Rationalized Computer-Aided Design of Matrix-Metalloprotease-Selective Prodrugs

Destruction of tumor vasculature by vascular disrupting agents in overcoming the limitation of EPR effect

Nanomedicine greatly improves the efficiency in the delivery of antitumor drugs into the tumor, but insufficient tumoral penetration impairs the therapeutic efficacy of most nanomedicines. Vascular disrupting agent (VDA) nanomedicines are distributed around the tumor vessels due to the low tissue penetration in solid tumors, and the released drugs can selectively destroy immature tumor vessels and block the supply of oxygen and nutrients, leading to the internal necrosis of the tumors. VDAs can also improve the vascular permeability of the tumor, further increasing the extravasation of VDA nanomedicines in the tumor site, markedly reducing the dependence of nanomedicines on the enhanced permeability and retention effect (EPR effect). This review highlights the progress of VDA nanomedicines in recent years and their application in cancer therapy. First, the mechanisms of different VDAs are introduced. Subsequently, different strategies of delivering VDAs are described. Finally, multiple combination strategies with VDA nanomedicines in cancer therapy are described in detail.

A promiscuous ancestral enzyme´s structure unveils protein variable regions of the highly diverse metallo-β-lactamase family

The metallo-β-lactamase fold is an ancient protein structure present in numerous enzyme families responsible for diverse biological processes. The crystal structure of the hyperthermostable crenarchaeal enzyme Igni18 from Ignicoccus hospitalis was solved at 2.3 Å and could resemble a possible first archetype of a multifunctional metallo-β-lactamase. Ancestral enzymes at the evolutionary origin are believed to be promiscuous all-rounders. Consistently, Igni18´s activity can be cofactor-dependently directed from β-lactamase to lactonase, lipase, phosphodiesterase, phosphotriesterase or phospholipase. Its core-domain is highly conserved within metallo-β-lactamases from Bacteria, Archaea and Eukarya and gives insights into evolution and function of enzymes from this superfamily. Structural alignments with diverse metallo-β-lactamase-fold-containing enzymes allowed the identification of Protein Variable Regions accounting for modulation of activity, specificity and oligomerization patterns. Docking of different substrates within the active sites revealed the basis for the crucial cofactor dependency of this enzyme superfamily.

Abnormal increase of miR-4262 promotes cell proliferation and migration by targeting large tumor suppressor 1 in gliomas

BACKGROUND

miRNA was recently detected as tumor suppressor or inducer in various cancers including gliomas. Due to the abnormal expression of miR-4262 in glioma cancer, we supposed that miR-4262 made efforts in proliferation and migration in glioma cancer.

METHODS

CCK-8, Transwell migration Assay and Wound-healing assay were appraisal assays for cell proliferation and migration. qRT-PCR and western blot were performed to test the expression of miR-4262, MMP2, MMP13 and LATS1 in glioma cancers tissues and cancer cells. The targeting detection between miR-4262 and LATS1 was detected by luciferase reporter assay.

RESULTS

miR-4262 expression was dramatically higher in glioma tumor tissues than in para-tumor control. Inhibition of miR-4262 in glioma cancer cells prominently inhibited cell proliferation and migration. Mechanically, downregulation of miR-4262 inhibited expression of matrix metalloproteinase (MMP) -2, -13. In addition, miR-4262 directly and negatively modulated expression of large tumor suppressor 1 (LATS1). Moreover, we discovered that overexpression of LATS1 could reverse the effects of miR-4262 on cell proliferation and migration, as well as the production of MMP-2, -13.

CONCLUSIONS

In glioma cancer, miR-4262 regulated cell proliferation and migration mediated by LATS1. This indicated that miR-4262 is a tumor inducer in glioma cancer and may be a feasible target for glioma therapy.

The Rebirth of Matrix Metalloproteinase Inhibitors: Moving Beyond the Dogma

The pursuit of matrix metalloproteinase (MMP) inhibitors began in earnest over three decades ago. Initial clinical trials were disappointing, resulting in a negative view of MMPs as therapeutic targets. As a better understanding of MMP biology and inhibitor pharmacokinetic properties emerged, it became clear that initial MMP inhibitor clinical trials were held prematurely. Further complicating matters were problematic conclusions drawn from animal model studies. The most recent generation of MMP inhibitors have desirable selectivities and improved pharmacokinetics, resulting in improved toxicity profiles. Application of selective MMP inhibitors led to the conclusion that MMP-2, MMP-9, MMP-13, and MT1-MMP are not involved in musculoskeletal syndrome, a common side effect observed with broad spectrum MMP inhibitors. Specific activities within a single MMP can now be inhibited. Better definition of the roles of MMPs in immunological responses and inflammation will help inform clinic trials, and multiple studies indicate that modulating MMP activity can improve immunotherapy. There is a U.S. Food and Drug Administration (FDA)-approved MMP inhibitor for periodontal disease, and several MMP inhibitors are in clinic trials, targeting a variety of maladies including gastric cancer, diabetic foot ulcers, and multiple sclerosis. It is clearly time to move on from the dogma of viewing MMP inhibition as intractable.

Enzymatically promoted release of organic molecules linked to magnetic nanoparticles

Magnetite-based magnetic nanoparticles have been successfully coupled to an organic system constituted of a fluorescent molecule, a tripeptide specifier and a spacer. The system is able to selectively release the fluorescent molecule upon targeted enzymatic hydrolysis promoted by a lysine/arginine specific protease.