MEK Inhibition Sensitizes Precursor B-Cell Acute Lymphoblastic Leukemia (B-ALL) Cells to Dexamethasone through Modulation of mTOR Activity and Stimulation of Autophagy
PBN-AR
Instytucja
Centrum Nowych Technologii UW (Uniwersytet Warszawski)
Informacje podstawowe
Główny język publikacji
en
Czasopismo
PLoS One
ISSN
1932-6203
EISSN
Wydawca
PUBLIC LIBRARY SCIENCE
DOI
URL
Rok publikacji
2016
Numer zeszytu
5
Strony od-do
0155893
Numer tomu
11
Identyfikator DOI
Liczba arkuszy
Autorzy
(liczba autorów: 17)
Pozostali autorzy
+ 16
Open access
Tryb otwartego dostępu
Otwarte czasopismo
Wersja tekstu w otwartym dostępie
Wersja opublikowana
Licencja otwartego dostępu
Creative Commons — Uznanie autorstwa
Czas opublikowania w otwartym dostępie
Razem z publikacją
Data udostępnienia w sposób otwarty
Streszczenia
Język
en
Treść
Resistance to glucocorticosteroids (GCs) is a major adverse prognostic factor in B-ALL, but the molecular mechanisms leading to GC resistance are not completely understood. Herein, we sought to elucidate the molecular background of GC resistance in B-ALL and characterize the therapeutic potential of targeted intervention in these mechanisms. Using exploratory bioinformatic approaches, we found that resistant cells exhibited significantly higher expression of MEK/ERK (MAPK) pathway components. We found that GC-resistant ALL cell lines had markedly higher baseline activity of MEK and small-molecule MEK1/2 inhibitor selumetinib increased GCs-induced cell death. MEK inhibitor similarly increased in vitro dexamethasone activity in primary ALL blasts from 19 of 22 tested patients. To further confirm these observations, we overexpressed a constitutively active MEK mutant in GC-sensitive cells and found that forced MEK activity induced resistance to dexamethasone. Since recent studies highlight the role GC-induced autophagy upstream of apoptotic cell death, we assessed LC3 processing, MDC staining and GFP-LC3 relocalization in cells incubated with either DEX, SEL or combination of drugs. Unlike either drug alone, only their combination markedly increased these markers of autophagy. These changes were associated with decreased mTOR activity and blocked 4E-BP1 phosphorylation. In cells with silenced beclin-1 (BCN1), required for autophagosome formation, the synergy of DEX and SEL was markedly reduced. Taken together, we show that MEK inhibitor selumetinib enhances dexamethasone toxicity in GC-resistant B-ALL cells. The underlying mechanism of this interaction involves inhibition of mTOR signaling pathway and modulation of autophagy markers, likely reflecting induction of this process and required for cell death. Thus, our data demonstrate that modulation of MEK/ERK pathway is an attractive therapeutic strategy overcoming GC resistance in B-ALL patients.
Cechy publikacji
REVIEW_ARTICLE
Inne
System-identifier
735717
CrossrefMetadata from Crossref logo
Cytowania
Liczba prac cytujących tę pracę
Brak danych
Referencje
Liczba prac cytowanych przez tę pracę
Brak danych