Tumor-inducing principle

DNA is thus implicated, but at first it was not known whether it was the DNA of the plant or of the bacterium. Many experiments strongly suggested the existence of a tumor-inducing principle (TIP) which was supposed to be released by the bacterial cells and initiate the change (transformation) in the plant cells. It now seems likely that the principle is indeed bacterial DNA. As has been shown, DNA migrates from the bacteria into the plant cells where it replicates itself and induces the formation of bacterial-specific proteins. It seems likely that this DNA is ultimately responsible for causing the tumors. 

Hemorrhage is the major risk of thrombolytic drugs there are some differences in risks between the various agents, and certain susceptibility factors can be identified. Transient hypotensive reactions have been described with all thrombolytic agents, but they are in principle reversible. Hypersensitivity reactions are most often seen in patients who have been treated with compounds derived from cultures of streptococci (streptokinase and anistreplase). Tumor-inducing effects have not been reported. 

Mohr, U., Althoff, J., Kinzel, V., Suss, R., and Volm, M., Melanoma regression induced by chalone a new tumor inhibiting principle acting in vivo. Nature (London) 220, 138-139 (1968). 

However, we finally found that the lectinlike component, the potential candidate for the tumor apoptosis-inducing principle, was unstable in its bioactivity from the fraction recovery process. Here, Pan et al. [14,15] (Figure 26.3) conducted a modified method for extraction from Meretrix lusoria and found that some epidioxysterol compounds [6] (Figure 26.4) showed strong antitumor/apoptosis-inducing ability. 

ZO024 Park, K. K., K. S. Chum, ]. M. Lee, S. S. Lee, and Y. ]. Surh. Inhibitory effects of [6]-gingerol, a major pungent principle of ginger, on phorbol ester-induced inflammation, epidermal ornithine decarboxylase activity and skin tumor promotion in ICR mice. Cancer Lett 1998 129(2) 139-144. 

Free-radical-induced reproductive cell death is the basis of radiotherapy, and it is obvious that the main problem of this approach to fight cancer is to target the ionizing radiation to the tumor in order to prevent damage to healthy tissue. This is a most difficult if not impossible task. Radiation modifiers that sensitize the tumor cells and protect healthy tissue are considered for improving treatment regimes in radiotherapy, and the underlying mechanistic principles are addressed. 

The primary clinical targets of immunotoxins are tumors, based on the principle that the MAb will target the toxin to the tumor cells and the highly toxic moiety will then kill the cancer cells. Examples of toxins are ricin, diphtheria toxin and abrin, which are all glycoproteins. Their toxicity is based on their ability to block protein synthesis at the ribosomal protein assembly site. They are normally extremely toxic and not suitable for therapeutic purposes because they induce liver and vascular toxicity, even at low dose levels. 

Applying the same principle, 2- and 4-pyridylethoxycarbonyl (2- and 4-Pyoc) structures can be sensitized by methylation of the pyridine nitrogen. Subsequent treatment with the weak base morpholine (pKa 8.3) in dichloromethane already induces fragmentation and the formerly protected amino group is liberated (Scheme 8). This method proved to be successful in the synthesis of acid- and base-sensitive O-glycopeptides with tumor-associated antigen structure. ... 

Jones, G. R., Ellis, R., and Frohn, M. J. (1981) Drug-induced interference with energy metabolism in the SI80 sarcoma a new principle in the production of selective tumor injury. Oncodev. Biol. Med. 2,155-164. 

Park, K.-K. Chun, K.-S., Lee. J.-M.. Lee, S.S., and Surh, Y.-J. (1998) Inhibitory Effects of [6]-Gingerol, a Major Pungent Principle of Ginger, on Phorbol Ester-Induced Inflammation, Epidermal Ornithine Decarboxylase Activity and Skin Tumor Promotion in ICR Mice, Cancer Lett. 129,139-144. 

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