Limitations of cross-talk between osteosarcoma and bone marrow-derived mesenchymal stem cells

Objectives: Metastasis is a multi-step process which leads the tumor cells to escape from primer tumor region due to their need to gain malign phenotypes. While the effect of bone marrow-derived mesenchymal stem cells upon metastasis is not certain, some studies point out bone marrow-derived mesenchymal stem cells (BM-MSCs) to have this ability due to cell-cell interaction, released cytokines, and organization with the extracellular matrix in the micro-environment. Cross-talk via soluble factors also shifts the metastatic character. Patients and Methods: In this study, the effects of mesenchymal stem cells on tumor behavior by creating different microenvironments in 3-dimensional (3D) in vitro cancer model is analyzed. The BM-MSCs and osteosarcoma cells were co-cultured via hanging-drop modeled 3D structure in normoxic and hypoxic conditions, and the cross-talk was modeled to measure their chemoattractant effects The invasion and migration rates were measured with xCELLigence DP real-time cell analysis system. Mann Whitney U Test was used to compare independent samples. All P-values <0.05 were considered statistically significant. Results: In this study, the most effective chemoattractant that increases the rate of migration in the osteosarcoma cell line under both normoxic (P 0.02) and hypoxic (P 0.004) conditions have been found to be the chemoattractant obtained from the BMSC culture. Conclusion: Soluble factors secreted by BM- MSCs to micro-environment are highly effective chemoattractants for osteosarcoma, nevertheless the stem cells that have been co-cultured with the MG-63 decrease this behavior. These results could provide a new scientific approach to downregulate the metastasis induced by the effect of BM-MSCs.Dokuz Eylul UniversityTailor of Science Biotechnology Innovation I.C

Repositioning of Metformin: Anticancer Agent for Hypoxic Neuroblastoma Cells

Objectives:Neuroblastoma is an extracranial solid tumor of early childhood that has a hypoxic environment. VEGF and HIFs molecules play a role in adaptation to this microenvironment. Hypoxic microenvironment leads to poor prognosis and inadequate treatment of neuroblastoma. Metformin has been shown to inhibit tumor growth, might be a potential chemotherapeutic agent. The anti-cancer activity of Metformin on SH-SY5Y cells are not fully elucidated. The aim of this study is to determine the anti-cancer effect of Metformin on SH-SY5Y cells and to elucidate its molecular action mechanism in hypoxia/normoxia

Interferometric Investigation of Cell Stiffness and Morphology on Oxidative Stress- Induced Human Umbilical Vein Endothelial Cells (HUVEC)

Cell stiffness that can be measured accordingly elasticity modulus is an important biomechanical feature that plays a one-to-one role on the basic features of the cell, such as migration and proliferation, and this feature is significantly affected by the characteristic of the cytoskeleton. Reactive Oxygen Species (ROS) are side-products formed as a result of the cell's general metabolic activities. Cells have a very effective antioxidant defense to deactivate the toxic effect of ROS however, oxidative stress at abnormal levels significantly damages cellular balance. Many conditions such as inflammation, neurodegenerative and cardiovascular diseases and aging are associated with oxidative stress. Besides, oxidative stress is one of the parameters that affect the biomechanical behavior of the cell, but the mechanism of this effect still remains a mystery. In this study, oxidative stress was mimicked on Human Umbilical Vein Endothelial (HUVEC) cells by using H2O2 and the effect of this situation on cell stiffness and morphological structure was investigated interferometrically for the first time. The changes that occurred in the cell stiffness were determined by calculating the elasticity modules of the cells. Cells were exposed to H2O2 for 24 hours at 0.5 mM and 1 mM concentrations, and as a result, cell stiffness was shown to decrease due to increased H2O2 concentration

Optimization of Different Surface Modifications for Binding of Tumor Cells in a Microfluidic Systems

Objectives:Microfluidic technology is a fast-growing area and provide high-efficient MEMS (Micro-Electro-Mechanical-Systems) sensor integration platform that helps to advance healthcare systems. Due to proper the chemical and mechanical properties of polymers, PDMS (Polydimethylsiloxane) (6) and PMMA (Poly-methyl-methacrylate), they became on the best candidate for health care studies in microfluidic studies (7). Besides, they perform great optical properties for observation of living cell experiments. To increase their performance, surface interactions works with cells, modification techniques are widely used in microfluidic chips. In this paper, our primary purpose is to modify such polymers and glass with matrigel, PDA and APTES so as to increase cell-surface interaction

Holographic Cell Stiffness Mapping Using Acoustic Stimulation

Accurate assessment of stiffness distribution is essential due to thecritical role of single cell mechanobiology in the regulation of many vitalcellular processes such as proliferation, adhesion, migration, and motility.Cell stiffness is one of the fundamental mechanical properties of the cell andis greatly affected by the intracellular tensional forces, cytoskeletalprestress, and cytoskeleton structure. Herein, we propose a novel holographicsingle-cell stiffness measurement technique that can obtain the stiffnessdistribution over a cell membrane at high resolution and in real-time. Theproposed imaging method coupled with acoustic signals allows us to assess thecell stiffness distribution with a low error margin and label-free manner. Wedemonstrate the proposed technique on HCT116 (Human Colorectal Carcinoma) cellsand CTC-mimicked HCT116 cells by induction with transforming growth factor-beta(TGF-\b{eta}). Validation studies of the proposed approach were carried out oncertified polystyrene microbeads with known stiffness levels. Its performancewas evaluated in comparison with the AFM results obtained for the relevantcells. When the experimental results were examined, the proposed methodologyshows utmost performance over average cell stiffness values for HCT116, andCTC-mimicked HCT116 cells were found as 1.08 kPa, and 0.88 kPa, respectively.The results confirm that CTC-mimicked HCT116 cells lose their adhesion abilityto enter the vascular circulation and metastasize. They also exhibit a softerstiffness profile compared to adherent forms of the cancer cells. Hence, theproposed technique is a significant, reliable, and faster alternative forin-vitro cell stiffness characterization tools. It can be utilized for variousapplications where single-cell analysis is required, such as disease modeling,drug testing, diagnostics, and many more