Presentation Title

Effects of Paclitaxel on Glucocorticoid-induced apoptosis of Human Leukemic CEM Cells

Faculty Mentor

Rheem D. Medh

Start Date

18-11-2017 2:15 PM

End Date

18-11-2017 3:15 PM

Location

BSC-Ursa Minor 46

Session

Poster 3

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

Glucocorticoids (GCs) are steroid hormones widely used in anti-leukemia therapy as they can induce apoptosis through gene-regulatory pathways that affect pro- and anti-apoptotic genes. In cell culture models of human acute lymphoblastic leukemia (ALL), the synthetic GC, Dexamethasone (Dex), has induced expression of pro-apoptotic genes including E4BP4 (a transcription factor that upregulates pro-apoptotic BIM) and apoptotic regulators, such as FOXO3 and BIRC3, in correlation with apoptosis. Paclitaxel (Ptx), a taxol-derived anti-proliferative alkaloid often used with Dex in anti-leukemia therapy, induces apoptosis via a distinct but overlapping transcriptional response. In this study we investigate the effects of Ptx alone, and in combination with Dex, on pro- and anti-apoptotic genes to understand the molecular implications of the combined treatment. The CCRF-CEM cell lines CEM-C7-14 and CEM-C1-15 were previously found to be sensitive and resistant, respectively, to Dex. Sensitivity to Dex was restored in CEM-C1-15 cells upon ectopic expression of mouse E4BP4 (line CEM-C1-15mE#3). We are also testing the hypothesis that E4BP4 and BIM play central roles in regulating Ptx-induced apoptosis, and that combined treatment synergistically triggers apoptosis by greater magnitude of upregulation, while activating a broader spectrum of pro-apoptotic pathways. The cell lines were treated with Dex and Ptx, alone and in combination, for 24h. Relative gene expression in response to treatments was evaluated by reverse transcription and end-point PCR, followed by ImageJ analysis. Staining cells with Annexin V-FITC, followed by epifluorescence microscopy, confirmed apoptosis. Our data suggest that Ptx upregulated FOXO3, BIRC3, and BIM, but down-regulated E4BP4 in the CEM-C7-14 cells.

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Nov 18th, 2:15 PM Nov 18th, 3:15 PM

Effects of Paclitaxel on Glucocorticoid-induced apoptosis of Human Leukemic CEM Cells

BSC-Ursa Minor 46

Glucocorticoids (GCs) are steroid hormones widely used in anti-leukemia therapy as they can induce apoptosis through gene-regulatory pathways that affect pro- and anti-apoptotic genes. In cell culture models of human acute lymphoblastic leukemia (ALL), the synthetic GC, Dexamethasone (Dex), has induced expression of pro-apoptotic genes including E4BP4 (a transcription factor that upregulates pro-apoptotic BIM) and apoptotic regulators, such as FOXO3 and BIRC3, in correlation with apoptosis. Paclitaxel (Ptx), a taxol-derived anti-proliferative alkaloid often used with Dex in anti-leukemia therapy, induces apoptosis via a distinct but overlapping transcriptional response. In this study we investigate the effects of Ptx alone, and in combination with Dex, on pro- and anti-apoptotic genes to understand the molecular implications of the combined treatment. The CCRF-CEM cell lines CEM-C7-14 and CEM-C1-15 were previously found to be sensitive and resistant, respectively, to Dex. Sensitivity to Dex was restored in CEM-C1-15 cells upon ectopic expression of mouse E4BP4 (line CEM-C1-15mE#3). We are also testing the hypothesis that E4BP4 and BIM play central roles in regulating Ptx-induced apoptosis, and that combined treatment synergistically triggers apoptosis by greater magnitude of upregulation, while activating a broader spectrum of pro-apoptotic pathways. The cell lines were treated with Dex and Ptx, alone and in combination, for 24h. Relative gene expression in response to treatments was evaluated by reverse transcription and end-point PCR, followed by ImageJ analysis. Staining cells with Annexin V-FITC, followed by epifluorescence microscopy, confirmed apoptosis. Our data suggest that Ptx upregulated FOXO3, BIRC3, and BIM, but down-regulated E4BP4 in the CEM-C7-14 cells.