Leucine Rich Repeat Containing Protein 3B (LRRC3B)

LRRC3B is an evolutionarily highly conserved leucine-rich repeat-containing protein, but its biological significance is unknown. LRRC3B expression was reduced in 88.5% of gastric tumors compared with normal adjacent tissues.LRRC3B was significantly hypermethylated in gastric tumors. Stable transfection of LRRC3B in SNU-601 cells, a gastric cancer cell line, inhibited anchorage-dependent and anchorage-independent colony formation, and LRRC3B expression suppressed tumorigenesis in nude mice. Microarray analysis of LRRC3B-expressing xenograft tumors showed induction of immune response–related genes and IFN signaling genes. LRRC3B is a putative tumor suppressor gene that is silenced in gastric cancers by epigenetic mechanisms and that LRRC3B silencing in cancer may play an important role in tumor escape from immune surveillance.