Detection of HER2 expression and its structural alterations in gastric cancer tissues infected with cagA+ H. pylori

BackgroundHelicobacter pylori (HP) cagA is the causing agent for development of gastric cancer (GC). H. pylori also involves to trigger the EGFR (epidermal growth factor receptor) expression in gastric cancer cells. However, the prognostic relation of cagA with HER2 status in GC was not well understood. ObjectiveThe main aim of this study was to investigate the link of HER2 expression with CagA+ H. pylori in GC tissues. Materials and MethodsThe study was performed on 85 GC tissues of GC patients. The specific primers of 16S rDNA and cagA for PCR amplification were used. For investigation of HER2 status in GC tissues, immunohistochemistry and PCR amplification were performed. In silico study was performed for the investigation of interactive potential of HER2 with CagA protein. ResultsPCR amplified the 54 (63.52 %) of 85 GC tissues for HP that showed 34 (62.96 %) cagA+ HP. Immunohistochemistry of tissues revealed 57 (67.05 %) diffuse and 28 (32.94 %) intestinal type cancer. Of 85 cases, 21 GC tissues scored (2 + or 3 +) for positive HER2 expression and score (0 or 1 +) of 64 (75.29 %) showed negative. Of 21 HER2 + GC tissue, 15 biopsies had cagA+ HP and 2 were negative. PCR amplified single amplicon in 17 (20 %) CagA+ tissues and 3 (5.55 %) in CagA - HP. The molecular interactions of CagA was also showed its efficiency for HER2 expression. ConclusionThe study concluded that CagA+ HP may induce HER2 overexpression in GC tissues.