Expression of the organic cation transporter SLC22A16 can be a feature of human epithelial ovarian cancers with different histological type

Abstract

5131 Background: SLC22A16 is an organic cation transporter that is expressed on the plasma membrane of living cells and transports adriamycin into the cytoplasm. In this study, we examined SLC22A16 expression and evaluated its clinical significance in epithelial ovarian cancer. Methods: To evaluate the expression of SLC22A16 gene and protein, 12 ovarian cancer cell lines and 116 human tissues, including 94 ovarian cancers, 5 normal ovaries, 12 ovarian adenomas, and 5 borderline tumors were examined using immunohistochemistry, quantitative reverse transcription -PCR, and western blotting. Results: Positive immunoreactivity for SLC22A16 was detected on the plasma membrane of epithelial tumor cells. Positive immunoreactivity occurred in 15 of 94 (16%) ovarian cancer tissues, 2 of 5 (40%) borderline tumors, and 1 of 12 (8.3%) benign adenomas. Normal ovaries were all negative. The positive ovarian cancer tissues included 2 of 38 (5%) serous adenocarcinomas, 1 of 15 (6.7%) endometrioid adenocarcinomas, and 12 of 26 (20.4%) clear cell adenocarcinomas. SLC22A16 mRNA was significantly more expressed in clear cell adenocarcinomas than in tumors of other histological types (P<0.0001). Western blotting found immunoreactive bands corresponding to SLC22A16 in 10 out of 12 ovarian cancer cell lines. Conclusions: Our results suggest that adriamycin and related anthracyclines taken up through SLC22A16 have the potential to be effective treatment for clear cell adenocarcinoma. No significant financial relationships to disclose.