The role of PGP9.5 as a tumor suppressor gene in human cancer

Yutaka Tokumaru, Keishi Yamashita, Sook Kim Myoung, Hannah L. Park, Motonobu Osada, Masaki Mori, David Sidransky

Research output: Contribution to journalArticlepeer-review

50 Scopus citations


PGP9.5 is a controversial molecule from an oncologic point of view. We recently identified frequent methylation of PGP9.5 gene exclusively in primary head and neck squamous cell carcinoma (HNSCC), suggesting that it could be a tumor suppressor gene. On the other hand, PGP9.5 was reported to be overexpressed in a subset of human cancers presumably due to intrinsic oncogenic properties or as a result of transformation. To demonstrate that PGP9.5 possesses tumor suppressive activity, we examined forced expression by stable transfection of PGP9.5 in 4 HNSCC cell lines. Although all 4 cell lines demonstrated reduced log growth rates in culture after transfection, only 2 cell lines with wild type p53 (011, 022) demonstrated decreased growth in soft agar. In 2 cell lines with mutant p53 (013, 019), we observed no altered growth in soft agar and increased sensitivity to UV irradiation. We then tested for and found a high frequency of promoter methylation in a larger panel of primary tumors including HNSCC, esophageal SCC, gastric, lung, prostate and hepatocellular carcinoma. Our data support the notion that PGP9.5 is a tumor suppressor gene that is inactivated by promoter methylation or gene deletion in several types of human cancers.

Original languageEnglish (US)
Pages (from-to)753-759
Number of pages7
JournalInternational Journal of Cancer
Issue number4
StatePublished - Aug 15 2008


  • Apoptosis
  • Cancer
  • Methylation
  • PTP9.5
  • Tumor suppressor gene
  • Tumorigenesis

ASJC Scopus subject areas

  • Oncology
  • Cancer Research


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