Sections from formalin-fixed paraffin-embedded tumor blocks from 52 neuroblastoma cases (17 with localized, 35 with advanced disease) were subjected to immunohistochemistry for P-gp and GST-pi expressions.
Expression of N-myc, c-myc, and MDR-1 proteins in newly established neuroblastoma cell lines: a study by immunofluorescence staining and flow cytometry.
Lovastatin, a nonreversible inhibitor of HMG-CoA reductase, induced extensive cytotoxicity that was restricted to drug-resistant P-glycoprotein-expressing neuroblastoma cell lines.
Study of the mechanisms underlying the reversal of multidrug resistance of human neuroblastoma multidrug-resistant cell line SK-N-SH/MDR1 by low-intensity pulsed ultrasound.
A panel of monoclonal antibodies (MAbs) to P-glycoprotein was developed by immunization of mice with multidrug-resistant human neuroepithelioma and neuroblastoma cells.
We conclude that most neuroblastoma cell lines are sensitive to YM155 in the low nM range and that resistant cells can be sensitised by ABCB1 inhibitors.
Here, we demonstrate upregulation of multidrug transporters ABCB1 and ABCG2 as a major mode of resistance to THZ1, a covalent inhibitor of CDKs 7, 12, and 13 in neuroblastoma and lung cancer.
The results show that BS-RNase selectively kills NB cells by inducing apoptosis and that this agent is active against mdr-1 expressing cells both in vitro and in vivo.
Combination therapy showed a synergistic activity between doxorubicin and either bioconjugate or nanocarrier on BE(2)C. More interestingly, on BE(2)C/ADR we recorded both the reversion of doxorubicin resistance mechanism as a consequence of decreased P-gp expression (Western Blot analysis) and a synergistic effect on cell viability, confirming the proposed nanohybrid as a very promising starting point for further research in neuroblastoma treatment.
Multidrug resistance protein 1 has been previously implicated in the development of drug resistance, particularly with regard to influencing clinical outcomes in neuroblastoma.
Here, we present the effect of the N-(2-hydroxypropyl) methacrylamide-based polymer conjugate with P-gp inhibitor ritonavir (RIT) on the increase of free doxorubicin (DOX) and polymer-bound DOX cytotoxicity in the human neuroblastoma 4 cell line and its resistant clones to different cytostatics.
Data from present study suggest that transcriptional inactivation of MDR1 gene due to increased MDR1 promoter methylation may be a contributing factor in pathogenesis and progression of neuroblastoma tumors, and may be used in designing an effective treatment therapy to neuroblastoma patients.
Data from present study suggest that transcriptional inactivation of MDR1 gene due to increased MDR1 promoter methylation may be a contributing factor in pathogenesis and progression of neuroblastoma tumors, and may be used in designing an effective treatment therapy to neuroblastoma patients.
To this end, we used an inducible siRNA (small interfering RNA) expression system to silence the expression of MRP1 and MDR1 in human neuroblastoma SH-SY5Y cells.
To rule out the possibility that multidrug resistance (MDR) genes are involved in development of acquired drug resistance in murine neuroblastoma (rMNB/MDL) cells made resistant to MDL, the expression of Mdr1a, Mdr1b, Mdr2 (multidrug resistance/P-glycoprotein), and Mrp-1 (multidrug resistance associated protein) was examined in rMNB-MDL cells.
Though Pgp expression is detectable and functional in neuroblastoma cells, but its presence does not provide much information to the complex phenomenon of chemotherapy resistance in patients.
A similar strong association has been observed between the expression of P-glycoprotein and outcome of treatment in certain malignancies in children, such as neuroblastoma, rhabdomyosarcoma, and acute lymphoblastic leukemia.
Decreased expression of the N-myc oncogene in neuroblastoma cell lines SH-SY5Y and BE(2)-C, following treatment with retinoic acid, was paralleled by down-regulation of MRP gene expression, contrasting with increased expression of the MDR1 gene.
The purpose of this study was to determine the activity of pyrazoloacridine (PZA) in neuroblastomas that have acquired high-level resistance to multiple drugs (not associated with multidrug resistance-associated protein or P-glycoprotein) during therapy, including those with loss of p53 function.