PT - JOURNAL ARTICLE AU - Rui Xing AU - Wenmei Li AU - Jiantao Cui AU - Jun Zhang AU - Bin Kang AU - Yuan Wang AU - Zhaohui Wang AU - Siqi Liu AU - Youyong Lu TI - Gastrokine 1 induces senescence through p16/Rb pathway activation in gastric cancer cells AID - 10.1136/gut.2010.230623 DP - 2012 Jan 01 TA - Gut PG - 43--52 VI - 61 IP - 1 4099 - http://gut.bmj.com/content/61/1/43.short 4100 - http://gut.bmj.com/content/61/1/43.full SO - Gut2012 Jan 01; 61 AB - Background and aims Gastrokine 1 (GKN1) is a stomach-specific protein that is normally expressed in gastric mucosa but not in primary tumours and cell lines. Based on this evidence, it was presumed that GKN1 might play a role in gastric cancer development; however, its function and molecular mechanism are not clear. A systematic study was initiated that combined multiple approaches to define the molecular mechanism of GKN1 in gastric cancer cells.Method Proteomics, western blotting and immunohistochemistry were used to measure the expression level of GKN1. Western blotting combined with immunofluorescence was used to monitor the secretory process of this protein. Subsequently, the function and molecular mechanism of GKN1 was explored in vitro and in vivo.Results It was shown that GKN1 is an autocrine/paracrine protein and inhibits cell growth due to senescence, which resulted from activation of p16/Rb and p21waf pathways. Furthermore, sustained activation of Ras/Raf/MEK/ERK signalling was characterised in gastric cancer cells and a xenograft nude mouse model following GKN1 treatment.Conclusion These results provide comprehensive molecular evidence of GKN1 in inducing senescence of gastric cancer cells, and indicate that GKN1 might be a potential novel target for gastric cancer therapeutics.