Expression And Significance Of Prrx1-b In EMT Process Of Gastric Cancer

Objective: To investigate expression of paired homologous Box b(Prrx1-b),E-cadherin(E-ca)and Vimentin(Vim)in gastric cancer tissues,normal gastric mucosa tissues adjacent to gastric cancer(more than 5 cm from the edge of the tumor,pathologically confirmed non-cancer cells,referred to as para-cancer tissues),metastatic lymph nodes and non-metastatic lymph nodes,and the relationship between Prrx1-b and epithelial-mesenchymal transition(EMT)related markers.To further explore the effect of Prrx1-b on the evolution mechanism and prognosis of gastric cancer,so as to explore the potential application value of Prrx1-b in clinical diagnosis and treatment of gastric cancer.Methods: Immunohistochemistry(IHC)was used to stain gastric cancer tissues,paracancerous tissues,metastatic lymph nodes and non-metastatic lymph nodes.The relationship between Prrx1-b,E-ca and Vim and survival of gastric cancer patients was analyzed by Kaplan-Meier survival analysis.The number and intensity of brown-yellow granular staining cells in cytoplasm or nucleus determine the staining results.The specific counting method refers to Sood’s scoring method: 100 cells with positive cells in 10 high field of vision(x400)were counted in each sample,and the percentage of positive cells was calculated according to the average value.The number of stained cells: 0: positive cells < 5%,1: positive cells 5%-25%,2: positive cells 25%-50%,3: positive cells > 50%.Dyeing strength: 1 point: light yellow,2 points: dark yellow,3 points: brown.Total score was positive cell percentage + staining intensity score,total score < 2 was negative,and > 2 was positive.Results: The staining results showed that E-ca and Vim were mainly expressed in the cell membrane and/or cytoplasm,while Prrx1-b was mainly expressed in the nucleus.The expression levels of E-ca,Vim and Prrx1-b were not related to gender(P > 0.05),age(P > 0.05),tumor size(P > 0.05),carcinoembryonic antigen(CEA)expression(P > 0.05),carbohydrate antigen 199(CA-199)expression level(P > 0.05),but not to location(P < 0.05),differentiation degree(P < 0.05),and stage(P < 0.05).N stage(P < 0.05).The positive expression rates of E-ca in cancer tissues and adjacent tissues were 31.6% and 56.0%.The difference was significant(P < 0.001).The positive expression rates of E-ca in metastatic and non-metastatic lymph nodes were 48.1% and 68.1%.The difference was also significant(P = 0.008).The positive expression rates of Vim in cancer tissues and adjacent tissues were 63.7% and 53.0%,respectively.The difference was significant(P = 0.046).The positive expression rates of Vim in metastatic and non-metastatic lymph nodes were 62.0% and 46.1%,respectively.The difference was also significant(P = 0.038).The positive expression rates of Prrx1-b in cancer tissues and adjacent tissues were 54.2% and 37.5%.The difference was significant(P = 0.002).The expression rates of Prrx1-b in metastatic and non-metastatic lymph nodes were 65.9% and 48.1%.The difference was also significant(P = 0.019)(Table 5).According to the different expression levels of E-ca,Vim and Prrx1-b,we found that the expression levels of Prrx1-b and E-ca in gastric cancer tissues,paracancerous tissues,metastatic lymph nodes and non-metastatic lymph nodes were negatively correlated,while the expression levels of Vim in the corresponding tissues were positively correlated.The median survival time of E-ca positive expression group and negative expression group was 33 months and 26 months respectively,with significant difference(P = 0.0200).The median survival time of Vim positive expression group and negative expression group was 33 months and 38 months respectively,with significant difference(P = 0.0284).The median survival time of Prrx1-b positive expression group and negative expression group was 36 months and 40 months respectively,with significant difference(P = 0.0460).Conclusion: Prrx1-b is positive in gastric cancer and metastatic lymph nodes,negatively correlated with E-cadhein expression and positively correlated with Vim expression,suggesting that Prrx1-b regulates the invasion and metastasis of gastric cancer by promoting EMT.Prrx1-b is associated with poor prognosis of gastric cancer and may become a new target for treatment of gastric cancer.Future research should focus on this.