scholarly journals Inhibition of glycosphingolipid biosynthesis reverts multidrug resistance by differential modulation of ABC transporters on chronic myeloid leukemias

2020 ◽  
Author(s):  
Eduardo J. Salustiano ◽  
Kelli M. da Costa ◽  
Leonardo Freire-de-Lima ◽  
Lucia Mendonça-Previato ◽  
José O. Previato

ABSTRACTMultidrug resistance (MDR) in cancer manifests due to cross-resistance to chemotherapeutic drugs with neither structural nor functional relationship, markedly by increased expression and activity of ABC superfamily transporters. Evidences indicate sphingolipids as substrates to ABC proteins in processes such as cell signaling, membrane biosynthesis and inflammation, and products of its biosynthetic route were shown to favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key cell regulator enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Under stress, cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after assimilation into GlcCer by UGCG. Given that cancer cells seem to mobilize UGCG and increase GSL contents for the clearance of ceramides ultimately contributing to treatment failure, we studied how inhibiting GSL biosynthesis would affect the MDR phenotype of chronic myeloid leukemias. Results indicate that MDR associates to higher expression of UGCG and to a complex GSL profile. Inhibition of this glucosyltransferase greatly reduced GM1 expression, and cotreatment with standard chemotherapeutics sensitized cells leading to mitochondrial membrane potential loss and apoptosis. Despite reducing ABCB1 expression, only the ABCC-mediated efflux activity was affected. Consistently, efflux of C6-ceramide, one byproduct of UGCG downregulation, was reduced after inhibition of ABCC-mediated transport. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, overcoming drug resistance through distinct mechanisms. This work brings more comprehension about the involvement of GSL for chemotherapy failure, and modulation of its contents emerges as an intervention targeted to MDR leukemias.

2020 ◽  
Vol 295 (19) ◽  
pp. 6457-6471 ◽  
Author(s):  
Eduardo J. Salustiano ◽  
Kelli M. da Costa ◽  
Leonardo Freire-de-Lima ◽  
Lucia Mendonça-Previato ◽  
José O. Previato

Multidrug resistance (MDR) in cancer arises from cross-resistance to structurally- and functionally-divergent chemotherapeutic drugs. In particular, MDR is characterized by increased expression and activity of ATP-binding cassette (ABC) superfamily transporters. Sphingolipids are substrates of ABC proteins in cell signaling, membrane biosynthesis, and inflammation, for example, and their products can favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key regulatory enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Stressed cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after UGCG mediates incorporation into GlcCer. Given that cancer cells seem to mobilize UGCG and have increased GSL content for ceramide clearance, which ultimately contributes to chemotherapy failure, here we investigated how inhibition of GSL biosynthesis affects the MDR phenotype of chronic myeloid leukemias. We found that MDR is associated with higher UGCG expression and with a complex GSL profile. UGCG inhibition with the ceramide analog d-threo-1-(3,4,-ethylenedioxy)phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (EtDO-P4) greatly reduced GSL and monosialotetrahexosylganglioside levels, and co-treatment with standard chemotherapeutics sensitized cells to mitochondrial membrane potential loss and apoptosis. ABC subfamily B member 1 (ABCB1) expression was reduced, and ABCC-mediated efflux activity was modulated by competition with nonglycosylated ceramides. Consistently, inhibition of ABCC-mediated transport reduced the efflux of exogenous C6-ceramide. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, which typically overcomes drug resistance through distinct mechanisms. This work sheds light on the involvement of GSL in chemotherapy failure, and its findings suggest that targeted GSL modulation could help manage MDR leukemias.


2020 ◽  
Vol 27 ◽  
Author(s):  
Justyna Dłubek ◽  
Jacek Rysz ◽  
Zbigniew Jabłonowski ◽  
Anna Gluba-Brzózka ◽  
Beata Franczyk

: Prostate cancer is second most common cancer affecting male population all over the world. The existence of a correlation between lipid metabolism disorders and cancer of the prostate gland has been widely known for a long time. According to hypotheses, cholesterol may contribute to prostate cancer progression as a result of its participation as a signalling molecule in prostate growth and differentiation via numerous biologic mechanisms including Akt signalling and de novo steroidogenesis. The results of some studies suggest that increased cholesterol levels may be associated with higher risk of more aggressive course of disease. The aforementioned alterations in the synthesis of fatty acids are a unique feature of cancer and, therefore, it constitutes an attractive target for therapeutic intervention in the treatment of prostate cancer. Pharmacological or gene therapy aimed to reduce the activity of enzymes involved in de novo synthesis of fatty acids, FASN, ACLY (ATP citrate lyase) or SCD-1 (stearoyl-CoA desaturase) in particular, may result in cells growth arrest. Nevertheless, not all cancers are unequivocally associated with hypocholesterolaemia. It cannot be ruled out that the relationship between prostate cancer and lipid disorders is not a direct quantitative correlation between carcinogenesis and the amount of the circulating cholesterol. Perhaps the correspondence is more sophisticated and connected to the distribution of cholesterol fractions, or even sub-fractions of e.g. HDL cholesterol.


2021 ◽  
Vol 22 (4) ◽  
pp. 2127
Author(s):  
Jakub Suchodolski ◽  
Anna Krasowska

Candida albicans is a pathogenic fungus that is increasingly developing multidrug resistance (MDR), including resistance to azole drugs such as fluconazole (FLC). This is partially a result of the increased synthesis of membrane efflux transporters Cdr1p, Cdr2p, and Mdr1p. Although all these proteins can export FLC, only Cdr1p is expressed constitutively. In this study, the effect of elevated fructose, as a carbon source, on the MDR was evaluated. It was shown that fructose, elevated in the serum of diabetics, promotes FLC resistance. Using C. albicans strains with green fluorescent protein (GFP) tagged MDR transporters, it was determined that the FLC-resistance phenotype occurs as a result of Mdr1p activation and via the increased induction of higher Cdr1p levels. It was observed that fructose-grown C. albicans cells displayed a high efflux activity of both transporters as opposed to glucose-grown cells, which synthesize Cdr1p but not Mdr1p. Additionally, it was concluded that elevated fructose serum levels induce the de novo production of Mdr1p after 60 min. In combination with glucose, however, fructose induces Mdr1p production as soon as after 30 min. It is proposed that fructose may be one of the biochemical factors responsible for Mdr1p production in C. albicans cells.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Moein Dehbashi ◽  
Zohreh Hojati ◽  
Majid Motovali-bashi ◽  
Mazdak Ganjalikhani-Hakemi ◽  
Akihiro Shimosaka ◽  
...  

AbstractCancer recurrence presents a huge challenge in cancer patient management. Immune escape is a key mechanism of cancer progression and metastatic dissemination. CD25 is expressed in regulatory T (Treg) cells including tumor-infiltrating Treg cells (TI-Tregs). These cells specially activate and reinforce immune escape mechanism of cancers. The suppression of CD25/IL-2 interaction would be useful against Treg cells activation and ultimately immune escape of cancer. Here, software, web servers and databases were used, at which in silico designed small interfering RNAs (siRNAs), de novo designed peptides and virtual screened small molecules against CD25 were introduced for the prospect of eliminating cancer immune escape and obtaining successful treatment. We obtained siRNAs with low off-target effects. Further, small molecules based on the binding homology search in ligand and receptor similarity were introduced. Finally, the critical amino acids on CD25 were targeted by a de novo designed peptide with disulfide bond. Hence we introduced computational-based antagonists to lay a foundation for further in vitro and in vivo studies.


2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Jing-dong Zhou ◽  
Ting-juan Zhang ◽  
Zi-jun Xu ◽  
Zhao-qun Deng ◽  
Yu Gu ◽  
...  

AbstractThe potential mechanism of myelodysplastic syndromes (MDS) progressing to acute myeloid leukemia (AML) remains poorly elucidated. It has been proved that epigenetic alterations play crucial roles in the pathogenesis of cancer progression including MDS. However, fewer studies explored the whole-genome methylation alterations during MDS progression. Reduced representation bisulfite sequencing was conducted in four paired MDS/secondary AML (MDS/sAML) patients and intended to explore the underlying methylation-associated epigenetic drivers in MDS progression. In four paired MDS/sAML patients, cases at sAML stage exhibited significantly increased methylation level as compared with the matched MDS stage. A total of 1090 differentially methylated fragments (DMFs) (441 hypermethylated and 649 hypomethylated) were identified involving in MDS pathogenesis, whereas 103 DMFs (96 hypermethylated and 7 hypomethylated) were involved in MDS progression. Targeted bisulfite sequencing further identified that aberrant GFRA1, IRX1, NPY, and ZNF300 methylation were frequent events in an additional group of de novo MDS and AML patients, of which only ZNF300 methylation was associated with ZNF300 expression. Subsequently, ZNF300 hypermethylation in larger cohorts of de novo MDS and AML patients was confirmed by real-time quantitative methylation-specific PCR. It was illustrated that ZNF300 methylation could act as a potential biomarker for the diagnosis and prognosis in MDS and AML patients. Functional experiments demonstrated the anti-proliferative and pro-apoptotic role of ZNF300 overexpression in MDS-derived AML cell-line SKM-1. Collectively, genome-wide DNA hypermethylation were frequent events during MDS progression. Among these changes, ZNF300 methylation, a regulator of ZNF300 expression, acted as an epigenetic driver in MDS progression. These findings provided a theoretical basis for the usage of demethylation drugs in MDS patients against disease progression.


1990 ◽  
Vol 14 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Hiroshi Sato ◽  
Michael M. Gottesman ◽  
Lori J. Goldstein ◽  
Ira Pastan ◽  
Anne Marie Block ◽  
...  

1987 ◽  
Vol 7 (2) ◽  
pp. 718-724
Author(s):  
K L Deuchars ◽  
R P Du ◽  
M Naik ◽  
D Evernden-Porelle ◽  
N Kartner ◽  
...  

The overexpression of a plasma membrane glycoprotein, P-glycoprotein, is strongly correlated with the expression of multidrug resistance. This phenotype (frequently observed in cell lines selected for resistance to a single drug) is characterized by cross resistance to many drugs, some of which are used in cancer chemotherapy. In the present study we showed that DNA-mediated transformants of mouse LTA cells with DNA from multidrug-resistant hamster cells acquired the multidrug resistance phenotype, that the transformants contained hamster P-glycoprotein DNA sequences, that these sequences were amplified whereas the recipient mouse P-glycoprotein sequences remained at wild-type levels, and that the overexpressed P-glycoprotein in these cells was of hamster origin. Furthermore, we showed that the hamster P-glycoprotein sequences were transfected independently of a group of genes that were originally coamplified and linked within a 1-megabase-pair region in the donor hamster genome. These data indicate that the high expression of P-glycoprotein is the only alteration required to mediate multidrug resistance.


2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Priyanka Panwar ◽  
Kepa K. Burusco ◽  
Muna Abubaker ◽  
Holly Matthews ◽  
Andrey Gutnov ◽  
...  

ABSTRACT Drug repositioning offers an effective alternative to de novo drug design to tackle the urgent need for novel antimalarial treatments. The antiamoebic compound emetine dihydrochloride has been identified as a potent in vitro inhibitor of the multidrug-resistant strain K1 of Plasmodium falciparum (50% inhibitory concentration [IC50], 47 nM ± 2.1 nM [mean ± standard deviation]). Dehydroemetine, a synthetic analogue of emetine dihydrochloride, has been reported to have less-cardiotoxic effects than emetine. The structures of two diastereomers of dehydroemetine were modeled on the published emetine binding site on the cryo-electron microscopy (cryo-EM) structure with PDB code 3J7A (P. falciparum 80S ribosome in complex with emetine), and it was found that (−)-R,S-dehydroemetine mimicked the bound pose of emetine more closely than did (−)-S,S-dehydroisoemetine. (−)-R,S-dehydroemetine (IC50 71.03 ± 6.1 nM) was also found to be highly potent against the multidrug-resistant K1 strain of P. falciparum compared with (−)-S,S-dehydroisoemetine (IC50, 2.07 ± 0.26 μM), which loses its potency due to the change of configuration at C-1′. In addition to its effect on the asexual erythrocytic stages of P. falciparum, the compound exhibited gametocidal properties with no cross-resistance against any of the multidrug-resistant strains tested. Drug interaction studies showed (−)-R,S-dehydroemetine to have synergistic antimalarial activity with atovaquone and proguanil. Emetine dihydrochloride and (−)-R,S-dehydroemetine failed to show any inhibition of the hERG potassium channel and displayed activity affecting the mitochondrial membrane potential, indicating a possible multimodal mechanism of action.


EMBO Reports ◽  
2019 ◽  
Vol 20 (10) ◽  
Author(s):  
Yang Zhang ◽  
Chenchen Li ◽  
Chuanzhen Hu ◽  
Qian Wu ◽  
Yongping Cai ◽  
...  

2020 ◽  
Vol 48 (9) ◽  
pp. 4741-4755
Author(s):  
Steven Kregel ◽  
Pia Bagamasbad ◽  
Shihan He ◽  
Elizabeth LaPensee ◽  
Yemi Raji ◽  
...  

Abstract Androgen receptor (AR) action is a hallmark of prostate cancer (PCa) with androgen deprivation being standard therapy. Yet, resistance arises and aberrant AR signaling promotes disease. We sought compounds that inhibited genes driving cancer but not normal growth and hypothesized that genes with consensus androgen response elements (cAREs) drive proliferation but genes with selective elements (sAREs) promote differentiation. In a high-throughput promoter-dependent drug screen, doxorubicin (dox) exhibited this ability, acting on DNA rather than AR. This dox effect was observed at low doses for multiple AR target genes in multiple PCa cell lines and also occurred in vivo. Transcriptomic analyses revealed that low dox downregulated cell cycle genes while high dox upregulated DNA damage response genes. In chromatin immunoprecipitation (ChIP) assays with low dox, AR binding to sARE-containing enhancers increased, whereas AR was lost from cAREs. Further, ChIP-seq analysis revealed a subset of genes for which AR binding in low dox increased at pre-existing sites that included sites for prostate-specific factors such as FOXA1. AR dependence on cofactors at sAREs may be the basis for differential modulation by dox that preserves expression of genes for survival but not cancer progression. Repurposing of dox may provide unique opportunities for PCa treatment.


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