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The Proteasome Inhibitor Bortezomib Sensitizes AML with Myelomonocytic Differentiation to TRAIL Mediated Apoptosis.

Dijk Mv, Murphy E, Morrell R, Knapper S, O'Dwyer M, Samali A, Szegezdi E - Cancers (Basel) (2011)

Bottom Line: In this report we show that a combination of the proteasome inhibitor bortezomib and TRAIL is effective against AML cell lines, in particular, AML cell lines displaying myelomonocytic/monocytic phenotype (M4/M5 AML based on FAB classification), which account for 20-30% of AML cases.We show that the underlying mechanism of sensitization is at least in part due to bortezomib mediated downregulation of c-FLIP and XIAP, which is likely to be regulated by NF-κB.Blockage of NF-κB activation with BMS-345541 equally sensitized myelomonocytic AML cell lines and primary AML blasts to TRAIL.

View Article: PubMed Central - PubMed

Affiliation: Apoptosis Research Center, National University of Ireland, University Road, Galway, Ireland. eva.szegezdi@nuigalway.ie.

ABSTRACT
Acute myeloid leukemia (AML) is an aggressive stem cell malignancy that is difficult to treat. There are limitations to the current treatment regimes especially after disease relapse, and therefore new therapeutic agents are urgently required which can overcome drug resistance whilst avoiding unnecessary toxicity. Among newer targeted agents, both tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and proteasome inhibitors show particular promise. In this report we show that a combination of the proteasome inhibitor bortezomib and TRAIL is effective against AML cell lines, in particular, AML cell lines displaying myelomonocytic/monocytic phenotype (M4/M5 AML based on FAB classification), which account for 20-30% of AML cases. We show that the underlying mechanism of sensitization is at least in part due to bortezomib mediated downregulation of c-FLIP and XIAP, which is likely to be regulated by NF-κB. Blockage of NF-κB activation with BMS-345541 equally sensitized myelomonocytic AML cell lines and primary AML blasts to TRAIL.

No MeSH data available.


Related in: MedlinePlus

Bortezomib sensitizes ML-1, ML-2, OCI AML2, OCI AML3 and MOLM13 to TRAIL induced apoptosis. AML cells were pre-treated with a sublethal dose of bortezomib that induced 20% cell death (2 nM (KG-1), 4 nM (KG-1, ML-2), 5 nM (HL-60), 7 nM (ML-1), 8 nM (Kasumi, OCI AML2, MOLM13) or 10 nM (OCI AML3)) for 18 h followed by a 18 h (KG-1, Kasumi, OCI AML3, ML-2) or 24 h (HL-60, ML-1, OCI AML2, MOLM13) treatment with 5, 10, 25, 50, 100, 250, 500 or 1000 ng/mL TRAIL. Cell viability was measured by MTT assay; values are expressed as a percent of untreated cells and presented as mean ± S.E.M. (A) HL-60; (B) KG-1; (C) Kasumi; (D) OCI AML2; (E) OCI AML3; (F) MOLM13; (G) ML-2; (H) ML-1.
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f5-cancers-03-01329: Bortezomib sensitizes ML-1, ML-2, OCI AML2, OCI AML3 and MOLM13 to TRAIL induced apoptosis. AML cells were pre-treated with a sublethal dose of bortezomib that induced 20% cell death (2 nM (KG-1), 4 nM (KG-1, ML-2), 5 nM (HL-60), 7 nM (ML-1), 8 nM (Kasumi, OCI AML2, MOLM13) or 10 nM (OCI AML3)) for 18 h followed by a 18 h (KG-1, Kasumi, OCI AML3, ML-2) or 24 h (HL-60, ML-1, OCI AML2, MOLM13) treatment with 5, 10, 25, 50, 100, 250, 500 or 1000 ng/mL TRAIL. Cell viability was measured by MTT assay; values are expressed as a percent of untreated cells and presented as mean ± S.E.M. (A) HL-60; (B) KG-1; (C) Kasumi; (D) OCI AML2; (E) OCI AML3; (F) MOLM13; (G) ML-2; (H) ML-1.

Mentions: We next evaluated the effect of bortezomib-induced proteasome inhibition in combination with rhTRAIL-mediated death in the panel of AML cell lines. Cells were treated with a concentration of bortezomib that induced approximately 20% reduction in viability and was sufficient to inhibit the chymotrypsin-like activity of the proteasome. Pre-treatment of cells with bortezomib for 18 h followed by rhTRAIL treatment for a further 18 h or 24 h led to TRAIL sensitization in ML-1, ML-2, OCI AML2, OCI AML3 cells and MOLM13 (Figure 5D, 5E, 5F, 5G, 5H). Interestingly, all of these cell lines are of either myelomonocytic (M4) or monocytic (M5) differentiation. The synergistic action of the two agents was confirmed with a combination index (CI) <1 using the Chou-Talalay method (Table 1). Pretreatment with bortezomib did not sensitize HL-60, KG-1 and Kasumi to rhTRAIL-induced apoptosis (Figure 5A, 5B and 5C). Results were confirmed using Annexin V/PI assay (data not shown).


The Proteasome Inhibitor Bortezomib Sensitizes AML with Myelomonocytic Differentiation to TRAIL Mediated Apoptosis.

Dijk Mv, Murphy E, Morrell R, Knapper S, O'Dwyer M, Samali A, Szegezdi E - Cancers (Basel) (2011)

Bortezomib sensitizes ML-1, ML-2, OCI AML2, OCI AML3 and MOLM13 to TRAIL induced apoptosis. AML cells were pre-treated with a sublethal dose of bortezomib that induced 20% cell death (2 nM (KG-1), 4 nM (KG-1, ML-2), 5 nM (HL-60), 7 nM (ML-1), 8 nM (Kasumi, OCI AML2, MOLM13) or 10 nM (OCI AML3)) for 18 h followed by a 18 h (KG-1, Kasumi, OCI AML3, ML-2) or 24 h (HL-60, ML-1, OCI AML2, MOLM13) treatment with 5, 10, 25, 50, 100, 250, 500 or 1000 ng/mL TRAIL. Cell viability was measured by MTT assay; values are expressed as a percent of untreated cells and presented as mean ± S.E.M. (A) HL-60; (B) KG-1; (C) Kasumi; (D) OCI AML2; (E) OCI AML3; (F) MOLM13; (G) ML-2; (H) ML-1.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3756416&req=5

f5-cancers-03-01329: Bortezomib sensitizes ML-1, ML-2, OCI AML2, OCI AML3 and MOLM13 to TRAIL induced apoptosis. AML cells were pre-treated with a sublethal dose of bortezomib that induced 20% cell death (2 nM (KG-1), 4 nM (KG-1, ML-2), 5 nM (HL-60), 7 nM (ML-1), 8 nM (Kasumi, OCI AML2, MOLM13) or 10 nM (OCI AML3)) for 18 h followed by a 18 h (KG-1, Kasumi, OCI AML3, ML-2) or 24 h (HL-60, ML-1, OCI AML2, MOLM13) treatment with 5, 10, 25, 50, 100, 250, 500 or 1000 ng/mL TRAIL. Cell viability was measured by MTT assay; values are expressed as a percent of untreated cells and presented as mean ± S.E.M. (A) HL-60; (B) KG-1; (C) Kasumi; (D) OCI AML2; (E) OCI AML3; (F) MOLM13; (G) ML-2; (H) ML-1.
Mentions: We next evaluated the effect of bortezomib-induced proteasome inhibition in combination with rhTRAIL-mediated death in the panel of AML cell lines. Cells were treated with a concentration of bortezomib that induced approximately 20% reduction in viability and was sufficient to inhibit the chymotrypsin-like activity of the proteasome. Pre-treatment of cells with bortezomib for 18 h followed by rhTRAIL treatment for a further 18 h or 24 h led to TRAIL sensitization in ML-1, ML-2, OCI AML2, OCI AML3 cells and MOLM13 (Figure 5D, 5E, 5F, 5G, 5H). Interestingly, all of these cell lines are of either myelomonocytic (M4) or monocytic (M5) differentiation. The synergistic action of the two agents was confirmed with a combination index (CI) <1 using the Chou-Talalay method (Table 1). Pretreatment with bortezomib did not sensitize HL-60, KG-1 and Kasumi to rhTRAIL-induced apoptosis (Figure 5A, 5B and 5C). Results were confirmed using Annexin V/PI assay (data not shown).

Bottom Line: In this report we show that a combination of the proteasome inhibitor bortezomib and TRAIL is effective against AML cell lines, in particular, AML cell lines displaying myelomonocytic/monocytic phenotype (M4/M5 AML based on FAB classification), which account for 20-30% of AML cases.We show that the underlying mechanism of sensitization is at least in part due to bortezomib mediated downregulation of c-FLIP and XIAP, which is likely to be regulated by NF-κB.Blockage of NF-κB activation with BMS-345541 equally sensitized myelomonocytic AML cell lines and primary AML blasts to TRAIL.

View Article: PubMed Central - PubMed

Affiliation: Apoptosis Research Center, National University of Ireland, University Road, Galway, Ireland. eva.szegezdi@nuigalway.ie.

ABSTRACT
Acute myeloid leukemia (AML) is an aggressive stem cell malignancy that is difficult to treat. There are limitations to the current treatment regimes especially after disease relapse, and therefore new therapeutic agents are urgently required which can overcome drug resistance whilst avoiding unnecessary toxicity. Among newer targeted agents, both tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) and proteasome inhibitors show particular promise. In this report we show that a combination of the proteasome inhibitor bortezomib and TRAIL is effective against AML cell lines, in particular, AML cell lines displaying myelomonocytic/monocytic phenotype (M4/M5 AML based on FAB classification), which account for 20-30% of AML cases. We show that the underlying mechanism of sensitization is at least in part due to bortezomib mediated downregulation of c-FLIP and XIAP, which is likely to be regulated by NF-κB. Blockage of NF-κB activation with BMS-345541 equally sensitized myelomonocytic AML cell lines and primary AML blasts to TRAIL.

No MeSH data available.


Related in: MedlinePlus