A study on anti-angiogenesis peptides labeled with technetium-99m

Objectives This work was aimed at finding a 99mTc-labeled tracer for tumor angiogenesis studies.

Methods Three anti-angiogenesis peptides, with appropriate structural modified, were labeled with 99mTc and screening in vivo on the tumor-bearing mice. The anti-angiogenesis peptide confirmed with highest accumulation of radioactivity in tumor was chosen for the tissue distribution and tumor competition on the tumor bearing mice, and compared with 99Tcm -RGD and 18F -FDG through imaging on xenoplanted VX2 tumors and inflammation in rabbit model.

Results 99Tcm-HYNIC- A(D)A(D)APRPG the highest activity distribution in tumor (%ID/g =13.5973±1.3642) with very low background activities in non-tumor tissues, and was quite stable with high radio labeling ratio (Radiochemical purity>98%). 99Tcm-HYNIC- A(D)A(D)APRPG was low uptake at inflammation tissue,and high uptake at tumor focus. Pathological examination validated that the tissues with accumulation of 99Tcm-HYNIC- A(D)A(D)APRPG were enriched with tumor cells. The ratios of tumor / inflammation was highest at 2h post-injection(3.25±0.171). The ratios of tumor / inflammation of 99Tcm-HYNIC- A(D)A(D)APRPG were higher than that of 99Tcm -RGD (2.37±0.076) and 18F -FDG (1.171±0. 103) (F2h=15.63,P1h=0.000879,P<0.01).

Conclusions 99Tcm-HYNIC- A(D)A(D)APRPG is suitable as a tracer of tumor angiogenesis,which has the specificity to differentiate the malignant tumor and inflammation.

Research Support The study was supported by research grants from National Natural Science Foundation of China (No. 30830038)Commission of Shanghai Municipality (No. 10JC1410000); Shanghai Leading Academic Discipline Project(No.S30203)