LINE-1 retrotransposons become deregulated during the development of ovarian cancer precursor lesions.

In this study, we assessed LINE-1 open reading frame 1 protein expression in 12 p53 signature lesions, 32 STICs, and 112 various types of ovarian cancers via immunohistochemical staining and examined LINE-1 promoter methylation in representative cases. We found that 78% and 57% of STICs, with and without concurrent ovarian carcinomas, respectively, exhibited intense LINE-1 immunoreactivity compared to adjacent, normal-appearing fallopian tube epithelium. Hypomethylation of the LINE-1 promoter was found in all STICs exhibiting overexpression. None of the 12 p53 signatures demonstrated significant LINE-1 expression. In ovarian cancer, 84 (75%) of 112 ovarian carcinomas overexpressed LINE-1. Our results indicate that LINE-1 retrotransposons often become deregulated during progression of ovarian cancer precursor lesions from the p53 signature to STIC stages and remain highly expressed in carcinoma.
PMID: 30553834 [PubMed - as supplied by publisher]

Source: The American Journal of Pathology - December 13, 2018 Category: Pathology Authors: Pisanic TR, Asaka S, Lin SF, Yen TT, Sun H, Bahadirli-Talbott A, Wang TH, Burns KH, Wang TL, Shih IM Tags: Am J Pathol Source Type: research