Biomedical subjects
Publications and source records attributed to D Duś.
Some new substituted 5-amino-3-methyl-4-ureidoisoxazoles and the 4-ethyl urethane of the 5-amino-3-methyl-isoxazole have been synthesized from 5-amino-3-methyl-4-isoxazolecarboxylic acid azide. Some representative ureides with primary, secondary, and heterocyclic amines were tested for their antileucemic activity.
Human erythrocyte glycophorin was desialylated by mild acid hydrolysis and degalactosylated by Smith degradation. Two monoclonal antibodies (Tn5 and Tn56) obtained by immunization of mice with this 'artificial' Tn antigen were characterized and compared in some experiments with two antibodies (BRIC111 and LM225) obtained in other laboratories by immunization with Tn erythrocytes. The specific binding of the antibodies to glycophorins desialylated and degalactosylated on the nitrocellulose blot and to asialo-agalactoglycophorin-coated ELISA plates, and reactions with authentic Tn antigen served for identification of their anti-Tn specificity. The antibodies were further characterized in inhibition assay with various glycoproteins. The antibody Tn5 (similar to BRIC111) was shown to be specific for human erythrocyte Tn antigen, whereas Tn56 reacted strongly with different glycoproteins carrying O-linked GalNAc alpha- residues, and was strongly bound to the murine adenocarcinoma cell line Ta3-Ha. The antibodies Tn5, Tn56 and BRIC111 were similarly inhibited by ovine submaxillary mucin (OSM) and asialoOSM, but the antibody LM225 showed a distinct preference in reaction with OSM (sialosyl-Tn antigen). The results show that Tn antigen, obtained by chemical modifications of human glycophorin, enables the preparation and characterization of anti-Tn monoclonal antibodies, without using rare Tn erythrocytes.
Analysis of epitopes for the three monoclonal antibodies (GPA105, GPA33, OSK4-1) against glycophorin A (GPA) was performed with the use of proteolytic fragments of GPA, the synthetic nonapeptide with the sequence of amino acid residues 35-43 of GPA, and a series of peptides synthesized on plastic pins. The antibodies were specific for a short peptide sequence RAHE (a.a. 39-42 of GPA, MAbs GPA105 and OSK4-1) or RAHEV (a.a. 39-43 of GPA, MAb GPA33). Despite recognizing the same fragment of GPA, the three antibodies showed differences in fine specificity and in response to antigen desialylation. Reactions with single replacement analogs of the RAHEV sequence showed that immunodominant (unreplaceable) residues for the MAbs GPA33 and OSK4-1 were His and Glu, respectively, whereas no such residue was found for the MAb GPA105. Desialylation of the antigen gave strong enhancement of reactivity with the MAb GPA33, moderate--with the MAb GPA105, and weak or no enhancement of reaction with the MAb OSK4-1. The results showed that monoclonal antibodies directed against the same fragment of the polypeptide chain of densely glycosylated antigen may recognize different subsites which are masked at different degree by sialic acid residues.
The availability of neoplastic cell lines with well defined growth characteristics has greatly facilitated study of the tumor phenotype, tumor progression and metastatic process. MmB16 cell line has been established in vitro from the B16 mouse melanoma serially passaged in C57BL/6 mice. From MmB16 cells two lectin-resistant (LecR) variants were selected with the use of Aleuria aurantia agglutinin (AAA). The correlation between the lectin resistance and their in vivo growth parameters, especially tumorigenicity and metastatic ability, were evaluated. The local tumor growth and the average survival time of mice after subcutaneous (s.c.) inoculation of AAAR variant cells did not differ significantly from those of the parent MmB16 cells. However, the AAAR variants revealed significantly higher experimental lung colonizing ability after intravenous (i.v.) administration and slightly increased spontaneous metastatic ability after s.c. inoculation, as compared to parent MmB16 cells.
An observation was made that imuthiol exerts inhibitory effect on hemolysins forming cells (PFC) and on NK cells activity. It also reduces the number of T lymphocytes (in vitro), increases the activity of interleukin-1 and of the lymph node permeability factor. Well recognized is also its protective effect on thymocytes against hydrocortisone. Imuthiol was found to enhance rosette formation and to stimulate stem cells and partly suppressor cells. It reduces the level of cAMP. Its effect on the circulatory system is negligible.
Phosphonic acid and phosphinic acid analogues of tyrosine and 3,4-dihydroxyphenylalanine (dopa) were found to influence tyrosinase activity, thus being potential regulators of melanization in mammalian cells. The analogues were tested for their cytostatic activity in vitro, by means of total cell protein determination, on mouse B16 melanoma and, for comparison, on human KB carcinoma cell lines. Four compounds out of 22 revealed promising cytostatic activity for both cell lines, being nearly equipotent with dopa. Those compounds which most effectively suppressed the growth of both tumour cell lines were the same as those which had a significant influence on tyrosinase activity regardless of whether they acted as inhibitors or substrates.
It was found that a decrease in electrophoretic mobility of pyruvate kinase (PK) isoenzyme, and an increase of the sensitivity of this enzyme to L-cysteine, were markers of immortalization and tumorigenic properties, respectively, in human urothelial cell lines characterized by different grades of transformation (TGr) in vitro.
Cytostatic activity of newly synthesized aziridinyl substituted cyclophosphazenes was tested in two in vitro systems. First, the compounds were tested by total cell protein inhibition test on human KB tumor cell line. Selected active compounds were tested in a clonogenic assay on murine L1210 leukemia cells. Out of 18 compounds tested, 12 were newly synthesized, 3 were their substrates and 4 were compounds with known cytostatic activity, used as a positive controls. Four of the newly synthesized compounds, designated with symbols: BANF-4Az, BBNF-4Az. T-oFDA-Az and W-10 revealed cytostatic activity for KB cells (ED50 = 3.4-19 micrograms/mL) and were tested in clonogenic assay. One of these compounds, namely T-oFDA-Az was subsequently selected for the further steps of screening for antitumor activity in animal tumor models.
An investigation was undertaken to determine if an agglutinin isolated from Aleuria aurantia possesses a mitogenic activity. Proliferation response of mouse lymphoid cell cultures was measured by 3H-thymidine uptake. The results revealed that Aleuria aurantia agglutinin at the concentration of 1 microgram/ml is mitogenic for Thy-1+ splenocytes and cortisone-resistant thymocytes.
Total cellular glycopeptides of 7 human uroepithelial cell lines that differ in the grade of transformation (TGr) were analysed by gel filtration and affinity chromatography on immobilized lectins. The 4 cell lines that are tumorigenic in nude mice and invasive in vitro (TGr III) possess more highly branched, tri- and tetraantennary N-acetyllactosaminic glycans, with less biantennary glycans than the 2 non-tumorigenic, noninvasive (TGr II) cell lines examined. The only exception to this general pattern is the third cell line, which is classified as TGr II. The cellular glycopeptide distribution pattern in this cell line is similar to that of the TGr III cells. The possible relationship between altered glycosylation of membrane glycoproteins and the expression of a malignant phenotype is discussed.
The results of studies on the H-2 antigens expression on L1210 and P388 mouse lymphoma cells and their drug-resistant sublines as well as on Lewis lung carcinoma (LL2) cells and their wheat germ agglutinin-resistant variants (LL(2)5 and LL(2)8) are presented. The results revealed no qualitative alterations in H-2 antigens expression on cells of L1210 and P388 leukemias and their drug-resistant sublines. However, as determined by cytotoxic assay the increase relative to parental lines in the expression of normal H-2d antigens on cells of both drug-resistant sublines was observed. Using quantitative absorption assay in addition to differentiate quantitative expression of normal H-2b antigens, the presence of alien H-2k and H-2d specificities on lectin-resistant cells of Lewis lung carcinoma was detected.
Michaelis-Arbuzov reaction of N-(chloroacetyl)amino phosphonic acids or their esters, followed by acidolysis, gives moderate yields of N-(phosphonoacetyl) derivatives of a variety of (aminoalkyl)phosphonic acids, including analogues of the cytostatic agent PALA, in which the alpha- or beta-carboxylic groups in the aspartate moiety are replaced by a PO3H2 function. Assay of cytostatic activity with human KB cell lines indicates that the substitution of any of the COOH groups in PALA with PO3H2 results in total loss of cytostatic activity. No activity was observed also in the case of other [N-(phosphonoacetyl)amino]alkylphosphonic acids described in this report.
LL2 is a new in vitro cell line derived from Lewis lung carcinoma passaged routinely in C57BL mice. It has been in continuous culture for more than 1 year and has survived 72 subcultivations. The cells grow in semi-suspension culture being loosely connected with a culture vessel's surface. The cell line is hypotetraploid, with modal chromosome number 72. Tumorigenicity and metastasibility of the cells are retained but lowered as compared with original in vivo tumor line. The LL2 cell line is being used in studies on phenotypic characteristics (markers) related to its pattern of growth.
Cytostatic activity of 48 new amino acid analogs and derivatives of phosphonic acid type was tested against KB cell line in vitro. The tests were performed according to the recommended international protocol for screening of chemical agents against tissue culture system. Three of the compounds tested: No. No, 29, 33 and 32 revealed cytostatic activity at the concentrations: 63, 150, and 180 micrograms ml-1 respectively (ID50).
Among lectins from Lotus tetragonolobus, Ulex europaeus I and Evonymus europaea, agglutinating cells with blood group H determinants containing L-fucose alpha 1 leads to 2-linked to subterminal D-galactose, only the last lectin agglutinates thioglycolate- and paraffin oil-stimulated murine and guinea pig peritoneal exudate cells (PEC). The agglutination is inhibited by specific inhibitors of Evonymus lectin only: lacto-N-fucopentaose I and lactose. These results suggest the presence of a determinant on the surface of PEC, containing L-fucose alpha 1-linked at the nonreducing end which is different from blood group H determinants. Nonstimulated murine peritoneal cells (PC) are not agglutinated by the lectin but become agglutinable after neuraminidase treatment. Unstimulated guinea pig PC from different animals are agglutinated to a different extent by the same lectin concentration and show increased agglutinability after neuraminidase digestion. These results show that receptor for Evonymus lectin also exists on the nonstimulated PC but access to it is hindered by sialic acid. Trypsin- and pronase-digested PEC show increased agglutinability with Evonymus lectin. These results suggest that the lectin receptor is a glycolipid. Since alpha-linked L-fucose has been suggested as a part of the macrophage receptor for migration inhibitory factor in the guinea pig (Remold, J. Exp. Med. 1973. 138: 1065), the effect of Evonymus europaea lectin on the migration of PEC was studied. It was found that lectin inhibits the migration of PEC in the capillary tube assay up to 80%.
The MLC response of normal lymphocytes to different kinds of EBV-transformed LCL was investigated. The response to allogeneic LCL cells remarkably exceeded the response to xenogeneic and autologous LCL cells. Stimulation performed with EBV-transformed and normal cells obtained from the same donors showed a correlation in the reaction levels (Q = 0.434). This incomplete correlation was not improved by the reduction of the number of stimulating LCL cells. In MLC stimulated with LCL no statistically significant differences between responses to 2,1 or alloantigens were found.
TFX (Polfa) was tested for potential carcinogenic effect in in vitro and in in vivo - in vitro tests, using BALB/c mouse cells. Neither mouse embryo culture cells, nor BALB/3T3 fibroblasts cell line exposed to TFX did show any sign of transformation in their pattern of growth and morphology. In the in vivo - in vitro peritoneal macrophages transformation test TFX caused transformation as estimated by alteration in cell morphology and growth behavior, but after s.c. transplantation of the transformed cells into immunoincompetent syngeneic animals as well as into nude mouse, no tumor developed.
Cytostatic activity of 6 new cis-dichlorodiammineplatinum (II)--(DDP) derivatives were tested against human HeLa S3, Chang Liver and Lu-106 cell lines in vitro. The tests were performed according to the recommended international protecol for screening of synthetics in cell culture system. One of the tested compounds appeared to be more active than DDP, used as referential agent. The activity of the remained compounds was lower than DDP.