The Experimental Study Of Ridioimmunoimaging And Therapy Of Breast Cancer With ～(131)I-Herceptin

Partâ… : Ridioimmunotherapy of breast cancer cell lines with ¹³¹I-HerceptinObjective : (1) To establish ¹³¹I-Herceptin with high labeling rate and purity .(2)To explore the biologic response of breast cancer cell lines expressing high level of Her-2 gene to ¹³¹I-Herceptin.Method: (1)Herception was labeled with ¹³¹I by the means of Iodogen. ¹³¹I-Herceptin was separated from excess ¹³¹I and Herception on a Sephadex G50 minicolumn and the quality control was carried out by paper Chromatography assay .(2)The inhibition effect of ¹³¹I-Herceptin on SK-BR-3﹑MDA-MB-231 and MCF-7 cell lines expressing different level of Her-2 gene was evaluated with MTT assay (.3) The DNA ploid and cell apoptosis rate of the intervention group and control group was evaluated by a flow cytometer .Results: (1)The labeling rate of ¹³¹I to Herceptin is 83.38% ,and the radiochemistry purity is 94.53%(.2)By MTT assay , the inhibition effect of ¹³¹I-Herceptin on SK-BR-3 cells was significantly higher than on MDA-MB-231﹑MCF-7 cells(P<0.05),also significantly higher than ¹³¹I group﹑Herceptingroup and ¹³¹I+Herceptin group (P<0.05).(3)By flow cytometer assay , the apoptosis rate of ¹³¹I-Herceptin group(37.71%) is significantly higher than the ¹³¹I group(0.93%)﹑Herceptin group(3.37%) and ¹³¹I+Herceptin group(14.61%)(P<0.01). We also can see significant cell cycle blockage in all intervention groups , especially in ¹³¹I-Herceptin group(73.19%)Conclusion: (1)The method of Iodogen for the labeling of Herceptin with ¹³¹I is easy and available .we can gain high labeling rate and little influence to the immunocompetence of the ntibody.(2) Breast cancer cell line SK-BR-3 express high level of Her-2 gene(99.30%).(3) ¹³¹I-Herceptin has significant inhibitive and killing effect on human breast cancer cell line SK-BR-3.Partâ…¡: Ridioimmunoimaging of breast cancer animal model with ¹³¹I-HerceptinObjective: (1)To establish Her-2 positive SK-BR-3 human breast cance xenografts in athymic mice (2) To image this xenografts with ¹³¹I-Herceptin.(3)To explore the biologic distribution of ¹³¹I-Herceptin in human breast cance xenografts ,to explore the ratios between tumor tissues and N-tumor tissues , to explore the uptakes percentage per gram of the injection dose (%ID/g).Method: (1)Implant SK-BR-3 cells subcutaneously in the shoulder of femal athymic mice to establish animal model .(2)Continuous imaging of the thymic mices bearing subcutaneous SK-BR-3 cell line was carried out at 2h,4h,8h,12h,24h,48h,96h postinjection of ¹³¹I-Herceptin or ¹³¹I-mIgG (.3)To measure the radiocounting per minute(cpm)of every organ on aγarithmometer at 4h,12h,24h,48h postinjection of ¹³¹I-Herceptin or ¹³¹I-mIgG , then to gain the T/NT ratios and the uptakes percentage per gram of the injection dose(%ID/g).Results: (1)After subcutaneous planted ,there were 36 out of 40 mice can form xenografts ,with a tumor formming rate of 96%.(2)We can see the image of local tumor at 2 hour postinjection , and the distinctest image appeared at 24h postinjection, at 96h postinjection ,we still can get a distinct image ; But in the control groups which were injected ¹³¹I-mIgG, we can only see the image of local tumor at first 4h postinjection, as time ran off, this image became indefiniter, we almost can not see the outline of the tumor at 96h postinjection(.3)In experimental group, the ratio of T/NT all exceed 3 except the tumor/kedny ratio, most of the T/NT ratio get its peak at 24h postinjection, and the descent of T/NT ratio is not significant at 96h postinjection ; However, in the control group ,wo did not get a T/NT ratio bigger than 1 except tumor/muscle and tumor/bone ,and no one bigger than 2 . In experimental group ,the uptakes percentage per gram of the injection dose(%ID/g)at 24h is 14.8%ID/g ,compared with 2.05%ID/g in control group .Conclusion: (1)A high tumor formming rate(96%) can get by implanting SK-BR-3 cells subcutaneously to athymic mouse.(2)A distinct image of the thymic mice bearing subcutaneous SK-BR-3 cell line can get by injecting ¹³¹I-Herceptin.(3)We can get a ideal T/NT ratio postinjecting of ¹³¹I-Herceptin ,and this ratio get its peak an 24h postinjecting.