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The reversal effects of 3-bromopyruvate on multidrug resistance in vitro and in vivo derived from human breast MCF-7/ADR cells.

Wu L, Xu J, Yuan W, Wu B, Wang H, Liu G, Wang X, Du J, Cai S - PLoS ONE (2014)

Bottom Line: The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates) in cells was significantly increased.Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate.Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the intracellular level of ATP and HK-II bioactivity, the inhibition of ATPase activity, and the slight decrease in P-glycoprotein expression in MCF-7/ADR cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Pharmacology, College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China.

ABSTRACT

Purpose: P-glycoprotein mediated efflux is one of the main mechanisms for multidrug resistance in cancers, and 3-Bromopyruvate acts as a promising multidrug resistance reversal compound in our study. To test the ability of 3-Bromopyruvate to overcome P-glycoprotein-mediated multidrug resistance and to explore its mechanisms of multidrug resistance reversal in MCF-7/ADR cells, we evaluate the in vitro and in vivo modulatory activity of this compound.

Methods: The in vitro and in vivo activity was determined using the MTT assay and human breast cancer xenograft models. The gene and protein expression of P-glycoprotein were determined using real-time polymerase chain reaction and the Western blotting technique, respectively. ABCB-1 bioactivity was tested by fluorescence microscopy, multi-mode microplate reader, and flow cytometry. The intracellular levels of ATP, HK-II, and ATPase activity were based on an assay kit according to the manufacturer's instructions.

Results: 3-Bromopyruvate treatment led to marked decreases in the IC50 values of selected chemotherapeutic drugs [e.g., doxorubicin (283 folds), paclitaxel (85 folds), daunorubicin (201 folds), and epirubicin (171 folds)] in MCF-7/ADR cells. 3-Bromopyruvate was found also to potentiate significantly the antitumor activity of epirubicin against MCF-7/ADR xenografts. The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates) in cells was significantly increased. Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate. Moreover, the ATPase activity was significantly inhibited when 3-Bromopyruvate was applied.

Conclusion: We demonstrated that 3-Bromopyruvate can reverse P-glycoprotein-mediated efflux in MCF-7/ADR cells. Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the intracellular level of ATP and HK-II bioactivity, the inhibition of ATPase activity, and the slight decrease in P-glycoprotein expression in MCF-7/ADR cells.

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The changes of tumor weight by 3-BrPA on MCF/ADR xenograft model.a: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised MCF-7 tumor from different mice. b: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor from different groups. c:A representative picture of the excised MCF-7 tumor sizes from different groups is shown on the 21th day after implantation. d: A representative picture of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor sizes from different groups is shown on the 21th day after implantation. Each group represents the mean of determinations, and the bar represents SD. ***P<0.001 versus the control group; **P<0.01 versus the control group.
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pone-0112132-g008: The changes of tumor weight by 3-BrPA on MCF/ADR xenograft model.a: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised MCF-7 tumor from different mice. b: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor from different groups. c:A representative picture of the excised MCF-7 tumor sizes from different groups is shown on the 21th day after implantation. d: A representative picture of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor sizes from different groups is shown on the 21th day after implantation. Each group represents the mean of determinations, and the bar represents SD. ***P<0.001 versus the control group; **P<0.01 versus the control group.

Mentions: Treatment of 3-BrPA tumor-bearing nude mice with EPI (0.5 mg/kg, i.v.) or 3-BrPA (5 mg/kg, i.v.) alone had little or no effect on the growth rate of the tumors (Fig. 7b and Fig. 8). However, 3-BrPA plus EPI reduced the growth rate of the tumors significantly (Fig. 7b and Fig. 8). Remarkably, the regimen of the combination of EPI and 3-BrPA did not cause any deaths in the experimental process. There was no substantial or reproducible increase in body weight loss in animals treated with EPI plus 3-BrPA compared with the drug-alone groups (Fig. 7c and 7d). This suggests that this regimen did not result in increased toxic side effects. Therefore, the toxicity of co-administration of EPI and 3-BrPA was tolerable.


The reversal effects of 3-bromopyruvate on multidrug resistance in vitro and in vivo derived from human breast MCF-7/ADR cells.

Wu L, Xu J, Yuan W, Wu B, Wang H, Liu G, Wang X, Du J, Cai S - PLoS ONE (2014)

The changes of tumor weight by 3-BrPA on MCF/ADR xenograft model.a: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised MCF-7 tumor from different mice. b: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor from different groups. c:A representative picture of the excised MCF-7 tumor sizes from different groups is shown on the 21th day after implantation. d: A representative picture of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor sizes from different groups is shown on the 21th day after implantation. Each group represents the mean of determinations, and the bar represents SD. ***P<0.001 versus the control group; **P<0.01 versus the control group.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4221289&req=5

pone-0112132-g008: The changes of tumor weight by 3-BrPA on MCF/ADR xenograft model.a: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised MCF-7 tumor from different mice. b: The bar graph represents the mean of tumor weights (mice, n = 6) of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor from different groups. c:A representative picture of the excised MCF-7 tumor sizes from different groups is shown on the 21th day after implantation. d: A representative picture of the excised ABCB-1/P-gp overexpressing MCF-7/ADR tumor sizes from different groups is shown on the 21th day after implantation. Each group represents the mean of determinations, and the bar represents SD. ***P<0.001 versus the control group; **P<0.01 versus the control group.
Mentions: Treatment of 3-BrPA tumor-bearing nude mice with EPI (0.5 mg/kg, i.v.) or 3-BrPA (5 mg/kg, i.v.) alone had little or no effect on the growth rate of the tumors (Fig. 7b and Fig. 8). However, 3-BrPA plus EPI reduced the growth rate of the tumors significantly (Fig. 7b and Fig. 8). Remarkably, the regimen of the combination of EPI and 3-BrPA did not cause any deaths in the experimental process. There was no substantial or reproducible increase in body weight loss in animals treated with EPI plus 3-BrPA compared with the drug-alone groups (Fig. 7c and 7d). This suggests that this regimen did not result in increased toxic side effects. Therefore, the toxicity of co-administration of EPI and 3-BrPA was tolerable.

Bottom Line: The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates) in cells was significantly increased.Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate.Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the intracellular level of ATP and HK-II bioactivity, the inhibition of ATPase activity, and the slight decrease in P-glycoprotein expression in MCF-7/ADR cells.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical Pharmacology, College of Pharmacy, Jinan University, Guangzhou 510632, P. R. China.

ABSTRACT

Purpose: P-glycoprotein mediated efflux is one of the main mechanisms for multidrug resistance in cancers, and 3-Bromopyruvate acts as a promising multidrug resistance reversal compound in our study. To test the ability of 3-Bromopyruvate to overcome P-glycoprotein-mediated multidrug resistance and to explore its mechanisms of multidrug resistance reversal in MCF-7/ADR cells, we evaluate the in vitro and in vivo modulatory activity of this compound.

Methods: The in vitro and in vivo activity was determined using the MTT assay and human breast cancer xenograft models. The gene and protein expression of P-glycoprotein were determined using real-time polymerase chain reaction and the Western blotting technique, respectively. ABCB-1 bioactivity was tested by fluorescence microscopy, multi-mode microplate reader, and flow cytometry. The intracellular levels of ATP, HK-II, and ATPase activity were based on an assay kit according to the manufacturer's instructions.

Results: 3-Bromopyruvate treatment led to marked decreases in the IC50 values of selected chemotherapeutic drugs [e.g., doxorubicin (283 folds), paclitaxel (85 folds), daunorubicin (201 folds), and epirubicin (171 folds)] in MCF-7/ADR cells. 3-Bromopyruvate was found also to potentiate significantly the antitumor activity of epirubicin against MCF-7/ADR xenografts. The intracellular level of ATP decreased 44%, 46% in the presence of 12.5.25 µM 3-Bromopyruvate, whereas the accumulation of rhodamine 123 and epirubicin (two typical P-glycoprotein substrates) in cells was significantly increased. Furthermore, we found that the mRNA and the total protein level of P-glycoprotein were slightly altered by 3-Bromopyruvate. Moreover, the ATPase activity was significantly inhibited when 3-Bromopyruvate was applied.

Conclusion: We demonstrated that 3-Bromopyruvate can reverse P-glycoprotein-mediated efflux in MCF-7/ADR cells. Multidrug resistance reversal by 3-Bromopyruvate occurred through at least three approaches, namely, a decrease in the intracellular level of ATP and HK-II bioactivity, the inhibition of ATPase activity, and the slight decrease in P-glycoprotein expression in MCF-7/ADR cells.

Show MeSH
Related in: MedlinePlus