A novel cDNA transcript expressed in fractionated X-irradiation-induced murine thymomas.
Elucidation of the leukemogenic process induced by fractionated X-irradiation (FX) requires the identification of molecules that mediate the differentiation and regeneration of T cells. To isolate cDNA transcripts associated with FX-induced leukemia in C57BL/6 mice, a cDNA library was constructed from FX-induced thymoma mRNA and differentially screened with cDNA probes. A novel cDNA transcript, FX-induced transcript 1 (FXI-T1), showed strong differential mRNA expression in all C57BL/6 FX-induced thymomas examined when compared with normal thymus tissue. FXI-T1 was not universally expressed in proliferative or other neoplastic cells. Expression of FXI-T1 mRNA in untreated mouse organs was not restricted to the thymus; highest expression was observed in brain and skeletal muscle tissue. The translated FXI-T1 sequence encodes a basic, prolinerich protein that contains a RING-H2-finger motif. The COOH-terminal region of the putative FXI-T1 protein has sequence similarity with the COOH-terminal domain of the Drosophila deltex protein, a component of a signal pathway that functions during cell differentiation. The described observations suggest an association of FXI-T1 with FX-induced leukemogenesis. The study of FXI-T1 should contribute to an understanding of the processes of T-cell differentiation and regeneration in addition to leukemogenesis.
Pampeno
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CL
Department of Pathology, New York University Medical Center, New York 10016, USA. pampeco1@mcrcr.med.nyu.edu
Meruelo
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D015723:Gene Library; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009381:Neoplasms, Radiation-Induced; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013945:Thymoma / Q000209:etiology / Q000235:genetics*; D014018:Tissue Distribution / Q000235:genetics; D044767:Ubiquitin-Protein Ligases; D014916:Whole-Body Irradiation
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; C104035:Dtx1 protein, mouse; D044767:Ubiquitin-Protein Ligases