[P2-2-15] Phenotypic and morphological analyses of oral cancer spheroids in stromal organoid environment
Keywords:口腔癌スフェロイド、間質オルガノイド、口腔癌細胞株
Objectives: Oral cancer exhibits notorious invasiveness into surrounding tissues, but the invasiveness to muscles, bones, and peripheral nerves varies depending on each cancer cell properties. To clarify how the interaction with the extracellular matrix (ECM) affects characteristics of oral cancer cells, we performed spheroid and organoid cultures of established cell lines and evaluated their phenotypes by morphological and immunohistochemical analyses.
Materials & Methods: Oral cancer cell lines, HSC-2 and KOSC-2 (moderate differentiated), OSC-19 (poorly differentiated, high inducibility of vascular stroma) and OSC-20 (poorly differentiated, EMT-like traits), were cultured on low-attachment culture devices to form spheroids. Spheroids were further cultured within hydrogel mixture with immortalized-fibroblast as to be organoids. Resulting spheroids and organoids were subjected to immunostaining for two- and three-dimensional histological observation.
Results & Discussion: All cancer cell lines showed high proliferative activity, i.e., Ki-67-positive, in the spheroids. Similarly, all cells in the spheroids expressed E-cadherin and CD44vs, but the expression levels were weaker in poorly differentiated OSC-19 and OSC-20 than in moderately differentiated HSC-2 and KOSC-2. In organoid culture, HSC-2 and KOSC-2 showed a propensity to differentiate into prickle cells and exhibited distribution of Ki-67-positive cells, reminiscence of an epithelial tissue-like polarity. On the other hand, proliferative activity was maintained and cellular polarity was not eminent in OSC-19 and OSC-20 organoids. Instead, they showed an infiltration property such as pseudopod formation, presumably by an enhanced cell adhesion with its contact with ECM. These results suggested that changes in cancer cell phenotypes caused by cancer cell-ECM interactions also affected the formation of cell polarity and invasive/metastatic potential. Supported by JSPS KAKENHI Grant number 21K10053.
Materials & Methods: Oral cancer cell lines, HSC-2 and KOSC-2 (moderate differentiated), OSC-19 (poorly differentiated, high inducibility of vascular stroma) and OSC-20 (poorly differentiated, EMT-like traits), were cultured on low-attachment culture devices to form spheroids. Spheroids were further cultured within hydrogel mixture with immortalized-fibroblast as to be organoids. Resulting spheroids and organoids were subjected to immunostaining for two- and three-dimensional histological observation.
Results & Discussion: All cancer cell lines showed high proliferative activity, i.e., Ki-67-positive, in the spheroids. Similarly, all cells in the spheroids expressed E-cadherin and CD44vs, but the expression levels were weaker in poorly differentiated OSC-19 and OSC-20 than in moderately differentiated HSC-2 and KOSC-2. In organoid culture, HSC-2 and KOSC-2 showed a propensity to differentiate into prickle cells and exhibited distribution of Ki-67-positive cells, reminiscence of an epithelial tissue-like polarity. On the other hand, proliferative activity was maintained and cellular polarity was not eminent in OSC-19 and OSC-20 organoids. Instead, they showed an infiltration property such as pseudopod formation, presumably by an enhanced cell adhesion with its contact with ECM. These results suggested that changes in cancer cell phenotypes caused by cancer cell-ECM interactions also affected the formation of cell polarity and invasive/metastatic potential. Supported by JSPS KAKENHI Grant number 21K10053.