No abstract

No abstract

No abstract

Metastasis is one of the main causes of death for patients with malignant tumors. Aberrant expression of matrix metalloproteinase-9 (MMP-9) has been implicated in the invasion and metastasis of various cancer cells. Here, we found that caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE) could inhibit the migration and invasion of human gastric carcinoma cells in Transwell migration assays. To understand the underlying mechanism, we showed that CADPE significantly inhibited phorbol 12-myristate 13-acetate (PMA)-induced increases in MMP-9 expression and activity in a dose-dependent manner. The inhibitory effect of CADPE on MMP-9 expression correlated well with the suppression of MMP-9 promoter activity and the reduction of MMP-9 mRNA. Reporter gene assay and electrophoretic mobility shift assay showed that CADPE inhibited MMP-9 expression by suppressing the activation of the nuclear transcription factor activator protein-1 (AP-1) and c-Fos, but not NF-κB. Moreover, CADPE inhibited PMA-induced phosphorylation of protein kinases involved in AP-1 activation, such as focal adhesion kinase (FAK), mitogen-activated protein kinase/ extracellular signal-regulated kinase (ERK) kinase (MEK), and ERK1/2, whereas CADPE had little effect on the phosphorylation of p38 and c-jun NH 2 -terminal kinase. Taken together, our findings indicate that CADPE could be a unique antitumor agent that specifically inhibits MMP-9 activity by targeting the activation of FAK/ MEK/ERK protein kinases and AP-1 transcription factor.

Controlled synthesis of spinel ZnFe2O4 nanoparticle-decorated ZnO nanofiber heterostructures was carried out with regularly varied particle sizes and uniform distribution. The obtained heterostructures possessed enhanced intrinsic peroxidase-like activity, and the activities regularly changed as the sizes of ZnFe2O4 nanoparticles varied. The heterostructures were further applied in sensitive colorimetric biosensing of urine glucose.