Article

[Role of WAVE1 in drug resistance of K562/A02 leukemia cells].

Department of Pediatrics, Xiangya Hospital, Central South University, Changsha 410008, China.
Zhonghua xue ye xue za zhi = Zhonghua xueyexue zazhi 07/2007; 28(6):379-82.
Source: PubMed

ABSTRACT To investigate if WAVE1 is involved in mult drug-resistance (MDR) of human leukemia cell line K562/A02.
The level of WAVE1 in K562 and K562/A02 cells was assayed by Western blot and RT-PCR; K562 cells and K562/A02 cells were transient transfected with pEFBOS-WAVE1 reconstructed plasmid or specifically siRNA to WAVE1. 50% inhibition concentration (IC50) of doxorubicin on K562/A02 was determined by WST-8 assay. Hoechst33258 staining was used to examine cell morphological changes and to calculate percentage of apoptotic nuclei. The mRNA level of mdrl was assayed by RT-PCR. The Bcl-2 protein was assayed by Western blot.
1. The WAVE1 expression at mRNA and protein level in K562/A02 cells was increased by about 70% and 63% respectively as compared with that in K562 cells. 2. Overexpression of WAVE1 in K562 cells by transient transfection significantly increased the resistance to doxorubicin, and increased IC50 from (0.05 +/- 0.00) microg/ml to (2.99 +/- 0.12) microg/ml, and at 1 microg/ml or 5 microg/ml of doxorubicin treatment, cell apoptotic nuclei rate was decreased by 30% or 35% respectively. 3. Suppression of WAVE1 in K562/A02 cells by siRNA resulted in a reversal of MDR to doxorubicin, and decreased IC50 from (4.29 +/- 0.15) microg/ml to (1.85 +/- 0.07) microg/ml, and at 1 microg/ml or 5 microg/ml of doxorubicin treatment, cell apoptotic nuclei rate was increased by 24% or 21% respectively. 4. Overexpression of WAVE1 in K562 cells significantly increased the mdrl mRNA and the Bcl-2 protein, and suppression of WAVE1 in K562/A02 cells by siRNA decreased the mRNA and the protein.
WAVE1 involves in the MDR mechanisms in K562/A02 leukemia cells through regulation the level of mdrl and Bcl-2.

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  • Article: WAVE1 regulates Bcl-2 localization and phosphorylation in leukemia cells.
    R Kang, D Tang, Y Yu, Z Wang, T Hu, H Wang, L Cao
    [show abstract] [hide abstract]
    ABSTRACT: Bcl-2 proteins are over-expressed in many tumors and are critically important for cell survival. Their anti-apoptotic activities are determined by intracellular localization and post-translational modifications (such as phosphorylation). Here, we showed that WAVE1, a member of the Wiskott-Aldrich syndrome protein family, was over-expressed in blood cancer cell lines, and functioned as a negative regulator of apoptosis. Further enhanced expression of WAVE1 by gene transfection rendered leukemia cells more resistant to anti-cancer drug-induced apoptosis; whereas suppression of WAVE1 expression by RNA interference restored leukemia cells' sensitivity to anti-drug-induced apoptosis. WAVE1 was found to be associated with mitochondrial Bcl-2, and its depletion led to mitochondrial release of Bcl-2, and phosphorylation of ASK1/JNK and Bcl-2. Furthermore, depletion of WAVE1 expression increased anti-cancer drug-induced production of reactive oxygen species in leukemia cells. Taken together, these results suggest WAVE1 as a novel regulator of apoptosis, and potential drug target for therapeutic intervention of leukemia.
    Leukemia: official journal of the Leukemia Society of America, Leukemia Research Fund, U.K 11/2009; 24(1):177-86. · 8.30 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

Keywords

5 microg/ml
 
50% inhibition concentration
 
apoptotic nuclei
 
Bcl-2 protein
 
calculate percentage
 
cell apoptotic nuclei rate
 
cell morphological changes
 
Hoechst33258 staining
 
human leukemia cell line K562/A02
 
MDR mechanisms
 
mdrl mRNA
 
mRNA level
 
mult drug-resistance
 
Overexpression
 
pEFBOS-WAVE1 reconstructed plasmid
 
protein level
 
transient transfection
 
WAVE1 expression
 
Western blot
 
WST-8 assay
 

Rui Kang