Tumors necrosis, mechanism

Cytokines, eg, interferons, interleukins, tumor necrosis factor (TNF), and certain growth factors, could have antitumor activity directiy, or may modulate cellular mechanisms of antitumor activity (2). Cytokines may be used to influence the proliferation and differentiation of T-ceUs, B-ceUs, macrophage—monocyte, myeloid, or other hematopoietic cells. Alternatively, the induction of interferon release may represent an important approach for synthetic—medicinal chemistry, to search for effective antiinflammatory and antifibrotic agents. Inducers of interferon release may also be useful for lepromatous leprosy and chronic granulomatous disease. The potential cytokine and cytokine-related therapeutic approaches to treatment of disease are summarized in Table 4. A combination of cytokines is a feasible modaUty for treatment of immunologically related diseases however, there are dangers inherent in such an approach, as shown by the induction of lethal disserninated intravascular coagulation in mice adrninistered TNF-a and IFN-y. 

Fig. 4.4 Simplified hypothesis of the mechanism of gpI20-induced dorsal root gangUon (DRG) neurotoxicity. CXCR4 binding on Schwann cells by SDF-Ia or gpI20 results in the release of RANTES, which induces tumor necrosis factor (TNF)-a production by DRG neurons, and subsequent TNFRl-mediated neurotoxicity in an autocrine/paracrine fashion. Reproduced with permission of John Wiley Sons, Inc. (Keswani et al. 2003b)...

Larrick, J.W. and Wright, S.C. (1990). Cytotoxic mechanism of tumor necrosis factor alpha. FASEB J. 4, 3215-3223. 

B24. Beutler, B., Krochin, N., Milsark, J. W Luedke, C., and Cerami, A., Control of cachectin (tumor necrosis factor) synthesis mechanisms of endotoxin resistance. Science 232, 977-980 (1986). 

D19. Dinarello, C. A., Okusawa, S., and Gelfland, J. A., Interleukin-1 induces a shock-like state in rabbits Synergism with tumor necrosis factor and the effect of cyclooxygenase inhibition. In Molecular and Cellular Mechanisms of Septic Shock. Alan R. Liss, New York, 243-263... 

Drapier,J.C., Wietzerbin, J. and Hibbs, J.B. Jr (1988) Interferon-gamma and tumor necrosis factor induce the L-arginine-dependent cytotoxic effector mechanism in murine macrophages. European Journal of Immunology 18,1587-1592. 

Fas ligand and interleukin-ip), the neurotransmitter glutamate and thrombin. Like tumor necrosis factor (TNF) receptors, Fas is coupled to downstream death effector proteins that ultimately induce caspase activation (Ch. 22). Fas and TNF receptors recruit proteins called FADD and TRADD respectively FADD and TRADD then activate caspase-8, which, in turn, activates caspase-3 (Fig. 35-4). Calcium ion influx mediates neuronal apoptosis induced by glutamate receptor activation calcium induces mitochondrial membrane permeability transition pore opening, release of cytochrome c and caspase activation. Interestingly, in the absence of neurotrophic factors some neurotrophic factor receptors can activate apoptotic cascades, the low-affinity NGF receptor being one example of such a death receptor mechanism [23],... 

Kobayashi K, Takahashi N, Jimi E, Udagawa N, Takami M, Kotake S, Nakagawa N, Kinosaki M, Yamaguchi K, Shima N, Yasuda H, Morinaga T, Fligashio K, Martin TJ, Suda T (2000) Tumor necrosis factor alpha stimulates osteoclast differentiation by a mechanism independent of the ODF/RANKL-RANK interaction. J Exp Med 191 275-286... 

Mier, J.W. et al., Induction of circulating tumor necrosis factor (TNF-alpha) as the mechanism for the febrile response to interleukin-2 (IL-2) in cancer patients, J. Clin. Immunol., 8, 426, 1988. 

Matthews, N., Neale, M.L., Jackson, S.K., and Stark, J.M., 1987, Tumor cell kilhng by tumor necrosis factor inhibition by anearobiotic condition, free-radical scavengers and inhibitors of arachidonate metabolism. Immunology 62 153-155 Miller, M.G., Rodgers, A., and Cohen, G.M., 1986, Mechanisms oftoxicity of naphthoquinones to isolated hepatocytes. Biochem. Pharmacol. 35 1177-1184 Minko, T., Kopeckova, P., and Kopecek, J., 1999, Comparison ofthe anticancer effect of free and HPMA copolymer-bound adtiamycin in human ovarian carcinoma cells. Pharmaceut. Res. 16 986-996... 

Kim, M. Y., Linardic, C, Obeid, L., and Hannun, Y., 1991, Identification of sphingomyehn turnover as an effector mechanism for the achon of tumor necrosis factor alpha and gamma- interferon. Specific role in ceU differentiation. J. Biol. Chem. 266 484-489... 

There is a great deal of evidence that AmB can exert a number of effects directly on cells of the immune system, and particularly on macrophages to increase nonspecific defense mechanisms against pathogens and cancer cells. These mechanisms include the production of nitric oxide (NO) (32) and tumor necrosis factor alpha (TNF-a) (33), which could contribute to the antifungal and antiparasitic activity of AmB. However, excess TNF-a production could also be responsible for some of the side effects associated with AmB treatment, such as fever and chills. 

Anti-hepatitis B virus activity in vitro and in vivo was also found in wogonin and baicalein (Fig. 4), the major active constituents of the traditional Chinese medicine Scutellaria radix.More recently, Blach-Olszewska et al investigated the effect of baicalein and wogonin on two important mechanisms of innate immunity The secretion of cytokines, and the natural resistance of human leukocytes to viral infection. The results obtained indicate that these fiavonoids modulate cytokine production, that is they inhibit interferons-a and -y, and stimulate tumor necrosis factor-a and interleukin production. They also augment the resistance of peripheral blood leukocytes to the vesicular stomatitis virus. 

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