Ornithine decarboxylase (ODC) activity is elevated in and necessary for oral carcinogenesis, but the mechanism for its deregulation is unclear. Using subtractive hybridization, a 1029 bp full-length cDNA encoding a 222 amino acid open reading frame has been isolated from normal hamster oral keratinocytes. The hamster cDNA is homologous to the human, mouse and rat ornithine decarboxylase antizyme gene (ODC-Az). The hamster ODC-Az gene demonstrated a restriction fragment length polymorphism (RFLP) upon Southern blot analysis comparing normal and tumor hamster genomic DNA. Northern blot analysis revealed that normal hamster oral keratinocytes express readily detectable level of ODC-Az mRNA. Malignant oral keratinocytes demonstrate reduced expression of the ODC-Az mRNA. In contrast, malignant hamster oral keratinocytes have elevated ODC mRNA levels and lengthened ODC protein halflife when compared to the normal counterparts. This was corroborated by direct measurement of ODC enzymatic activity. These data support the hypothesis that the reduced and/or loss of expression and function of the ODC-Az gene is an important event for the early de-regulation of cellular proliferation during oral tumor development.
The infiltration of eosinophils into tissues during pathologic responses is often associated with extracellular matrix alterations such as fibrosis. Transforming growth factor-beta 1 (TGF-beta 1) is a well-characterized multifunctional cytokine known to exert potent effects on the extracellular matrix. In this report, we showed the production of TGF-beta 1 by human eosinophils from patients with blood eosinophilia. Northern blot analysis using RNA isolated from eosinophils purified from a patient with the idiopathic hypereosinophilic syndrome (HES) detected the 2.5-kb TGF-beta 1 transcript. In situ hybridization and immunohistochemistry of leukocytes from two patients with HES and two patients with blood eosinophilia localized TGF-beta 1 messenger RNA (mRNA) and protein to eosinophils. No other cell type contained TGF-beta 1 mRNA by in situ hybridization, whereas other leukocytes contained detectable TGF-beta 1 protein by immunohistochemistry. Eosinophils from four normal donors contained little or no detectable TGF-beta 1 protein by immunohistochemistry, whereas eosinophils from two of these four normal donors labeled weakly for TGF-beta 1 mRNA by in situ hybridization. These results show that eosinophils in the peripheral blood of patients with blood eosinophilia can express TGF-beta 1, but that eosinophils in the blood of normal donors contained little or no TGF-beta 1.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.