An Annotated Living Organoid Biobank for Studying Gallbladder Diseases and Drug Responses.

BACKGROUND

Gallbladder cancer (GBC) while rare worldwide has a high prevalence in India. Pathogenesis is unclear and outcomes poor. No suitable models are available to study GBC pathogenesis and drug response. The aim of this study was to establish a biobank comprising patient derived organoids (PDOs) from a wide variety of gallbladder diseases including GBC and other rare pathologies.

METHODS

PDOs were developed from surgically resected gallbladders 15 normal; 58 inflamed; 12 xanthogranulomatous cholecystitis (XGC); 5 pre-invasive neoplasm (PIN); and 13 invasive malignant gallbladder pathologies. Marker expressions, functional activity, histological and gene expression analyses were performed to validate the models. Banked PDOs were retrieved and drug assays performed to assess line-specific responses.

RESULTS

Protocol optimization achieved 58% (69/119) and 52% (10/19) success in organoid generation and expansion for all and invasive malignant pathologies, respectively-highest globally for GBC organoids reported to date. Organoids maintained tight junction integrity; P-gp pump and enzymatic activity; preserved tissue-specific gene and protein marker expression; histological features and genetic variations. Besides cryopreserved organoids from 62 patients, primary gallbladder tissue and high-quality DNA, RNA and protein derivatives have been banked. In gene expression analyses of tissue, XGC samples clustered with malignant subtypes, separate from benign pathologies. Derived XGC organoids showed a similar clustering. Enriched Hallmark pathways in XGC support neoplastic changes. Drug response assays demonstrate PDO line-specific response heterogeneity.

CONCLUSION

The developed biobank of PDOs from different gallbladder pathologies provides a promising resource to study gallbladder diseases, investigate the pathogenesis of GBC and study drug responses.