THE RETINOID DRUG ACITRETIN UPREGULATES CD38 EXPRESSION IN CHRONIC LYMPHOCYTIC LEUKEMIA AND MEC-1 CELLS AND REDUCES CELL HOMING TOWARDS THE CHEMOKINE CXCL12 : POTENTIAL FOR EXPLOITATION IN THERAPY
(Abstract release date: 05/19/16)
EHA Library. Elsir Mohammed S. 06/09/16; 132587; E1038
Sally Elsir Mohammed
Contributions
Contributions
Abstract
Abstract: E1038
Type: Eposter Presentation
Background
CD38 expression is a robust prognostic indicator in Chronic Lymphocytic Leukemia(CLL) and has gained importance among the repertoire of markers utilised to aid management decisions in CLL. The CD38 molecule is also attracting interest as a mark for targeted therapies, namely anti-CD38 monoclonal antibody treatment. Retinoids modulate CD38 expression due to the presence of the Retinoic Acid Response Element (RARE) DNA sequence in intron 1 of the CD38 gene. Several studies have investigated this effect in myeloid malignancies however little is known about retinoid effect on lymphoid malignancies.
Aims
In this study we demonstrate that the retinoic acid derivative, acitretin, upregulates the expression of CD38 on the MEC-1 cell line and on primary CLL cells from CD38 positive patients. We propose that by doing so, acitretin may render these cells more susceptible to the actions of anti CD38 monoclonal antibody drugs and thus have a potential role as an adjunct to such therapies. We also show that acitretin reduces CLL cell homing in response to the chemokine CXCL12, therefore potentially preventing cells from reaching the micro environment niche and may as a result, lead to shortened survival.
Methods
Ethical approval for the study was obtained from the ethical committee in Beaumont University Hospital. Peripheral blood samples were collected from 32 patients with a confirmed diagnosis of CLL and who had given written informed consent. MEC-1 cells were obtained from DSMZ, Germany. MEC-1 cells and cells from five CD38 negative and five CD38 positive patients were treated with 10µM acitretin for 24 and 72 hours. CD38 expression was measured by flow cytometric analysis at baseline and at the different time points. Results are expressed as fold difference in Mean Fluorescence Intensity (MFI) in treated versus untreated cells. Migration assays were performed using 2x106 cells per well incubated with either 10µM acitretin or media, overnight in 1%FBS. Cells were subsequently transferred to chamber inserts overlying 10%FBS media containing 200ng/ml CXCL12 in all wells, except negative controls. Cells were allowed to migrate for 4hrs. Migration was calculated as percentage of cells in lower chamber to upper chamber.
Results
CD38 expression in MEC-1 cells was significantly upregulated in cells incubated with 10µM acitretin for 72 hours, (6.89 fold higher expression in acitretin treated cells compared to controls, n=3,**p=0.00075). In primary cells derived from patient samples that had CD38 expression ≥ 9% at baseline, acitretin produced an increase in CD38 expression that was 2.25 fold higher compared to untreated cells(n=5,* p=.022). However, in primary cells from patient samples with CD38 expression <9% at baseline, the effect of acitretin was only 1.53 higher CD38 expression in cells treated with 10µM acitretin at 72 hours. Significant modulation of CD38 expression in these cells was only achieved in the cells treated with 50µM acitretin for 72 hours (*p=.022).In cell migration, acitretin treatment resulted in a significant reduction in CLL cell homing toward CXCL12 in 14 out of 17 patient samples. Mean relative migration was reduced from 23.5% to 11.9% of input cells (11.6% reduction, **p=.00018, n=14, mean +/- SEM).These were cell samples from a varied group of patients that included 8(54%) from previously treated, relapsed patients and 6(43%) treatment naïve patient samples.
Conclusion
CD38 expression is significantly unregulated by acitretin in CLL cells expressing CD38 at baseline. We suggest this would prove advantageous in the setting of anti-CD38 monoclonal antibody therapy through improving efficacy of this drug, and should be studied further in CLL. Acitretin also reduced the homing ability of CLL cells towards the chemoattractant CXCL12, the mechanism and potential therapeutic implications of which needs to be further explored.
Session topic: E-poster
Keyword(s): CD38, Chronic lymphocytic leukemia, Retinoic acid
Type: Eposter Presentation
Background
CD38 expression is a robust prognostic indicator in Chronic Lymphocytic Leukemia(CLL) and has gained importance among the repertoire of markers utilised to aid management decisions in CLL. The CD38 molecule is also attracting interest as a mark for targeted therapies, namely anti-CD38 monoclonal antibody treatment. Retinoids modulate CD38 expression due to the presence of the Retinoic Acid Response Element (RARE) DNA sequence in intron 1 of the CD38 gene. Several studies have investigated this effect in myeloid malignancies however little is known about retinoid effect on lymphoid malignancies.
Aims
In this study we demonstrate that the retinoic acid derivative, acitretin, upregulates the expression of CD38 on the MEC-1 cell line and on primary CLL cells from CD38 positive patients. We propose that by doing so, acitretin may render these cells more susceptible to the actions of anti CD38 monoclonal antibody drugs and thus have a potential role as an adjunct to such therapies. We also show that acitretin reduces CLL cell homing in response to the chemokine CXCL12, therefore potentially preventing cells from reaching the micro environment niche and may as a result, lead to shortened survival.
Methods
Ethical approval for the study was obtained from the ethical committee in Beaumont University Hospital. Peripheral blood samples were collected from 32 patients with a confirmed diagnosis of CLL and who had given written informed consent. MEC-1 cells were obtained from DSMZ, Germany. MEC-1 cells and cells from five CD38 negative and five CD38 positive patients were treated with 10µM acitretin for 24 and 72 hours. CD38 expression was measured by flow cytometric analysis at baseline and at the different time points. Results are expressed as fold difference in Mean Fluorescence Intensity (MFI) in treated versus untreated cells. Migration assays were performed using 2x106 cells per well incubated with either 10µM acitretin or media, overnight in 1%FBS. Cells were subsequently transferred to chamber inserts overlying 10%FBS media containing 200ng/ml CXCL12 in all wells, except negative controls. Cells were allowed to migrate for 4hrs. Migration was calculated as percentage of cells in lower chamber to upper chamber.
Results
CD38 expression in MEC-1 cells was significantly upregulated in cells incubated with 10µM acitretin for 72 hours, (6.89 fold higher expression in acitretin treated cells compared to controls, n=3,**p=0.00075). In primary cells derived from patient samples that had CD38 expression ≥ 9% at baseline, acitretin produced an increase in CD38 expression that was 2.25 fold higher compared to untreated cells(n=5,* p=.022). However, in primary cells from patient samples with CD38 expression <9% at baseline, the effect of acitretin was only 1.53 higher CD38 expression in cells treated with 10µM acitretin at 72 hours. Significant modulation of CD38 expression in these cells was only achieved in the cells treated with 50µM acitretin for 72 hours (*p=.022).In cell migration, acitretin treatment resulted in a significant reduction in CLL cell homing toward CXCL12 in 14 out of 17 patient samples. Mean relative migration was reduced from 23.5% to 11.9% of input cells (11.6% reduction, **p=.00018, n=14, mean +/- SEM).These were cell samples from a varied group of patients that included 8(54%) from previously treated, relapsed patients and 6(43%) treatment naïve patient samples.
Conclusion
CD38 expression is significantly unregulated by acitretin in CLL cells expressing CD38 at baseline. We suggest this would prove advantageous in the setting of anti-CD38 monoclonal antibody therapy through improving efficacy of this drug, and should be studied further in CLL. Acitretin also reduced the homing ability of CLL cells towards the chemoattractant CXCL12, the mechanism and potential therapeutic implications of which needs to be further explored.
Session topic: E-poster
Keyword(s): CD38, Chronic lymphocytic leukemia, Retinoic acid
Abstract: E1038
Type: Eposter Presentation
Background
CD38 expression is a robust prognostic indicator in Chronic Lymphocytic Leukemia(CLL) and has gained importance among the repertoire of markers utilised to aid management decisions in CLL. The CD38 molecule is also attracting interest as a mark for targeted therapies, namely anti-CD38 monoclonal antibody treatment. Retinoids modulate CD38 expression due to the presence of the Retinoic Acid Response Element (RARE) DNA sequence in intron 1 of the CD38 gene. Several studies have investigated this effect in myeloid malignancies however little is known about retinoid effect on lymphoid malignancies.
Aims
In this study we demonstrate that the retinoic acid derivative, acitretin, upregulates the expression of CD38 on the MEC-1 cell line and on primary CLL cells from CD38 positive patients. We propose that by doing so, acitretin may render these cells more susceptible to the actions of anti CD38 monoclonal antibody drugs and thus have a potential role as an adjunct to such therapies. We also show that acitretin reduces CLL cell homing in response to the chemokine CXCL12, therefore potentially preventing cells from reaching the micro environment niche and may as a result, lead to shortened survival.
Methods
Ethical approval for the study was obtained from the ethical committee in Beaumont University Hospital. Peripheral blood samples were collected from 32 patients with a confirmed diagnosis of CLL and who had given written informed consent. MEC-1 cells were obtained from DSMZ, Germany. MEC-1 cells and cells from five CD38 negative and five CD38 positive patients were treated with 10µM acitretin for 24 and 72 hours. CD38 expression was measured by flow cytometric analysis at baseline and at the different time points. Results are expressed as fold difference in Mean Fluorescence Intensity (MFI) in treated versus untreated cells. Migration assays were performed using 2x106 cells per well incubated with either 10µM acitretin or media, overnight in 1%FBS. Cells were subsequently transferred to chamber inserts overlying 10%FBS media containing 200ng/ml CXCL12 in all wells, except negative controls. Cells were allowed to migrate for 4hrs. Migration was calculated as percentage of cells in lower chamber to upper chamber.
Results
CD38 expression in MEC-1 cells was significantly upregulated in cells incubated with 10µM acitretin for 72 hours, (6.89 fold higher expression in acitretin treated cells compared to controls, n=3,**p=0.00075). In primary cells derived from patient samples that had CD38 expression ≥ 9% at baseline, acitretin produced an increase in CD38 expression that was 2.25 fold higher compared to untreated cells(n=5,* p=.022). However, in primary cells from patient samples with CD38 expression <9% at baseline, the effect of acitretin was only 1.53 higher CD38 expression in cells treated with 10µM acitretin at 72 hours. Significant modulation of CD38 expression in these cells was only achieved in the cells treated with 50µM acitretin for 72 hours (*p=.022).In cell migration, acitretin treatment resulted in a significant reduction in CLL cell homing toward CXCL12 in 14 out of 17 patient samples. Mean relative migration was reduced from 23.5% to 11.9% of input cells (11.6% reduction, **p=.00018, n=14, mean +/- SEM).These were cell samples from a varied group of patients that included 8(54%) from previously treated, relapsed patients and 6(43%) treatment naïve patient samples.
Conclusion
CD38 expression is significantly unregulated by acitretin in CLL cells expressing CD38 at baseline. We suggest this would prove advantageous in the setting of anti-CD38 monoclonal antibody therapy through improving efficacy of this drug, and should be studied further in CLL. Acitretin also reduced the homing ability of CLL cells towards the chemoattractant CXCL12, the mechanism and potential therapeutic implications of which needs to be further explored.
Session topic: E-poster
Keyword(s): CD38, Chronic lymphocytic leukemia, Retinoic acid
Type: Eposter Presentation
Background
CD38 expression is a robust prognostic indicator in Chronic Lymphocytic Leukemia(CLL) and has gained importance among the repertoire of markers utilised to aid management decisions in CLL. The CD38 molecule is also attracting interest as a mark for targeted therapies, namely anti-CD38 monoclonal antibody treatment. Retinoids modulate CD38 expression due to the presence of the Retinoic Acid Response Element (RARE) DNA sequence in intron 1 of the CD38 gene. Several studies have investigated this effect in myeloid malignancies however little is known about retinoid effect on lymphoid malignancies.
Aims
In this study we demonstrate that the retinoic acid derivative, acitretin, upregulates the expression of CD38 on the MEC-1 cell line and on primary CLL cells from CD38 positive patients. We propose that by doing so, acitretin may render these cells more susceptible to the actions of anti CD38 monoclonal antibody drugs and thus have a potential role as an adjunct to such therapies. We also show that acitretin reduces CLL cell homing in response to the chemokine CXCL12, therefore potentially preventing cells from reaching the micro environment niche and may as a result, lead to shortened survival.
Methods
Ethical approval for the study was obtained from the ethical committee in Beaumont University Hospital. Peripheral blood samples were collected from 32 patients with a confirmed diagnosis of CLL and who had given written informed consent. MEC-1 cells were obtained from DSMZ, Germany. MEC-1 cells and cells from five CD38 negative and five CD38 positive patients were treated with 10µM acitretin for 24 and 72 hours. CD38 expression was measured by flow cytometric analysis at baseline and at the different time points. Results are expressed as fold difference in Mean Fluorescence Intensity (MFI) in treated versus untreated cells. Migration assays were performed using 2x106 cells per well incubated with either 10µM acitretin or media, overnight in 1%FBS. Cells were subsequently transferred to chamber inserts overlying 10%FBS media containing 200ng/ml CXCL12 in all wells, except negative controls. Cells were allowed to migrate for 4hrs. Migration was calculated as percentage of cells in lower chamber to upper chamber.
Results
CD38 expression in MEC-1 cells was significantly upregulated in cells incubated with 10µM acitretin for 72 hours, (6.89 fold higher expression in acitretin treated cells compared to controls, n=3,**p=0.00075). In primary cells derived from patient samples that had CD38 expression ≥ 9% at baseline, acitretin produced an increase in CD38 expression that was 2.25 fold higher compared to untreated cells(n=5,* p=.022). However, in primary cells from patient samples with CD38 expression <9% at baseline, the effect of acitretin was only 1.53 higher CD38 expression in cells treated with 10µM acitretin at 72 hours. Significant modulation of CD38 expression in these cells was only achieved in the cells treated with 50µM acitretin for 72 hours (*p=.022).In cell migration, acitretin treatment resulted in a significant reduction in CLL cell homing toward CXCL12 in 14 out of 17 patient samples. Mean relative migration was reduced from 23.5% to 11.9% of input cells (11.6% reduction, **p=.00018, n=14, mean +/- SEM).These were cell samples from a varied group of patients that included 8(54%) from previously treated, relapsed patients and 6(43%) treatment naïve patient samples.
Conclusion
CD38 expression is significantly unregulated by acitretin in CLL cells expressing CD38 at baseline. We suggest this would prove advantageous in the setting of anti-CD38 monoclonal antibody therapy through improving efficacy of this drug, and should be studied further in CLL. Acitretin also reduced the homing ability of CLL cells towards the chemoattractant CXCL12, the mechanism and potential therapeutic implications of which needs to be further explored.
Session topic: E-poster
Keyword(s): CD38, Chronic lymphocytic leukemia, Retinoic acid
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