[Establishment of patient-derived salivary gland basal cell adenoma organoids]

Objective: To establish an in vitro organoid model of human salivary gland basal cell adenoma (BCA). Methods: Fresh tumor sample from a 66-year-old female patient diagnosed with salivary gland BCA was collected from the Dpartment of Oral pathology, Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine in October 2021. And the organoid culture was performed in vitro in a culture medium based on solid droplets of matrix gel, and the growth of the organoid was observed by inverted microscopy. After 14 days, the organoid was fixed in 10% neutral formalin and made into paraffin blocks by agar pre-embedding paraffin embedding method, sectioned. HE staining, morphological observation and immunohistochemical staining of p63, Ki-67, cytokeratin14 (CK14), β-catenin, S-100 and calponin were used for organoids identification. Results: The established BCA organoids were lobulated nodular locally under light microscopy, with deposition of eosinophilic glass-like material around the nests of organoid cells, similar to the morphological architectures of the parental BCA. Immunohistochemistry showed that organoids expressed CK14, p63, and β-catenin in various degree, which was consistent with the immunophenotypic characteristics of the parental BCA tumor cells. Conclusions: An in vitro culture system of BCA organoids was preliminarily established which provides a new model for the study of the pathogenesis of salivary gland tumors.