Research On The Effect Of Ketogenic Diet On Tumor Growth Of Astrocytoma Model In Nude Mice

Objective: To establish subcutaneous transplantation model of U87 glioma in Balb/c mice and observe the effect of ketogenic diet on tumor growth of subcutaneous transplantation models of U87 glioma in Balb/c mice.Methods: 20 female Balb/c mice were injected subcutaneously with U87 glioma cells. After that, mice were randomly divided into two groups, the ketogenic diet group and the standard diet group, each group had 10 mice. The change of tumor volume was measured. The growth lines of tumor were drawn. The serum glucose and ketone body were measured every 6 days. Using the infrared imaging to observe the growth of glioma and monitor the change of tumor’s temperature. At the sixth day after inoculation, the temperature of glioma were measured with infrared thermal imager every 3 days. At the 12 th day after inoculation, the tumor volume of Balb/c mice reached above 100m3, one group was fed with a ketogenic diet, and the other group was given a standard diet. The group of ketogenic diet required restricted calorie ketogenic diet. The nude mice were killed on 36 days after inoculation. Using tumor tissues to make HE staining, GFAP and CD31 immunohistochemically staining.Results:(1)The growth of tumor volume of the KD group was more delayed than in the SD group. At the 36 th day, the tumor volume of SD and KD groups reached at 1397.6±205.8mm3 and 1046.5±214.9 mm3, the volume of tumor between two groups had shown significance(P<0.05).(2)The ketone body in the KD group was elevated while the blood glucose was decreased. At the 36 th day after inoculation, the ketone body of KD and SD groups reached at 1.77±0.37mmol/l,SD and 0.36±0.18mmol/l, the ketone body between two groups had shown significance(P<0.05). At the same time, the serum glucose of KD and SD groups reached at 3.07±0.52mmol/l,SD and 4.92±0.30mmol/l, the serum glucose between two groups had shown significance(P<0.05).(3)The average temperature of tumor between KD and SD group failed to show significance(P>0.05).At the early growth of tumor in each group, the temperature of tumor increased gradually with the development of time. The temperature of tumor had reached the highest at 15 th day after the beginning of the experiment. In the late of tumor’s growth, the of temperature of tumor de-creased with the development of time. Compared the temperature of tumor in each group at the 36 th day after inoculation with the 6th day after inoculation, which had shown significance(P<0.05).(4)Positive immunohistochemically expression of GFAP in glioma was to prove the tumor tissue being a part of glial tumors.(5)The glioma capillary number of KD group reached 30.56±3.93, while the SD group was 37.33±9.05, these two groups failed to show significance(P<0.05).Conclusion:(1) Ketogenic diet can delay the increasing volume of tumor of subcutaneous transplantation models of U87 glioma in nude mice.(2) The ketogenic diet can reduce the number of new blood vessels in tumor tissues.