RT Journal Article SR Electronic T1 Gastrokine 1 induces senescence through p16/Rb pathway activation in gastric cancer cells JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 43 OP 52 DO 10.1136/gut.2010.230623 VO 61 IS 1 A1 Xing, Rui A1 Li, Wenmei A1 Cui, Jiantao A1 Zhang, Jun A1 Kang, Bin A1 Wang, Yuan A1 Wang, Zhaohui A1 Liu, Siqi A1 Lu, Youyong YR 2012 UL http://gut.bmj.com/content/61/1/43.abstract 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.