Multilayer OMIC Data in Medullary Thyroid Carcinoma Identifies the STAT3 Pathway as a Potential Therapeutic Target in RETM918T Tumors

Abstract

Medullary thyroid carcinoma (MTC) is a rare disease with few genetic drivers, and the etiology specific to each known susceptibility mutation remains unknown. Exploiting multilayer genomic data, we focused our interest on the role of aberrant DNA methylation in MTC development. We performed genome-wide DNA methylation profiling assessing more than 27,000 CpGs in the largest MTC series reported to date, comprising 48 molecularly characterized tumors. mRNA and miRNA expression data were available for 33 and 31 tumors, respectively. Two human MTC cell lines and 101 paraffin-embedded MTCs were used for validation. The most distinctive methylome was observed for -related tumors. Integration of methylation data with mRNA and miRNA expression data identified genes negatively regulated by promoter methylation. These findings were confirmed for, and miR-10a, -30a, and -200c. The mutation-specific aberrant methylation of , and was validated in 25 independent MTCs by bisulfite pyrosequencing. The methylome and transcriptome data underscored JAK/Stat pathway involvement in MTCs. Immunostaining [immunohistochemistry (IHC)] for the active form of signaling effector STAT3 was performed in a series of 101 MTCs. As expected, positive IHC was associated with-bearing tumors ( < 0.02). Pharmacologic inhibition of STAT3 activity increased the sensitivity to vandetanib of the -positive MTC cell line, MZ-CRC-1. Multilayer OMIC data analysis uncovered methylation hallmarks in genetically defined MTCs and revealed JAK/Stat signaling effector STAT3 as a potential therapeutic target for the treatment of MTCs..

Synergistic activity of everolimus and 5‐aza‐2′‐deoxycytidine in medullary thyroid carcinoma cell lines

“…Combined incubation with RET and mTOR inhibitors (AST487 and INK128, respectively) at low concentrations cooperated to inhibit mTOR signaling and cell growth, through the induction of apoptosis, in both MTC cell lines. In addition, a recent study found that methylation profiles relate closely to RET mutational status in MTC, and the most distinctive methylome was observed for RET‐M918T‐positive tumors (Mancikova et al ., ).…”

Role of tissue and circulating microRNAs and DNA as biomarkers in medullary thyroid cancer

“…Integration of methylation and miRNA expression data from MTC samples carrying RET M918T mutation, showed that miR-10a, miR-30a, and-200c expression levels were negatively correlated with their promoters' methylation. Pathway enrichment analyses of these miRNAs uncovered JAK/Stat pathway involvement in RET M918T MTCs (Mancikova, et al, 2017).…”

“…These data are in line with gene expression results by Ameur et al [paragraph 7. Genetic landscape of germline and somatic mutations in MTC] (Ameur, et al, 2009) and suggested that methylation profile relates to RET mutational status (Mancikova, et al, 2017). Although TERT mutations were not identified in MTC (Bae, et al, 2016;Romei, et al, 2016) , telomerase activation was detected in approximately 50% of sMTCs (Liu, et al, 2014).…”

“…DNA from frozen tissue was extracted using a phenol/chloroform procedure (Schagdarsurengin, et al, 2006;Schagdarsurengin, et al, 2002) or DNeasy Blood and Tissue Kit (Qiagen) (Mancikova, et al, 2017;. DNA from FFPE samples was extracted using DNeasy Blood and Tissue Kit (Qiagen) (Mancikova, et al, 2017; or QIAamp DNA FFPE protocol (Qiagen) (Shakiba, et al, 2019). DNA from cell lines was extracted using the DNeasy Blood and Tissue Kit (Qiagen) (Mancikova, et al, 2017;Vitale, et al, 2017;.…”

“…DNA from FFPE samples was extracted using DNeasy Blood and Tissue Kit (Qiagen) (Mancikova, et al, 2017; or QIAamp DNA FFPE protocol (Qiagen) (Shakiba, et al, 2019). DNA from cell lines was extracted using the DNeasy Blood and Tissue Kit (Qiagen) (Mancikova, et al, 2017;Vitale, et al, 2017;. DNA from MTC samples was initially modified with sodium bisulfite.…”