Investigation On The Role Of PIK3CA In Esophageal Squamous Cell Carcinoma

Objective: To explore the role of PIK3 CA in Kazakh’s esophageal squamous cell carcinoma(ESCC) and esophageal cancer cell lines EC9706 and Ecal09. Methods: Using immunohistochemistry to analyze the relationship between pathological parameters of Kazakh’s ESCC and PIK3 CA expression. EC9706 and Eca109 cells were transfected with specific siRNA using lipofectamine2000. The cells were divided into 3 groups: blank control group(normal growth), negative control group(transfected with scramble-siRNA) and experimental group(transfected with PIK3CA-siRNA). The protein expression of PIK3 CA was detected by Western blot. The cell proliferation, migration and invasion ability were examined by MTT assay, wound healing assay and transwell invasion assay respectively. The cell apoptosis and cell-cycle were analyzed by flow cytometry. Results: Expression of PIK3 CA was significantly higher in Kazakh’s ESCC than that in paired normal control(P<0.001); but no significant correlation was obserbed between PIK3 CA expression and the gender, age, depth of invasion, tumor differentiation degree and lymph node metastasis(P>0.05). Both of two cell lines, transfected with siRNA, the protein expression of PIK3 CA were significantly down-regulated(P<0.01, P<0.05); the proliferation(P<0.05, P<0.01), migration(P<0.05) and invasion(P<0.01) were significantly reduced after successful knock-down of PIK3 CA compared with normal control. The cell cycle was arrested at S phase and the apoptosis rate was significantly increased(P<0.01). Conclusion: PIK3 CA was significantly up-regulated in Kazakh’s ESCC compared with adjacent normal tissue and knock-down of PIK3 CA could inhibit the proliferation, migration and invasion of ESCC cells, the cell cycle was disordered and the apoptosis rate was increased.