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Lipid raft-mediated Akt signaling as a therapeutic target in mantle cell lymphoma.

Reis-Sobreiro M, Roué G, Moros A, Gajate C, de la Iglesia-Vicente J, Colomer D, Mollinedo F - Blood Cancer J (2013)

Bottom Line: The antitumor lipids (ATLs) edelfosine and perifosine target rafts, and we found that ATLs exerted in vitro and in vivo antitumor activity against MCL cells by displacing Akt as well as key regulatory kinases p-PDK1 (phosphatidylinositol-dependent protein kinase 1), PI3K and mTOR (mammalian TOR) from lipid rafts.Microenvironmental stimuli, such as CD40 ligation or stromal cell contact, did not prevent ATL-induced apoptosis in MCL cell lines and patient-derived cells.These results highlight the role of raft-mediated PI3K/Akt signaling in MCL cell survival and chemotherapy, thus becoming a new target for MCL treatment.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.

ABSTRACT
Recent evidence shows that lipid raft membrane domains modulate both cell survival and death. Here, we have found that the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway is present in the lipid rafts of mantle cell lymphoma (MCL) cells, and this location seems to be critical for full activation and MCL cell survival. The antitumor lipids (ATLs) edelfosine and perifosine target rafts, and we found that ATLs exerted in vitro and in vivo antitumor activity against MCL cells by displacing Akt as well as key regulatory kinases p-PDK1 (phosphatidylinositol-dependent protein kinase 1), PI3K and mTOR (mammalian TOR) from lipid rafts. This raft reorganization led to Akt dephosphorylation, while proapoptotic Fas/CD95 death receptor was recruited into rafts. Raft integrity was critical for Ser473 Akt phosphorylation. ATL-induced apoptosis appeared to correlate with the basal Akt phosphorylation status in MCL cell lines and primary cultures, and could be potentiated by the PI3K inhibitor wortmannin, or inhibited by the Akt activator pervanadate. Classical Akt inhibitors induced apoptosis in MCL cells. Microenvironmental stimuli, such as CD40 ligation or stromal cell contact, did not prevent ATL-induced apoptosis in MCL cell lines and patient-derived cells. These results highlight the role of raft-mediated PI3K/Akt signaling in MCL cell survival and chemotherapy, thus becoming a new target for MCL treatment.

No MeSH data available.


Related in: MedlinePlus

In vivo anti-MCL activity of edelfosine and perifosine, and effect of ATLs on MCL patient-derived cells. (a) CB17-severe combined immunodeficient mice were inoculated subcutaneously with 107 Z-138 cells, and once palpable tumors were detected, mice were orally treated with vehicle (control), 30 mg/kg edelfosine (EDLF) and 26.45 mg/kg perifosine (PRIF) for 3 weeks. Tumor size was recorded at the indicated times during drug treatment. (b) After completion of the in vivo assay, control mice and animals treated with edelfosine (EDLF) or perifosine (PRIF) were killed, and tumors were isolated and measured (weight and volume). Data in (a) and (b) are shown as mean values±s.d. (n=7). Asterisks indicate significant differences with respect to drug-free control values, at *P<0.05 and **P<0.01. (c) A notable reduction in tumor size was observed after edelfosine or perifosine treatment. (d) Isolated primary tumor MCL cells from nine patients were treated with 10 μℳ perifosine or edelfosine for 24 h. Non-apoptotic cells were quantified as Annexin V-negative cells by flow cytometry, as described in Materials and methods. Untreated controls were run in parallel, and data are represented as percentage of cell viability (means of two experiments) with respect to each untreated control. (e) MCL cells derived from patient no. 3, showing high-sensitivity to ATLs, and from patient no. 8, showing low sensitivity to ATLs, were incubated without (control, C) or with 10 μℳ perifosine (PRIF) or edelfosine (EDLF) for 6 h, and then analyzed by immunoblotting for p-Akt (Ser473) and Akt.
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fig6: In vivo anti-MCL activity of edelfosine and perifosine, and effect of ATLs on MCL patient-derived cells. (a) CB17-severe combined immunodeficient mice were inoculated subcutaneously with 107 Z-138 cells, and once palpable tumors were detected, mice were orally treated with vehicle (control), 30 mg/kg edelfosine (EDLF) and 26.45 mg/kg perifosine (PRIF) for 3 weeks. Tumor size was recorded at the indicated times during drug treatment. (b) After completion of the in vivo assay, control mice and animals treated with edelfosine (EDLF) or perifosine (PRIF) were killed, and tumors were isolated and measured (weight and volume). Data in (a) and (b) are shown as mean values±s.d. (n=7). Asterisks indicate significant differences with respect to drug-free control values, at *P<0.05 and **P<0.01. (c) A notable reduction in tumor size was observed after edelfosine or perifosine treatment. (d) Isolated primary tumor MCL cells from nine patients were treated with 10 μℳ perifosine or edelfosine for 24 h. Non-apoptotic cells were quantified as Annexin V-negative cells by flow cytometry, as described in Materials and methods. Untreated controls were run in parallel, and data are represented as percentage of cell viability (means of two experiments) with respect to each untreated control. (e) MCL cells derived from patient no. 3, showing high-sensitivity to ATLs, and from patient no. 8, showing low sensitivity to ATLs, were incubated without (control, C) or with 10 μℳ perifosine (PRIF) or edelfosine (EDLF) for 6 h, and then analyzed by immunoblotting for p-Akt (Ser473) and Akt.

Mentions: By using a xenograft MCL-bearing CB17-severe combined immunodeficient mouse model, we found that daily oral treatment for 3 weeks with ATLs (30 mg/kg edelfosine, molecular mass, 523.70 g/mol; 26.45 mg/kg perifosine, molecular mass, 461.67 g/mol) inhibited the growth of MCL cells. Serial caliper measurements were made to determine tumor growth, and showed a significant anti-MCL activity for both ATLs (Figure 6a). A comparison of tumors, isolated from drug-free control and ATL-treated MCL-bearing mice, at the end of treatment rendered a dramatic reduction of tumor weight and volume in mice treated with edelfosine or perifosine (Figures 6b and c). These results highlight the effectiveness of both edelfosine and perifosine in treating MCL in mice. No significant differences in mean body weight were observed between drug-treated and control animals during the in vivo assay (3–7% of body weight loss in the treated groups versus control groups), suggesting a low toxicity exerted by these two ATLs. This observation is in agreement with a previous report showing lack of significant toxicity of edelfosine in a rat model.48


Lipid raft-mediated Akt signaling as a therapeutic target in mantle cell lymphoma.

Reis-Sobreiro M, Roué G, Moros A, Gajate C, de la Iglesia-Vicente J, Colomer D, Mollinedo F - Blood Cancer J (2013)

In vivo anti-MCL activity of edelfosine and perifosine, and effect of ATLs on MCL patient-derived cells. (a) CB17-severe combined immunodeficient mice were inoculated subcutaneously with 107 Z-138 cells, and once palpable tumors were detected, mice were orally treated with vehicle (control), 30 mg/kg edelfosine (EDLF) and 26.45 mg/kg perifosine (PRIF) for 3 weeks. Tumor size was recorded at the indicated times during drug treatment. (b) After completion of the in vivo assay, control mice and animals treated with edelfosine (EDLF) or perifosine (PRIF) were killed, and tumors were isolated and measured (weight and volume). Data in (a) and (b) are shown as mean values±s.d. (n=7). Asterisks indicate significant differences with respect to drug-free control values, at *P<0.05 and **P<0.01. (c) A notable reduction in tumor size was observed after edelfosine or perifosine treatment. (d) Isolated primary tumor MCL cells from nine patients were treated with 10 μℳ perifosine or edelfosine for 24 h. Non-apoptotic cells were quantified as Annexin V-negative cells by flow cytometry, as described in Materials and methods. Untreated controls were run in parallel, and data are represented as percentage of cell viability (means of two experiments) with respect to each untreated control. (e) MCL cells derived from patient no. 3, showing high-sensitivity to ATLs, and from patient no. 8, showing low sensitivity to ATLs, were incubated without (control, C) or with 10 μℳ perifosine (PRIF) or edelfosine (EDLF) for 6 h, and then analyzed by immunoblotting for p-Akt (Ser473) and Akt.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC3674457&req=5

fig6: In vivo anti-MCL activity of edelfosine and perifosine, and effect of ATLs on MCL patient-derived cells. (a) CB17-severe combined immunodeficient mice were inoculated subcutaneously with 107 Z-138 cells, and once palpable tumors were detected, mice were orally treated with vehicle (control), 30 mg/kg edelfosine (EDLF) and 26.45 mg/kg perifosine (PRIF) for 3 weeks. Tumor size was recorded at the indicated times during drug treatment. (b) After completion of the in vivo assay, control mice and animals treated with edelfosine (EDLF) or perifosine (PRIF) were killed, and tumors were isolated and measured (weight and volume). Data in (a) and (b) are shown as mean values±s.d. (n=7). Asterisks indicate significant differences with respect to drug-free control values, at *P<0.05 and **P<0.01. (c) A notable reduction in tumor size was observed after edelfosine or perifosine treatment. (d) Isolated primary tumor MCL cells from nine patients were treated with 10 μℳ perifosine or edelfosine for 24 h. Non-apoptotic cells were quantified as Annexin V-negative cells by flow cytometry, as described in Materials and methods. Untreated controls were run in parallel, and data are represented as percentage of cell viability (means of two experiments) with respect to each untreated control. (e) MCL cells derived from patient no. 3, showing high-sensitivity to ATLs, and from patient no. 8, showing low sensitivity to ATLs, were incubated without (control, C) or with 10 μℳ perifosine (PRIF) or edelfosine (EDLF) for 6 h, and then analyzed by immunoblotting for p-Akt (Ser473) and Akt.
Mentions: By using a xenograft MCL-bearing CB17-severe combined immunodeficient mouse model, we found that daily oral treatment for 3 weeks with ATLs (30 mg/kg edelfosine, molecular mass, 523.70 g/mol; 26.45 mg/kg perifosine, molecular mass, 461.67 g/mol) inhibited the growth of MCL cells. Serial caliper measurements were made to determine tumor growth, and showed a significant anti-MCL activity for both ATLs (Figure 6a). A comparison of tumors, isolated from drug-free control and ATL-treated MCL-bearing mice, at the end of treatment rendered a dramatic reduction of tumor weight and volume in mice treated with edelfosine or perifosine (Figures 6b and c). These results highlight the effectiveness of both edelfosine and perifosine in treating MCL in mice. No significant differences in mean body weight were observed between drug-treated and control animals during the in vivo assay (3–7% of body weight loss in the treated groups versus control groups), suggesting a low toxicity exerted by these two ATLs. This observation is in agreement with a previous report showing lack of significant toxicity of edelfosine in a rat model.48

Bottom Line: The antitumor lipids (ATLs) edelfosine and perifosine target rafts, and we found that ATLs exerted in vitro and in vivo antitumor activity against MCL cells by displacing Akt as well as key regulatory kinases p-PDK1 (phosphatidylinositol-dependent protein kinase 1), PI3K and mTOR (mammalian TOR) from lipid rafts.Microenvironmental stimuli, such as CD40 ligation or stromal cell contact, did not prevent ATL-induced apoptosis in MCL cell lines and patient-derived cells.These results highlight the role of raft-mediated PI3K/Akt signaling in MCL cell survival and chemotherapy, thus becoming a new target for MCL treatment.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, CSIC-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.

ABSTRACT
Recent evidence shows that lipid raft membrane domains modulate both cell survival and death. Here, we have found that the phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway is present in the lipid rafts of mantle cell lymphoma (MCL) cells, and this location seems to be critical for full activation and MCL cell survival. The antitumor lipids (ATLs) edelfosine and perifosine target rafts, and we found that ATLs exerted in vitro and in vivo antitumor activity against MCL cells by displacing Akt as well as key regulatory kinases p-PDK1 (phosphatidylinositol-dependent protein kinase 1), PI3K and mTOR (mammalian TOR) from lipid rafts. This raft reorganization led to Akt dephosphorylation, while proapoptotic Fas/CD95 death receptor was recruited into rafts. Raft integrity was critical for Ser473 Akt phosphorylation. ATL-induced apoptosis appeared to correlate with the basal Akt phosphorylation status in MCL cell lines and primary cultures, and could be potentiated by the PI3K inhibitor wortmannin, or inhibited by the Akt activator pervanadate. Classical Akt inhibitors induced apoptosis in MCL cells. Microenvironmental stimuli, such as CD40 ligation or stromal cell contact, did not prevent ATL-induced apoptosis in MCL cell lines and patient-derived cells. These results highlight the role of raft-mediated PI3K/Akt signaling in MCL cell survival and chemotherapy, thus becoming a new target for MCL treatment.

No MeSH data available.


Related in: MedlinePlus