Coiled-coil domain containing 68 (CCDC68) demonstrates a tumor-suppressive role in pancreatic ductal adenocarcinoma

Oncogene. 2015 Aug 6;34(32):4238-47. doi: 10.1038/onc.2014.357. Epub 2014 Nov 10.

Abstract

Using integrative genomics and functional screening, we identified coiled-coil domain containing 68 (CCDC68) as a novel putative tumor suppressor gene (TSG) in pancreatic ductal adenocarcinoma (PDAC). CCDC68 allelic losses were documented in 48% of primary PDAC patient tumors, 50% of PDAC cell lines and 30% of primary patient derived xenografts. We also discovered a single nucleotide polymorphism (SNP) variant (SNP rs1344011) that leads to exon skipping and generation of an unstable protein isoform CCDC68Δ(69-114) in 31% of PDAC patients. Overexpression of full length CCDC68 (CCDC68(wt)) in PANC-1 and Hs.766T PDAC cell lines lacking CDCC68 expression decreased proliferation and tumorigenicity in scid mice. In contrast, the downregulation of endogenous CCDC68 in MIAPaca-2 cells increased tumor growth rate. These effects were not observed with the deletion-containing isoform, CCDC68Δ(69-114).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Pancreatic Ductal / genetics*
  • Carcinoma, Pancreatic Ductal / metabolism
  • Carcinoma, Pancreatic Ductal / pathology
  • Cell Line, Tumor
  • Cell Proliferation / genetics
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Mice, SCID
  • Mutation
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Polymorphism, Single Nucleotide
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA Interference
  • Reverse Transcriptase Polymerase Chain Reaction
  • Transplantation, Heterologous
  • Tumor Burden / genetics
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism

Substances

  • CCDC68 protein, human
  • Protein Isoforms
  • Tumor Suppressor Proteins