JAG1 is an Invasion and Metastasis promoting genes of Lung cancer

Background: JAG-1 is a ligand of Notch signaling and can regulate cell differentiation and proliferation in cancers. Recent studies indicated that JAG1 is a gene associated with cancer progression. Therefore, we investigated the role of JAG1 in lung cancer progression. Methods: The expression of JAG1 was manipulated by overexpression or RNA silencing in several human lung cell lines. The effect of JAG1 on tumorigenesis and invasion was assessed by the cell anchorage-independent growth, cell proliferation, cell migration and invasion assays in vitro as well as metastasis in vivo. The potential downstream genes of JAG1 were identified by oligonucleotide microarrays and quantitative reverse transcriptionVpolymerase chain reaction (RT-PCR). We further measured JAG1 expression in lung cancer specimens by RT-PCR. Correlation between JAG1 expression and overall survival of lung cancer patients was determined by using the log-rank test and multivariable Cox proportional hazards regression analysis. All statistical tests were two-sided. Results: JAG1 enhanced anchorage-independent growth, cell migration, invasion in the lower invasive cells, CL1-0. JAG1 also increased the capability of migration and invasion in the other two lung cancer cell lines (A549 and NCI-H226). The silencing of JAG1 inhibited migration and invasion activities of the higher invasive cells, CL1-5, by siRNA technology. The invasion-promoting activity of JAG1 was also demonstrated in vivo by using a mouse metastasis model. By microarray analysis, we found that the expression of heat shock 70kDa protein 2 (HSPA2) was activated by JAG1 overexpression and eliminated by JAG1 silencing. Moreover, lung cancer patients with high JAG1 expressing tumors had shorter overall survival than those with low-expressing tumors. Conclusion: JAG1 might be an oncogene which promotes colonogenesis and metastasis, and high JAG1 expression is associated with shorten survival in lung cancer.

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Chang WH, Ho BC, Hsiao YJ, Chen JS, Yeh CH, Chen HY, Chang GC, Su KY, Yu SL