Evidence of familial inheritance in non-medullary thyroid cancer (NMTC) has accumulated over the last few decades. However, known variants account for a very small percentage of the genetic burden. Here, we focused on the identification of common pathways and networks enriched in NMTC families to better understand its pathogenesis with the final aim of identifying one novel high/moderate-penetrance germline predisposition variant segregating with the disease in each studied family. We performed whole genome sequencing on 23 affected and 3 unaffected family members from five NMTC-prone families and prioritized the identified variants using our Familial Cancer Variant Prioritization Pipeline (FCVPPv2). In total, 31 coding variants and 39 variants located in upstream, downstream, 5′ or 3′ untranslated regions passed FCVPPv2 filtering. Altogether, 210 genes affected by variants that passed the first three steps of the FCVPPv2 were analyzed using Ingenuity Pathway Analysis software. These genes were enriched in tumorigenic signaling pathways mediated by receptor tyrosine kinases and G-protein coupled receptors, implicating a central role of PI3K/AKT and MAPK/ERK signaling in familial NMTC. Our approach can facilitate the identification and functional validation of causal variants in each family as well as the screening and genetic counseling of other individuals at risk of developing NMTC.

Alterations in microRNA (miRNA) expression have been reported in different cancers. We assessed the expression of 754 oncology-related miRNAs in esophageal adenocarcinoma (EAC) and evaluated their correlations with clinical parameters. We found that miR-221 and 483-3p were consistently upregulated in EAC cases vs. controls (Wilcoxon signed rank test: miR-221 P<0.0001; miR-483-3p P<0.0001). Kaplan‒Meier analysis showed worse cancer-related survival in patients expressing high miR-221 or miR-483-3p levels in all EACs (log-rank P=0.0025 and P=0.0235, respectively). Higher miR-221 or miR-483-3p levels also correlated with advanced tumor stages (Mann‒Whitney P=0.0195 and P=0.0085, respectively). Moreover, we found that overexpression of miR-221 was associated with worse survival in the low-risk EAC group. A significantly worse outcome was associated with the combined overexpression of miR-221 and miR-483-3p (log-rank P=0.0410). To identify target genes modified by miRNAs, we evaluatedtheir expression in different EAC cell lines, we transfected the corresponding mimic RNA (miRVANA) for either miR-221 or miR-483-3p and performed RNA-seq analysis. We found converging dysregulated genes involved in cancer progression, apoptosis, ATP synthesis and angiogenesis in miRNA-overexpressing cell lines, including a long non-coding RNA associated with oncogenesis, i.e., MALAT1. In conclusion, miR-221 and 483-3p overexpression in EAC correlated with low cancer-related survival, indicating that they might be considered new biomarkers for patient stratification.