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

Clin Cancer Res. 2017 Mar 1;23(5):1334-1345. doi: 10.1158/1078-0432.CCR-16-0947. Epub 2016 Sep 12.

Abstract

Purpose: 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.Experimental Design: 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.Results: The most distinctive methylome was observed for RETM918T-related tumors. Integration of methylation data with mRNA and miRNA expression data identified genes negatively regulated by promoter methylation. These in silico findings were confirmed in vitro for PLCB2, DKK4, MMP20, and miR-10a, -30a, and -200c. The mutation-specific aberrant methylation of PLCB2, DKK4, and MMP20 was validated in 25 independent MTCs by bisulfite pyrosequencing. The methylome and transcriptome data underscored JAK/Stat pathway involvement in RETM918T 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 RETM918T-bearing tumors (P < 0.02). Pharmacologic inhibition of STAT3 activity increased the sensitivity to vandetanib of the RETM918T-positive MTC cell line, MZ-CRC-1.Conclusions: 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 RETM918T MTCs. Clin Cancer Res; 23(5); 1334-45. ©2016 AACR.

MeSH terms

  • Carcinoma, Neuroendocrine / drug therapy
  • Carcinoma, Neuroendocrine / genetics*
  • Carcinoma, Neuroendocrine / pathology
  • DNA Methylation / genetics*
  • Female
  • Gene Expression Regulation, Neoplastic / genetics
  • Genome, Human
  • Genomics
  • Humans
  • Male
  • Mutation
  • Piperidines / administration & dosage
  • Proto-Oncogene Proteins c-ret / genetics*
  • Quinazolines / administration & dosage
  • STAT3 Transcription Factor / genetics*
  • Signal Transduction / genetics
  • Thyroid Neoplasms / drug therapy
  • Thyroid Neoplasms / genetics*
  • Thyroid Neoplasms / pathology

Substances

  • Piperidines
  • Quinazolines
  • STAT3 Transcription Factor
  • STAT3 protein, human
  • Proto-Oncogene Proteins c-ret
  • RET protein, human
  • N-(4-bromo-2-fluorophenyl)-6-methoxy-7-((1-methylpiperidin-4-yl)methoxy)quinazolin-4-amine

Supplementary concepts

  • Thyroid cancer, medullary