Abstract:

Objective To detect the expression of aldehyde dehydrogenase（ALDH） in tongue squamous cell carcinoma Tca8113 cell line and observe the biological characteristics of tumor cells expressing high level of ALDH （ALDHhig）. Methods The expression of ALDH in tongue squamous cell carcinoma Tca8113 cell line was detected by the flow cytometry. The ALDHhig and ALDHlow subpopulation cells were isolated and cultured in vitro respectively. The ability of differentiation, proliferation and tumorsphere formation were detected. Suppression subtractive hybridization（ SSH） was employed to screen the genes overexpressed in ALDHhig subpopulation cells. Results The ALDHhig cells in tongue squamous cell carcinoma Tca8113 cell line was rarely 1.3%. Compared with ALDHlow cells and unsorted cells, ALDHhig cells demonstrated increased proliferation capacity. After culture in vitro, the percentage of ALDHhig cells decreased gradually to the level of that in unsorted tumor cells. The ALDHhig subpopulation cells could survive in serum free medium and generate tumorspheres. SSH analysis revealed these tumor cells also expressed stem cell related genes. Conclusion There is a rare subpopulation cells expressing ALDH highly, which displays characteristics similar to stem cells. ALDH may be one of markers for cancer stem cells of tongue squamous cell carcinoma Tca8113 cell line.

Key words: tongue squamous cell carcinoma, cancer stem cell, aldehyde dehydrogenase, suppression subtractive hybridization