卵巢癌特异性结合肽OSTP的鉴定

The Specific Binding of 5-FAM-OSTP With Ovarian Cancer Cell A2780

目的验证卵巢癌特异性结合肽(OSTP)对卵巢癌A2780细胞的特异性结合作用。方法合成OSTP并标记荧光素5-FAM。将培养的卵巢癌A2780细胞及对照组胃癌SGC7901细胞、骨肉瘤MG63细胞分别加5-FAM-OSTP孵育,荧光显微镜下观察拍照。构建卵巢癌A2780细胞荷瘤小鼠模型,尾静脉注入5-FAM-OSTP,循环1 h后进行左心室灌注,取肿瘤组织及各脏器组织,行冰冻切片,荧光显微镜下观察拍照。结果成功合成和标记5-FAM-OSTP。荧光显微镜观察显示:5-FAM-OSTP孵育后的卵巢癌A2780细胞产生明亮的黄绿色荧光,而对照组SGC7901、MG63细胞不产生荧光。裸鼠体内实验结果显示:肿瘤组织可见强荧光信号,平均荧光强度为17.656±1.980;肝组织平均荧光强度4.277±0.291;肾组织平均荧光强度4.422±0.767;其他脏器均无可见荧光信号。肿瘤组织与肝、肾组织的荧光强度间差异有显著性(P<0.05)。结论通过体内外实验证实了5-FAM-OSTP对卵巢癌A2780细胞具有特异结合作用,有望成为卵巢癌靶向化疗药物的导向肽。

Objective To verify that ovarian cancer specific targeting peptide（OSTP） is binding to ovarian cancer A2780 cell specifically which we have screened via phage display in vivo. Methods Synthesized OSTP and marked fluorescein 5-FAM. Added 5-FAM-OSTP to incubated ovarian cancer A2780 cells and gastric cancer SGC7901 cells of control group,bone sarcoma MG63 cell respectively, which were examined by fluorescence microscope. Constructed ovarian cancer A2780 cells mouse models, then 5-FAM conjugated OSTP was injected into the tail vein and allowed to circulate for I h. The mice were perfused with PBS through the left ventricle to remove unbound peptides. Tumors and control organs were excised,and frozen sections were prepared and examined by fluorescence microscopy. Results 5-FAM-OSTP was synthesized and marked successfully. The result of fluorescence showed, after the incubation of 5-FAM-OSTP ovarian cancer A2780 cells appeared bright yellow green fluorescence, while SGC7901 cell and MG63 cells did not appear fluorescence. The results of mouse in vivo targeting studies revealed, the tumor tissue had strong fluorescence signal, the average fluorescence intensity was 17. 656 ± 1. 980 ;Hepatic average fluorescence intensity was 4. 277 ±0. 291 ;Renal average fluorescence intensity was 4. 422 ± 0.767 ; Other organs were not found to have fluorescence signal. The fluorescence intensity of tumor tissue is different from liver,kidney,and the differences have statistical significance （P 〈 0.05）. Conclusions 5-FAM- OSTP was tested in vivo and vitro for its binding specificity and affinity to ovarian cancer A2780 cells, OSTP maybe is the homing peptide of ovarian cancer targeted chemotherapy drugs.