ABSTRACT
Aim To investigate whether 8-bromo-7-methoxychrysin ( BrMC ) can reverse the epithelial-mesenchymal transition ( EMT) in sphere-forming cells (SFCs) derived from cervical cancer SiHa cell line. Methods Human cervical cancer SiHa cell line was cultured in vitro and then SFCs were obtained from Si-Ha cell line using suspension culture with the stem-condition culture system. After treatment with BrMC for 72 h, the morphology of SFCs of SiHa cell line was observed via monolayer adherence culture. The expres-sion levels of E-cadherin, N-cadherin and Twist1 pro-teins were analyzed using western blot assay. Results SFCs of SiHa cell line presented the mesenchyme-like( spindle-shaped) cell shape and exhibited reduced E-cadherin and elevated N-cadherin protein expres-sion, compared with the parental cells. After treatment with BrMC(1. 0 μmol·L-1 ) for 72 h, SFCs of SiHa cell line changed from spindle-shaped cells in to poly-gon shaped cells under monolayer adherence culture. After treatment with BrMC for 24 h, the expression lev-els of E-cadherin protein were up-regulated and the ex-pression levels of N-cadherin and Twist1 proteins were decreased in SFCs derived from SiHa cell line. Con-clusion BrMC effectively reverses EMT of SFCs de-rived from cervical cancer SiHa cell line, and its mechanism is involved in down-regulating the expres-sion of Twist protein.
ABSTRACT
Objective: The present study aimed to isolate and characterize a cancer stem cell-like sphere-forming cell subpopula-tion. Methods: By using a spheroid culture stem cell-conditioned medium, we isolated a subgroup of cancer stem-like cells from naso-pharyngeal cancer cell lines. Chemotherapy resistance was analyzed by using methyl thiazolyl tetrazolium, and clone-forming capabili-ty was determined by using softer agar clone formation assay. Finally, we verified the expression of the stemness-specific gene andβ-catenin by using immunocytochemistry staining and RT-PCR. Results: The lower-differentiated nasopharyngeal cancer lines con-tained more sphere-forming cells, whereas sphere-forming cells were not observed in the high differentiated nasopharyngeal cancer line CNE-1. Compared with CNE-2, CNE-2S (sphere-forming cells derived from CNE-2) exhibited higher chemotherapy resistance and clone-forming ability. Interestingly, the stemness genes BMI-1, ABCG2, and ALDH1 exhibited higher expression in CNE-2S than in CNE-2. β-catenin, a vital transcription factor of the WNT pathway related to stem cells, exhibited higher expression in CNE-2s cellular nucleus and plasma than in CNE-2. Conclusion: We isolated a subgroup of stem-like nasopharyngeal cancer sphere-forming cells. This discovery paves the way for the development of therapeutic strategies aimed at eradicating tumorigenic subpopulations in nasopharyn-geal cancer.