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. Author manuscript; available in PMC: 2012 Oct 1.
Published in final edited form as: Cancer Epidemiol Biomarkers Prev. 2011 Aug 22;20(10):2237–2249. doi: 10.1158/1055-9965.EPI-11-0548

Figure 4. Relationships between H. pylori site of isolation, MLST type, and level of CagA expression.

Figure 4

Levels of CagA expression in individual strains were analyzed by immunoblotting, and CagA expression in each strain is expressed as signal intensity relative to a standard (CagA in strain 5001). The cagA promoter region of H. pylori Colombian strains was sequenced and the presence of an AATAAGATA motif located 40 nucleotides upstream of the ATG initiation site was scored for each strain. The H. pylori strains used in the study were isolated from patients living in regions of Colombia with either a low or high risk for gastric cancer, and were previously analyzed by MLST (32). Panels A and B depict the level of CagA expression and presence or absence of the AATAAGATA motif in strains from the two regions of Colombia (high risk or low risk for gastric cancer), while panels C and D depict the level of CagA expression and presence or absence of the AATAAGATA motif in strains of either European or African ancestral origins, based on MLST analysis. p-values (panels A and C) were determined by using Student’s t-test.