Isolation and phenotypic characterization of cancer stem cells from metastatic oral cancer cells

Objectives To isolate cancer stem cells (CSC) from a metastatic oral squamous cell carcinoma (OSCC) cell line and investigate their in vitro and in vivo phenotypic characteristics. Materials and Methods Subpopulations with individual staining intensities for CD44 and CD326 were isolated from the OSCC cell line LN‐1A by FACS: CD44 Low /CD326 − (CSC‐M 1 ), CD44 Low /CD326 High (CSC‐E), and CD44 High /CD326 − (CSC‐M 2 ). Proliferation, clonogenic potential, adhesion, migration, epithelial‐mesenchymal transition markers, and sensitivity to cisplatin and TVB‐3166 were analyzed in vitro. Tumor formation and metastasis were assessed by subcutaneous and orthotopic inoculations into BALB/c mice. Results E‐cadherin levels were higher in CSC‐E cells while vimentin and Slug more produced by CSC‐M 2 cells. CSC‐M 1 and CSC‐M 2 subpopulations showed higher proliferation, produced more colonies, and have stronger adhesion to the extracellular matrix. All cell lines established tumors; however, CSC‐E and CSC‐M 2 formed larger masses and produced more metastases. Conclusion The CSC subpopulations here described show increased cancer capabilities in vitro, tumorigenic and metastatic potential in vivo, and may be exploited in the search for novel therapeutic targets for OSCC.