The present study was undertaken to provide more information on the heterochromatin density in central and peripheral nuclear regions during "cell dedifferentiation" represented by blastic transformation of mature T lymphocytes. Heterochromatin was visualized using a simple cytochemical method for the demonstration of DNA followed by computer-assisted densitometry of digitised images. The results indicated that the blastic transformation was accompanied by a marked and significant decrease in the heterochromatin density at the nuclear membrane. Thus, this nuclear peripheral region seems to be important not only for cell differentiation but also dedifferentiation events. It is also interesting that the non-stimulated resting mature cells in the present study were characterized by less condensed heterochromatin at the nuclear membrane than differentiated granulocytic or erythrocytic precursors and apoptotic myeloblasts or leukemic B lymphocytes described in the previous study. However, in contrast to these cells, resting and mature T lymphocytes in the present study are known to revert to cycling blastic cells after PHA treatment. In addition, it is also known that nuclear peripheral regions with heterochromatin represent sites of chromosomal attachments as well as “together crowded replicons“ and silent genes.
Heterochromatin density; lymphocytes; blastic transformation
Astaldi G, Lisiewicz J: Lymphocytes. Idelson, Naples 1971.
Boyum A: Separation of leukocytes from blood and bone marrow. Scand J Clin Lab Invest 21:9-109, 1968.
Busch H, Smetana K: The Nucleolus. Academic Press, New York 1970.
Carson DA: Biochemistry and function of lymphocytes and plasma cells. In Williams WJ, Beutler E, Erslev AJ, Lichtman MA (eds.): Hematology, McGraw-Hill, New York 1983, pp. 903-908.
Cline MJ: The White Cell. Harvard University Press, Cambridge 1975.
Comings DE: Arrangement of chromatin in the nucleus. Hum Genet 53:131-143, 1980.
Cremer T, Cremer C: Rise, fall and resurrection of chromosome territories: a historical perspective. Part III. Chromosome territories and the functional nuclear architecture: experiments and models from the 1990s to the present. Eur J Histochem 50:223-272, 2006.
Frenster JH: Ultrastructure and function of heterochromatin and euchromatin. In Busch H (ed): The Cell Nucleus, Academic Press, New York 1974, pp. 565-581.
Grygoryev SA, Bulynko YA, Popova EY: The end adjusts the means: heterochromatin p remodeling during terminal cell differentiation. Chromosome Res 14:53-69, 2006.
Hoffbrand AV, Pettit JE: Clinical Haematology. Gower Medical Publishing, London 1988.
Kalousek I, Krizkova P: Lymphocyte mitogenic transformation is accompanied by phosphorylation of the nucleolar transcription factor UBF. Cell Mol Biol (Noisy-le-grand), 46:1163-1171, 2000.
Monge JM, Val-Bernal JF, Buelta L, Garcia- Castrillo L, Asensio L: Selective nuclear morphometry as prognostic factor of survival of renal carcinoma. Histol Histopathol 14:119-123, 1999.
Nowell PC: Differentiation of human leukaemic leukocytes in tissue culture. Exp Cell Res 19:267-277, 1960.
Ochs RL: Methods used to study structure and function of the nucleolus. Methods Cell Biol 53:303-321, 1998.
Pederson T: The spatial organization of the genome in mammalian cells. Curr Opin Genet Dev 14:203-209, 2004.
Politi EN, Lazaris AC, Kavantzas A, Kountselini H: Comparison between morphometry and immunostaining of malignant cells in no-small cell lung cancer. Anal Quant Cytol Histol 25:169-176, 2003.
Rubin AD: Ribosome synthesis in cultured lymphocytes. II. The role of ribosomal RNA production in the initiation and maintenance of lymphocyte growth. Blood 35:708-720, 1970.
Setala L, Lipponen P, Kosma VM, Marin S, Eskelinen M, Syrjanen K, Alhava E: Nuclear morphometry as predictor of disease outcome in gastric cancer. J Pathol 181:46-50, 1977.
Schnedl W, Schnedl M: Nucleluszahl und grosse wahrend des Zellzyklus. Z Zellforsch 126:374-382, 1972.
Smetana K: Nucleoli in maturing blood cells. Top Rev Haematol 1:115-137, 1980.
Smetana K, Lejnar J, Potmesil M: A note to the demonstration of DNA in nuclei of blood cells in smear preparations. Folia Haematol 88:305-317, 1967.
Smetana K, Lejnar J, Potmesil M: A further contribution to the demonstration of RNA and nucleoli of blood cells in smear preparations. Folia Haematol 91:381-384, 1969.
Smetana K, Klamova H, Hrkal Z: To the density and distribution of condensed chromatin in differentiating maturing and apoptic cells represented by granulocytic, lymphoblastic and erythroblastic precursors in human bone marrow biopsies (a cytological study). Folia Biol (Prague) 2007, in press.
Zhimulev IF: Heterochromatin, gene position effect and gene silencing. Genetika 39:187-201, 2003.
Smetana K, Mikulenkova D, Klamova H. Heterochromatin Density (Condensation) During Cell Differentiation and Maturation Using the Human Granulocytic Lineage of Chronic Myeloid Leukaemia as a Convenient Model. Folia Biol. 57: 216-221, 2011.
Smetana K, Karhan J, Trneny M. Heterochromatin condensation in central and peripheral nuclear regions of maturing lymphocytes in the peripheral blood of patients suffering from B chronic lymphocytic leukemia - a cytochemical study. Neoplasma. 58: 476-481, 2011.
Smetana K, Otevrelova P, Jiraskova I, Kalousek I. On the nucleolar and cytoplasmic RNA density during "cell dedifferentiation" represented by blastic transformation of human mature T lymphocytes - A cytochemical study. Folia Histochem Cytobiol. 46: 429-432, 2008.