99mTc-CXCR4抑制性多肽在荷乳腺癌小鼠显像中的应用

摘要

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Ⅱ N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 9999mTc-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 9999mTc-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-la 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.