Search PubMed⌕ Search

Biomedical subjects

D W Kufe

Publications and source records attributed to D W Kufe.

At least 145 records · Page 8Linked to original sources
PubMed1988

Effect of radioiodination on the binding of monoclonal antibody DF3 to breast carcinoma cells.

The murine monoclonal antibody (MAb) designated DF3 is an IgG1 prepared against a membrane enriched fraction of human breast carcinoma. MAb DF3 reacts with a family of large molecular weight glycoproteins expressed by 78% of breast cancer cells and 95% of epithelial ovarian cancer cells. Binding to the breast cancer cell line, MCF-7, of native MAb DF3 was compared to that of MAb DF3 exposed to different concentrations of Iodogen or Bolton-Hunter reagent. The amount of MAb DF3 required to obtain half-maximal binding (B1/2max) with MCF-7 extract for native MAb DF3 IgG was 180 ng, while the B1/2max for MAb DF3 IgG exposed to 1 and 10 micrograms Iodogen was 580 ng and 1800 mg, respectively. In contrast, the B1/2max for MAb DF3 IgG treated with Bolton-Hunter reagent was not different from that for native MAb DF3 IgG. Similar results were obtained with F(ab')2. Immunoreactive fractions for the 125I-labeled MAb DF3 were 0.13, 0.24 and 0.65 for IgG after exposure to 1 microgram Iodogen, 10 micrograms Iodogen and Bolton-Hunter, respectively. Immunoreactive fractions for F(ab')2 were 0.08, 0.08, and 0.53 for 1 and 10 micrograms Iodogen and Bolton-Hunter reagent, respectively. Association constants (Ka) were significantly higher for MAb DF3 IgG radioiodinated with Bolton-Hunter (3.97 +/- 0.38 x 10(8) M-1) than for IgG exposed to 1 microgram Iodogen (2.78 +/- 0.30 x 10(8) M-1) or 10 micrograms Iodogen (1.03 +/- 0.12 x 10(8) M-1). Similarly, the Ka ratio observed for the F(ab')2 radioiodinated with Bolton-Hunter reagent, 1 or 10 micrograms Iodogen was 22 to 3 to 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1988

Tumor necrosis factor expression in human epithelial tumor cell lines.

Tumor necrosis factor (TNF) is a monokine with in vitro cytotoxicity for some but not all tumor cells. The basis for sensitivity and resistance to the antitumor effects of this agent remains unclear. The present studies have monitored the effects of TNF on 14 epithelial tumor cell lines. Eleven of these cell lines were resistant to the growth inhibitory effects of TNF (50% inhibitory concentration greater than 1,000 U/ml). 12 of the 14 tumor cell lines has detectable levels of high affinity cell surface TNF binding sites, thus suggesting that resistance was not often due to the absence of cell surface TNF receptors. Northern blot analysis demonstrated that three of the eleven resistant cell lines expressed detectable levels of TNF mRNA. Furthermore, both sensitive and resistant epithelial tumor cells had the capacity to express TNF transcripts in the presence of the protein synthesis inhibitor, cycloheximide. Finally, the presence of TNF expression at the RNA level is shown to be associated with the production of a TNF-like protein in the resistant Ov-D ovarian carcinoma cells. These findings suggest that certain human epithelial tumor cell lines inherently resistant to TNF also express this cytokine.

Animals↗
PubMed1988

Expression of platelet-derived growth factor (PDGF)-related transcripts and synthesis of biologically active PDGF-like proteins by human malignant epithelial cell lines.

Human malignant epithelial cell lines were analyzed for expression of platelet-derived growth factor (PDGF) genes. Of the 12 cell lines tested, 9, derived from breast, lung, gastric, and ovarian carcinomas, were found to express both PDGF-1 and PDGF-2 genes. The levels of both PDGF-1 and PDGF-2 transcripts were superinduced when these cells were treated with cycloheximide, an inhibitor of protein synthesis. These cells also released an activity that in studies with BALB-c/3T3 cells, inhibited binding of 125I-labeled PDGF and stimulated incorporation of [3H]thymidine. This stimulating activity was inhibited after reduction of the conditioned media by mercaptoethanol or after preincubation with antibodies to PDGF. Moreover, this activity was not affected by heat treatment. Immunoprecipitation studies revealed that breast, lung, and gastric carcinoma cells produced PDGF-like proteins that migrated as 30- and 32-kD species under nonreducing conditions and as 15- and 16-kD species under reducing conditions. In contrast, malignant cells of ovarian origin produced 14-16-kD PDGF-like proteins that were unchanged in mobility after reduction. As PDGF receptors were not detected on these malignant epithelial cells, the production of PDGF-like proteins may affect other cells in the microenvironment by paracrine mechanisms and may contribute to excessive cell proliferation, inflammatory reactions, and connective tissue remodeling seen in certain carcinomas.

Binding, Competitive↗
PubMed1988

Recombinant human tumor necrosis factor administered as a five-day continuous infusion in cancer patients: phase I toxicity and effects on lipid metabolism.

Recombinant human tumor necrosis factor (rH-TNF) is a cytotoxic monokine with pleiotropic effects. A phase I trial of rH-TNF was initiated using a five-day continuous intravenous (IV) infusion repeated every 28 days. Thirty-eight courses of therapy were administered to 19 patients. The starting dose was 5 X 10(4) U/m2/d, with escalations to 1.0 X 10(5), 2.0 X 10(5), 2.4 X 10(5), and 3.0 X 10(5) U/m2/d. Systemic side effects, including fever, chills, hypotension, fatigue, anorexia, and headaches, were mild and self-limiting. At the maximum tolerated dose of 3.0 X 10(5) U/m2/d, dose-limiting hematologic toxicity was manifested by transient thrombocytopenia and leukopenia. Elevated bilirubin levels were also seen at the higher dose levels. Lipoprotein analysis demonstrated that the five-day treatment with rH-TNF was associated with decreases in high-density lipoproteins, as well as increases in triglycerides and very-low-density lipoproteins. Pharmacokinetic studies using an enzyme-linked immunosorbent assay (ELISA) test indicated plasma rH-TNF levels less than 0.2 U/mL. The recommended phase II dose of rH-TNF administered as a five-day continuous infusion is 2.4 X 10(5) U/m2/d.

Chemical and Drug Induced Liver Injury↗
PubMed1988

Bryostatin 1 activates protein kinase C and induces monocytic differentiation of HL-60 cells.

Phorbol esters induce the human HL-60 promyelocytic cell line to differentiate along a monocytic pathway. This induction of differentiation may involve phorbol ester-induced activation of the phospholipid- and calcium-dependent protein kinase C. Bryostatin 1, a macrocyclic lactone, has been shown to compete with phorbol esters for binding to protein kinase C. We have confirmed that bryostatin 1 translocates activity of protein kinase C from the cytosolic to membrane fractions of HL-60 cells. The present results also demonstrate that bryostatin 1 (10 nmol/L) induces monocytic differentiation of HL-60 cells as determined by adherence, growth inhibition, appearance of monocyte cell surface antigens, and alpha-naphthyl acetate esterase staining. Furthermore, bryostatin 1 (10 nmol/L) downregulated c-myc expression and induced c-fos, c-fms, and tumor necrosis factor transcripts. These changes in gene expression induced by bryostatin 1 are similar to those associated with phorbol ester-induced monocytic differentiation of HL-60 cells. In contrast, exposure to a higher concentration of bryostatin 1 (100 nmol/L) had less of an effect on growth inhibition of HL-60 cells and changes in gene expression. Moreover, 100 nmol/L bryostatin 1 antagonized the cytostatic effects and adherence induced by phorbol esters. Our results thus suggest that bryostatin 1 activates HL-60 cell protein kinase C and that this effect is associated with induction of monocytic differentiation.

Bryostatins↗
PubMed1988

Phospholipase C activates protein kinase C and induces monocytic differentiation of HL-60 cells.

Phospholipase C (PLC)-mediated hydrolysis of membrane phospholipids results in the production of diacylglycerol, inositol phosphates, and choline metabolites. Inositol triphosphate increases calcium levels, while diacylglycerol activates protein kinase C. The present studies demonstrate that exogenous PLC generates inositol phosphates, releases choline metabolites, and activates protein kinase C in human HL-60 promyelocytic leukemia cells. PLC also induced monocytic differentiation of HL-60 cells as manifested by adherence, growth inhibition, and appearance of monocytic cell surface antigens. Furthermore, PLC treatment decreased c-myc mRNA levels and induced c-fos, c-fms, and tumor necrosis factor transcripts. The changes in gene expression induced by PLC are similar to those previously shown to be associated with phorbol ester-induced monocytic differentiation of HL-60 cells. Our results thus demonstrate that exogenous PLC activates HL-60 cell protein kinase C and that this effect is associated with induction of monocytic differentiation. PLC may therefore play a role in transducing signals from physiological inducers of monocytic differentiation.

Cell Differentiation↗
PubMed1988

c-sis but not c-fos gene expression is lineage specific in human myeloid cells.

Expression of both the c-fos and c-sis protooncogenes during myeloid differentiation has been detected in cells of the monocytic lineage. Since an increase in c-fos transcripts was not detected during dimethylsulfoxide induced HL-60 granulocytic differentiation, it was suggested that within the myeloid series c-fos gene expression might be lineage specific. In the present study, we have determined whether expression of the c-fos and c-sis genes is indeed specific for the monocytic pathway or rather common to both the granulocyte and monocyte pathways. C-fos and c-sis gene expression was analyzed in freshly isolated human granulocytes and monocytes, in human HL-60 promyelocytic leukemia cells induced to differentiate along the granulocytic or monocytic pathway, in myeloblasts from five patients with the M1 or M2 subtype of acute myeloblastic leukemia (AML) and in blasts from six patients with M4 myelomonocytic leukemia. The level of c-fos mRNA was fifteen times higher in granulocytes as compared with monocytes. An increase in c-fos expression was also found in HL-60 cells differentiated along the granulocytic pathway after exposure to hypoxanthine, hexamethylene bisacetamide, and the combination of retinoic acid and dibutyryl adenosine 3'5' cyclic monophosphate. Three of 5 M1 and M2 leukemic myeloblast preparations depleted of lymphoid and monocytic cells and all six M4 leukemic cells expressed c-fos transcripts. In contrast, c-sis gene transcripts were detectable in monocytes and during drug induced monocytic differentiation of the HL-60 cells but not in granulocytes during granulocytic differentiation of the HL-60 cells or in AML samples. Thus, in the myeloid series, c-sis gene expression is lineage specific while expression of the c-fos gene is found in both lineages and may be related to metabolic pathways common to both granulocytes and monocytes.

Actins↗
PubMed1988

Genetically determined polymorphism of the circulating human breast cancer-associated DF3 antigen.

The murine monoclonal antibody (MAb) DF3 was prepared against a human breast carcinoma. Previous studies have demonstrated that DF3 antigen levels are elevated in plasma of patients with breast cancer. Furthermore, MAb DF3 reacts with circulating glycoproteins of different molecular weights ranging from approximately 300 to 450 kd. The present study demonstrates that plasma DF3 antigen is comprised of at least four moieties with slow (S), intermediate (I), rapid (R) and very rapid (VR) electrophoretic mobilities. The electrophoretic mobility patterns for circulating DF3 antigen differ among individuals. Moreover, DF3 antigen is detectable in urine, and the electrophoretic mobility of the urinary moieties is similar, but not identical, to that in the plasma. Studies in family members suggest that the electrophoretic heterogeneity of plasma DF3 antigen is determined by codominant expression of multiple alleles at a single locus. This locus may code for the core protein of DF3 antigen. These findings thus identify a genetically determined polymorphism of a circulating tumor-associated glycoprotein.

Antibodies, Monoclonal↗
PubMed1987

Identification of a family of high molecular weight tumor-associated glycoproteins.

The monoclonal antibody (MAb) designated DF3 was prepared against a human breast carcinoma metastatic to liver. This MAb reacts with a high molecular weight glycoprotein detectable in human breast carcinomas and human milk. In contrast, MAb F36/22 was prepared against the MCF-7 breast carcinoma cell line, MAb 115-D8 against human milk fat globule membrane (HMFGM) and MAb Ca1 against the HEp-2 human laryngeal carcinoma cell line. These MAb have similar patterns of reactivity with normal tissues and tumors based upon immunoperoxidase staining. In the present study we have monitored reactivity of these MAb against DF3 antigen purified from human breast carcinoma cell lines (MCF-7, BT-20) and HMFGM. Solid phase immunoassays and immunoblotting demonstrate that MAb DF3, F36/22, 115-D8, and Ca1 all react with the same purified DF3 antigen. Furthermore, immunoblot analysis indicates that the DF3 antigen reactive with these MAb differs structurally in preparations from breast carcinoma cells and HMFGM. We also demonstrate that MAb F36/22 completely inhibits MAb DF3 binding in competitive blocking assays. In contrast, the results indicate that MAb 115-D8 and Ca1 only partially block MAb DF3 reactivity and the extent of this inhibition varies with DF3 antigen purified from breast carcinoma cells and HMFGM. Taken together, these findings with multiple MAb prepared against a variety of immunogens suggest that existence of a family of related but not identical high molecular weight tumor-associated glycoproteins.

Antibodies, Monoclonal↗
PubMed1987

Effects of interferon-gamma on proto-oncogene expression during induction of human monocytic differentiation.

Activation of the proto-oncogenes c-fos, c-fms, and c-sis has been associated with monocytic differentiation. In the present study, we monitored the relationship of c-myc, c-fos, c-fms, and c-sis expression to interferon-gamma (IFN-gamma)-induced monocytic differentiation of human HL-60 promyelocytic leukemia cells. Treatment of HL-60 cells with 500 U/ml IFN-gamma arrested cell proliferation after 3 days. Appearance of the monocytic phenotype was manifested within 24 hr of IFN-gamma exposure by: increased nitroblue tetrazolium reduction; increased cell surface expression of the HLA-DR, Mo1, and MY4 antigens; and induction of transcripts for the second component of complement (C2) and tumor necrosis factor. In contrast, c-myc expression decreased as a later event after 72 hr of IFN-gamma exposure, and c-fos transcripts remained undetectable until 5 days of treatment. Furthermore, c-fms RNA and transcripts for the macrophage marker apolipoprotein E were induced only after 7 days. Finally, expression of the c-sis proto-oncogene at the RNA and protein levels remained undetectable after induction with IFN-gamma. These findings would thus suggest that declines in c-myc RNA, as well as induction of c-fos, c-fms, and c-sis expression, are not requisite events in the commitment of HL-60 cells to IFN-gamma-induced monocytic differentiation. Expression of c-fos and c-fms, however, is associated with acquisition of markers associated with maturation to macrophages.

Antigens, Surface↗
PubMed1987

Clinical studies with tumour necrosis factor.

The mechanism of tumour necrosis factor (TNF) cytotoxicity remains unknown. The in vivo antitumour effects of TNF may be related to direct cytotoxicity, immunomodulatory effects or endothelial effects on tumour vasculature. Phase I and early Phase II clinical trials of human recombinant TNF are under way in Japan, the USA, the UK and Germany. The maximum Phase II dose for TNF has not been established. The clinical toxicity of TNF is generally similar to that of other biological agents. Systemic toxicity, including fever, chills, anorexia and nausea, has been seen in most patients treated with TNF and has not been clearly related to dose. Other toxicities have included liver function abnormalities, hypotension, transient neurological changes and haematological abnormalities. Few clinical responses have been reported but organized Phase II testing remains to be completed. Combination trials with interferons have recently been initiated. Phase II efficacy studies of TNF as a single agent and in combination are needed for an assessment of the value of this agent in cancer therapy.

Chemical and Drug Induced Liver Injury↗
PubMed1987

Induction of tumor necrosis factor expression and resistance in a human breast tumor cell line.

Tumor necrosis factor (TNF) is a polypeptide cytokine that is cytotoxic to some but not all tumor cells. The basis for resistance to the cytotoxic effects of this agent remains unclear. We have studied the development of TNF resistance in human ZR-75-1 breast carcinoma cells. ZR-75-1 cells have undetectable levels of TNF RNA and protein. However, TNF transcripts are transiently induced in these cells by exposure to recombinant human TNF. This induction of TNF RNA is associated with production of TNF-like protein in cell lysates and culture supernatants. Stable resistance to TNF-induced cytotoxicity develops when ZR-75-1 cells are exposed to increased concentrations of TNF. The TNF-resistant cells, designated ZR-75-1R, continuously express TNF transcripts and a TNF-like protein. Furthermore, ZR-75-1R cell supernatants contain cytotoxic activity that is abrogated by polyclonal antibody against TNF. The ZR-75-1R cells also possess TNF receptors that are occupied or down-regulated by the TNF-like protein. These findings thus suggest that (i) TNF induces TNF transcripts and production of a TNF-like protein in ZR-75-1 cells and (ii) resistance to TNF-induced cytotoxicity is associated with stable TNF expression.

Breast Neoplasms↗
PubMed1987

Southern blot analysis of BII cell line--a putative variant of HL-60.

Southern blot analysis of various genes was used to compare the human promyelocytic leukemia cell line HL-60 and the BII cell line, which reportedly arose as a spontaneous differentiation inducer-resistant variant from an HL-60 culture. Granulocyte-macrophage colony stimulating factor gene restriction fragment polymorphism, due to a partial deletion of one of the alleles of this gene in HL-60, was not observed in the BII cells. Furthermore, the p53 oncogene, most of which is deleted in the HL-60 cell line, was found to be intact in the BII cell line. Human leukocyte antigen typing revealed that the two cell lines shared the A locus but differed at the B locus. Several unique restriction fragments hybridizing to human leukocyte antigen class I and DR beta gene probes were observed in the DNA digests of each cell line. Altogether these data provide definitive evidence that BII represents a human cell line of different origin than HL-60. Further lineage determination of this cell line could add a useful member to the group of leukemic cell lines.

Antigens, Neoplasm↗
PubMed1987

Expression of tumor-associated antigen (DF3) in atypical hyperplasias and in situ carcinomas of the human breast.

The monoclonal antibody (MoAb) DF3 prepared against a membrane-enriched fraction of human breast carcinoma has previously shown a differential reactivity to cytoplasmic antigen in carcinomas versus antigen concentrated on apical borders in benign lesions of the breast. In the present report the cytoplasmic reactivity of MoAb DF3 within a spectrum of benign and malignant breast lesions was studied to define whether the DF3 antigen is expressed in the cytoplasm of potentially premalignant lesions, i.e., atypical hyperplasias, or early malignant lesions, i.e., in situ carcinomas. Biopsy specimens of breast lesions from 108 women, including 28 patients with invasive carcinoma, 12 with in situ carcinoma, 17 with atypical hyperplasia, 25 with proliferative lesions without atypia, and 26 with nonproliferative lesions, were examined for DF3 antigen expression with the use of an indirect immunohistochemical method. Atypical hyperplasias were less reactive with MoAb DF3 than invasive carcinomas (P = .05 by Wilcoxon rank sum test). No significant statistical differences were observed, however, between invasive carcinomas and in situ carcinomas or between in situ carcinomas and atypical hyperplasias on the basis of cytoplasmic DF3 reactivity. Invasive carcinomas, in situ carcinomas, and atypical hyperplasias, however, demonstrated significantly higher reactivity with MoAb DF3 in the cytoplasm than proliferative lesions without atypia and nonproliferative lesions (P less than .01). These studies demonstrate that atypical hyperplasias express elevated levels of a given tumor-associated antigen and thus provide further immunologic evidence that these lesions are premalignant.

Antibodies, Monoclonal↗
PubMed1986

Effects of cis-diamminedichloroplatinum on DNA incorporation and cytotoxicity of 1-beta-D-arabinofuranosylcytosine.

1-beta-D-Arabinofuranosylcytosine (ara-C) incorporates into replicating cellular DNA and the extent of this incorporation correlates with loss of clonogenic survival. More recent findings have demonstrated that incorporation of ara-C into DNA undergoing repair of damage induced by u.v. light also results in cell lethality. On the basis of previous studies demonstrating a marked synergism between cis-diamminedichloroplatinum (CDDP) and ara-C in LoVo colon carcinoma cells, the present work has examined the interaction of these agents at a biochemical and cellular level in the MCF-7 human breast carcinoma line. The extent of ara-C incorporation into MCF-7 DNA correlated significantly with loss of clonogenic survival in a dose-dependent manner. The effects of CDDP on the formation of MCF-7 (ara-C)DNA were monitored using both cesium sulfate and cesium chloride density centrifugation. The results demonstrate that CDDP had little, if any, detectable effect on incorporation of ara-C into DNA. Furthermore, combinations of CDDP and low concentrations of ara-C (10(-7) and 10(-6) M) decreased MCF-7 clonogenic survival in an additive but not synergistic manner. Modest synergy was detectable with CDDP and higher ara-C concentrations (10(-5) and 10(-4) M). The interaction between CDDP and ara-C was apparently dependent on concentration, duration of exposure and cell type. There was no dramatic synergy between CDDP and ara-C in MCF-7 cells. These findings may be relevant to the design and interpretation of CDDP/ara-C clinical trials.

Breast Neoplasms↗
PubMed1986

Effects of 5-fluorouracil on globin mRNA synthesis in murine erythroleukemia cells.

Although 5-fluorouracil (FUra) incorporates in all species of RNA, the molecular basis for producing cytotoxicity by RNA-related mechanisms remains unclear. We have studied the effects of FUra on the synthesis of alpha- and beta-globin mRNA in murine erythroleukemia cells. An analysis of equivalent amounts of RNA from FUra-treated cells suggested that this agent causes a relative increase in globin mRNA. However, when RNA obtained from the same number of cells was analyzed, thus taking into account decreases in ribosomal RNA, the amount of intracellular alpha- or beta-globin mRNA actually decreased following FUra treatment. The decrease in globin mRNA was associated with decreases in both intracellular globin and hemoglobin content. The findings thus indicate that FUra inhibits the accumulation of alpha- and beta-globin transcripts. This effect of FUra could occur by decreasing transcriptional rate or, as in the case of ribosomal RNA, by interfering with the processing of these nucleic acids. Either mechanism could contribute to the RNA-related cytotoxicity induced by this agent.

Animals↗