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A Lichtenstein

Publications and source records attributed to A Lichtenstein.

At least 19 recordsLinked to original sources
PubMed1992

Effects of beta-2 microglobulin anti-sense oligonucleotides on sensitivity of HER2/neu oncogene-expressing and nonexpressing target cells to lymphocyte-mediated lysis.

The mechanism by which HER2/neu overexpressing tumor cells resist NK, LAK, and LDCC cytotoxic lymphocytes was investigated. Resistance was not explained by a delay in kinetics of lysis, concurrent resistance to TNF, or a diminished expression of the transferrin receptor. HLA-class I expression, however, was markedly elevated compared to HER2 nonexpressing targets suggesting a reason for resistance. To test the role of class I, we selectively decreased expression by incubation of targets with beta-2 microglobulin anti-sense oligonucleotides. Anti-sense-treated HER2+ targets, displaying levels of class I comparable to HER2- targets, were still markedly resistant to cytotoxic effectors. Down-regulation of class I expression in HER2- carcinoma cells also had no effect on sensitivity to cytotoxicity by anti-sense treatment of Raji and U937 targets resulted in enhanced sensitivity to NK and LAK effectors but not to T cells mediating LDCC. These data indicate resistance to cytotoxicity in HER2-expressing targets cannot be solely explained by heightened expression of class I. The data also support the concept that class I expression regulates sensitivity to NK and LAK cells (but not LDCC effectors) in selected targets.

Animals↗
PubMed1992

Interferon-induced increase in sensitivity of ovarian cancer targets to lysis by lymphokine-activated killer cells: selective effects on HER2/neu-overexpressing cells.

Overexpression of the HER2/neu oncogene in ovarian tumor cells is associated with relative resistance to lymphokine-activated killer (LAK) cell cytotoxicity. Treatment with gamma-interferon (IFN-gamma) (200-2000 units/ml) for 3 days markedly enhanced the sensitivity of HER2/neu-overexpressing ovarian tumor cells to LAK cells but had no effect on the sensitivity of nonexpressing ovarian targets. Increased sensitivity to lysis was associated with an increase in effector-target conjugate formation, the induction of target cell intercellular adhesion molecule 1 (ICAM-1) expression, and the down-regulation of HER2/neu expression. Anti-ICAM-1 antibody blocked the enhanced lysis, indicating that ICAM-1 is important in the increased sensitivity to LAK cells. However, induction of ICAM-1 expression did not correlate well with enhanced sensitivity to lysis; it was maximal after 24 h of exposure to IFN-gamma and still present 24 h after removing IFN-gamma. In contrast, enhanced lysis required 3 days of exposure to IFN-gamma and was reversed within 24 h after removal of IFN-gamma. These data indicate that, although ICAM-1 is necessary, it is not sufficient for the IFN-gamma-induced enhancement of sensitivity to LAK lysis.

Cell Line↗
PubMed1991

Inhibitors of ADP-ribose polymerase decrease the resistance of HER2/neu-expressing cancer cells to the cytotoxic effects of tumor necrosis factor.

Four human ovarian and breast tumor lines expressing the HER2/neu oncogene were resistant to the cytotoxic and DNA-degradative activity of TNF. The resistance was not associated with altered TNF receptor function because Scatchard analysis of 125I-rTNF binding to HER2/neu-expressing target cells revealed receptors with normal binding parameters. Furthermore, the TNF receptors on the resistant lines were capable of signal transduction as evidence by the induction of ADP-ribose polymerase activity and MHC expression. TNF resistance was not reversed by coincubation with drugs that interrupted the glutathione redox cycle. In addition, although coincubation of HER2/neu-expressing targets with cycloheximide resulted in significant TNF-induced lysis, when compared to HER2/neu-nonexpressing targets similarly treated with cycloheximide, a significant relative resistance was still present. To investigate the role of ADP-ribosylation in the resistance of these targets, we used nontoxic concentrations of two inhibitors of ADP-ribose polymerase, 3-aminobenzamide, and nicotinamide. Both inhibitors completely reversed the resistance of HER2/neu-expressing targets to TNF-mediated cytotoxicity and DNA injury in a concentration-dependent fashion. These inhibitors of ADP-ribose polymerase did not act by down-regulating expression of HER2/neu oncogenes. In contrast, aminobenzamide and nicotinamide significantly diminished TNF-induced cytotoxicity of L929 targets. These data suggest that the activity of ADP-ribose polymerase may play a pivotal role in determining the fate of the target cell during exposure to TNF.

Cytotoxicity, Immunologic↗
PubMed1991

Human neutrophil peptide defensins induce single strand DNA breaks in target cells.

To investigate whether target cell DNA injury participates in cytolysis by human neutrophil defensins (HNP), we analyzed HNP-treated cells for single strand breaks by the alkaline unwinding assay and the activation of ADPribose polymerase, a DNA repair enzyme. Strand breaks and ADP-ribosylation were first detected in K562 and Raji targets 6-8 hr after incubation with HNP and increased to maximal levels by 18 hr. DNA was not degraded into nucleosome-sized fragments. To assess the impact of DNA injury on cytolysis, we increased strand breakage by coincubating targets with HNP and two inhibitors of ADPribose polymerase, 3-aminobenzamide, or nicotinamide. Concurrently with inhibiting polymerase activity and increasing DNA injury, these agents significantly enhanced HNP-mediated cytolysis. Enhancement occurred only at time points (over 6 hr) and in targets (only nucleated targets) where HNP-induced DNA injury could be occurring. These data indicate that neutrophil defensins can induce DNA injury in targets and suggest such injury may be involved in target cell death.

Benzamides↗
PubMed1991

Mechanism of mammalian cell lysis mediated by peptide defensins. Evidence for an initial alteration of the plasma membrane.

Defensins induce ion channels in model lipid bilayers and permeabilize the membranes of Escherichia coli. We investigated whether similar membrane-active events occur during defensin-mediated cytolysis of tumor cells. Although defensin-treated K562 targets did not release chromium-labeled cytoplasmic components for 5-6 h, they experienced a rapid collapse (within minutes) of the membrane potential, efflux of rubidium, and influx of trypan blue. Defensin treatment also blunted the subsequent acidification response induced by nigericin, thereby further supporting the notion of enhanced transmembrane ion flow during exposure. These initial effects on the plasma membrane were not sufficient for subsequent lysis; a second phase of injury was required which involved the continued presence of defensin. The rapid membrane permeabilization phase was inhibited by azide/2-deoxyglucose, cytochalasin B, and increased concentrations of extracellular potassium and was unaffected by actinomycin-D, cycloheximide, and varying the calcium concentration. In contrast, the second phase was unaffected by cytochalasin B, inhibited by azide/2-deoxyglucose, enhanced by actinomycin D and cycloheximide, and varied with calcium concentration. These results indicate the initial adverse effect of defensins on mammalian cells occurs at the cell membrane. It is possible that the second phase of injury is mediated intracellularly by defensin that has been internalized through this leaky membrane.

Blood Proteins↗
PubMed1991

Hierarchical immunosuppression of regional lymph nodes in patients with head and neck squamous cell carcinoma.

Patients with head and neck squamous cell carcinomas (HNSCCs) manifest defects in cell-mediated immune function. Previous studies in this laboratory have demonstrated regional alterations in the immunocompetence of draining lymph nodes (LNs) in HNSCC patients. In this investigation, we studied functional activity of lymphocytes from lymph nodes in different locations in the radical neck dissections (RNDs) from patients undergoing operations for HNSCC. Lymphocytes from nodes close to the primary tumor ("near" lymph nodes or NLN) exhibited a significant decrease in interleukin-2 (IL-2)-activated cytotoxicity when compared to lymphocyts from distant nodes ("far" lymph nodes or FLN). In addition, co-culture experiments suggested the existence of a soluble regulatory factor, produced by lymph nodes, that inhibited the development of lymphokine-activated killer (LAK) cells in vitro. Further experiments with conditioned supernatants from the lymph node cells confirmed the presence of this soluble inhibitory factor. The inhibitory effect is significantly greater in NLNs than in FLNS. This hierarchical phenomenon suggests a regional network of immunosuppression in HNSCC patients. It is likely that tumor- and lymph node-induced suppression plays a role in limiting the efficacy of current immunotherapy protocols in human beings. A greater understanding of mechanisms of local inhibition of immune function will aid in improving adoptive immunotherapy for treatment of cancers in human beings.

Aged↗
PubMed1990

Resistance of human ovarian cancer cells to tumor necrosis factor and lymphokine-activated killer cells: correlation with expression of HER2/neu oncogenes.

Since overexpression of HER2/neu oncogenes in breast cancer cells is associated with resistance to the cytotoxic effect of tumor necrosis factor (TNF), we investigated whether this correlation also existed for ovarian cancer targets. Nine continuously cultured human ovarian cancer lines were studied and compared to 3 breast cancer lines. Three of the ovarian and 1 breast cancer line demonstrated amplified HER2/neu genes by Southern analysis, increased HER2/neu RNA by Northern analysis, and marked immunoperoxidase staining for HER2/neu protein. The other 8 lines contained unamplified genes and undetectable RNA and protein. All 4 overexpressed lines were relatively resistant to the cytotoxic effects of TNF. Interestingly, they were also resistant to lymphokine-activated killer cells. In contrast, 7 of 8 nonexpressed lines showed sensitivity to TNF and all 8 were sensitive to lymphokine-activated killer cells. There was no difference in sensitivity to lysis by hydrogen peroxide or peptide defensins between over- and nonexpressed lines. These data indicate that expression of HER2/neu oncogenes may impart a proliferative advantage in tumor cells due to induction of resistance to several different cytotoxic mechanisms.

Blotting, Northern↗
PubMed1990

Expression of shared idiotypes by paraproteins from patients with multiple myeloma and monoclonal gammopathy of undetermined significance.

Twenty-nine murine monoclonal antibodies have been produced that react with shared idiotypes expressed by B-cell lymphomas and leukemias. We tested this panel of antibodies for reactivity with the paraproteins from 32 patients with multiple myeloma and 10 patients with monoclonal gammopathy of undetermined significance (MGUS). Thirteen of 42 paraproteins reacted with at least one antibody in this panel of anti-idiotypic antibodies. Six different anti-idiotypes demonstrated reactivity with the paraproteins. A similar frequency of reactivity was found for both myeloma and MGUS proteins. One antibody, S30-47, reacted with 6 of 32 (19%) of the paraproteins from patients with multiple myeloma, whereas this anti-idiotype only bound to 3% of non-Hodgkin's B-cell lymphomas and no cases of chronic lymphocytic leukemia. This anti-idiotype reacted with both components of a biphenotypic paraprotein (IgG kappa and IgG lambda) in one patient. In each of nine patients tested, plasma cells isolated from bone marrow were shown to be reactive with the same anti-idiotype we found to react with the paraprotein. Antishared idiotype antibodies may provide useful reagents for studies of patients with monoclonal gammopathies.

B-Lymphocytes↗
PubMed1990

First place--Resident Clinical Science Award 1990. Suppression of lymphokine-activated killer cell cytotoxicity by a soluble factor produced by squamous tumors of the head and neck.

Incubation of human peripheral blood lymphocytes (PBL) in the presence of interleukin-2 results in the generation of lymphokine-activated killer (LAK) cells that are highly cytotoxic to a variety of autologous and allogenic tumor targets. We have identified a noncytotoxic, soluble factor, produced by human squamous cell cancers of the head and neck, that profoundly inhibits the generation of LAK cytotoxicity. Inhibition of the generation of cytotoxicity was demonstrated with coculture of PBL and freshly disaggregated tumor cells in a Transwell two-chamber system. Alternatively, inhibition occurred when LAK cells were generated in the presence of tumor-conditioned supernatants alone. These effects were not observed with conditioned supernatants from autologous or allogenic lymphocytes, human fibroblasts, or the erythroleukemia cell line K562. The presence of this inhibitory factor(s) was not required during the entire period of LAK generation. Suppression of cytotoxicity, measured after 4 days of LAK generation, could also be demonstrated when the conditioned tumor supernatant was present in only the last 24 hours of incubation. Suppression is mediated by a heat-labile factor with a molecular weight of greater than 75 kd. These results suggest that LAK cytotoxicity may be significantly impaired by soluble immunoregulatory factors present within the tumor milieu of squamous cell carcinomas of the head and neck. Further characterization of these factors may lead to the development of more rational and effective forms of immunotherapy.

Academies and Institutes↗
PubMed1990

Oncogenes in multiple myeloma: point mutation of N-ras.

Alterations of ras, c-myc and bcl-1 have been described in hematologic malignancies of lymphoid origin. We investigated the structure of these genes and evaluated the frequency of point mutations involving H-, K- or N-ras in bone marrow samples from patients with multiple myeloma. No abnormalities were detected in the c-myc and bcl-1 genes, but two of 17 patients were found to have N-ras mutations by differential oligonucleotide hybridization and dideoxynucleotide sequencing following amplification by polymerase chain reaction. Bone marrow DNA from both patients had identical missense mutations of N-ras codon 61 changing CAA to AAA, resulting in a substitution of lysine for glutamine in the encoded protein. Multiple myeloma is the first mature B cell neoplasm found to harbor ras mutations.

Base Sequence↗
PubMed1989

Human neutrophil-mediated lysis of ovarian cancer cells.

Because of recent questions concerning the sensitivity of human tumor cells to neutrophil-induced oxidative injury, we studied six freshly obtained human ovarian cancer (OC) specimens. Stimulation of neutrophils (PMNs) by phorbol myristate acetate (PMA) did not result in OC cytolysis during the first nine hours of incubation. However, three of six specimens were significantly lysed by stimulated PMNs when assay length was increased to 18 hours. Cytotoxicity was mediated by PMN production of reactive oxidative intermediates (ROIs). Presentation of ROIs to OC targets as preformed or enzymatically generated molecules in cell-free systems duplicated the enhanced lysis at 18 hours (as compared with six hours). Since addition of catalase at three or six hours did not inhibit enhanced lysis at 18 hours (achieved by PMNs or in cell-free systems), it appears that an initial ROI-mediated lethal event occurs early, but longer incubations are required for the event to become manifested as cell death. These data suggest that shorter assays may underestimate the potential of PMNs as effector cells against human tumor cells.

Adenocarcinoma↗
PubMed1989

Lymphokine-activated killing of autologous and allogeneic short-term cultured head and neck squamous carcinomas.

Interleukin-2-(IL-2)-activated lymphocytes have been shown to kill a variety of continuously cultured allogeneic (nonself), natural killer cell-sensitive and resistant cell lines, and some autologous (self) tumor cells. Lymphokine-activated killer (LAK) cytotoxicity of autologous head and neck squamous cell carcinoma (HNSCC) cells has not been previously demonstrated, and efforts to demonstrate this have been hampered by the lack of a reliable and reproducible method of obtaining satisfactory tumor targets. In this study, fresh tumor cells were enzymatically dissociated, enriched by adherence to plastic, and used in a 3-hour chromium-51 cytotoxicity assay. Peripheral blood lymphocytes (PBLs) were incubated for 3 days with or without added IL-2. IL-2-activated PBLs showed significant cytotoxicity against autologous and allogeneic targets, while only low levels of tumor lysis occurred with unstimulated PBLs. These findings suggest the possible use of IL-2-activated lymphocytes in the adoptive immunotherapy of HNSCC patients.

Carcinoma, Squamous Cell↗
PubMed1989

Production of cytokines by bone marrow cells obtained from patients with multiple myeloma.

Previous work with continuously cultured multiple myeloma lines suggested that cytokine production by tumor cells may mediate some of the medical complications of this disease. To further investigate this issue, we assayed freshly obtained bone marrow (BM) cells from myeloma patients for the in vitro production of cytokines and the presence of cytokine RNA. Production of cytokine protein was assessed by bioassays with the aid of specific neutralizing anticytokine antibodies. These assays detected interleukin-1 (IL-1) and tumor necrosis factor (TNF) secretion by myeloma BM cells, which was significantly greater than secretion from similarly processed BM cells of control individuals. In contrast, lymphotoxin and interleukin-2 (IL-2) production could not be detected. The levels of IL-1 and TNF produced in vitro peaked at 24 hours of culture and correlated with stage and the presence (or absence) of extensive osteolytic bone disease. Northern blot analysis demonstrated the presence of IL-1 beta and TNF RNA in uncultured myeloma BM cells but no detectable IL-1 alpha or lymphotoxin RNA. In addition, the amount of cytokine RNA correlated with protein production, being significantly greater in patients' BM cells than in control marrow. These data suggest a role for IL-1 beta and/or TNF in the pathophysiology of multiple myeloma and argue against a role for lymphotoxin or IL-2.

Aged↗
PubMed1989

Clonal rearrangement of the beta-T cell receptor gene in multiple myeloma.

Because clonal rearrangements of the beta-T cell receptor (beta-TCR) gene occur in some patients with B cell chronic lymphocytic leukemia, we studied the arrangement of this gene in fourteen patients with multiple myeloma, a malignancy of the most terminally differentiated B cells. The gene was in germline configuration in peripheral blood lymphocytes (PBLs) and bone marrow samples of thirteen patients. By contrast, it was clonally rearranged in the marrow but not in the PBLs of one patient with stage IIA IgA-lambda myeloma. This patient's bone marrow consisted of 95% morphologically identifiable plasma cells which were CALLA-, OKT10+ (93%), and PCA-1+ (78%). Only 5% of marrow cells were small lymphocytes which contained T cell markers (CD3+ or CD2+). To eliminate the possibility that the small percentage of contaminating T cells contained the gene rearrangement, they were depleted by avidin-biotin immunoadsorption using the Leu4 determinant. Positively selected marrow T cells did not contain beta-TCR gene rearrangements. By contrast, the T cell depleted marrow contained the rearranged gene. This is the first demonstration that rearranged beta-TCR genes can occur in multiple myeloma.

Blotting, Northern↗
PubMed1988

Intraperitoneal administration of human recombinant interferon-alpha in patients with ovarian cancer: effects on lymphocyte phenotype and cytotoxicity.

Eleven patients with persistent Stage III ovarian cancer, documented at second look laparotomy, received i.p. human recombinant interferon-alpha (5-50 x 10(6) units/week). Prior to immunotherapy, patients' peritoneal cell lymphocytes (PCLs) contained decreased proportions of Leu-7+ and Fc-receptor+ cells and almost nondetectable natural killer (NK) and antibody-dependent cell cytotoxic (ADCC) activity. In contrast, patients' peripheral blood lymphocytes (PBLs) contained normal proportions of lymphocyte subsets and cytotoxic activity compared to control donor PBLs. During therapy, there was a concurrent increase in PCL Leu-7+ cells and NK lysis. Both peaked predictably at 24 h after each treatment, regardless of the dose injected, and usually returned to baseline by Day 7 of each weekly cycle. PCL NK enhancement was striking, usually increasing from 2-6% (effector:target ratio, 25:1) to over 30% lysis. Enhancement of PCL ADCC was less impressive. PCLs of several patients developed lytic activity towards NK-resistant Raji targets. During therapy, patients' PBLs demonstrated: (a) modestly enhanced NK lysis at Day 4 of each cycle, and; (b) no development of Raji lysis. These data clearly demonstrate the efficacy of i.p. interferon in activation of peritoneal NK activity. However, increased NK lysis did not correlate with individual tumor responses in this cohort of patients.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1988

Neutrophil-mediated nonoxidative tumor lysis stimulated by high concentrations of phorbol myristate acetate.

The mechanism of neutrophil-mediated lysis of tumor targets was investigated. Tumor lysis was directly related to the concentration of phorbol myristate acetate (PMA) used to stimulate PMNs. Lysis increased as the PMA concentration increased between 10(-7) and 10(-4) M. In contrast, the production of H2O2 plateaued between concentrations of 10(-5) and 10(-4) M. The K562 erythroleukemia cell, the target used in this study, was found to be relatively resistant to preformed H2O2, with an LD50 of 8.3 X 10(-3) M. Myeloperoxidase was not capable of enhancing K562 lysis. Although resistant to preformed H2O2, K562 lysis mediated by PMNs stimulated with 10(-7) M PMA was oxidative in nature. It was sensitive to inhibition by catalase and was not significant when PMNs from patients with chronic granulomatous disease were used. In contrast, PMN lysis stimulated by 10(-4) M PMA was nonoxidative in nature. The inhibitors catalase and superoxide dismutase had no effect on lysis, lysis was significant when the assay was performed in an anaerobic atmosphere, and PMNs from patients with chronic granulomatous disease were comparable to control PMNs in tumor lysis. A single-cell conjugate and cytotoxicity assay demonstrated that PMA was both able to increase the ability of PMNs to bind to tumor targets and to enhance their lysis of bound targets. These data indicate that PMNs are capable of achieving tumor lysis by nonoxidative pathways under certain conditions. The high-dose PMA model may be valuable as a tool for investigating these alternative mechanisms of tumor lysis.

Anaerobiosis↗
PubMed1987

Stimulation of the respiratory burst of murine peritoneal inflammatory neutrophils by conjugation with tumor cells.

Murine peritoneal neutrophils (PMNs), elicited by i.p. injection of formalin-killed Corynebacteria parvum, spontaneously lyse teratocarcinoma targets through the secretion of reactive oxygen intermediates. Examination of effector-target interactions at the single cell level revealed that PMNs conjugated to tumor cells were 3-fold more frequently stained by nitroblue tetrazolium compared to nonconjugating PMNs suggesting that tumor targets stimulated a potent tumor-lytic respiratory burst. This notion was confirmed by the detection of superoxide and hydrogen peroxide generation from PMNs as well as a luminol-dependent chemiluminescent response following conjugation with viable tumor targets. Generation of superoxide was dependent upon the presence of dihydrocytochalasin B. In addition to teratocarcinoma cells, comparable stimulation was achieved by conjugation with YAC and P815 targets but not thymocytes. Reactive oxygen intermediate release was also achieved by mixing peritoneal PMNs with heat-killed tumor cells. In contrast to bacteria-induced effectors, PMNs elicited by i.p. injection of thioglycollate were incapable of responding following conjugation with tumor targets although they were competent for reactive oxygen intermediate release when stimulated by phorbol myristate acetate. Teratocarcinoma targets were sensitive to concentrations of H2O2 that could be achieved by PMNs following contact. These data indicate that Corynebacteria-elicited inflammatory PMNs lyse their bound tumor targets by a mechanism similar to a stimulus-secretion model.

Animals↗