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Elevation of cAMP Levels Inhibits Doxorubicin-Induced Apoptosis in Pre- B ALL NALM- 6 Cells Through Induction of BAD Phosphorylation and Inhibition of P53 Accumulation.

Fatemi A, Kazemi A, Kashiri M, Safa M - Int J Mol Cell Med (2015)

Bottom Line: Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone.Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents.However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology, School of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran.

ABSTRACT
Recognition of the molecular mechanisms of cAMP action against DNA damage-induced apoptosis can be useful to improve the efficacy of DNA damaging therapeutic agents. Considering the critical role of bcl-2-associated death promoter (BAD) and p53 proteins in DNA damage -induced apoptosis, the aim of this study was to assess the effect of cAMP-elevating agents on these proteins in doxorubicin-treated pre-B acute lymphoblastic leukemia (pre-B ALL) NALM-6 cells.The pre-B ALL cell line NALM-6 was cultured and treated with doxorubicin in combination with or without cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine (IBMX). Cell viability was measured by trypan blue staining and MTT assay. For evaluation of apoptosis, annexin-V staining by flow cytometry and caspase-3 activity assay were used. Protein expression of p53, BAD and phoshorylated BAD was detected by western blotting analysis.cAMP-increasing agents diminished the doxorubicin-mediated cytotoxicity in NALM-6 cells as indicated by the viability assays. Annexin-V apoptosis assay showed that the cAMP-elevating agents decreased doxorubicin-induced apoptosis. Moreover, doxorubicin-induced caspase-3 activity was attenuated in the presence of cAMP-increasing agents. Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone. Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents. However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents. Our study suggests that elevated cAMP levels inhibit doxorubicin-induced apoptosis in pre-B ALL cells through induction of BAD phosphorylation and abrogation of p53 accumulation.

No MeSH data available.


Related in: MedlinePlus

Effect of cAMP levels on total p53 protein expression upon DNA damage. NALM-6 cells were treated with forskolin and IBMX (FI). After 30 min, the pretreated cells were incubated with doxorubicin for 4 h and then protein expression was assessed using western blot analysis. Elevated cAMP decreased p53 expression induced by doxorubicin in NALM-6 cells
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Figure 5: Effect of cAMP levels on total p53 protein expression upon DNA damage. NALM-6 cells were treated with forskolin and IBMX (FI). After 30 min, the pretreated cells were incubated with doxorubicin for 4 h and then protein expression was assessed using western blot analysis. Elevated cAMP decreased p53 expression induced by doxorubicin in NALM-6 cells

Mentions: NALM-6 cells accumulate p53 protein after DNA damage induced by doxorubicin. To evaluate whether doxorubicin-induced accumulation of p53 is affected by cAMP signaling pathway, protein expression of p53 was assessed after exposure of NALM-6 cells with doxorubicin in the presence or absence of forskolin / IBMX. As shown in Fig. 5, elevated levels of cAMP reduced p53 accumulation.


Elevation of cAMP Levels Inhibits Doxorubicin-Induced Apoptosis in Pre- B ALL NALM- 6 Cells Through Induction of BAD Phosphorylation and Inhibition of P53 Accumulation.

Fatemi A, Kazemi A, Kashiri M, Safa M - Int J Mol Cell Med (2015)

Effect of cAMP levels on total p53 protein expression upon DNA damage. NALM-6 cells were treated with forskolin and IBMX (FI). After 30 min, the pretreated cells were incubated with doxorubicin for 4 h and then protein expression was assessed using western blot analysis. Elevated cAMP decreased p53 expression induced by doxorubicin in NALM-6 cells
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4499571&req=5

Figure 5: Effect of cAMP levels on total p53 protein expression upon DNA damage. NALM-6 cells were treated with forskolin and IBMX (FI). After 30 min, the pretreated cells were incubated with doxorubicin for 4 h and then protein expression was assessed using western blot analysis. Elevated cAMP decreased p53 expression induced by doxorubicin in NALM-6 cells
Mentions: NALM-6 cells accumulate p53 protein after DNA damage induced by doxorubicin. To evaluate whether doxorubicin-induced accumulation of p53 is affected by cAMP signaling pathway, protein expression of p53 was assessed after exposure of NALM-6 cells with doxorubicin in the presence or absence of forskolin / IBMX. As shown in Fig. 5, elevated levels of cAMP reduced p53 accumulation.

Bottom Line: Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone.Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents.However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology, School of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran.

ABSTRACT
Recognition of the molecular mechanisms of cAMP action against DNA damage-induced apoptosis can be useful to improve the efficacy of DNA damaging therapeutic agents. Considering the critical role of bcl-2-associated death promoter (BAD) and p53 proteins in DNA damage -induced apoptosis, the aim of this study was to assess the effect of cAMP-elevating agents on these proteins in doxorubicin-treated pre-B acute lymphoblastic leukemia (pre-B ALL) NALM-6 cells.The pre-B ALL cell line NALM-6 was cultured and treated with doxorubicin in combination with or without cAMP-elevating agents forskolin and 3-isobutyl-1-methylxanthine (IBMX). Cell viability was measured by trypan blue staining and MTT assay. For evaluation of apoptosis, annexin-V staining by flow cytometry and caspase-3 activity assay were used. Protein expression of p53, BAD and phoshorylated BAD was detected by western blotting analysis.cAMP-increasing agents diminished the doxorubicin-mediated cytotoxicity in NALM-6 cells as indicated by the viability assays. Annexin-V apoptosis assay showed that the cAMP-elevating agents decreased doxorubicin-induced apoptosis. Moreover, doxorubicin-induced caspase-3 activity was attenuated in the presence of cAMP-increasing agents. Western blot results revealed the reduced expression of p53 protein in cells treated with combination of cAMP-elevating agents and doxorubicin in contrast to cells treated with doxorubicin alone. Expression of total BAD protein was not affected by doxorubicin and cAMP-elevating agents. However, phosphorylation of BAD protein was induced in the presence of cAMP-elevating agents. Our study suggests that elevated cAMP levels inhibit doxorubicin-induced apoptosis in pre-B ALL cells through induction of BAD phosphorylation and abrogation of p53 accumulation.

No MeSH data available.


Related in: MedlinePlus