Together, these experiments provide preclinical evidence that the FDA-approved DNA methylation inhibitor DAC may be repurposed to treat patients with osteosarcoma based on its efficacy to decrease proliferation, to induce osteoblast differentiation, and to reduce metastasis to visceral organs.<b>Significance:</b> These findings describe the effects of DNA methyltransferase inhibition on ERα and its potential role as a tumor suppressor in osteosarcoma.<i>See related commentary by Roberts, p. 1034</i><i>See related article by El Ayachi and colleagues; Cancer Res 79(5);982-93</i>.
To construct a stable RECQL5 overexpression osteosarcoma cell line (MG-63-RECQL5), RECQL5 gene was inserted into the human AAVS1 safe harbor by CRISPR/Cas9 system.
As a result, the miRNA-TF-mRNA regulatory network, including 1049 nodes (516 miRNA, 25 TFs, and 508 DEGs) and 15942 edges (interaction relationships, such as Pparg-Abca1 and miR-590-3p-AXIN2), was constructed, from which three significant modules were extracted and modules 2 and 3 contained interactions between miRNAs/TFs and DEGs such as miR-103-3p-<i>AXIN2</i>, miR-124-3p-<i>AR</i>-<i>Tgfb1i1</i>, and miR-27a-3p-<i>PPARG</i>-<i>Abca1</i>. miR-27a-3p was a known miRNA associated with OS.
In this study the U2OS human osteosarcoma cell line and its multidrug resistant (MDR) subline that overexpresses MDR-1 gene, MDR-U2OS, have been analyzed for their responsiveness to TRAIL.
Several studies have demonstrated that the major cause for doxorubicin resistance in osteosarcoma is the increased expression of the drug efflux transporter ABCB1/P-glycoprotein (Pgp).
Combining GRP78 suppression and MK2206-induced Akt inhibition decreases doxorubicin-induced P-glycoprotein expression and mitigates chemoresistance in human osteosarcoma.
Nuclear expression of the Y-box-binding protein (YB-1) has been reported to correlate with the expression of P-glycoprotein in breast cancer and osteosarcoma.
The present evidence indicated that there was no association between p-glycoprotein expression and chemotherapy response in patients with osteosarcoma.
Overall, our results elucidated for the first time that TIPE2 sensitizes osteosarcoma cells to cis-platin through downregulation of MDR1 and may be a novel target in osteosarcoma therapy.
The goal of this study was to establish human FK228-resistant osteosarcoma cell lines and to investigate whether there are mechanisms of FK228 resistance in addition to P-gp up-regulation.
Moreover, we assessed the expression of P-gp after suppressing ASS1 in Dox-sensitive cells (MCF-7 and KHOS) and after transfecting ASS1 into Dox-resistant cells (ES-X, VAESBJ, ASPS-KY and KHOSR2).