Mechanism Of Curcumin In Inhibiting The Growth Of Pancreatic Carcinoma Cells SW1990

BackgroundCurcumin is an acidic polyphenols, for two ketone compounds, widely present in the roots of manyplants.such as turmeric, Curcuma zedoaria, curcuma aromatica, calamus and so on. Its molecular formula isC21H20O6, relative molecular mass of368.37, orange yellow crystalline powder. Turmeric has been used astraditional medicine for hundreds of years, mainly for the treatment of trauma, liver disease (especiallyjaundice), detoxification, joint pain (arthritis) and so on. Commonly used in traditional Chinese medicineturmeric comes from the ginger family plant turmeric (curcuma longa L) roots, with expelling gas line,Sanjie analgesic effect, in1842for the first time isolated from yellow substance curcumin, curcumin[curcumin, cur,1,7-bis (4-hydroxy-3-methoxy) phenyl1,6-heptadiene-3,5-dione] is the main activeingredient. In1910,The chemical structure of curcumin was first identified. Numerous studies in recentyears found that curcumin has antioxidant, anti-inflammatory and anti-cancer activity of a wide range ofbiological, for the treatment of skin diseases, diabetes, rheumatoid arthritis and multiple cancer.Wnt gene was the first discovered by the two combinations come that early Drosophila wingless(wg) gene and the mouse Int-1genes. Nematodes from both human Wnt genes has been cloned19kinds ofWnt gene family members, they are secreted proteins encoded by the amino acids350-400, wherein thehalf24comprises conservative histidine residues hazy, during development of the animals is required fordifferentiation. Intracellular Wnt signaling pathway is a class of signal transduction pathways to stimulategrowth because Wnt protein starting protein named. Wnt signal transduction pathways, includingsignaling protein (Wnt), transmembrane receptors (Frizzled), cytoplasmic and nuclear proteins such astranscription factors. The core of the canonical Wnt pathway is cytoplasmic β-catenin stability, when lowlevels of β-catenin,, Wnt pathway closed; Conversely, Wnt pathway open. Intracellular levels ofβ-catenin by two factors function to regulate competition: the degradation of proteins, including GSK-3β,Axin, APC, so that a low level of β-catenin, thereby closing the Wnt pathway; antagonistic proteins,including CK1α, Dsh, GSK-3β binding proteins, antagonistic role of protein degradation, so that elevatedlevels of β-catenin. Due to abnormal activation of the Wnt signaling pathway with a variety of tumors, ormetastases, Wnt signaling pathway has been associated for many studies, the mechanism of tumorigenesis in its development has achieved some results, but in the Wnt signaling pathway components designed toprevent Find areas targeted treatment of cancer requires further exploration.PurposesTo investigate the effect of different concentrations of curcumin on inhibiting the proliferation ofhuman pancreatic cancer cells SW1990in vitro, and then to explore the possible molecular mechanism ofinhibiting the proliferation and inducing apoptosis of pancreatic cancer cells.MethodsMTT assay with different concentrations of curcumin (20,40,60,80,100μmol/L) for inhibition ofSW1990human pancreatic cancer cell proliferation, apoptosis rate by flow cytometry analysis of cells,curcumin was detected by WesternBlot effect on β-catenin protein expression was detected bysemi-quantitative PCR target genes VEGF, cyclinD1and c-myc in different concentrations of curcuminexpression changes. Experimental observation of molecular interactions BIAcore application mode ofaction of curcumin, the virtual molecular docking binding sites found curcumin with a Wnt protein region.ResultsBased on our study of molecular interactions BIAcore experiments, curcumin Dvl2by binding toa region to promote the formation of β-catenin degradation complex, reducing the intracellular levels ofβ-catenin thereby inhibiting the Wnt signal transduction pathway. Further, the molecular dockingsimulation experiments, we found that curcumin molecules closely Dvl2-PDZ interaction region.Experimental study of curcumin by inhibiting Wnt signaling pathway in the biological behavior of tumorcells found: different concentrations of curcumin on pancreatic cancer SW1990cells for48hours, cellproliferation inhibition rate rise. The higher the concentration, the more obvious proliferation inhibitionrate and a dose-response relationship (P <0.05).②detected by flow cytometry after48hours of curcuminin pancreatic cancer cells, the percentage of apoptotic cells increased with increasing concentrations of thedrug, a dose-response relationship (P <0.05).③Western blot Show: pancreatic cancer cells by curcuminSW1990cells, cytoplasmic β-catenin protein in the experimental group after48h less than the controlgroup. In SW1990cells, in addition to20μmol/L concentration group, other concentrations with thecontrol group were statistically significant (P <0.05). Drug concentration, the more cytoplasmic β-catenin less protein in a dose-dependent manner (r=-0.96, P <0.05).④semi-quantitative PCR Wnt downstream c-myc, VEGF, cyclinD1mRNA expression level was significantly reduced compared with thenegative control group (P <0.05), in a dose-effect relationship. Based on our study of molecularinteractions BIAcore experiments found that curcumin can promote the degradation of complex formation,so that the intracellular β-catenin protein can be degraded after phosphorylation. Virtual molecular dockingshowed that curcumin can be combined with a region DVL2-PDZ promote β-catenin degradation complexformation, reduced intracellular levels of β-catenin thereby inhibiting the Wnt signal transduction pathway.ConclusionsOur research data supports that curcumin can inhibit proliferation of pancreatic cancer cellsSW1990and induce apoptosis. Curcumin is a Wnt signaling inhibitor that competitively binds toDVL2-PDZ domain, contributing to the regulation of cellular signaling network that helps to explaincurcumin’s anticancer effects.