Intratumor administration of beta-interferon in recurrent malignant gliomas. A phase I clinical and laboratory study

The Dose Dependent Effects of Ruxolitinib on the Invasion and Tumorigenesis in Gliomas Cells via Inhibition of Interferon Gamma-Depended JAK/STAT Signaling Pathway

Objective

Glioblastoma multiforme (GBM) is the most aggressive for of brain tumor and treatment often fails due to the invasion of tumor cells into neighboring healthy brain tissues. Activation of the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is essential for normal cellular function including angiogenesis, and has been proposed to have a pivotal role in glioma invasion. This study aimed to determine the dose-dependent effects of ruxolitinib, an inhibitor of JAK, on the interferon (IFN)-I/IFN-α/IFN-β receptor/STAT and IFN-γ/IFN-γ receptor/STAT1 axes of the IFN-receptor-dependent JAK/STAT signaling pathway in glioblastoma invasion and tumorigenesis in U87 glioblastoma tumor spheroids.

Methods

We administered three different doses of ruxolitinib (50, 100, and 200 nM) to human U87 glioblastoma spheroids and analyzed the gene expression profiles of IFNs receptors from the JAK/STAT pathway. To evaluate activation of this pathway, we quantified the phosphorylation of JAK and STAT proteins using Western blotting.

Results

Quantitative real-time polymerase chain reaction analysis demonstrated that ruxolitinib led to upregulated of the IFN-α and IFN-γ while no change on the hypoxia-inducible factor-1α and vascular endothelial growth factor expression levels. Additionally, we showed that ruxolitinib inhibited phosphorylation of JAK/STAT proteins. The inhibition of IFNs dependent JAK/STAT signaling by ruxolitinib leads to decreases of the U87 cells invasiveness and tumorigenesis. We demonstrate that ruxolitinib may inhibit glioma invasion and tumorigenesis through inhibition of the IFN-induced JAK/STAT signaling pathway.

Conclusion

Collectively, our results revealed that ruxolitinib may have therapeutic potential in glioblastomas, possibly by JAK/STAT signaling triggered by IFN-α and IFN-γ.

Tumor Resection Recruits Effector T Cells and Boosts Therapeutic Efficacy of Encapsulated Stem Cells Expressing IFNβ in Glioblastomas

Purpose: Despite tumor resection being the first-line clinical care for glioblastoma (GBM) patients, nearly all preclinical immune therapy models intend to treat established GBM. Characterizing cytoreductive surgery-induced immune response combined with the administration of immune cytokines has the potential of offering a new treatment paradigm of immune therapy for GBMs.Experimental Design: We developed syngeneic orthotopic mouse GBM models of tumor resection and characterized the immune response of intact and resected tumors. We also created a highly secretable variant of immune cytokine IFNβ to enhance its release from engineered mouse mesenchymal stem cells (MSC-IFNβ) and assessed whether surgical resection of intracranial GBM tumor significantly enhanced the antitumor efficacy of targeted on-site delivery of encapsulated MSC-IFNβ.Results: We show that tumor debulking results in substantial reduction of myeloid-derived suppressor cells (MDSC) and simultaneous recruitment of CD4/CD8 T cells. This immune response significantly enhanced the antitumor efficacy of locally delivered encapsulated MSC-IFNβ via enhanced selective postsurgical infiltration of CD8 T cells and directly induced cell-cycle arrest in tumor cells, resulting in increased survival of mice. Utilizing encapsulated human MSC-IFNβ in resected orthotopic tumor xenografts of patient-derived GBM, we further show that IFNβ induces cell-cycle arrest followed by apoptosis, resulting in increased survival in immunocompromised mice despite their absence of an intact immune system.Conclusions: This study demonstrates the importance of syngeneic tumor resection models in developing cancer immunotherapies and emphasizes the translational potential of local delivery of immunotherapeutic agents in treating cancer. Clin Cancer Res; 23(22); 7047-58. ©2017 AACR.

Immunological Aspects of Malignant Gliomas

Glioblastoma Multiforme (GBM) is the most common malignant primary brain neoplasm having a mean survival time of <24 months. This figure remains constant, despite significant progress in medical research and treatment. The lack of an efficient anti-tumor immune response and the micro-invasive nature of the glioma malignant cells have been explained by a multitude of immune-suppressive mechanisms, proven in different models. These immune-resistant capabilities of the tumor result in a complex interplay this tumor shares with the immune system. We present a short review on the immunology of GBM, discussing the different unique pathological and molecular features of GBM, current treatment modalities, the principles of cancer immunotherapy and the link between GBM and melanoma. Current knowledge on immunological features of GBM, as well as immunotherapy past and current clinical trials, is discussed in an attempt to broadly present the complex and formidable challenges posed by GBM.

Challenges in immunotherapy presented by the glioblastoma multiforme microenvironment

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. Despite intensive treatment, the prognosis for patients with GBM remains grim with a median survival of only 14.6 months. Immunotherapy has emerged as a promising approach for treating many cancers and affords the advantages of cellular-level specificity and the potential to generate durable immune surveillance. The complexity of the tumor microenvironment poses a significant challenge to the development of immunotherapy for GBM, as multiple signaling pathways, cytokines, and cell types are intricately coordinated to generate an immunosuppressive milieu. The development of new immunotherapy approaches frequently uncovers new mechanisms of tumor-mediated immunosuppression. In this review, we discuss many of the current approaches to immunotherapy and focus on the challenges presented by the tumor microenvironment.

Immunostimulants for malignant gliomas

Several immunostimulant approaches have been studied in the treatment of gliomas. The advent of recombinant DNA technology led to a nonspecific immunostimulation via systemic administration of cytokines. Recently, in attempts to more closely mimic their natural activity, cytokines have been delivered by implanting genetically transduced cells or by using in vivo gene transfer techniques. The latest efforts have focused on immunostimulatory agents that act directly on antigen-presenting cells and effector cells of the immune system via pattern recognition receptors. Combining these strategies with more than one mode of immunotherapy may provide better clinical results.

The effect of leukocyte interleukin injection (Multikine) treatment on the peritumoral and intratumoral subpopulation of mononuclear cells and on tumor epithelia: a possible new approach to augmenting sensitivity to radiation therapy and chemotherapy in oral cancer--a multicenter phase I/II clinical Trial

OBJECTIVES/HYPOTHESIS

The main objective of this study was to investigate the effect of the administration of a novel immunoadjuvant, leukocyte interleukin injection, as part of an immuno-augmenting treatment regimen on the peritumoral and intratumoral subpopulations of the tumor infiltrating mononuclear cells and on the epithelial and stromal components, when administered to patients with advanced primary oral squamous cell carcinoma classified as T2-3N0-2M0, as compared with disease-matched control patients (not treated with leukocyte interleukin injection).

STUDY DESIGN

Multicenter Phase I/II clinical trial. Fifty-four patients from four clinical centers were included in the dose-escalating study (27 in each group [leukocyte interleukin injection-treated and control groups]). Cumulative leukocyte inter-leukin injection doses were 2400, 4800, and 8000 IU (as interleukin-2 equivalent).

METHODS

Paraffin-embedded tumor samples obtained at surgical resection of the residual tumor (between days 21 and 28 after treatment initiation) were used. Histological analysis, necrosis evaluation, and American Joint Committee on Cancer grading were performed from H&E-stained sections. Immunohistochemical analysis was performed on three different tumor regions (surface, zone 1; center, zone 2; and tumor-stroma interface, zone 3). Trichrome staining was used to evaluate connective tissue, and morphometric measurements were made using ImagePro analysis software. Cell cycling was determined by the use of Ki-67 marker.

RESULTS

Leukocyte interleukin injection treatment induced a shift from stromal infiltrating T cells toward intraepithelial T cells and posted a significant (P <.05) increase in intraepithelial CD3-positive T cells independent of the leukocyte interleukin injection dose, whereas the increase in CD25 (interleukin-2 receptor alpha [IL-2Ralpha])-positive lymphoid cells was significant only at the lowest leukocyte interleukin injection dose (P <.05). Furthermore, both low- and medium-dose leukocyte interleukin injection treatment induced a significant (P <.05) increase in the number of cycling tumor cells, as compared with control values.

CONCLUSION

The results could be highly beneficial for patients with oral squamous cell carcinoma. First, leukocyte interleukin injection treatment induces T-cell migration into cancer nests and, second, noncycling cancer cells may enter cell cycling on administration of leukocyte interleukin injection. This latter effect may modulate the susceptibility of cancer cells to radiation therapy and chemotherapy. The findings may indicate a need to re-evaluate the way in which follow-up treatment (with radiation therapy and chemotherapy) of patients with head and neck cancer is currently approached.

Locoregional immunotherapy in cancer patients: review of clinical studies

Many patients with invasive cancer have a compromised immune system. This immune dysfunction does appear to start at the site of the tumor. Locoregional immunotherapy is given to stimulate the immune system in order to kill tumor cells either indirectly via a specific or a non-specific way or directly via cell transfer therapy. Advantages to give this immunotherapy locoregionally in stead of systemically are a higher concentration of the immunomodulator at the site of the tumor, to attract or activate effector cells, and diminished toxicity. In this review we have summarised the clinical studies using loco-regional immunotherapy in patients with cancer. Only phase I and II studies were performed. Clinical responses were seen. No single locoregional treatment has become a standard therapy. Relatively few investigations were performed to estimate the influence on the locally effector mechanisms or immune dysfunction. In future clinical trials it is essential to get a better insight in these mechanisms.

Second-generation interferons for cancer: clinical targets

IFNs were the first new therapeutic products resulting from recombinant DNA technology. IFNs were also the first human proteins effective in cancer treatment. There is however much to be discovered which will lead to new clinical applications. Areas which represent major research challenges for full understanding and application of the IFN system are: (i) the diversity of the IFN family; (ii) the role of induction; (iii) molecular mechanism of action; (iv) cellular modulatory effects; (v) advantages of combinations, and (vi) identification of new therapeutic indications. This review will emphasize the diversity of the IFN family and chemical modifications which will result in second-generation IFNs. Pre-clinical and clinical findings form the basis for new therapeutic directions in chronic myelogenous leukemia, lymphomas, myelomas, melanoma, urologic malignancies, primary brain tumors, and ovarian carcinoma.

Intracerebral clysis in a rat glioma model

OBJECTIVE

Intracerebral clysis (ICC) is a new term we use to describe convection-enhanced microinfusion into the brain. This study establishes baseline parameters for preclinical, in vivo, drug investigations using ICC in a rat glioma model.

METHODS

Intracranial pressure was measured, with an intraparenchymal fiber-optic catheter, in male Fischer rats 10, 15, 20, and 25 days after implantation of C6 glioma cells in the right frontal lobe (n = 80) and in control rats without tumor (n = 20), before and during ICC. A 25% albumin solution (100 microl) was infused through an intratumoral catheter at 0.5, 1.0, 2.0, 3.0, and 4.0 microl/min. Infusate distribution was assessed by infusion of fluorescein isothiocyanate-dextran (Mr 20,000), using the aforementioned parameters (n = 36). Brains were sectioned and photographed under ultraviolet light, and distribution was calculated by computer analysis (NIH Image for Macintosh). Safe effective drug distribution was demonstrated by measuring tumor sizes and apoptosis in animals treated with N,N'-bis(2-chloroethyl)-N-nitrosourea via ICC, compared with untreated controls. Magnetic resonance imaging noninvasively confirmed tumor growth before treatment.

RESULTS

Intracranial pressure increased with tumor progression, from 5.5 mm Hg at baseline to 12.95 mm Hg on Day 25 after tumor cell implantation. Intracranial pressure during ICC ranged from 5 to 21 mm Hg and was correlated with increasing infusion volumes and increasing rates of infusion. No toxicity was observed, except at the higher ends of the tumor size and volume ranges. Fluorescein isothiocyanate-dextran distribution was greater with larger infusion volumes (30 microl versus 10 microl, n = 8, P < 0.05). No significant differences in distribution were observed when different infusion rates were compared while the volume was kept constant. At tolerated flow rates, the volumes of distribution were sufficient to promote adequate drug delivery to tumors. N,N'-Bis(2-chloroethyl)-N-nitrosourea treatment resulted in significant decreases in tumor size, compared with untreated controls.

CONCLUSION

The C6 glioma model can be easily modified to study aspects of interstitial delivery via ICC and the application of ICC to the screening of potential antitumor agents for safety and efficacy.

Interferon-alpha enhances CD95L-induced apoptosis of human malignant glioma cells

CD95 ligand (CD95L)-induced apoptosis is a novel immunotherapeutic approach to malignant glioma. Here, we report that interferon-alpha (IFN-alpha) sensitizes LN-229 and T98G human malignant glioma cells to CD95L-induced apoptosis. In contrast to the effects of IFN-gamma and TNF-alpha which sensitize glioma cells to CD95 antibody-induced apoptosis in part by enhancing CD95 expression, IFN-alpha has no effect on CD95 expression at the cell surface of LN-229 and T98G cells. To confirm that changes in CD95 expression are not required for the effects of IFN-alpha, we show that IFN-alpha enhances CD95L-induced apoptosis even in CD95-transfected LN-308 glioma cells. These LN-308 cells have little endogenous CD95 expression but express high levels of CD95 from a stably integrated CD95 expression plasmid. The sensitizing effects of IFN-alpha appear to be independent of cell cycle effects of IFN-alpha and are unaffected by ectopic expression of the bcl-2 proto-oncogene. IFN-alpha enhances CD95L-induced activation of caspase-3, a critical mediator of CD95L-induced cell death. IFN-alpha also increases the cytotoxic effects of BCNU, teniposide and cytarabine in both cell lines, and of vincristine in LN-229 cells. Doxorubicin and 5-fluorouracil toxicity are unaffected by IFN-alpha. IFN-alpha may be a useful adjunct to novel strategies of immunochemotherapy for malignant gliomas that target CD95-mediated apoptosis.

An attempt to generate an antitumor effect in the regional lymph nodes against endometrial cancer cells by inducing antitumor cytokines

Phytohemagglutinin-stimulated regional lymph node cells obtained from gynecological cancer patients exerted a significant antiproliferative activity against an endometrial cancer cell line, RL95-2 on a human tumor clonogenic assay, and released a high amount of tumor necrosis factor alpha (TNF alpha), and interferons. The activity was thought to be partly due to released TNF alpha, because RL95-2 was highly sensitive to recombinant TNF alpha. However, anti-TNF alpha failed to inhibit the activity, which indicated the probability of some as yet unclarified participation of cytokines. Therefore, the regional lymph nodes might be used as sites of endogenous cytokine therapy in endometrial cancer patients.

In vivo inhibition of angiogenesis and growth of the human U-87 malignant glial tumor by treatment with an antibody against basic fibroblast growth factor

The effectiveness of in vivo suppression of neovascularization and growth of malignant glial tumors by in situ administration of an antibody directed against basic fibroblast growth factor (bFGF), a strong mitogen for cells of mesodermal origin, was tested. One hundred fifty congenitally athymic nude rats (han rnu/rnu) were implanted intracerebrally with U-87MG tumor cells, known constitutive producers of bFGF. The animals were randomly assigned to six groups of 25 animals each. Animals were treated by in situ application of saline (Group F), control antibody (Group D), or polyclonal anti-bFGF antibody (Group B). In additional groups a putative effect on tumor growth caused by the treatment application device itself (between growth control Groups A and E), and the effect of heat-inactivated tumor cells (negative control Group C) were tested. After 3 weeks of treatment, tumor progression and degree of neovascularization were morphometrically recorded. In the untreated Groups A and E massive tumor growth was recorded, consisting of 19.9% +/- 0.4% and 27.1% +/- 0.5%, respectively, of the total brain cross-sectional area. In Group C, no tumor growth occurred. In control Groups D and F tumor progression consisted of 18.6% +/- 0.4% and 18.5% +/- 0.4%, respectively, of the total brain cross-sectional area; whereas in the anti-bFGF treated Group B, significantly smaller tumor masses measuring 7.2% +/- 0.1% were recorded. New blood vessels were located both peritumorally and intratumorally and defined as numerical density and area fraction (number/area and area/area). Significantly more new blood vessels were found in Groups A, D, E, and F, ranging from 41,380/mm2 +/- 464/mm2 to 53,442/mm2 +/- 150/mm2 peritumorally and 51,846/mm2 +/- 495/mm2 to 64,660/mm2 +/- 183/mm2 intratumorally than in the anti-bFGF treated Group B, which numbered 8220/mm2 +/- 225/mm2 peritumorally and 16,554/mm2 +/- 236/mm2 intratumorally. The authors conclude that treatment with anti-bFGF antibody is effective in inhibiting tumor-induced angiogenesis and correlated tumor progression. However, owing to the character of the experimental system used, one cannot exclude the possibility that application of the specific anti-bFGF antibody also counteracts device-induced neovascularization. The authors suggest that combined surgical excision and adjuvant immunotherapy of tumors such as glioblastoma and other malignant brain tumors that express bFGF might prevent tumor recurrence.

Transfection-induced tumor necrosis factor-alpha increases the susceptibility of human glioma cells to lysis by lymphokine-activated killer cells: continuous expression of intercellular adhesion molecule-1 on the glioma cells

To develop more effective adoptive immunotherapy, we transfected the human tumor necrosis factor-alpha (TNF-alpha) gene into human glioma cells (U251-SP), which were used as target cells. TNF-alpha is known to increase both the expression of intercellular adhesion molecule-1 (ICAM-1) on the surface of glioma cells and the susceptibility of glioma cells to lymphokine-activated killer (LAK) cell cytolysis. We compared the expression of ICAM-1 induced by TNF-alpha generated by the TNF-alpha gene-transfected cells with that induced by exogenously added TNF-alpha. When the TNF-alpha gene was transfected into U251-SP cells, the expression of ICAM-1 was detected on the cell surface from 3 days after the transfection and continued until at least 9 days. In contrast, it was expressed only transiently in the case of exogenously added TNF-alpha. Also, the cytolytic activity of LAK cells induced by transfection-induced TNF-alpha was significantly stronger than that induced by exogenously added TNF-alpha. The increased susceptibility was quenched by anti-ICAM-1 monoclonal antibody. These data indicated that continuous expression of ICAM-1 induced by TNF-alpha gene transfection of glioma cells resulted in higher cytolytic activity of LAK cells.

Effects of nIFN beta and rIFN gamma on growth and morphology of two human melanoma cell lines: comparison between two- and three-dimensional culture

We compared the anti-proliferative effects of natural interferon beta (nIFN beta) and recombinant interferon gamma (rIFN gamma) on 2 human melanoma cell lines, IGRI and SK-Mel28, grown in 2-dimensional monolayer and in 3-dimensional spheroid culture. In monolayer culture, growth of both lines was inhibited in a dose-dependent manner by 5-day treatments with IFN in concentrations ranging between 1 and 5,000 IU/ml. Incubations with 120 IU/ml nIFN beta or 25 IU/ml rIFN gamma led to a 50% growth inhibition of IGRI cells. A 50% growth inhibition of SK-Me128 cells was obtained with 60 IU/ml nIFN beta, whereas even 5,000 IU/ml rIFN gamma inhibited the growth of this line by only 30%. Growing these melanoma cell lines in 3-dimensional spheroid culture for 5 days reduced their sensitivity to interferon. Growth inhibition values of 50% were achieved with 3,000 IU/ml rIFN gamma or 9,000 IU/ml nIFN beta for IGRI spheroids and 10,000 IU/ml nIFN beta for SK-Me128 spheroids, while 10,000 IU/ml rIFN gamma reduced the growth of SK-Me128 spheroids by only 25%. Outgrowth tests showed that the proliferative capacity after 5-day incubations with IFN was only reduced in IGRI spheroids treated with high doses of nIFN beta. The macroscopically observed increased density of interferon-treated spheroids could be confirmed by light microscopy as corresponding to reduced intercellular space in these spheroids. Scanning electron microscopy furthermore showed variations on the surface of IFN-treated spheroids as well as in cellular organization and structures between cells, hinting at a possible involvement of extracellular matrix substances in the reaction to interferons.(ABSTRACT TRUNCATED AT 250 WORDS)

Addition of IFN-alpha to treatment of malignant brain tumors

Despite many attempts to improve the survival after surgery of patients with malignant astrocytoma the prognosis is poor. We have used natural IFN-alpha in 16 patients with malignant astrocytoma treated between 1987 and 1990; 6 for recurrent tumors. Radiation therapy was given in 2 Gy fractions daily to a total dose of 50 Gy in the tumor area, 5 fractions per week and IFN twice per week, cisplatinum 60 mg/m2 i.v. every second week and vincristine 2 mg every week in 12-h i.v. infusions. Eight patients were reoperated when clinical deterioration suggested recurrent tumor; histological examination showed no residual tumor in 7 of them. Of these 8 patients 3 are alive and well, 2 of them after more than 5 years. The study suggests that malignant astrocytoma can be successfully eradicated with surgery, irradiation, IFN-alpha and chemotherapy. The treatment had, however, unacceptably high neurotoxicity. Earlier removal of the tumor necrosis, before clinical deterioration, could possibly diminish the high complication rate and consequently improve survival.

Induction of growth suppression and modification of gene expression in multi-drug-resistant human glioblastoma multiforme cells by recombinant human fibroblast and immune interferon

The combination of recombinant human fibroblast (IFN-beta) and immune (IFN-gamma) interferon induces enhanced growth suppression and modifies the antigenic phenotype in parental and multi-drug-resistant (MDR) human glioblastoma multiforme (GBM) cells. The present study was conducted to explore the mechanism underlying this cooperative interaction between interferons in inducing growth suppression in MDR-GBM cells. For this analysis we have utilized 2 MDR-GBM cell lines which display a differential sensitivity to growth suppression when exposed to IFN-beta or IFN-gamma. GBM-18-B3 (MDR) cells are more sensitive to growth inhibition by IFN-gamma than by IFN-beta, whereas GBM-18-A3 (MDR) cells are inhibited to a greater degree by IFN-beta than by IFN-gamma. In both cell types, however, growth is suppressed to a greater degree by the combination of interferons than by equivalent concentrations of either type of interferon used alone. Growth suppression induced by the interferons, alone or in combination, was not associated with comparable changes in the steady-state level of MDRI mRNA. In addition, the anti-proliferative effect of interferon was similar in GBM-18 (MDR) cells grown in the presence or absence of colchicine. GBM-18-A3 and GBM-18-B3 cells differed in their de novo and interferon-inducible expression levels of IFN-beta-responsive genes, isg-15 and isg-54. In contrast, both cell types responded in a similar manner with respect to expression of the IFN-gamma-responsive gene, HLA Class II (HLA-DR beta), and HLA Class I, fibronectin and ICAM-I. No further increase in expression of any of the genes was observed which was unique to the combination of interferons.

Potentiation of growth suppression and modulation of the antigenic phenotype in human melanoma cells by the combination of recombinant human fibroblast and immune interferons

Administration of interferon as a single therapeutic regimen in cancer patients with various neoplasias has had only limited efficacy in ameliorating the negative clinical course of their disease. In the present study, we have evaluated the effect of recombinant human fibroblast (IFN beta) and immune (IFN gamma) interferon, alone and in combination, on growth, differentiation and the expression of class I and II histocompatibility locus antigens (HLA) and melanoma-associated antigens on the human melanoma cell line H0-1. The effect of combinations of interferons on the antigenic profile of human melanoma cells displaying different organ colonization and spontaneous metastatic potential in athymic nude mice was also determined. H0-1 cells were more sensitive to the antiproliferative activity of IFN beta than to IFN gamma and the combination of interferons resulted in a potentiation of growth suppression. The antiproliferative effect of both interferons was greater in later-passage than in earlier-passage H0-1 cells, possibly reflecting alterations in the evolving tumor cell population as a result of long-term in vitro propagation and/or the selective outgrowth of cells with an increased growth rate. The enhanced growth suppression observed in H0-1 cells treated with the combination of IFN beta plus IFN gamma was not associated with a significant increase in the level of melanin, a marker of melanoma differentiation, above that observed with either interferon used alone. IFN beta and IFN gamma differentially modulated the expression of class I and II HLA and melanoma-associated antigens in H0-1 cells and a series of melanoma cells with different organ colonization and metastatic potential, including MeWo, MeM 50-10, MeM 50-17, 3S5 and 70W. No consistent potentiation or antagonism in the expression of any specific antigen was observed in any of the melanoma cell lines exposed to the combination of interferons. The present study demonstrates that the combination of IFN beta plus IFN gamma can potentiate growth suppression in H0-1 human melanoma cells and that this effect is not associated with an increase in differentiation or a potentiation in antigenic modulation. In addition, no direct correlation between the expression of any specific antigen or its modulation by IFN beta or IFN gamma, alone or in combination, and organ colonization and metastatic potential in nude mice was observed in the different melanoma cell lines.

Expression and modulation by cytokines of the intercellular adhesion molecule-1 (ICAM-1) in human central nervous system tumor cell cultures

The intercellular adhesion molecule (ICAM-1) has been shown to be important in interactions involving cells of the immune system and to be upregulated in a number of cell culture systems by cytokines, including immune interferon (IFN-gamma) and tumor necrosis factor-alpha (TNF-alpha). In the present study, we have determined by fluorescence-activated cell sorter (FACS) analysis and the anti-ICAM-1 monoclonal antibody (MAb) CL203.4 the base-line expression of ICAM-1 and its modulation by recombinant IFN-beta, IFN-gamma and TNF-alpha in early passage (less than 15) human central nervous system (CNS) tumor-derived cell cultures. These cultures were established from various malignancies, including glioblastoma multiforme (GBM), astrocytoma (AST), ganglioglioma, medulloblastoma, meningioma and a pineal tumor. ICAM-1 expression was highest in the GBM- and AST-derived cell cultures and was lowest in the ganglioglioma and normal pineal cell cultures. Variable ICAM-1 expression was found, however, in tumors of the same histological group. In several cell cultures the variable expression observed by FACS was substantiated by the intensity of the molecular species immunoprecipitated by the anti-ICAM-1 MAb CL203.4 from these cells. All the cell cultures displayed variable but consistent increases in ICAM-1 expression following treatment with IFN-gamma or TNF-alpha. In general, the degree of increase in ICAM-1 expression was greatest in cultures exposed to TNF-alpha. Upregulation of ICAM-1 expression in an established glioblastoma multiforme cell line was of greater magnitude and more rapid following TNF-alpha treatment (within 2 to 3 hr) than exposure to IFN-gamma (by 24 hr). In several cultures, IFN-beta also increased ICAM-1 expression and enhanced the increase induced by TNF-alpha. The results of the present study indicate that variable expression of ICAM-1 is a common property of early passage cultures of CNS tumors and recombinant interferons and TNF-alpha can differentially upregulate ICAM-1 expression in these CNS tumor cell cultures.