Metastatic renal cell carcinoma (mRCC) is a tumor entity with poor prognosis due to limited therapy options. Tyrosine kinase inhibitors (TKIs), the novel targeted agents have been used for the treatment of mRCC and have shown efficacy. Interferon (IFN)-α is also one of the most frequently used agents in immunotherapy. However, drug resistance needs to be overcome to achieve a sufficiently positive effect. Interleukin-6 (IL-6), which induce suppressor of cytokine signaling-3 (SOCS3) expression, is one of the factors associated with poor prognosis of patients with renal cell carcinoma (RCC). To analyze the influence of IL-6 in drug resistance of RCC, anti-IL-6 receptor antibody was used in combination with IFN or TKIs. The SOCS3 mRNA expression level was significantly increased by IFNα stimulation in 786-O RCC cells which were resistant to IFN, but not in ACHN cells that were sensitive to IFN. The overexpression of SOCS3 by gene transfection in ACHN significantly inhibited the growthinhibitory effect of IFNα. An in vivo study demonstrated that coadministration of SOCS3-targeted siRNA promoted INFαinduced cell death and growth suppression in 786-O cell xenograft. SOCS3 could be a key component in the resistance to interferon treatment of renal cell carcinoma. Because SOCS3 is rapidly upregulated by IL-6 and a negative regulator of cytokine signaling, IL-6 expression on RCC cells was also analyzed and the 786-O cells showed the high level of IL-6 mRNA expression under the condition of interferon stimulation. IL-6R antibody, tocilizumab, significantly suppressed cell proliferation in 786-O cells by interferon stimulation accompanied with phosphorylation of STAT1 and inhibited SOCS3 expression. The in vivo effects of combination therapy with tocilizumab and interferon showed significant suppression of 786-O tumor growth in a xenograft model. We also hypothesized that TKI resistance and IL-6 secretion are causally connected. And we found that 786-O RCC cells secrete high IL-6 levels after low dose stimulation with the TKIs sorafenib, sunitinib and pazopanib, inducing activation of AKT-mTOR pathway, NFκB, HIF-2α and VEGF expression. Tocilizumab neutralizes the AKT-mTOR pathway activation and results in reduced proliferation. A combination therapy with tocilizumab and TKI suppresses 786-O tumor growth and inhibits angiogenesis in vivo more efficient than TKI alone. Our findings suggest that IL-6 could induce drug resistance on RCC, and combination therapy of IL-6R inhibitors and IFN/TKIs may represent a novel therapeutic approach for RCC treatment.

To identify the prevalence and predictors of postoperative detrusor underactivity during the early postoperative period after robot-assisted radical prostatectomy. Methods: We carried out a prospective observational study of 64 patients scheduled for robot-assisted radical prostatectomy using urodynamic study before and 1 month after robot-assisted radical prostatectomy. Detrusor underactivity was defined as maximum flow rate ≤15 mL/s and detrusor pressure at maximum flow rate ≤25 cmH 2 O during voiding. Incidences of pre-and postoperative detrusor underactivity were assessed, and predictors of postoperative detrusor underactivity were determined using uni-and multivariate logistic regression analyses. Factors comprised patient characteristics (age, prostate weight etc.), operative factors (surgical duration, nerve sparing etc.) and preoperative urodynamic study parameters (maximum flow rate, bladder contractile index etc.). Results: Pre-and postoperative detrusor underactivity at 1 month after robot-assisted radical prostatectomy were detected in one patient (1.6%) and 24 patients (37.5%), respectively. Univariate analysis selected preoperative maximum flow rate (P = 0.02), detrusor pressure at maximum flow rate (P = 0.04) and bladder contractile index (P < 0.01) as predictors of postoperative detrusor underactivity (odds ratio 0.83, 0.97 and 0.94, respectively). On multivariate analyses, only preoperative bladder contractile index was associated with postoperative detrusor underactivity (P < 0.01; odds ratio 0.94). A cut-off of 102.8 offered optimal accuracy in receiver operating characteristic analysis. Patient characteristics and operative factors were not significantly associated with postoperative detrusor underactivity. Conclusions: A comparatively high prevalence of postoperative detrusor underactivity is observed in patients at 1 month after robot-assisted radical prostatectomy. Patients with preoperative low bladder contractile index have a higher probability of developing early postoperative detrusor underactivity after robot-assisted radical prostatectomy.

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ObjectivesTo clarify the morphological change and characteristics of myofibroblast during the growth process of benign prostatic hyperplasia.MethodsThis study examined the characteristics of myofibroblasts during the growth process of the prostate in the stromal component‐dominant benign prostatic hyperplasia rat model. Transforming growth factor‐β1 and insulin‐like growth factor‐binding protein 3 expression were evaluated by western blotting (n = 6). We used double immunohistochemical staining to evaluate the number of myofibroblasts positive for α‐smooth muscle actin and vimentin in benign prostatic hyperplasia tissues. Expression and histological analyses of the benign prostatic hyperplasia were also carried out in rats at 2, 3 and 8 weeks after urogenital sinus implantation (n = 6). To evaluate the fine morphological characteristics of myofibroblasts in human benign prostatic hyperplasia tissues, electron microscopy analysis was additionally carried out.ResultsThere was a significant upregulation of the transforming growth factor‐β1 and insulin‐like growth factor‐binding protein 3 expression in benign prostatic hyperplasia (P < 0.05). There was a significant increase in the number of myofibroblasts in benign prostatic hyperplasia (P < 0.05) compared with normal prostate, with these abundantly located in the stromal area. The transforming growth factor‐β1 and insulin‐like growth factor‐binding protein 3 expression and number of myofibroblasts showed a time‐dependent increase (P < 0.05), with growth factor expressions preceding the myofibroblast increase. Electron microscopy confirmed that the myofibroblast progenitor cells, which possess abundant stress fibers, were predominantly located around fibrous areas in human benign prostatic hyperplasia.ConclusionsDifferentiation into myofibroblasts induced by transforming growth factor‐β1 and insulin‐like growth factor‐binding protein 3 actively occurs during the growth process of benign prostatic hyperplasia. Myofibroblast progenitor cells seem to be associated with prostatic fibrosis in human benign prostatic hyperplasia.

Background: To elucidate the pathogenesis of benign prostatic enlargement (BPE) in humans due to chronic inflammation caused by arteriosclerosis, the relationships between prostate size and the degree of chronic inflammation induced by local arteriosclerosis were investigated. Methods: The present cohort included 50 subjects who underwent robot-assisted radical prostatectomy (RARP) in a prospective study. The presence or absence of local arteriosclerosis in the prostatic arteries removed during RARP was evaluated by microscopic assessment. Chronic inflammation in the prostate was judged according to both the density and the extent of inflammatory cells. The expression of lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) and the infiltration of macrophages in the prostate, which are high in arteriosclerosis, were investigated by immunohistochemistry.Results: Local arteriosclerosis was observed in 28% (14/50). Prostate size and the inflammation score were significantly increased in the presence of arteriosclerosis (P = 0.006, P < 0.001, respectively). There was also a significant increase of LOX-1 in the epithelial and stromal cells of the prostate in the presence of arteriosclerosis (all, P < 0.001). Concerning the presence of macrophages, subjects with arteriosclerosis had significantly more positive expression of ionized calcium-binding adapter molecule-1 (IBA-1), a marker of macrophages, than subjects without arteriosclerosis (P < 0.001). Conclusions:In human surgical specimens, chronic inflammation owing to local arteriosclerosis of the prostatic arteries was significantly related to prostatic enlargement. Given the immunohistochemical analyses, the putative pathogenesis for this relationship is that LOX-1 induces macrophage infiltration, leading to BPE.

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BackgroundTumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a tumor-selective apoptosis inducer that is expressed in natural killer cells, whose cytotoxicity is activated by interferon (IFN). We investigated the effect of suppressor of cytokine signaling (SOCS) 3 on the expression of TRAIL receptors (DR4) and on TRAIL sensitivity in renal cell carcinoma (RCC) cells.MethodsVector expression, RNA interference and IL-6 receptor antibody tocilizumab were used to investigate the functional role of SOCS3 in DR4 expression. Immunoprecipitation was employed to detect the biochemical interaction between SOCS3 and DR4. The expression of DR4 induced by combination with IFN-α and tocilizumab was also examined by immunohistochemical staining using mice xenograft model.ResultsDR4 expression was up-regulated by IFN stimulation in RCC cells. 786-O cells were resistant to TRAIL and showed higher SOCS3 expression. ACHN cells showed higher DR4 expression and lower SOCS3 expression. Suppression of SOCS3 up-regulated DR4 expression and enhanced the TRAIL sensitivity in 786-O cells. In ACHN cells, DR4 expression was down-regulated by transfection with pCI-SOCS3, and the cells became resistant to TRAIL. Immunoprecipitation revealed the biochemical interaction between SOCS3 and DR4. A marked increase in IFN-induced DR4 protein expression after tocilizumab treatment was observed by immunohistochemical staining in the tumor from the mice xenograft model.ConclusionsOur results indicate that IFN and SOCS3 regulate DR4 expression in RCC cells. Combination therapy with IFN-α, tocilizumab and an anti-DR4 agonistic ligand appears to effectively inhibit advanced RCC cell growth.