Previous studies showed that upregulation of IWP-2 nmr LRIG1 expression in the superficial bladder cancer BIU-87 cell lines resulted in inhibition of cell proliferation and attenuation of cell invasive abilities, and played a tumor-suppressive role in vivo in bladder cancer [15, 16]. But the impact of LRIG1 on the biological behaviors of aggressive bladder cancer cells in vitro and the possible mechanisms of enhanced SAR302503 apoptosis induced by upregulation of LRIG1 is not very clear. In this study, we observed that LRIG1 expression appeared significantly downregulated,

but EGFR markly elevated in the majority of bladder cancer compared to human normal bladder tissue. Upregulation of LRIG1, followed by a decrease of EGFR on protein expression, induces cell apoptosis and cell growth inhibition, further reversing invasion in aggressive bladder cell lines. Finally, we demonstrated the capacity of upregulation of LRIG1 to inhibit downstream EGFR signaling in bladder cancer cells as manifested by markedly decreased expression of p-MAPK and p-AKT. Taken together, we conclude that restoration of LRIG1 to bladder cancer could offer a novel therapeutic strategy for suppression of receptor-positive bladder cancer. Materials and methods Tissue samples All of the

tissue specimens were obtained between November 2011 and September 2012 from 50 patients who underwent surgery for therapeutic treatment at Tongji Hospital. Immediately after the surgery, samples were snap-frozen in liquid nitrogen and stored STA-9090 cell line at -80°C. There were 45 bladder cancer and 5 normal bladder tissues in all of the specimens. As controls, biopsies of normal bladder samples were obtained from 5 patients who underwent transvesical prostatectomy. No treatment was given to the patients before surgery. The samples were sectioned for hematoxylin and eosin (H&E) staining for histological confirmation by the Department of Pathology of Tongji hospital. Tumor staging was determined according to the sixth

edition of the tumor node metastasis (TNM) classification of the International Union Against Cancer. This study was approved by the ethnics committee of Huazhong University of Science and Technology. All patients click here provided informed consent. Reagents and cell culture The plasmid p3XFLAG-CMV9-LRIG1 and rabbit antihuman LRIG1 polyclonal antibodies were generous gifts from Hakan Hedman (Umea University, Sweden). Two human aggressive bladder cancer cell lines(T24 and 5637) were used in this study. All of this cell lines were obtained from the American Type Cell Collection(ATCC), and grown in complete growth medium supplemented with 10% fetal bovine serum(FBS) and maintained in a humidified 5% CO2 atmosphere 37°C. Cell transfection The plasmid p3XFLAG-CMV9-LRIG1 was transfected into the two bladder cancer cells by using Lipofectamine2000 reagent (Invitrogen, Groningen, the Netherlands) according to the manufacturer’s instructions.