Osteosarcoma is a primary malignant tumor in adolescents, associated with high mortality and morbidity. The high-dose methotrexate (MTX) chemotherapy used to treat this disease may induce primary or secondary drug resistance, resulting in a reduced effect of comprehensive treatment. In this study, the relationship between reduced folate carrier (RFC) gene expression and intracellular drug conce...

In an attempt to study the roles of G-protein stimulatory subunit α (Gsα) in osteoblasts, we introduced an expression vector encoding Gsα into human osteoblastic cell line SaOS-2, and established the clones stably overexpressing Gsα (SaOS-2-Gsα). In SaOS-2-Gsα, the intracellular content of cyclic AMP (cAMP) was increased compared with the parental SaOS-2 cells. In addition, when treated with PT...

The aim of the present study was to investigate the underlying mechanisms of methotrexate (MTX) resistance in the human osteosarcoma cell line, Saos-2/MTX4.4, and to evaluate various methods of overcoming the resistance to this chemotherapeutic agent. MMT assays were performed to determine the resistance of the primary (Saos-2) and resistant (Saos-2/MTX4.4) cell lines to MTX, cisplatin [cis-dia...

We study set algebras with an operator (SAO) that satisfies the axioms of S5 knowledge. A necessary and sufficient condition is given for such SAOs that the knowledge operator is defined by a partition of the state space. SAOs are constructed for which the condition fails to hold. We conclude that no logic singles out the partitional SAOs among all SAOs.

Our previous study showed that exogenous human mesenchymal stem cells (hMSCs) targeted established osteosarcoma and promoted its growth and pulmonary metastasis in vivo. As a follow-up, the present study aimed to investigate how hMSCs would interact with Saos-2 through autocrine/paracrine communication. The results showed that co-injection of hMSCs with Saos-2 into the proximal tibia of nude mi...

introduction : deproteinized bovine bone mineral (bio-oss) is a xenogenic bone substitute, widely used in maxillofacial bone regeneration. the aim of this in vitro study was to investigate its influence on the growth behavior of human osteosarcoma cell line, saos-2 culture, and compare it with the physiologic dose of dexamethasone, an inductive factor for osteoblasts. materials and methods: hum...

This report includes an extended review of the contemporary inclusionary criteria used to identify children with suspected apraxia of speech (sAOS) and describes findings supporting a lexical stress marker for sAOS. The thesis is that although a deficit in speech praxis is the core disorder in sAOS, only a few diagnostic markers for sAOS assess this speech motor control construct. The proposed ...

We recently reported exchange of membrane and cytoplasmic markers between SAOS-2 osteosarcoma cells and human gingival fibroblasts (h-GF) without comparable exchange of nuclear markers, while similar h-GF exchange was seen for melanoma and ovarian carcinoma cells. This process of "cellular sipping" changes phenotype such that cells sharing markers of both SAOS-2 and h-GF have morphology interme...

The aim of this study was to evaluate and compare the cytotoxicity induced by two resin-based sealers, 2Seal and AH Plus, in two osteoblast-like cell lines, MG-63 and Saos-2. Using sterile discs of both sealers in complete media, 24- and 72-h extracts were prepared. The extracts were exchanged with Saos-2 or MG-63 cell culture media at 75% confluence, and after 24 h incubation, cell viability t...

Human osteosarcoma cell line SaOS-2 is an osteoblastic cell model that contains factors like bone morphogenetic proteins necessary for initiating bone formation. The cell line also expresses high levels of osteoinductive activity. In contrast to highly complicated and expensive ways to identify, purify, and separate specific bone-inducing agents from SaOS-2 cells, lysate can be used as an alter...