cis-diamminedichloroplatinum(II) cross-linking of the human myeloid cell nuclear differentiation antigen to DNA in HL-60 cells following 1,25-dihydroxy vitamin D3-induced monocyte differentiation.

Protein-DNA interactions of the human myeloid cell nuclear differentiation antigen (MNDA) were examined in vivo in proliferating HL-60 promyelocytic leukemia cells and following induction of differentiation by 1,25-dehydroxyvitamin D3. Intact cells were treated with the reversible cross-linking agent cis-diamminedichloroplatinum(II) and the MNDA levels in the isolated protein-DNA complexes were determined. Less than 1% of the total intracellular level of MNDA was cross-linked to DNA in the noninduced proliferating HL-60 cells. Once the cells were induced to differentiate into monocytes, the amount of antigen cross-linked to the DNA increased to over 5% of the total intracellular level. The increased efficiency of cross-linking the MNDA to DNA was specific for monocyte-induced HL-60 differentiation, achieved with three inducers, and was not observed in association with granulocyte-induced differentiation. On a molar basis the phorbol ester (12-O-tetradecanoylphorbol-13-acetate) was the most effective inducer of monocyte differentiation, followed by 1,25-dihydroxy-16-ene-23-ynecholecalciferol which was more effective than 1,25-dihydroxycholecalciferol. A cesium chloride gradient analysis of the nucleic acid-protein fraction isolation from cis-diamminedichloroplatinum(II)-treated, monocyte-induced HL-60 cells documented the authenticity of the association between the MNDA and DNA. The results indicate that a significant level of chromatin reorganization may accompany monocyte-induced differentiation that leads to much higher levels of MNDA-DNA cross-linking to DNA. The expression of the MNDA is restricted to human myeloid cells and the present results indicate that a fraction of this low abundance nuclear protein is specifically located near the DNA [within cis-diamminedichloroplatinum(II) cross-linking distance] and that this association may be modulated specifically during monocyte differentiation.

Molecular characterization of non-histone chromatin proteins from experimental tumours.

Using two-dimensional (2-D) electrophoresis, two non-histone chromatin protein fractions (NHCP1 and NHCP2) from three animal tumours (Kirkman-Robbins hepatoma, Morris hepatoma 7777 and Ehrlich ascites cells) and normal hamster liver were analyzed. Apart from many common components several tissue specific polypeptides of the NHCP1 and NHCP2 fractions were detected. It was found that some spots present in electropherograms of non-histone proteins of tumour cells (M X 10(-3)/pI): 17-24/4.9-6.5 (NHCP1 and NHCP2); 34-41/4.9-6.0 (HCP1 and NHCP2); 44-46/5.3-7.5 (HCP2); 46-49/5.0-7.5 (NHCP1); 49/5.9-7.5 (NHCP2) and 102-134/5.6-7.0 (NHCP1) were absent from normal liver.

Tightly complexed with DNA nonhistone chromatin proteins from hamster Kirkman-Robbins hepatoma.

Two groups of nonhistone chromatin proteins tightly bound to DNA were isolated from hamster liver and Kirkman-Robbins hepatoma with the use of hydroxyapatite columns: 1. NP proteins which can be briefly defined as nonhistone chromatin proteins, nondissociable from DNA in 5 M urea, and 2. a group of proteins nondissociable in 2 M KCl and thus believed to be nonelectrostatically bound to DNA. The proteins were characterized by their amino acid analysis, SDS-polyacrylamide gel electrophoresis and their influence on template activity of DNA. Some differences in electrophoretic patterns and template activity inhibition were found between the latter group of proteins from liver and hepatoma.

Specificity of non-histone proteins from hamster Kirkman-Robbins hepatoma.

Nuclear phosphoproteins from Syrian hamster liver and Kirkman-Robbins hepatoma were obtained by phenol method of TENG et al. and their chemical composition was investigated. Amino acid composition of phosphoproteins from both tissues resembled each other to a great extent. There was almost twice more phosphorus in the preparations from hepatoma than in the ones from liver. Using two electrophoretic techniques: SDS-polyacrylamide gel electrophoresis and isoelectric focusing some differences between the examined proteins of neoplastic and normal tissue were found. Three additional fractions (molecular weights 29 000, 89 000 and 93 000, respectively) could be observed in case of hepatoma proteins in comparison with the ones from liver. The phosphoproteins of Kirkman-Robbins hepatoma revealed three additional bands with isoelectric points 6.6, and 7.1.

A note on the use of protease inhibitors during chromatin fractionation on hydroxyapatite columns.

It was found that NaHSO3 present in the eluents enabled full and reproducible recovery of chromosomal proteins from a hydroxyapatite column. Another protease inhibitor, PMSF, did not have that effect.

Nuclear glycoproteins of hamster liver and Kirkman-Robbins hepatoma recognized by concanavalin A.

1. Glycoproteins recognized by Concanavalin A (ConA) have been identified in nuclei and nuclear fractions differing in sensitivity to micrococcal nuclease digestion from hamster liver and Kirkman-Robbins hepatoma. 2. The major ConA binding proteins from hamster liver and Kirkman-Robbins hepatoma nuclei have molecular weights about 27,000 and 57,000, and 38,000 and 49,000, respectively. 3. A distinct distribution of glycoproteins between fractions differing in sensitivity to nuclease digestion has not been observed.

Lectin-binding glycoproteins in nuclear fractions from hamster liver and Kirkman-Robbins hepatoma.

As a further step toward characterizing the major nuclear glycoproteins from hamster liver and Kirkman-Robbins hepatoma (Lipinska A. and Gaczynski M. Int. J. Biochem. 4, 1385-1390, 1992) its intranuclear localization was studied. The glycoprotein patterns of examined nuclear fractions of hamster liver and hepatoma revealed some cell specificity observed especially in nuclear matrix preparations. Our results show the extensive presence of envelope glycoproteins in the nuclear matrix.

Growth-related changes of non-histone chromatin proteins from Kirkman-Robbins hepatoma.

1. Non-histone chromatin protein fractions NHCP1 and NHCP2 eluted from hydroxyapatite with 50 and 100 mM phosphate buffer (pH 6.8) from nuclei of Kirkman-Robbins hepatoma from 4th, 7th and 9th day of growth were analysed by one- and two-dimensional gel electrophoresis as well as Western blot technique in the presence of antibodies elicited against NHCP1, NHCP2 and dehistonized chromatin of hamster hepatoma and liver. 2. The presence of electrophoretically and immunologically specific components among NHCP1 and NHCP2 fractions during Kirkman-Robbins hepatoma growth was stated.

Nuclear distribution pattern of tumour-associated nonhistone protein of mol. wt 48,000.

1. As a further step toward characterizing nonhistone protein of mol. wt 48,000 which was found to be much more abundant in animal tumour cells than in normal ones [Krajewska W.M., Lipínska A., Marszatek M., Kilianska Z., Wojtkowiak Z. and Klyszejko-Stefanowicz L. Cell. Biochem. Funct. 8, 79-89 (1990)] its intranuclear localization in hamster liver and Kirkman-Robbins hepatoma was studied. The protein was identified by immunoblotting technique in the presence of antibodies against polypeptide of mol. wt about 48,000 from Kirkman-Robbins hepatoma. 2. Distribution of antigen with mol. wt of 48,000 in nuclear fractions representing different levels of nuclear material organization, i.e. in nucleoli, nuclease-sensitive and nuclease-resistant fractions, and extensive nuclease digestion products separated by size on Bio-Gel A-50m; implied the structural role of this component. 3. Fractionation of endogenously digested nuclei into low salt extract, high salt extract and nuclear matrix revealed that in normal liver the antigen studied is associated with nuclear matrix while in hepatoma this component appeared in high salt extract. 4. These results suggest that polypeptide with mol. wt of 48,000 is a shuttling protein which may be involved in reorganization of nuclear matrix during neoplastic transformation.

Nuclear antigen with a molecular weight of 48,000 associated with malignant transformation.

1. Analysis of immunoblots of one- and two-dimensional electropherograms of non-histone proteins from Kirkman-Robbins hepatoma, Morris hepatoma 7777, regenerating liver and normal liver demonstrated the presence of elevated level of nuclear antigen with mol. wt of 48,000 and pI of 5.4 in tumour cells. 2. Small amounts only were detected in proliferating and quiescent cells suggesting that different expression of this component may reflect biochemical events related to malignant transformation rather than to general cell activation.

Nuclear proteins of hamster hepatoma after administration of antitumour agents.

One- and two-dimensional gel electrophoretic analysis of nuclear proteins of Kirkman-Robbins hepatoma was used to study the effects of the tumour growth inhibitors methotrexate (MTX) and acyclonucleoside (DHPQtB) on protein composition. MTX and DHPQtB inhibited Kirkman-Robbins hepatoma growth by 89.2 +/- 3.5% and 16.3 +/- 6.1% respectively. The biosynthesis and/or metabolism of some polypeptide spots was affected by these antitumour agents, especially among components with molecular wt/isoelectric points of 52,000-64,000/4.9-5.5, 69,000-78,000/5.0-5.9 and 88,000-100,000/5.1-5.9.

Intranuclear distribution of the human myeloid cell nuclear differentiation antigen in HL-60 cells.

Based on solubility properties, the human myeloid cell nuclear differentiation antigen exists as at least two distinct populations. Most is easily extracted from isolated nuclei in 0.35 M NaCl, while 20 percent resists such treatment. Compared to undigested nuclei, both the amount of myeloid cell nuclear differentiation antigen (MNDA) released from nuclei after DNase I treatment and the amount resisting further extraction in 0.35 M NaCl increased after DNA was digested with DNase I. Under these conditions, there was a concomitant decrease in the amount of MNDA that was extractable with 0.35 M NaCl. Mixing nuclear protein extracts that contain MNDA with nuclei from cells that do not express this protein demonstrated that the MNDA redistributes from the freely soluble form to the nuclear residual fraction as a consequence of DNase I digestion. These data are consistent with a model in which the amount of MNDA that is tightly bound to salt-washed nuclei is held constant in the presence of an excess of unassociated MNDA in the nucleus, and that the level of MNDA binding to this nuclear fraction increases in proportion to the extent of DNA damage resulting from DNase I digestion.

Thioacetamide-stimulated expression of non-histone protein.

The search for cancer specific nuclear proteins, stimulated by the supposition that transition from the normal to the neoplastic state resulting from disturbances in the control mechanisms of gene expression, indicated that non-histone protein of MW 48 kD is much more abundant in animal tumour cells than in normal liver (Krajewska et al., 1990). A non-histone component of MW 48 kD was assessed for changes during chemically induced carcinogenesis. Rats were treated with the hepatocarcinogen thioacetamide (TAA) and the expression of the polypeptide studied, in total nuclear protein and nonhistone protein fractions, was tested by Western blot technique in the presence of antibodies developed against a component of MW 48 kD from Kirkman-Robbins hepatoma. It was demonstrated that TAA-induced hepatocarcinogenesis was accompanied by the expression of non-histone protein of MW 48 kD at a significantly elevated level. A clear and distinct change in the expression of the component studied in the spleen of TAA-treated rats was also observed. These results support the suggestion that over-expression of non-histone protein of MW 48 kD could contribute to neoplastic transformation.