Limits...
Gamma-secretase inhibitors reverse glucocorticoid resistance in T cell acute lymphoblastic leukemia.

Real PJ, Tosello V, Palomero T, Castillo M, Hernando E, de Stanchina E, Sulis ML, Barnes K, Sawai C, Homminga I, Meijerink J, Aifantis I, Basso G, Cordon-Cardo C, Ai W, Ferrando A - Nat. Med. (2008)

Bottom Line: Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo.GSI treatment resulted in cell cycle arrest and accumulation of goblet cells in the gut mediated by upregulation of the gene encoding the transcription factor Krüppel-like factor-4 (Klf4), a negative regulator of the cell cycle required for goblet cell differentiation.In contrast, glucocorticoid treatment induced transcriptional upregulation of cyclin D2 (Ccnd2) and protected mice from developing the intestinal goblet cell metaplasia typically induced by inhibition of NOTCH signaling with GSIs.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA.

ABSTRACT
Gamma-secretase inhibitors (GSIs) block the activation of the oncogenic protein Notch homolog-1 (NOTCH1) in T cell acute lymphoblastic leukemia (T-ALL). However, limited antileukemic cytotoxicity and severe gastrointestinal toxicity have restricted the clinical application of these targeted drugs. Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo. Inhibition of NOTCH1 signaling in glucocorticoid-resistant T-ALL restored glucocorticoid receptor autoupregulation and induced apoptotic cell death through induction of the gene encoding BCL-2-like apoptosis initiator-11 (BCL2L11). GSI treatment resulted in cell cycle arrest and accumulation of goblet cells in the gut mediated by upregulation of the gene encoding the transcription factor Krüppel-like factor-4 (Klf4), a negative regulator of the cell cycle required for goblet cell differentiation. In contrast, glucocorticoid treatment induced transcriptional upregulation of cyclin D2 (Ccnd2) and protected mice from developing the intestinal goblet cell metaplasia typically induced by inhibition of NOTCH signaling with GSIs. These results support a role for glucocorticoids plus GSIs in the treatment of glucocorticoid-resistant T-ALL.

Show MeSH

Related in: MedlinePlus

Interaction of NOTCH inhibition and dexamethasone treatment in tumor response and gut toxicity in vivo. (a) Bioimaging quantitation of tumor mass changes in subcutaneous CUTLL1 T-ALL xenografts in mice treated with vehicle (control), dexamethasone, GSI (DBZ) or GSI plus dexamethasone (Dexamethasone + DBZ) for 4 days. (b) Representative examples of bioluminiscence in vivo imaging showing changes in tumor load in representative mice (animals with closest values to the median are shown) treated with vehicle (control), dexamethasone (Dexa), DBZ and dexamethasone plus DBZ (Dexa + DBZ). (c) Tumor mass changes induced by dexamethasone plus DBZ treatment compared to controls in CUTLL1 T-ALL xenografts (CUTLL1) and CUTLL1 xenografts expressing an intracellular form of NOTCH1 (CUTLL1 ICN1), which does not require γ-secretase cleavage for activation. (d) Kaplan-Meier plot of overall survival among mice treated with vehicle (Control), dexamethasone, DBZ or DBZ plus dexamethasone after xenograft transplantation of human T-ALL cells via tail vein injection. (e) Histological analysis of small intestine, spleen and thymus from mice treated with vehicle, dexamethasone, DBZ and dexamethasone plus DBZ for 5 days. (f) Goblet cell analysis and quantitation in the ileum of RBPJ(fl/fl) Cre-Tam conditional knockout mice in basal conditions (RBPJ(fl/fl) Cre-Tam), following conditional deletion of CSL/RBPJ with tamoxifen (RBPJ(fl/fl) Cre-Tam TMX) and upon conditional deletion of CSL/RBPJ followed by dexamethasone treatment (RBPJ(fl/fl) Cre-Tam TMX + Dexa). TMX: tamoxifen. H&E: haemotoxylin and eosin staining. Scale bars represent 100 µm in the intestine and 400 µm in spleen and thymus.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2692090&req=5

Figure 4: Interaction of NOTCH inhibition and dexamethasone treatment in tumor response and gut toxicity in vivo. (a) Bioimaging quantitation of tumor mass changes in subcutaneous CUTLL1 T-ALL xenografts in mice treated with vehicle (control), dexamethasone, GSI (DBZ) or GSI plus dexamethasone (Dexamethasone + DBZ) for 4 days. (b) Representative examples of bioluminiscence in vivo imaging showing changes in tumor load in representative mice (animals with closest values to the median are shown) treated with vehicle (control), dexamethasone (Dexa), DBZ and dexamethasone plus DBZ (Dexa + DBZ). (c) Tumor mass changes induced by dexamethasone plus DBZ treatment compared to controls in CUTLL1 T-ALL xenografts (CUTLL1) and CUTLL1 xenografts expressing an intracellular form of NOTCH1 (CUTLL1 ICN1), which does not require γ-secretase cleavage for activation. (d) Kaplan-Meier plot of overall survival among mice treated with vehicle (Control), dexamethasone, DBZ or DBZ plus dexamethasone after xenograft transplantation of human T-ALL cells via tail vein injection. (e) Histological analysis of small intestine, spleen and thymus from mice treated with vehicle, dexamethasone, DBZ and dexamethasone plus DBZ for 5 days. (f) Goblet cell analysis and quantitation in the ileum of RBPJ(fl/fl) Cre-Tam conditional knockout mice in basal conditions (RBPJ(fl/fl) Cre-Tam), following conditional deletion of CSL/RBPJ with tamoxifen (RBPJ(fl/fl) Cre-Tam TMX) and upon conditional deletion of CSL/RBPJ followed by dexamethasone treatment (RBPJ(fl/fl) Cre-Tam TMX + Dexa). TMX: tamoxifen. H&E: haemotoxylin and eosin staining. Scale bars represent 100 µm in the intestine and 400 µm in spleen and thymus.

Mentions: To test whether the synergistic effects of GSI and glucocorticoid cotreatment in vitro would enhance the therapeutic efficacy of these agents in vivo, we analyzed the effects of dexamethasone and NOTCH inhibition in a xenograft model of glucocorticoid-resistant T-ALL. In these experiments we used DBZ, a highly active GSI, analogous to CompE in vitro (Supplementary Fig. 9 online) and with well established activity in vivo8. CUTLL1 cells infected with lentiviruses expressing the luciferase gene were injected subcutaneously in the flanks of immunodeficient (NOD/SCID) mice. After 1 week, animals harboring homogeneous subcutaneous tumors were treated with vehicle only (DMSO), DBZ, dexamethasone or DBZ plus dexamethasone and monitored for 4 days with a bioimaging system to quantify luciferase activity. In this experiment, animals treated with dexamethasone showed progressive tumor growth similar to that observed in vehicle-treated controls, while mice treated with DBZ showed a moderate delay in tumor growth (Fig. 4a,b) consistent with the cytostatic effect of NOTCH1 inhibition with GSIs observed in CUTLL1 cells in vitro (Supplementary Fig. 1 online) 6. By contrast, animals treated with DBZ plus dexamethasone had marked antitumor responses with significant reduction in tumor burden after 4 days of treatment (Fig. 4a,b; P < 0.01). Importantly, tumor xenografts of CUTLL1 cells expressing the activated intracellular form of NOTCH1 (CUTLL1-ICN1) (Supplementary Fig. 4 online) were unresponsive to the combination of DBZ plus dexamethasone (Fig. 4c), indicating that reversal of glucocorticoid resistance in vivo by DBZ treatment is mediated by inhibition of NOTCH1 signaling in the leukemic cells.


Gamma-secretase inhibitors reverse glucocorticoid resistance in T cell acute lymphoblastic leukemia.

Real PJ, Tosello V, Palomero T, Castillo M, Hernando E, de Stanchina E, Sulis ML, Barnes K, Sawai C, Homminga I, Meijerink J, Aifantis I, Basso G, Cordon-Cardo C, Ai W, Ferrando A - Nat. Med. (2008)

Interaction of NOTCH inhibition and dexamethasone treatment in tumor response and gut toxicity in vivo. (a) Bioimaging quantitation of tumor mass changes in subcutaneous CUTLL1 T-ALL xenografts in mice treated with vehicle (control), dexamethasone, GSI (DBZ) or GSI plus dexamethasone (Dexamethasone + DBZ) for 4 days. (b) Representative examples of bioluminiscence in vivo imaging showing changes in tumor load in representative mice (animals with closest values to the median are shown) treated with vehicle (control), dexamethasone (Dexa), DBZ and dexamethasone plus DBZ (Dexa + DBZ). (c) Tumor mass changes induced by dexamethasone plus DBZ treatment compared to controls in CUTLL1 T-ALL xenografts (CUTLL1) and CUTLL1 xenografts expressing an intracellular form of NOTCH1 (CUTLL1 ICN1), which does not require γ-secretase cleavage for activation. (d) Kaplan-Meier plot of overall survival among mice treated with vehicle (Control), dexamethasone, DBZ or DBZ plus dexamethasone after xenograft transplantation of human T-ALL cells via tail vein injection. (e) Histological analysis of small intestine, spleen and thymus from mice treated with vehicle, dexamethasone, DBZ and dexamethasone plus DBZ for 5 days. (f) Goblet cell analysis and quantitation in the ileum of RBPJ(fl/fl) Cre-Tam conditional knockout mice in basal conditions (RBPJ(fl/fl) Cre-Tam), following conditional deletion of CSL/RBPJ with tamoxifen (RBPJ(fl/fl) Cre-Tam TMX) and upon conditional deletion of CSL/RBPJ followed by dexamethasone treatment (RBPJ(fl/fl) Cre-Tam TMX + Dexa). TMX: tamoxifen. H&E: haemotoxylin and eosin staining. Scale bars represent 100 µm in the intestine and 400 µm in spleen and thymus.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2692090&req=5

Figure 4: Interaction of NOTCH inhibition and dexamethasone treatment in tumor response and gut toxicity in vivo. (a) Bioimaging quantitation of tumor mass changes in subcutaneous CUTLL1 T-ALL xenografts in mice treated with vehicle (control), dexamethasone, GSI (DBZ) or GSI plus dexamethasone (Dexamethasone + DBZ) for 4 days. (b) Representative examples of bioluminiscence in vivo imaging showing changes in tumor load in representative mice (animals with closest values to the median are shown) treated with vehicle (control), dexamethasone (Dexa), DBZ and dexamethasone plus DBZ (Dexa + DBZ). (c) Tumor mass changes induced by dexamethasone plus DBZ treatment compared to controls in CUTLL1 T-ALL xenografts (CUTLL1) and CUTLL1 xenografts expressing an intracellular form of NOTCH1 (CUTLL1 ICN1), which does not require γ-secretase cleavage for activation. (d) Kaplan-Meier plot of overall survival among mice treated with vehicle (Control), dexamethasone, DBZ or DBZ plus dexamethasone after xenograft transplantation of human T-ALL cells via tail vein injection. (e) Histological analysis of small intestine, spleen and thymus from mice treated with vehicle, dexamethasone, DBZ and dexamethasone plus DBZ for 5 days. (f) Goblet cell analysis and quantitation in the ileum of RBPJ(fl/fl) Cre-Tam conditional knockout mice in basal conditions (RBPJ(fl/fl) Cre-Tam), following conditional deletion of CSL/RBPJ with tamoxifen (RBPJ(fl/fl) Cre-Tam TMX) and upon conditional deletion of CSL/RBPJ followed by dexamethasone treatment (RBPJ(fl/fl) Cre-Tam TMX + Dexa). TMX: tamoxifen. H&E: haemotoxylin and eosin staining. Scale bars represent 100 µm in the intestine and 400 µm in spleen and thymus.
Mentions: To test whether the synergistic effects of GSI and glucocorticoid cotreatment in vitro would enhance the therapeutic efficacy of these agents in vivo, we analyzed the effects of dexamethasone and NOTCH inhibition in a xenograft model of glucocorticoid-resistant T-ALL. In these experiments we used DBZ, a highly active GSI, analogous to CompE in vitro (Supplementary Fig. 9 online) and with well established activity in vivo8. CUTLL1 cells infected with lentiviruses expressing the luciferase gene were injected subcutaneously in the flanks of immunodeficient (NOD/SCID) mice. After 1 week, animals harboring homogeneous subcutaneous tumors were treated with vehicle only (DMSO), DBZ, dexamethasone or DBZ plus dexamethasone and monitored for 4 days with a bioimaging system to quantify luciferase activity. In this experiment, animals treated with dexamethasone showed progressive tumor growth similar to that observed in vehicle-treated controls, while mice treated with DBZ showed a moderate delay in tumor growth (Fig. 4a,b) consistent with the cytostatic effect of NOTCH1 inhibition with GSIs observed in CUTLL1 cells in vitro (Supplementary Fig. 1 online) 6. By contrast, animals treated with DBZ plus dexamethasone had marked antitumor responses with significant reduction in tumor burden after 4 days of treatment (Fig. 4a,b; P < 0.01). Importantly, tumor xenografts of CUTLL1 cells expressing the activated intracellular form of NOTCH1 (CUTLL1-ICN1) (Supplementary Fig. 4 online) were unresponsive to the combination of DBZ plus dexamethasone (Fig. 4c), indicating that reversal of glucocorticoid resistance in vivo by DBZ treatment is mediated by inhibition of NOTCH1 signaling in the leukemic cells.

Bottom Line: Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo.GSI treatment resulted in cell cycle arrest and accumulation of goblet cells in the gut mediated by upregulation of the gene encoding the transcription factor Krüppel-like factor-4 (Klf4), a negative regulator of the cell cycle required for goblet cell differentiation.In contrast, glucocorticoid treatment induced transcriptional upregulation of cyclin D2 (Ccnd2) and protected mice from developing the intestinal goblet cell metaplasia typically induced by inhibition of NOTCH signaling with GSIs.

View Article: PubMed Central - PubMed

Affiliation: Institute for Cancer Genetics, Columbia University, New York, NY 10032, USA.

ABSTRACT
Gamma-secretase inhibitors (GSIs) block the activation of the oncogenic protein Notch homolog-1 (NOTCH1) in T cell acute lymphoblastic leukemia (T-ALL). However, limited antileukemic cytotoxicity and severe gastrointestinal toxicity have restricted the clinical application of these targeted drugs. Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo. Inhibition of NOTCH1 signaling in glucocorticoid-resistant T-ALL restored glucocorticoid receptor autoupregulation and induced apoptotic cell death through induction of the gene encoding BCL-2-like apoptosis initiator-11 (BCL2L11). GSI treatment resulted in cell cycle arrest and accumulation of goblet cells in the gut mediated by upregulation of the gene encoding the transcription factor Krüppel-like factor-4 (Klf4), a negative regulator of the cell cycle required for goblet cell differentiation. In contrast, glucocorticoid treatment induced transcriptional upregulation of cyclin D2 (Ccnd2) and protected mice from developing the intestinal goblet cell metaplasia typically induced by inhibition of NOTCH signaling with GSIs. These results support a role for glucocorticoids plus GSIs in the treatment of glucocorticoid-resistant T-ALL.

Show MeSH
Related in: MedlinePlus