Naokazu Ibuki

Superagonistic CD28 Antibody Induces Donor-Specific Tolerance in Rat Renal Allografts

The ultimate goal of organ transplantation is to establish graft tolerance where CD4+CD25+FOXP3+ regulatory T (Treg) cells play an important role. We examined whether a superagonistic monoclonal antibody specific for CD28 (CD28 SA), which expands Treg cells in vivo, would prevent acute rejection and induce tolerance using our established rat acute renal allograft model (Wistar to Lewis). In the untreated or mouse IgG‐treated recipients, graft function significantly deteriorated with marked destruction of renal tissue, and all rats died by 13 days with severe azotemia. In contrast, 90% of recipients treated with CD28 SA survived over 100 days, and 70% survived with well‐preserved graft function until graft recovery at 180 days. Analysis by flow cytometry and immunohistochemistry demonstrated that CD28 SA induced marked infiltration of FOXP3+ Treg cells into the allografts. Furthermore, these long‐surviving recipients showed donor‐specific tolerance, accepting secondary (donor‐matched) Wistar cardiac allografts, but acutely rejecting third‐party BN allografts. We further demonstrated that adoptive transfer of CD4+CD25+ Treg cells, purified from CD28 SA‐treated Lewis rats, significantly prolonged allograft survival and succeeded in inducing donor‐specific tolerance. In conclusion, CD28 SA treatment successfully induces donor‐specific tolerance with the involvement of Treg cells, and thus the therapeutic value of this approach warrants further investigation and preclinical studies.

Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis.

Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferation of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa.

Total Cystectomy Versus Bladder Preservation Therapy for Locally Invasive Bladder Cancer: Effect of Combined Therapy Using Balloon-occluded Arterial Infusion of Anticancer Agent and Hemodialysis With Concurrent Radiation

Objectives:We tested the usefulness of balloon-occluded arterial infusion (BOAI) of anticancer agent (cisplatin/gemcitabine), concomitant with hemodialysis, which delivers an extremely high concentration of anticancer agent to the site of a tumor without systemic adverse effects, along with concurrent radiation [Osaka-Medical College (OMC)-regimen] in patients with locally advanced bladder cancer. The results were compared with those of cystectomy. Methods:One hundred twenty-four patients were assigned to receive cystectomy (Gp1, n = 62) or OMC-regimen (Gp2, n = 62). In Gp2, patients besides undergoing complete response subsequently received secondary-BOAI with gemcitabine (1600 mg). Results:In Gp1, 27 of 62 patients (43.5%) suffered disease recurrence, and more than half died within 1 year; the remainder died thereafter. The overall 5-, 10-, and 15-year survival rates were 53.8%, 46.0%, and 40.0%, respectively. In contrast, in Gp2, >70% of patients (44 of 62), especially >95% of patients with locally invasive tumors achieved complete response with no evidence of recurrent disease or metastasis after a mean follow-up of 163 (range, 32–736) weeks. At 14 years, overall survival was significantly improved at 79.7% (P = 0.015 vs. Gp1). Moreover, salvage therapy for secondary-BOAI with gemcitabine was effective in all 3 patients with T4 tumors or lymph node involvement, who showed stable disease (SD) after primary therapy with CDDP. No patients suffered Grade III or more severe toxicities. Conclusion:OMC-regimen, a new strategy for patients with locally-invasive bladder cancer, can be curative not only in patients for whom cystectomy is indicated, but also in patients whose condition is not amenable to curative treatment and for whom merely palliative treatment would otherwise seem the only option.

Current treatment strategies for advanced prostate cancer

During the past decade, treatment strategies for patients with advanced prostate cancer involving stage IV (T4N0M0, N1M0 or M1) hormone‐sensitive prostate cancer and recurrent prostate cancer after treatment with curative intent, as well as castration‐resistant prostate cancer, have extensively evolved with the introduction and approval of several new agents including sipuleucel‐T, radium‐223, abiraterone, enzalutamide and cabazitaxel, all of which have shown significant improvement on overall survival. The appropriate use of these agents and the proper sequencing of these agents are still not optimized. The results of several recently reported randomized controlled trials and retrospective studies could assist in developing a treatment strategy for advanced prostate cancer. In addition, prospective studies and molecular characterization of tumors to address these issues are ongoing.

The influence of growth hormone/insulin-like growth factor deficiency on prostatic dysplasia in pbARR2-Cre, PTEN knockout mice

Background:Elevated insulin-like growth factor-I (IGF-I) serum levels and phosphatase and tensin homolog (PTEN) loss are prostate cancer (PCa) risk factors that enhance androgen-responsive and castration-resistant PCa xenografts growth.Methods:The impact of suppressed growth hormone (GH)/IGF-I levels on neoplastic initiation of PTEN-deficient prostate epithelia was assessed histologically and by epithelial-to-mesenchymal marker expression in Ghrhr D60G homozygous (lit/lit) and heterozygous (lit/+) pbARR2-Cre, PTEN(fl/fl) (PTEN−/−) mice. How suppressed GH/IGF-I levels impacted growth of PTEN−/− mouse-derived prostate cells (MPPK) was examined by growth and survival signaling of cells cultured in lit/+ or lit/lit serum.Results:Body weight, prostate weight and serum GH and IGF-I levels were reduced in lit/lit relative to lit/+ PTEN−/− littermates. While the anterior lobes of lit/+ PTEN−/− prostates consistently presented swollen, indicative of ductal blockage, the degree of prostatic dysplasia in 15- and 20-week-old lit/lit and lit/+ PTEN−/− mice was indistinguishable as measured by normalized prostatic weight, tissue histology, or probasin, PSP94, E-cadherin, N-cadherin and vimentin expression. However, growth and AKT activation of MPPK cells was decreased when cultured in lit/lit serum as compared with lit/+ serum and restored in lit/lit serum supplemented with IGF-I and, to a lesser extent, GH.Conclusions:These results suggest that initiation of prostate carcinogenesis by loss of PTEN is not influenced by germline variation of genes encoding signaling molecules in the GH/IGF-I axis, but suggests that these factors may affect the progression of dysplastic phenotype and supports previous studies, indicating that the GH/IGF milieu does impact the growth of PTEN-deficient dysplastic prostatic cells once transformed.

Novel Bladder Preservation Therapy with Osaka Medical College Regimen

PURPOSE We investigated the effect of balloon occluded arterial infusion of an anticancer agent (cisplatin/gemcitabine), used concomitantly with hemodialysis, which delivers an extremely high concentration of anticancer agent to the tumor site without systemic adverse effects, along with concurrent radiation (referred to as the Osaka Medical College regimen) in patients with advanced bladder cancer. MATERIALS AND METHODS A total of 329 patients (TisN0 16, T2N0 174, T3N0 77, T4N0 22 and TxN+ 40) were assigned to receive the Osaka Medical College regimen. Patients who did not achieve complete response underwent total cystectomy or secondary balloon occluded arterial infusion with an increased amount of cisplatin and/or gemcitabine. RESULTS The Osaka Medical College regimen allowed 83.6% (276 of 329) of patients in total and 93.6% (250 of 267) of patients with organ confined disease (including T3b) to achieve complete response. Of the patients with a complete response 96% (240 of 250) survived with a functional bladder without evidence of recurrent disease within a mean followup of 159 weeks. Although lymph node involvement, especially N2 stage, was selected as a significant risk factor for treatment failure and survival, it was noteworthy that 61.9% of patients with N1 disease achieved complete response and that the 5-year overall survival rate was 72.2%. No patients had grade III or more severe toxicities. CONCLUSIONS The Osaka Medical College regimen, a new bladder preservation strategy, can be curative not only in patients for whom cystectomy is indicated, but also in patients whose condition is not amenable to curative treatment because of disease stage, age or other factors, and for whom merely palliative therapy would otherwise seem the only option.

Neoadjuvant and adjuvant chemotherapy for locally advanced bladder carcinoma: Development of novel bladder preservation approach, Osaka Medical College regimen

Cisplatin‐based chemotherapy has been widely used in a neoadjuvant as well as adjuvant setting. Furthermore, trimodal approaches including complete transurethral resection of the bladder tumor followed by combined chemotherapy and radiation have generally been performed as bladder preservation therapy. However, none of the protocols have achieved a 5‐year survival rate of more than 70%. Additionally, the toxicity of chemotherapy and/or a decreased quality of life due to urinary diversion cannot be ignored, as most patients with bladder cancer are elderly. We therefore newly developed the novel trimodal approach of “combined therapy using balloon‐occluded arterial infusion of anticancer agent and hemodialysis with concurrent radiation, which delivers an extremely high concentration of anticancer agent to the site of a tumor without systemic adverse effects (“Osaka Medical College regimen” referred to as the OMC regimen). We initially applied the OMC regimen as neoadjuvant chemotherapy for locally advanced bladder cancer. However, since more than 85% of patients with histologically‐proven urothelial cancer achieved complete response with no evidence of recurrence after a mean follow‐up of 170 (range 21–814) weeks, we have been applying the OMC‐regimen as a new approach for bladder sparing therapy. We summarize the advantage and/or disadvantage of chemotherapy in neoadjuvant as well as adjuvant settings, and show the details of our newly developed bladder sparing approach OMC regimen in this review.

Induction of donor-specific tolerance using superagonistic CD28 antibody in rat renal allografts: regulatory T-cell expansion before engraftment may be important.

Background. We hypothesized that a superagonistic monoclonal antibody specific for CD28 (CD28SA), which expands regulatory T cells (Tregs) in vivo, would prevent acute rejection and prolong the survival of renal allograft. Methods. We examined whether CD28SA treatment induce donor-specific tolerance using our established rat renal allograft model (Wistar-Lewis). Results. All control rats died within 13 days because of severe azotemia with marked destruction of graft tissue. In contrast, recipients treated with a triple injection of CD28SA (days −3, 0, and 3) showed good preservation of graft histology and function, with considerable infiltration of Tregs into the allografts; 92% of recipients survived for more than 100 days, and 77% survived by the day of harvest at 180 days. These long-surviving recipients received secondary heterotopic bicardiac allografts from both donor-matched Wistar and third-party Brown Norway rats simultaneously 120 days after kidney transplantation, and seven of eight (87.5%) rats exhibited donor-specific tolerance, accepting the Wistar heart, but acutely rejecting the Brown Norway heart. Interestingly, a single injection of CD28SA 3 days before (day −3), but not 3 days after (day 3), transplantation also induced donor-specific tolerance in some recipients. We then performed adoptive transfer of nonspecific CD4+CD25+ Tregs, purified from CD28SA-treated Lewis rats, with simultaneous injection of hepatocyte growth factor (500 &mgr;g/kg/day, intravenously). The treatment induced significant prolongation of graft survival (P<0.0001 vs. control group), and five of eight (62.5%) recipients survived until the day of harvest at 180 days with successful induction of donor-specific tolerance. Conclusions. We have established a novel therapeutic approach for inducing donor-specific tolerance in rats with renal allografts.

The systemic inflammation-based Glasgow Prognostic Score as a powerful prognostic factor in patients with upper tract urothelial carcinoma

Introduction and Objective The combination of C-reactive protein and albumin, the Glasgow Prognostic Score (GPS), had independent prognostic value in patients with varying cancers, except for upper tract urothelial carcinoma (UTUC). The aim of this study was to describe the relationship between GPS and survival in patients with UTUC after adjustment for other prognostic factors. Materials and Methods We queried 2 UTUC databases. Retrospective clinical series on patients with localized UTUC managed by nephroureterectomy with bladder cuff, for whom data from the Yamaguchi Uro-Oncology Group and Osaka Medical College registry, including age, presence of bladder cancer, pT stage, lymphovascular invasion, C-reactive protein (CRP) and albumin, were analyzed. The GPS was constructed by combining CRP and albumin. Cancer specific survival (CSS) and overall survival (OS) and relative excess risk of death were estimated by GPS categories after adjusting for gender, age, ECOG performance status (PS), grade, and lymphovascular invasion (LVI). Results Seven hundred and twenty four UTUC patients were identified. Our final cohort included 574 patients; of these, 29.2% died during a maximum follow up of 16.7 years. The estimated mean 10-year CSS of patients with GPS of scre-0, -1, and -2 was 99.5, 95.1, and 75.9 months, respectively. Patients with GPS of score-2 had poorest 10-year estimated mean OS of 67.6 months (57.2–77.9). Raised GPS also had a significant association with excess risk of cancer death at 10 years (GPS 2: Relative Excess Risk = 1.74, 95% CI 1.20–2.54) after adjusting for gender, patients’ age, ECOG PS, and tumor focality. C-index of GPS both for CSS and OS were superior to patients’ age and tumor focality, and comparable to grade. Conclusions The GPS is an independent prognostic factor for CSS and OS after surgery with curative intent for localized UTUC. It significantly increases the accuracy of established prognostic factors. The GPS may provide a meaningful adjunct for patient counseling and clinical trial design.

The Anti-Proliferative Effect of Boron Neutron Capture Therapy in a Prostate Cancer Xenograft Model

Purpose Boron neutron capture therapy (BNCT) is a selective radiation treatment for tumors that preferentially accumulate drugs carrying the stable boron isotope, 10B. BNCT has been evaluated clinically as an alternative to conventional radiation therapy for the treatment of brain tumors, and more recently, recurrent advanced head and neck cancer. Here we investigated the effect of BNCT on prostate cancer (PCa) using an in vivo mouse xenograft model that we have developed. Materials and Methods Mice bearing the xenotransplanted androgen-independent human PCa cell line, PC3, were divided into four groups: Group 1: untreated controls; Group 2: Boronophenylalanine (BPA); Group 3: neutron; Group 4: BPA-mediated BNCT. We compared xenograft growth among these groups, and the body weight and any motility disturbance were recorded. Immunohistochemical (IHC) studies of the proliferation marker, Ki-67, and TUNEL staining were performed 9 weeks after treatment. Results The in vivo studies demonstrated that BPA-mediated BNCT significantly delayed tumor growth in comparison with the other groups, without any severe adverse events. There was a significant difference in the rate of freedom from gait abnormalities between the BPA-mediated BNCT group and the other groups. The IHC studies revealed that BNCT treatment significantly reduced the number of Ki-67-positive cells in comparison with the controls (mean±SD 6.9±1.5 vs 12.7±4.0, p<0.05), while there was no difference in the number of apoptotic cells, suggesting that BPA-mediated BNCT reduced PCa progression without affecting apoptosis at 9 weeks post-treatment. Conclusions This study has provided the first preclinical proof-of-principle data to indicate that BPA-mediated BNCT reduces the in vivo growth of PCa. Although further studies will be necessary, BNCT might be a novel potential treatment for PCa.