Hidehisa Mori

The Involvement of Hepatocyte Growth Factor-MET-Matrix Metalloproteinase 1 Signaling in Bladder Cancer Invasiveness and Proliferation. Effect of the MET Inhibitor, Cabozantinib (XL184), on Bladder Cancer Cells

OBJECTIVE To clarify the invasive mechanisms of muscle-invasive bladder cancer (BCa) would be useful for the determination of appropriate treatment strategies. We previously showed that hepatocyte growth factor (HGF)-MET signaling is correlated with invasiveness of BCa cells. Here, we investigated the effects of the MET inhibitor, cabozantinib (XL184), on BCa cells. METHODS We first conducted Western blot analysis to investigate MET expression in BCa cell lines. Next, we examined the effect of cabozantinib on their proliferation and invasive abilities using MTT and Matrigel invasion assays, respectively. Invasion assays were performed using the xCELLigence system. Additionally, to investigate the biological function of HGF-MET signaling, we analyzed gene expression profiles and performed real-time polymerase chain reaction analyses of 5637 cells that were cultivated with or without HGF stimulation, with or without cabozantinib. RESULTS MET was highly expressed in 4 of 5 BCa cell lines, and 5637 and T24 cells showed especially high protein expression of MET. Cabozantinib suppressed cell proliferation and invasion (cell index; mock, 1.49 vs HGF, 2.26 vs HGF + XL184, 1.47, P < .05). Gene expression profile analysis indicated that matrix metalloproteinase 1 (MMP1) was significantly elevated at the mRNA level with addition of HGF. Moreover, cabozantinib suppressed HGF-induced MMP1 expression in 5637 T24 cells. CONCLUSIONS These data indicate that cabozantinib suppressed MMP1 expression by blocking HGF-MET signaling and that HGF-MET-MMP1 signaling is involved in the invasiveness and proliferation of BCa cells. These results suggest that cabozantinib might prove useful for future treatment of muscle-invasive BCa.

Complications of Flexible Ureteroscopic Treatment for Renal and Ureteral Calculi during the Learning Curve

Background: The flexible ureterorenoscope (URS) and associated devices have developed rapidly. However, despite its therapeutic benefits, URS may be associated with some complications. To the best of our knowledge, there are no studies discussing the complications of flexURS during the learning curve. Methods: A retrospective review of the records of patients who underwent flexURS from January 2005 to June 2013 was performed. To compare the complications after the introduction of flexURS, patients were divided into four groups based on the surgeons training experience, that is, based on the number of cases performed by the surgeon. A total of 219 cases underwent flexURS. Groups 1, 2, 3, and 4 included 35, 50, 50, and 84 cases, respectively. The complications were classified using the Clavien system (I-IV). Results: The mean operation time and stone-free rate were significantly different (p < 0.001, p = 0.013, respectively). The total complication rates were 13.6, 10, 8.3, and 3.2%, respectively (p = 0.068). The more the surgeons experience, the less was the complication rate. Despite our best efforts, the incidence of urosepsis was not reduced (p = 0.902). Conclusions: To reduce severe complications, it is necessary to have performed about 100 cases. Increased surgeon experience tended to decrease the risk of severe complications, but the incidence of urosepsis was not reduced.

Clinical Significance of Neoadjuvant Combined Androgen Blockade for More Than Six Months in Patients with Localized Prostate Cancer Treated with Prostate Brachytherapy.

Introduction: The aim of this study is to clarify the clinical significance of neoadjuvant combined androgen blockade (CAB) for ≥6 months in patients with localized prostate cancer. Patients and Methods: A total of 431 patients with localized prostate cancer who underwent prostate brachytherapy (BT) with or without neoadjuvant CAB for ≥6 months with mean follow-up time of 64.6 months (range 24-108 months) were evaluated retrospectively. Of those 431, 232 patients received BT in combination with neoadjuvant CAB for ≥6 months. Biochemical recurrence-free rates (BRFRs) in 364 patients with at least 3 years of follow-up were evaluated by log-rank test. Results: BRFR in patients with low-, intermediate- and high-risk prostate cancer were 98.1, 94.2 and 89.1%, respectively. In patients with intermediate-risk prostate cancer only, neoadjuvant CAB was significantly associated with BRFR (p = 0.0468). Especially in patients with intermediate-risk prostate cancer with radiation dose received by 90% of the prostate (D90) <180 Gy, neoadjuvant CAB exerted a favorable impact on BRFR (p = 0.0429). On multivariate analyses, neoadjuvant CAB and D90 were independent predictors of BRFR (p = 0.0061 and p < 0.0001, respectively). Conclusions: Neoadjuvant CAB for ≥6 months has a favorable impact on BRFR in patients with intermediate-risk prostate cancer, particularly in patients with relatively low radiation doses of D90.

MP72-06 CORRELATION OF THE INSULIN RECEPTOR EXPRESSION AND THE RESISTANCE TO VASCULAR ENDOTHELIAL GROWTH FACTOR RECEPTOR TYROSINE KINASE INHIBITORS IN ADVANCED CLEAR CELL RENAL CELL CARCINOMA

INTRODUCTION AND OBJECTIVES: Vascular endothelial growth factor receptor tyrosine kinase inhibitors (VEGFR-TKIs) demonstrate the significant efficacy for advanced clear cell renal cell carcinoma (ccRCC), however, it eventually becomes resistant to VEGFR-TKIs during the treatment. So far, the mechanisms for the resistance to VEGFR-TKIs remain to be fully elucidated. Previously we have identified the gene set which could predict poor prognosis of ccRCC patients (Takahashi M et.al., Proc Natl Acad Sci U S A., 98: 9754, 2001). We examined whether the insulin receptor (INSR) expression in the gene set may correlate with the resistance to VEGFR-TKIs. METHODS: The INSR expression was examined immunohistochemically in the nephrectomy specimens of the RCC patients (n1⁄433) who then received axitinib as the VEGFR-TKI and correlated with their survival outcome. We compared the INSR expression of the nephrectomy or metastasectomy specimens before and after the administration of VEGFR-TKIs in 5 cases. The INSR expression of the human renal glomerular endothelial cells (HGEC) was compared before and after the administration of axitinib by Western blotting. In addition, we established patient derived Xenograft model (PDX) of ccRCC. Tumors of PDX were resected when it regrew and showed the resistance for axitinib and the INSR expression was compared before and after the treatment by Western blotting. RESULTS: The INSR was expressed at the vessels surrounding tumor cells. Progression-free survival (PFS) was significantly shorter in the INSR-negative group than in the INSR-positive group. Multivariate analysis revealed that the INSR expression was the significantly independent predictor of PFS. In the specimens resected after VEGFR-TKI, the INSR expression was more frequently decreased. As the concentration of axitinib increased, the INSR expression in the HGEC was decreased. The tumors of PDX that were resected after demonstrating the resistance to axitinib had the decreased INSR expression. CONCLUSIONS: The decreased INSR expression could be correlated with the resistance to VEGFR-TKI and its expression may be useful in selecting appropriate drugs for advanced ccRCC patients. Source of Funding: None

MP45-17 GALECTIN-3 PLAYS CRITICAL ROLES FOR THE GROWTH OF BENIGN PROSTATIC HYPERPLASIA

INTRODUCTION AND OBJECTIVES: Galectin-3, a multifunctional oncogenic protein, has been reported to play important roles of progression in a variety of cancer including prostate cancer through the regulation of cancer cell proliferation, apoptosis, invasion and metastasis. However, we also identified the frequent up-regulation of Galectin-3 in benign prostatic hyperplasia (BPH), yet its pathophysiological roles in BPH. Here, we report the involvement of Galectin-3 in the growth of BPH. METHODS: To investigate the association of Galectin-3 expression and prostate volume, we examined serum Galectin-3 (pg/ ml) with ELISA method in non-cancer cohort and analyzed the correlation between Galectin-3 expression and prostate volume with Speamans correlation coefficient. Next, to analyzed proliferation abilities and the effect of Galectin-3 on smooth muscle, we examined knockdown of Galectin-3 expression by siRNA in BPH1 cells (benign prostatic hyperplasia cell line) and a co-culture experiment of BPH1 and PrSMC (Normal Human Prostate Smooth Muscle. Cells). Moreover, to investigate biological function of Galectin-3, we examined the gene expression profiles in Galectin-3-depleted BPH1 cells with microarray and bioinformatics analyses. RESULTS: Correlation analysis revealed that serum Galectin-3 (ng/ml) were correlated with prostate volume (R1⁄40.643 p1⁄40.023) (Figure 1). Next, depletion of Galectin-3 suppressed cell proliferation in BPH1 cells. Moreover, depletion of Galectin-3 in BPH1 cells suppressed cell proliferation of PrSMC cells in a co-culture method, suggesting Galectin-3 enhanced proliferation of PrSMC cells. Bioinformatics analysis with GSEA revealed that depletion of Galectin-3 was involved in interferon a response and interferon a response and interferon ? response (FDR q value < 0.001) (Figure 2), suggesting Galectin-3 regulates the proliferation of PrSMC through interferon response. CONCLUSIONS: Our findings suggest that Galectin-3 is significantly involved in the growth of BPH and a promising therapeutic target for patients with BPH. Source of Funding: GSK Japan Research Grant 2016