The Role Of Cx43, Smad4and PCNA In The Occurrence And Development Of Gastric Carcinoma And The Relationship Among Them

Gastric carcinoma is one of the common digestive malignant tumor, andis located the first place in the incidence and death rate of all kinds of tumorsin China.Normally,the multiplication and apoptosis of the gastric epitheliamucosae cell keeps a dynamic balance.while the balance maintenance dependson the together modulating control of oncogene,anti-oncogene and some othercell factors.During the course of the arising and progressive development ofgastric cancer which is a multi factors,multi stages,multi steps process,theactivation of oncogene and inactivation of tumor suppressor gene aregenerally considered to be the basis of tumor formation and delelopment.Cx43plays a key role of intercellular signal transduction,As well Smad4which is key component of intracellular TGFβ/smads signaling pathways maybe subject to intercellular signal conduction influence,thus affecting PCNA.Indevelopment of gastric cancer among them there may be correlations on whichthe research has not been illustrated completely. By comparing the expressionof Cx43, Smad4and PCNA in gastric cancer and normal gastric mucosatissues and their relationship with the clinical pothologycharacteristics(differentiation, metastasis of lymph nodes,depth ofinvasion,TNM by stages) of gastric carcinoma,they might provide theoreticalbasis to the study of the pathogenesis of gastric carcinoma and new approathof clinical treatment.Part Ⅰ The relationship between Cx43,smad4, PCNA and gastriccarcinomaObjectiveTo detect the expression of Cx43,smad4and PCNA in normal and carcinomatous gastric tissue by immunohistochemisty, western blotting andRT-PCR, and reveal the relationship between them and gastric carcinomaoccurrence and development.MethodsTo collect60cases of gastric carcinoma and25cases of normal gastrictissue(tissue away the tumor more than10centimetres regarding as normaltissue for comparsion) which were surgically removed and certified bypathology,and were not adopted by radiotherapy and chemotherapy inChengde Medical College affiliated hospital from August,2011to, October,2012. Immunohistochemisty and western blotting were adopted to detect theexpression of Cx43,smad4and PCNA in normal and carcinomatous gastrictissue; the expression of Cx43mRNA,smad4mRNA and PCNA mRNA wasdetected by RT-PCR in normal and carcinomatous gastric tissue.To analyse theexperimental data we combined clinical pothology with statistics.Results1. Immunohistochemisty results1.1The expression of Cx43, Smad4and PCNA in different tissue1.1.1The expression of Cx43，and smad4in carcinomatous gastric tissuewere lower than they were in normal gastric tissue (P<0.05). The expressionof PCNA in carcinomatous gastric tissue was higher than that in normalgastric tissue (P<0.05)1.2The expression of Cx43, Smad4and PCNA in different age andgenders1.2.1The expression of Cx43, Smad4and PCNA in group of male andfemale and group of＞59and≤59years is not significant.1.3The expression of Cx43, Smad4and PCNA in differentclinicopathologic features of carcinomatous gastric tissue1.3.1The expression of Cx43and smad4in gastric carcinoma which werewell differentiated and moderately differentiated were higher than they were inpoorly differentiated gastric carcinoma (P<0.05).The expression of PCNA ingastric carcinoma which were well differentiated and moderately differentiated was lower than that in poorly differentiated gastric carcinoma(P<0.05).1.3.2The expression of Cx43and smad4in gastric carcinoma withoutlymph node metastasis were higher than they were in gastric carcinoma withlymph node metastasis (P<0.05). The expression of PCNA in gastriccarcinoma without lymph node metastasis was lower than that in gastriccarcinoma with lymph node metastasis (P<0.05).1.3.3The expression of Cx43and smad4in gastric carcinoma with TNMI+II were higher than they were in gastric carcinoma with TNM III+IV(P<0.05). The expression of PCNA in gastric carcinoma with TNM I+II waslower than that in gastric carcinoma with TNM III+IV (P<0.05).1.3.4The expression of Cx43and smad4in invasion of gastric carcinomanot getting in touch with serosa were higher than they were in gastriccarcinoma with getting in touch with serosa (P<0.05). The expression ofPCNA in invasion of gastric carcinoma not getting in touch with serosa waslower than that in gastric carcinoma with getting in touch with serosa(P<0.05).2. western blotting detection2.1The expression of Cx43, Smad4and PCNA protein in different tissue2.1.1The expression of Cx43，and smad4in carcinomatous gastric tissuewere lower than they were in normal gastric tissue (P<0.05). The expressionof PCNA in carcinomatous gastric tissue was higher than that in normalgastric tissue (P<0.05)2.2The expression of Cx43, Smad4and PCNA protein in different ageand genders2.2.1The expression of Cx43, Smad4and PCNA in group of male andfemale and group of＞59and≤59years is not significant.2.3The expression of Cx43, Smad4and PCNA protein in differentclinicopathologic features of carcinomatous gastric tissue2.3.1The expression of Cx43and smad4in gastric carcinoma whichwere well differentiated and moderately differentiated were higher than they were in poorly differentiated gastric carcinoma (P<0.05).The expression ofPCNA in gastric carcinoma which were well differentiated and moderatelydifferentiated was lower than that in poorly differentiated gastric carcinoma(P<0.05).2.3.2The expression of Cx43and smad4in gastric carcinoma withoutlymph node metastasis were higher than they were in gastric carcinoma withlymph node metastasis (P<0.05). The expression of PCNA in gastriccarcinoma without lymph node metastasis was lower than that in gastriccarcinoma with lymph node metastasis (P<0.05).2.3.3The expression of Cx43and smad4in gastric carcinoma with TNMI+II were higher than they were in gastric carcinoma with TNM III+IV(P<0.05). The expression of PCNA in gastric carcinoma with TNM I+II waslower than that in gastric carcinoma with TNM III+IV (P<0.05).2.3.4The expression of Cx43and smad4in invasion of gastric carcinomanot getting in touch with serosa were higher than they were in gastriccarcinoma with getting in touch with serosa (P<0.05). The expression ofPCNA in invasion of gastric carcinoma not getting in touch with serosa waslower than that in gastric carcinoma with getting in touch with serosa(P<0.05).3. RT-PCR detection3.1The expression of Cx43, Smad4and PCNA mRNA in different tissue3.1.1The expression of Cx43，and smad4mRNA in carcinomatousgastric tissue were lower than they were in normal gastric tissue (P<0.05). Theexpression of PCNA mRNA in carcinomatous gastric tissue was higher thanthat in normal gastric tissue (P<0.05)3.2The expression of Cx43, Smad4and PCNA mRNA in different ageand genders3.2.1The expression of Cx43, Smad4and PCNA mRNA in group ofmale and female and group of＞59and≤59years is not significant.3.3The expression of Cx43, Smad4and PCNA mRNA in differentclinicopathologic features of carcinomatous gastric tissue 3.3.1The expression of Cx43and smad4mRNA in gastric carcinomawhich were well differentiated and moderately differentiated were higher thanthey were in poorly differentiated gastric carcinoma (P<0.05).The expressionof PCNA mRNA in gastric carcinoma which were well differentiated andmoderately differentiated was lower than that in poorly differentiated gastriccarcinoma (P<0.05).3.3.2The expression of Cx43and smad4mRNA in gastric carcinomawithout lymph node metastasis were higher than they were in gastriccarcinoma with lymph node metastasis (P<0.05). The expression of PCNAmRNA in gastric carcinoma without lymph node metastasis was lower thanthat in gastric carcinoma with lymph node metastasis (P<0.05).3.3.3The expression of Cx43and smad4mRNA in gastric carcinomawith TNM I+II were higher than they were in gastric carcinoma with TNMIII+IV (P<0.05). The expression of PCNA mRNA in gastric carcinoma withTNM I+II was lower than that in gastric carcinoma with TNM III+IV(P<0.05).3.3.4The expression of Cx43and smad4mRNA in invasion of gastriccarcinoma not getting in touch with serosa were higher than they were ingastric carcinoma with getting in touch with serosa (P<0.05). The expressionof PCNA mRNA in invasion of gastric carcinoma not getting in touch withserosa was lower than that in gastric carcinoma with getting in touch withserosa (P<0.05).Conclusions1. Immunohistochemical positive signals of Cx43, smad4and PCNAwere significant differences between normal gastric tissue and gastriccarcinoma,also were concerned with differentiation degree, lymph nodemetastasis,TNM by stages and depth of invasion of gastric carcinoma,whilenot significant with age and gender.2. western blot technology protein expressions of Cx43, smad4andPCNA were significant differences between normal gastric tissue and gastriccarcinoma,also were concerned with differentiation degree, lymph node metastasis, TNM by stages and depth of invasion of gastric carcinoma,whilenot significant with age and gender.3. RT-PCR detection Cx43, smad4and PCNA mRNA were significantdifferences between normal gastric tissue and gastric carcinoma, also wereconcerned with differentiation degree, lymph node metastasis, TNM by stagesand depth of invasion of gastric carcinoma,while not significant with age andgender.Part Ⅱ The relationship among Cx43, smad4and PCNA in the gastriccarcinomaObjectiveTo research the relationship among Cx43, smad4and PCNA in carcinomathrough analyzing experimental data of themMethodsTo analyse experimental data of Cx43, smad4and PCNA by the statisticalanalysis software.Results1. Immunohistochemical The correlation coefficient Cx43of andSmad4protein is:r=0.53(P<0.01);the correlation coefficient of Smad4andPCNA protein is:r=-0.49(P<0.01);the correlation coefficient Cx43of PCNAprotein is:r=-0.55(P<0.01).2. Western blotting The correlation coefficient Cx43of and Smad4protein is:r=0.88(P<0.01);the correlation coefficient of Smad4and PCNAprotein is:r=-0.79(P<0.01);the correlation coefficient Cx43of PCNA proteinis:r=-0.75(P<0.01).3. The correlation coefficient of Cx43mRNA and Smad4mRNAis:r=0.83(P<0.01);the correlation coefficient of Smad4mRNA and PCNAmRNA is:r=-0.81(P<0.01);the correlation coefficient of Cx43mRNA andPCNA mRNA is:r=-0.76(P<0.01).ConclusionsThe correlation of protein expression of Cx43and smad4was positive; The correlation of expression of Cx43mRNA and smad4mRNA waspositive;The correlation of protein expression of Cx43and PCNA wasnegative; The correlation of expression of Cx43mRNA and PCNA mRNAwas negative; The correlation of protein expression of smad4and PCNAwas negative. The correlation of expression of smad4mRNA and PCNAmRNA was negative.