The Inhibition Effect And Mechanism Of Inositol Hexaphosphoric Acid On SKOV3 Subcutaneously Implanted Tumor Model In Nude Mouse

Objective: Research of inhibition and mechanism of inositol hexaphosphoric acid?IP6?to subcutaneous transplantation tumor growth and proliferation in nude mice.Methods:1 Cell culture: Human epithelial ovarian cancer cell line SKOV3 were cultivated in RPMI-1640,which contained 10% new-born calf serum,at 37 ? and 5% CO₂ saturated humidity incubator.2 The establishment of subcutaneously transplanted tumor model in nude mice and experimental groups:Inject the SKOV3 cells in logarithmic phase subcutaneously in the back near the right shoulder blade in nude mice.5 days after inoculation,choose 30 nude mice with about 3⁵-mm-diameter tumor,and randomly and averagely divide them into five groups: control group,low dose IP6 group,high dose IP6 group,cisplatin group and combination group with low-dose IP6 and cisplatin.3 Drug preparation:Dissolve The mixture of IP6 and inositol in 0.9% sodium chloride to get solution containing 3 mg IP6 per ml and solution containing 6 mg IP6 per ml Dissolve Cis-platinum in 0.9% sodium chloride to get solution containing 0.3 mg cis-platinum per ml.All should be used immediately.4 Administration method:control group,0.1ml/g 0.9% sodium chloride intragastric administration once a day for 28 days,the same volume of 0.9% sodium chloride intraperitoneal injection once a day for a week.low-dose IP6 group,intragastric administration once a day for four weeks.high-dose IP6 group,intragastric administration once a day for four weeks.Cis-platinum group,3mg/kg intraperitoneal injection once a day for a week.Combinition group,the same administration as low-dose IP6 group and cis-platinum group.5 General condition of the nude mice ? weight and volume of the transplanted tumor?tumor inhibiting rates:Observe the spirit,diet,activities,urination and defecation of nude mice every day.Measure the weight of nude mice and the longest diameter?a?and the shortest diameter?b?of the transplanted tumor every 7 days,and calculated the volume of the transplanted tumor by the formula: V?mm³?=ab²/2.Take off and weight the transplanted tumor 24 hours after the last injection.Calculate the tumor inhibiting rates?IR??%?=?the mean weight of control group-the mean weight of treatment group?/ the mean weight of control group×100%.6 Detect the expression of the CyclinD1 by immumohistochemical method.7 Detect the expression of miRNA let-7 by Real Time-PCR method.8 Statistical method:Process and analyze experimental data by SPSS20.0 statistical software.Describe the measurement data by x±s.Compare multisamplet mean by the single factor variance analysis or Kruskal-Wallis H test,P < 0.05 for differences with statistical significance.Compare the difference between two groups by SNK-q test.Results:1 The experiment processed smoothly.Some nude mice depressed,moved slowly and ate little.The general condition of treatment groups containing IP6 was better than the cis-platinum group.With the time passing by,the weight of nude mice and the volume of transplanted tumor increased.Weight of nude mice at the twenty-ninth day?x±s?: control group 22.27±2.34 g,low-dose IP6 group 22.42±1.73 g,high-dose IP6 group 22.36±1.67 g,cis-platinum group 20.15±0.66 g,combination group 22.00±1.47 g,and difference was statistically significant?P<0.05?.The volume of transplanted tumor at the twenty-ninth day ranged as following: combination group<cis-platinum group<high-dose IP6 group<low-dose IP6 group<control group,and difference was statistically significant?P<0.05?.Weight of transplanted tumors at the twenty-ninth day?x±s?: control group 3.38±0.017 g,low-dose IP6 group 3.11±0.018 g,high-dose IP6 group 2.83 ± 0.017 g,cis-platinum group 2.80±0.040 g,combination group 2.63±0.033 g,and difference was statistically significant?P<0.05?.IR arranged : combinition group>cis-platinum group> high-dose IP6 group> low-dose IP6 group.2 The expression of CyclinD1 in transplanted tumor: CyclinD1 was expressed in every group.The expression was arranged as combination group<cis-platinum group< high-dose IP6 group< low-dose IP6 group< control group,and difference was statistically significant?P<0.05?.3 The expression of miRNA let-7 in transplanted tumor: MiRNA let-7 was expressed in every group.The expression was arranged as combination group>cis-platinum group> high-dose IP6 group> low-dose IP6 group> control group,and difference was statistically significant?P<0.05?.Conclusions:1 Compared with the control group,treatment groups can restrain the growth of the transplanted tumor.Compared with cisplatin alone,combination of IP6 and cisplatin can more effectively inhibit the growth of transplanted tumor and reduce side effects causing by cisplatin.2 It is supposed that IP6 can play antitumor effect by inhibiting the expression of CyclinD1 and preventing the tumor cells to G1/S phase.3 It is supposed that IP6 can play antitumor effect by increasing the expression of miRNA let-7.