Limits...
Sulindac sulfide reverses aberrant self-renewal of progenitor cells induced by the AML-associated fusion proteins PML/RARα and PLZF/RARα.

Steinert G, Oancea C, Roos J, Hagemeyer H, Maier T, Ruthardt M, Puccetti E - PLoS ONE (2011)

Bottom Line: Furthermore, a reduction in leukemia risk was associated with use of non-steroidal anti-inflammatory drug (NSAID), where the effects on AML risk was FAB subtype-specific.Sulindac Sulfide (SSi) is a derivative of Sulindac, a NSAID known to inactivate Wnt signaling.We found that SSi downregulated both β-catenin and γ-catenin in X-RARα-expressing cells and reversed the leukemic phenotype by reducing stem cell capacity and increasing differentiation potential in X-RARα-positive HSCs.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology, Goethe-University, Frankfurt, Germany.

ABSTRACT
Chromosomal translocations can lead to the formation of chimeric genes encoding fusion proteins such as PML/RARα, PLZF/RARα, and AML-1/ETO, which are able to induce and maintain acute myeloid leukemia (AML). One key mechanism in leukemogenesis is increased self renewal of leukemic stem cells via aberrant activation of the Wnt signaling pathway. Either X-RAR, PML/RARα and PLZF/RARα or AML-1/ETO activate Wnt signaling by upregulating γ-catenin and β-catenin. In a prospective study, a lower risk of leukemia was observed with aspirin use, which is consistent with numerous studies reporting an inverse association of aspirin with other cancers. Furthermore, a reduction in leukemia risk was associated with use of non-steroidal anti-inflammatory drug (NSAID), where the effects on AML risk was FAB subtype-specific. To better investigate whether NSAID treatment is effective, we used Sulindac Sulfide in X-RARα-positive progenitor cell models. Sulindac Sulfide (SSi) is a derivative of Sulindac, a NSAID known to inactivate Wnt signaling. We found that SSi downregulated both β-catenin and γ-catenin in X-RARα-expressing cells and reversed the leukemic phenotype by reducing stem cell capacity and increasing differentiation potential in X-RARα-positive HSCs. The data presented herein show that SSi inhibits the leukemic cell growth as well as hematopoietic progenitors cells (HPCs) expressing PML/RARα, and it indicates that Sulindac is a valid molecular therapeutic approach that should be further validated using in vivo leukemia models and in clinical settings.

Show MeSH

Related in: MedlinePlus

Effect of SSi on the X-RARα-induced phenotype in murine HSCs.(A) Experimental strategy. Sca1+/lin- BM cells were infected with the indicated retroviruses and maintained for one week in liquid culture with the indicated growth factors in the presence/absence of 40 µM SSi. (B) Differentiation was assessed by the expression of Gr-1, Mac-1, c-Kit and Sca1. (C) Schematic representation of the proliferation competition assay (PCA). (D) GFP expression in X-RARα-positive HPCs assessed by FACS analysis in the presence/absence of SSi at day 2, 4, and 7. One representative result from three independent experiments is shown.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3139642&req=5

pone-0022540-g005: Effect of SSi on the X-RARα-induced phenotype in murine HSCs.(A) Experimental strategy. Sca1+/lin- BM cells were infected with the indicated retroviruses and maintained for one week in liquid culture with the indicated growth factors in the presence/absence of 40 µM SSi. (B) Differentiation was assessed by the expression of Gr-1, Mac-1, c-Kit and Sca1. (C) Schematic representation of the proliferation competition assay (PCA). (D) GFP expression in X-RARα-positive HPCs assessed by FACS analysis in the presence/absence of SSi at day 2, 4, and 7. One representative result from three independent experiments is shown.

Mentions: One feature of the leukemic phenotype is inhibited differentiation of early hematopoietic precursors. X-RARα inhibits terminal differentiation in murine HSCs [3]. To study whether the effects of SSi on replating efficiency leukemic HPCs were caused by reversal of the differentiation block, we investigated the effects of clinical doses of SSi on differentiation of X-RARα-expressing Sca1+/lin− HPCs (Figure 5A). Differentiation was assessed by expression of specific surface markers such as Gr-1, Mac-1, Sca1, and c-Kit. We performed these experiments in liquid culture to demonstrate the effects of SSi on mock-transduced control HPCs, which should fully differentiate spontaneously in semi-solid medium. We found that SSi induced differentiation despite the presence of X-RARα, as demonstrated by an increase in Gr-1+ and Mac-1+ and decrease in Sca1+ and c-Kit+ cells (Figure 5B). To assess whether SSi-induced differentiation interfered with HSC proliferation, we performed PCA experiments that compared X-RARα-expressing HPCs to an empty vector control. The principle of the assay is depicted in Figure 5C; HPCs were transduced with the PINCO constructs, in which the LTR drives transgene expression. GFP expression is driven by a CMV promoter. The effect of SSi was demonstrated by detecting GFP-positive cells using FACS at 1 week. We found that SSi exposure led to reduced proliferation of X-RARα-positive HPCs, with no such effect on control cells (Figure 5D).


Sulindac sulfide reverses aberrant self-renewal of progenitor cells induced by the AML-associated fusion proteins PML/RARα and PLZF/RARα.

Steinert G, Oancea C, Roos J, Hagemeyer H, Maier T, Ruthardt M, Puccetti E - PLoS ONE (2011)

Effect of SSi on the X-RARα-induced phenotype in murine HSCs.(A) Experimental strategy. Sca1+/lin- BM cells were infected with the indicated retroviruses and maintained for one week in liquid culture with the indicated growth factors in the presence/absence of 40 µM SSi. (B) Differentiation was assessed by the expression of Gr-1, Mac-1, c-Kit and Sca1. (C) Schematic representation of the proliferation competition assay (PCA). (D) GFP expression in X-RARα-positive HPCs assessed by FACS analysis in the presence/absence of SSi at day 2, 4, and 7. One representative result from three independent experiments is shown.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3139642&req=5

pone-0022540-g005: Effect of SSi on the X-RARα-induced phenotype in murine HSCs.(A) Experimental strategy. Sca1+/lin- BM cells were infected with the indicated retroviruses and maintained for one week in liquid culture with the indicated growth factors in the presence/absence of 40 µM SSi. (B) Differentiation was assessed by the expression of Gr-1, Mac-1, c-Kit and Sca1. (C) Schematic representation of the proliferation competition assay (PCA). (D) GFP expression in X-RARα-positive HPCs assessed by FACS analysis in the presence/absence of SSi at day 2, 4, and 7. One representative result from three independent experiments is shown.
Mentions: One feature of the leukemic phenotype is inhibited differentiation of early hematopoietic precursors. X-RARα inhibits terminal differentiation in murine HSCs [3]. To study whether the effects of SSi on replating efficiency leukemic HPCs were caused by reversal of the differentiation block, we investigated the effects of clinical doses of SSi on differentiation of X-RARα-expressing Sca1+/lin− HPCs (Figure 5A). Differentiation was assessed by expression of specific surface markers such as Gr-1, Mac-1, Sca1, and c-Kit. We performed these experiments in liquid culture to demonstrate the effects of SSi on mock-transduced control HPCs, which should fully differentiate spontaneously in semi-solid medium. We found that SSi induced differentiation despite the presence of X-RARα, as demonstrated by an increase in Gr-1+ and Mac-1+ and decrease in Sca1+ and c-Kit+ cells (Figure 5B). To assess whether SSi-induced differentiation interfered with HSC proliferation, we performed PCA experiments that compared X-RARα-expressing HPCs to an empty vector control. The principle of the assay is depicted in Figure 5C; HPCs were transduced with the PINCO constructs, in which the LTR drives transgene expression. GFP expression is driven by a CMV promoter. The effect of SSi was demonstrated by detecting GFP-positive cells using FACS at 1 week. We found that SSi exposure led to reduced proliferation of X-RARα-positive HPCs, with no such effect on control cells (Figure 5D).

Bottom Line: Furthermore, a reduction in leukemia risk was associated with use of non-steroidal anti-inflammatory drug (NSAID), where the effects on AML risk was FAB subtype-specific.Sulindac Sulfide (SSi) is a derivative of Sulindac, a NSAID known to inactivate Wnt signaling.We found that SSi downregulated both β-catenin and γ-catenin in X-RARα-expressing cells and reversed the leukemic phenotype by reducing stem cell capacity and increasing differentiation potential in X-RARα-positive HSCs.

View Article: PubMed Central - PubMed

Affiliation: Department of Hematology, Goethe-University, Frankfurt, Germany.

ABSTRACT
Chromosomal translocations can lead to the formation of chimeric genes encoding fusion proteins such as PML/RARα, PLZF/RARα, and AML-1/ETO, which are able to induce and maintain acute myeloid leukemia (AML). One key mechanism in leukemogenesis is increased self renewal of leukemic stem cells via aberrant activation of the Wnt signaling pathway. Either X-RAR, PML/RARα and PLZF/RARα or AML-1/ETO activate Wnt signaling by upregulating γ-catenin and β-catenin. In a prospective study, a lower risk of leukemia was observed with aspirin use, which is consistent with numerous studies reporting an inverse association of aspirin with other cancers. Furthermore, a reduction in leukemia risk was associated with use of non-steroidal anti-inflammatory drug (NSAID), where the effects on AML risk was FAB subtype-specific. To better investigate whether NSAID treatment is effective, we used Sulindac Sulfide in X-RARα-positive progenitor cell models. Sulindac Sulfide (SSi) is a derivative of Sulindac, a NSAID known to inactivate Wnt signaling. We found that SSi downregulated both β-catenin and γ-catenin in X-RARα-expressing cells and reversed the leukemic phenotype by reducing stem cell capacity and increasing differentiation potential in X-RARα-positive HSCs. The data presented herein show that SSi inhibits the leukemic cell growth as well as hematopoietic progenitors cells (HPCs) expressing PML/RARα, and it indicates that Sulindac is a valid molecular therapeutic approach that should be further validated using in vivo leukemia models and in clinical settings.

Show MeSH
Related in: MedlinePlus