Kazuya Hanai

Development of bioartificial renal tubule devices with lifespan-extended human renal proximal tubular epithelial cells

BACKGROUND The bioartificial renal tubule device is a cell therapy system for renal failure. The major obstacle in the development of the bioartificial renal tubule device is the obtainment of a large number of viable renal tubule cells to seed on the inner surface of hollow fibers. Although our previous studies had used a transformed cell line, they may be dangerous for clinical uses. Therefore, different approaches to amplify renal proximal tubular epithelial cells (RPTEC) in culture without oncogenes, vectors and carcinogens have been required. METHODS The limitation of the replicative lifespan of human RPTEC, which is ∼12 population doublings (PDs), was extended by invalidating messenger RNA of cell cycle-related genes with antisense oligonucleotide or small interfering RNA (siRNA). RESULTS Periodic transfection of siRNA to a tumor suppressor p53 or a cyclin-dependent kinase inhibitor p16(INK4a) extended the lifespan by 33 and 63 PDs, respectively, in 3 months of culture. The siRNA-mediated lifespan extension was controllable because cell division ceased within 2 weeks after the transfection was discontinued. Expressions of γ-glutamyltransferase 1 and glucose transporter 1 were recovered in siRNA-transfected RPTEC cultured on porous membranes. Bioartificial renal tubule devices (0.8 m(2)) constructed with these cells showed reabsorption of water (122.3 ± 4.2 mL/30 min), sodium (18.1 ± 0.7 mEq/30 min) and glucose (121.7 ± 4.4 mg/30 min) after 1 week of circulation. Furthermore, β2-microglobulin and pentosidine were metabolized by RPTEC in mini-devices (65 cm(2)) within 48 h of circulation. CONCLUSIONS These approaches enabled us to yield a high enough number of RPTEC for construction of bioartificial renal tubule devices repeatedly. Lifespan-extended RPTEC could recover their specific characteristics by culturing on porous membranes, and bioartificial renal tubule devices constructed with these cells showed good performances of reabsorption and metabolism. SUMMARY A large number of human renal tubular cells required for construction of the bioartificial renal tubule device were prepared by extending the lifespan of the primary cells by invalidating mRNA of cell cycle-related genes. Constructed bioartificial renal tubule devices with lifespan-extended cells showed good performances of in vitro examination of reabsorption and metabolism. Requiring no oncogenes, vectors or cell cloning, the RNAi-mediated lifespan extension can help advance tissue-replacement therapy as well as basic research.

Laparoendoscopic single-site surgeries: A multicenter experience of 469 cases in Japan

To report on a multi‐institutional series of non‐robotic urological laparoendoscopic single‐site surgery in Japan.

Do metastatic upper tract urothelial carcinoma and bladder carcinoma have similar clinical responses to systemic chemotherapy? A Japanese multi-institutional experience

OBJECTIVE There has been no clear evidence supporting similar chemo-responses for upper and lower urothelial carcinomas. METHODS We conducted a multicenter retrospective cohort study to analyze urothelial carcinoma patients who underwent systemic chemotherapy at 17 centers from 2004 to 2010. A total of 298 patients with either urothelial carcinoma of the bladder (N = 151) or upper tract urothelial carcinoma (N = 147) were included. Differences in tumor location (urothelial carcinoma of the bladder vs. upper tract urothelial carcinoma) were evaluated in relation to the patient backgrounds and clinical responses to systemic chemotherapy. RESULTS Overall 216 patients were treated with cisplatin-based chemo-regimens (gemcitabine and cisplatin in 92, or methotrexate, vinblastine, adriamycin and cisplatin/methotrexate, epirubicin and cisplatin in 124). Among 186 initially metastatic patients, the incidences of lung metastasis and liver metastasis were 39.2 and 34.1%, respectively, in upper tract urothelial carcinoma patients, and were significantly higher than those with urothelial carcinoma of the bladder (22.4% for lung; 8.4% for liver metastasis). Among 112 post-surgical recurrent/metastatic patients, age was significantly higher and estimated glomerular filtration rate at baseline was significantly lower in upper tract urothelial carcinoma patients than those with urothelial carcinoma of the bladder. No significant differences were observed in overall clinical response rates for systemic chemotherapy between urothelial carcinoma of the bladder (45.8%) and upper tract urothelial carcinoma (38%) in initially metastatic patients or between urothelial carcinoma of the bladder (43.2%) and upper tract urothelial carcinoma (44.1%) in post-surgical recurrent/metastatic patients. Tumor location was not independently associated with cancer-specific survival in either initially metastatic or post-surgical recurrent/metastatic urothelial carcinoma patients. CONCLUSIONS No significant difference was observed in response rates of urothelial carcinoma of the bladder and upper tract urothelial carcinoma to systemic chemotherapy, suggesting that a similar chemo-regimen can be applied to metastatic urothelial carcinoma patients regardless of tumor location (upper vs. lower).

Total pelvic floor reconstruction during non‐nerve‐sparing laparoscopic radical prostatectomy: Impact on early recovery of urinary continence

To develop a modified technique of “total pelvic floor reconstruction” during non‐nerve‐sparing laparoscopic radical prostatectomy, and to determine its effect on postoperative urinary outcomes.

Dorsal vein complex preserving technique for intrafascial nerve-sparing laparoscopic radical prostatectomy

To describe a novel dorsal vein complex preserving technique for intrafascial nerve‐sparing laparoscopic radical prostatectomy and to evaluate its postoperative outcomes.

A 2-week Maintenance Regimen of Intravesical Instillation of Bacillus Calmette–Guérin is Safe, Adherent and Effective in Patients with Non-Muscle-Invasive Bladder Cancer: A Prospective, Multicenter Phase II Clinical Trial

OBJECTIVE To investigate the safety and efficacy of a maintenance regimen of bacillus Calmette-Guérin therapy including 6-week induction and 2-week maintenance instillation for patients with recurrent or multiple Ta, T1 tumors or carcinoma in situ of the urinary bladder. METHODS This study was performed as single-arm multi-institutional study. The enrolled patients had been diagnosed with urothelial carcinoma of the bladder, including the presence of at least two bladder tumors, single tumors recurring within 12 months of follow-up, any Grade 3 Stage Ta or T1 tumor, and primary or recurrent biopsy proven carcinoma in situ. Patients received 81 mg intravesical bacillus Calmette-Guérin (Connaught strain). The instillation was repeated once a week for another 5 weeks, followed by once a week for 2 weeks at months 3, 6, 12, 18, 24, 30 and 36, for a total of 20 instillations in 3 years. RESULTS From 28 hospitals, 202 patients were registered. A total of 186 patients matched the inclusion criteria: 139 patients in the Ta/T1group and 47 patients in the carcinoma in situ group. At the 4-year median point of follow-up, recurrence-free survival rates in the Ta/T1 group and the carcinoma in situ group were 76.7 and 77.7%, respectively. Completion rates for maintenance therapy in both groups at months 3, 6, 12, 24 and 36 were 81.7, 68.9, 58.1, 42.5 and 35.0%, respectively. Common toxicities were pain on urination, urinary frequency and gross hematuria. There was no treatment-related death. CONCLUSIONS This regimen may be feasible in patients with Ta/T1 tumor or carcinoma in situ; however, future Phase III randomized study is needed to determine whether this regimen would be truly safe and effective compared with 3-week maintenance regimen.