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AKT signaling as a novel factor associated with in vitro resistance of human AML to gemtuzumab ozogamicin.

Rosen DB, Harrington KH, Cordeiro JA, Leung LY, Putta S, Lacayo N, Laszlo GS, Gudgeon CJ, Hogge DE, Hawtin RE, Cesano A, Walter RB - PLoS ONE (2013)

Bottom Line: Supporting this notion, we found activated PI3K/AKT signaling to be associated with GO resistance in vitro in primary AML cells.Consistently, the investigational AKT inhibitor MK-2206 significantly sensitized various human AML cells to GO or free calicheamicin-γ(1) with particularly pronounced effects in otherwise GO or free calicheamicin-γ(1)-resistant cells.The identification of AKT signaling as being associated with GO resistance in vitro may provide a novel approach to improve the in vivo efficacy of GO/calicheamicin-γ(1) and, by extrapolation, other DNA damage-based therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Nodality Inc., South San Francisco, California, United States of America.

ABSTRACT
Gemtuzumab ozogamicin (GO), an immunoconjugate between an anti-CD33 antibody and a calicheamicin-γ(1) derivative, induces remissions and improves survival in a subset of patients with acute myeloid leukemia (AML). As the mechanisms underlying GO and calicheamicin-γ(1) resistance are incompletely understood, we herein used flow cytometry-based single cell network profiling (SCNP) assays to study cellular responses of primary human AML cells to GO. Our data indicate that the extent of DNA damage is quantitatively impacted by CD33 expression and drug efflux activity. However, although DNA damage is required for GO-induced cytotoxicity, it is not sufficient for effective cell kill, suggesting that downstream anti-apoptotic pathways may function as relevant resistance mechanisms. Supporting this notion, we found activated PI3K/AKT signaling to be associated with GO resistance in vitro in primary AML cells. Consistently, the investigational AKT inhibitor MK-2206 significantly sensitized various human AML cells to GO or free calicheamicin-γ(1) with particularly pronounced effects in otherwise GO or free calicheamicin-γ(1)-resistant cells. Likewise, MK-2206 also sensitized primary AML cells to calicheamicin-γ(1). Together, our findings illustrate the capacity of SCNP assays to discover chemotherapy-related biological pathways and signaling networks relevant to GO-induced genotoxic stress. The identification of AKT signaling as being associated with GO resistance in vitro may provide a novel approach to improve the in vivo efficacy of GO/calicheamicin-γ(1) and, by extrapolation, other DNA damage-based therapeutics.

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Related in: MedlinePlus

Functional characterization of GO-induced cytotoxicity in CD33+ cells.Scheme depicts the presumed mechanism of action of GO in CD33+ AML cells [5], [11]. Experimentally measured components in our studies are shown in red: CD33 expression levels; drug efflux pump activity; γH2AX (extent of DNA damage); survival signaling pathways (PI3K/AKT, MEK/ERK, and JAK/STAT pathway); and cleaved PARP and cell membrane integrity (apoptosis/cell death).
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pone-0053518-g001: Functional characterization of GO-induced cytotoxicity in CD33+ cells.Scheme depicts the presumed mechanism of action of GO in CD33+ AML cells [5], [11]. Experimentally measured components in our studies are shown in red: CD33 expression levels; drug efflux pump activity; γH2AX (extent of DNA damage); survival signaling pathways (PI3K/AKT, MEK/ERK, and JAK/STAT pathway); and cleaved PARP and cell membrane integrity (apoptosis/cell death).

Mentions: With GO, the antibody primarily facilitates cellular uptake of the calicheamicin-γ1 derivative, which is then released intracellularly and causes single- and double-stranded DNA damage (Figure 1) [5]. Conceptually, the amount of intracellular, active calicheamicin is affected by cellular uptake, toxin release and activation, as well as drug inactivation/metabolism or extrusion. Indeed, correlative and in vitro studies have shown that drug efflux mediated by P-glycoprotein (Pgp, MDR1) and, to a lesser degree, multidrug resistance protein (MRP1), mediate resistance to GO [5], [11]. Similarly consistently, experimental studies revealed a striking, quantitative relationship between CD33 expression/uptake and GO efficacy in engineered AML cell lines [12], [13].


AKT signaling as a novel factor associated with in vitro resistance of human AML to gemtuzumab ozogamicin.

Rosen DB, Harrington KH, Cordeiro JA, Leung LY, Putta S, Lacayo N, Laszlo GS, Gudgeon CJ, Hogge DE, Hawtin RE, Cesano A, Walter RB - PLoS ONE (2013)

Functional characterization of GO-induced cytotoxicity in CD33+ cells.Scheme depicts the presumed mechanism of action of GO in CD33+ AML cells [5], [11]. Experimentally measured components in our studies are shown in red: CD33 expression levels; drug efflux pump activity; γH2AX (extent of DNA damage); survival signaling pathways (PI3K/AKT, MEK/ERK, and JAK/STAT pathway); and cleaved PARP and cell membrane integrity (apoptosis/cell death).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539972&req=5

pone-0053518-g001: Functional characterization of GO-induced cytotoxicity in CD33+ cells.Scheme depicts the presumed mechanism of action of GO in CD33+ AML cells [5], [11]. Experimentally measured components in our studies are shown in red: CD33 expression levels; drug efflux pump activity; γH2AX (extent of DNA damage); survival signaling pathways (PI3K/AKT, MEK/ERK, and JAK/STAT pathway); and cleaved PARP and cell membrane integrity (apoptosis/cell death).
Mentions: With GO, the antibody primarily facilitates cellular uptake of the calicheamicin-γ1 derivative, which is then released intracellularly and causes single- and double-stranded DNA damage (Figure 1) [5]. Conceptually, the amount of intracellular, active calicheamicin is affected by cellular uptake, toxin release and activation, as well as drug inactivation/metabolism or extrusion. Indeed, correlative and in vitro studies have shown that drug efflux mediated by P-glycoprotein (Pgp, MDR1) and, to a lesser degree, multidrug resistance protein (MRP1), mediate resistance to GO [5], [11]. Similarly consistently, experimental studies revealed a striking, quantitative relationship between CD33 expression/uptake and GO efficacy in engineered AML cell lines [12], [13].

Bottom Line: Supporting this notion, we found activated PI3K/AKT signaling to be associated with GO resistance in vitro in primary AML cells.Consistently, the investigational AKT inhibitor MK-2206 significantly sensitized various human AML cells to GO or free calicheamicin-γ(1) with particularly pronounced effects in otherwise GO or free calicheamicin-γ(1)-resistant cells.The identification of AKT signaling as being associated with GO resistance in vitro may provide a novel approach to improve the in vivo efficacy of GO/calicheamicin-γ(1) and, by extrapolation, other DNA damage-based therapeutics.

View Article: PubMed Central - PubMed

Affiliation: Nodality Inc., South San Francisco, California, United States of America.

ABSTRACT
Gemtuzumab ozogamicin (GO), an immunoconjugate between an anti-CD33 antibody and a calicheamicin-γ(1) derivative, induces remissions and improves survival in a subset of patients with acute myeloid leukemia (AML). As the mechanisms underlying GO and calicheamicin-γ(1) resistance are incompletely understood, we herein used flow cytometry-based single cell network profiling (SCNP) assays to study cellular responses of primary human AML cells to GO. Our data indicate that the extent of DNA damage is quantitatively impacted by CD33 expression and drug efflux activity. However, although DNA damage is required for GO-induced cytotoxicity, it is not sufficient for effective cell kill, suggesting that downstream anti-apoptotic pathways may function as relevant resistance mechanisms. Supporting this notion, we found activated PI3K/AKT signaling to be associated with GO resistance in vitro in primary AML cells. Consistently, the investigational AKT inhibitor MK-2206 significantly sensitized various human AML cells to GO or free calicheamicin-γ(1) with particularly pronounced effects in otherwise GO or free calicheamicin-γ(1)-resistant cells. Likewise, MK-2206 also sensitized primary AML cells to calicheamicin-γ(1). Together, our findings illustrate the capacity of SCNP assays to discover chemotherapy-related biological pathways and signaling networks relevant to GO-induced genotoxic stress. The identification of AKT signaling as being associated with GO resistance in vitro may provide a novel approach to improve the in vivo efficacy of GO/calicheamicin-γ(1) and, by extrapolation, other DNA damage-based therapeutics.

Show MeSH
Related in: MedlinePlus