E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway
Arsenic trioxide (ATO) is a strong inducer of apoptosis in malignant hematological cells. Inducible phosphatidyl inositol 3 kinase (PI3K)-Akt activation promotes resistance to ATO. In the present study, we evaluated whether E3 ubiquitin ligase Cbl-b, a negative regulator of PI3K activation, is involved in the action of ATO. The effect of ATO on cell viability was measured by the Trypan blue exclusion assay or by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was determined by flow cytometry and protein expression was assayed by Western blotting. ATO decreased the viability of HL60 cells and induced cellular apoptosis, which was accompanied by transient activation of Akt. The PI3K/Akt inhibitor, LY294002, significantly increased ATO-induced apoptosis (P < 0.05). In addition, ATO up-regulated the expression of Cbl-b proteins. Furthermore, ATO inhibited cell viability with an IC50 of 18.54 μM at 24 h in rat basophilic leukemia-2H3 cells. ATO induced cellular apoptosis with transient activation of Akt and Cbl-b was also up-regulated. Rat basophilic leukemia-2H3 cells transfected with a dominant negative (DN) Cbl-b mutation showed overexpression of Cbl-b (DN) and enhanced Akt activation. Compared with cells transfected with vector, ATO-induced apoptosis was decreased and G2/M phase cells were increased at the same concentration (P < 0.05). The PI3K/Akt inhibitor, LY294002, re-sensitized Cbl-b (DN) overexpressing cells to ATO and reversed G2/M arrest (P < 0.05). Taken together, these results suggest that Cbl-b potentiates the apoptotic action of ATO by inhibition of the PI3K/Akt pathway.
Main Authors: | , , , , , , , , |
---|---|
Format: | Digital revista |
Language: | English |
Published: |
Associação Brasileira de Divulgação Científica
2011
|
Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000200004 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
id |
oai:scielo:S0100-879X2011000200004 |
---|---|
record_format |
ojs |
spelling |
oai:scielo:S0100-879X20110002000042011-02-04E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathwayYingchun,LiXiujuan,QuJinglei,QuYe,ZhangJing,LiuYuee,TengXuejun,HuKezuo,HouYunpeng,Liu Arsenic trioxide Apoptosis Cbl-b PI3K/Akt pathway Arsenic trioxide (ATO) is a strong inducer of apoptosis in malignant hematological cells. Inducible phosphatidyl inositol 3 kinase (PI3K)-Akt activation promotes resistance to ATO. In the present study, we evaluated whether E3 ubiquitin ligase Cbl-b, a negative regulator of PI3K activation, is involved in the action of ATO. The effect of ATO on cell viability was measured by the Trypan blue exclusion assay or by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was determined by flow cytometry and protein expression was assayed by Western blotting. ATO decreased the viability of HL60 cells and induced cellular apoptosis, which was accompanied by transient activation of Akt. The PI3K/Akt inhibitor, LY294002, significantly increased ATO-induced apoptosis (P < 0.05). In addition, ATO up-regulated the expression of Cbl-b proteins. Furthermore, ATO inhibited cell viability with an IC50 of 18.54 μM at 24 h in rat basophilic leukemia-2H3 cells. ATO induced cellular apoptosis with transient activation of Akt and Cbl-b was also up-regulated. Rat basophilic leukemia-2H3 cells transfected with a dominant negative (DN) Cbl-b mutation showed overexpression of Cbl-b (DN) and enhanced Akt activation. Compared with cells transfected with vector, ATO-induced apoptosis was decreased and G2/M phase cells were increased at the same concentration (P < 0.05). The PI3K/Akt inhibitor, LY294002, re-sensitized Cbl-b (DN) overexpressing cells to ATO and reversed G2/M arrest (P < 0.05). Taken together, these results suggest that Cbl-b potentiates the apoptotic action of ATO by inhibition of the PI3K/Akt pathway.info:eu-repo/semantics/openAccessAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research v.44 n.2 20112011-02-01info:eu-repo/semantics/articletext/htmlhttp://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000200004en10.1590/S0100-879X2010007500142 |
institution |
SCIELO |
collection |
OJS |
country |
Brasil |
countrycode |
BR |
component |
Revista |
access |
En linea |
databasecode |
rev-scielo-br |
tag |
revista |
region |
America del Sur |
libraryname |
SciELO |
language |
English |
format |
Digital |
author |
Yingchun,Li Xiujuan,Qu Jinglei,Qu Ye,Zhang Jing,Liu Yuee,Teng Xuejun,Hu Kezuo,Hou Yunpeng,Liu |
spellingShingle |
Yingchun,Li Xiujuan,Qu Jinglei,Qu Ye,Zhang Jing,Liu Yuee,Teng Xuejun,Hu Kezuo,Hou Yunpeng,Liu E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway |
author_facet |
Yingchun,Li Xiujuan,Qu Jinglei,Qu Ye,Zhang Jing,Liu Yuee,Teng Xuejun,Hu Kezuo,Hou Yunpeng,Liu |
author_sort |
Yingchun,Li |
title |
E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway |
title_short |
E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway |
title_full |
E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway |
title_fullStr |
E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway |
title_full_unstemmed |
E3 ubiquitin ligase Cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the PI3K/Akt pathway |
title_sort |
e3 ubiquitin ligase cbl-b potentiates the apoptotic action of arsenic trioxide by inhibiting the pi3k/akt pathway |
description |
Arsenic trioxide (ATO) is a strong inducer of apoptosis in malignant hematological cells. Inducible phosphatidyl inositol 3 kinase (PI3K)-Akt activation promotes resistance to ATO. In the present study, we evaluated whether E3 ubiquitin ligase Cbl-b, a negative regulator of PI3K activation, is involved in the action of ATO. The effect of ATO on cell viability was measured by the Trypan blue exclusion assay or by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was determined by flow cytometry and protein expression was assayed by Western blotting. ATO decreased the viability of HL60 cells and induced cellular apoptosis, which was accompanied by transient activation of Akt. The PI3K/Akt inhibitor, LY294002, significantly increased ATO-induced apoptosis (P < 0.05). In addition, ATO up-regulated the expression of Cbl-b proteins. Furthermore, ATO inhibited cell viability with an IC50 of 18.54 μM at 24 h in rat basophilic leukemia-2H3 cells. ATO induced cellular apoptosis with transient activation of Akt and Cbl-b was also up-regulated. Rat basophilic leukemia-2H3 cells transfected with a dominant negative (DN) Cbl-b mutation showed overexpression of Cbl-b (DN) and enhanced Akt activation. Compared with cells transfected with vector, ATO-induced apoptosis was decreased and G2/M phase cells were increased at the same concentration (P < 0.05). The PI3K/Akt inhibitor, LY294002, re-sensitized Cbl-b (DN) overexpressing cells to ATO and reversed G2/M arrest (P < 0.05). Taken together, these results suggest that Cbl-b potentiates the apoptotic action of ATO by inhibition of the PI3K/Akt pathway. |
publisher |
Associação Brasileira de Divulgação Científica |
publishDate |
2011 |
url |
http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000200004 |
work_keys_str_mv |
AT yingchunli e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT xiujuanqu e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT jingleiqu e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT yezhang e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT jingliu e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT yueeteng e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT xuejunhu e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT kezuohou e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway AT yunpengliu e3ubiquitinligasecblbpotentiatestheapoptoticactionofarsenictrioxidebyinhibitingthepi3kaktpathway |
_version_ |
1756391326475091968 |