Promoter hypomethylation up-regulates CD147 expression through increasing Sp1 binding and associates with poor prognosis in human hepatocellular carcinoma.
Bottom Line: Significantly higher expression of CD147 and significantly lower promoter methylation level were observed in HCC cell lines compared to normal cell lines and tissues control.Moreover, HCC patients with unmethylated CD147 promoter had a significantly higher recurrence rate (88.1%versus 58.3%; P < 0.05) and death rate (83.3%versus 50.0%; P < 0.05) than patients with methylated CD147 promoter.In conclusions, promoter hypomethylation up-regulates CD147 expression primarily through increasing Sp1 binding and associates with poor prognosis in HCC patients.
Affiliation: State Key Laboratory of Cancer Biology, Cell Engineering Research Centre & Department of Cell Biology, Fourth Military Medical University, Xi'an, China.Show MeSH
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Mentions: BGS was carried out to investigate the methylation level of CD147 promoter in 54 pairs of HCC and ANT tissues. The percentage of methylated CpG sites in all sequenced CpG sites was used to represent the methylation level for each sample as previously described . The representative data from 10 paired tissues were shown in Figure 6A. Our results showed that the methylation level of HCC tissues was significantly lower than that of ANT tissues (45.95 ± 11.41%versus12.5 ± 5.44%, P < 0.05). Similar results were also obtained from MSP analysis in which methylation of CD147 promoter was observed in 12 of 54 (22.22%) HCC tissues and 25 of 54 (46.3%) ANT tissues (P < 0.05). The representative MSP amplifications from 10 paired tissues were shown in Figure 6B. To analyse the correlation between CD147 expression and methylation status of CD147 promoter in HCC tissues, immunohistochemistry analysis was done to detect the CD147 protein expression. Our data showed that 42 of 54 (77.78%) HCC tissues exhibited positive staining. The representative positive and negative staining of CD147 was shown in Figure 6C. Correlation analysis indicated that there was a significant inverse correlation between the CD147 expression level (denoted as total score of immunohistochemistry) and promoter methylation with a correlation coefficient (r) =−0.615 and R2 linear = 0.378 (Fig. 6D).
Affiliation: State Key Laboratory of Cancer Biology, Cell Engineering Research Centre & Department of Cell Biology, Fourth Military Medical University, Xi'an, China.