短肽修饰的甲氨蝶呤的制备及细胞毒性作用

Preparation of methotrexate modified by small peptide and study on its cytotoxic effect

目的:制备促黄体激素释放激素-甲氨蝶呤(LH-RH-MTX)并考察其对表达有促黄体激素释放激素(LH-RH)受体的肿瘤细胞的毒性作用。方法:以临床抗恶性肿瘤药物甲氨蝶呤(MTX)为模型药物,以促黄体激素释放激素[D-Lys6]LH-RH为导向物,通过共价键连接制备LH-RH-MTX。应用MTT法分别考察游离MTX和LH-RH-MTX对鼻咽癌HNE-1及前列腺癌PC-3细胞株的细胞毒性作用。结果:MTT法结果表明游离MTX和LH-RH-MTX对2种细胞株均有生长抑制作用,对前列腺癌PC-3细胞的抑制率大于鼻咽癌HNE-1细胞;给药12h后抑制率达到最大;当药物质量浓度为200.0μg.L-1,作用12h后:LH-RH-MTX对前列腺癌PC-3细胞的抑制率可高达97.73%,游离MTX为49.90%;LH-RH-MTX对鼻咽癌HNE-1细胞的抑制率为38.92%,游离MTX为7.41%;在同一种细胞株上,LH-RH-MTX的IC50值小于游离MTX。结论:经过短肽修饰的化合物LH-RH-MTX可与表达有LH-RH受体的肿瘤细胞特异性结合并发挥抑制作用,抗肿瘤活性高于游离MTX。提示用LH-RH作为TDDS的导向物,实现药物的靶向释放,提高药物生物利用度是可行的。

OBJECtIVE To prepare LH-RH - MTX and investigate its cytotoxic effect on cells with LH-RH receptors.METHODS MTX as the model drug and [D-Lys^6] LH-RH as the carrier were selected to prepare LH-RH - MTX. MTT assay was applied to examine the cytotoxic effects of LH-RH - MTX and free MTX on the nasopharyngeal carcinoma HNE-1 cell line and the prostatic carcinoma PC-3 cell line. RESULTS The results showed that free MTX and LH-RH - MTX could both inhibit the growth of the two cell lines. The inhibitory ratio on prostatic carcinoma PC-3 cells was higher than that on nasopha- ryngeal carcinoma HNE-1 cells. The inhibitory ratio was the highest after administration for 12 h. At the concentration of 200 μg·L^-1 after administration for 12 h,the ratio of LH-RH - MTX on prostatic carcinoma PC-3 cells was up to 97. 73% and that of free MTX was 49. 90%; on nasopharyngeal carcinoma HNE-1 cells, the inhibitory ratios were 38. 92% and 7. 41 %, respec tively. To the same cell line,the IC50 of LH-RH - MTX was less than that of free MTX. CONCLUSION The compound LH- RH - MTX modified by small peptide can incorporate specifically with the tumor cells with LH-RH receptors and its anti-tumor activity is higher than that of free MTX. The present study indicates that it is feasible to select LH-RH as the carrier of TDDS to deliver drugs targetedly and increase their bioavailability.