肿瘤坏死因子基因克隆表达及其抗瘤活性的研究

Studies on the gene clone,expression and anticancer potential of tumor necrosis factor

本文根据已发表的肿瘤坏死因子(TNF)氨基酸序列和核苷酸序列,用大肠杆菌偏性密码人工合成全基因,并在大肠杆菌中表达,表达量占总菌体蛋白的22～33%,均为可溶性TNF·菌体裂解液经抗TNF 单抗亲和柱纯化后得到SDS—PAGE 上分子量为17KD 的单带蛋白,比活性1～4×10~7u/mg。体外细胞毒试验表明:部分人肿瘤细胞系例如HL-60、Molt-4、OVCAR-3等对TNF 很敏感;部分肿瘤细胞例如KG_1、H7402等对TNF 呈中等敏感;也有部分肿瘤细胞对TNF 不敏感。从白血病患者周血来的原代白血病细胞对TNF 也呈现不同敏感性。TNF 与各种化疗药物,如阿霉素(AD)、更生霉素(KSM)等,或某些细胞因子,如γ-干扰素(IFN-γ)等联合应用时,对肿瘤细胞的杀伤有协同作用。裸鼠移植瘤模型上也观察到不论瘤内局部注射还是腹腔注射,均能明显抑制肿瘤生长,如果TNF 与化疗药物合用则抑瘤效果更好。

Based on published amino acid and nucleotide sequence,tumor necrosis factor gene was syn-thesized and expressed in Ecoli MM294.Purified TNF by immuno—affinity column showed oneband MW.17000 on SDS—PAGE.In vitro the antitumor effects of TNF are very specific forhuman malignant cells.About one third of human cancer cell lines are exquisitely sensitive to thecytolytic effects of TNF.Another third shows cytostasis without lysis,and another third are rel- atively resistant to TNF.In the presence of low concentration of chemotherapeutic agents,TNFincreased the lysis of leukemia patients malignantt cells.The therapeutic effect of TNF andchemotherapeutic drugs was examined using human malignant cells transplanted in nude mice.