Retinoid-inducible gene 1 (RIG1), also called tazarotene-induced gene 3, belongs to the HREV107 gene family, which contains five members in humans.
RIG1 is expressed in high levels in well-differentiated tissues, but its expression is decreased in cancer tissues and cancer cell lines. We found RIG1 to be highly expressed in testicular cells. When RIG1 was expressed in NT2/D1 testicular cancer cells, neither cell death nor cell viability was affected. However, RIG1 significantly inhibited cell migration and invasion in NT2/D1 cells. We found that prostaglandin D2 synthase (PTGDS) interacted with RIG1 using yeast two-hybrid screens. Further, we found PTGDS to be co-localized with RIG1 in NT2/D1 testis cells. In RIG1-expressing cells, elevated levels of prostaglandin D2 (PGD2), cAMP, and SRY-related high-mobility group box 9 (SOX9) were observed. This indicated that RIG1 can enhance PTGDS activity. Silencing of PTGDS expression significantly decreased RIG1-mediated cAMP and PGD2 production. Furthermore, silencing of PTGDS or SOX9 alleviated RIG1-mediated suppression of migration and invasion. These results suggest that RIG1 will suppress cell migration/invasion through the PGD2 signaling pathway. In conclusion, RIG1 can interact with PTGDS to enhance its function and to further suppress NT2/D1 cell migration and invasion. Our study suggests that RIG1-PGD2 signaling might play an important role in cancer cell suppression in the testis.
Written by:
Wu CC, Shyu RY, Wang CH, Tsai TC, Wang LK, Chen ML, Jiang SY, Tsai FM. Are you the author?
Department of Surgery, Tri-Service General Hospital, Taipei 114, Taiwan.
Reference: Biochim Biophys Acta. 2012 Dec;1823(12):2227-36.
doi: 10.1016/j.bbamcr.2012.08.013
PubMed Abstract
PMID: 22960220
UroToday.com Investigative Urology Section
