| Objective:Hepatocellular carcinoma is one of the most commonmalignant tumors which seriously threatens to human life. About90%ofcarcinoma of the liver are hepatocellular carcinoma. In each year, more than250thousands of new cases of HCC were reported around the world, amongwhich110000cases occurred in China. An effective means of clinicaltreatment of liver cancer include surgical resection and hepatic arteryembolization. However, early lesions are not easily noticed, lost the bestsurgical intervention time. And hight recurrence rate of postoperative. Manypatients, the poor efficacy of transcatheter arterial chemoembolization, are notsensitive to radiotherapy. The complex characteristics of cancer may alsorequire some alternative manage-ment to improve the therapeutic efficacy ofconventional treatment. Numerous effective anticancer drugs have beendeveloped from batanical sources. After herbal medicine long-term treatmentcan prevent cancer recurrence and meta-stasis, can reduce the side effects ofradiotherapy and chemotherapy, it can also enhance the effect of radiotherapyand chemotherapy. To prolong the survival time for patients with advancedcancer or not surgery or radiotherapy and chemotherapy can separate theapplication of traditional herbal medicine.There are two different means of communication between cells. One isdoes not require direct contact with the cells, growth factor or hormone media-ted, another is a cell contact-mediated communication. The latter is Gapjunctition intercellular communication which has a broad physiogical functionincluding regulation of cell growth,cell differentiation,and maintenance oftissue homeostasis. Several second messengers and small molecules aretransported through gap junctions, including cAMP,cGMP,inositol1,4,5-trisphosphate(IP3),and Ca++ions. Gap junctions are intercellular channels formed by the interactionof two hemichannels-connexons, one of which iscomposed of six protein subunits,Connexins(Cx)are subunits of gapjunctional channels. The mechanisms of carcinogenensis may be related withthe block of GJIC of homologous and heterologous communication betweentumor cells and surrounding normal cells. In humans, at least15membershave been described and their expression is tissue-specific. In the liver, GJICinvolves at least three different connexins, Cx32,Cx26and Cx43,dependingon the cell type or cell position in the lobule. In vivo and vitro, normalhepatocytes mainly express Cx26,whereas hepatoma cell lines expressessentially Cx43.Many studies have reported that Cx genes as a candidate tumorSuppressor gene-mediated GJIC to inhibit tumorigenesis. Abnormal connexingene expression in tumor cells, not with the loss of the genomic DNA ormutations, but the expression level of the cuts, It is well known that the loss ofCx in cancer. Clearly suggest that restoring the expression of Cx to inhibittumor growth is a viable treatment strategy.Baicalin, one of the main active compounds of scutellaria baicalensispossesses anti-inflammatory,anti-allergy,antioxidant and antitumor properties.Recent studies have shown that certain concentration of baicalin can inhibitproliferation of prostate cancer,lung cancer,Malignant lymphoma,myeloma,hepatocarcinoma et al. We focused our attention on Baicalin because of theirsupposed roles in tumor therapy as well as in the improvement of Cx,Currently there is no report. In this study. we treat HCC cell line ofSMMC-7721cell with Chinese herbal baicalin, to investigate the expressionof Cx26and Cx43gene transcription and protein levels. Traditional Chinesemedicine for the anti-cancer mechanism of research and clinical applicationprovides new theory and experiment basis methods.Methods:1The cells were divided into four groups:(1)blank control group,(2) baicalingroup(10mg/l),(3) baicalin group(20mg/l),(4) baicalin group(40mg/l) 2The mRNA expressional levels of Cx26,Cx43in SMMC-7721cells weremeasured by RT-PCR.3The protein expression levels of Cx26in SMMC-7721cells were measur-ed by Western blotting.4The protein expression levels of Cx43in SMMC-7721cells were measur-ed by immunocytochemcal staining.Result:1After treated with baicalin48h, the expressional levels of Cx26Cx43mRNAin SMMC-7721cells.After treated with different concentrations of baicalin48h,Cx26mRNA inSMMC-7721cells were significantly upper than that in control group,all ofthem had significant changes (P<0.05).Compared among different concentra-ations of baicalin, all of them had significant changes(P<0.05).After treated with baicalin48h, the expressional levels of Cx43mRNA inSMMC-7721cells had no significant difference compared with control group(P>0.05). Compared among different concentrations of baicalin,all of themhad no significant changes(P>0.05).2After treated with baicalin48h, the expressional levels of Cx26in SMMC-7721cells were significantly upper than those in control group, all of themhad significant changes (P<0.05). Compared among different concentrationsof baicalin, all of them had significant changes(P<0.05).3After treated with baicalin48h, the expressional levels of Cx43in SMMC--7721cells with immunocytochemisty. Cx43was dispersively expressed inthe cytoplasm of SMMC-7721cells, While with the raising of concentrationsof baicalin,Cx43were significantly upper than that in control group,all ofthem had significant changes (P<0.05).Compared among differentconcentrations of baicalin, all of them had significant changes(P<0.05).Conclusion:1Baicalin could significantly up-regulate the mRNA expressional levels ofCx26in SMMC-7721cells and the affect the expression of Cx26protein.With the raising of concentrations of baicalin, the expression of Cx26in experimental groups gradually increased.2The expression of Cx43mRNA in SMMC-7721cells have no significantchanges but the expression of protein were significantly raised as the baicalinconcentration elevated in48h.3Upregulation of Cx26and Cx43can lead to the restoration or enhancementof cell GJIC, there by inhibiting the growth of cancer cells, it is likely to beone of the important molecular mechanism of baicalin to inhibit tumor growth.Which will as a new meaning to treat hepatocellular carcinoma. But baicalinhow to regulate the Cx26and Cx43mechanism requires further study. |
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