Abstract B67: Overexpression of claudin-3 tight junction protein in endometrial cancer cell lines and tumor tissues derived from African American women

Abstract

According to the American Cancer Society (2017), endometrial cancer is the most common type of reproductive tumor in the US. Notably, whereas the incidence of endometrial cancer is similar in women of different races, the mortality rate is significantly higher in African American women. Currently, the molecular etiology of this disease is not well understood nor is there an explanation as to the disparity between the clinical outcomes for African American women and women of other races. Thus, the purpose of the current study was to determine (1) the expression of claudin-3 mRNA and protein in a panel of endometrial cancer cell lines and (2) the expression of claudin-3 protein in matched pairs of normal and tumor tissues derived from African American women with endometrial cancer. RT-PCR was used to measure claudin-3 mRNA expression, and immunoblotting was used to evaluate claudin-3 protein levels. We observed overexpression of claudin-3 protein in 4 of the 10 endometrial cancer cell lines and in 4 of the 6 primary endometrial cancer tissues (relative to their matched normal control tissues). Consistent with the immunoblotting data, the levels of claudin-3 mRNA were elevated in the same 4 cell lines that showed overexpression of the protein. These data suggest that increased transcription of the claudin-3 gene is responsible for the elevated levels of the claudin-3 protein. Consistent observations of elevated claudin-3 gene expression may indicate its use as a diagnostic marker. The finding of claudin-3 overexpression in the majority of endometrial tumor tissues suggests a role for tight junction disruption in the development of endometrial cancer in African American women. Citation Format: Maria E. Cuevas, Maria C. Todd. Overexpression of claudin-3 tight junction protein in endometrial cancer cell lines and tumor tissues derived from African American women [abstract]. In: Proceedings of the Tenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2017 Sep 25-28; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2018;27(7 Suppl):Abstract nr B67.