Epigenetic modulation of the retinoid X receptor alpha by green tea in the azoxymethane-Apc Min/+ mouse model of intestinal cancer.

We investigated the possible mechanisms of inhibition of colorectal carcinogenesis by green tea (GT) in azoxymethane-treated (AOM) Apc(Min/+) mice. Mice received water or a 0.6% (w/v) solution of GT as the only source of beverage.

Interleukin-6 and cachexia in ApcMin/+ mice.

The Apc(Min/+) mouse has a mutation in the Apc tumor suppressor gene and develops intestinal polyps, beginning at 4 wk of age. This mouse develops cachexia by 6 mo, characterized by significant loss of muscle and fat tissue. The purpose of the present study was to determine the role of circulating interleukin-6 (IL-6) and the polyp burden for the development of cachexia in Apc(Min/+) mice.

Green tea selectively targets initial stages of intestinal carcinogenesis in the AOM-ApcMin mouse model.

One of the liabilities of the Apc(Min) mouse as a model for colon cancer is its lack of a robust tumor response in the large bowel. In our protocol, we treated the Apc(Min) mouse with azoxymethane, a colon-selective carcinogen. This protocol induced a 4-fold increase in the number of colon tumors.

Chemopreventive effects of Khaya senegalensis bark extract on human colorectal cancer.

An extract of the bark of Khaya senegalensis is commonly used in African traditional medicine for pain and inflammation. Khaya senegalensis bark extract (KSBE) was hypothesized to contain inhibitors of the cyclooxygenase-2 (COX-2) gene and to be useful in the prevention and treatment of colorectal cancer. The diphenyl-2-picrylhydrazyl (DPPH)- free radical activity and the total phenolic content of KSBE were measured, followed by an investigation of cell growth inhibition, COX and prostaglandin E 2 (PGE2) suppression, as well as apoptosis by Western blot analysis and ELISA.

Green tea polyphenol (-)-epigallocatechin-3-gallate inhibits cyclooxygenase-2 expression in colon carcinogenesis.

Tea, one of the most widely consumed beverages worldwide, has been shown to have anti-cancer activity in various cancers including colon cancer. It has been demonstrated that overexpression of the inducible isoform of cyclooxygenase (COX-2) occurs during colon tumorigenesis and inhibition of COX-2 by non-steroidal anti-inflammatory drugs (NSAIDs) is chemopreventive. To determine whether the anti-cancer effect associated with green tea impacted COX-2 expression levels, human colorectal cancer cell lines HT-29 and HCA-7, were treated with (-)-epigallocatechin-3-gallate (EGCG), the most abundant and effective polyphenol of green tea.

Modulation of aberrant crypt foci and apoptosis by dietary herbal supplements (quercetin, curcumin, silymarin, ginseng and rutin).

It is estimated that one-third of Americans use dietary herbal supplements on a regular basis. Diets rich in bioactive phytochemicals are associated with reduced risk of certain cancers, notably, colon cancer. Herbal supplements have not been directly tested as sources of bioactive cancer preventives.

The PPAR{gamma} Pro12Ala polymorphism and risk for incident sporadic colorectal adenomas.

Peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear hormone receptor superfamily initially shown to be a key regulator of fat cell differentiation, can inhibit cell growth and induce apoptosis in colon cell lines. There are heterozygous loss of function mutations in the gene encoding PPARgamma in tumors from approximately 10% of human colon cancer patients. A common structural polymorphism has been detected in the PPARgamma gene at codon 12 (Pro12Ala).

Identification and characterization of a phorbol ester-responsive element in the murine 8S-lipoxygenase gene.

Murine 8S-lipoxygenase (8S-LOX) is a 12-O-tetradecanoylphorbol-13-acetate (TPA)-inducible lipoxygenase. That is, it is not detected in normal mouse skin, however, a significant increase in expression is detected in the skin of TPA promotion-sensitive strains of mice after TPA treatment. In this study, we found TPA-induced 8S-LOX mRNA expression is a result of increased transcription in SSIN primary keratinocytes and further investigated transcriptional regulation of 8S-LOX expression by cloning its promoter.

Characterization of the rat cytoplasmic C1-tetrahydrofolate synthase gene and analysis of its expression in liver regeneration and fetal development.

The eukaryotic trifunctional enzyme, C(1)-tetrahydrofolate (THF) synthase, interconverts folic acid derivatives between various oxidation states and is critical for normal cellular function, growth, and differentiation. Using a rat C(1)-THF synthase cDNA and synthetic oligonucleotides, the rat C(1)-THF synthase gene was isolated and characterized. The gene consists of 28 exons and spans 67.