Aberrant methylation of the 3q25 tumor suppressor gene PTX3 in human esophageal squamous cell carcinoma

Figure 1 Promoter methylation contributes to pentraxin 3 downregulation in esophageal squamous cell carcinoma cell lines. A: Pentraxin 3 (PTX3) mRNA expression was detected by reverse transcription polymerase chain reaction; B: The methylation status of PTX3 promoter was determined by methylation-specific polymerase chain reaction. C: Representative high-resolution analyses of the methylation status of individual CpG sites in the PTX3 promoter by bisulphite genomic sequencing. Each row represents one bacterial clone with one circle symbolizing one CpG site. Methylated and unmethylated CpG sites were indicated by black and white circles, respectively. PTX3: Pentraxin 3; GAPDH: Glyceraldehyde-3-phosohate dehydrogenase; MSP: Methylation-specific polymerase chain reaction; USP:Unmethylation.

Figure 2 The mRNA expression of pentraxin 3 was restored after treatment with demethylation agent 5-aza-2'-deoxycytidine in esophageal squamous cell carcinoma cell lines. PTX3: Pentraxin 3; GAPDH: Glyceraldehyde-3-phosohate dehydrogenase.

Figure 3 Representative methylation-specific polymerase chain reaction results of esophageal squamous cell carcinoma primary tumors (T) and paired adjacent nontumor tissues (N). Numbers1-8: Sample number. M: Methylation; U: Unmethylation.

Figure 4 Pentraxin 3 expression assessed by immunohistochemistry staining in esophageal squamous cell carcinoma tumor tissues and adjacent nontumor tissues. A: Significant expression of PTX3 was detected in adjacent nontumor tissues (x 40); B: Negative or weak expression of pentraxin 3 was observed in esophageal squamous cell carcinoma (x 40).