Two Novel Tri-Aryl Derivatives Attenuate the Invasion-Promoting Effects of Stromal Mesenchymal Stem Cells on Breast Cancer

Background:

The concept of Epithelial-Mesenchymal Transition (EMT) to promote carcinoma progression has been recognized as a venue for research on novel anticancer drugs. Triaryl template-based structures are one of the pivotal structural features found in a number of compounds with a wide variety of biological properties including anti-breast cancer. Among the various factors triggering EMT program, cyclooxygenase-2 (COX-2), NF-κB as well as the transforming growth factor-beta (TGF-β) have been widely investigated.

Objective:

Here, we aim to investigate the effect of two novel compounds A and B possessing triaryl structures, which interact with both COX-2 and TGF-β active sites and suppress NF-κB activation, on EMT in a co-culture system with breast cancer and stromal cells.

Methods:

MDA-MB-231 and bone-marrow mesenchymal stem (BM-MS) cells were co-cultured in a trans-well plate. Migration, matrigel-based invasion and colony formation in soft agar assays along with Real- time PCR and Western blot analysis were performed to examine the effect of compounds A and B on the invasive properties of MDA-MB-231 cells after 72 hours of co-culturing with BM-MSCs. In addition, TGF-beta interaction was investigated by Localized Surface Plasmon Resonance (LSPR).

Results:

BM-MSCs enhanced migration, invasion and anchorage-independent growth of the co-cultured MDAMB- 231 cells. A reduction in E-cadherin level concomitant with an increase in vimentin and N-cadherin levels following the co-culture implied EMT as the underlying process. Compounds A and B inhibited invasion and anchorage-independent growth of breast cancer cells co-cultured with BM-MSCs at 10µM. The observed inhibitory effects along with an increase in E-cadherin and a reduction in vimentin and ZEB2 levels suggest that the anti-invasive properties of compounds A and B might proceed through the blockade of stromal cell-induced EMT, mediated by their interaction with TGF-beta.

Conclusion:

These findings introduce compounds A and B as novel promising agents, which prevent EMT in invasive breast cancer cells.

Topographic Characterization of Cu-Ni NPs @ a-C:H Films by AFM and Multifractal Analysis

In the present work three-dimensional (3-D) surface topography of Cu-Ni nanoparticles in hydrogenated amorphous carbon (Cu-Ni NPs @ a-C:H) with constant thickness of Cu and three thicknesses of Ni prepared by RF-Plasma Enhanced Chemical Vapor Deposition (RF-PECVD) system were investigated. The thin films of Cu-Ni NPs @ a-C:H with constant thickness of Cu and three thicknesses of Ni deposited by radio frequency (RF)-sputtering and RF-PECVD systems, were characterized. To determine the mass thickness and atomic structure of the films, the Rutherford backscattering spectroscopy (RBS) spectra was applied. The absorption spectra were applied to study localized surface plasmon resonance (LSPR) peaks of Cu-Ni NPs (observed around 608 nm in visible spectra), which is widened and shifted to lower wavelengths as the thickness of Ni over layer increases, and their changes are also evaluated by the 3-D surface topography. These nanostructures were investigated over square areas of 1 μm × 1 μm using atomic force microscopy (AFM) and multifractal analysis. Topographic characterization of surface samples (in amplitude, spatial distribution, and pattern of surface characteristics) highlighted 3-D surfaces with multifractal features which can be quantitatively estimated by the multifractal measures. The 3-D surface topography Cu-Ni NPs @ a-C:H with constant thickness of Cu and three thicknesses of Ni prepared by RF-PECVD system can be characterized using the multifractal geometry in correlation with the surface statistical parameters.

Effects of trehalose and sorbitol on the activity and structure of Pseudomonas cepacia lipase: spectroscopic insight

The stability of enzymes with no reduction in their catalytic activity still remains a critical issue in industrial applications. Naturally occurring osmolytes are commonly used as protein stabilizers. In this study we have investigated the effects of sorbitol and trehalose on the structural stability and activity of Pseudomonas cepacia lipase (PCL), using UV-visible, circular dichroism (CD) and fluorescence spectroscopy. Surface plasmon resonance (SPR) technique was used to trace changes in the refractive index and dielectric constant of the environment. The results revealed that catalytic activity and intrinsic fluorescence intensity of PCL increased in the presence of both osmolytes. Far-UV CD spectra indicated that the protein has undergone some conformational changes upon interacting with these osmolytes. Increasing the concentration of sorbitol led to changes in the refractive index and consequently the dielectric constant of environment; whereas in the case of trehalose, such changes were not significant. Unfavorable interactions of trehalose with protein surface induced higher preferential exclusion from the enzyme-water interface than that of sorbitol. Results of this report could give further insights about the stabilization mechanism of osmolytes.