Identification of unanimous immune subtypes for different hormone receptor phenotypes of human breast cancer with potential prognostic significance.

The immunogenicity of the breast tumor microenvironment is clinically heterogeneous. The insight into the role of tumor-infiltrating lymphocytes (TILs) might serve as a biomarker to predict a survival benefit and enable optimal patient selection for immunotherapy. In this study, we aimed at characterizing the breast cancer immune subtypes linked to CD8 T cells and associating with the patient characteristics and clinical outcomes. We analyzed the immune gene signatures of human breast cancer using The Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) database profiling of 1092 breast tumor patients. We performed hierarchical clustering to the immune gene expression by applying hormone receptor status including triple negative breast cancer to categorize 66 immune-related genes in breast tumors. The separation was characterized by dividing the breast tumors into two major immune subtypes: predominant immune (PI) subtype and low immune subtype (LI). Our results showed that both PI and LI subtypes can be observed in the different hormone receptor phenotypes of breast tumors, and PI subtype accounted for 16% and LI subtype 20% in the breast tumor patients. The estimated odds for LI subtype breast tumors were significantly higher than PI subtype breast tumors in primary tumor stages. Our data demonstrated that the PI subtype breast tumors have significantly improved survival compared with LI subtype. Our findings provide a novel perspective of breast cancer immune subtypes linked to CD8 T cells. The immune subtypes will be a valuable resource for future research to identify clinically relevant biomarkers for precision immunotherapy.

Complement--tapping into new sites and effector systems.

Complement is traditionally known to be a system of serum proteins that provide protection against pathogens through direct cell lysis and the mobilization of innate and adaptive immunity. However, recent work indicates that the complement system has additional physiological roles beyond those in host defence. In this Opinion article, we describe the new modes and locations of complement activation that enable it to interact with other cell effector systems, such as growth factor receptors, inflammasomes and metabolic pathways. We propose that the location of complement activation dictates its function.

Antibodies against growth factor receptors can inhibit the proliferation of transformed cells via a cis-interaction with inhibitory FcR.

When dimerized by Stem Cell Factor (SCF), the Receptor Tyrosine Kinase Kit triggers the proliferation of hematopoietic progenitors, including pro-B cells, and of some differentiated cells, including mast cells. We found previously that anti-Kit antibodies can mimic SCF and that anti-Kit-induced mast cell proliferation can be inhibited by the low-affinity IgG receptors FcγRIIB, when the two receptors are co-aggregated by IgG immune complexes. We show here that the same immune complexes inhibited anti-Kit-induced proliferation of Ba/F3 pro-B cells expressing wt Kit and FcγRIIB and that inhibition required the intracytoplasmic domain of FcγRIIB. Constitutively active Kit mutants are oncogenic. We show that Kit-dependent, ligand-independent proliferation of Ba/F3 cells expressing a constitutively dimerized Kit mutant was also inhibited by IgG immune complexes via FcγRIIB. FcγRIIB-dependent negative regulation therefore also affects Kit-dependent proliferation of transformed cells. Interestingly, the co-aggregation of Kit with FcγRIIB by immune complexes containing SCF also inhibited both growth factor-dependent and growth factor-independent proliferation of Ba/F3 cells expressing wt or mutated Kit, respectively. These results provide the basis for novel immunotherapeutical approaches of FcγRIIB-expressing tumors.

Distinct localization of T cell Agrin during antigen presentation--evidence for the expression of Agrin receptor(s) in antigen-presenting cells.

Agrin is over-expressed by activated and autoimmune T cells, and synergizes with the T cell receptor (TCR) to augment cell activation. In the present study, we show that Agrin accumulates to distinct areas of the plasma membrane and that cell activation causes its redistribution. During antigen presentation, Agrin primarily accumulates to the periphery of the mature immunological synapse, mostly in lamellipodia-like protrusions that wrap around the antigen-presenting cell and, conversely, anti-Agrin sera induced a significant redistribution of TCR at the plasma membrane. We also provide evidence for the expression of Agrin receptors in peripheral blood monocytes, dendritic cells and a fraction of B cells. Interestingly, interferon-α treatment, which induces the expression of Agrin in T cells, also augmented Agrin binding to monocytes. Stimulation of monocytes with recombinant Agrin induced the clustering of surface receptors, including major histocompatibility complex class II, activation of intracellular signalling cascades, as well as enhanced dsRNA-induced expression of pro-inflammatory cytokines interleukin-6 and tumour necrosis factor-α. Collectively, these results confirm the location of Agrin at the immunological synapse between T cells and antigen-presenting cells and justify further characterization of its receptors in the immune system.

The cytokine midkine and its receptor RPTPζ regulate B cell survival in a pathway induced by CD74.

Lasting B cell persistence depends on survival signals that are transduced by cell surface receptors. In this study, we describe a novel biological mechanism essential for survival and homeostasis of normal peripheral mature B cells and chronic lymphocytic leukemia cells, regulated by the heparin-binding cytokine, midkine (MK), and its proteoglycan receptor, the receptor-type tyrosine phosphatase ζ (RPTPζ). We demonstrate that MK initiates a signaling cascade leading to B cell survival by binding to RPTPζ. In mice lacking PTPRZ, the proportion and number of the mature B cell population are reduced. Our results emphasize a unique and critical function for MK signaling in the previously described MIF/CD74-induced survival pathway. Stimulation of CD74 with MIF leads to c-Met activation, resulting in elevation of MK expression in both normal mouse splenic B and chronic lymphocytic leukemia cells. Our results indicate that MK and RPTPζ are important regulators of the B cell repertoire. These findings could pave the way toward understanding the mechanisms shaping B cell survival and suggest novel therapeutic strategies based on the blockade of the MK/RPTPζ-dependent survival pathway.

Identification of target antigens of anti-endothelial cell and anti-vascular smooth muscle cell antibodies in patients with giant cell arteritis: a proteomic approach.

INTRODUCTION: Immunological studies of giant cell arteritis (GCA) suggest that a triggering antigen of unknown nature could generate a specific immune response. We thus decided to detect autoantibodies directed against endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) in the serum of GCA patients and to identify their target antigens. METHODS: Sera from 15 GCA patients were tested in 5 pools of 3 patients' sera and compared to a sera pool from 12 healthy controls (HCs). Serum immunoglobulin G (IgG) reactivity was analysed by 2-D electrophoresis and immunoblotting with antigens from human umbilical vein ECs (HUVECs) and mammary artery VSMCs. Target antigens were identified by mass spectrometry. RESULTS: Serum IgG from GCA patients recognised 162 ± 3 (mean ± SD) and 100 ± 17 (mean ± SD) protein spots from HUVECs and VSMCs, respectively, and that from HCs recognised 79 and 94 protein spots, respectively. In total, 30 spots from HUVECs and 19 from VSMCs were recognised by at least two-thirds and three-fifths, respectively, of the pools of sera from GCA patients and not by sera from HCs. Among identified proteins, we found vinculin, lamin A/C, voltage-dependent anion-selective channel protein 2, annexin V and other proteins involved in cell energy metabolism and key cellular pathways. Ingenuity pathway analysis revealed that most identified target antigens interacted with growth factor receptor-bound protein 2. CONCLUSIONS: IgG antibodies to proteins in the proteome of ECs and VSMCs are present in the sera of GCA patients and recognise cellular targets that play key roles in cell biology and maintenance of homeostasis. Their potential pathogenic role remains to be determined.

Midkine in inflammation.

The 13 kDa heparin-binding growth factor midkine (MK) was originally identified as a molecule involved in the orchestration of embryonic development. Recent studies provided evidence for a new role of MK in acute and chronic inflammatory processes. Accordingly, several inflammatory diseases including nephritis, arthritis, atherosclerosis, colitis, and autoimmune encephalitis have been shown to be alleviated in the absence of MK in animal models. Reduced leukocyte recruitment to the sites of inflammation was found to be one important mechanism attenuating chronic inflammation when MK was absent. Furthermore, MK was found to modulate expression of proinflammatory cytokines and the expansion of regulatory T-cells. Here, we review the current understanding of the role of MK in different inflammatory disorders and summarize the knowledge of MK biology.

Antibodies to watch in 2010.

Monoclonal antibodies (mAbs) are a burgeoning class of therapeutics, with more than 25 approved in countries worldwide. Novel molecules are entering clinical study at a rate of nearly 40 per year, and the commercial pipeline includes approximately 240 mAb therapeutics in clinical studies that have not yet progressed to regulatory approval or been approved. Of particular interest are the 26 mAbs that are currently at Phase 3, when safety and efficacy data critical to approval is established. Phase 3 study lengths are typically two to four years, so results for some studies might be announced in 2010, but data from others might not be presented until 2014. This overview of the 26 candidates provides a brief description of the background and the on-going Phase 3 studies of each mAb. Additional mAbs that have progressed to regulatory review or been approved may also be in Phase 3 studies, but these, as well as Fc fusion proteins, have been excluded. Due to the large body of primary literature about the 26 candidates, only selected references are given, with a focus on recent publications and articles that were relevant to Phase 3 studies. Current as of October 2009, the results presented here will serve as a baseline against which future progress can be measured.

[Role of the expression of c-Met receptor in the progression of gastric cancer]. / Papel de la expresión del receptor c-Met en la progresión del cancer gástrico.

The product of the proto-oncogene C-MET (the c-Met receptor) and its ligand, hepatocyte growth factor (HGF), have been implicated in the progression of gastric cancer. The aim of this study was to analyze the expression of c-Met receptor, HGF and proliferating cell nuclear antigen (PCNA) by the immunohistochemistry method of labeled streptavidin-biotin, as well as survival, and they were correlated with anatomopathological factors in stomach specimens of 40 patients, who underwent gastrectomy for gastric cancer in the Department of General Surgery, Hospital Central Universitario "Antonio María Pineda" in Barquisimeto, Venezuela, in 2001-2004. High expression of c-Met receptor and PCNA was observed in patients with advanced stages of gastric cancer (III and IV) compared with early stages (I and II) (p<0.01). There was also overexpression of the c-Met receptor in histologic variables with low degree of differentiation, deeper tumor invasion into the submucosa, liver metastases and it is reported a lower survival rate in patients with increased receptor expression (+++ and ++++) when compared with patients with the lowest expression (+ and ++) (p<0.01). The expression of HGF was constant in both, advanced and early groups. The c-Met receptor is associated with proliferation and cell migration in Venezuelan patients with gastric cancer and could be used as a prognostic factor in this pathology.

Discovery of fully human anti-MET monoclonal antibodies with antitumor activity against colon cancer tumor models in vivo.

The receptor tyrosine kinase MET is a major component controlling the invasive growth program in embryonic development and in invasive malignancies. The discovery of therapeutic antibodies against MET has been difficult, and antibodies that compete with hepatocyte growth factor (HGF) act as agonists. By applying phage technology and cell-based panning strategies, we discovered two fully human antibodies against MET (R13 and R28), which synergistically inhibit HGF binding to MET and elicit antibody-dependent cellular cytotoxicity. Cell-based phosphorylation assays demonstrate that R13 and R28 abrogate HGF-induced activation of MET, AKT1, ERK1/2, and HGF-induced migration and proliferation. FACS experiments suggest that the inhibitory effect is mediated by "locking" MET receptor in a state with R13, which then increases avidity of R28 for the extracellular domain of MET, thus blocking HGF binding without activating the receptor. In vivo studies demonstrate that the combination of R13/28 significantly inhibited tumor growth in various colon tumor xenograft models. Inhibition of tumor growth was associated with induction of hypoxia. Global gene expression analysis shows that inhibition of HGF/MET pathway significantly upregulated the tumor suppressors KLF6, CEACAM1, and BMP2, the negative regulator of phosphatidylinositol-3-OH-kinase PIK3IP1, and significantly suppressed SCF and SERPINE2, both enhancers of proliferation and invasiveness. Moreover, in an experimental metastasis model, R13/28 increased survival by preventing the recurrence of otherwise lethal lung metastases. Taken together, these results underscore the utility of a dual-antibody approach for targeting MET and possibly other receptor tyrosine kinases. Our approach could be expanded to drug discovery efforts against other cell surface proteins.

Genetic modification of natural killer cells for adoptive cellular immunotherapy.

Immunotherapy of cancer is a rapidly developing field; one such development is the manipulation and use of natural killer (NK) cells. These cells with 'killer instincts' are an attractive cell to utilize, as they are directly reactive toward tumor and could potentially activate the endogenous adaptive immune system. Their employment in adoptive cell transfer treatments has yielded important results and discoveries, although effective antitumor responses are limited. To address these limitations, NK cells are the target of a new generation of immunotherapy involving gene transfer. The gene modification of immune cells is a relatively recent technique and some groups have targeted NK cells for gene modification to improve their antitumor efficacy. This review will investigate studies describing the gene modification of NK cells and their encouraging antitumor effects.

The relative distribution of membranous and cytoplasmic met is a prognostic indicator in stage I and II colon cancer.

PURPOSE: The association hepatocyte growth factor receptor (Met) tyrosine kinase with prognosis and survival in colon cancer is unclear, due in part to the limitation of detection methods used. In particular, conventional chromagenic immunohistochemistry (IHC) has several limitations including the inability to separate compartmental measurements. Measurement of membrane, cytoplasm, and nuclear levels of Met could offer a superior approach to traditional IHC. EXPERIMENTAL DESIGN: Fluorescent-based IHC for Met was done in 583 colon cancer patients in a tissue microarray format. Using curvature and intensity-based image analysis, the membrane, nuclear, and cytoplasm were segmented. Probability distributions of Met within each compartment were determined, and an automated scoring algorithm was generated. An optimal score cutpoint was calculated using 500-fold crossvalidation of a training and test data set. For comparison with conventional IHC, a second array from the same tissue microarray block was 3,3'-diaminobenzidine immunostained for Met. RESULTS: In crossvalidated and univariate Cox analysis, the membrane relative to cytoplasm Met score was a significant predictor of survival in stage I (hazard ratio, 0.16; P = 0.006) and in stage II patients (hazard ratio, 0.34; P < or = 0.0005). Similar results were found with multivariate analysis. Met in the membrane alone was not a significant predictor of outcome in all patients or within stage. In the 3,3'-diaminobenzidine-stained array, no associations were found with Met expression and survival. CONCLUSIONS: These data indicate that the relative subcellular distribution of Met, as measured by novel automated image analysis, may be a valuable biomarker for estimating colon cancer prognosis.

Growth factor receptors and related signalling pathways as targets for novel treatment strategies of hepatocellular cancer.

Growth factors and their corresponding receptors are commonly overexpressed and/or dysregulated in many cancers including hepatocellular cancer (HCC). Clinical trials indicate that growth factor receptors and their related signalling pathways play important roles in HCC cancer etiology and progression, thus providing rational targets for innovative cancer therapies. A number of strategies including monoclonal antibodies, tyrosine kinase inhibitors ("small molecule inhibitors") and antisense oligonucleotides have already been evaluated for their potency to inhibit the activity and downstream signalling cascades of these receptors in HCC. First clinical trials have also shown that multi-kinase inhibition is an effective novel treatment strategy in HCC. In this respect sorafenib, an inhibitor of Raf-, VEGF- and PDGF-signalling, is the first multi-kinase inhibitor that has been approved by the FDA for the treatment of advanced HCC. Moreover, the serine-threonine kinase of mammalian target of rapamycin (mTOR) upon which the signalling of several growth factor receptors converge plays a central role in cancer cell proliferation. mTOR inhibition of HCC is currently also being studied in preclinical trials. As HCCs represent hypervascularized neoplasms, inhibition of tumour vessel formation via interfering with the VEGF/VEGFR system is another promising approach in HCC treatment. This review will summarize the current status of the various growth factor receptor-based treatment strategies and in view of the multitude of novel targeted approaches, the rationale for combination therapies for advanced HCC treatment will also be taken into account.

Potential therapeutic strategies for lymphatic metastasis.

Physiologically, the lymphatic system regulates fluid volume in the interstitium and provides a conduit for immune cells to travel to lymph nodes, but pathologically, the lymphatic system serves as a primary escape route for cancer cells. Lymphatic capillaries have a thin discontinuous basement membrane, lack pericyte coverage and often contain endothelial cell gaps that can be invaded by immune cells (or tumor cells). In addition, tumor cells and stromal cells in the tumor microenvironment secrete factors that stimulate lymphangiogenesis, the growth of lymphatic endothelial cells and the sprouting of lymphatic capillaries. As a result, many tumors are surrounded by large, hyperplastic, peri-tumoral lymphatic vessels and less frequently are invaded by intra-tumoral lymphatic vessels. Carcinoma cells commonly metastasize through these lymphatic vessels to regional lymph nodes. The presence of metastatic cells in the sentinel lymph node is a prognostic indicator for many types of cancer, and the degree of dissemination determines the therapeutic course of action. Lymphangiogenesis is currently at the frontier of metastasis research. Recent strides in this field have uncovered numerous signaling pathways specific for lymphatic endothelial cells and vascular endothelial cells. This review will provide an overview of tumor lymphangiogenesis and current strategies aimed at inhibiting lymphatic metastasis. Novel therapeutic approaches that target the tumor cells as well as the vascular and lymphatic endothelial compartments are discussed.

Monoclonal and bispecific antibodies as novel therapeutics.

Gene amplification, over-expression, and mutation of growth factors, or the receptors themselves, causes increased signaling through receptor kinases, which has been implicated in many human cancers and is associated with poor prognosis. Tumor growth has been shown to be decreased by interrupting this process of extensive growth factor-mediated signaling by directly targeting either the surface receptor or the ligand and thereby preventing cell survival and promoting apoptosis. Monoclonal antibodies have long been eyed as a potential new class of therapeutics targeting cancer and other diseases. Antibody-based therapy initially entered clinical practice when trastuzumab/Herceptin became the first clinically approved drug against an oncogene product as a well-established blocking reagent for tumors with hyperactivity of epidermal growth factor signaling pathways. In the first part of this review we explain basic terms related to the development of antibody-based drugs, give a brief historic perspective of the field, and also touch on topics such as the "humanization of antibodie" or creation of hybrid antibodies. The second part of the review gives an overview of the clinical usage of bispecific antibodies and antibodies "armed" with cytotoxic agents or enzymes. Further within this section, cancer-specific, site-specific, or signaling pathway-specific therapies are discussed in detail. Among other antibody-based therapeutic products, we discuss: Avastin (bevacizumab), CG76030, Theragyn (pemtumomab), daclizumab (Zenapax), TriAb, MDX-210, Herceptin (trastuzumab), panitumumab (ABX-EGF), mastuzimab (EMD-72000), Erbitux (certuximab, IMC225), Panorex (edrecolomab), STI571, CeaVac, Campath (alemtuizumab), Mylotarg (gemtuzumab, ozogamicin), and many others. The end of the review deliberates upon potential problems associated with cancer immunotherapy.

Agonist Met antibodies define the signalling threshold required for a full mitogenic and invasive program of Kaposi's Sarcoma cells.

We previously showed that the Kaposi Sarcoma line KS-IMM express a functional Met tyrosine kinase receptor, which, upon HGF stimulation, activates motogenic, proliferative, and invasive responses. In this study, we investigated the signalling pathways activated by HGF, as well as by Met monoclonal antibodies (Mabs), acting as full or partial agonists. The full agonist Mab mimics HGF in all biological and biochemical aspects. It elicits the whole spectrum of responses, while the partial agonist Mab induces only wound healing. These differences correlated with a more prolonged and sustained tyrosine phosphorylation of the receptor and MAPK evoked by HGF and by the full agonist Mab, relative to the partial agonist Mab. Since Gab1, JNK and PI 3-kinase are activated with same intensity and kinetics by HGF and by the two agonist antibodies, it is concluded that level and duration of MAPK activation by Met receptor are crucial for the induction of a full HGF-dependent mitogenic and invasive program in KS cells.

Oocyte-expressed genes affecting ovulation rate.

From examination of inherited patterns of ovulation rate in sheep, several breeds have been identified with point mutations in two growth factor genes (BMP15 and GDF9) and a related receptor (ALK6) that are expressed in oocytes. Five different point mutations have been identified in the BMP15 gene, one in GDF9 and one in ALK6. Animals heterozygous for these mutations or heterozygous for two of these mutations or homozygous for the ALK6 mutation have higher ovulation rates (i.e. +0.6-10) than their wild-type contemporaries. Animals homozygous for the BMP15 or GDF9 mutations are sterile due to arrested follicular development from the primary stage of growth. The BMP15 and GDF9 mutations are thought to result in reduced levels of mature protein or altered binding to cell-surface receptors. In sheep, GDF9 mRNA is present in germ cells before and after ovarian follicular formation as well as throughout follicular growth, whereas BMP15 mRNA is found in oocytes only from the primary stage of growth. Also ALK6 together with related cell-surface receptors such as ALK5 and BMPRII mRNA are present in oocytes at most, if not all, stages of follicular growth. Both GDF9 and BMP15 proteins are present in follicular fluid indicating that they are secreted products. Immunisation of sheep with GDF9 or BMP15 peptides shows that both growth factors are essential for follicular development, ovulation and/or corpus luteum formation. In animals with the ALK6 mutation, ovarian follicles undergo precocious maturation leading to three to seven follicles ovulating at smaller diameters without any increase above wild-types in the ovarian secretions of steroid or inhibin. One important consequence of the ALK6 mutation appears to be a decreased ability of some BMPs to inhibit differentiation of follicular cells. Current findings in sheep suggest that BMP15, GDF9 and ALK6 are targets for new methods of fertility regulation in some mammals.

Bone morphogenetic proteins are expressed by both bone-forming and non-bone-forming lesions.

CONTEXT: Bone morphogenetic proteins (BMPs) are thought to be responsible for bone formation; they cause bone to form in soft tissues and are clinically used in helping fracture union or tumor reconstructions. Skeletal metastases from epithelial tumors may be either bone-forming (blastic) or non-bone-forming (lytic). OBJECTIVE: We studied the expression of BMPs in a variety of primary and secondary lesions of bone (both bone-forming and non-bone-forming) to determine if there was a consistent relationship between bone formation and BMP expression. DESIGN: We compared a bone-forming lesion (fibrous dysplasia) with a non-bone-forming lesion (desmoid tumor), using reverse transcription-polymerase chain reaction, Northern blot analysis, and immunohistochemistry to detect BMPs. We also studied a number of non-bone-forming secondary lesions (carcinomas that formed lytic metastases to the skeleton) and found BMP production in most of these tumors. RESULTS: We found that BMPs were expressed in both bone-forming and non-bone-forming benign musculoskeletal lesions. In the first part of the study, BMPs were found in both fibrous dysplasia and desmoid tumors. Bone morphogenetic proteins were also expressed by several tumors. In the next part of the study (paraffin-embedded tissue), BMPs were expressed by a variety of tumors, irrespective of the radiological nature (blastic or lytic) of their metastases. CONCLUSIONS: We conclude that BMP production alone cannot explain bone formation, and other factors either alone or in combination may be responsible for blastic metastases to the skeleton and for bone formation by primary bone lesions, such as fibrous dysplasia.

Molecular targets in cancer therapy.

OBJECTIVES: To review selected pharmacologic agents that target key cellular processes along with their mechanisms of action and adverse events. Nursing implications including what patients and families need to know, administration issues, and management of common toxicities will be reviewed. DATA SOURCES: Research articles, clinical trials, abstracts, and book chapters. CONCLUSION: Knowledge of complex biology and biochemistry regulating normal and abnormal cellular function obtained over the past 30 years is starting to be used clinically for new therapies to treat cancer. By targeting what makes cancer unique, these therapies are able to spare more healthy or normal cells than the standard treatments, such as radiation and chemotherapy. Several molecular targeting agents are now in use and even more are under study as cancer treatments. IMPLICATIONS FOR NURSING PRACTICE: Oncology nurses must understand the principles underlying targeted treatments and their potential benefits to provide adequate patient education and care.

Expression of cytokines and receptors in normal, immortalized, and malignant ovarian epithelial cell lines.

BACKGROUND: Ovarian carcinoma originates from the epithelial cells on the surface of the ovary. This study evaluates cytokine production by these cells. MATERIALS AND METHODS: Normal human ovary surface epithelial cells (HOSE cells), immortalized HOSE cells and ovarian cancer cells were used for the study of cytokines. RESULTS: Eight of 14 cytokines were increased in > or = 3 ovarian cancer cell lines compared with normal HOSE cells. Three cytokines were increased 5-fold in the immortalized HOSE cell line and in multiple ovarian cancer cell lines. Cytokine receptor expression revealed that 7 of 8 ovarian cancer cell lines had > or = 1 autocrine loop. Anti-EGFR antibody failed to inhibit growth of ovarian cancer cells which expressed multiple cytokine receptors. CONCLUSION: Ovarian cancer cells produce more cytokines than normal HOSE cells. Immortalized HOSE cells display a cytokine profile similar to the cancer cells. Finally, multiple autocrine loops in ovarian cancer may limit the therapeutic usefulness of single cytokine receptor blockade.