Establishment and characterization of chronic-hypoxia-resistant gastric cancer cell line MNK45/HYP.

The chronic-hypoxia-resistant gastric cancer cell line was established, and its biological characteristics were explored and compared with the parental cell line. Gastric cancer cell lines were cultured under the degressive oxygen concentration. Cell doubling time was calculated by cell counting method. Chemo-resistance ability of cells was tested by MTT assay. Irradiation tolerance of cells was evaluated by colony forming method. Cell cycle distribution was tested with flow cytometry. Invasive ability was tested by Transwell method. The expression levels of GLUT-1 and HIF-1α were detected by using Western blot. MNK45/HYP cells successfully survived under the 1% concentration of oxygen and its cell doubling time was 35.01±1.02 h, while that of MNK45 was 27.35±0.83 h (P<0.01). The percentage of MNK45/HYP cells in G(0)/G(1) stage was (58.3±6.1)%, and that of MNK45 cells was (42.2±6.0)% (P<0.05). Comparing with the parental cells MNK45, drug resistance indexes of 5-Fu, PTX, OXA, Sn38, GEM and VP16 in MNK45/HYP cells were respectively 5.3, 1.3, 3.6, 2.2, 4.8 and 4.4. Colony forming ability of MNK45/HYP cells after irradiation was also significantly higher than MNK45 cells. The invasive number of MNK45/HYP cells was 107.7±17.5, while that of MNK45 cells was 59.0±9.9. The expression levels of GLUT-1 and HIF-1α in MNK45/HYP cells were significantly higher than those in MNK45 cells. MNK45/HYP cells hold biological characteristics of hypoxia tumor with good tolerance to chronic hypoxia, and can be used for the research of solid tumor under chronic hypoxia condition.