MiR-382-5p’s Function as a Suppressor in Osteosarcoma (OS) by Targeting PDPK1

ABSTRACT miR-382-5p engages in development of osteosarcoma (OS). However, the regulatory system of miR-382-5p in osteosarcoma remains to be revealed. This research studied the interplay between PDPK1 and miR- 382-5p in OS. RT-PCR was used to evaluate miR-382-5p and PDPK1 expression in OS cells and normal human osteoblast cells. Dual-luciferase reporter assay validated PDPK1 as a miR-382-5p target. CCK-8 evaluated the cell viability. Flow cytometric method determined cell apoptosis rate. Transwell and Scratch assays estimated the cell metastasis. miR-382-5p was inhibited in OS cells. Further functional results showed miR-382-5p upregulation reduced cell viability, and mobility by mediating PDPK1 in OS cells

α-Mangostin Induces Apoptosis in Human Osteosarcoma Cells Through ROS-Mediated Endoplasmic Reticulum Stress via the WNT Pathway

α-mangostin has been confirmed to promote the apoptosis of MG-63 cells, but its specific pro-apoptosis mechanism in osteosarcoma (OS) remains further investigation. Here, we demonstrated that α-mangostin restrained the viability of OS cells (143B and Saos-2), but had little effect on the growth of normal human osteoblast. α-mangostin increased OS cell apoptosis by activating the caspase-3/8 cascade. Besides, α-mangostin induced endoplasmic reticulum (ER) stress and restrained the Wnt/β-catenin pathway activity. 4PBA (an ER stress inhibitor) or LiCl (an effective Wnt activator) treatment effectively hindered α-mangostin-induced apoptosis and the caspase-3/8 cascade. Furthermore, we also found that α-mangostin induced ER stress by promoting ROS production. And ER stress-mediated apoptosis caused by ROS accumulation depended on the inactivation of Wnt/β-catenin pathway. In addition, α-mangostin significantly hindered the growth of xenograft tumors, induced the expression of ER stress marker proteins and activation of the caspase-3/8 cascade, and restrained the Wnt/β-catenin signaling in vivo. In short, ROS-mediated ER stress was involved in α-mangostin triggered apoptosis, which might depended on Wnt/β-catenin signaling inactivation.

Osteoblast adhesion and proliferation on porous chitosan/polycaprolactone scaffolds for bone tissue engineering application

Tissue engineering is an evolving technique to reduce the limitations of the bone graft. It provides diversity to improve the healing process of bone fractures and defect by combining the use of 3D scaffolds, healing promoting factors, gene therapy and different drugs. Flexibility to use a different technique to fabricate scaffolds lead to the new insight into bone healing future. A bone graft is defined as promoted bone healing through osteogenesis, osteoinduction, and osteoconduction by the implanted material alone or with other materials. Ideal bone graft depends on several factors such as biomechanical characteristic, tissue viability, the morphological structure as well as biological characteristics. In this work, we have investigated adhesion, proliferation, and differentiation of poly (ɛ-caprolactone) / chitosan scaffolds with the incorporation of hydroxyapatite and tetracycline HCl on normal human osteoblast cells. Both of the polymers were blended without a cross-linking agent to form porous scaffolds by freeze-drying technique. From the results, it was observed that the compressive modulus increased from 4.0 MPa to 12.5 MPa and the yield strength increased from 0.48 MPa to 0.75 MPa for the PCL/CS scaffold and nHA/PCL/CS scaffold, respectively. Scanning electron microscopy study revealed that the cells successfully adhered to the surface of scaffolds after 24 hours incubation. Proliferation analysis exhibited the increasing trend of growth of cells. This study indicated that the scaffold fabricated using this technique was able to promote adhesion, proliferation, and differentiation of normal human osteoblast cells.

Adhesion and Cell Viability of Normal Human Osteoblasts (NHOst) on Scaffolds of Poly (3-hydroxybutyrate)

ABSTRACTBiodegradable Normal Human Osteoblast (NHOst) cells were inoculated into the polymer scaffolds of poly(β-hydroxybutyrate) (PHB) obtained from a specially developed strain of Azotobacter vinelandii. Cell adhesion is essential to promote growth on scaffolds for tissue engineering. Thus, in this research we focused on the adhesion of osteoblast cells to PHB scaffolds produced by solution casting and electrospinning. Cell viability was also investigated up to 168 hrs. Water contact angle on the PHB scaffolds was determined prior to the cells inoculation. The contact angle is usually related to the ability of different cell strains to adhere to a given material. The as cast film exhibited a contact angle α=72° whereas for the electrospun membrane α=102°, thus in theory cell adhesion would be greater for the cast film. Biological testing was carried out on plates of 24 wells; cell viability was determined by Trypan Blue, cell morphology by optical microscopy, and cell nuclei integrity by staining with Acridine orange. Parallel studies were carried out on control (empty) wells. Microscopy observations 168 hrs after cell inoculation showed larger quantities of osteoblast cells in the wells containing PHB scaffolds and the cell nuclei were still active. Moreover, it was found that the cells grew inside the PHB scaffolds and the cell viability was slightly greater for the electrospun scaffold. Interestingly, the time to remove the cells from the scaffolds (film and membranes) was increasing function of the cell culture time, therefore suggesting that PHB promotes adhesion of Normal Human Osteoblast cells to its surface.