Study on the inhibition of chemical carcinogenesis of buccal mucosa with a macrophage activating factor

本研究旨在探讨一种新的巨噬细胞活化因子（GcMAF）对9，10-二甲基-1，2-苯并蒽（DMBA）诱发金黄地鼠颊囊癌的抑制作用及其对DMBA诱发肿瘤生长的抑制作用。GcMAF是N.Yamamoto等新近发现的一种糖蛋白，它以血清Gc蛋白（维生素D_3结合蛋白）为前体。获得的结果如下：1）将29只叙利亚仓鼠（5周龄）分成15只，给予GcMAF（100 μ g i. m.每周注射两次）和14只未给药，用1%DMBA-丙酮溶液每周3次涂于颊囊。因此，未施用GcMAF的组的所有仓鼠在施用DMBA后第9至第10周发生鳞状细胞癌，并在20周内死于肿瘤。另一方面，给予GcMAF的14只仓鼠中有2只没有产生肿瘤，其余12只仓鼠显示出肿瘤发展和生长的延迟并且存活 ...更多信息 直到实验期的第20周。2）未给予GcMAF的组中的5只荷瘤仓鼠显示出从第13周开始给予GcMAF的肿瘤生长抑制和体重减轻。GcMAF给药组中的4只荷瘤仓鼠从第13周开始停止GcMAF，显示肿瘤生长加速。3）在体外或体内用GcMAF处理仓鼠腹腔巨噬细胞，显示超氧化物生成增加，表明巨噬细胞活化。GcMAF激活的腹腔巨噬细胞对金黄地鼠肾BHK 21细胞和人口腔底癌KB细胞的杀伤作用明显高于未激活的巨噬细胞，提示GcMAF通过激活巨噬细胞抑制或延缓DMBA诱导的金黄地鼠颊囊癌的发生和肿瘤的生长，为GcMAF用于口腔癌的免疫治疗提供了可能。少

This study was designed to investigate the inhibitory effects of a new macrophage activating factor (GcMAF) on hamster buccal pouch carcinogenesis with 9,1O-dimethyl-1,2-benzanthracene (DMBA) and on the growth of DMBA-induced tumor. GcMAF newly discovered by N.Yamamoto is a glycoprotein derived from serum Gc protein (vitamin D_3-binding protein) as precursor. The results obtained were as follows.1)Twenty-nine Syrian hamsters (5 week-old) were divided into 15 with GcMAF administration (100 pg i.m. injection twice a week) and 14 without administration, and were painted a buccal pouch 3 times a week with 1% DMBA-acetone solution. Consequently, all hamsters of the group without GcMAF administration developed squamous cell carcinoma at the 9th to 10th week after DMBA application, and died of tumor within 20 weeks. On the other hand, two of 14 hamsters with GcMAF administration did not produce tumors, and the remaining 12 hamsters showed a delay of tumor development and growth and were alive … More until the 20th week of the experimental period. Also, their weight loss by tumor burden was slight.2)Five tumor-bearing hamsters in the group without GcMAF administration showed the inhibition of tumor growth and weight loss by starting GcMAF from the 13th week. Four tumor-bearing hamsters in the group with GcMAF administration showed acceleration of tumor growth by stopping GcMAF from the 13th week.3)Treatment of hamster peritoneal macrophages with GcMAF in vitro or in vivo demonstrated increased superoxide generation indicating the macrophage activation. The GcMAF-activated peritoneal macrophages revealed a significant cytocidal effect against hamster kidney BHK21 cells and human oral floor carcinoma KB cells as compared to non-activated macrophages.From these findings, it was indicated that GcMAF inhibited or delayed the DMBA-induced hamster buccal pouch carcinogenesis and tumor growth via macrophage activation, This investigation suggested the possibility of immunotherapy for oral cancer with GcMAF. Less