Study On ¹⁸F-FETNIM Micro PET/CT Evaluation Of Irisquinone Radiosensitizing Effect On MDA-MB231 Breast Cancer Radiotherapy In Nude Mouse

SubjectTo understand the characteristics of ¹⁸F-FluoroerythronitroimidazoleMicro Positron Emission Computed Tomography(¹⁸F-FETNIM Micro PET/CT)imaging in the subcutaneous MDA-MB231 breast cancer model of nude mice before and after radiotherapy.To evaluate the radiosensitizing effect of irisquinone（IR）in MDA-MB231breast cancer model and to investigate the value of ¹⁸F-FETNIM micro PET/CT in evaluating the radiosensitivity enhancement of malignant tumors.MethodsThirty-two MDA-MB231 breast cancer modles of nude mice were divided into 4 groups by random number table method（n=8 for each group）:group A with radiotherapy alone,group B with radiotherapy and IR,group C with IR alone,and group D without radiotherapy or IR（the control group）.¹⁸F-FETNIM microPET/CT images were obtained to monitor the SUV_maxax of ¹⁸F-FETNIM uptake before radiotherapy and 24h after radiotherapy.The tumor tissues were stained by HE,and the expression of HIF-1αwas detected by immunohistochemical（IHC）method.Data were analyzed by paired t test,two sample t test,one-way analysis of variance,LSD-t test and Pearson correlation analysis.ResultsBefore radiotherapy,the SUV_maxax in A、B、C and D groups were 1.429±0.090,1.430±0.076,1.445±0.071,1.432±0.074 respectively,there was no significant difference in SUV_maxax among the 4 groups（F=0.072,P>0.05）.At 24 h after radiotherapy,the values were 1.075±0.098,0.890±0.076,1.617±0.090,1.644±0.063 respectively.The SUV_maxax of group A and B decreased compared with the values before radiotherapy and the differences were statistically significant（t values:12.888,33.217,both P<0.05）,and the SUV_maxax of group B decreased more significantly（t=4.197,P<0.05）;However,the SUV_maxax of group C and D increased than that before radiotherapy,and the differences were statistically significant（t values:-11.009,-16.061,both P<0.05）.Pathological results showed that the number of tumor cells in group A and B were significantly reduced,while group B was reduced more significantly.IHC results showed that the positive expression of HIF-1αwas significantly lower in group B than that in other groups（P<0.05）.The expression of HIF-1αwas positively correlated with SUV_max（r=0.89,P<0.05）ConclusionIR has a certain application radiosensitizing effect in MDA-MB231 breast cancer modles,and ¹⁸F-FETNIM micro PET/CT can evaluate the radiosensitizing effect exactly and noninvasively by assessing the hypoxic state in tumor.