TY - JOUR
T1 - Amiloride modulates alternative splicing in leukemic cells and resensitizes Bcr-AblT315I mutant cells to imatinib
AU - Chang, Wen Hsin
AU - Liu, Ta Chih
AU - Yang, Wen Kuang
AU - Lee, Chien Chih
AU - Lin, Yi Hsiung
AU - Chen, Tsai Yun
AU - Chang, Jan Gowth
PY - 2011/1/15
Y1 - 2011/1/15
N2 - The antihypertensive drug amiloride is being considered as a tactic to improve cancer therapy including that for chronic myelogenous leukemia. In this study, we show that amiloride modulates the alternative splicing of various cancer genes, including Bcl-x, HIPK3, and BCR/ABL, and that this effect is not mainly related to pH alteration, which is a known effect of the drug. Splice modulation involved various splicing factors, with the phosphorylation state of serine-arginine-rich (SR) proteins also altered during the splicing process. Pretreatment with okadaic acid to inhibit protein phosphatase PP1 reversed partially the phosphorylation levels of SR proteins and also the amiloride-modulated yields of Bcl-xs and HIPK3 U(-) isoforms. Genome-wide detection of alternative splicing further revealed that many other apoptotic genes were regulated by amiloride, including APAF-1, CRK, and SURVIVIN. Various proteins of the Bcl-2 family and MAPK kinases were found to be involved in amiloride-induced apoptosis. Moreover, the effect of amiloride on mRNA levels of Bcl-x was demonstrated to translate to the protein levels. Cotreatment of K562 and BaF3/Bcr-AblT315I cells with amiloride and imatinib induced more loss of cell viability than either agent alone. Our findings suggest that amiloride may offer a potential treatment option for chronic myelogenous leukemia either alone or in combination with imatinib.
AB - The antihypertensive drug amiloride is being considered as a tactic to improve cancer therapy including that for chronic myelogenous leukemia. In this study, we show that amiloride modulates the alternative splicing of various cancer genes, including Bcl-x, HIPK3, and BCR/ABL, and that this effect is not mainly related to pH alteration, which is a known effect of the drug. Splice modulation involved various splicing factors, with the phosphorylation state of serine-arginine-rich (SR) proteins also altered during the splicing process. Pretreatment with okadaic acid to inhibit protein phosphatase PP1 reversed partially the phosphorylation levels of SR proteins and also the amiloride-modulated yields of Bcl-xs and HIPK3 U(-) isoforms. Genome-wide detection of alternative splicing further revealed that many other apoptotic genes were regulated by amiloride, including APAF-1, CRK, and SURVIVIN. Various proteins of the Bcl-2 family and MAPK kinases were found to be involved in amiloride-induced apoptosis. Moreover, the effect of amiloride on mRNA levels of Bcl-x was demonstrated to translate to the protein levels. Cotreatment of K562 and BaF3/Bcr-AblT315I cells with amiloride and imatinib induced more loss of cell viability than either agent alone. Our findings suggest that amiloride may offer a potential treatment option for chronic myelogenous leukemia either alone or in combination with imatinib.
UR - http://www.scopus.com/inward/record.url?scp=78751562185&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=78751562185&partnerID=8YFLogxK
U2 - 10.1158/0008-5472.CAN-10-1037
DO - 10.1158/0008-5472.CAN-10-1037
M3 - Article
C2 - 21224352
AN - SCOPUS:78751562185
VL - 71
SP - 383
EP - 392
JO - Cancer Research
JF - Cancer Research
SN - 0008-5472
IS - 2
ER -