RESUMO
We analyzed protein expression of cyclin D1, cyclin D2, and cyclin D3 using high-resolution enzymatic amplification staining and flow cytometry in the neoplastic cells from 80 patients with CD5+ B-cell lymphoproliferative disorders. The D cyclins were expressed differentially in chronic lymphocytic leukemia (CLL), prolymphocytic leukemia (PLL), and mantle cell lymphoma (MCL) with strong staining of cyclin D1 and D2 in MCL, strong staining of cyclin D1 but weak staining of cyclin D2 in 4 of 5 PLLs, and low-level staining for both cyclins in most CLLs. No correlation between cyclin D1 and D2 and growth rates or CD38 expression was observed. However, cyclin D1 levels were significantly higher in ZAP-70+ CLL cases, although no association between ZAP-70 and cyclin D2 was detected. The results indicate that flow cytometric analysis of D cyclins may help in classification of CD5+ B-cell lymphoproliferative disorders.
Assuntos
Antígenos CD5/análise , Ciclina D1/análise , Ciclinas/análise , Leucemia Linfocítica Crônica de Células B/classificação , Leucemia Prolinfocítica/classificação , Linfoma de Célula do Manto/classificação , Proteína-Tirosina Quinase ZAP-70/análise , ADP-Ribosil Ciclase 1/análise , Proliferação de Células , Ciclina D2 , Citometria de Fluxo , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Prolinfocítica/metabolismo , Linfoma de Célula do Manto/química , Fosfatidilinositol 3-Quinases/fisiologiaRESUMO
BACKGROUND: D cyclins are essential for the progression of cells through the G1 phase of the cell cycle. There are three distinct D cyclins. Cyclin D1 has been shown to be expressed by many different types of cells but not by lymphocytes. Cyclins D2 and D3 have been found in lymphocytes. METHODS: We used high-resolution enzymatic amplification staining technology in conjunction with flow cytometry and confocal microscopy and with immunoblotting to reassess the expression of the D cyclins in human lymphocytes. RESULTS: Using high-resolution technology for flow cytometry, we found all three D cyclins in quiescent human peripheral blood lymphocytes. Cyclin D1 was expressed in quiescent and activated cells at levels commensurate with those of actively proliferating tumor cell lines. Cyclin D1 was functional inasmuch as it was complexed with CDK4. In the quiescent cells, cyclin D1 was expressed in the cytoplasm but, after activation, was found in the nucleus. CONCLUSIONS: These findings demonstrate that lymphocytes express cyclin D1 and necessitate a reappraisal of the hypothesis that the D cyclins subsume redundant activities with tissue-specific expression.
Assuntos
Ciclinas/metabolismo , Linfócitos/metabolismo , Linhagem Celular , Quinase 4 Dependente de Ciclina , Quinases Ciclina-Dependentes/metabolismo , Citometria de Fluxo , Humanos , Immunoblotting , Imuno-Histoquímica , Ativação Linfocitária , Proteínas Proto-Oncogênicas/metabolismo , Coloração e RotulagemRESUMO
Flow cytometric analysis of human platelets from healthy volunteers by high-resolution immunophenotyping accomplished with enzymatic amplification staining revealed the expression of CD34. Assessment of the platelets with five different monoclonal antibodies to the three different classes of CD34 epitopes suggested that platelets express a unique glycoform of the molecule. Expression of CD34 was verified by immunoblotting. Platelet activation resulted in a marked decrease in surface CD34. CD34 expression has significant implications for the function of platelets as well as for the determination of hematopoietic progenitor cells.
