The Inhibition Effects Of Several Secondary Phosphorylated Forms Of Inositol Hexaphoshpate(ip6) On Human Colon Cancer Cell HT-29

Objective: To compare the effects of secondary phosphorylated forms of inositol hexaphosphate(IP6) on human colon cancer cell line HT-29 in vitro and to discuss the associated mechanisms.Methods:1. MTT was used to assess inhibition rates at different concentrations of IP3, IP1,IP6 on HT-29 cells in 48 h, and the IC50 was calculated according to inhibition rates(IC50).2. Apoptosis ratio and cell cycle in HT-29 were determined by flow cytometry with different concentration of IP3 and IP6 on HT-29 cells.3. To investigate the expression of PCNA, Bcl-2 and Bax protein with different concentration of IP3 and IP6 on HT-29 cells by immunocytochemistry.4. The expression of P53, Bcl-2, and Bax mRNA were determined by Real-time PCR with different concentration of IP3 and IP6 on HT-29 cells.5.The P53 protein expression was detected by Western blot method with IP3 and IP6 on HT-29 cells.Results:1. IP3,IP1, IP6 could inhibit the proliferation of HT-29 cells. Meanwhile, IP3,IP1 had more significant effects than IP6,espcially,IP3 had a most significant effect(P<0.05).IC50 of IP3, IP1,IP6 separately at 48 h were 2.3mmol/L, 3.3mmol/L, and 3.5mmol/L.2. Compared with the control group, more cells in the intervention group were trapped at Gl phase in IP3-treated and IP6-treated groups(P<0.05) and IP3 showed more significant influence. With the increasing of dose of IP3 and IP6, apoptosis rates of HT-29 cells in intervention groups were gradually increased. Especially, IP3 had a more significant effect, compared with the IP6-treated group.3. The expression of PCNA, Bcl-2 protein of HT-29 cells were decreased but Bax protein was increased after the intervention of IP3 and IP6,compared with the control group, the differences were significant(P<0.05). IP3 had a more significant effect4. The expression of P53, Bcl-2 mRNA decreased, while, the expression of Bax mRNA was increased in IP6-treated and IP3-treated groups,compare with the control group. Especially, at the same dose, IP3 exhibited more significant influence on HT-29 cell.5. IP3 and IP6 both could reduce the expression of P53 protein(P<0.05)compared withcontrol. IP3 had a more obvious effect.Conclusion: The Secondary phosphorylated forms of IP6 all could inhibit the growth of HT-29 cells,the effects of IP3, IP1 are better than IP6, and IP3 had a most significant effect.It could suppress the expression of PCNA,P53,Bcl-2 protein.While the promotion of expression of Bax protein was concerned with inhibiting cancer cell proliferation and promoting apoptosis.