Effect Of Quercetin On Proliferation And Invasion Of Colon Carcinoma LOVO Cells And The Expression Level Of Carcinoembryonic Antigen

Backgroup and purposeThe transforming growth factor-β (TGF-β) signaling pathway is a keyplayer in metazoan biology,and its misregulation can result in tumordevelopment.TGFβ also modulates processes such as cell growth, invasion,immune regulation, and microenvironment modification that cancer cellsmay exploit to their advantage.As a tumor marker for colorectal cancers,carcinoembryonic antigen (CEA) enhances the metastatic potential of cancercells. CEA functions as an intercellular adhesion molecule and isupregulated in a wide variety of human cancers.The expression of CEA is asa prognostic indicator, and its role in surveillance and responseassessment.Transforming growth factor-β (TGF-β) signaling regulates bothtumor growth and metastasis, and also contributes to the stimulation of CEAtranscription and secretion in colorectal cancer cells.Quercetin is a naturalflavonol-type flavonoid ubiquitously presents in various vegetables andfruits, such as tea， o nion, apples，penthorum chinense pursh and so on. It plays the roles of anti-inflammatory, antioxidative and vasodilating effects,and has been proposed to be a naturally potential anti-cancer agent in theU.S.and Europe.Our studys offer a new therapeutic drug to inhibit coloncarcinoma LOVO cells proliferation， metastasis and the expression of CEAby using quercetin, paving the way for a better understanding of the TGF-βsignaling and therapeutic potential of quercetin in cancers.Methods(Ⅰ) Quercetin inhibits on proliferation in LOVO cells throughTGF-β1/smad3/c-myc signaling pathway1、 Lovo cells treated with5ng/ml doses of TGF-β1by one week wereas models of the experiments.The experiments were divided into fourgroups:control group(C group)；TGF-β1treatment group(T group)；TGF-β1and Quercetin treatment group(TQ group)；Quercetin treatment group(Qgroup). C group is normal LOVO cells. LOVO cells treated with5ng/mldoses of TGF-β1by one week were T group. After treated with5ng/ml dosesof TGF-β1by one week, LOVO cells were treated with20umol/L doses ofQuercetin were TQ group. LOVO cells only treated with20umol/L doses ofQuercetin were Q group.2、The effect of Quercetin and TGF-β1on the LOVO cellsproliferation were observed by MTT and Clone formation assays.3、The effect of Quercetin and TGF-β1on the expressions of smad3andc-myc in the LOVO cells were observed by IHC (Immunohistochemistry), RT-PCR (Reversible transcription PCR) and WB (Western Blot) assayrespectively.(Ⅱ) Effect of Quercetin on proliferation and invasion of coloncarcinoma LOVO cells and the expression level of carcinoembryonicantigen1、 The experiments were divided into two groups:Control group andQuercetin treatment groups. Control group is normal LOVO cells. LOVOcells treated with different doses of Quercetin were Quercetin treatmentgroups.2、 After treated with Quercetin， LOVO cells were determined for celladhesion and invasion of LOVO cell by Tumor cell adhering to the vascularendothelial cell assay and Transwell chamber invasion assay.3、 The expression level of CEA gene in LOVO cells treated withquercetin were measured by IF (Immunofluorescence)、 RT-PCR(Reversible transcription PCR) and WB (Western Blot).Results(Ⅰ) Quercetin inhibits on proliferation in LOVO cells throughTGF-β1/smad3/c-myc signaling pathway1、When compared with C group, the proliferation and the expression ofsmad3and c-myc in T group were weaker than C group(P<0.05)，butstronger in Q group and TQ group(P<0.05).2、When TQ group compared with Q group, the proliferation and the expression of c-myc in TQ group were weaker than Q group(P<0.05).Whilethe protein expression of smad3has no significant difference between thetwo groups(P>0.05).(Ⅱ) Effect of Quercetin on proliferation and invasion of coloncarcinoma LOVO cells and the expression level of carcinoembryonicantigen1、When compared with Control group, the ability of LOVO cellsadhering to the vascular endothelial cells in Quercetin group were strongerthan Control group,while the invasion ability were weaker than Controlgroup(P<0.05).2、 When compared with Control group,the mRNA and proteinexpression levels of CEA in Quercetin group were weaker than Controlgroup(P<0.05).Conclusion1、 The proliferation of LOVO cells and the expression of smad3andc-myc of LOVO cells were promoted by TGF-β1.2、 Quercetin can inhibit the proliferation of the LOVO cells throughdown-regulating the expression of c-myc by inhibiting theTGF-β1/smad3/c-myc signaling pathway.3、 Quercetin can improve the ability of LOVO cells adhering to thevascular endothelial cells and reduce the invasion ability of LOVO cells.4、 Quercetin can inhibit the protein and mRNA expression levels of CEA gene in LOVO cells in dose-dependent.