Fig 2: Promoter DNA methylation analysis of the CD24, CD44, CD133, and CD147 genes in OSCC cell lines, primary OSCC tumor tissues, and normal oral mucosal tissues. (A) Schematic structure of the CpG islands at the promoter regions for CD24, CD44, CD133, and CD147. (A) The primer locations for MSP were indicated as an orange bar for each gene. (B) MSP results in OSCC cell lines. Gel pictures describe the methylation analysis by MSP. DNA methyltransferase 1 and 3b knockout HCT116 cells (DKO) were included as positive controls. The PCR products recognized the unmethylated (U) and methylated (M) genes. DKO cells were used for the unmethylated control. IVD = in vitro methylated control; ddH2O = water control containing no DNA. (C) Methylation frequency of the CD24, CD133, and CD147 genes between the samples from patients with OSCC (n = 102) and the normal oral mucosal tissue samples (n = 45).

Fig 3: Protein levels of MMP-9 and EMMPRIN in CRSwNP. (A) Western blots of MMP-9 and EMMPRIN in controls (C1-C12) and patients (P1-P37). (B) relative percentages in protein levels of MMP-9 and EMMPRIN in controls and patients; (C) comparison of relative expression of MMP-9 and EMMPRIN between smoking and non-smoking CRSwNP patients showed no significant difference between the two groups but a trend of the MMP-9 protein to increase on smokers; (D) asthma was not associated with a significant increase in MMP-9 and EMMPRIN expression in CRSwNP patients. CRSwNP: Chronic rhinosinusitis with nasal polyps.

Fig 4: Decrease in invasion activities of SaOS-2 cells transfected by EMMPRIN siRNA. Matrigel invasion assays after transfection of the EMMRIN siRNA into SaOS-2 cells for 24 h. Following incubation, the membranes were removed from the inserts and mounted on slides. a. The number of invading cells was counted under a light microscope. The Matrigel assay was performed in triplicates. * p < 0.05 compared with cells transfected with control siRNA. b. Representative images of Matrigel invasion assay. Scale bar, 100 μm

Fig 5: Reversal of MMP2 stimulation in co-cultures of SaOS-2 and osteoblast by EMMPRIN siRNA transfection. a SaOS-2 and osteoblast showed weak gelatinolytic band for pro-MMP2 when cultured alone (Lanes 1, 2). When osteoblast and SaOS-2 were co-cultured, enhanced stimulation of pro-MMP2 was observed (Lane 3). This stimulation was reversed by transfection of SaOS-2 with EMMPRIN-targeting siRNA (Lanes 4–6). Data shown are representative images of individual cell lines from three separate experiments. b Comparison of grayscale ratio of gelatinolytic band for pro-MMP2 *, p < 0.05 compared with control