Epigenetic identification of receptor tyrosine kinase-like orphan receptor 2 as a functional tumor suppressor inhibiting β-catenin and AKT signaling but frequently methylated in common carcinomas.

Abstract

Through subtraction of tumor-specific CpG methylation, we identified receptor tyrosine kinase-like orphan receptor 2 (ROR2) as a candidate tumor suppressor gene (TSG). ROR2 is a specific receptor or co-receptor for WNT5A, involved in canonical and non-canonical WNT signaling, with its role in tumorigenesis controversial. We characterized its functions and related cell signaling in common carcinomas. ROR2 was frequently silenced by promoter CpG methylation in multiple carcinomas including nasopharyngeal, esophageal, gastric, colorectal, hepatocellular, lung, and breast cancers, while no direct correlation of ROR2 and WNT5A expression was observed. Ectopic expression of ROR2 resulted in tumor suppression independent of WNT5A status, through inhibiting tumor cell growth and inducing cell cycle arrest and apoptosis. ROR2 further suppressed epithelial-mesenchymal transition and tumor cell stemness through repressing β-catenin and AKT signaling, leading to further inhibition of tumor cell migration/invasion and increased chemo-sensitivity. Thus ROR2, as an epigenetically inactivated TSG, antagonizes both β-catenin and AKT signaling in multiple tumorigenesis. Its epigenetic silencing could be a potential tumor biomarker and therapeutic target for carcinomas.

• Authors: Lili Li, Jianming Ying, Xin Tong, Lan Zhong, Xianwei Su, Tingxiu Xiang, Xingsheng Shu, Rong Rong, Lei Xiong, Hongyu Li, Anthony T C Chan, Richard F Ambinder, Yajun Guo, Qian Tao
• Journal: Cellular and molecular life sciences : CMLS (Cell Mol Life Sci) Vol. 71 Issue 11 Pg. 2179-92 (Jun 2014) ISSN: 1420-9071 [Electronic] Switzerland
• PMID: 24158497 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Proto-Oncogene Proteins
• WNT5A protein, human
• Wnt Proteins
• Wnt-5a Protein
• beta Catenin
• ROR2 protein, human
• Receptor Tyrosine Kinase-like Orphan Receptors
• Proto-Oncogene Proteins c-akt

Topics

• Carcinogenesis (genetics, metabolism, pathology)
• Carcinoma (genetics, metabolism, pathology)
• Cell Line, Tumor
• Cell Movement
• CpG Islands
• DNA Methylation
• Epigenesis, Genetic
• Epithelial-Mesenchymal Transition (genetics)
• Gene Expression Regulation, Neoplastic
• Humans
• Neoplasms (genetics, metabolism, pathology)
• Promoter Regions, Genetic
• Proto-Oncogene Proteins (genetics, metabolism)
• Proto-Oncogene Proteins c-akt (genetics, metabolism)
• Receptor Tyrosine Kinase-like Orphan Receptors (genetics, metabolism)
• Signal Transduction
• Wnt Proteins (genetics, metabolism)
• Wnt-5a Protein
• beta Catenin (genetics, metabolism)