Cancer Stem-like Cells Resist Chemo- and Radio- Therapy

Objectives: Cancer stem-like cells (CSCs) are assumed to be the seed cells of the tumor bulks, which in the cancer stem cell theory are hypothesized as the foundation of tumor genesis, development, relapse and metastasis. In this study, we explored the stemness features of cancer stem-like cells in two tongue squamous cancer cell (TSCC) lines (tca8113 and cal27) and their capacity of resisting the chemo- and radio- therapy.
Methods: After magnetic activated cell sorting (MACS), the sorted CSCs were characterized by cell proliferation and clonal formation assays in vitro and zenograft assay in vivo. Afterwards, the CSCs were respectively treated with three anti-tumor drugs (fluorouracil, cisplatin and vincristine) and radiation.
Results: It resulted that the sorted CSCs showed higher abilities in proliferation, clonal formation and oncogenesis, compared with the unsorted cancer cells. The survival rate of CSCs are higher than the unsorted cells under several anti-tumor approaches in vitro(P<0.05). Cancer drug-resistance and metabolism PCR Array revealed that there are significant differences in the expression of seven related genes between CSCs and the control group.
Conclusions: These results suggested that CSCs possess stronger resistance to the selected medications and radiation. The CSCs may be a potential target for TSCC treatment.