平阳霉素的体外抗癌谱

Anticancer Spectrum of Pingyangmycin in Vitro

采用集落形成试验法,对平阳霉素(pingyangmycin,PYM)的体外抗癌谱进行研究,结果10种人癌细胞系对PYM的敏感性存在差异,ID_(50)为0.03～0.82μg/ml。食管癌Eca109和CaEs17细胞、鼻咽癌CNE细胞及肝癌BEL-7402细胞对PYM敏感,ID_(50)<0.2μg/ml,与PYM的临床疗效一致;2种起源于宫颈癌的细胞系对PYM明显抗拒,ID_(50)>0.7μg/ml,与临床疗效不一致;2种胃腺癌细胞系(MGc80-3和BGC-823)对PYM的敏感性较低,ID_(50)为0.21和0.47μg/ml;肺鳞癌LTEP-78为PYM敏感细胞,ID_(50)仅为肺腺癌SPC-A-1细胞的1/7,但其临床意义尚不清楚。

Pingyangmycin (PYM), produced by Streptomyces pingyangensis n. sp., was found to be identical to bleomycin A5. In the present study, a comparative observation was carried out ia 10 human cancer cell lines. As determined by a colony-forming assay, the dose-response curves obtained from cells exposed to PYM for 1 h were of one type only: biphasic exponential. The sensitivities of these cells derived from different types of tumors, however, varied with a broad range of ID50 values (0.03-0.82μg/ml).A hepatoma cell line (BEL-7402) and three lines derived from squamous carcinomas of the esophagus (Eca109 and CaEs17) or the nasopharynx (CNE) were relatively sensitive (ID50<0.20μg/ml) to PYM which is known to have clinical activity against these diseases. Two gastric adenocarcinoma cell lines (MGc80-3 and BGC-823) and a pulmonary adenocarcinoma cell line (SPC-A-1) appeared to be less sensitive to the drug, with ID50 values of 0.21-0.47μg/ml. PYM was 7-fold more effective against LTEP-78 cells derived from pulmonary squamous carcinoma as opposed to SPC-A-1 cells, resulting in a low ID50 value of 0.04μg/ml. However, PYM as a single agent has not yet received full evaluation in relation to this type of lung cancer. In contrast with other cell lines of squamous cancer origin, HeLa and CC-801 cells derived from uterine cervix cacinomas which have been evaluated as highly responsive to PYM had the highest ID50 values (>0.70μg/ml).