Mutations in the hedgehog pathway genes SMO and PTCH1 in human gastric tumors

PLoS One. 2013;8(1):e54415. doi: 10.1371/journal.pone.0054415. Epub 2013 Jan 18.

Abstract

The causal role of the hedgehog pathway in cancer has been best documented in basal cell carcinoma of the skin. To assess potential DNA alterations of the hedgehog pathway in gastric cancer, we sequenced SMO and PTCH1 genes in a set of 39 gastric tumors. Tumors were classified by histology based on the Lauren classification and Sanger sequencing was performed to obtain full length coding sequences. Genomic instability was evident in these tumors as a number of silent or missense mutations were found. In addition to those that are potential germline polymorphisms, we found three SMO missense mutations, and one PTCH1 frameshift mutation that are novel and have not been documented in basal cell carcinoma. Mutations were found in both intestinal and diffuse type gastric tumors as well as in tumors that exhibit both intestinal and diffuse features. mRNA expression of hedgehog pathway genes was also examined and their levels do not indicate unequivocal higher pathway activity in tumors with mutations than those without. In summary, SMO and/or PTCH1 mutations are present at low frequency in different histologic subtypes of gastric tumors and these do not appear to be driver mutations.

MeSH terms

  • Carcinoma, Basal Cell / genetics*
  • Carcinoma, Basal Cell / pathology
  • Gene Expression Regulation, Neoplastic
  • Genomic Instability
  • Humans
  • Mutation
  • Patched Receptors
  • Patched-1 Receptor
  • Receptors, Cell Surface / genetics*
  • Receptors, G-Protein-Coupled / genetics*
  • Signal Transduction / genetics
  • Smoothened Receptor
  • Stomach Neoplasms / genetics*
  • Stomach Neoplasms / pathology

Substances

  • PTCH1 protein, human
  • Patched Receptors
  • Patched-1 Receptor
  • Receptors, Cell Surface
  • Receptors, G-Protein-Coupled
  • SMO protein, human
  • Smoothened Receptor

Grants and funding

These authors have no support or funding to report.