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A designed peptide targeting CXCR4 displays anti-acute myelocytic leukemia activity in vitro and in vivo.

Li X, Guo H, Yang Y, Meng J, Liu J, Wang C, Xu H - Sci Rep (2014)

Bottom Line: We show that E5 has high affinity to multiple AML cells with high CXCR4 level in a concentration dependent manner.E5 can induce concentration-dependent apoptosis in the four AML cell lines tested while did not affect the viability of MS-5 or human umbilical vein cell (ea.hy926) even at 80 µM, both of which have a low level of CXCR4.In vivo experimental results show that immunocompromised mice transplanted with HL-60 cells survived longer when treated with E5 twice a week in comparison to those treated with cyclophosphamide.

View Article: PubMed Central - PubMed

Affiliation: Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing 100005, P. R. China.

ABSTRACT
Leukemia cells highly expressing chemokine receptor CXCR4 can actively response to stroma derived factor 1α (CXCL12), trafficking and homing to the marrow microenvironment, which causes poor prognosis and relapse. Here we demonstrate that a novel designed peptide (E5) targeting CXCR4 inhibits CXCL12- and stroma-induced activation in multiple acute myelocytic leukemia (AML) cell lines and displays anti-AML activity. We show that E5 has high affinity to multiple AML cells with high CXCR4 level in a concentration dependent manner. E5 significantly inhibits CXCL12- or murine stromal cell (MS-5)-induced migration of leukemia cells and prevents the cells from adhering to stromal cells. Mechanistic studies demonstrate that E5 down-regulates CXCL12-induced phosphorylation of Akt, Erk, and p38, which affects the cytoskeleton F-actin organization and ultimately results in the inhibition of CXCL12- and stroma-mediated leukemia cell responses. E5 can induce concentration-dependent apoptosis in the four AML cell lines tested while did not affect the viability of MS-5 or human umbilical vein cell (ea.hy926) even at 80 µM, both of which have a low level of CXCR4. In vivo experimental results show that immunocompromised mice transplanted with HL-60 cells survived longer when treated with E5 twice a week in comparison to those treated with cyclophosphamide.

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Related in: MedlinePlus

Effects of E5 on CXCL12-induced Erk, Akt and p38 activation of multiple leukemia cells.Lane 1: control, Lane 2: CXCL12 treatment for 10 minutes at 50 ng/mL (THP-1 and U937) or 200 ng/mL (HL-60 and NB4), Lane 3: treated with E5 at 10 µM for 1 h followed by the CXCL12 treatment, Lane 4: E5 treatment at 10 µM for 1 h. Full-length blots are presented in Supplementary Figures.
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f6: Effects of E5 on CXCL12-induced Erk, Akt and p38 activation of multiple leukemia cells.Lane 1: control, Lane 2: CXCL12 treatment for 10 minutes at 50 ng/mL (THP-1 and U937) or 200 ng/mL (HL-60 and NB4), Lane 3: treated with E5 at 10 µM for 1 h followed by the CXCL12 treatment, Lane 4: E5 treatment at 10 µM for 1 h. Full-length blots are presented in Supplementary Figures.

Mentions: The CXCR4/CXCL12 interaction has been demonstrated to trigger Erk, Akt and p38/MAPK signaling, which accounts for the migration and adhesion of leukemia cells conferred by CXCL12263435. To clarify whether E5 inhibits leukemia cells migration and adhesion to the stromal cells through affecting the intracellular signaling of CXCR4/CXCL12, we therefore conducted western blot analysis for activation of Erk (phospho-Erk), Akt (phosphor-Akt) and p38/MAPK (phospho-p38) in the four kinds of leukemia cell. The cells were treated with CXCL12 alone, E5 alone, or E5 prior to CXCL12 treatment. As shown in Figure 6, CXCL12 treatment significantly enhanced the phosphorylation levels of Erk, Akt and p38 (lane 2) in reference to that of control, while E5 not only down-regulated the basal phospho-Erk, phosphor-Akt and phospho-p38 levels (lane 4) but also abrogated the robust phosphorylation of Erk, Akt and p38 in the cells stimulated by CXCL12 (lane 3). These results clearly indicate that E5 inhibits AML cells from responding to CXCL12 stimulation by suppressing the expression of p-Erk, p-Akt and p-p38/MAPK.


A designed peptide targeting CXCR4 displays anti-acute myelocytic leukemia activity in vitro and in vivo.

Li X, Guo H, Yang Y, Meng J, Liu J, Wang C, Xu H - Sci Rep (2014)

Effects of E5 on CXCL12-induced Erk, Akt and p38 activation of multiple leukemia cells.Lane 1: control, Lane 2: CXCL12 treatment for 10 minutes at 50 ng/mL (THP-1 and U937) or 200 ng/mL (HL-60 and NB4), Lane 3: treated with E5 at 10 µM for 1 h followed by the CXCL12 treatment, Lane 4: E5 treatment at 10 µM for 1 h. Full-length blots are presented in Supplementary Figures.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196105&req=5

f6: Effects of E5 on CXCL12-induced Erk, Akt and p38 activation of multiple leukemia cells.Lane 1: control, Lane 2: CXCL12 treatment for 10 minutes at 50 ng/mL (THP-1 and U937) or 200 ng/mL (HL-60 and NB4), Lane 3: treated with E5 at 10 µM for 1 h followed by the CXCL12 treatment, Lane 4: E5 treatment at 10 µM for 1 h. Full-length blots are presented in Supplementary Figures.
Mentions: The CXCR4/CXCL12 interaction has been demonstrated to trigger Erk, Akt and p38/MAPK signaling, which accounts for the migration and adhesion of leukemia cells conferred by CXCL12263435. To clarify whether E5 inhibits leukemia cells migration and adhesion to the stromal cells through affecting the intracellular signaling of CXCR4/CXCL12, we therefore conducted western blot analysis for activation of Erk (phospho-Erk), Akt (phosphor-Akt) and p38/MAPK (phospho-p38) in the four kinds of leukemia cell. The cells were treated with CXCL12 alone, E5 alone, or E5 prior to CXCL12 treatment. As shown in Figure 6, CXCL12 treatment significantly enhanced the phosphorylation levels of Erk, Akt and p38 (lane 2) in reference to that of control, while E5 not only down-regulated the basal phospho-Erk, phosphor-Akt and phospho-p38 levels (lane 4) but also abrogated the robust phosphorylation of Erk, Akt and p38 in the cells stimulated by CXCL12 (lane 3). These results clearly indicate that E5 inhibits AML cells from responding to CXCL12 stimulation by suppressing the expression of p-Erk, p-Akt and p-p38/MAPK.

Bottom Line: We show that E5 has high affinity to multiple AML cells with high CXCR4 level in a concentration dependent manner.E5 can induce concentration-dependent apoptosis in the four AML cell lines tested while did not affect the viability of MS-5 or human umbilical vein cell (ea.hy926) even at 80 µM, both of which have a low level of CXCR4.In vivo experimental results show that immunocompromised mice transplanted with HL-60 cells survived longer when treated with E5 twice a week in comparison to those treated with cyclophosphamide.

View Article: PubMed Central - PubMed

Affiliation: Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences &Peking Union Medical College, Beijing 100005, P. R. China.

ABSTRACT
Leukemia cells highly expressing chemokine receptor CXCR4 can actively response to stroma derived factor 1α (CXCL12), trafficking and homing to the marrow microenvironment, which causes poor prognosis and relapse. Here we demonstrate that a novel designed peptide (E5) targeting CXCR4 inhibits CXCL12- and stroma-induced activation in multiple acute myelocytic leukemia (AML) cell lines and displays anti-AML activity. We show that E5 has high affinity to multiple AML cells with high CXCR4 level in a concentration dependent manner. E5 significantly inhibits CXCL12- or murine stromal cell (MS-5)-induced migration of leukemia cells and prevents the cells from adhering to stromal cells. Mechanistic studies demonstrate that E5 down-regulates CXCL12-induced phosphorylation of Akt, Erk, and p38, which affects the cytoskeleton F-actin organization and ultimately results in the inhibition of CXCL12- and stroma-mediated leukemia cell responses. E5 can induce concentration-dependent apoptosis in the four AML cell lines tested while did not affect the viability of MS-5 or human umbilical vein cell (ea.hy926) even at 80 µM, both of which have a low level of CXCR4. In vivo experimental results show that immunocompromised mice transplanted with HL-60 cells survived longer when treated with E5 twice a week in comparison to those treated with cyclophosphamide.

Show MeSH
Related in: MedlinePlus