Antitumor activity of natural-type human tumor necrosis factor on experimental brain tumors in rats

Repeated peripheral administrations of CpG oligodeoxynucleotides lead to sustained CNS immune activation

Bacterial DNA containing CpG motifs activates cells of the innate immune system. In this study, we examined the effects of multiple peripheral bacterial DNA-mediated CNS innate immune stimulation. To study this issue, we repeatedly peripherally administered synthetic CpG-oligodeoxynucleotides (CpG-ODN) and assayed effects on CNS-associated TNF-alpha (TNFalpha) and C1q mRNA levels. We for the first time accounted for frequency of CpG-ODN administration and time kinetics of mRNA expression. We were able show that multiple intraperitoneal CpG-ODN administrations have a sustainable effect on immune effectors of the brain and stimulate TNFalpha mRNA secretion even up to 7 days after the last CpG-ODN application. This could on the one hand indicate a depot effect after multiple peripheral CpG-ODN administrations, however, it could also indicate that the cell producing TNFalpha mRNA remains activated for the indicated time period. Furthermore, elevated mRNA levels of C1q were observed, possibly indicating microglial activation after multiple peripheral bacterial DNA administrations. In this study, we have correlated frequency of CpG-ODN administrations with CNS-associated TNFalpha mRNA levels and show that multiple peripheral administrations of CpG-ODN lead to a sustained level of a Th1-associated cytokine in the brain. These findings indicate that the repeated peripherial administration of CpG oligodeoxynucleotides offer a therapeutical possibility for CNS-associated infections and tumors.

Research progress in the last quarter of the 20th century at the University of Tokyo and Tokyo Women's Medical University

Professor Keiji Sano described the history of neurosurgery in Japan until 1975. After World War II, not only neurosurgery but all fields of medicine were devastated in Japan. Professor Sano contributed greatly to the reform and modernization of neurosurgery during that very difficult era in Japan. He performed much research by himself and also as a leader of research groups on stereotactic and functional neurosurgery, cerebrovascular diseases, head injuries, and brain tumors. He organized the Fifth International Congress of Neurological Surgery in Tokyo in 1973. I succeeded in the chairmanship of the Department of Neurosurgery of the University of Tokyo in 1981. We have performed research on the treatment of brain tumors and cerebrovascular diseases. To obtain the best results for brain tumor treatment, we have introduced several new radiotherapeutic methods, such as the gamma knife, heavy-particle irradiation, and the photon radiosurgery system. To improve surgical treatment, we have energetically engaged in medical engineering research on computer-assisted surgical systems (intraoperative monitoring and navigation systems). We have also performed much research on chemotherapy and immunotherapy. In the field of cerebrovascular diseases, the main research projects have been focused on the mechanism and treatment of vasospasm and brain edema after subarachnoid hemorrhage. I summarize the results of our research performed in the Department of Neurosurgery of the University of Tokyo until 1992 and at Tokyo Women's Medical University after 1992, in the last quarter of the 20th century.

Pulse treatment of human vascular endothelial cells with high doses of tumor necrosis factor and interferon-gamma results in simultaneous synergistic and reversible effects on proliferation and morphology

Regional administration of high doses of tumor necrosis factor (TNF), interferon gamma (IFNgamma) and melphalan to patients with advanced cancers of the limbs, results in rapid and specific tumor necrosis, while the normal adjacent tissues remain unaffected. The tumor vasculature is selectively destroyed by this treatment, and neovascular endothelial cells appear to be an early and specific target of TNF and IFNgamma. To further understand some of the cellular events underlying these in vivo effects, we have investigated the response of human macro- and microvascular endothelial cells in vitro, after exposure to high doses of TNF and IFNgamma (up to 40 x 10(3) U/ml each). TNF and IFNgamma synergistically inhibited endothelial-cell proliferation by up to 80% after 72 hr of treatment. Achievement of synergy required the simultaneous presence of both cytokines. A cytokine pulse as short as 30 min was sufficient to induce maximal growth inhibition measured after 48 hr. Both cytokines also induced progressive and dose-dependent elongation of the endothelial-cell morphology. The effects on endothelial-cell proliferation and morphology were reversible upon removal of the cytokines. Moreover, replating of treated cells onto a fresh substrate immediately resulted in re-acquisition of their normal shape. In contrast to the effect on cell proliferation, there was little or no effect on the rate of endothelial-cell apoptosis. The presented data extend reports on the effects of TNF and IFNgamma on human endothelial cells in vitro, and suggest that the in vivo disruption of the tumor vasculature caused by high doses of TNF and IFNgamma is not due to a direct cytotoxic effect on endothelial cells but occurs through an indirect mechanism.

Morphological change in tumor endothelial cells induced by natural-type human tumor necrosis factor

The effects of natural-type human tumor necrosis factor (nh-TNF) on tumor endothelial cells of experimental brain tumors were investigated electron microscopically. Tumor vessels with hypertrophic endothelial cells were observed 12 and 24 hr after an intralesional administration of 5,000 U of nh-TNF. Increased biosynthetic organelles such as the Golgi complex and rough endoplasmic reticulum were evident in the plump cytoplasms. These endothelial cells resembled those in high endothelial venules (HEV) functionally characterized by the high permeability of leukocytes. In addition, close interactions between these endothelial cells and leukocytes were observed. Our findings indicated that nh-TNF could promote the morphological change in tumor endothelial cells into HEV-like cells.