Suppression of apoptosis by bcl-2 overexpression in lymphoid cells of transgenic zebrafish.
The zebrafish is an attractive vertebrate model for genetic studies of development, apoptosis, and cancer. Here we describe a transgenic zebrafish line in which T- and B-lymphoid cells express a fusion transgene that encodes the zebrafish bcl-2 protein fused to the enhanced green fluorescence protein (EGFP). Targeting EGFP-bcl-2 to the developing thymocytes of transgenic fish resulted in a 2.5-fold increase in thymocyte numbers and a 1.8-fold increase in GFP-labeled B cells in the kidney marrow. Fluorescent microscopic analysis of living rag2-EGFP-bcl-2 transgenic fish showed that their thymocytes were resistant to irradiation- and dexamethasone-induced apoptosis, when compared with control rag2-GFP transgenic zebrafish. To test the ability of bcl-2 to block irradiation-induced apoptosis in malignant cells, we compared the responsiveness of Myc-induced leukemias with and without EGFP-bcl-2 expression in living transgenic zebrafish. T-cell leukemias induced by the rag2-EGFP-Myc transgene were ablated by irradiation, whereas leukemias in double transgenic fish expressing both Myc and EGFP-bcl-2 were resistant to irradiation-induced apoptotic cell death. The forward genetic capacity of the zebrafish model system and the ability to monitor GFP-positive thymocytes in vivo make this an ideal transgenic line for modifier screens designed to identify genetic mutations or small molecules that modify bcl-2-mediated antiapoptotic pathways.
Langenau
David M
DM
Department of Pediatric Oncology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA 02115, USA.
Jette
Cicely
C
Berghmans
Stephane
S
Palomero
Teresa
T
Kanki
John P
JP
Kutok
Jeffery L
JL
Look
A Thomas
AT
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology* / Q000528:radiation effects; D001402:B-Lymphocytes / Q000166:cytology / Q000502:physiology*; D017124:Conserved Sequence; D003907:Dexamethasone / Q000494:pharmacology; D015870:Gene Expression / Q000502:physiology / Q000528:radiation effects; D005938:Glucocorticoids / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics; D015458:Leukemia, T-Cell / Q000503:physiopathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics* / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*; D013950:Thymus Gland / Q000166:cytology; D015027:Zebrafish
D005938:Glucocorticoids; D019253:Proto-Oncogene Proteins c-bcl-2; D016271:Proto-Oncogene Proteins c-myc; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D003907:Dexamethasone