Expression Of Galectin-4 In Non Small Cell Lung Cancer And Its Effect On The Biological Behavior Of Tumor Cells

Objective The expression of galectin-4(Gal-4)in tissues and cells of non small cell lung cancer(NSCLC)were investigated to explore the significance of its expression in NSCLC tissues and the effection on the proliferation,migration and apoptosis of NSCLC cells.Methods 1.100 NSCLC patients were selected,the experimental group consistes of 100 cancer tissues by surgical resection,control group comes from the corresponding adjacent normal lung tissue.The expression of Gal-4 in both groups was examined by the immunohistochemical staining method,to analyze the relationship between the expression and clinicopathological features such as gender,age,smoking,histological type,tumor size,lymph node metastasis and distant metastasis.2.Three common NSCLC cell lines(lung adenocarcinoma: A549,lung squamous cell carcinoma: H520,large cell lung cancer: H460)were selected as the experimental group,and normal bronchial epithelial cells(BEAS-2B)were used as the control group.The expression of Gal-4mRNA and protein in 4 cells was detected by Real-time PCR and Western blot.The cell line with the highest expression of Gal-4 at the protein level was selected and transfected with LGALS4-siRNA to down-regulate the expression of Gal-4 protein.Transfection of NC-siRNA as blank group,Transfection efficiency was observed by transfection of FAM-siRNA.Western blot was used to detect the down-regulation of Gal-4 expression by transfected siRNA.Then,CCK8 method,scratch test and flow cytometry were used to study the effect of down-regulating Gal-4 protein on the biological behavior of A549 cells,such as proliferation,migration and apoptosis.Results 1.The expression rate of Gal-4(48.00%)in cancer tissue is significantly higher than that in adjacent normal lung tissue(0.00%)(P<0.05).2.The expression rate of Gal-4 in lung adenocarcinoma(84.44%)is significantly higher than that in Lung squamous cell carcinoma(22.22%)and large cell lung cancer(0.00%).The expression rate of Gal-4 with lymph node metastasis(61.22%)is significantly higher than that without lymph node metastasis(35.29%)in NSCLC(P <0.05).3.The expression of Gal-4 is associated with the lymph node metastasis in lung adenocarcinoma(P <0.05),but not associated with the lymph node metastasis in lung squamous cell carcinoma(P> 0.05).The expression of Gal-4 is not related with the gender,age,smoking,tumor size and distant metastasis(P>0.05).4.Real-time PCR detected the expression of Gal-4mRNA in A549,H460,H520 and BEAS-2B cells are 0.9992 0.2642,0.1179 0.3145,0.2515 0.0105,0.0053 0.0014.Western blot detected the expression of Gal-4 protein in A549,H460,H520 and BEAS-2B cells are 0.2401 0.0583,0.0005 0.0004,0.1134 0.0147,0.0002 0.0001.The expression of Gal-4 gene and protein in 4 cell lines is consistent.The expression of Gal-4 in NSCLC cells is significantly higher than that in normal bronchial epithelial cells,and the expression level in lung adenocarcinoma is the highest,which is significantly higher than that in squamous cell lung cancer and large cell lung cancer(P all <0.05).5.The expression of Gal-4 in A549 is the highest,A549 cells is transfected into FAM-siRNA,The fluorescence transfection efficiency was about 100%,si RNA is successfully transfected.6.Western blot showed that Gal-4 protein is expressed in A549 cells transfected with three LGALS4-siRNA target sequences and NC-siRNA sequence: LGALS4-homo-1021,LGALS4-homo-864,LGALS4-homo-346,NC-siRNA: 0.2280 0.0895,0.1325 0.1271,0.0250 0.0198,0.2447 0.0734.There different LGALS4-siRNA sequences are down-regulation of Gal-4 expression in A549 cells,the effect of LGALS4-homo-346 sequence on interference of Gal-4 protein expression is the best(P<0.05).7.the LGALS4-homo-346 sequence was used to down-regulate the expression of Gal-4 protein for cell function experiments,CCK8 experiments showed that the proliferation of A549 cells at 48 h and 72 h after transfection with NC-siRNA and LGALS4-siRNA was: 48h:0.4993 0.0086,0.2707 0.0011,72h:0.5398 0.0165,0.3752 0.0005.The cell proliferation ability of the transfected group is significantly lower than that of the control group(P <0.05).The migration ability of A549 cells after transfection of NC-siRNA and LGALS4-siRNA was observed at 48 h after scratching,The scratch distance was 98.3333 3.2146,7.6667 0.5774 respectively,and the migration ability of cells in the transfection group is significantly lower than that of control group(P<0.05).Flow cytometry experiment showed that the apoptosis of A549 cells transfected with NC-siRNA and LGALS4-siRNA was:21.7108 34.6697,22.3683 35.4454,and there is no significant difference in apoptosis between the transfection group and the control group(P>0.05).Conclusion 1.The expression rate of Gal-4 protein in NSCLC tissue and the expression of Gal-4 gene and protein in NSCLC cells are increased,and the most obviously increased in lung adenocarcinoma.2.The expression of Gal-4 protein is the same in NSCLC tissues and cells,and the expression of Gal-4 gene and protein in NSCLC cells is consistent.3.Gal-4 has important clinical significance in predicting lymph node metastasis of lung adenocarcinoma.4.Gal-4 can promote the proliferation and migration of lung adenocarcinoma cells,but has no effect on its apoptosis.