cRGD肽二聚体对B16黑色素瘤细胞的体外抑制作用及在荷瘤鼠体内分布及显像研究

摘要

目的 探讨cRGD肽二聚体对B16黑色素瘤细胞的体外抑制作用及其在荷B16黑色素瘤细胞小鼠动物模型体内的分布及显像研究.方法 用MTT法检测不同浓度及作用时间cRGD肽二聚体对B16黑色素瘤细胞体外增殖能力的影响.采用直接标记法标记99 Tcm-c(RGD)2.建立荷B16黑色素瘤株动物模型,待肿瘤体积为1.0 ～ 1.5cm3左右时,分别于30min、1h、2h、3h、4h、5h及6h时,进行荷瘤鼠体内生物分布及动态显像研究.结果 cRGD肽二聚体浓度为500mg/L、作用48h时,对B16黑色素瘤细胞的增殖具有明显的抑制作用.室温下、ρ(SnCl2·2H20)=1 g/L、反应时间为30 min时,99Tcm-c(RGD)2的标记率可达(87.42±3.21)％,标记产物经Sephadex G10分离纯化后放射化学纯度大于95％;静脉注射后30min行小鼠全身SPECT显像,肿瘤部位可见明显显像剂聚集,但肿瘤与周围组织的对比度较低;延迟至6小时肿瘤仍清晰可见,且随时间延迟肿瘤与周围组织的对比度增高,此时肿瘤/血液为2.15±0.24,肿瘤/肌肉为5.07 ±0.03.结论 该结构cRGD肽二聚体对B16黑色素瘤细胞株具有一定的体外抑制作用,且动物体内肿瘤组织摄取率高,显像清晰,证明其可进一步应用于聚合物多肽靶向药物的研发.%Objective To investigate the inhibitory effects of c (RGD)2 peptide on proliferation of B16 melanoma cells in vitro and the imaging and biodistribution study with 99TCm-C(RGD) 2 tracer in a xenograft B16 melanoma beating mice model.Methods The cell proliferation was assessed by MTT assay.We labeled 99TCm-c(RGD)2 peptide with the direct labeling method.The strain B16 melanoma cells were cultured to build the animal model.To generated solid tumors,5 × 106 melanoma cells were injected s.c.into the armpit of KM mice.When the tumors reached 1.0-1.5cm3,the imaging and biodistribution experiment were performed at 30min,1,2,3,4,5,and 6 hour respectively after intravenous injection in tumor-bearing mice.Results With 500mg/L c(RGD)2 after 48h,the proliferation of B16 melanoma cells was significantly decreased.With 1 g/L SnC12 · 2H2O and the 30 min of reaction time,Labeling efficiency of 99Tcm-c(RGD) 2 reached (87.42 ± 3.21) ％.After Sephadex G10 purification,the radiochemical purity was no less than 95 ％.SPECT imaging clearly revealed at 30min post-injection,even though the contrast was poor.At 6 hours time point,tumor was still clearly visible,and the contrast was getting sharper with time lasted,with tumor/blood was 2.15 ± 0.24,tumor/muscle was 5.07 ± 0.03.Conclusion The results in vitro showed the inhibition effect of c(RGD)2 on B16 melanoma. And in vivo 99TCm-c(RGD)2 could be well located in tumor. The data demonstrated that c(RGD) 2 was suitable for the further development of polymer-conjugated RGD peptide targeted-drugs.