Puri R K, Hoon D S, Leland P, Snoy P, Rand R W, Pastan I, Kreitman R J
Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, Food and Drug Administration, NIH, Bethesda, Maryland 20892, USA.
Cancer Res. 1996 Dec 15;56(24):5631-7.
Effective treatment is lacking for malignant glioblastoma/astrocytoma. We have identified interleukin-4 receptors (IL-4R) on human malignant astrocytoma. We demonstrate that 16 of 21 surgical samples of high-grade astrocytoma and glioblastoma but not normal brain tissues expressed IL-4R as assessed by reverse transcriptase PCR. We further demonstrate that human malignant astrocytoma cell lines express high-affinity IL-4R. Using a chimeric protein composed of circularly permuted IL-4 and a truncated form of Pseudomonas exotoxin A, we observed that this toxin IL4(38-37)-PE38KDEL) is highly cytotoxic to IL-4R-bearing glioblastoma cells. Compared with a previously reported IL4-PE chimeric protein (IL-PE4E), IL4(38-37)-PE38KDEL bound with higher affinity and was 3-30-fold more cytotoxic to glioblastoma cell lines. Upon intrathecal administration in monkeys, high cerebrospinal fluid IL4(38-37)-PE38KDEL levels were achieved using 2- and 6-microg/kg doses without any central nervous system or other abnormalities. IL4(38-37)-PE38KDEL levels were not detectable in the serum of any monkey studied. When IL4(38-37)-PE38KDEL was injected into the right frontal cortex of rats, localized necrosis was observed at 1000-ng/ml doses but not at < or = 100-ng/ml doses. We conclude that by localized administration, nontoxic levels of IL4(38-37)-PE38KDEL can be achieved, which may have significant cytotoxic activity against malignant astrocytoma.
目前缺乏针对恶性胶质母细胞瘤/星形细胞瘤的有效治疗方法。我们已经在人类恶性星形细胞瘤中鉴定出白细胞介素-4受体（IL-4R）。我们证明，通过逆转录酶PCR评估，21例高级别星形细胞瘤和胶质母细胞瘤手术样本中有16例表达IL-4R，而正常脑组织不表达。我们进一步证明，人类恶性星形细胞瘤细胞系表达高亲和力的IL-4R。使用由环状排列的IL-4和截短形式的铜绿假单胞菌外毒素A组成的嵌合蛋白，我们观察到这种毒素IL4(38-37)-PE38KDEL对表达IL-4R的胶质母细胞瘤细胞具有高度细胞毒性。与先前报道的IL4-PE嵌合蛋白（IL-PE4E）相比，IL4(38-37)-PE38KDEL结合亲和力更高，对胶质母细胞瘤细胞系的细胞毒性高3至30倍。在猴子鞘内给药后，使用2和6μg/kg剂量可达到高脑脊液IL4(38-37)-PE38KDEL水平，且无任何中枢神经系统或其他异常。在任何研究的猴子血清中均未检测到IL4(38-37)-PE38KDEL水平。当将IL4(38-37)-PE38KDEL注入大鼠右额叶皮层时，在1000 ng/ml剂量下观察到局部坏死，而在≤100 ng/ml剂量下未观察到。我们得出结论，通过局部给药，可以实现无毒水平的IL4(38-37)-PE38KDEL，其可能对恶性星形细胞瘤具有显著的细胞毒性活性。
