Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Azacitidine (AZA) is the current treatment for patients with high-risk myelodysplastic syndrome, but resistance is a common feature of AZA-treated patients. To investigate the mechanisms associated with AZA resistance in vitro, we generated AZA-resistant SKM1 myeloid cells, called hereafter AZA-R. AZA-R cells exhibit impaired mitochondrial membrane permeabilization and caspase activation in response to AZA compared to their AZA-sensitive (AZA-S) counterpart. AZA induced LC3-II accumulation and cathepsin B activity in AZA-S cells, two hallmarks of autophagy. AZA-R cells displayed increased basal autophagy but are resistant to AZA-mediated autophagy. Inhibition of autophagy using LC3 siRNA revealed that autophagy is protective in AZA-S cells and AZA-R cells in basal conditions. By contrast, AZA-R cells exhibited impaired autophagy in response to AZA. Collectively, our findings indicate that AZA promotes apoptosis and autophagy in SKM1 cells, and that AZA-R cells are resistant to both apoptosis and autophagy induced by AZA.
 ...
PMID:Azacitidine-resistant SKM1 myeloid cells are defective for AZA-induced mitochondrial apoptosis and autophagy. 2186 99

Azacitidine is the leading compound to treat patients suffering myelodysplastic syndrome (MDS) or AML with less than 30% of blasts, but a majority of patients is primary refractory or rapidly relapses under treatment. These patients have a drastically reduced life expectancy as compared to sensitive patients. Therefore identifying predictive factors for AZA resistance is of great interest to propose alternative therapeutic strategies for non-responsive patients. We generated AZA-resistant myeloid cell line (SKM1-R) that exhibited increased expression of BCL2L10 an anti-apoptotic Bcl-2 member. Importantly, BCL2L10 knockdown sensitized SKM1-R cells to AZA effect suggesting that increased BCL2L10 expression is linked to AZA resistance in SKM1-R. We next established in 77 MDS patients that resistance to AZA is significantly correlated with the percentage of MDS or AML cells expressing BCL2L10. In addition, we showed that the proportion of BCL2L10 positive bone marrow cells can predict overall survival in MDS or AML patients. We propose a convenient assay in which the percentage of BCL2L10 expressing cells as assessed by flow cytometry is predictive of whether or not a patient will become resistant to AZA. Therefore, systematic determination of BCL2L10 expression could be of great interest in newly diagnosed and AZA-treated MDS patients.
 ...
PMID:BCL2L10 is a predictive factor for resistance to azacitidine in MDS and AML patients. 2257 54

In the present study, we provide a comparative phenotypic and genotypic analysis of azacitidine-sensitive and resistant SKM-1 cell lines. Morphologically, SKM1-R exhibited increase in cell size that accounts for by enhanced ploidy in a majority of cells as shown by cell cycle and karyotype analysis. No specific Single Nucleotide Polymorphism (SNP) alteration was found in SKM1-R cells compared to their SKM1-S counterpart. Comparative pangenomic profiling revealed the up-regulation of a panel of genes involved in cellular movement, cell death and survival and down-regulation of genes required for cell to cell signaling and free radical scavenging in SKM1-R cells. We also searched for mutations frequently associated with myelodysplastic syndromes (MDS) and found that both cell lines harbored mutations in TET2, ASLX1 and TP53. Collectively, our data show that despite their different morphological and phenotypic features, SKM1-S and SKM1-R cells exhibited similar genotypic characteristics. Finally, pangenomic profiling identifies new potential pathways to be targeted to circumvent AZA-resistance. In conclusion, SKM1-R cells represent a valuable tool for the validation of new therapeutic intervention in MDS.
...
PMID:Phenotypic and genotypic characterization of azacitidine-sensitive and resistant SKM1 myeloid cell lines. 2496 89

A series of nucleoside analogues bearing a 1,4,5-trisubstituted-1,2,3-triazole aglycone was synthesized using a straightforward click/electrophilic addition or click/oxidative coupling tandem procedures. SAR analysis, using cell culture assays, led to the discovery of a series of compounds belonging to the 5-alkynyl-1,2,3-triazole family that exhibits potent antileukemic effects on several hematologic malignancies including chronic myeloid leukemia (CML) and myelodysplastic syndromes (MDS) either sensitive or resistant to their respective therapy. Compound 4a also proved efficient in vivo on mice xenografted with SKM1-R MDS cell line. Additionally, some insights in its mode of action revealed that this compound induced cell death by caspase and autophagy induction.
 ...
PMID:In Vitro and in Vivo Evaluation of Fully Substituted (5-(3-Ethoxy-3-oxopropynyl)-4-(ethoxycarbonyl)-1,2,3-triazolyl-glycosides as Original Nucleoside Analogues to Circumvent Resistance in Myeloid Malignancies. 2809 38