The Effect Of Tumor Metastasis Associated Gene 1 (MTA1) On The Process Of EMT In Esophageal Squamous Cell Carcinoma Isolation And Biological Characteristics Of Sphere Cells From Cervical Cancer Cell Line

[Objective] To explore the effect and mechanism of metastasis associated gene 1 (MTA1) on epithelial-mesenchymal transition (EMT) of esophageal squamous cell carcinoma (ESCC).[Methods] Lentivirus vector was used to establish the MTA1 knocking down cell line and MTA1-overexpressing cell line. Western blot assay was used to detect the levels of MTA1 and other proteins associated with EMT process. Furthermore, the expression and localization of E-cadherin and Vimentin were observed by immunofluorescence assay under confocal microscope. Then, the wound healing assay was performed to confirm the changes of migration ability of the established cell lines. The effect of SOX2-overexpression in MTA1 knocking-down cells was observed. Finally, we used the immunohistochemical staining to detect the expression of MTA1 and SOX2 in esophageal cancer tissues and analyzed the correlation between MTA1 and SOX2.[Results] When KYSE-450 cells were overexpressed with MTA1, E-cadherin was down-regulated while Vimentin was up-regulated, and the migration ability was enhanced (p<0.05). However, when MTA1 was knocked down in KYSE-410 cells, E-cadherin was up-regulated while Vimentin was down-regulated, and the migration ability was attenuated (p<0.05). Overexpression of SOX2 could down-regulate the expression of E-cadherin and up-regulate the expression of Vimentin and restore the ability of migration which has been affected by MTA1 knocking out. As shown in the results of immunohistochemical staining, MTA1 and SOX2 expression in tumor tissues were significantly stronger than in normal tissues (p<0.05). Expression of MTA1 and SOX2 was strongly associated with the lymph node metastasis (p<0.05). The survival of the patients with positive MTA1 and SOX2 expression is shorter than that of those with negative MTA1 and SOX2 expression (p<0.05). Significant correlation was observed between MTA1 and SOX2 (p<0.05).[Conclusion] Down-regulation of MTA1 inhibits the process of epithelial-mesenchymal transition and attenuates the migration ability of ESCC, which might be related to the consequent down-regulation of SOX2. Overexpression of MTA1 and SOX2 positively correlates with the poor prognosis of ESCC patients.[Object] The present work aimed to identify and characterize a cancer stem cell population from the CaSki cell line.[Methods] First, we used the stem cell culture medium to selectively expand cancer stem-like cell spheres and identified the putative sternness markers, OCT4 and SOX2. Then, we performed the Target Region Amplified Polymorphism-Polymerase Chain Reaction (TRAP-PCR) to test the telomerase activity. Using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazol ium (MTS) assay to make sure the drug resistance of the cancer stem-like cell spheres. Finally, we used the tumor invasive assay to investigate the invasive ability of cancer stem-like spheres. These characteristics all suggest that the tumor sphere-forming cells mirrored the acknowledged cancer stem cells phenotypes.[Results] The stem cell markers are all highly expressed in CaSki sphere-forming cells and the CaSki sphere-forming cells had higher telomerase activity than CaSki cells cultured in non-stem cell medium. We also found that the CaSki sphere-forming cells were more resistant to chemotherapeutic drugs than adherent single-layer CaSki cells. It was shown that the CaSki sphere-forming cells were more invasive than adherent single-layer CaSki cells.[Conclusion] The suspended sphere culture of CaSki may be an easy and feasible approach for enriching cancer stem-like cells in cervical cancer research.