TRIM16 inhibits proliferation and migration through regulation of interferon beta 1 in melanoma cells

// Selina K. Sutton 1 , Jessica Koach 1 , Owen Tan 1 , Bing Liu 1 , Daniel R. Carter 1 , James S. Wilmott 2 , Benafsha Yosufi 2 , 3 , Lauren E. Haydu 3 , Graham J. Mann 2 , 3 , John F. Thompson 3 , Georgina V. Long 2 , Tao Liu 1 , Grant McArthur 4 , 5 , Xu Dong Zhang 6 , Richard A. Scolyer 2 , 3 , Belamy B. Cheung 1 , Glenn M. Marshall 1 , 7 1 Children’s Cancer Institute, Lowy Cancer Research Centre, UNSW Australia, Sydney, Australia. 2 Melanoma Institute Australia and the University of Sydney, Sydney Australia. 3 Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Sydney and Discipline of Pathology, Sydney Medical School, The University of Sydney, Australia. 4 Molecular Oncology Laboratory, Oncogenic Signaling and Growth Control Program, Peter MacCallum Cancer Centre, East Melbourne, VIC 3002, Australia. 5 Sir Peter MacCallum Department of Oncology, The University of Melbourne, Parkville, VIC 3010, Australia. 6 Priority Research Centre for Cancer Research, Oncology and Immunology Unit, University of Newcastle, NSW, Australia. 7 Kids Cancer Centre, Sydney Children’s Hospital, Sydney, Australia. Correspondence to: Dr. Glenn M. Marshall, e-mail: g.marshall@unsw.edu.au Dr. Belamy B. Cheung, e-mail: bcheung@ccia.unsw.edu.au Keywords: Melanoma, TRIM16, BRAF inhibitor, cell migration, IFNβ1 Received: July 29, 2014      Accepted: September 07, 2014      Published: September 20, 2014 ABSTRACT High basal or induced expression of the tripartite motif protein, TRIM16, leads to reduce cell growth and migration of neuroblastoma and skin squamous cell carcinoma cells. However, the role of TRIM16 in melanoma is currently unknown. TRIM16 protein levels were markedly reduced in human melanoma cell lines, compared with normal human epidermal melanocytes due to both DNA methylation and reduced protein stability. TRIM16 knockdown strongly increased cell migration in normal human epidermal melanocytes, while TRIM16 overexpression reduced cell migration and proliferation of melanoma cells in an interferon beta 1 (IFNβ1)-dependent manner. Chromatin immunoprecipitation assays revealed TRIM16 directly bound the IFNβ1 gene promoter. Low level TRIM16 expression in 91 melanoma patient samples, strongly correlated with lymph node metastasis, and, predicted poor patient prognosis in a separate cohort of 170 melanoma patients with lymph node metastasis. The BRAF inhibitor, vemurafenib, increased TRIM16 protein levels in melanoma cells in vitro , and induced growth arrest in BRAF-mutant melanoma cells in a TRIM16-dependent manner. High levels of TRIM16 in melanoma tissues from patients treated with Vemurafenib correlated with clinical response. Our data, for the first time, demonstrates TRIM16 is a marker of cell migration and metastasis, and a novel treatment target in melanoma.