The antitumor activity of highly purified tumor necrosis factor (TNF) was tested against eight kinds of murine tumor and five kinds of human tumor heterotransplanted into nude mice. Mice were treated by intravenous or intratumoral injection of TNF, commencing when the tumors were well established. TNF showed an excellent curative effect against all kinds of murine and human tumors tested. Meth A sarcoma, Colon 26, Ehrlich, sarcoma 180, MM 46, MH 134, B16 melanoma, and Lewis lung tumors transplanted into mice underwent tumor necrosis and regression following a single injection of TNF. Sometimes a complete cure was observed in Meth A sarcoma, sarcoma 180, Ehrlich, and MM 46 tumors. Human cancers, SEKI, HMV-I, KATO-III, MKN 45, or KB, heterotransplanted into nude mice, also exhibited tumor necrosis and regression in size following several intratumoral injections of TNF. A great difference in curative effects of TNF was observed in Meth A sarcomas between those transplanted into BALB/c nu/+ and into BALB/c nu/nu mice: following a single intravenous administration the effect was stronger in BALB/c nu/+ than in nu/nu mice. In contrast, tumor necrosis was almost the same in nu/+ and nu/nu mice following intratumoral administration. The present results thus indicate that TNF from mice had an antitumor activity against not only murine tumors but also human tumors. In addition to direct cytotoxicity against tumor cells, TNF induced a host-mediated factor which contributed to the antitumor effects.

The antitumor activities and capacity for tumor necrosis factor (TNF) production of traditional Chinese herbal preparations (Zhu-ling-tang, Xiao-chai-hu-tang), crude drugs (Polyporus, Hoelen, Bupleuri radix, Angelica radix, Cnidii rhizoma, Cinnamomum cortex), and Krestin (PSK) were investigated. These drugs were given to DDY mice in the drinking water before and after transplantation of Ehrlich tumors, and the development of the intradermally transplanted Ehrlich tumors and survival rate were observed. A good survival rate and sometimes a complete cure were found in the groups administered Bupleuri radix, Xiao-chai-hu-tang, Angelica radix, or Cinnamomum cortex, while the group given Hoelen showed poor results. To examine the capacity for TNF production these drugs were given to DDY mice PO as initial stimulating agents, to stimulate the reticuloendothelial system (RES) prior to lipopolysaccharide injection. The TNF activity was tested from the cytotoxicity against L cells. Significant differences in capacity for TNF production were observed among the drugs. Relatively high levels of TNF activity were noted in the groups given Angelica radix, Bupleuri radix, Cnidii rhizoma, or Cinnamomum cortex, very low activities in the groups given Xiao-chai-hu-tang, Zhu-ling-tang, or Krestin, and no TNF activities in the groups given Polyporus or Hoelen. The TNF capacity for production broadly paralleled the survival rate of the mice transplanted to Ehrlich tumors. Our findings suggest that one mechanism underlying the antitumor activities of these drugs is based on stimulation of the RES and is closely related of TNF production.

Mouse tumor necrosis factor (TNF) was purified from serum through a series of steps, and each step was monitored for L-cell cytotoxicity in vitro and tumor-necrotizing activity in vivo. The two activities copurified and could not be dissociated. Purified mouse TNF has a specific activity of 2.2 x 107 (L-cell assay in the absence of actinomycin D) and 1 ,ug causes necrosis of the standard TNF-sensitive sarcoma Meth A.

Good production of tumor necrosis factor (TNF) in the rabbit was obtained using Propionibacterium acnes IID 912 as a priming agent and subsequent administration of lipopolysaccharide. The physicochemical characteristics of rabbit TNF were very similar to those of murine TNF. The molecular weight of rabbit TNF was 39,000 as estimated by gel filtration, and 18,000 by SDS-PAGE. The isoelectric point was determined as pH 4.0 by isoelectric focusing. Rabbit TNF was stable within the pH range of 5.5 to 11.0, and was stable at 56 degrees C for 8 hr. It was digested by trypsin, pancreatic protease and elastase, but was resistant to neuraminidase. The amino acid sequence of rabbit TNF was determined as Ser-Ala-Ser-Arg-Ala-Leu- .... Monoclonal antibody against rabbit TNF completely inhibited both the in vivo and in vitro activity of rabbit TNF. However, this antibody could not inhibit the action of murine TNF. Antitumor activity of rabbit TNF was shown against murine and human cancer cells in vivo and in vitro, and rabbit TNF was also capable of distinguishing malignant cells from normal cells.

Summary Large differences in tumour necrosis factor (TNF) productive ability were observed among various strains of mice. DDY, CD-1, ICR and DBA/2 mice could produce a high titre of TNF activity, whereas Balb/c, C3H/HeJms and A/J mice produced a low titre of TNF activity. Administration of 200pg/mouse of LPS to some strains of mice, i.e. DDD and C57B1/6J resulted in good production of TNF. ICRnu/nu mice produced the highest TNF activity among the nude mice. Balb/cnu/nu and DDDnu/nu mice exhibited very low titres of TNF activity. Nude mice required a rather higher dose of the priming agent, Propionibacterium acnes, than heterozygote littermates. Although it is commonly accepted that dual stimulation is necessary for TNF production, TNF activity was detected without the priming agent in SD rats and Golden hamsters by single injection of LPS. In these animals, much higher TNF production was observed after Propionibacterium acnes treatment than after a single injection of LPS. Large differences in TNF productive ability also existed among strains of rats. Although all animals receiving priming agents revealed hyperplasia of reticuloendothelial system, the sensitivity of the animals to LPS is considered to be the most important factor in their TNF productive ability.