Cancer chemoprevention mechanisms

LIN J K, CHEN Y c, HUANG Y T and LiN-SHiAU s Y (1997) Snppression of protein kinase C and nuclear oncogene expression as possible molecnlar mechanisms of cancer chemoprevention by apigenin and curciunin Journal Cell Biochemistry Suppl. 28-9, 39-48. 

Several studies have shown the ability of DNMT inhibitors to prevent cancer using different pathways [101-104]. Genistein demonstrated cancer chemopreventive activities in animal models [105]. It has been studied in different cancer cell lines and inhibition of cancer cell growth has been shown [106]. But several mechanisms, such as antihormonal effects, are discussed to explain this activity and the exact contribution of DNMT inhibition to in-vivo activity in cancer chemoprevention remains to be determined. 

Hauser, A.-T. and Jung, M. (2008) Targeting Epigenetic Mechanisms Potential of Natural Products in Cancer Chemoprevention. Planta Medica (in press). 

Gerhauser C, Klimo K, Heiss E, Neumann I, Gamal-Eldeen A, Knauft J, Liu GY, Sitthimonchai S, Frank N. 2003. Mechanism-based in vitro screening of potential cancer chemopreventive agents. Mutat Res 523-524 163-172. 

Cancer prevention is now one of the most urgent projects in public health. It is evident that an understanding of the mechanisms of the carcinogenesis process is essential for cancer chemoprevention. Most cancer prevention research is based on the concept of multistage carcinogenesis initiation —> promotion — progression [2-4] [Fig. (1)]. Cancer chemoprevention is defined as the use of specific natural and... 

Marks F, Ftirstenberger G, Heinzelmann T, Mtiller-Decker K. Mechanisms in tumor promotions guidance for risk assessment and cancer chemoprevention. Toxicol Letts 1995 82/83 907-17. 

Although flavanols, also called catechins, seem to be widely distributed in plants, they are rich only in tea leaves, where catechins may contribute up to 30% of dry leaf weight. The antioxidative and antitumor properties of green and black teas and their tea polyphenols are extensively studied. It seems that tea polyphenols are important not only for plants but also for humans. Therefore, this brief review will discuss the current data with a particular emphasis on the effects of tea polyphenols on the cellular oxidative stress and cancer chemopreventive properties. The action mechanisms of several phytopolyphenols on cancer chemoprevention will be elaborated. 

In 1966-1967, we demonstrated that treatment of rats with certain polycyclic hydrocarbons or aromatic azo derivatives stimulated the in vitro and in vivo metabolism of 7,12-dimethylbenz[a]anthracene (9,10), which provided a mechanistic explanation for earlier research indicating an inhibitory effect of these compounds on 7,12-dimethylbenz[a]anthracene-induced mammary cancer and adrenal toxicity in rats (11-15). These early studies on mechanisms of inhibition of azo dye and polycyclic hydrocarbon carcinogenesis as well as subsequent studies suggested that induction of carcinogen detoxifying enzymes may be a useful strategy for cancer chemoprevention [reviewed in Refs. (16-18)]. 

BIOCHEMICAL AND MOLECULAR MECHANISMS OF CANCER CHEMOPREVENTION BY TEA AND TEA POLYPHENOLS... 

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