Gastrokine 1 (GKN1) is a stomach-specific protein that is normally expressed in downregulated in gastric cancer. A research team led by Prof. LIU Siqi at Beijing Institute of Genomics(BIG), Chinese Academy of Sciences found that GKN1 can be detected in normal gastric cell but rarely appear in all the gastric cancer cell line. Through the experiment, GKN1 is a secretory protein that is probably secreted through the ER/Golgi pathway. And no matter expressed by E.coli or mammal cell, the GKN1 protein can induce the senescence of gastric cancer cell line but not in an immortalized gastric epithelial cell line. Oppositely, it can promote the growth of normal cells. Scientists found that GKN1 enabled senescence of gastric cancer cells through activation of P21waf and P16/Rb. Furthermore, sustained activation of Ras/Raf/MEK/ERK signalling was characterised in gastric cancer cells and a xenograft nude mouse model following GKN1 treatment. These results suggested GKN1 might be a potential novel target for gastric cancer diagnostics and therapeutics. This research results were published online in Gut First on 14 June 2011 Paper link: http://gut.bmj.com/content/early/2011/06/14/gut.2010.230623.abstract Comparison of the immunohistochemistry images between the tumour and its adjacent tissues using antibodies against GKN1. (a) Normal tissues; (b) tumour tissues.(Image by LIU's group) Growth curves of BGC-823, HeLa and GES-1 cells treated with GKN1 or control buffer, as determined by MTT assay. (Image by LIU's group) 
