^(99m)Tc-CXCR4抑制性多肽在荷乳腺癌小鼠显像中的应用

The application of ^(99m)Tc-CXCR4 inhibitory peptides in imaging of breast cancer-bearing mouse

目的:探讨99mTc标记拮抗趋化因子受体(CXCR4)来源于病毒巨噬细胞炎性蛋白ⅡN端肽(NT21MP)作为乳腺癌SPECT显像剂的应用价值。方法:预锡化法标记NT21MP,纸层析法测99mTc-NT21MP放化纯及其在血浆中的稳定性;制备荷乳腺癌小鼠模型,静脉注射99mTc-NT21MP行SPECT显像,并计算靶/非靶(T/NT)比值;免疫组织化学法检测肿瘤组织CXCR4的表达和肺组织SDF-1α的表达。结果:预锡化法标记99mTc-NT21MP放化纯达95%;血浆中2 h内稳定,2 h放化纯>90%;99mTc-NT21MP注射后能靶向肿瘤组织,2 h的T/NT比值达4.6;肿瘤组织高表达CXCR4,而肺组织高表达SDF-1α。结论:99mTc-NT21MP易于制备,具有较高的靶向性,在CXCR4阳性肿瘤的早期诊断中具有较高的应用价值。

Objective： To explore the application value of the 99mTc-CXC chemokine receptor 4（CXCR4） inhibitor derived from virus macrophage inflammatory protein（NT21MP） as SPECT imaging agent in mouse breast cancer.Methods： NT21MP was directly radiolabeled using pretinning method.The radiochemical purity and stability of 99mTc-NT21MP in plasma was measured by chromatographic system.The mouse model of breast cancer was established.SPECT imaging of model mice were detected by intravenous injection 99mTc-NT21MP.T / NT value was calculated,and the expressions of CXCR4 and SDF-1α in tumor and lung tissue were detected by immunohistochemistry method.Results： The radiochemical purity of 99mTc-NT21MP was 95%.It was stable in blood plasma within 2 hours,its radiochemical purity was more than 90%.99mTc-NT21MP could target to tumor tissues after injecting.T / NT reached 4.6 in 2 hours,the expression of CXCR4 and SDF-1α were high in tumour and lung tissue,respectively.Conclusions：99mTc-NT21MP is easily prepared,and high targeting,which has high application value in early diagnosis of CXCR4 positive tumor.