Stress-induced in vitro apoptosis of native human acute myelogenous leukemia (AML) cells shows a wide variation between patients and is associated with low BCL-2:Bax ratio and low levels of heat shock protein 70 and 90

Ryningen, Anita; Ersvær, Elisabeth; Øyan, Anne Margrete; Kalland, Karl‐Henning; Vintermyr, Olav Karsten; Gjertsen, Bjørn Tore; Bruserud, Øystein

doi:10.1016/j.leukres.2006.02.014

Cited by 53 publications

(80 citation statements)

References 22 publications

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“…Finally, the expression of Annexin v and calreticulin was analysed separately for the dead and viable AMl cell subsets. As expected from previous studies we could identify distinct Annexin v-positive and -negative cell subpopulations (27). calreticulin-positive cells could then be identified as separate populations among viable or dead cell subsets.…”

Section: Immunogenic Apoptosis In Human Acute Myeloid Leukemia (Aml):supporting

confidence: 81%

“…We used an experimental in vitro model with culture of primary human AMl cells in serum-free medium for analysis of apoptosis; this model has been characterized in detail previously (23,27). cytarabine was then tested at three different concentrations that were selected based on their effects on cytokine-dependent (Flt3l+scF+gM-csF) AMl cell proliferation.…”

Section: Standardization Of the Experimental In Vitro Modelsmentioning

confidence: 99%

“…primary AMl cells will undergo spontaneous apoptosis during in vitro culture; the degree of apoptosis then shows a wide variation between patients (27). In all our studies we used cryopreserved cells that showed a high viability generally exceeding 80% at initiation of culture.…”

Section: Standardization Of the Experimental In Vitro Modelsmentioning

confidence: 99%

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Immunogenic apoptosis in human acute myeloid leukemia (AML): primary human AML cells expose calreticulin and release heat shock protein (HSP) 70 and HSP90 during apoptosis

Fredly

Ersvær²,

Gjertsen³

et al. 2011

Oncol Rep

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Abstract. several previous studies have demonstrated that both conventional cytotoxic drugs as well as targeted therapeutics can induce apoptosis in primary human acute myelogenous leukemia (AMl) cells. However, the apoptotic phenotype of dying AMl cells has been less extensively characterized. even though specific antileukemic immune reactivity is important in AMl, especially for allotransplanted patients, it has not been investigated whether dying primary human AMl cells show phenotypic characteristics consistent with immunogenic apoptosis [calreticulin exposure, heat shock protein (Hsp) release]. We therefore investigated whether in vitro cultured primary human acute myeloid leukemia (AMl) cells show calreticulin exposure and Hsp70/Hsp90 release during spontaneous (stress-induced) apoptosis when cultured in medium alone and when cultured in the presence of antileukemic drugs. Both surface exposure of calreticulin and release of Hsp70 and Hsp90 was detected but showed a wide variation between patients. this variation was also maintained when the AMl cells were cultured in the presence of cytotoxic drugs (cytarabine, daunorubicin, mitomycin), all-trans retinoic acid (AtrA) and valproic acid. Finally, AMl cells collected during in vivo AtrA therapy showed increased calreticulin exposure during spontaneous in vitro apoptosis, suggesting that in vivo pharmacotherapy can modulate the apoptotic phenotype. to conclude, apoptotic AMl cells can show phenotypic characteristics consistent with immunogenic apoptosis, but there is a wide variation between patients and the level of calreticulin exposure/Hsp release seems to depend on individual patient characteristics rather than the apoptosisinducing agent.

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Section: Immunogenic Apoptosis In Human Acute Myeloid Leukemia (Aml):supporting

confidence: 81%

Section: Standardization Of the Experimental In Vitro Modelsmentioning

confidence: 99%

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Immunogenic apoptosis in human acute myeloid leukemia (AML): primary human AML cells expose calreticulin and release heat shock protein (HSP) 70 and HSP90 during apoptosis

Fredly

Ersvær²,

Gjertsen³

et al. 2011

Oncol Rep

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“…7 For this study, we measured several properties of p53 in primary AML cells, including TP53 gene sequence, per-cell abundance of p53 protein, and p53 phosphorylation at 5 residues. 8 Following DNA damage and cell stresses, p53 protein is rapidly phosphorylated at several residues, 9 including those we measured here (serines 15,20,37,46, and 392). Phosphorylation of p53 is thought to regulate p53 localization, conformation, and activity, 10 but the precise contribution of each phosphorylation site is controversial.…”

Section: Introductionmentioning

confidence: 71%

“…34 In contrast, in AML the relation between in vitro chemotherapy response, prognosis, and molecular features is less clear. 35,36 Our own experiences studying in vitro spontaneous and drug-induced apoptosis in primary AML cells, including patients with various Flt3 mutational status, have so far not convinced us that chemotherapy response reflects important prognostic features (data not shown, Bruserud et al, 21 and Ryningen et al 37 ). These results indicate that killing of AML cells in vitro (over a period of several hours) will likely be a less useful measurement than their immediate signaling biology, including basal phosphorylation and responses to stimulation (ie, a signaling profile including p53 phosphorylation).…”

Section: Discussionmentioning

confidence: 99%

Flt3 Y591 duplication and Bcl-2 overexpression are detected in acute myeloid leukemia cells with high levels of phosphorylated wild-type p53

Irish

Ånensen

Hovland

et al. 2006

Blood

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Loss or mutation of the TP53 tumor suppressor gene is not commonly observed in acute myeloid leukemia (AML), suggesting that there is an alternate route for cell transformation. We investigated the hypothesis that previously observed Bcl-2 family member overexpression suppresses wild-type p53 activity in AML. We demonstrate that wild-type p53 protein is expressed in primary leukemic blasts from patients with de novo AML using 2-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and phospho-specific flow cytometry. We found that p53 was heterogeneously expressed and phosphorylated in AML patient samples and could accumulate following DNA damage. Overexpression of antiapoptosis protein Bcl-2 in AML cells was directly correlated with p53 expression and phosphorylation on serine residues 15, 46, and 392. Within those patients with the highest levels of Bcl-2 expression, we identified a mutation in FLT3 that duplicated phosphorylation site Y591. The presence of this mutation correlated with greater than normal IntroductionWe have previously reported that signaling profiles of acute myeloid leukemia (AML) cells identify patients with a poor response to course one of chemotherapy. 1 In that study we showed that mutation of fms-like tyrosine kinase 3 (Flt3) was associated with increased activity of signal transduction and activator of transcription (STAT) family members Stat5 and Stat3, but we did not explore how this signaling might contribute to the observed therapy resistance. Here we examine the connection between a target of altered Stat5 signaling in AML-the Bcl-2 protein-and the suppression of normal apoptotic responses to DNA damage in leukemia cells. Evasion of apoptosis contributes to the formation and continued survival of cancer cells 2 and insight into signaling mechanisms that suppress apoptosis in AML cells could be used to improve the efficacy of existing therapies. 3 AML is particularly relevant to the study of suppressed apoptotic pathways in cancer because p53, a central driver of apoptosis and guardian of genomic integrity, is not generally lost or mutated in this disease. 4,5 p53 is a sequence-specific transcription factor that can halt progression through the cell cycle or initiate apoptosis. 6 Furthermore, p53 is a key tumor suppressor protein often lost or mutated in human cancers; however, TP53 has been reported to be mutant in only 7% of AML cases. 4 Subsequent research has also shown that downstream p53 effector genes, such as p21, are rarely lost in AML and that wild-type p53 protein is expressed in newly established AML derived cell lines. 7 For this study, we measured several properties of p53 in primary AML cells, including TP53 gene sequence, per-cell abundance of p53 protein, and p53 phosphorylation at 5 residues. 8 Following DNA damage and cell stresses, p53 protein is rapidly phosphorylated at several residues, 9 including those we measured here (serines 15, 20, 37, 46, and 392). Phosphorylation of p53 is thought to regulate p53 localization, conformation, and activity, 10 but t...

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Short-term exercise provides left ventricular myocardial protection against intermittent hypoxia-induced apoptosis in rats

et al. 2011

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We investigated whether exercise provides beneficial effects to attenuate intermittent hypoxia (IH)-induced myocardial apoptosis. Male Sprague-Dawley rats were randomly assigned to four groups: control (CON), IH, exercise (EXE) or IH interspersed with EXE (IHEXE). IH rats were exposed to repetitive hypoxia-reoxygenation cycles (30 s of 5% O(2); 45 s of 21% O(2), 6 h day(-1)) during the light phase (1000-1600 h) for 12 consecutive days. EXE rats were habituated to treadmill running for 5 days, permitted 2 days of rest, followed by 5 exercise bouts (30 m min(-1) for 60 min on a 2% grade) on consecutive days during the dark phase (2000-2200 h). IHEXE rats were exposed to IH during the light phase interspersed with exercise programs during the dark phase on the same day. Apoptosis levels, cytochrome c (Cyt-c), cleaved caspase-3, oxidative stress and antioxidant capacity were determined in the left ventricular (LV) myocardium. IH rats showed higher myocardial levels of the apoptotic index, mitochondria-released Cyt-c, cleaved caspase-3 and oxidative stress and lower catalase activity levels than CON rats (p < 0.05, for all). These changes were not observed in EXE rats (p > 0.05, for all) except that catalase activity increased (p < 0.05). IHEXE rats showed lower myocardial levels of apoptotic index, mitochondria-released Cyt-c, cleaved caspase-3 and oxidative stress and higher catalase activity levels (p < 0.05, for all) than IH rats. We conclude that short-term exercise provides potent cardioprotective effects by attenuating IH-induced myocardial apoptosis.

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Stress-induced in vitro apoptosis of native human acute myelogenous leukemia (AML) cells shows a wide variation between patients and is associated with low BCL-2:Bax ratio and low levels of heat shock protein 70 and 90

Cited by 53 publications

References 22 publications

Immunogenic apoptosis in human acute myeloid leukemia (AML): primary human AML cells expose calreticulin and release heat shock protein (HSP) 70 and HSP90 during apoptosis

Immunogenic apoptosis in human acute myeloid leukemia (AML): primary human AML cells expose calreticulin and release heat shock protein (HSP) 70 and HSP90 during apoptosis

Flt3 Y591 duplication and Bcl-2 overexpression are detected in acute myeloid leukemia cells with high levels of phosphorylated wild-type p53

Short-term exercise provides left ventricular myocardial protection against intermittent hypoxia-induced apoptosis in rats

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