Cancer-activating Factors

The causes of DNA modifications can be very different. Next to carcinogenic chemicals, physical and biological factors are also important  

If the effectiveness of the immune system of the body is reduced, tumors are more often observable. Reduced immune activity is obviously connected with an increase in the prevalence of tumors. 

As mentioned above, we are in contact at all times with many natural and artificial agents that can lead to the development of tumors. For a healthy organism, the development of repair mechanisms to detect and repair changed DNA molecules is of great importance. Today a great number of such repair mechanisms are known. If the repair mechanisms are not able to recognize a DNA-modifica-tion, an uncontrolled cell growth can occur after a proliferation. 

For example, promoters can start the proliferation of an initiated cell. In contrast to the initiation stage, the promotion stage is reversible. If the promoter is removed before the proliferation starts, no autonomous (uncontrolled) ceU growth 

High-energy radiation is always capable of activating modifications of the DNA. Because of the numerous functional groups in the DNA, a great number of molecular modifications are conceivable. Radioactive radiation can activate breaks of the chromosomes and promote tumors by this way. 

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Chapter 7 outlines the basic mechanism and treatment of emesis, and in particular, that induced by chemotherapy of cancer. Finally, the chemistry, pharmacology and clinical applications of antagonists of the platelet-activating factor (PAF), an important mediator of many physiological and pathological conditions, are reviewed in Chapter 8. 

Branch RA, Chem HD, Adedoyin A, et al. The procarcinogen hypothesis for bladder cancer activities of individual drug metabolizing enzymes as risk factors. Pharmacogenetics 1995 5 S97-S102. 

A simple way to control transcription would be acetylation-deacetylation reactions carried out by the transcription factors themselves. Transcriptional regulators with histone acetylation-deacetylation activities have been identified. For example, the transcriptional repression and anti-cancer activity of a human DNA-binding protein (Sin3) has been ascribed to its histone deacetylase acnvity. ... 

The antiproliferative effect of Acetyl-N-Ser-Asp-Lys-Pro inhibitor of hematoporetic stem cell proliferation has been also reported [127]. Fibrinogen-like peptides have been reported to show anti cancer activity as well [128]. The identification of growth factors-like peptides with structures with common features of the known anticancer peptide (pS2), the pancreatic spasmolytic polypeptide (PSP) and frog skin peptides (spasmolysins) has been reported by Thim [129]. 

These data link asbestos to various forms of cancer. In the last several years, industry has made a big effort to eliminate asbestos ifom numerous products and asbestos is no longer an active factor. 

Ko HM, Seo KH, Han S J, Ahn KY, Choi IH, Koh GY, Lee HK, Ra MS, Im SY Nuclear factor kappaB dependency of platelet-activating factor-induced angiogenesis. Cancer Res 2002 62 1809-1814. Yamashiro S, Kamohara H, Yoshimura T MCP-1 is selectively expressed in the late phase by cytokine-stimulated human neutrophils TNF-alpha plays a role in maximal MCP-1 mRNA expression. J Leukoc Biol 1999 65 671-679. 

Abnormal DNA methylation patterns are a hallmark of most cancers. Dietary factors may influence the methylation process in different ways. First, methyl groups available for the formation of 5-adenosytmethionine (SAM) may be supplied from dietary factors. Second, dietary factors may modify the utilization of methyl groups by processes including shifts in DNA methyltransferase (Dnmt) activity, A third mechanism may relate to DNA demethylation activity. Finally, the DNA methylation patterns may influence the response to a bioactive food component [32],... 

Bottazzi, B., Colotta, F., Sica, A., Nobili, N., and Mantovani, A. (1990) A chemoattractant expressed in human sarcoma cells (tumor-derived chemotactic factor, TDCF) is identical to monocyte chemoattractant protein-1/monocyte chemotactic and activating factor (MCP-1/ MCAF). Int. J. Cancer 45,795-797. 

Anticancer activity of trace metals based on chelating or selected cytotoxic effects on neoplastic cells Pt and Ge inhibit cancer cell DNA synthesis and Se generally acts as a cancer prevention factor [51,61,65],... 

In the Second Expert Report of Food, Nutrition, Physical Activity and the Prevention of Cancer a Global Perspective (WCRF/ACRF 2007), which comprehensively reviewed the existing hterature on various cancer risk factors of diet and physical activity, vitamin Bg was not included in the summary of conclusions, which was based on the Panel s interpretation of exposures to potential risk factors for cancer. In their systematic hterature reviews, the Panel judged that the evidence for esophageal cancer and vitamin Bg, obtained from a single case-control study only, was stiU sparse and limited (WCRF/ACRF 2007). The report made no mention of the association between vitamin Bg and other cancers. 

Chitosan nanoparticles have also been formulated and evaluated for their anti-cancer potential. It has been reported that the smaller the particle size and higher the positive surface charge, the better its anti-cancer activity is. It showcases its action mainly by disruption of the membrane and induction of apoptosis [44]. The immunostimulatory potential of chitosan is also believed to be one of the factors alleviating its anti-cancer activity [45]. Chitosan nanoparticles have also been used as a drug carrier for delivery of anti-cancer drugs such as doxorubicin, paclitaxel, docetaxel and norcantharidin [46]. 

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