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Biomedical subjects

Yuki Kita

Publications and source records attributed to Yuki Kita.

2 recordsLinked to original sources

Clinical Validation of a Multiplex Urine Biomarker Assay for Surveillance of Recurrent Bladder Cancer.

PURPOSE: More than 50% of patients with non-muscle-invasive bladder cancer experience recurrence, requiring lifelong surveillance with repeated cystoscopy. Given the invasive nature and cost of cystoscopy, accurate noninvasive tools are needed to support risk-adapted monitoring. We evaluated the ability of Oncuria-Monitor, a multiplex urine biomarker assay, to detect recurrent bladder cancer during surveillance. PATIENTS AND METHODS: Between February 2017 and August 2020, six medical centers in the United States and Japan prospectively enrolled 300 patients with a history of bladder cancer, generating 1,248 serial urine samples. Participants were divided into training and validation cohorts. At each surveillance visit over 2 years, urine samples were analyzed in a blinded manner using Oncuria-Monitor and BladderChek, alongside urine cytology. Test performance was compared with cystoscopy and histopathology-confirmed recurrence. RESULTS: Recurrent bladder cancer was identified in 31% (93/300) of participants, with 143 total recurrences during follow-up, including 90 tumors in the validation cohort. In the validation cohort, Oncuria-Monitor achieved a sensitivity of 85.6% [95% confidence interval (CI), 78.1%-92.2%] and a negative predictive value (NPV) of 93% (95% CI, 89.2%-96.4%). In comparison, BladderChek demonstrated a sensitivity of 20.0% and an NPV of 88%, whereas urine cytology showed a sensitivity of 36.9% and an NPV of 91.6%. The number needed to evaluate to detect one recurrence was 3 for both cystoscopy and Oncuria-Monitor, compared with 15 for BladderChek and 8 for cytology. CONCLUSIONS: In this large prospective longitudinal study, Oncuria-Monitor demonstrated clinically actionable performance, enabling a rule-out strategy that could safely reduce cystoscopy in approximately 25% of surveillance visits. These findings support a paradigm shift toward biomarker-guided, risk-adapted surveillance in bladder cancer that reduces unnecessary invasive procedures while maintaining oncologic safety.

Humans

Establishment and Characterization of Patient-Derived Xenograft Organoids for Personalized Treatment of Castration-Resistant Prostate Cancer.

BACKGROUND: Basic research on castration-resistant prostate cancer (CRPC) is limited by the lack of clinically relevant models. This study aimed to establish patient-derived xenografts (PDX) and PDX-derived organoids from clinical CRPC specimens to develop a bidirectional experimental platform for in vivo xenografts and ex vivo organoids. METHODS: We established a new PDX library (KUCaP PDX series) using CRPC clinical specimens and derived prostate cancer organoids. Comprehensive biological characterization of clinical specimens, PDXs, PDX-derived organoids, and organoid-derived xenografts (ODXs) was performed to confirm the preservation of the original tumor features. Using our PDX library, we conducted genetic engineering and drug testing to explore novel therapeutic approaches. RESULTS: PDX-derived organoids were successfully established from all eight KUCaP PDX lines (100%). Four of the eight lines (50%) were maintained during the long-term culture experiments for over ten passages. Key features observed in the original clinical specimens, including genetic alterations and castration responsiveness, were maintained across the PDX, PDX-derived organoid, and ODX models. RNA sequencing revealed that transcriptomic profiles were consistently maintained across clinical specimens, PDXs, PDX-derived organoids, and ODXs. One PDX and organoid (KUCaP19) which exhibited a high homologous recombination deficiency (HRD) score, without any pathogenic homologous recombination repair (HRR) gene alterations, showed sensitivity to a poly ADP-ribose polymerase (PARP) inhibitor. In contrast, KUCaP12, which had no HRR alterations and a low HRD score, did not respond to PARP inhibition. CONCLUSIONS: We developed the KUCaP library as a novel experimental platform for CRPC research by integrating clinical specimens with PDX, organoid, and ODX models along with their genomic and transcriptomic data. These models largely retained the genetic profiles and responses to castration observed in the original tumors. The bidirectional use of personalized PDX and organoids will facilitate the elucidation of the molecular mechanisms of CRPC.

Male