Synergistic effects of dendrosomal nanocurcumin and oxaliplatin on oncogenic properties of ovarian cancer cell lines by down-expression of MMPs

BACKGROUND: Contrary to the advantageous anticancer activities of curcumin (Cur), limited bioavailability and solubility hindered its efficacy. Here, nontoxic dendrosomal nano carrier with Cur was used to overcome these problems. Despite considerable antitumor properties of Oxaliplatin (Oxa), the limiting factors are drug resistance and adverse side-effects. The hypothesis of this study was to evaluate the possible synergism between dendrosomal nanocurcumin (DNC) and Oxa and these agents showed growth regulatory effects on SKOV3 and OVCAR3 cells. METHODS: and materials In the present study, colony formation, wound healing motility, cell adhesion, transwell invasion and migration assay and cell cycle arrest with or without DNC, Oxa and Combination were defined. In addition to, real time PCR and Western blot were used to analyze AKT, PI3K, PKC, JNK, P38 and MMPs mRNAs and proteins expressions. Docking of MMP-2-Cur, MMP-2-DNC and MMP-2-Oxa was performed and the results of all three complexes were simulated by molecular dynamics. RESULTS: Our findings illustrated that DNC had the greatest effect on cell death as compared to the Cur alone. Moreover, the growth inhibitory effects (such as cell death correlated to apoptosis) were more intense if Oxa was added followed by DNC at 4 h interval. However, insignificant effects were observed upon simultaneous addition of these two agents in both cell lines. Besides, a combination of agents synergistically alters the relative expression of MMP-9. CONCLUSIONS: The docking results showed that His70 and Asp100 may play a key role at the MMP-2 binding site. The matrigel invasion as well as cell viability of ovarian cancer cell lines SKOV3 and OVCAR3 by DNC alone or in combination with Oxa was inhibited significantly. The inhibitory effects of these agents were due to the differential expression levels of MMP 2 and MMP 9 regulated by multiple downstream signaling cascades. From the molecular dynamic simulation studies, it was confirmed that DNC established a strong interaction with MMP-2.

Alternagin-C binding to α2ß1 integrin controls matrix metalloprotease-9 and matrix metalloprotease-2 in breast tumor cells and endothelial cells

Background: Matrix metalloproteinases (MMPs) are key players in tumor progression, helping tumor cells to modify their microenvironment, which allows cell migration to secondary sites. The role of integrins, adhesion receptors that connect cells to the extracellular matrix, in MMP expression and activity has been previously suggested. However, the mechanisms by which integrins control MMP expression are not completely understood. Particularly, the role of α2ß1 integrin, one of the major collagen I receptors, in MMP activity and expression has not been studied. Alternagin-C (ALT-C), a glutamate-cysteine-aspartate-disintegrin from Bothrops alternatus venom, has high affinity for an α2ß1 integrin. Herein, we used ALT-C as a α2ß1 integrin ligand to study the effect of ALT-C on MMP-9 and MMP-2 expression as well as on tumor cells, fibroblats and endothelial cell migration. Methods: ALT-C was purified by two steps of gel filtration followed by anion exchange chromatography. The α2ß1, integrin binding properties of ALT-C, its dissociation constant (Kd) relative to this integrin and to collagen I (Col I) were determined by surface plasmon resonance. The effects of ALT-C (10, 40, 100 and 1000 nM) in migration assays were studied using three human cell lines: human fibroblasts, breast tumor cell line MDA-MB-231, and microvascular endothelial cells HMEC-1, considering cells found in the tumor microenvironment. ALT-C effects on MMP-9 and MMP-2 expression and activity were analyzed by quantitative PCR and gelatin zymography, respectively. Focal adhesion kinase activation was determined by western blotting. Results: Our data demonstrate that ALT-C, after binding to α2ß1 integrin, acts by two distinct mechanisms against tumor progression, depending on the cell type: in tumor cells, ALT-C decreases MMP-9 and MMP-2 contents and activity, but increases focal adhesion kinase phosphorylation and transmigration; and in endothelial cells, ALT-C inhibits MMP-2, which is necessary for tumor angiogenesis. ALT-C also upregulates c-Myc mRNA level, which is related to tumor suppression. Conclusion: These results demonstrate that α2ß1 integrin controls MMP expression and reveal this integrin as a target for the development of antiangiogenic and antimetastatic therapies.(AU)