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This study was purpose to investigate the effects of CD147 on the invasiveness of leukemia cells U937. The experiments were divided into 4 groups: control group, LPS group, CD147mAb group and LPS+CD147 mAb group. Cells were treated by lipopolysaccharide (LPS) or anti-CD147 monoclonal antibody, and the expression of CD147 and MMP-2, -9, the invasive potential of the cells in vitro and ex vivo, as well as the invasion of the implanted tumors in SCID mice were analysed by RT-PCR, FCM, gel zymography and invasion test in vitro respectively. The results showed that the expression of CD147 was elevated by the induction of LPS, and the enhanced expression of CD147 on U937 cells increased the production and secretion of MMP-2 and MMP-9 as measured by reverse transcription-PCR and gel zymography. An increased number of LPS-induced cells invading through a reconstituted basement membrane were observed by invasion assays. These responses were down-regulated after blocking CD147 with anti-CD147 antibody. At 30 days after intravenous injection of LPS pretreated U937 cells to SCID mice human U937 cells were found in the bone marrow and lung of the mice, indicating the invasion of the tumor cells. And overexpressions of CD147, MMP-2 and MMP-9 were found in the lung tissue of the mice injected with LPS-treated but not anti-CD147 antibody treated tumor cells. It is concluded that overexpression of CD147 on U937 cells may increase the secretion and activation of MMP-2 and MMP-9 and thus promote the invasiveness of the tumor cells.

Objective: To investigate a possible role of CD147 in the production of matrix metalloproteinase-9 (MMP-9) by fibroblasts and the invasion of melanoma cells., Methods: We cocultured CD147-expression melanoma cells with fibroblasts and examined the MMP-9 expression of fibroblasts by zymography and the invasion of melanoma cells by transwell invasion assay., Results: MMP-9 expression was enhanced in conditioned media, while cocultured with melanoma cells in a dose-dependent manner, and CD147 antibody inhibited the production of MMP-9 in the fibroblasts. When fibroblasts were cultured at the bottom of the lower compartment of transwell invasion model, the number of melanoma cells that invaded significantly increased. Addition of anti-CD147 antibody to the upper compartment transwell invasion model resulted in the significant inhibition of the melanoma cell invasion in reconstituted basement membrane., Conclusion: CD147 expressed in melanoma cells plays an important role in the melanoma cell invasion by stimulating the production of MMP-9 by fibroblasts.

Aim: To compare characteristics of polyclonal anti-sera against extracellular domain of hepatoma-associated antigen HAb18G/CD147(HAb18GEF) generated by different immunization schemes., Methods: BALB/c mice were immunized with GST-HAb18GEF fusion protein expressed in E.coli (routine immunization method), recombinant eukaryotic expression plasmid pcDNA3/HAb18G (intramuscular injection) and pcDNA3/HAb18G plasmid followed by human hepatoma cells booster (DNA-cell booster), respectively. The titers and Ig subclasses of polyclonal anti-sera against denatured and natural HAb18GEF were detected by indirect ELISA and cell ELISA, respectively. The specific binding of polyclonal anti-sera prepared by different immunization schemes to denatured HAb18GEF was analyzed by Western blot. The specific binding of polyclonal anti-sera produced by DNA-cell booster immunization to natural HAb18G antigen on hepatoma cells was detected by immunofluorescence staining., Results: GST-HAb18GEF immunization could induce polycolonal antibody IgG1 with higher titer mainly against denatured or linear epitopes on HAb18GEF. Antibody induced by pcDNA3/HAb18G intramuscular immunization was IgG2a with lower titer against natural epitopes on HAb18GEF. DNA-cell booster immunization could induce generation of polycolonal antibody IgG2a and IgG1 of moderate titers against the native epitopes on HAb18G., Conclusion: The polycolonal sera with different titers against different epitopes on HAb18GEF can be induced by different immunization schemes.