Combining microfluidic chip and low-attachment culture devices to isolate oral cancer stem cells

Background/purpose: Cancer stem cells (CSCs) are widely recognized as key drivers of cancer initiation, progression, and therapeutic resistance. Microfluidic chip technology offers a promising approach for CSC isolation and study. This study investigated the efficacy of a microfluidic chip-based method for isolating single cells from oral cancer cell lines characterized by high stem-like phenotypes. Specifically, the study focused on examining the sphereforming capability and the expression of CSC markers, including aldehyde dehydrogenase 1A1 (ALDH1A1), CD44, and CD133, in isolated cell clones from OECM-1 and SAS cell lines. Materials and methods: Oral cancer cell lines were subjected to isolation using a microfluidic chip. The captured single cells were cultured to assess their sphere-forming capacity in ultralow binding culture. Furthermore, the protein expression levels of ALDH1A1, CD44, and CD133 in the isolated cell clones were analyzed using western blotting. Results: The microfluidic chip-assisted isolation method significantly enhanced the sphereforming capability of both OECM-1 and SAS cell clones compared to their parent cell lines. Moreover, the expression levels of CSC markers ALDH1A1, CD44, and CD133 were upregulated in the microfluidic chip-assisted isolated cell clones, indicating a higher stem-like phenotype. Conclusion: This study demonstrates the effectiveness of the microfluidic chip-based approach in isolating oral cancer cell clones with elevated stem-like characteristics. This method offers a valuable tool for further investigation of CSCs and their role in cancer progression, as well as future therapy development for oral cancers. (c) 2023 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY -NC -ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).