Identification of differentially expressed genes in T-lymphoid malignancies in an animal model system.
The molecular events characterizing lymphoid malignancy have been examined in an animal model system, specifically, the retroviral induction of leukemia and lymphoma in the domestic cat following infection with feline leukemia virus (FeLV). Genes differentially expressed in FeLV-induced lymphomas were isolated using a strategy of differential hybridization. Six genes were identified which demonstrate a higher level of expression in an FeLV-induced feline thymic tumor as compared with normal thymus. The differentially expressed genes encode the feline homologues of ribosomal proteins S3a, S4, S17, and L41, elongation factor-1 alpha, and cytochrome oxidase sub-unit I. Northern-blot analysis and quantification by phosphorimaging demonstrates that these genes are expressed at levels from 1.5- to 3.1-fold higher in J5-1 thymic tumor as compared with normal thymus. Expression of the selected ribosomal protein mRNA was further examined in a series of human and feline tissues, including normal tissues, malignant tumors and cell lines. Our data reveal that elevation of the selected ribosomal protein mRNA is associated with all FeLV-induced thymic lymphomas examined. The differentially expressed ribosomal protein mRNA accumulates in a balanced manner in thymic lymphomas. By contrast, the elevation in ribosomal protein mRNA levels is not associated uniformly with hematopoietic malignancy. T-lymphoid malignancy, solid tumors or actively proliferating cells. Rather, the elevation appears to be a uniform and distinctive feature of T-cell malignancy of this particular type. The elevated expression of these genes may be causally related to the neoplastic process.
Starkey
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Program in Molecular and Cellular Biology, Tulane Medical School, New Orleans, LA, USA.
Levy
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D000328:Adult; D000818:Animals; D015152:Blotting, Northern; D002415:Cats; D004273:DNA, Neoplasm / Q000032:analysis / Q000235:genetics; D004195:Disease Models, Animal; D003576:Electron Transport Complex IV / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D005256:Leukemia Virus, Feline; D015458:Leukemia, T-Cell / Q000235:genetics* / Q000821:virology; D016399:Lymphoma, T-Cell / Q000235:genetics* / Q000821:virology; D008297:Male; D009857:Oncogenes; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D012269:Ribosomal Proteins / Q000235:genetics; D013953:Thymus Neoplasms / Q000235:genetics*; D014407:Tumor Cells, Cultured
D004273:DNA, Neoplasm; D020648:Peptide Elongation Factor 1; D010445:Peptide Elongation Factors; D012333:RNA, Messenger; D012269:Ribosomal Proteins; D003576:Electron Transport Complex IV