Search results for "osteosarcoma"

Porous titania surfaces on titanium with hierarchical macro- and mesoporosities for enhancing cell adhesion, proliferation and mineralization

2014

Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5 μm. An additional mesoporous titania top layer following the contour of the macropores, of 100-200 nm thickness and with a pore diameter of 10nm, was formed by using the evaporation-induced self-assembly (EISA) method with titanium (IV) tetraethoxide as the precursor. A coherent laminar titania surface layer was thus obtained, creating a hierarchical macro- and mesoporous surface that was characterized by high-resolution electron microscopy. The interfacial bonding between the surface layers and the titanium matrix was characterized by the scratch test that con…

Isolated osteoblastoma of the cuboid bone: A case report and review of the literature

2020

Osteoblastoma is a relatively rare, benign, bone-forming tumor, commonly observed in the second and third decades of life. Spine and the long tubular bones are the most common sites of involvement. Osteoblastoma is infrequently seen in other sites, including the bones of hand and foot. A rare case of a 35-year-old man that presented an osteoblastoma of the cuboid bone is reported. The patient was treated with surgical resection and grafting. After the intervention, the patient recovered with no clinical and radiological evidence of recurrence after one year of follow-up. Several cases of osteoblastoma-like variant of osteosarcoma of the cuboid have been previously reported, but, to our know…

pRb suppresses camptothecin-induced apoptosis in human osteosarcoma Saos-2 cells by inhibiting c-Jun N-terminal kinase

2001

AbstractThis paper studies the cytotoxic effect induced by the topoisomerase I inhibitor camptothecin in human osteosarcoma Saos-2 cells, which lack p53 and contain a non-functional form of the product of the retinoblastoma gene, pRb. Cytotoxicity induced by camptothecin was dose- and time-dependent; the treatment with 100 nM camptothecin reduced cell viability by 50% at 32 h and by 75% at 72 h of exposure. The cytotoxic effect was caused by apoptosis, as ascertained by morphological evidence, acridine orange-ethidium bromide staining and flow cytometric analysis. Apoptosis was accompanied by both the activation of caspase-3 and the fragmentation of poly(ADP-ribose) polymerase. Treatment wi…

Let-7d miRNA Shows Both Antioncogenic and Oncogenic Functions in Osteosarcoma-Derived 3AB-OS Cancer Stem Cells

2015

Osteosarcoma (OS), an aggressive highly invasive and metastatic bone-malignancy, shows therapy resistance and recurrence, two features that likely depend on cancer stem cells (CSCs), which hold both self-renewing and malignant potential. So, effective anticancer therapies against OS should specifically target and destroy CSCs. We previously found that the let-7d microRNA was downregulated in the 3AB-OS-CSCs, derived from the human OS-MG63 cells. Here, we aimed to assess whether let-7d modulation affected tumorigenic and stemness properties of these OS-CSCs. We found that let-7d-overexpression reduced cell proliferation by decreasing CCND2 and E2F2 cell-cycle-activators and increasing p21 an…

Induction of apoptosis in human osteosarcoma Saos-2 cells by the proteasome inhibitor MG132 and the protective effect of pRb

2003

Induction of apoptosis in human osteosarcoma Saos-2 cells by the proteasome inhibitor MG132 and the protective effect of pRb

Insights of Tris(2-pyridylmethyl)amine as anti-tumor agent for osteosarcoma: experimental and in silico studies

2021

Abstract Osteosarcoma (OS) is a malignant bone tumor and its occurrence is associated with high levels of microRNAs (miRNAs) and critical protein sinvolved on intracellular signaling pathways. Cisplatin and Doxorubicin are employed on chemotherapy, but their use cause side effects and contributes to multidrug resistance. Since several tripodal amines have been studied as anticancer agents, tris(2-pyridylmethyl)amine (TPA) was investigated against osteosarcoma cells. Here we show that TPA exhibits activity against MG-63 and Saos-2 cells. Cyclic voltammetry results indicate an interaction between TPA and dsDNA, denoted by blocking of the proton-assisted reduction of the 2-pyridylmethyl moiety…

Ultrasounds effects on osteosarcoma cell line (MG63) with double frequency and direction of sonication

2019

MicroRNA-29b-1 impairs in vitro cell proliferation, self‑renewal and chemoresistance of human osteosarcoma 3AB-OS cancer stem cells

2014

Osteosarcoma (OS) is the most common type of bone cancer, with a peak incidence in the early childhood. Emerging evidence suggests that treatments targeting cancer stem cells (CSCs) within a tumor can halt cancer and improve patient survival. MicroRNAs (miRNAs) have been implicated in the maintenance of the CSC phenotype, thus, identification of CSC-related miRNAs would provide information for a better understanding of CSCs. Downregulation of miRNA-29 family members (miR-29a/b/c; miR‑29s) was observed in human OS, however, little is known about the functions of miR-29s in human OS CSCs. Previously, during the characterization of 3AB-OS cells, a CSC line selected from human OS MG63 cells, we…

Genetic and Molecular Characterization of The Human Osteosarcoma 3AB-OS Cancer Stem Cell Line: A Possible Model For Studying Osteosarcoma Origin and …

2013

Finding new treatments targeting cancer stem cells (CSCs) within a tumor seems to be critical to halt cancer and improve patient survival. Osteosarcoma is an aggressive tumor affecting adolescents, for which there is no second-line chemotherapy. Uncovering new molecular mechanisms underlying the development of osteosarcoma and origin of CSCs is crucial to identify new possible therapeutic strategies. Here, we aimed to characterize genetically and molecularly the human osteosarcoma 3AB-OS CSC line, previously selected from MG63 cells and which proved to have both in vitro and in vivo features of CSCs. Classic cytogenetic studies demonstrated that 3AB-OS cells have hypertriploid karyotype wit…

WRN protects against topo I but not topo II inhibitors by preventing DNA break formation

2008

The Werner syndrome helicase/3′-exonuclease (WRN) is a major component of the DNA repair and replication machinery. To analyze whether WRN is involved in the repair of topoisomerase-induced DNA damage we utilized U2-OS cells, in which WRN is stably down-regulated (wrn-kd), and the corresponding wild-type cells (wrn-wt). We show that cells not expressing WRN are hypersensitive to the toxic effect of the topoisomerase I inhibitor topotecan, but not to the topoisomerase II inhibitor etoposide. This was shown by mass survival assays, colony formation and induction of apoptosis. Upon topotecan treatment WRN deficient cells showed enhanced DNA replication inhibition and S-phase arrest, whereas af…