chrysin and Cell-Transformation--Neoplastic

Colorectal cancer is one of the primary causes of cancer-related mortality worldwide. The tumor microenvironment contains growth factors; inflammatory chemokines, matrix metalloproteinases, and pro-oxidants leading to cancer development and progression. Phytochemicals have been used as the main source of anti-cancer agents. Accordingly, the effect of two natural flavonoids (Chrysin and Daidzein) was investigated on the level of amphiregulin (AREG), chemokine ligand (CXCL1), and matrix metalloproteinase-9 (MMP-9) in 1, 2-dimethylhydrazine dihydrochloride (DMH) induced colorectal cancer. Rats were injected by DMH (40 mg/kg/week S.C.) for 16 weeks concomitantly with 2% dextran sodium sulfate (DSS) in drinking water for three cycles. Rats were orally treated with chrysin (125 and 250 mg/kg) and daidzein (5 and10 mg/kg) three times/week for the last 8 weeks. DMH + DSS group showed a significant (P < 0.05) increase in the levels of AREG (2386 ± 18 vs 1377 ± 10 pg/ml), CXCL1 (18 ± 0.9 vs 6 ± 0.83 g/ml), MMP-9 (1355 ± 88 vs 452 ± 7 pg/ml) compared to normal rats. These findings were associated with a potent antioxidant activity against cytochrome P450 2E1; (CYP2E1). Histopathological findings of the DMH + DSS group showed focal hyperplasia of the mucosa lining overlying crypts with moderate inflammation, dysplastic epithelial cells, and loss of goblet cells. Chrysin and daidzein treatment significantly (P < 0.05) restored the biochemical alterations and reverted histopathological findings near to the normal status. Moreover, chrysin and daidzein exerted anticancer activity against SW620 cells that were associated with decreased the protein expression of p-ERK/ERK and p-AKT/AKT. In conclusion, this study highlighted the potential anticancer role of chrysin and daidzein in the treatment of colon cancer.

Topics: 1,2-Dimethylhydrazine; Amphiregulin; Animals; Antineoplastic Agents, Phytogenic; Cell Line, Tumor; Cell Transformation, Neoplastic; Chemokine CXCL1; Colon; Colorectal Neoplasms; Cytochrome P-450 CYP2E1; Dextran Sulfate; Disease Models, Animal; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Humans; Isoflavones; Male; Matrix Metalloproteinase 9; Oxidative Stress; Proto-Oncogene Proteins c-akt; Rats; Signal Transduction

Mitogen- and stress-activated kinase 1 (MSK1) is a nuclear serine/threonine protein kinase that acts downstream of both extracellular signal-regulated kinases and p38 mitogen-activated protein kinase in response to stress or mitogenic extracellular stimuli. Increasing evidence has shown that MSK1 is closely associated with malignant transformation and cancer development. MSK1 should be an effective target for cancer chemoprevention and chemotherapy. However, very few MSK1 inhibitors, especially natural compounds, have been reported. We used virtual screening of a natural products database and the active conformation of the C-terminal kinase domain of MSK1 (PDB id 3KN) as the receptor structure to identify chrysin and its derivative, compound 69407, as inhibitors of MSK1. Compared with chrysin, compound 69407 more strongly inhibited proliferation and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced neoplastic transformation of JB6 P+ cells with lower cytotoxicity. Western blot data demonstrated that compound 69407 suppressed phosphorylation of the MSK1 downstream effector histone H3 in intact cells. Knocking down the expression of MSK1 effectively reduced the sensitivity of JB6 P+ cells to compound 69407. Moreover, topical treatment with compound 69407 before TPA application significantly reduced papilloma development in terms of number and size in a two-stage mouse skin carcinogenesis model. The reduction in papilloma development was accompanied by the inhibition of histone H3 phosphorylation at Ser10 in tumors extracted from mouse skin. The results indicated that compound 69407 exerts inhibitory effects on skin tumorigenesis by directly binding with MSK1 and attenuates the MSK1/histone H3 signaling pathway, which makes it an ideal chemopreventive agent against skin cancer.

Topics: Animals; Anticarcinogenic Agents; Cell Cycle; Cell Proliferation; Cell Transformation, Neoplastic; Flavones; Flavonoids; Histones; Male; Mice; p38 Mitogen-Activated Protein Kinases; Papilloma; Phenethylamines; Phosphorylation; Protein Structure, Tertiary; Ribosomal Protein S6 Kinases, 90-kDa; Signal Transduction; Skin; Skin Neoplasms; Tetradecanoylphorbol Acetate

Flavonoids possess strong anti-oxidant and cancer chemopreventive activities. Chrysin (5,7-dihydroxyflavone) occurs naturally in many plants, honey, and propolis. In vitro, chrysin acts as a general anti-oxidant, causes cell cycle arrest and promotes cell death. However, the mechanism by which chrysin inhibits cancer cell growth and the subcellular pathways activated remains poorly understood. Effect of dietary supplementation with chrysin on proliferation and apoptosis during diethylnitrosamine (DEN)-induced early hepatocarcinogenesis was investigated in male Wistar rats. To induce hepatocarcinogenesis, rats were given DEN injections (i.p., 200 mg/kg) three times at a 15 day interval. An oral dose of chrysin (250 mg/kg bodyweight) was given three times weekly for 3 weeks, commencing 1 week after the last dose of DEN. Changes in the mRNA expression of COX-2, NFkB p65, p53, Bcl-xL and β-arrestin-2 were assessed by quantitative real-time PCR. Changes in the protein levels were measured by western blotting. Chrysin administration significantly (P<0.001) reduced the number and size of nodules formed. Also, a significant (P<0.01) reduction in serum activities of AST, ALT, ALP, LDH and γGT was noticed. Expression of COX-2 and NFkB p65 was significantly reduced whereas that of p53, Bax and caspase 3 increased at the mRNA and protein levels. Likewise, a decrease in levels of β-arrestin and the anti-apoptotic marker Bcl-xL was also noted. These findings suggest that chrysin exerts global hepato-protective effect and its chemopreventive activity is associated with p53-mediated apoptosis during early hepatocarcinogenesis.

Topics: Animals; Anticarcinogenic Agents; Apoptosis; Apoptosis Regulatory Proteins; Arrestins; beta-Arrestin 2; beta-Arrestins; Biomarkers; Body Weight; Cell Cycle Proteins; Cell Proliferation; Cell Transformation, Neoplastic; Cyclooxygenase 2; Diethylnitrosamine; Flavonoids; Glutathione S-Transferase pi; Liver; Liver Neoplasms, Experimental; Male; Organ Size; Precancerous Conditions; Rats; Rats, Wistar; Time Factors; Transcription Factor RelA; Tumor Suppressor Protein p53