, the expression of P-glycoprotein was identified in the tissues before the drug exposure. However, there was no relationship between the expression of P-glycoprotein and hlstologic type, clinical stage, and effectiveness of chemotherapy, This may be related to P-glycoprotein inducing a cellular resistance to chemotherapeutic agents, although the importance of this resistance is thought to be small. Further studies of P-glycoprotein are needed to delineate its role in cellular anticancer drug resistance.