Preliminary Study On Inhibition Effects Of Static Magnetic Fields (SMF) With Antineoplastic Drug Of Hydroxycamptothecin On Hepa1-6(Mouse Hepatoma Cell)

The synergistic anticancer effects of magnetic fields withhydroxycamptothecin on Hepa1-6 (mouse hepatoma cell) were studied and mechanismswere also discussed preliminarily.Methods: 1. Growth of Hepa1-6 cells were detected by MTT test after inoculationwith different initial cell density and at different time; the growth curve was draw to getproper initial cell density of anticancer drug treatment. 2. Hepa1-6 cells were treatedwith hydroxycamptothecin of different concentration for 24h and detected by MTT testin order to get proper hydroxycamptothecin concentration in treating Hepa1-6 cellscombined with static magnetic fields (SMF). 3. The influence of SMF or/andhydroxycamptothecin on Hepa1-6 cells were detected by MTT test. 4. The morphologicmodification of Hepa1-6 cells exposed under SMF with hydroxycamptothecin wereobserved by atomic force microscopy (AFM); DNA damage and cell cycle distributionof Hepa1-6 cells exposed under hydroxycamptothecin or/and SMF were measured bySingle cell gel electrophoresis (SCGE) and flow cytometer (FCM) .Results: 1. Hepa1-6 cells with initial density of 1×10~5cells/mL were inlogarithmic growth phase within 60h by MTT test; so 1×10~5cells/mL could be used asinitial cell density in the study on synergistic effects of SMF and hydroxycamptothecin.2. When Hepa1-6 cells were treated with hydroxycamptothecin of concentration of0.01, 0.5, 0.1, 0.2, 0.4, 0.8, 1.2μg/mL, the results showed the growth of Hepa1-6were inhibited by hydroxycamptothecin of 0.2μg/mL and above, and the cellactivities were significantly reduced (P＜0.01) .3. The growth of Hepa1-6 cells with initial density of 1×10~5cells/mL wasinhibited after exposure of SMF for 36h; When Hepa1-6 cells were treated with SMFand hydroxycamptothecin (0.2μg/mL) for 24h, the cell activities were significantlyreduced compared with single drug treatment (P＜0.05) .4. When Hepa1-6 cells were treated with SMF and hydroxycamptothecin (0.2μg/mL) for 24h, there were some changes in the morphology of Hepa1-6 cells, such assome protuberances and holes-like structures appeared on the cell surface; but DNAdamage were not detected. The cell cycle distributions were changed and the ratio of cells at G2/M phase significantly increased.Conclusion: SMF can enhance the anti-cancer effects of hydroxycamptothecinunder certain conditions, mostly in the decrease of cell activities, changes of cellmorphology and G2/M phase arrest, but DNA damage was not detected, suggesting thatunder certain exposing concentration and time the synergistic anticancer effects of staticmagnetic fields(SMF) with hydroxycamptothecin on Hepa1-6 cells were probablyattributed to the arrest of cell cycle progression.