Overexpression of Bactericidal/Permeability-Increasing Fold-Containing Family BPIFB1 in Gastric Cancer Cells Leads to Differential Expression of E-Cadherin and MUC5AC

The human Bactericidal/Permeability-Increasing Fold containing family B, member 1 (BPIFB1), or also known as LPLUNC1, C20orf114, is a member of the BPI/LBP/PLUNC protein family. BPIFB1 differential expression patterns have been reported in several cancers such as nasopharyngeal carcinoma (NPC). However, in gastric cancer (GC) the role of BPIFB1 is not known, but the expression of the gene has been reported in the stomach co-expressing E-cadherin ( CDH1 ) together with making mucin 5, tracheobronchial/gastric mucin type A and C ( MUC5AC ). To investigate the role of BPIFB1 in GC development and its interactions with CDH1 and MUC5AC , overexpression of the gene was induced in three different GC cell lines; AGS, HGC-27 and MKN-45. The present of BPIFB1 protein in a transfected GC cell line was detected through gel Lumio Green Detection. BPIFB1 , CDH1 and MUC5AC expression were then performed via RT-PCR and quantitative Real-time PCR (qPCR) followed by statistical analysis ( p ≤ 0.05). BPIFB1 expression was detected in all transfected cells with the highest in AGS with the p = 0.003 followed by MKN-45 with the p = 0.009 and HGC-27 with the p = 0.015. The expression of MUC5AC is upregulated in BPIFB1 transfected GC cells whereby the highest expression is observed in MKN-45 with the p = 0.05 followed by AGS with the p = 0.001 and HGC-27 with the p = 0.026. CDH1 expression is downregulated in all BPIFB1 transfected GC cells with the lowest expression found in HGC-27 with the p = 0.001 followed by AGS with the p = 0.003 and MKN-45 with the p = 0.004. Thus, induction of BPIFB1 overexpression in vitro in GC cells contributes to the decreased in CDH1 expression and increased in MUC5AC expression suggesting that BPIFB1 other than co-expressed in the gastric gland with the two genes also regulates gene expression. We found that the overexpression of BPIFB1 downregulated the expression of CDH1 and upregulated MUC5AC gene expression. This finding was supported by both RT-PCR and qPCR. Conclusion: Our findings suggest that BPIFB1 is differentially expressed in GC cell lines and regulate the expression of CDH1 and MUC5AC .