The diagnostic and biological implications of laminin expression in serous tubal intraepithelial carcinoma

There is compelling evidence to suggest that seroustubal intraepithelial carcinoma (STIC) is the likely primary sitefor the development of many pelvic high-grade serous carcino-mas (HGSCs). Identifying molecules that are upregulated inSTIC is important not only to provide biomarkers to assist inthe diagnosis of STIC but also to elucidate our understanding ofthe pathogenesis of HGSC. In this study, we performed RNAsequencing to compare transcriptomes between HGSC and nor-mal fallopian tube epithelium (FTE), and we identified LAMC1encoding laminin g1 as one of the preferentially upregulated genesassociated with HGSC. Reverse transcription polymerase chainreaction further validated LAMC1 upregulation in HGSC ascompared with normal FTE. Immunohistochemical analysis wasperformed on 32 cases of concurrent HGSC and STIC. The latterwas diagnosed on the basis of morphology, TP53 mutations, andp53 and Ki-67 immunohistochemical patterns. Laminin g1im-munostaining intensity was found to be significantly higher inSTIC and HGSC compared with adjacent FTE in all cases(P