Abstract 2187: Protocadherin 10, a novel tumor suppressor, suppresses tumorigenesis and liver metastasis of colorectal cancer cells in mice

Colorectal cancer (CRC) is one of the leading causes of cancer death in the world. By loss of heterozygosity approach, we identified Protocadherin 10 (PCDH10) gene with a high frequency of allelic deletion in CRC. Furthermore, the genetic alteration was associated with presence of distant metastasis and poorer overall survival of patients. Importantly, the expression of PCDH10 mRNA was silenced or downregulated in 37 (84.1%) out of 44 colorectal tumors as compared with their paired normal mucosa. We proposed that PCDH10 might be a CRC-associated tumor suppressor gene, and then investigated the biological functions of PCDH10 in CRC cells. First of all, re-expression of PCDH10 in HCT116 cells reduced cell proliferation, migration, invasion and anchorage-independent growth in vitro. Meanwhile, stable PCDH10- expressing cells (HCT116/PCDH10) exhibited suppression of tumorigenicity and liver metastasis in xenograft tumor models. In SCID mice, HCT116/PCDH10 cells with subcutaneous injection showed reduced tumor growth, and, with intrasplenic injection, showed reduced metastatic incidence and nodules in the liver, as compared with mock control cells. Taken together, these results indicate that PCDH10 is a tumor suppressor gene associated with CRC, and its downregulation might promote tumor progression and distant metastasis. In addition, allelic loss of PCDH10 gene could serve as a molecular predictor of metastasis and poor prognosis in patients with CRC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2187. doi:10.1158/1538-7445.AM2011-2187