Development of patient-derived tumor organoids and a drug testing model for renal cell carcinoma

The selection of effective therapeutic agents is critical for improving the survival of patients with renal cell carcinoma (RCC). The aim of the present study was to develop an ex vivo drug testing assay using patient-derived tumor organoid (TO) cultures. For this purpose, surgical tumor specimens were obtained from 20 patients with RCC. TOs were developed ex vivo from freshly resected RCC tumors, and their histopathological and molecular characteristics were evaluated using histological staining and whole-exome sequencing (WES). Using a cell viability assay, the therapeutic efficacy of standard of care tyrosine kinase inhibitors in RCC TOs was determined. It was found that TOs recapitulated the histological features of primary RCC tumors. Using WES, a strong concordance was identified at the genetic level between the primary tumors and their corresponding TOs. Using patient-derived TO models, a prototype of an ex vivo drug testing assay was developed, and it was found that RCC TOs exhibited differential responses to sunitinib, pazopanib, cabozantinib, axitinib and sorafenib treatment. On the whole, although the predictive value of the current assay has to be tested and validated in future clinical studies, the findings of the present study demonstrate a novel approach for ex vivo drug testing in patient-derived TO models, which may have potential for use in the personalized treatment of cancer patients.