Background & aims: Oropharyngeal and esophageal squamous cell carcinomas, especially the latter, are a lethal disease, featuring intratumoral cancer cell heterogeneity and therapy resistance. To facilitate cancer therapy in personalized medicine, three-dimensional (3D) organoids may be useful for functional characterization of cancer cells ex vivo. We investigated the feasibility and the utility of patient-derived 3D organoids of esophageal and oropharyngeal squamous cell carcinomas.
Methods: We generated 3D organoids from paired biopsies representing tumors and adjacent normal mucosa from therapy-naïve patients and cell lines. We evaluated growth and structures of 3D organoids treated with 5-fluorouracil ex vivo.
Results: Tumor-derived 3D organoids were grown successfully from 15 out of 21 patients (71.4%) and passaged with recapitulation of the histopathology of the original tumors. Successful formation of tumor-derived 3D organoids was associated significantly with poor response to presurgical neoadjuvant chemotherapy or chemoradiation therapy in informative patients (P = 0.0357, progressive and stable diseases, n = 10 vs. partial response, n = 6). The 3D organoid formation capability and 5-fluorouracil resistance were accounted for by cancer cells with high CD44 expression and autophagy, respectively. Such cancer cells were found to be enriched in patient-derived 3D organoids surviving 5-fluorouracil treatment.
Conclusions: The single cell-based 3D organoid system may serve as a highly efficient platform to explore cancer therapeutics and therapy resistance mechanisms in conjunction with morphological and functional assays with implications for translation in personalized medicine.
Keywords: 3D Organoids; 3D, 3-dimensional; 5-Fluorouracil; 5FU, 5-fluorouracil; AV, autophagy vesicle; Autophagy; CD44; CD44H, high expression of CD44; CQ, chloroquine; DMEM, Dulbecco’s modified Eagle medium; EMT, epithelial-mesenchymal transition; ESCC, esophageal squamous cell carcinoma; FBS, fetal bovine serum; H&E, hematoxylin and eosin; IC50, half maximal inhibitory concentration; IHC, immunohistochemistry; LC3, light chain 3; OPSCC, oropharyngeal squamous cell carcinoma; PI, propidium iodide; SCCs, squamous cell carcinomas; TE11R, 5-fluorouracil–resistant derivative of TE11.