The Molecular Mechanism Of 67LR Promoting The Invasion And Metastasis Of HCC

Background & Aims: Laminin is one of the most important proteins of the extracellular matrix. 67 kD laminin receptor (67LR) is a non-integrin receptor of laminin which has been implicated in laminin-induced tumor cell attachment and migration, as well as in tumor angiogenesis, growth, invasion, and metastasis. Previous study of our lab had shown that over-expression of 67LR can promote the invasion ability of HepG2 cells. The aim of this study was to explore the molecular mechanism of 67LR enhancement of invasion of HCC cells.Methods: Transient transfection and stable cell line were employed to over-express 67LR in HCC cells and small interfering RNA was used to knock-down the expression of 67LR, which was measured by Flow Cytometer and semi-quantitative reverse transcription polymerase chain reaction (RT-PCR). The effect of 67LR on the genes expression was evaluated by semi-quantitative RT-PCR. Quantitative real-time PCR and gelatin zymography were carried out to confirm the results of semi-quantitative RT-PCR.Results: The expression of MMP-2, MMP-9 in 67LR over-expression stable HepG2 cells LR4 was significantly higher than pcDNA-1 and LR6 cell by semi-quantitative RT-PCR and quantitative real-time PCR. The activity of MMP-2 and MMP-9 in LR4 cell supernatant was higher than the other two cell lines. The transient transfection of 67LR could enhance the transcriptions of MMP-2, MMP-9, TIMP-1, TIMP-4, uPA, Hpa, Cath-B and Cath-D, and inhibit the transcriptions of TIMP-2 and TIMP-3. On the other hand, knock-down of 67LR exhibits the opposite effect on the expression of these genes.Conclusion: 67LR may alter the expression level of MMP-2, MMP-9, TIMP-1, TIMP-4, Hpa, uPA, Cath-B, Cath-D, TIMP-2 and TIMP-3 to increase HCC cells invasion ability.