Biology subjects

Woodward, A. P.

Publications and source records attributed to Woodward, A. P..

3 recordsLinked to original sources

bioRxiv2025

Establishing a Canine Urothelial Organoid Repository: A Platform for Comparative and Translational Carcinoma Studies

Despite the increasing number of treatment options for patients with muscle-invasive bladder Cancer (MIBC), many of these patients ultimately have a poor prognosis. Drug responses vary considerably among patients and in many who respond initially, drug resistance may ultimately develop leading to tumor progression. Scope for improvement has been limited by the phenotypic and molecular diversity of MIBC, which impacts the selection pressures of therapy. To address this translational gap, we describe the largest known canine urothelial carcinoma organoid bioarchive, with in-depth phenotypical and molecular characterization. Immunohistochemistry confirmed the expression of key biomarkers including UPKIII, E-cadherin, Vimentin, and Ki-67 in organoids. Single-nucleus RNA sequencing revealed cellular heterogeneity, while bulk RNA sequencing showed canine patient-to-patient variability in transcriptomic profiling. Bulk RNA sequencing also displayed highly similar expression profiles between tissue- and urine-derived organoids, as well as similarity to previously published human MIBC transcriptome data. Whole genome sequencing in a subset of patients further supported the overall genomic fidelity of the organoids with their tissue of origin. Finally, for proof-of-concept of usefulness for drug testing studies, organoid cytotoxicity to vinblastine was investigated in several organoid lines. These canine bladder cancer organoid lines can be thawed, expanded, and screened for response to potential novel therapeutics to expand personalized medicine approaches. In addition, the organoid lines can serve as a valuable resource for comparative bladder cancer research, and as a pre-clinical screening tool to identify efficacious drugs before taking them into canine clinical trials to support future human clinical trials.

cancer biology↗

bioRxiv2025

Frequency and Characterization of Rare Histologic Subtypes in Canine Invasive Urothelial Carcinoma

The histologic and molecular heterogeneity of human muscle-invasive bladder cancer (MIBC) is a major contributor to poor treatment outcomes. While most cases of MIBC are diagnosed as conventional urothelial carcinoma (UC), there is growing recognition of histologic subtypes and divergent differentiation within conventional UC. This is clinically significant, as some require modification of therapy and some are associated with more aggressive behavior. Spontaneously occurring UC in dogs has been shown to exhibit histologic and molecular features that closely resemble those of human MIBC. In this study, we evaluated 31 canine UC tumor samples for histologic subtypes and divergent differentiation. Slides were reviewed by a human uropathologist and three board-certified veterinary pathologists and assessed for expression of uroplakin III and E-cadherin. All tumors were classified as high-grade UC. Fifteen cases were identified as conventional UC. Among the remainder, eight displayed glandular differentiation, four were classified as sarcomatoid UC, two showed squamous differentiation, and one case each was classified as large nested and tubular and microcystic subtypes. In summary, this study found a higher frequency of certain histologic subtypes and divergent differentiation in canine UC--particularly sarcomatoid UC and UC with glandular differentiation--compared to previous reports in both canine UC and human MIBC. ConclusionThe relatively high prevalence of the sarcomatoid UC subtype in dogs observed in this study suggests that canine UC may serve as a valuable translational model for evaluating novel therapeutic agents, particularly for this rare and aggressive variant in humans.

pathology↗

bioRxiv2023

Applying Hierarchical Generalized Additive Models to Non-Compartmental Analysis of Pharmacokinetic Data

Non-compartmental analysis (NCA) is a popular strategy for obtaining estimates of pharmacokinetic parameters, while requiring both minimal structural assumptions, and limited input by the analyst. As typically applied, its scope and depth are constrained by its statistical simplicity. Embedding the NCA within a hierarchical generalized additive model (HGAM) may facilitate the simultaneous analysis of data from multiple subjects, estimation of covariate effects in one stage, and implementation of censored responses, similarly to the capabilities of nonlinear multilevel models as widely applied in pharmacometrics. HGAM is an interesting extension to multilevel linear models that allows the effects of predictors to be implemented as smooth functions, which has been widely implemented in various disciplines to nonlinear trends, including for longitudinal data. This approach extends the capability of previous implementations of spline-based methods applied to NCA, within an accessible workflow in open software. Application of HGAM to two example datasets, one describing oral drug administration, and one describing IV and oral drug administration with categorical covariates and censoring, illustrates the overall approach, including parameter estimation, visualization and model checking, and uncertainty quantification. A Bayesian approach to estimation facilitates interpretable expressions of the uncertainty in individual parameters, population parameters, and functions of parameters such as contrasts.

pharmacology and toxicology↗