Correlation of matrix metalloproteinase－2, －9, tissue inhibitor－1 of matrix metalloproteinase and CD44 variant 6 in head and neck cancer metastasis

This study aimed to explore the molecular mechanism in tumor invasion and metastasis. The expression of matrix metalloproteinase 2, 9 (MMP 2, MMP 9), tissue inhibitor 1 of matrix metalloproteinase (TIMP 1), cell adhesion molecule 44 variant 6 (CD44v6), HER2/neu and p53 was investigated in 154 patients with head and neck squamous cell carcinoma (SCC) by ABC and ImmunoMax immunohistochemical method. Their clinical relevance and correlation were analysed. The expression of MMP 2, MMP 9, TIMP 1, CD44v6, HER2/neu and p53 was found in cancer cells in 87.01%, 85.71%, 68.18%, 98.05%, 55.19% and 50.65% cases respectively. Linear regression and correlation analysis revealed that there was close positive relationship ( P <0.05) between the expression of MMP 2 and MMP 9, TIMP 1 and CD44v6, HER2/neu and MMP 9, MMP 2 and p53. Up regulation of MMP 2 was accompanied by advanced T stage ( P <0.01) . There was also a trend of MMP 2 expression being related with tumor metastasis. Increased expression of HER2/neu was found in patients with tumor recurrence( P <0.05). The expression of TIMP 1 was higher in laryngeal cancer than that in pharyngeal cancer, and higher in keratinizing and non keratinizing SCC than that in basaloid SCC( P <0.05). These findings suggested that MMP 2 and MMP 9, HER2/neu and MMP 9, MMP 2 and p53 had a coordinate function in aggression of tumor; that MMP 2 had a more important function than MMP 9 in tumor invasion and metastasis; and that HER2/neu might serve as a biomarker for poor prognosis in HNSCC.

Effects of (-)-epigallocatechin-3-gallate on expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in fibroblasts irradiated with ultraviolet A

Background It is known that ultraviolet irradiation can affect cellular function through a number of signaling pathways ( ) epigallocatechin 3 gallate (EGCG) is the major effective component in green tea and can offer protection from ultraviolet induced damage In this study, we investigated the protective mechanism of EGCG on human dermal fibroblasts damaged by ultraviolet A (UVA) in vitro Methods Transcription factor Jun protein levels were measured by Western blot Matrix metalloproteinase 1 (MMP 1) and tissue inhibitor of metalloproteinase 1 (TIMP 1) mRNA were studied by reverse transcription polymerase chain reaction (RT PCR) analysis in conjunction with computer assisted image analysis MMP 1 and TIMP 1 proteins were quantified by enzyme linked immunosorbent assay (ELISA) Results EGCG decreased transcription activity of Jun protein after induction by UVA Both the mRNA and protein levels of MMP 1 were increased by UVA irradiation, while no significant changes were observed in TIMP 1 levels The ratio of MMP 1 to TIMP 1 showed statistically significant differences compared with the control EGCG decreased the ratio of MMP 1 to TIMP 1 by inhibiting UVA induced MMP 1 expression ( P <0 05) Conclusion EGCG can protect human fibroblasts against UVA damage by downregulating the transcription activity of Jun protein and the expression of MMP 1 The ratio of MMP 1 to TIMP 1, rather than the levels of MMP 1 or TIMP 1 alone, may play a significant role in human skin photodamage

Effect of shRNA Inhibiting HIF1α Gene on TIMP1 Expression in RPE Cells

Small hairpin RNA （shRNA） was used to silence the HIF1α gene in human retinal pigment epithelial cells （RPE） under hypoxia in order to observe the effect of gene silencing on the expression of matrix metalloproteinase tissue inhibitor 1 （TIMP1）. By using chemical hypoxic inducer CoCl2 to mimic RPE hypoxic environment, shRNA against the targeting region of HIF1α mRNA sequence was synthesized by a method of in vitro transcription, and the HIF1α was interfered in RPE cultured under hypoxia （induced by 150 μmol/L CoCl2 ）. RT-PCR was employed to detect the expression of HIF1α and TIMP1. The expression levels of HIF1α and TIMP1 were measured by using Western blotting. The results showed that after the RPE were transfected with specific shRNA against HIF1α mRNA, RT PCR revealed that under hypoxia, the efficacy of HIF1α gene silencing in RPE was 83.4 %. Western blotting revealed that the expression levels of HIF1α protein was dramatically dropped. In addition, RT-PCR results demonstrated that the expression of TIMP1 mRNA was decreased by 28.9 %, and the expression levels of TIMP1 protein were also significantly reduced by Western blotting. It was suggested that shRNA targeted against HIF1α mRNA could effectively silence the HIF1α gene, subsequently effectively inhibit the hypoxia-induced up-regulation of TIMP1.