The Study On The Correleation Between Expressions Of Gap Junction Proteins Connexin 26 And Connexin43 And The Occurence, Invasion And Metastasis Of Esophageal Squamous Cell Carcinoma

Background and objective:Esophageal Squamous Cell Carcinoma (ESCC) is one of leading cancers in China. Cellular progression to malignancy is thought to involve multistep events,,and the infiltration metastasis of tumor cell is the main reason of the death of patients. Cell gap junctions are widespread intercellular membrane channel structures which are composed of hexagonal arrangements of oligomeric proteins called connexins (Cxs). gap junction intercellular communication (GJIC) is an universal signal transduction pathway in multi cellular organisms, not only enabling tte adjacent cells to share directly ions and small water-soluble molecules(smaller than1000Da), but also participating the communication of energy and information in cells.GJIC is considered to play an important role in the control of cell proliferation, differentiation, the maintenance of homeostasis and morphogenesis. Correspondingly, any change in of GJIC is closely related to aberrant cell growth diseases, including malignant tumors. Some scholars believe that the incidence of malignant tumors and malignant phenotype may be related to suppression of gap junction protein expressionand GJIC function. As the basic structure of GJIC, the genes of gap junction proteins-Cx-have been classified as tumor suppressors which are multi-unit and developping conservative family.Cx gene expression has a certain tissue specificity and another crossover phenomenon, however,one cell type may express several connexin gene species.Cx26 and Cx43 expression in the ESCC have been reported. In order to further explore the relation of the expression of Cx26 and Cx43 with the invasion and metastasis of esophageal squamous cell carcinoma, to find early valid indicator of invasion and metastasis of esophageal carcinoma and to explore useful methods to suppress the invasion and metastasis of esophageal carcinoma, this article detects the expression of Cx26 and Cx43 protein and mRNA in 42 cases of esophageal squamous cell carcinoma,17 cases of tumor-adjacent mucosa tissues and 42 cases of normal mucosa by immunchistochemistry and RT PCR way. These study can provide a theoretical basis for exploring the molecular mechanism of carcinogenesis, invasion and metastasis of esophageal squamous cell carcinoma and finding out effective methods to suppress the occurence, development of esophageal squamous cell carcinoma.Materials and methods:1.42 cases of esophageal squamous cell carcinoma were collected in the First Affiliated Hospital, Zhengzhou University and the Second Affiliated Hospital, Zhengzhou University. All cases has no the history of the chemotherapy,radiotherapy and immunotherapy.All cases were identified by pathologist, it is entirely esophageal squamous cell carcinoma.19cases areⅠrank,15 cases areⅡrank,8 cases areⅢ rank.14 example appeared the lymph node metastasis,28 cases are non-lymph node metastasis.15 cases are on the low layer invaded and 27 cases on the deep layer invaded. Each all in site of tumor and far-tumor normal mucoma cut a piece of tissue.2.The expression of Cx26 and Cx43 protein and mRNA were detected in 42 cases of esophageal squamous cell carcinoma and normal mucosa by RT-PCR way and immunohistochemistry.3.All the experimental data were analyzed by SPSS11.0 statistical analysis software package, the count information calculated the positive rate and enumeration data were expressed by the Mean±standard deviation.The comparision of positive rate uses the Chi-square, the mean of two samples uses t-test, the mean of more than two groups uses ANVOA. The relation of two variable were analyzed by correlation analysis. taking a= 0.05 as the standard of significant differenceResults:1. The expression levels of Cx26 mRNA in the tissues of esophageal squamous cell carcinoma, carcinoma side atypical hyperplasia tissue and normal esophage mucosa were 0.707±0.097,0.787±0.084 and 0.879±0.046, respectively, the difference was statistically significant (P<0.05). The positive counts of the expression of Cx26 mRNA of gradeⅠ,ⅡandⅢof the esophageal squamous cell carcinoma were 0.816±0.074,0.766±0.092,0.758±0.099, respectively, the difference was statistically significant (P<0.05).In the tissues of esophageal squamous cell carcinoma, the positive counts of the expression of Cx26 mRNA on the low and deep infiltrating groups were 0.847±0.112,0.785±0.090, difference between the two groups were significant (P<0.05); The positive count of the expression of Cx26 mRNA in lymph node metastasis Groups of cancer tissue (0.768±0.113) was lower than those without lymph node metastasis carcinoma (0.825±0.083),respectively,a significant difference between them (P<0.05). 2. The positive expression level of Cx43 mRNA in the normal esophage mucosa was 0.783±0.051, while in adjacent atypical hyperplasia and carcinoma tissues, respectively,0.715±0.037,0.692±0.084, the difference was statistically significant (P<0.05). The positive counts of the expression of Cx43 mRNA of gradeⅠ,ⅡandⅢof the esophageal squamous cell carcinoma were 0.731±0.084,0.707±0.085, 0.638±0.038,respectively, the difference was statistically significant(P<0.05).In the tissues of esophageal squamous cell carcinoma, the positive counts of the expression of Cx43 mRNA on the low and deep infiltration groups were 0.726±0.105, 0.681±0.059, difference between the two groups was significant (P<0.05). The positive counts of the expression of Cx43 mRNA in lymph node metastasis group (0.638±0.113) was lower than those without lymph node metastasis carcinoma (0.785±0.083), respectively,a significantd iference between them (P<0.05).3. The positive rates of expression of Cx26 protein in esophageal squamous cell carcinoma, carcinoma side atypical hyperplasia tissue and normal esophageal tissues were 40.5%(17/42),70.6%(12/17) and 95.2%(40/42) respectively, a significant diference between them (P<0.05); The positive counts of the expression of Cx26 protein of gradeⅠ,ⅡandⅢof the esophageal squamous cell carcinoma were 68.4%, 20.0% and 12.5%,respectively, the difference was statistically significant (P<0.05); With the increase of invasion depth and malignancy, the positive rates of expression of Cx26 protein decreased clearly,93.3%(14/15)on the low infiltration groups and 11.1%(3/27) on the deep infiltration groups (P<0.05); The positive rates of expression of Cx26 protein in the group with lymph node metastasis was 21.4% (6/28), and it was lower significantly than those without lymph node metastasis 78.6%(11/14), a significant diference between group them (P<0.05).4. The positive rates of expression of Cx43 protein in esophageal squamous cell carcinoma was 31.0%(13/42), and it was significantly lower than the adjacent atypical hyperplasia 64.7%(11/17) and normal mucosa,88.1%(37/42),respectively, a significant diference between them(P<0.05); The positive counts of the expression of Cx43 protein of gradeⅠ,ⅡandⅢof the esophageal squamous cell carcinoma were 47.4%,26.7% and 0, respectively, a significant diference among them (P<0.05).With the increase of invasion depth and malignancy,the positive rates of expression of Cx43 protein decreased clearly,73.3%(11/15) on the low infiltration groups and 7.4%(2/27) on the deep infiltration groups (P<0.05); The positive rates of expression of Cx43 protein in the group with lymph node metastasis was 7.1%(2/28). While it was 78.6%(11/14) in the group without lymph node metastasis, the difference was statistically significant (P<0.05).5. Expression rate of Cx26 and Cx43 protein showed a positive correlation in esophageal squamous cell careinoma. The Positive expression group of Cx43 protein and negative group in esophageal squamous cell carcinoma, the Positive expression rate of Cx43 was 70.6%(12/17) and 96.0%(24/25), respectively,a significant diffrence between them(P<0.05).Conclusion:l.The positive expression of Cx26,Cx43 protein and mRNA in esophageal squamous cell carcinoma were both lower than that of Cx26,Cx43 protein and mRNA in normal esophagus mucosa, and the positive expression of Cx26,Cx43 protein in tumor-adjacent atypical hyperplasia epithelium had a trend of decreasing gradually. It hints that loss or decreased expression of Cx26, Cx43 maybe play an important role in the tumorigenesis and development of esophageal squamous cell carcinoma.2.It indicated that Cx26, Cx43 gene might contribute to invasion and metastasis of esophageal squamous cell carcinoma and its loss or decreased expression had closely correlation with invasion depth and lymph node metastasis of esophageal squamous cellca rcinoma. 3.There was a correlation between the expression of Cx26,Cx43 protein and pathological grade of tumor. It implied that Cx26, Cx43 gene made great contribution to cellular diferentiation.4.There were all positive correlation between the expression of Cx26,Cx43 protein and the expression of Cx26,Cx43 mRNA. It implied that the expressions of Cx26, Cx43 mRNA and protein had consistency.