Establishment and Functional Characterization of Patient-Derived Organoids from Colorectal Adenocarcinoma and Oral Squamous Cell Carcinoma

Patient-derived organoids have emerged as valuable platforms for modeling tumor biology and evaluating therapeutic responses. However, their application in squamous cell carcinomas remains limited. Therefore, in this study, organoid cultures were established from patients with colorectal adenocarcinoma and oral squamous cell carcinoma using a standardized protocol, and their biological and functional characteristics were evaluated. Tumor specimens were obtained from five patients with colorectal adenocarcinoma and two patients with oral squamous cell carcinoma. Organoids were successfully established in four of five colorectal cancer cases (80%) and in one of two oral squamous cell carcinoma cases (50%). The established organoids preserved key histological and immunophenotypic features of the parental tumors, and xenograft experiments confirmed in vivo tumorigenicity and the maintenance of tumor morphology. Moreover, whole genome sequencing of a colorectal cancer-derived organoid revealed chromosomal instability and pathogenic alterations in APC, NRAS (p.Q61H), and TP53. Furthermore, drug sensitivity screening identified distinct response profiles among organoid lines. Overall, this study demonstrated that organoids can be established from both adenocarcinomas and squamous cell carcinomas using a simple common protocol. Moreover, a rare NRAS Q61-mutant colorectal cancer organoid was established. This provides a valuable model for biological studies and therapeutic development of NRAS-mutant colorectal cancer.