CD40 is functionally expressed on human breast carcinomas: variable inducibility by cytokines and enhancement of Fas-mediated apoptosis

Approaches for refining and furthering the development of CAR-based T cell therapies for solid malignancies

Introduction: Chimeric antigen receptor-engineered T-cells typically use the binding domains of antibodies to target cytotoxicity toward tumors. This approach has produced great efficacy against selected hematological cancers, but benefit in solid tumors has been limited. Characteristically, the microenvironment in solid tumors restricts CAR T cell function, thereby limiting success. Enhancing efficacy will depend on novel target discovery to refine specificity and reduce toxicity. Additionally, overcoming immunosuppressive mechanisms may be achieved by altering the structure of the CAR itself, together with ancillary gene expression or additional therapeutic interventions.Areas covered: Herein, the authors discuss approaches for refining and further developing CAR T cell therapies specifically for use with solid malignancies. The authors survey the existing literature and provide perspectives for the future.Expert opinion: Pronounced efficacy in solid tumors will likely require combination therapies, targeting both the tumor itself and associated immunosuppressive mechanisms. Future exploration of CAR T cell therapies for solid tumors is likely to incorporate next-generation designs that couple more precise targeting of cancer-associated targets with enhanced potency and resistance to exhaustion.

Tackling Immune Targets for Breast Cancer: Beyond PD-1/PD-L1 Axis

The burden of breast cancer is imposing a huge global problem. Drug discovery research and novel approaches to treat breast cancer have been carried out extensively over the last decades. Although immune checkpoint inhibitors are showing promising preclinical and clinical results in treating breast cancer, they are facing multiple limitations. From an immunological perspective, a recent report highlighted breast cancer as an "inflamed tumor" with an immunosuppressive microenvironment. Consequently, researchers have been focusing on identifying novel immunological targets that can tune up the tumor immune microenvironment. In this context, several novel non-classical immune targets have been targeted to determine their ability to uncouple immunoregulatory pathways at play in the tumor microenvironment. This article will highlight strategies designed to increase the immunogenicity of the breast tumor microenvironment. It also addresses the latest studies on targets which can enhance immune responses to breast cancer and discusses examples of preclinical and clinical trial landscapes that utilize these targets.

Future of immunotherapy in pancreas cancer and the trials, tribulations and successes thus far

Pancreas ductal adenocarcinoma (PDAC) has a dismal prognosis with a 5-year survival rate of 10%. Currently, chemotherapy remains the standard of care for systemic treatment. Immunotherapy with checkpoint inhibitors unfortunately has not been found to be effective in the treatment of PDAC to date, likely due to the highly desmoplastic and immunosuppressive tumor microenvironment (TME). Treatment targeting pathways against the immunosuppressive mechanisms of PDAC are of mounting interest to improve outcomes in PDAC. In this review, we discuss prior efforts and the current state of immunotherapy in PDAC. We will also review the emerging targets and treatments with significant clinical potential for the treatment of PDAC such as: CD40 pathway, the adenosine pathway, the CXCR4/CXCL12 axis, the CCR2/CCL2 axis, IDO pathway, and others.

Targeting eukaryotic proteases for natural products-based drug development

Covering: up to April 2020 Proteases are involved in the regulation of many physiological processes. Their overexpression and dysregulated activity are linked to diseases such as hypertension, diabetes, viral infections, blood clotting disorders, respiratory diseases, and cancer. Therefore, they represent an important class of therapeutic targets. Several protease inhibitors have reached the market and >60% of them are directly related to natural products, even when excluding synthetic natural product mimics. Historically, natural products have been a valuable and validated source of therapeutic agents, as over half of the marketed drugs across targets and diseases are inspired by natural product structures. In the past two decades the number of new protease inhibitors discovered from nature has sharply increased. Additionally, the availability of 3D structural information for proteases has permitted structure-based design and accelerated the synthesis of optimized lead structures with improved potency and selectivity profiles, resulting in some of the most-potent-in-class inhibitors. These discoveries were oftentimes maximized by in-depth biological assessments of lead inhibitors, linking them to a relevant disease state. This review will discuss some of the current and emerging drug targets and their involvement in various disease processes, highlighting selected success stories behind several FDA-approved protease inhibitors that have natural products scaffolds as well as recent selected pharmacologically well-characterized inhibitors derived from marine or terrestrial sources.

The Use of Anti-CD40 mAb in Cancer

Immunomodulatory monoclonal antibody (mAb) therapy is at the forefront of developing cancer therapeutics with numerous targeted agents proving highly effective in selective patients at stimulating protective host immunity, capable of eradicating established tumours and leading to long-term disease-free states. The cell surface marker CD40 is expressed on a range of immune cells and transformed cells in malignant states whose signalling plays a critical role in modulating adaptive immune responses. Anti-CD40 mAb therapy acts via multiple mechanisms to stimulate anti-tumour immunity across a broad range of lymphoid and solid malignancies. A wealth of preclinical research in this field has led to the successful development of multiple anti-CD40 mAb agents that have shown promise in early-phase clinical trials. Significant progress has been made to enhance the engagement of antibodies with immune effectors through their interactions with Fcγ receptors (FcγRs) by the process of Fc engineering. As more is understood about how to best optimise these agents, principally through the fine-tuning of mAb structure and choice of synergistic partnerships, our ability to generate robust, clinically beneficial anti-tumour activity will form the foundation for the next generation of cancer therapeutics.

On the Other Side: Manipulating the Immune Checkpoint Landscape of Dendritic Cells to Enhance Cancer Immunotherapy

Monoclonal antibodies targeting co-inhibitory immune checkpoint molecules have been successful in clinical trials of both solid and hematological malignancies as acknowledged by the 2018 Nobel Prize in Medicine, however improving clinical response rates is now key to expanding their efficacy in areas of unmet medical need. Antibodies to checkpoint inhibitors target molecules on either T cells or tumor cells to stimulate T cells or remove tumor mediated immunosuppression, respectively. However, many of the well-characterized T cell immune checkpoint receptors have their ligands on antigen presenting cells or exert direct effects on those cells. Dendritic cells are the most powerful antigen presenting cells; they possess the ability to elicit antigen-specific responses and have important roles in regulation of immune tolerance. Despite their theoretical benefits in cancer immunotherapy, the translation of DC therapies into the clinic is yet to be fully realized and combining DC-based immunotherapy with immune checkpoint inhibitors is an attractive strategy. This combination takes advantage of the antigen presenting capability of DC to maximize specific immune responses to tumor antigens whilst removing tumor-associated immune inhibitory mechanisms with immune checkpoint inhibition. Here we review the expression and functional effects of immune checkpoint molecules on DC and identify rational combinations for DC vaccination to enhance antigen-specific T cell responses, cytokine production, and promotion of long-lasting immunological memory.

Atrial Fibrillation during Adjuvant Chemotherapy with Docetaxel: A Case Report

A 46-year-old woman had an episode of atrial fibrillation during infusion of docetaxel as adjuvant chemotherapy for an infiltrating ductal carcinoma of the breast. All cardiological tests performed before treatment were normal and there was no evidence of thyroid dysfunction nor any objective or anamnestic data indicating acute or chronic cardiovascular disease. None of the drugs administered has ever shown any proarrhythmic activity. In controlled clinical trials docetaxel was found to have a very low cardiotoxicity.

Structural Diversity and Anticancer Activity of Marine-Derived Elastase Inhibitors: Key Features and Mechanisms Mediating the Antimetastatic Effects in Invasive Breast Cancer

Three new 3-amino-6-hydroxy-2-piperidone (Ahp)-containing cyclic depsipeptides, named loggerpeptins A-C (1-3), along with molassamide (4), were discovered from a marine cyanobacterium, extending the structural diversity of this prevalent scaffold of cyanobacterial serine protease inhibitors. Molassamide, which contains a 2-amino-butenoic (Abu) unit in the cyclic core, was the most potent and selective analogue against human neutrophil elastase (HNE). Given the growing evidence supporting the role of HNE in breast cancer progression and metastasis, we assessed the cellular effects of compounds 3 and 4 in the context of targeting invasive breast cancer. Both compounds inhibited cleavage of the elastase substrate CD40 in biochemical assays; however, only 4 exhibited significant cellular activity. As CD40 and other receptor proteolytic processing culminates in NFκB activation, we assessed the effects of 4 on the expression of target genes, including ICAM-1. ICAM-1 is also a direct target of elastase and, in our studies, compound 4 attenuated both elastase-induced ICAM-1 gene expression and ICAM-1 proteolytic processing by elastase, revealing a potential dual effect on migration through modulation of gene expression and proteolytic processing. Molassamide also specifically inhibited the elastase-mediated migration of highly invasive triple-negative breast cancer cells.

Cd40 Activation as Potential Tool in Malignant Neoplasms

Background

CD40, a cell surface molecule, is expressed on B-cell malignancies and many different solid tumors. It is capable of mediating diverse biological phenomena such as the induction of apoptosis in tumors and stimulation of the immune response. It has thus been studied as a possible target for antitumor therapy. The general aim of this review is to focus the attention of clinical oncologists on the involvement of CD40 in tumors and the rationale of CD40-activation-based therapies in new, biologically oriented antitumor protocols.

Methods

A Medline review of published papers about the role of CD40 activation in cancer therapy.

Results

Many authors have shown that CD40 activation promotes apoptotic death of tumor cells and that the presence of the molecule on the surface of carcinoma lines is an important factor in the generation of tumor-specific T-cell responses that contribute to tumor cell elimination. The CD40 ligand (CD40L) is the natural ligand for CD40; it is expressed primarily on the surface of activated T lymphocytes. Preclinical studies suggest that CD40-CD40L interaction could be useful for cytotoxicity against CD40-expressing tumors and for immune stimulation. Tumor inhibition was observed when tumor cells were treated with agonistic anti-CD40 monoclonal antibodies or with the soluble form of CD40L. The results of the first phase I clinical trial to treat cancer patients with subcutaneous injection of recombinant human CD40L have been recently reported. Immunohistochemical studies have revealed that detection of CD40 in primary cutaneous malignant melanoma and lung cancer may have a negative prognostic value. Interestingly, up-regulation of CD40 was observed in the tumor vessels of renal carcinomas and Kaposi's sarcoma, suggesting possible involvement of CD40 in tumor angiogenesis. Recently, it has also been shown that CD40 engagement on endothelial cells induces in vitro tubule formation and expression of matrix metalloproteinases, two processes involved in the neovascularization and progression of tumors.

Conclusions

CD40 activation represents an exciting target for hematological malignancies and solid tumors expressing the molecule, but its functional role in cancer development still remains unclear and controversial.

CD30/CD30 Ligand and CD40/CD40 Ligand in Malignant Lymphoid Disorders

CD30 and CD40 are members of the tumor necrosis factor (TNF) receptor family. These two receptors have pleiotropic biologic functions including induction of apoptosis and enhancing cell survival. This review will discuss the pattern of expression of these receptors in malignant lymphoid disorders and their prospective ligands. Understanding issues related to these two ligands and their receptors in lymphoid malignancies may help to improve the classification of these diseases and could open the doors for new treatment strategies.

Direct Interaction of CD40 on Tumor Cells with CD40L on T Cells Increases the Proliferation of Tumor Cells by Enhancing TGF-β Production and Th17 Differentiation

It has recently been reported that the CD40-CD40 ligand (CD40L) interaction is important in Th17 development. In addition, transforming growth factor-beta (TGF-β) promotes tumorigenesis as an immunosuppressive cytokine and is crucial in the development of Th17 cells. This study investigated the role of CD40 in breast cancer cells and its role in immunosuppressive function and tumor progression. CD40 was highly expressed in the breast cancer cell line MDA-MB231, and its stimulation with CD40 antibodies caused the up-regulation of TGF-β. Direct CD40-CD40L interaction between MDA-MB231 cells and activated T cells also increased TGF-β production and induced the production of IL-17, which accelerated the proliferation of MDA-MB231 cells through the activation of STAT3. Taken together, the direct CD40-CD40L interaction of breast tumor cells and activated T cells increases TGF-β production and the differentiation of Th17 cells, which promotes the proliferation of breast cancer cells.

Enhancing antitumor efficacy of chimeric antigen receptor T cells through constitutive CD40L expression

Adoptive cell therapy with genetically modified T cells expressing a chimeric antigen receptor (CAR) is a promising therapy for patients with B-cell acute lymphoblastic leukemia. However, CAR-modified T cells (CAR T cells) have mostly failed in patients with solid tumors or low-grade B-cell malignancies including chronic lymphocytic leukemia with bulky lymph node involvement. Herein, we enhance the antitumor efficacy of CAR T cells through the constitutive expression of CD40 ligand (CD40L, CD154). T cells genetically modified to constitutively express CD40L (CD40L-modified T cells) demonstrated increased proliferation and secretion of proinflammatory TH1 cytokines. Further, CD40L-modified T cells augmented the immunogenicity of CD40(+) tumor cells by the upregulated surface expression of costimulatory molecules (CD80 and CD86), adhesion molecules (CD54, CD58, and CD70), human leukocyte antigen (HLA) molecules (Class I and HLA-DR), and the Fas-death receptor (CD95). Additionally, CD40L-modified T cells induced maturation and secretion of the proinflammatory cytokine interleukin-12 by monocyte-derived dendritic cells. Finally, tumor-targeted CD19-specific CAR/CD40L T cells exhibited increased cytotoxicity against CD40(+) tumors and extended the survival of tumor-bearing mice in a xenotransplant model of CD19(+) systemic lymphoma. This preclinical data supports the clinical application of CAR T cells additionally modified to constitutively express CD40L with anticipated enhanced antitumor efficacy.

Multifunctional CD40L: pro- and anti-neoplastic activity

The CD40 ligand is a type I transmembrane protein that belongs to a tumor necrosis factor (TNF) superfamily. It is present not only on the surface of activated CD4+ T cells, B cells, blood platelets, monocytes, and natural killer (NK) cells but also on cancer cells. The receptor for ligand is constitutively expressed on cells, TNF family protein: CD40. The role of the CD40/CD40L pathway in the induction of body immunity, in inflammation, or in hemostasis has been well documented, whereas its involvement in neoplastic disease is still under investigation. CD40L ligand may potentiate apoptosis of tumor cells by activation of nuclear factor-κB (NF-κB), AP-1, CD95, or caspase-depended pathways and stimulate host immunity to defend against cancer. Although CD40L has a major contribution to anti-cancer activity, many reports point at its ambivalent nature. CD40L enhance release of strongly pro-angiogenic factor, vascular endothelial growth factor (VEGF), and activator of coagulation, TF, the level of which is correlated with tumor metastasis. CD40L involvement in the inhibition of tumor progression has led to the emergence of not only therapy using recombinant forms of the ligand and vaccines in the treatment of cancer but also therapy consisting of inhibiting platelets-main source of CD40L. This article is a review of studies on the ambivalent role of CD40L in neoplastic diseases.

CD40 expression in renal cell carcinoma is associated with tumor apoptosis, CD8(+) T cell frequency and patient survival

The co-stimulatory molecule, CD40, is expressed in renal cell carcinoma (RCC) and a variety of inflammatory diseases in the kidney. We investigated the relationship between tumor-associated CD40 expression, immune milieu of the tumor microenvironment, tumor stage and survival of patients with RCC. The expression of CD40, TUNEL and CD8 in human renal cell carcinomas was analyzed by immunohistochemistry performed on tissue samples obtained at the time of surgery. Computer-assisted quantitation of protein expression was used to analyze results in connection with patient survival and tumor stage. We show for the first time that tumor-associated CD40 expression is associated with prolonged survival in RCC patients. Tumor apoptosis (TUNEL) and CD8 immunostaining were also associated with patient survival. No relation was observed between CD40 expression and tumor stage. Our results suggest CD40 may be a prognostic biomarker indicative of prolonged RCC patient survival. Strategies that up-regulate CD40 expression in some RCC patients may thus improve survival, supporting further studies of agonistic CD40 antibodies in RCC.

Breast cancer immunobiology driving immunotherapy: vaccines and immune checkpoint blockade

Breast cancer is immunogenic, and infiltrating immune cells in primary breast tumors convey important clinical prognostic and predictive information. Furthermore, the immune system is critically involved in clinical responses to some standard cancer therapies. Early breast cancer vaccine trials have established the safety and bioactivity of breast cancer immunotherapy, with hints of clinical activity. Novel strategies for modulating regulators of immunity, including regulatory T cells, myeloid-derived suppressor cells and immune checkpoint pathways (monoclonal antibodies specific for the cytotoxic T-lymphocyte antigen-4 or programmed death), are now available. In particular, immune checkpoint blockade has enormous therapeutic potential. Integrative breast cancer immunotherapies that strategically combine established breast cancer therapies with breast cancer vaccines, immune checkpoint blockade or both should result in durable clinical responses and increased cures.

TWEAK signals through JAK-STAT to induce tumor cell apoptosis

The TWEAK receptor Fn14 (TNFRSF12), a member of the TNF Receptor superfamily, can mediate many processes, including apoptosis. Fn14 agonists have therefore been the subject of interest as potential cancer therapeutics. In cell culture experiments, interferon gamma (IFNγ) is typically required for induction of apoptotic activity by either TWEAK or Fn14 agonistic antibodies in most cell lines. We have investigated the mechanism of IFNγ signaling and the role of JAK-STAT signaling in TWEAK/Fn14-mediated tumor cell killing. We found that IFNγ-mediated enhancement of tumor cell killing is JAK-STAT dependent, as JAK inhibitors block IFNγ-dependent TWEAK induced apoptosis. Exposure of tumor cells to IFNγ results in an increase in Fn14 expression on the cell surface, which may be a mechanism by which IFNγ induces sensitivity to TWEAK. In a reciprocal fashion, we observed that IFNγ receptor levels increase in response to TWEAK treatment in WiDr cells. Significantly, we found that TWEAK alone can induce STAT1 phosphorylation in WiDr tumor cells. Moreover, TWEAK induction of tumor cell apoptosis in WiDr cells in the absence of IFNγ is mediated by the JAK-STAT pathway. Correspondingly, we show that treatment of tumor bearing mice with mBIIB036, an Fn14 agonistic antibody, results in STAT1 phosphorylation in the tumors. Notably, the level of STAT1 phosphorylation appears to correlate with the degree of tumor growth inhibition by BIIB036 in vivo. Additionally, in WiDr cells, TWEAK induces a soluble factor, which we have identified as IFNβ, capable of independently inducing STAT1 phosphorylation when transferred to naïve cells. Finally, either IFNα or IFNβ can partially substitute for IFNγ in sensitizing tumor cells to Fn14 agonists. In summary, we show that TWEAK/Fn14 can signal through the JAK-STAT pathway to induce IFNβ, and that the ability of TWEAK to induce tumor cell apoptosis is mediated by JAK-STAT signaling. We also demonstrate that IFNγ enhancement of TWEAK/FN14-mediated tumor cell death is JAK-dependent and may occur by IFNγ-dependent upregulation of Fn14 on tumor cells. These findings may have implications for the appropriately targeted clinical development of Fn14 agonists as anti-cancer therapy.

Glyceollins as novel targeted therapeutic for the treatment of triple-negative breast cancer

The purpose of this study was to investigate the effects of glyceollins on the suppression of tumorigenesis in triple-negative breast carcinoma cell lines. We further explored the effects of glyceollins on microRNA and protein expression in MDA-MB-231 cells. Triple-negative (ER-, PgR- and Her2/neu-) breast carcinoma cells were used to test the effects of glyceollins on tumorigenesis in vivo. Following this procedure, unbiased microarray analysis of microRNA expression was performed. Additionally, we examined the changes in the proteome induced by glyceollins in the MDA-MB-231 cells. Tumorigenesis studies revealed a modest suppression of MDA-MB-231 and MDA-MB-468 cell tumor growth in vivo. In response to glyceollins we observed a distinct change in microRNA expression profiles and proteomes of the triple-negative breast carcinoma cell line, MDA-MB-231. Our results demonstrated that the glyceollins, previously described as anti-estrogenic agents, also exert antitumor activity in triple-negative breast carcinoma cell systems. This activity correlates with the glyceollin alteration of microRNA and proteomic expression profiles.

Primary and malignant cholangiocytes undergo CD40 mediated Fas dependent apoptosis, but are insensitive to direct activation with exogenous Fas ligand

INTRODUCTION

Cholangiocarcinoma is a rare malignancy of the biliary tract, the incidence of which is rising, but the pathogenesis of which remains uncertain. No common genetic defects have been described but it is accepted that chronic inflammation is an important contributing factor. We have shown that primary human cholangiocyte and hepatocyte survival is tightly regulated via co-operative interactions between two tumour necrosis family (TNF) receptor family members; CD40 and Fas (CD95). Functional deficiency of CD154, the ligand for CD40, leads to a failure of clearance of biliary tract infections and a predisposition to cholangiocarcinoma implying a direct link between TNF receptor-mediated apoptosis and the development of cholangiocarcinoma.

AIMS

To determine whether malignant cholangiocytes display defects in CD40 mediated apoptosis. By comparing CD40 and Fas-mediated apoptosis and intracellular signalling in primary human cholangiocytes and three cholangiocyte cell lines.

RESULTS

Primary cholangiocytes and cholangiocyte cell lines were relatively insensitive to direct Fas-mediated killing with exogenous FasL when compared with Jurkat cells, which readily underwent Fas-mediated apoptosis, but were extremely sensitive to CD154 stimulation. The sensitivity of cells to CD40 activation was similar in magnitude in both primary and malignant cells and was STAT-3 and AP-1 dependent in both.

CONCLUSIONS

1) Both primary and malignant cholangiocytes are relatively resistant to Fas-mediated killing but show exquisite sensitivity to CD154, suggesting that the CD40 pathway is intact and fully functional in both primary and malignant cholangiocytes 2) The relative insensitivity of cholangiocytes to Fas activation demonstrates the importance of CD40 augmentation of Fas dependent death in these cells. Agonistic therapies which target CD40 and associated intracellular signalling pathways may be effective in promoting apoptosis of malignant cholangiocytes.

Direct inhibition of elastase activity by indole-3-carbinol triggers a CD40-TRAF regulatory cascade that disrupts NF-kappaB transcriptional activity in human breast cancer cells

Treatment of highly tumorigenic MDA-MB-231 human breast cancer cells with indole-3-carbinol (I3C) directly inhibited the extracellular elastase-dependent cleavage of membrane-associated CD40, a member of the tumor necrosis factor (TNF) receptor superfamily. CD40 signaling has been implicated in regulating cell survival, apoptosis, and proliferation, as well as in sensitizing breast cancer cells to chemotherapy, and is therefore an important potential target of novel breast cancer treatments. The I3C-dependent accumulation of full-length unprocessed CD40 protein caused a shift in CD40 signaling through TNF receptor-associated factors (TRAF), including the TRAF1/TRAF2 positive regulators and TRAF3 negative regulator of NF-kappaB transcription factor activity. Because TRAF1 is a transcriptional target gene of NF-kappaB, I3C disrupted a positive feedback loop involving these critical cell survival components. siRNA ablation of elastase expression mimicked the I3C inhibition of CD40 protein processing and G(1) cell cycle arrest, whereas siRNA knockdown of TRAF3 and the NF-kappaB inhibitor IkappaB prevented the I3C-induced cell cycle arrest. In contrast, siRNA knockdown of PTEN had no effect on the I3C control of NF-kappaB activity, showing the importance of CD40 signaling in regulating this transcription factor. Our study provides the first direct in vitro evidence that I3C directly inhibits the elastase-mediated proteolytic processing of CD40, which alters downstream signaling to disrupt NF-kappaB-induced cell survival and proliferative responses. Furthermore, we have established a new I3C-mediated antiproliferative cascade that has significant therapeutic potential for treatment of human cancers associated with high levels of elastase and its CD40 membrane substrate.

Molecular mechanism and function of CD40/CD40L engagement in the immune system

SUMMARY

During the generation of a successful adaptive immune response, multiple molecular signals are required. A primary signal is the binding of cognate antigen to an antigen receptor expressed by T and B lymphocytes. Multiple secondary signals involve the engagement of costimulatory molecules expressed by T and B lymphocytes with their respective ligands. Because of its essential role in immunity, one of the best characterized of the costimulatory molecules is the receptor CD40. This receptor, a member of the tumor necrosis factor receptor family, is expressed by B cells, professional antigen-presenting cells, as well as non-immune cells and tumors. CD40 binds its ligand CD40L, which is transiently expressed on T cells and other non-immune cells under inflammatory conditions. A wide spectrum of molecular and cellular processes is regulated by CD40 engagement including the initiation and progression of cellular and humoral adaptive immunity. In this review, we describe the downstream signaling pathways initiated by CD40 and overview how CD40 engagement or antagonism modulates humoral and cellular immunity. Lastly, we discuss the role of CD40 as a target in harnessing anti-tumor immunity. This review underscores the essential role CD40 plays in adaptive immunity.

Preferential killing of cancer cells and activated human T cells using ZnO nanoparticles

Nanoparticles are increasingly being recognized for their potential utility in biological applications including nanomedicine. Here we examine the response of normal human cells to ZnO nanoparticles under different signaling environments and compare it to the response of cancerous cells. ZnO nanoparticles exhibit a strong preferential ability to kill cancerous T cells ( approximately 28-35x) compared to normal cells. Interestingly, the activation state of the cell contributes toward nanoparticle toxicity, as resting T cells display a relative resistance while cells stimulated through the T cell receptor and CD28 costimulatory pathway show greater toxicity in direct relation to the level of activation. Mechanisms of toxicity appear to involve the generation of reactive oxygen species, with cancerous T cells producing higher inducible levels than normal T cells. In addition, nanoparticles were found to induce apoptosis and the inhibition of reactive oxygen species was found to be protective against nanoparticle induced cell death. The novel findings of cell selective toxicity, towards potential disease causing cells, indicate a potential utility of ZnO nanoparticles in the treatment of cancer and/or autoimmunity.

CD40-mediated death and cytokine secretion in colorectal cancer: a potential target for inflammatory tumour cell killing

CD40, a member of the tumour necrosis factor family, is expressed in a variety of epithelial cells. Although soluble CD40 agonists are growth-inhibitory, membrane-presented CD40 ligand (CD40L) induces extensive apoptosis in carcinoma cells. This study investigated whether CD40 is expressed in human colorectal carcinoma (CRC) cells and explored the functional consequences of CD40 ligation. CD40 expression in a panel of CRC lines was assessed by flow cytometry and in resected human CRCs by immunohistochemistry. CRC cells were treated in vitro with soluble CD40 agonists or cocultured with fibroblasts expressing membrane-bound CD40 ligand. Apoptosis was determined by flow cytometry using Annexin V/propidium iodide labelling and by a DNA fragmentation assay. Cytokine secretion induced by CD40 ligation was quantified by a multiplex-bead array approach. We show that CD40 is expressed in a proportion of established CRC lines in culture and that receptor expression is functional. Activation of CD40 by membrane-presented CD40L, but not soluble agonists, causes high levels of death in CD40-positive CRC cells and induces secretion of proinflammatory cytokines. In agreement with our in vitro observations, immunohistochemical studies demonstrated that CD40 is highly expressed in a proportion of colorectal cancer specimens. The high level of susceptibility of CRC cells to CD40-killing combined with the ability of CD40 to induce concomitant secretion of proinflammatory cytokines suggest that CD40 ligation may represent a novel mechanism for elimination of CRC cells and render CD40 a promising therapeutic target for the eradication of colorectal tumours.

Towards a therapeutic breast cancer vaccine: the next steps

The genomic revolution has advanced our understanding of breast cancer biology and the molecular basis of antitumor immunity. Trastuzumab, the first monoclonal antibody for breast cancer, is now a routine part of clinical care. Breast cancer vaccines may be more effective by actively recruiting both humoral and cellular immunity to the therapeutic effort. However, immunization alone is unlikely to have significant activity against established breast cancers, where it is limited by potent mechanisms of immune tolerance and the immunobiology of breast cancer itself. The next generation of clinical studies should integrate breast cancer vaccines with standard breast cancer drugs or novel immunotherapeutics in strategic doses and schedules that abrogate immune tolerance and groom the tumor microenvironment for a productive immune response.

Prospect of targeting the CD40 pathway for cancer therapy

The cell surface molecule CD40 is a member of the tumor necrosis factor receptor superfamily and is broadly expressed by immune, hematopoietic, vascular, epithelial, and other cells, including a wide range of tumor cells. CD40 itself lacks intrinsic kinase or other signal transduction activity but rather mediates its diverse effects via an intricate series of downstream adapter molecules that differentially alter gene expression depending on cell type and microenvironment. As a potential target for novel cancer therapy, CD40 may mediate tumor regression through both an indirect effect of immune activation and a direct cytotoxic effect on the tumor, resulting in a "two-for-one" mechanism of action of CD40 agonists. Several drug formulations that target the CD40 pathway have undergone phase 1 clinical evaluation in advanced-stage cancer patients, and initial findings show objective clinical responses and immune modulation in the absence of major toxicity.

Anti-CD40 agonist antibodies: preclinical and clinical experience

The cell-surface molecule CD40, a member of the tumor necrosis factor receptor superfamily, broadly regulates immune activation and mediates tumor apoptosis. CD40 is expressed by antigen-presenting cells (APC) and engagement of its natural ligand on T cells activates APC including dendritic cells and B cells. Agonistic CD40 antibodies have been shown to substitute for T cell help provided by CD4+ lymphocytes in murine models of T cell-mediated immunity. In tumor-bearing hosts, CD40 agonists trigger effective immune responses against tumor-associated antigens. In contrast, CD40 is also expressed on many tumor cells and its ligation in this setting mediates a direct cytotoxic effect. Engagement of CD40 on tumor cells results in apoptosis in vitro and impaired tumor growth in vivo. These observations have prompted efforts to use agonistic CD40 antibodies for the treatment of cancer patients and initial clinical results have been promising.

Clinical activity and immune modulation in cancer patients treated with CP-870,893, a novel CD40 agonist monoclonal antibody

PURPOSE

The cell-surface molecule CD40 activates antigen-presenting cells and enhances immune responses. CD40 is also expressed by solid tumors, but its engagement results in apoptosis. CP-870,893, a fully human and selective CD40 agonist monoclonal antibody (mAb), was tested for safety in a phase I dose-escalation study.

PATIENTS AND METHODS

Patients with advanced solid tumors received single doses of CP-870,893 intravenously. The primary objective was to determine safety and the maximum-tolerated dose (MTD). Secondary objectives included assessment of immune modulation and tumor response.

RESULTS

Twenty-nine patients received CP-870,893 in doses from 0.01 to 0.3 mg/kg. Dose-limiting toxicity was observed in two of seven patients at the 0.3 mg/kg dose level (venous thromboembolism and grade 3 headache). MTD was estimated as 0.2 mg/kg. The most common adverse event was cytokine release syndrome (grade 1 to 2) which included chills, rigors, and fever. Transient laboratory abnormalities affecting lymphocytes, monocytes, platelets, D-dimer and liver function tests were observed 24 to 48 hours after infusion. Four patients with melanoma (14% of all patients and 27% of melanoma patients) had objective partial responses at restaging (day 43). CP-870,893 infusion resulted in transient depletion of CD19+ B cells in blood (93% depletion at the MTD for < 1 week). Among B cells remaining in blood, we found a dose-related upregulation of costimulatory molecules after treatment.

CONCLUSION

The CD40 agonist mAb CP-870,893 was well tolerated and biologically active, and was associated with antitumor activity. Further studies of repeated doses of CP-870,893 alone and in combination with other antineoplastic agents are warranted.

CD40 signaling predicts response to preoperative trastuzumab and concomitant paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide in HER-2-overexpressing breast cancer

INTRODUCTION

We performed gene expression analysis to identify molecular predictors of resistance to preoperative concomitant trastuzumab and paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide (T/FEC).

METHODS

Pretreatment fine-needle aspiration specimens from 45 patients with HER-2-overexpressing stage II to IIIA breast cancer were subjected to transcriptional profiling and examined for differential expression of various genes and gene sets. The primary endpoint for tumor response was pathologic complete response (pCR). Correlations between pCR and gene expression were sought.

RESULTS

The overall pCR rate was 64%. Age, nuclear grade, tumor size, nodal status, quantitative expression of estrogen and HER-2 receptor mRNA, and HER-2 gene copy number showed no correlation with pCR. Results of gene set enrichment analysis suggested that the lower expression of genes involved with CD40 signaling is associated with a greater risk of residual cancer after the preoperative chemotherapy that includes trastuzumab.

CONCLUSION

CD40 signaling may play a role in determining response to trastuzumab-plus-T/FEC therapy in patients with HER-2-overexpressing breast cancer.

Preclinical pharmacokinetics, pharmacodynamics, and activity of a humanized anti-CD40 antibody (SGN-40) in rodents and non-human primates

1. Cell-surface expression of CD40 in B-cell malignancies and multiple solid tumors has raised interest in its potential use as a target for antibody-based cancer therapy. SGN-40, a humanized monoclonal anti-CD40 antibody, mediates antibody-dependent cytotoxicity and inhibits B-cell tumor growth in vitro, properties of interest for the treatment of cancers, and is currently in Phase I clinical trials for B-cell malignancies. In this study, we determined in vivo activity and pharmacokinetics properties of SGN-40. 2. Effect of SGN-40 in xenograft model of CD40-expressing B-cell lymphoma in severe-combined immune deficiency mice and its in vivo pharmacokinetics properties in normal mice, rats and cynomolgus monkeys were studied. 3. Treatment with SGN-40 significantly increased the survival of mice xenografted with human B-cell lymphoma cell line. SGN-40 exhibited nearly 100% bioavailability in mice and it cleared faster when given at a low dose. In monkeys, clearance of SGN-40 was also much faster at low dose, suggesting nonlinear pharmacokinetics in these species. In rats, however, SGN-40 clearance at all tested doses was similar, suggesting that pharmacokinetics were linear in this dose range in rats. Administration of SGN-40 to monkeys also produced marked, dose-dependent, and persistent depletion of peripheral CD20(+) B lymphocytes. 4. Data presented in this report suggest that SGN-40 is active in in vivo, and based upon interspecies scaling, SGN-40 clearance in humans is predicted to be similar to observed SGN-40 clearance in monkeys. These data suggest that SGN-40 has appropriate pharmacokinetic properties that support its clinical use.

Chemotherapeutic agents enhance AAV2-mediated gene transfer into breast cancer cells promoting CD40 ligand-based immunotherapy

PURPOSE

Supplementing conventional treatment with gene therapy to induce an immune response might be beneficial to cancer patients. In this study, we evaluated the efficiency of transduction of breast cancer cells with recombinant adeno-associated virus (rAAV) and effects of cytotoxic agents used in chemotherapy. Furthermore, the capacity of tumor cells expressing transgenic CD40 ligand (CD40L) to stimulate dendritic cells was measured.

METHODS

Breast cancer cell lines were infected with a rAAV encoding the enhanced green fluorescent protein (EGFP) or murine CD40L and transgene expression was analyzed by flow cytometry. Stimulation of isolated human dendritic cells by CD40L-expressing tumor cells was quantified by measuring secreted interleukin 12.

RESULTS

Infection with an EGFP-encoding rAAV resulted in variable fractions (14-93%, mean 42%) of transgene-expressing cells. Pre-incubation of MM 157, MM 231, and MCF7 cells with epirubicin or carboplatin substantially increased AAV-mediated transgene expression. rAAV/CD40L was used to generate CD40L-transgenic tumor cells, which specifically activated immature dendritic cells, as confirmed by blocking with an antibody binding to CD40L.

CONCLUSIONS

The efficiency of rAAV-mediated gene transfer into breast cancer cells is significantly higher than previously reported and can be further enhanced by co-administration of chemotherapeutic agents. We also confirmed that breast cancer cells can activate human dendritic cells after infection with a CD40L-encoding rAAV.

CD40L induces multidrug resistance to apoptosis in breast carcinoma and lymphoma cells through caspase independent and dependent pathways

BACKGROUND

CD40L was found to reduce doxorubicin-induced apoptosis in non Hodgkin's lymphoma cell lines through caspase-3 dependent mechanism. Whether this represents a general mechanism for other tumor types is unknown.

METHODS

The resistance induced by CD40L against apoptosis induced by a panel of cytotoxic chemotherapeutic drugs in non Hodgkin's lymphoma and breast carcinoma cell lines was investigated.

RESULTS

Doxorubicin, cisplatyl, etoposide, vinblastin and paclitaxel increased apoptosis in a dose-dependent manner in breast carcinoma as well as in non Hodgkin's lymphoma cell lines. Co-culture with irradiated L cells expressing CD40L significantly reduced the percentage of apoptotic cells in breast carcinoma and non Hodgkin's lymphoma cell lines treated with these drugs. In breast carcinoma cell lines, these 5 drugs induced an inconsistent increase of caspase-3/7 activity, while in non Hodgkin's lymphoma cell lines all 5 drugs increased caspase-3/7 activity up to 28-fold above baseline. Co-culture with CD40L L cells reduced (-39% to -89%) the activation of caspase-3/7 induced by these agents in all 5 non Hodgkin's lymphoma cell lines, but in none of the 2 breast carcinoma cell lines. Co culture with CD40L L cells also blocked the apoptosis induced by exogenous ceramides in breast carcinoma and non Hodgkin's lymphoma cell lines through a caspase-3-like, 8-like and 9-like dependent pathways.

CONCLUSION

These results indicate that CD40L expressed on adjacent non tumoral cells induces multidrug resistance to cytotoxic agents and ceramides in both breast carcinoma and non Hodgkin's lymphoma cell lines, albeit through a caspase independent and dependent pathway respectively.

A functional CD40 receptor is expressed in pancreatic beta cells

AIMS/HYPOTHESIS

Despite differences in function and embryonic origin, pancreatic islet cells and neurons express proteins belonging to the tumour necrosis factor receptor superfamily. While neurons express the CD40 receptor, it is unknown whether islet cells also express it. We investigated CD40 expression in human and mouse pancreatic islets as well as in NIT-1 insulinoma cells.

METHODS

CD40 expression was studied by reverse transcriptase polymerase chain reaction, flow cytometry, immunohistochemistry and western blot. Responses mediated by CD40 were assessed by a luciferase gene reporter assay following stimulation with a CD40 agonist antibody.

RESULTS

We found that CD40 is expressed in mouse and human pancreatic islet cells. CD40 is expressed by beta cells, and its expression is upregulated by proinflammatory cytokines (IL-1beta, IFN-gamma and TNF-alpha). CD40 signalling in NIT-1 insulinoma cells activates nuclear factor kappa-B, demonstrating that CD40 is functional.

CONCLUSIONS/INTERPRETATION

We present evidence that, in addition to immune cell types, mouse and human pancreatic beta cells express CD40. Its expression is upregulated by proinflammatory stimuli, and signalling through this receptor activates NF-kappaB. We suggest that the effects of inflammatory stimuli that affect beta cell function and survival may be also mediated by signalling through the CD40 receptor. Thus, CD40 may have a role in processes associated with islet autoimmunity and transplantation.

Paclitaxel treatment of breast cancer cell lines modulates Fas/Fas ligand expression and induces apoptosis which can be inhibited through the CD40 receptor

OBJECTIVE

Cytotoxic chemotherapy of advanced breast cancer is frequently complicated by drug resistance. Our goal was to define the role of the apoptosis-regulating receptors Fas (CD95) and CD40 in the chemosensitivity of breast cancer.

METHODS

The sensitivity of four breast cancer cell lines to paclitaxel and mitoxantrone was evaluated using an ATP-based cell viability assay. After verification of apoptosis by annexin V staining and TUNEL assay, cell lines were characterized regarding their constitutive expression of both surface and soluble (s)Fas (CD95) and Fas ligand (Fas-L). The role of the Fas/Fas-L system and different caspases was assessed by blocking drug-mediated apoptosis with specific antibodies. Finally, the paclitaxel sensitivity of the CD40-negative cell line KS was compared to that of its CD40-positive transfectant KS-CD40.

RESULTS AND CONCLUSION

While the cytotoxic effect of mitoxantrone did not correlate with Fas expression, the results presented here suggest some involvement of the Fas/Fas-L system in paclitaxel-induced apoptosis. Cell lines with constitutive expression of Fas/sFas demonstrated a higher sensitivity to paclitaxel than Fas-negative cells. Incubation with paclitaxel led to a measurable downregulation of the expression of both soluble and surface Fas receptor in these cells. Interestingly, stimulation of the CD40 receptor inhibited paclitaxel-induced apoptosis in the transfected cell line KS-CD40, suggesting a role of this receptor in the modulation of chemosensitivity.

Prognostic Value of CD40 in Adult Soft Tissue Sarcomas

PURPOSE

The purpose is to evaluate the expression of CD40, a membrane protein predominantly expressed on B cells, dendritic cells, and macrophages, in a series of adult soft tissue sarcomas and to test its possible prognostic value.

EXPERIMENTAL DESIGN

CD40 expression was studied by immunohistochemistry. Correlations with other baseline characteristics of patients and tumors were analyzed with chi(2) test. The prognostic value was studied with univariable and multivariable analysis adjusted by age, sex, tumor size, grade, location, and distant metastases.

RESULTS

Eighty-two patients, between January 1994 and May 2001, were analyzed. Membrane or cytoplasmic staining for CD40 protein was absent in 30% of the tumors but present in <10% of cells in 22 (27%), in 10% to 50% in 23 (28%), and in >50% of cells in 12 (15%) tumors. There was no correlation between CD40 expression and age, sex, size, grade, and location of the primary tumor and distant metastases. With 61 patients (74.4%) progressed and 31 (37.8%) dead, CD40 expression was a significant prognostic factor for disease-free and overall survival at univariable and multivariable analysis. Patients with tumors expressing CD40 in >50% of cells had a dramatically unfavorable prognosis with median disease-free and overall survival of 7 and 17 months, respectively, and hazard ratios of relapse and death as compared with patients with CD40-negative tumors of 2.89 (95% confidence interval: 1.26-6.60) and 6.92 (95% confidence interval: 2.18-22.0), respectively.

CONCLUSIONS

These data suggest that expression of CD40 protein in >50% of cells might indicate an unfavorable prognosis in adult soft tissue sarcomas.

Vinorelbine and Cisplatin for Metastatic Breast Cancer: A Salvage Regimen in Patients Progressing After Docetaxel and Anthracycline Treatment

PURPOSE

To assess the antitumor efficacy and safety of a combination of vinorelbine (VNR) and cisplatin in patients with metastatic breast cancer previously treated with anthracyclines and docetaxel.

PATIENTS AND METHODS

Thirty-six patients with assessable metastatic breast cancer previously treated with anthracyclines and docetaxel (adjuvant n = 1, palliative n = 20, both n = 15) were studied. Cisplatin was given at 75 mg/m2 on day 1 followed by 25 mg/m2 VNR on days 1 + 8 in a 5-minute i.v. infusion. Courses were repeated every 3 weeks. Treatment was continued until disease progression, excess toxicity, or patient refusal. Patients were classified according to their response to anthracyclines according to criteria published previously: 1) Anthracycline and/or docetaxel resistant were patients who progressed during treatment with anthracyclines and docetaxel or within 4 months after cessation of treatment (metastatic). In addition, adjuvant patients who progressed within 6 months after completion of chemotherapy belong to this group. 2) Anthracycline and/or docetaxel relapsed were either metastatic patients who responded initially and then progressed after 4 months of completing an anthracycline- and docetaxel-based chemotherapy or patients who progressed after 6 months from completion of anthracycline/docetaxel-based adjuvant chemotherapy.

RESULTS

Two patients (5.6%) achieved a complete response (CR) and 15 patients (41.6%) achieved a partial response (PR), for an overall response rate (OR) of 47.2% (95% confidence interval, 31-63). Of 18 patients relapsed to anthracycline/docetaxel, 2 had a CR (11%) and 8 a PR (44.4%), giving an objective response of 55.5%. Stable disease (SD) was observed in one patient (5.5%); seven patients had progressive disease (PD) (39%). Among the 18 resistant patients, 7 PRs (39%) were observed (p = 0.5), one patient (5.5%) had stable disease, 10 patients (55.5%) progressed. The median time to progression (TTP) was 16 weeks and median overall survival 36 weeks. Relapsed patients had a longer TTP than resistant patients (24 vs. 8 weeks, p = 0.05) but similar survival (48 vs. 24 weeks, p = 0.173). All patients were assessed for toxicity. The main toxicity was neutropenia grade 3 and 4 in 47% of patients. Febrile neutropenia requiring hospitalization was absent. There were no treatment-related deaths. Thrombocytopenia grade 3 and 4 occurred in four patients (11%). Phlebitis, orthostatic hypotension, and asthenia, all reversible, were observed in 3% of patients, respectively.

CONCLUSION

This cisplatin/VNR regimen is well tolerated and active in patients who failed anthracyclines and docetaxel treatment. The response rate, TTP, and survival data are high and indicate that cisplatin/VNR may have a place as salvage treatment in this group of patients. If these results can be verified in multi-institutional trials, this combination of drugs would merit investigation as part of a first-line therapy in breast cancer.

Genetically targeted adenovirus vector directed to CD40-expressing cells

The success of gene therapy depends on the specificity of transgene delivery by therapeutic vectors. The present study describes the use of an adenovirus (Ad) fiber replacement strategy for genetic targeting of the virus to human CD40, which is expressed by a variety of diseased tissues. The tropism of the virus was modified by the incorporation into its capsid of a protein chimera comprising structural domains of three different proteins: the Ad serotype 5 fiber, phage T4 fibritin, and the human CD40 ligand (CD40L). The tumor necrosis factor-like domain of CD40L retains its functional tertiary structure upon incorporation into this chimera and allows the virus to use CD40 as a surrogate receptor for cell entry. The ability of the modified Ad vector to infect CD40-positive dendritic cells and tumor cells with a high efficiency makes this virus a prototype of choice for the derivation of therapeutic vectors for the genetic immunization and targeted destruction of tumors.

Heterogeneous expression and regulation of CD40 in human hepatocellular carcinoma

OBJECTIVE

CD40, a member of the tumour necrosis factor receptor family, plays a major role in adaptive immune responses and contributes to cancer surveillance. Conflicting results have been reported recently on the expression and function of CD40 in carcinomas. The aim of the present study was to investigate the role of CD40 in human hepatoma.

DESIGN/METHODS

CD40 expression was examined in hepatomas and derived cell lines by immunohistochemistry, flow cytometry and reverse transcriptase polymerase chain reaction. We investigated in hepatoma cell lines the regulation of CD40 by pro-inflammatory cytokines and the effects of its ligation with soluble CD40L on the expression of co-stimulatory and pro-apoptotic cell-surface molecules and survival.

RESULTS

CD40 was detected with a similar frequency of about 40% in hepatoma specimens and derived cell lines but not in normal hepatocytes. Tumour necrosis factor alpha and its combination with interferon gamma upregulated CD40 only in intrinsically positive cell lines. CD40 ligation had no effect on cell viability or surface expression of CD54, CD80, CD86 or CD95.

CONCLUSIONS

CD40 is expressed variably in human hepatoma and enhanced by distinct pro-inflammatory cytokines. The lack of detectable effects of CD40 ligation does not support a major role of this molecule in hepatocellular carcinoma biology.

Prospects for CD40-directed experimental therapy of human cancer

CD40, a member of the tumor necrosis factor receptor (TNF-R) family, is a surface receptor best known for its capacity to initiate multifaceted activation signals in normal B cells and dendritic cells (DCs). CD40-related treatment approaches have been considered for the experimental therapy of human leukemias, lymphomas, and multiple myeloma, based on findings that CD40 binding by its natural ligand (CD40L), CD154, led to growth modulation of malignant B cells. Recent studies also exploited the selective expression of the CD40 receptor on human epithelial and mesenchymal tumors but not on most normal, nonproliferating epithelial tissues. Ligation of CD40 on human breast, ovarian, cervical, bladder, non small cell lung, and squamous epithelial carcinoma cells was found to produce a direct growth-inhibitory effect through cell cycle blockage and/or apoptotic induction with no overt side effects on their normal counterparts. CD154 treatment also heightened tumor rejection immune responses through DC activation, and by increasing tumor immunogenicity through up-regulation of costimulatory molecule expression and cytokine production of epithelial cancer cells. These immunopotentiating features can produce a "bystander effect" through which the CD40-negative tumor subset is eliminated by activated tumor-reactive cytotoxic T cells. However, the potential risk of systemic inflammation and autoimmune consequences remains a concern for systemic CD154-based experimental therapy. The promise of CD154 as a tumor therapeutic agent to directly modulate tumor cell growth, and indirectly activate antitumor immune response, may depend on selective and/or restricted CD154 expression within the tumor microenvironment. This may be achieved by inoculating cancer vaccines of autologous cancer cells that have been transduced ex vivo with CD154, as documented by recently clinical trials. This review summarizes recent findings on CD154 recombinant protein- and gene therapy-based tumor treatment approaches, and examines our understanding of the multifaceted molecular mechanisms of CD154-CD40 interactions.

A phase II study of dose-dense docetaxel and mitoxantrone in the treatment of patients with high-risk metastatic breast cancer

Doxetaxel (DCT) and mitoxantrone (MX) are highly active and potentially synergistic agents in the treatment of metastatic breast cancer (MBC). This pilot study evaluates the combination of dose-dense DCT and MX in patients with MBC to determine the efficacy and toxicity of this therapy. Thirty-six patients (56.1+/-1.7 years) were studied. The patients received DCT (35 mg/m(2) q1w) and MX (6 mg/m(2) q2w) for 6 weeks of an 8-week interval. Patients with tumor response or stable disease (SD) continued the treatment for a maximum of two additional periods. Hematologic and non-hematologic parameters were determined using the WHO common toxicity score. During this study 14 patients (40%) experienced partial response, 14 (40%) SD. In 20% of the cases the disease progressed on therapy. The treatment with DCT and MX was well tolerated. Seventeen patients (47%) experienced grade 3 leukopenia. Other hematologic and non-hematologic side effects did not exceed grade 2. One patient died during therapy because of a pulmonary embolism, which was unlikely related to active agents. Dose-dense DCT and MX combines both clinical activity and convenience for the patient. Therefore, we conclude that this regimen is a promising therapy in MBC, which warrants confirmation by large-scale clinical trials.

Epirubicin--docetaxel combination in first-line chemotherapy for patients with metastatic breast cancer: final results of a dose-finding and efficacy study

The aim of the study was to define a regular and tolerable dose of the epirubicin-docetaxel combination in first-line chemotherapy of patients with metastatic breast cancer. Sixty-five women with measurable and/or evaluable disease were treated with epirubicin escalated from 60 to 110 mg/m(2) according to 5 dose levels, in combination with a fixed dose of 75 mg/m(2) docetaxel, every 21 days for 6 cycles, without preventive use of hematopoietic growth factors or antibiotics. Forty-three women received adjuvant chemotherapy, consisting of anthracyline- or anthracenedione-based regimens in 39 cases (60%). Twenty-seven women were treated in the phase I study (3 at epirubicin 60 mg/m(2), and 6 at each subsequent dose level). Dose-limiting toxicity consisted of grade III asthenia and febrile neutropenia (epirubicin 75 mg/m(2)), grade IV thrombopenia and grade III asthenia (epirubicin 90 mg/m(2)), grade IV stomatitis and grade III diarrhea (epirubicin 100 mg/m(2)), and grade III diarrhea (epirubicin 110 mg/m(2)). In the phase II study, an additional 38 women were treated at epirubicin 90 mg/m(2) and epirubicin 100 mg/m(2). During the 349 cycles delivered, grade IV neutropenia occurred in 90%; febrile neutropenia requiring hospitalization occurred in 62 (17.8%) and lasted more than 3 days in 12 (3.4%). Nonhematologic toxicity was acceptable. Three left ventricular ejection fraction depressions occurred and normalized during follow-up. The overall response rate in the 62 evaluable women was 69.4% (range: 58--81%), with a median duration of 7.8 months. After 26 months of follow-up, the median time to progression was 9.1 months and median overall survival was 22.7 months. On the basis of efficacy and toxicity, the recommended dose of the combination is epirubicin 100 mg/m(2) plus docetaxel 75 mg/m(2).

Phase I study of recombinant human CD40 ligand in cancer patients

PURPOSE

To determine the toxicity, maximum-tolerated dose (MTD), and pharmacokinetics of recombinant human CD40 ligand (rhuCD40L) (Avrend; Immunex Corp, Seattle, WA), suggested in preclinical studies to mediate cytotoxicity against CD40-expressing tumors and immune stimulation.

PATIENTS AND METHODS

Patients with advanced solid tumors or intermediate- or high-grade non-Hodgkin's lymphoma (NHL) received rhuCD40L subcutaneously daily for 5 days in a phase I dose-escalation study. Subsequent courses were given until disease progression.

RESULTS

Thirty-two patients received rhuCD40L at three dose levels. A total of 65 courses were administered. The MTD was 0.1 mg/kg/d based on dose-related but transient elevations of serum liver transaminases. Grade 3 or 4 transaminase elevations occurred in 14%, 28%, and 57% of patients treated at 0.05, 0.10, and 0.15 mg/kg/d, respectively. Other toxicities were mild to moderate. At the MTD, the half-life of rhuCD40L was calculated at 24.8 +/- 22.8 hours. Two patients (6%) had a partial response on study (one patient with laryngeal carcinoma and one with NHL). For the patient with laryngeal cancer, a partial response was sustained for 12 months before the patient was taken off therapy and observed on no additional therapy. Three months later, the patient was found to have a complete response and remains biopsy-proven free of disease at 24 months. Twelve patients (38%) had stable disease after one course, which was sustained in four patients through four courses.

CONCLUSION

The MTD of rhuCD40L when administered subcutaneously daily for 5 days was defined by transient serum elevations in hepatic transaminases. Encouraging antitumor activity, including a long-term complete remission, was observed. Phase II studies are warranted.

CD40 is not detected on human prostate cancer cells by immunohistologic techniques

OBJECTIVES

The CD40 antigen is expressed by antigen-presenting cells, many kinds of epithelium, and carcinomas. As signaling through CD40 modulates the differentiation state of CD40-expressing cells, we wanted to investigate whether benign or malignant prostate epithelium expressed CD40.

METHODS

Twenty-two paraffin-embedded and 10 snap-frozen human prostate tissue samples were analyzed by immunohistologic methods, using the basal cell-specific markers, high molecular weight cytokeratin (HMWCK) and keratin-14 (K14), and the luminal cell marker, low molecular weight cytokeratin (LMWCK), together with CD40. Fresh prostate tissue was cultured in vitro and analyzed by immunocytofluorescence.

RESULTS

The pattern of CD40 expression was continuous on basal epithelial cells of normal and hyperplastic prostate glands but discontinuous in glands that featured prostatic intraepithelial neoplasia. Coexpression of CD40 with the basal cell-specific cytokeratins, HMWCK and K14, was confirmed by double labeling. In contrast, glandular epithelial cells in prostate adenocarcinoma did not express CD40 or these cytokeratins. A luminal cell phenotype defined as CAM5.2-positive and HMWCK-negative K14-negative was identified among primary epithelial cells cultured in vitro. Most of the cultured cells (more than 99%) were also CD40-negative.

CONCLUSIONS

Together, our results support the hypothesis that CD40 expression correlates with the basal cell phenotype, which is lost upon malignant transformation of the prostate. Hence, CD40 may be useful diagnostically to distinguish benign from malignant prostate lesions in biopsy material.

Treatment of advanced, refractory breast cancer with alternating docetaxel and epirubicin/cyclophosphamide plus human granulocyte colony-stimulating factor

PURPOSE

A phase II study was performed to investigate the efficacy and tolerance of alternating docetaxel and epirubicin/cyclophosphamide plus recombinant human granulocyte colony-stimulating factor (G-CSF) in patients with advanced breast cancer who failed previous non-anthracycline/taxane-containing palliative chemotherapy.

PATIENTS AND METHODS

Between November 96 and June 98, a total of 45 patients participated in this trial. Chemotherapy consisted of docetaxel 100 mg/m2 given as a 1-h infusion on day 1, and epirubicin 100 mg/m2 plus cyclophosphamide 800 mg/m2 both administered on day 21. G-CSF 5 microg/kg/day was given subcutaneously from days 22-28 during each cycle. Treatment courses were repeated every 42 days for a total of three courses unless prior evidence of progressive disease.

RESULTS

The overall response rate was 57.8% (95% confidence interval, 42.1-72.3%), including seven complete (15.5%) and 19 partial remissions (42.3%); nine patients (20%) had stabilization of disease and 10 (22.3%) progressed. The median time to treatment failure was 7.0 months (range 1.5-26.0), and the median overall survival time 15.0 months (range 2.0-37.0+) with 12 patients (27%) currently still alive with metastatic disease. Myelosuppression was commonly observed with WHO grade 3/4 neutropenia in 20 patients (44%) complicated by septicemia in five (11%). Severe nonhematologic toxicity included stomatitis in five patients (11%), skin and peripheral neurotoxicity each in one patient; alopecia was seen in all 45 patients with complete hair loss in 26 (58%).

CONCLUSIONS

Our data suggest that alternating docetaxel and epirubicin/cyclo-phosphamide plus G-CSF is an effective and tolerable second-line combination regimen for the treatment of advanced breast cancer.

CD40 expressed on human melanoma cells mediates T cell co-stimulation and tumor cell growth

CD40 is a 50 kDa molecule, a member of the tumor necrosis factor/nerve growth factor receptor family. It is expressed on B cells, monocytes, dendritic cells and various malignant cells. While the critical relevance of this molecule in T cell-dependent B cell activation is already established, the biological role of CD40-CD154 interaction in non-hematopoietic cells is still unknown. Here we show that CD40 is functionally expressed on human melanoma-derived cell lines. No correlation between surface CD40 expression and the origin of the cell line, primary versus metastatic, was observed. Melanoma cells were shown to be able to co-stimulate TCR-triggered human T cells; moreover, because they do not express CD80 or CD86 co-stimulatory structures, the involvement of additional pathways have to be postulated. We have identified CD40 as one of the molecules involved in melanoma cell-mediated co-stimulation of anti-CD3-triggered human CD4(+) T lymphocytes. In addition, a CD40-dependent pathway, able to enhance tumor cell proliferation at low serum concentrations, in vitro, has been shown to be functional in human melanoma cell lines.

Expression of functional CD40 in human hepatocellular carcinoma

CD40, a member of the tumor necrosis factor receptor (TNFR) family, plays a crucial role in the survival, proliferation, and differentiation in B cells. However, the expression of CD40 other than in B cells has not been well studied. Therefore, we investigated the expression and function of CD40 in hepatocellular carcinomas (HCCs). Expression of CD40 mRNA in 6 established HCC cell lines was analyzed by reverse-transcription polymerase chain reaction (RT-PCR) and CD40 expression on cell surface was examined by flow cytometrical analysis. We also examined the expression of CD40 in human HCC tissues (45 cases) and nontumor liver tissues (30 cases) by immunohistochemistry. To examine the function of CD40 in HCC cells, we investigated the effect of CD40 signaling on anti-Fas antibody and TNF-alpha-induced apoptosis in HepG2 cells. In addition, intracellular levels of cysteine protease P32 (CPP32) protein in HepG2 cells were also determined by Western blotting. We have shown that 6 HCC cell lines constitutively expressed CD40 mRNA and membrane-bound CD40 antigen, which was slightly up-regulated by interferon gamma (IFN-gamma). In addition, 60% of human HCC tissues demonstrated positive staining for CD40, whereas nontumor tissues showed little detectable staining. In HepG2 cells, CD40 stimulation does not affect cell viability, but significantly inhibited Fas and TNFR-mediated apoptosis in a dose-dependent manner by blocking the activation of CPP32. From these results, we conclude that CD40 expression in HCCs plays an important role in tumor biology, especially the resistance against Fas and TNFR-mediated apoptosis.