Presence of interleukin 10 (IL-10) in the ascites of patients with ovarian and other intra-abdominal cancers

The complex role of IL-10 in malignant ascites: a review

The emergence of malignant ascites (MA) indicates poor prognoses in patients with ovarian, gastrointestinal, breast, and pancreatic cancer. Interleukin-10 (IL-10) is a pleiotropic cytokine with immunoregulatory effects in tumor microenvironment. The level of IL-10 in MA varied across cancer types and patients, influencing cancer progression and outcomes. Originating from various immune and cancer cells, IL-10 contributes to complex signaling pathways in MA. Systemic IL-10 administration, although the evidence of its efficacy on MA is limited, still emerges as a promising therapeutic strategy because it can increase CD8+ T cells cytotoxicity and invigorate exhausted CD8+ tumor infiltration lymphocytes (TILs) directly. IL-10 signaling blockade also demonstrates great potential when combined with other immunotherapies in MA treatment. We reviewed the levels, origins, and functions of IL-10 in malignant ascites and overviewed the current IL-10 signaling targeting therapies, aiming to provide insights for MA treatment.

Pigment epithelium-derived factor promotes peritoneal dissemination of ovarian cancer through induction of immunosuppressive macrophages

Peritoneal dissemination of ovarian cancer (OC) correlates with poor prognosis, but the mechanisms underlying the escape of OC cells from the intraperitoneal immune system have remained unknown. We here identify pigment epithelium–derived factor (PEDF) as a promoting factor of OC dissemination, which functions through induction of CD206⁺ Interleukin-10 (IL-10)–producing macrophages. High PEDF gene expression in tumors is associated with poor prognosis in OC patients. Concentrations of PEDF in ascites and serum are significantly higher in OC patients than those with more benign tumors and correlated with early recurrence of OC patients, suggesting that PEDF might serve as a prognostic biomarker. Bromodomain and extraterminal (BET) inhibitors reduce PEDF expression and limit both OC cell survival and CD206⁺ macrophage induction in the peritoneal cavity. Our results thus implicate PEDF as a driver of OC dissemination and identify a BET protein–PEDF–IL-10 axis as a promising therapeutic target for OC.

Endogenously expressed pigment epithelium–derived factor (PEDF) promotes increased survival of ovarian cancer cells in the peritoneal cavity by inducing IL-10 expression in CD206 ⁺ peritoneal macrophages.

Interleukin 10 level in the peritoneal cavity is a prognostic marker for peritoneal recurrence of T4 colorectal cancer

Peritoneal recurrence (PR) is a major relapse pattern of colorectal cancer (CRC). We investigated whether peritoneal immune cytokines can predict PR. Cytokine concentrations of peritoneal fluid from CRC patients were measured. Patients were grouped according to peritoneal cancer burden (PCB): no tumor cells (≤ pT3), microscopic tumor cells (pT4), or gross tumors (M1c). Cytokine concentrations were compared among the three groups and the associations of those in pT4 patients with and without postoperative PR were assessed. Of the ten cytokines assayed, IL6, IL10, and TGFB1 increased with progression of PCB. Among these, IL10 was a marker of PR in pT4 (N = 61) patients based on ROC curve (p = 0.004). The IL10 cut-off value (14 pg/mL) divided patients into groups with a low (7%, 2 of 29 patients) or high (45%, 16 of 32 patients) 5-year PR (p < 0.001). Multivariable analysis identified high IL10 levels as the independent risk factor for PR. Separation of patients into training and test sets to evaluate the performance of IL10 cut-off model validated this cytokine as a risk factor for PR. Peritoneal IL10 is a prognostic marker of PR in pT4 CRC. Further research is necessary to identify immune response of intraperitoneal CRC growth.

Specialized immune responses in the peritoneal cavity and omentum

The peritoneal cavity is a fluid filled space that holds most of the abdominal organs, including the omentum, a visceral adipose tissue that contains milky spots or clusters of leukocytes that are organized similar to those in conventional lymphoid tissues. A unique assortment of leukocytes patrol the peritoneal cavity and migrate in and out of the milky spots, where they encounter Ags or pathogens from the peritoneal fluid and respond accordingly. The principal role of leukocytes in the peritoneal cavity is to preserve tissue homeostasis and secure tissue repair. However, when peritoneal homeostasis is disturbed by inflammation, infection, obesity, or tumor metastasis, specialized fibroblastic stromal cells and mesothelial cells in the omentum regulate the recruitment of peritoneal leukocytes and steer their activation in unique ways. In this review, the types of cells that reside in the peritoneal cavity, the role of the omentum in their maintenance and activation, and how these processes function in response to pathogens and malignancy will be discussed.

Myeloid-Derived Suppressor Cells Promote Metastasis in Breast Cancer After the Stress of Operative Removal of the Primary Cancer

Objective: To investigate the role of myeloid-derived suppressor cells (MDSC) in cancer progression after the stress of operative removal and the potential treatment value of MDSC depletion. Summary Background Data: Surgery is the most important treatment strategy in breast cancer. Recent research has provided evidence that operations may promote cancer metastases under some circumstances. Methods: A mouse model of breast cancer (administration of the murine breast cancer 4T1 cells subcutaneously) and the stress of operation were used to compare immune responses and survival outcomes. Flow cytometry was performed to detect the expression of CD11b and Gr1 MDSCs in tumor tissues and lung metastases. Cytokine levels were detected with three-color flow cytometry and enzyme-linked immunosorbent assay (ELISA). MDSCs were isolated and co-cultured with 4T1 cells to identify any morphological change with immunofluorescence. The anti Gr-1 antibody was used to detect the function of the anti-Gr1 treatment in breast cancer. Results: The operative stress impaired the overall survival, leading to an increased number of MDSCs that preferentially infiltrated the tumor microenvironment and promoted tumor metastasis. In both in vitro and in vivo assays, MDSCs induced the epithelial-mesenchymal transition (EMT) of tumor cells through the up-regulation of TGF-beta1, VEGF, and IL-10. Furthermore, a treatment strategy of MDSC depletion was found to reduce pulmonary metastases after operations. Conclusions: The stress of operation could impair the overall survival in mice. The infiltrated MDSCs appear to induce EMT of tumor cells and increase metastases through the up-regulation of TGF-beta1, VEGF, and IL-10 levels. MDSC depletion could be a promising treatment strategy to prevent immune evasion after operations.

Epigenetic Crosstalk between the Tumor Microenvironment and Ovarian Cancer Cells: A Therapeutic Road Less Traveled

Metastatic dissemination of epithelial ovarian cancer (EOC) predominantly occurs through direct cell shedding from the primary tumor into the intra-abdominal cavity that is filled with malignant ascitic effusions. Facilitated by the fluid flow, cells distribute throughout the cavity, broadly seed and invade through peritoneal lining, and resume secondary tumor growth in abdominal and pelvic organs. At all steps of this unique metastatic process, cancer cells exist within a multidimensional tumor microenvironment consisting of intraperitoneally residing cancer-reprogramed fibroblasts, adipose, immune, mesenchymal stem, mesothelial, and vascular cells that exert miscellaneous bioactive molecules into malignant ascites and contribute to EOC progression and metastasis via distinct molecular mechanisms and epigenetic dysregulation. This review outlines basic epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNA regulators, and summarizes current knowledge on reciprocal interactions between each participant of the EOC cellular milieu and tumor cells in the context of aberrant epigenetic crosstalk. Promising research directions and potential therapeutic strategies that may encompass epigenetic tailoring as a component of complex EOC treatment are discussed.

Ascites IL-10 Promotes Ovarian Cancer Cell Migration

Ovarian cancer (OC) ascites is an inflammatory and immunosuppressive tumor environment characterized by the presence of various cytokines, chemokines and growth factors. The presence of high concentrations of these cytokines/chemokines in ascites is associated with a more aggressive tumor phenotype. IL-10 is an immunosuppressive cytokine for which high expression has been associated with poor prognosis in some cancers. However, its role on OC tumor cells has not been explored. Therefore, the aim of the current study was to elucidate the role of ascites IL-10 on the proliferation, migration and survival of OC cell lines. Here, we show that IL-10 levels are markedly increased in patients with advanced serous OC ascites relative to serous stage I/II ascites and peritoneal effusions from women with benign conditions. Ascites and IL-10 dose-dependently enhanced the proliferation and migration of OC cell lines CaOV3 and OVCAR3 but had no effect on cell survival. IL-10 levels in ascites positively correlated with the ability of ascites to promote cell migration but not proliferation. Depletion of IL-10 from ascites markedly inhibited ascites-induced OC cell migration but was not crucial for ascites-mediated cell proliferation. Taken together, our findings establish an important role for IL-10, as a component of ascites, in the migration of tumor cells.

Chromatin Binding of c-REL and p65 Is Not Limiting for Macrophage IL12B Transcription During Immediate Suppression by Ovarian Carcinoma Ascites

Tumors frequently exploit homeostatic mechanisms that suppress expression of IL-12, a central mediator of inflammatory and anti-tumor responses. The p40 subunit of the IL-12 heterodimer, encoded by IL12B, is limiting for these functions. Ovarian carcinoma patients frequently produce ascites which exerts immunosuppression by means of soluble factors. The NFκB pathway is necessary for transcription of IL12B, which is not expressed in macrophages freshly isolated from ascites. This raises the possibility that ascites prevents IL12B expression by perturbing NFκB binding to chromatin. Here, we show that ascites-mediated suppression of IL12B induction by LPS plus IFNγ in primary human macrophages is rapid, and that suppression can be reversible after ascites withdrawal. Nuclear translocation of the NFκB transcription factors c-REL and p65 was strongly reduced by ascites. Surprisingly, however, their binding to the IL12B locus and to CXCL10, a second NFκB target gene, was unaltered, and the induction of CXCL10 transcription was not suppressed by ascites. These findings indicate that, despite its reduced nuclear translocation, NFκB function is not generally impaired by ascites, suggesting that ascites-borne signals target additional pathways to suppress IL12B induction. Consistent with these data, IL-10, a clinically relevant constituent of ascites and negative regulator of NFκB translocation, only partially recapitulated IL12B suppression by ascites. Finally, restoration of a defective IL-12 response by appropriate culture conditions was observed only in macrophages from a subset of donors, which may have important implications for the understanding of patient-specific immune responses.

Positive feedback regulation between IL10 and EGFR promotes lung cancer formation

The role of IL10 in the tumorigenesis of various cancer types is still controversial. Here, we found that increased IL10 levels are correlated with a poor prognosis in lung cancer patients. Moreover, IL10 levels were significantly increased in the lungs and serum of EGFR^L858R- and Kras4b^G12D-induced lung cancer mice, indicating that IL10 might facilitate lung cancer tumorigenesis. IL10 knockout in EGFR^L858R and Kras4b^G12D mice inhibited the development of lung tumors and decreased the levels of infiltrating M₂ macrophages and tumor-promoting T_reg lymphocytes. We also showed that EGF increases IL10 expression by enhancing IL10 mRNA stability, and IL10 subsequently activates JAK1/STAT3, Src, PI3K/Akt, and Erk signaling pathways. Interestingly, the IL10-induced recruitment of phosphorylated Src was critical for inducing EGFR through the activation of the JAK1/STAT3 pathway, suggesting that Src and JAK1 positively regulate each other to enhance STAT3 activity. Doxycycline-induced EGFR^L858R mice treated with gefitinib and anti-IL10 antibodies exhibited poor tumor formation. In conclusion, IL10 and EGFR regulate each other through positive feedback, which leads to lung cancer formation.

Immunomodulatory Activity of VEGF in Cancer

The ability of tumor cells to escape tumor immunosurveillance contributes to cancer development. Factors produced in the tumor microenvironment create "tolerizing" conditions and thereby help the tumor to evade antitumoral immune responses. VEGF-A, already known for its major role in tumor vessel growth (neoangiogenesis), was recently identified as a key factor in tumor-induced immunosuppression. In particular, VEGF-A fosters the proliferation of immunosuppressive cells, limits T-cell recruitment into tumors, and promotes T-cell exhaustion. Antiangiogenic therapies have shown significant efficacy in patients with a variety of solid tumors, preventing tumor progression by limiting tumor-induced angiogenesis. VEGF-targeting therapies have also been shown to modulate the tumor-induced immunosuppressive microenvironment, enhancing Th1-type T-cell responses and increasing tumor infiltration by T cells. The immunomodulatory properties of VEGF-targeting therapies open up new perspectives for cancer treatment, especially through strategies combining antiangiogenic drugs with immunotherapy. Preclinical models and early clinical studies of these combined approaches have given promising results.

Antioxidant and immunity activities of Fufang Kushen Injection Liquid

We investigated the effects of Fufang Kushen Injection Liquid (FFKSIL) on gastric immunity and oxidant-antioxidant status during N-methyl-N′-nitro-N-nitroso-guanidine (MNNG)-induced gastric carcinogenesis. The extent of lipid peroxidation and the levels of reduced glutathione (GSH) and activities of the GSH-dependent enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were used to monitor the peroxidative balance. Enhanced lipid peroxidation in the gastric cancer animals was accompanied by significant decreases in the activities of GSH, GPx, GST and GR. Administration of FFKSIL significantly enhanced serum IgA, IgG, IgM, IL-2, IL-4 and IL-10 levels, decreased serum IL-6 and TNF-α levels, lowered the levels of lipid peroxides and enhanced GSH levels and activities of GSH-dependent enzymes. Our results suggest that FFKSIL blocks experimental gastric carcinogenesis by protecting against carcinogen-induced oxidative damage and improving immunity activity.

IL-10 immunomodulation of myeloid cells regulates a murine model of ovarian cancer

Elevated levels of IL-10 in the microenvironment of human ovarian cancer and murine models of ovarian cancer are well established and correlate with poor clinical prognosis. However, amongst a myriad of immunosuppressive factors, the actual contribution of IL-10 to the ovarian tumor microenvironment, the mechanisms by which it acts, and its possible functional redundancy are unknown. We previously demonstrated that elimination of the myeloid-derived suppressor cell (MDSC) compartment within the ovarian tumor ascites inhibited tumor progression and, intriguingly, significantly decreased local IL-10 levels. Here we identify a novel pathway in which the tumor-infiltrating MDSC are the predominant producers of IL-10 and, importantly, require it to develop their immunosuppressive function in vivo. Importantly, we demonstrate that the role of IL-10 is critical, and not redundant with other immunosuppressive molecules, to in vivo tumor progression: blockade of the IL-10 signaling network results in alleviation of MDSC-mediated immunosuppression, altered T cell phenotype and activity, and improved survival. These studies define IL-10 as a fundamental modulator of both MDSC and T cells within the ovarian tumor microenvironment. Importantly, IL-10 signaling is shown to be necessary to the development and maintenance of a permissive tumor microenvironment and represents a viable target for anti-tumor strategies.

Tumor-derived interleukin-10 as a prognostic factor in stage III patients undergoing adjuvant treatment with an autologous melanoma cell vaccine

OBJECTIVES

Interleukin-10 (IL-10) downregulates T-cell-mediated immune responses. We studied the association between IL-10 production by freshly isolated melanoma cell suspensions in vitro and overall survival in patients undergoing adjuvant treatment with a vaccine prepared from the same autologous melanoma cells modified with a hapten, dinitrophenyl (DNP).

METHODS

Forty-four patients with cutaneous melanoma (29 stage III and 15 stage IV) were prospectively evaluated. Tumor cells were extracted from metastatic deposits for production of DNP-modified autologous melanoma cell vaccine. Small aliquots of the melanoma cell suspensions were separated prior to vaccine processing and cultured overnight for IL-10 production. Based on a blind assessment of the distribution of IL-10 levels in the culture supernatants, a cutoff of 200 pg/ml was used to define high versus low IL-10 producers. Cox regression model was used for multivariate analysis. Overall survival was calculated using the Kaplan-Meier method, and survival curves were compared with the log-rank test.

RESULTS

Out of 44 patients, 29 were low and 15 were high IL-10 producers. The median OS was significantly worse for high compared with low IL-10 producers (10.5 months vs. 42 months; P = 0.022). In stage III patients, the multivariate hazard ratio for high versus low IL-10 producers was 2.92 (95% CI, 1.04-8.20; P = 0.041). The corresponding hazard ratio in stage IV patients was 0.92 (95% CI, 1.04-8.20; P = 0.888).

CONCLUSIONS

High IL-10 production in the tumor microenvironment could be a determinant of clinical outcomes in stage III melanoma patients receiving autologous melanoma cell vaccine.

How do tumors actively escape from host immunosurveillance?

The immunological background for the process of tumor growth is still obscure. However, our understanding of what happens could have important consequences, namely in the context of cancer immunotherapy. A tumor is able to grow in the host environment either because it is recognizable as normal tissue and tolerated by host immune cells, or because it can "escape" from host immunosurveillance. According to the second option the mechanisms of tumor recognition and consequent destruction are actively disturbed by such processes as: change of tumor immunogenicity, production of tumor-derived regulatory molecules, and interaction of cancer cells with tumor-infiltrating immune cells. The results of studies devoted to the problem of immunoregulation in the tumor environment seem to support the "escape" hypothesis.

Loss of tissue expression of interleukin-10 promotes the disease progression of colorectal carcinoma

PURPOSE

Interleukin-10 (IL-10) is a unique cytokine that is thought to be a potent immunostimulatory and immunosuppressive factor. The aim of this study was to investigate IL-10 expression in colorectal cancer, and clarify its relationship to the clinicopathological findings and prognosis.

METHODS

Tissue samples were collected from 92 patients with colorectal cancer and adjacent normal mucosa. The expression of IL-10 in colorectal cancer tissues was evaluated by immunohistochemistry. Tissue levels of IL-10 were measured by enzyme-linked immunosorbent assay.

RESULTS

The mean concentration of IL-10 did not significantly differ between the cancer tissue and adjacent normal mucosa. The IL-10 concentration in cancer tissue with positive staining immunohistochemically was significantly higher than that without IL-10 staining. The IL-10 level in cancer tissue decreased in accordance with advanced-stage serosal invasion and lymph node involvement, and thus predicted poor survival in patients undergoing surgery with curative intent. A Cox multivariate analysis demonstrated that a decreased IL-10 level in cancer tissue was an independent risk factor for poor survival.

CONCLUSION

The tumor IL-10 level in colorectal cancer was inversely correlated with serosal invasion and lymph node metastasis, which thus reflected tumor progression. Evaluating the tumor expression of IL-10 may therefore provide valuable information for predicting the long-term survival in patients undergoing surgery with curative intent.

Genomic and proteomic biomarkers for cancer: a multitude of opportunities

Biomarkers are molecular indicators of a biological status, and as biochemical species can be assayed to evaluate the presence of cancer and therapeutic interventions. Through a variety of mechanisms cancer cells provide the biomarker material for their own detection. Biomarkers may be detectable in the blood, other body fluids, or tissues. The expectation is that the level of an informative biomarker is related to the specific type of disease present in the body. Biomarkers have potential both as diagnostic indicators and monitors of the effectiveness of clinical interventions. Biomarkers are also able to stratify cancer patients to the most appropriate treatment. Effective biomarkers for the early detection of cancer should provide a patient with a better outcome which in turn will translate into more efficient delivery of healthcare. Technologies for the early detection of cancer have resulted in reductions in disease-associated mortalities from cancers that are otherwise deadly if allowed to progress. Such screening technologies have proven that early detection will decrease the morbidity and mortality from cancer. An emerging theme in biomarker research is the expectation that panels of biomarker analytes rather than single markers will be needed to have sufficient sensitivity and specificity for the presymptomatic detection of cancer. Biomarkers may provide prognostic information of disease enabling interventions using targeted therapeutic agents as well as course-corrections in cancer treatment. Novel genomic, proteomic and metabolomic technologies are being used to discover and validate tumor biomarkers individually and in panels.

Long-term interleukin-10 presence induces the development of a novel, monocyte-derived cell type

Interleukin (IL)-10 is one of the most crucial immunoregulatory cytokines. Its short-term effects have been analysed extensively, but little is known about its long-term effects. This is of considerable importance, as high systemic IL-10 levels are present for long periods in patients with persistent viral infections, certain cancers and in critical care patients. Our study investigated the effects of the long-term presence of IL-10 on human peripheral blood monocytes. In vitro, IL-10 treatment of these cells for 7 days induced the development of a novel cell type characterized by unique phenotypical and functional characteristics. These cells showed high HLA-DR expression and low expression of CD86 and other co-stimulatory molecules on their surface. The mRNA levels of both HLA-DR and CD86 were high, but no intracellular accumulation of CD86 protein was observed. With respect to its function, these cells showed strongly diminished tumour necrosis factor-alpha production following lipopolysaccharide stimulation, strongly diminished allogenic CD4(+) T cell stimulatory capacity, and even induced a hyporesponsive state in CD4(+) T cells. The phenotype remained stable despite the removal of IL-10. In vivo, we found monocytic cells from patients exhibiting this phenotype after long-term IL-10 exposure. These results complement our knowledge further about the biological effects of IL-10 and may provide an explanation for the sustained immunodeficiency in cases of the persistent presence of systemic IL-10.

Immunological profiling of a panel of human ovarian cancer cell lines

PURPOSE

The efficient identification of peptide antigens recognized by ovarian cancer-specific cytotoxic T lymphocytes (CTL) requires the use of well-characterized ovarian cancer cell lines. To develop such a panel of cell lines, 11 ovarian cancer cell lines were characterized for the expression of class I and class II major histocompatibility complex (MHC)-encoded molecules, 15 tumor antigens, and immunosuppressive cytokines [transforming growth factor beta (TGF-beta) and IL-10].

METHODS

Class I MHC gene expression was determined by polymerase chain reaction (PCR), and class I and class II MHC protein expression was determined by flow cytometry. Tumor antigen expression was determined by a combination of polymerase chain reaction (PCR) and flow cytometry. Cytokine expression was determined by ELISA.

RESULTS

Each of the ovarian cancer cell lines expresses cytokeratins, although each cell line does not express the same cytokeratins. One of the lines expresses CD90, which is associated with a fibroblast lineage. Each of the cell lines expresses low to moderate amounts of class I MHC molecules, and several of them express low to moderate amounts of class II MHC molecules. Using a combination of PCR and flow cytometry, it was determined that each cell line expressed between six and thirteen of fifteen antigens tested. Little to no TGF-beta3 was produced by any of the cell lines, TGF-beta1 was produced by three of the cell lines, TGF-beta2 was produced by all of the cell lines, with four of the cell lines producing large amounts of the latent form of the molecule, and IL-10 was produced by one of the cell lines.

CONCLUSIONS

Each of the 11 ovarian cancer lines is characterized by a unique expression pattern of epithelial/fibroblast markers, MHC molecules, tumor antigens, and immunosuppressive cytokines. Knowledge of these unique expression patterns will increase the usefulness of these cell lines in identifying the antigens recognized by ovarian cancer-specific CTL.

The expression of interleukin-10 in patients with primary ovarian epithelial carcinoma and in ovarian carcinoma cell lines

This study determined interleukin-10 (IL-10) expression in patients with ovarian carcinoma and in ovarian carcinoma cell lines, and investigated its clinical significance in the development and progression of ovarian carcinoma. Expression of IL-10 in ovarian carcinoma, benign ovarian tumour, normal control tissues and ovarian carcinoma cell lines was detected by immunohistochemistry and Western blot analysis. IL-10 concentrations in sera and ascites from patients with ovarian carcinoma, in sera from patients with benign ovarian tumour and normal controls, and in supernatants of ovarian carcinoma cell line cultures were measured by enzyme-linked immunosorbent assay. The tissue level of IL-10 in ovarian carcinoma was significantly higher than in benign ovarian tumour and normal controls. IL-10 expression was detectable in cell lysate and supernatant from ovarian carcinoma cell lines. In patients with ovarian carcinoma the IL-10 level in ascitic fluid was significantly higher than in sera, and the serum IL-10 level in ovarian carcinoma was significantly higher than in benign ovarian tumour and normal controls. Ascitic IL-10 levels in ovarian carcinoma were significantly correlated with disease stage but not cytological grade. These results suggest that ovarian carcinoma cells are able to synthesize and secrete IL-10, which probably assists in promoting the development and progression of ovarian carcinoma.

Epithelial ovarian cancer: disease etiology, treatment, detection, and investigational gene, metabolite, and protein biomarkers

Cancer research in recent years has immensely benefited from the development of novel technologies that enable scientists to perform detailed investigations of genomes, transcriptomes, proteomes, and metabolomes. This has invariably furthered knowledge of tumorigenesis and etiology of cancer. The resulting information can, in the foreseeable future, effect a significant change in the pace of cancer research, thereby producing improvements in patient care. Ovarian cancer in particular has received the interest of the scientific community, being the most frequent cause of death from gynecological cancers, characterized by few early symptoms, diagnosis at an advanced stage, as well as poor prognosis. Ovarian cancer is a malignancy in which normal ovarian cells begin to grow in an uncontrolled, abnormal manner and produce tumors in one or both ovaries. Epithelial cancers, the most common ovarian cancers (>80%), develop from cells lining the ovarian surface. Most ovarian cancer research is primarily focused on the early detection and treatment of epithelial ovarian cancer, the more common ovarian malignancy. This review offers an introduction to ovarian cancer, with particular emphasis on human epithelial ovarian cancer. Current methods of detection and therapy are discussed. A survey of promising new protein, gene, and metabolite biomarkers on the horizon is provided. Future prospects for improved diagnosis are offered.

Interleukin-10 in the pathophysiology of inflammatory bowel disease: increased serum concentrations during the recovery phase

Using a specific enzyme-linked immunosorbent assay, IL-10 concentrations were measured in serum from 62 patients with ulcerative colitis (UC), 43 with Crohn's disease (CD), 25 with other colitides, and 44 normal control subjects. Serum IL-10 concentrations were increased in patients with active UC but not in those with active CD when compared with normal control subjects. A time course study showed that in patients with UC and CD, serum concentrations of IL-6 and C-reactive protein increased during the acute phase and returned to normal as patients go into remission. Notably, serum IL-10 concentrations increased during the phase of disease resolution and declined thereafter regardless of the treatment modality. Gel filtration analysis indicated that IL-10 circulated predominantly as a dimer. In conclusion, this study shows that serum IL-10 is increased during disease recovery in patients with inflammatory bowel disease, and may be a helpful marker in monitoring disease status.

Paradoxical effects of cytokines in tumor immune surveillance and tumor immune escape

The role of cytokines in modulating the formation of new tumors is mediated by their ability to regulate antigen-specific anti-tumor responses and by the activation of non-specific mechanisms, including those involved in the processes of inflammation and innate resistance. Cytokines may influence the growth of tumors by acting directly on tumor cells as growth promoting or growth inhibiting factors or indirectly by attracting inflammatory cell types and affecting angiogenesis. Due to the potency and complexity of cytokine activity against tumor growth, the improvement of cloning techniques and the availability of recombinant forms of different cytokines, a great effort has been made in the recent years to exploit this anti-tumor potential for cancer therapy. This important goal has been difficult to achieve in most cases due to toxicity of most cytokines which could not be dissociated from their anti-tumoral functions. Nevertheless, if well designed, treatment protocols and/or modifications of the cytokine molecules may in some situations augment the anti-tumor effects while limiting the toxicity. One of these molecular approaches could be the design of peptides containing the functional domain of certain cytokines, exemplified by IT9302, a peptide homologous to the functional domain of IL-10, which has demonstrated to increase tumor NK cell sensitivity.

Epitomics: serum screening for the early detection of cancer on microarrays using complex panels of tumor antigens

Efforts toward the development of early detection assays for cancers have traditionally depended on single biomarker molecules. Current technologies have been disappointing and have not resulted in diagnostic tests suitable for clinical practice. Using a high-throughput cloning method, a panel of epitopes/antigens that react with autoantibodies to tumor proteins in the serum of patients with ovarian cancer have been isolated. Discovery of biomarker panels was directed in an unbiased fashion by cloning a large panel of epitopes or tumor antigens, rather than individual biomarkers without a previous notion of their function. The binding properties of these serum antitumor antibodies on microarrays and advanced bioinformatics tools led to a panel of diagnostic antigens. The sequences that were identified using this new technology will lead to the discovery of novel disease-related proteins that have diagnostic value for the presymptomatic detection of cancer. It has been demonstrated that this approach can detect these autoantibodies in the sera of Stage I ovarian cancer patients. There are numerous advantages of employing serum antibodies as the analytes, not the least of which is the ability to rapidly adapt these assays to standard clinical platforms. This technology of global epitope/antigen profiling is referred to as 'epitomics'.

Tissue homeostasis and cancer

Epithelial cells are known to release an important amount of cytokines capable to modulate immune system functions. On the other hand, immune system cells can release cytokines, which play an important role in the control of the growth of epithelial cells. In this paper, we stand the hypothesis that a mutual (reciprocal) growth regulation exists between epithelial cells and immune system. We propose a model describing plausible cytokine circuits that may regulate (inhibit) both epithelial growth and epithelial inflammation. In addition, we describe how dysfunction of these circuits could lead to tumoral growth, excessive inflammation or both. A failure in the regulation of epithelial growth by the immune system could give rise to a neoplasm, and a failure in the regulation of the immune system by the epithelium could give rise to inflammatory or autoimmune diseases. This model may satisfactorily explain the link between inflammation and cancer.

Improving antitumor immune responses by circumventing immunoregulatory cells and mechanisms

Although numerous immunotherapeutic strategies have been studied in patients with cancer, consistent induction of clinical responses remains a formidable challenge. Cancer vaccines are often successful at generating elevated numbers of tumor-specific T lymphocytes in peripheral blood, however, despite this, tumors usually continue to grow unabated. Recent evidence suggests that endogenous regulatory cells, known to play a major role in the induction of immune tolerance to self and prevention of autoimmunity, as well as suppressive myeloid cells invoked in the tumor-bearing state, may be largely responsible for preventing effective antitumor immune responses. This review will focus on the major regulatory cell subtypes, including CD4(+)CD25(+) T-regulatory cells, type 1 regulatory T cells, natural killer T cells, and immature myeloid cells. Studies in humans and in animal models have shown a role for all of these cells in tumor progression, although the mechanisms by which they act to suppress immunity remain largely undefined. Elucidation of the dominant molecular mechanisms mediating immune suppression in vivo will allow more precise targeting of the relevant regulatory cell populations, as well as the development of novel strategies and clinical reagents that will directly block molecules that induce the suppression of antitumor immunity.

Endometriosis as a model for inflammation–hormone interactions in ovarian and breast cancers

Chronic inflammation has been implicated in a variety of cancers. In this review, we consider associations between endometriosis and cancers both local (ovarian) and distant (breast). We review the epidemiological data linking endometriosis to ovarian and breast cancers. We then consider evidence for a role for sex steroid hormones and for inflammation in the aetiology of each of these cancers. Finally, we consider that endometriosis may promote alterations in sex steroid hormones and inflammatory mediators. A possible explanation for the association between endometriosis and these reproductive cancers may then be local and systemic enhancement of aberrant inflammatory and hormonal mediators. If this hypothesis is true, endometriosis may need to be considered as a risk factor for ovarian and breast cancers, triggering increasingly intensive surveillance. Moreover, treatments for endometriosis may require consideration of the impact on long-term cancer risk.

Preferential production of prostaglandin D2 by lipopolysaccharide stimulated human choriodecidual explants

It has been postulated that the progression of a pregnancy to term is, in part, the result of a relative maternal Th2 immunological state. Prostaglandins (PG) are critical mediators throughout pregnancy. Recent studies have demonstrated that one PG, PGD2, may be a mediator of a Th2 immunological state. To date, very little is known about the factors that regulate of PGD2 production by human gestational tissues. Placentae were collected from women undergoing Caesarean sections at term. Amnion was separated from the choriodecidua and choriodecidual explants established. Explants were allowed to equilibrate overnight in media containing 10% fetal calf serum. The following day, media were replaced with serum free media and then after an additional 24-h, media were collected and the wet weight of the tissues determined. Production rates of PGs were determined using radioimmunoassays. At all concentrations tested, LPS significantly enhanced PGD2 production by human choriodecidual explants compared to PGE2 and PGF2alpha production. Neutralization of TNF-alpha and IL-10 further increased the production of LPS stimulated PGD2 production. We suggest that a novel stimulatory pathway that drives the production of PGD2 has been uncovered.

The involvement of genetic polymorphism of IL-10 promoter in non-small cell lung cancer

STUDY OBJECTIVES

Interleukin-10 (IL-10) is mainly an anti-inflammatory cytokine produced by a number of cells including normal and neoplastic cells and has been implicated in autoimmunity, transplantation tolerance and tumorigenesis. Inter-individual variations in IL-10 production were genetically contributed to polymorphisms within IL-10 promoter region. The aim of this study was to determine whether polymorphisms in the IL-10 gene promoter were involved in predisposing an individual to non-small cell lung cancer (NSCLC).

PATIENTS

A total of 154 patients with non-small cell lung cancer were recruited into this study, together with 205 age- and gender-matched healthy smokers acting as control subjects.

MEASUREMENTS

Polymorphisms of sites within the promoter region of IL-10 gene were analyzed using polymerase chain reaction-restriction fragment length polymorphism technique on genomic DNA isolated from peripheral lymphocytes. The validity of this technique was proven by direct sequencing of polymerase chain reaction products. Statistical analyses were conducted to explore the contribution of polymorphism of IL-10 promoter to the susceptibility to NSCLC.

RESULTS

The distribution frequencies of genotypes of IL-10-1082, -819 and -592 were significantly different between NSCLC patients and controls. Pearson chi2 analysis showed that the frequency for IL-10-1082 G allele, IL-10-819C allele and IL-10-592C allele was independently higher in NSCLC patient group than that in the control group. Higher odds ratios (ORs) for NSCLC were seen for individuals with G allele of IL-10-1082 [OR=5.26, 95% CI 2.65-10.4, p<0.0001], C allele of IL-10-819 [OR=1.57, 95% CI 1.15-2.16, p=0.005], C allele of IL-10-592 [OR=1.59, 95% CI 1.15-2.19, p=0.005].

CONCLUSION

The polymorphisms of IL-10 genes were significantly associated with the occurrence of NSCLC.

Characterization of effusion-infiltrating T cells: benign versus malignant effusions

PURPOSE

While naïve T cells circulate between peripheral blood and lymph nodes, memory effector T cells acquire certain surface molecules that enable them to travel to peripheral tissues and exert their effector function. We analyzed whether deficient numbers of effector-type T cells within the malignant effusion might contribute to tumor escape from immunosurveillance.

EXPERIMENTAL DESIGN

We analyzed the expression of a broad range of adhesion molecules and chemokine receptors (CD62L, CD56, CCR4, CCR5, CCR7, CXCR3, CLA, and integrin alpha 4 beta 7) on tumor-associated lymphocytes in effusions and peripheral blood lymphocytes of patients with malignant ascites (n = 11) or malignant pleural effusion (n = 16). A tumor-associated lymphocyte:peripheral blood lymphocyte ratio was calculated as an indicator for homing of lymphocytes into the effusions and was compared with patients with nonmalignant ascites (n = 17).

RESULTS

Patients with malignancies show an increased enrichment of T cells expressing the phenotype of "naïve" (CD62L+ and CD45RA+CCR7+), "central memory" (CD45RA-CCR7+), and type 2-polarized (CCR4+) T cells within their effusions. In contrast, enrichment of "effector"-type (CD45RA-CCR7- or CD45RA+CCR7-) and presumably type 1-polarized T cells (CCR5+) at the tumor site is deficient. The same is true for natural killer cells and potentially cytotoxic CD56+ T cells.

CONCLUSIONS

Here we show for the first time that patients with malignant effusions show a deficient enrichment of T cells expressing the phenotype of type-1-polarized effector T cells at the tumor site. This mechanism is likely to contribute to the escape of tumor cells from immunosurveillance.

Persistent transgene expression following intravenous administration of a liposomal complex: role of interleukin-10-mediated immune suppression

Studies conducted in non-tumor-bearing, immunocompetent mice have shown that intravenous administration of liposome-DNA complex elicits an inflammatory response that results in a failure to sustain adequate transgene expression. In the present study, however, we investigated the effects of a cationic liposomal DOTAP:cholesterol (DOTAP:Chol)-DNA complex on cytokine production and transgene expression in both experimental lung tumor-bearing (TB) mice and non-tumor-bearing (NTB) syngeneic mice and nude mice. Intravenous injection of DOTAP:Chol-luciferase (luc) DNA complex resulted in tumor necrosis factor-alpha levels that were 50% lower and interleukin-10 levels that were 50-60% higher in TB mice than in NTB mice. Furthermore, a significant increase in luc expression (P = 0.001) that persisted for 7 days was observed in TB mice. In contrast, luc expression decreased significantly from day 1 to day 2 in NTB mice. Also, luc expression was two- to threefold higher in TB mice that were given multiple injections of DOTAP:Chol-luc complex than in mice who received a single injection. In contrast, luc expression was significantly suppressed following multiple injections in NTB mice (P = 0.01). Further analysis revealed IL-10 protein expression by the tumor cells in TB mice. Injection of anti-IL-10 antibody in TB mice resulted in a significant decrease in luc expression (P = 0.01) compared with that in mice injected with a control antibody. Based on these findings, we conclude that transgene expression persists in TB mice and is partly mediated by IL-10. Additionally, multiple injections of liposome-DNA complex can increase transgene expression in TB mice. These findings have clinical applications in the treatment of cancer.

A Synthetic Peptide Homologous to Functional Domain of Human IL-10 Down-Regulates Expression of MHC Class I and Transporter Associated with Antigen Processing 1/2 in Human Melanoma Cells

Tumor cells treated with IL-10 were shown to have decreased, but peptide-inducible expression of MHC class I, decreased sensitivity to MHC class I-restricted CTL, and increased NK sensitivity. These findings could be explained, at least partially, by a down-regulation of TAP1/TAP2 expression. In this study, IT9302, a nanomeric peptide (AYMTMKIRN), homologous to the C-terminal of the human IL-10 sequence, was demonstrated to mimic these previously described IL-10 effects on MHC class I-related molecules and functions. We observed a dose-dependent down-regulation of MHC class I at the cell surface of melanoma cells after 24-h treatment with IT9302. The IL-10 homologue peptide also caused a dose-dependent inhibition of the IFN-gamma-mediated surface induction of MHC class I in a melanoma cell line. We demonstrated, using Western blot and flow cytometry, that IT9302 inhibits the expression of TAP1 and TAP2 proteins, but not MHC class I H chain or low molecular protein molecules. Finally, peptide-treated melanoma cells were shown to be more sensitive to lysis by NK cells in a dose-dependent way. Taken together, these results demonstrate that a small synthetic peptide derived from IL-10 can mimic the Ag presentation-related effects mediated by this cytokine in human melanomas and increase tumor sensitivity to NK cells, which can be relevant in the designing of future strategies for cancer immune therapy.

Restoration of tumor specific human leukocyte antigens class I-restricted cytotoxicity by dendritic cell stimulation of tumor infiltrating lymphocytes in patients with advanced ovarian cancer

Despite the large number of potentially cytotoxic tumor-infiltrating (TIL) and tumor-associated (TAL) lymphocytes accumulated in the peritoneal cavity ascitic fluid and tumor tissue, advanced ovarian cancer is a progressive disease, suggesting that TIL and TAL populations eventually become functionally suppressed in vivo. Dendritic cells (DC) are the most powerful professional antigen presenting cells known in humans and recently, ovarian tumor antigen pulsed DC have been shown to elicit tumor specific human leukocyte antigens (HLA)-class I-restricted cytotoxicity from the peripheral blood of advanced ovarian cancer patients. In this study, we have evaluated the potential of tumor antigen-pulsed fully mature DC stimulation in restoring tumor-specific cytotoxicity in anergic TIL populations from advanced ovarian cancer patients. In addition, we have compared tumor-specific T-cell responses induced by tumor antigen-loaded DC in TIL to those induced in TAL and peripheral blood lymphocytes (PBL). DC stimulation induced powerful cytotoxicity against autologous tumor target cells in TIL-derived CD8+ T-cells from all patients tested, while autologous Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL) were not lysed. Killing of autologous tumor cells was higher by CD8+ T-cells from TIL compared to PBL and TAL (P < 0.01) and was more strongly inhibited by anti-HLA class I MAb (P < 0.05 compared to PBL and TAL). Phenotypically, all cytotoxic T lymphocyte (CTL) populations were CD3+/CD8+, with variable levels of CD56 expression. Finally, although a marked Type 1 cytokine bias [ie, interferon-gamma/interleukin-4 (IFN-gammahigh/IL-4low)] was observable in all DC-stimulated CD8+ T-cell populations, TIL derived CD8+ T-cells showed a higher percentage of IFN-gamma positive cells compared to TAL and PBL. Taken together, these data show that tumor lysate-pulsed DC can consistently restore strong CD8+ CTL responses from TIL against autologous ovarian cancer cells. DC-stimulated TIL may represent a superior source of tumor-specific CTL for adoptive T-cell immunotherapy for advanced ovarian cancer.

Phenotype and antitumor activity of ascitic fluid monocytes in patients with ovarian carcinoma

Monocytes/macrophages (MO/MA) represent a major leukocyte population in the peritoneal cavity of patients with epithelial ovarian cancer (EOC). We examined the phenotypic characteristics and antitumor cell activity of ascitic MO in patients with EOC. MO/MA phenotype was compared with MO in peripheral blood by two- and three-color flow cytometry. Cytotoxic/cytostatic effects of different cytokines on cultured EOC cells were measured by initial labeling or uptake inhibition of [methyl-3H] thymidine. Malignant ascites had higher proportion of MO/MA with the CD14brightCD16+ phenotype than peripheral blood. Cell surface antigen expression of activation and differentiation in peripheral blood and ascites, including CD38, CD40, CD64, and CD86, was higher on CD14brightCD16- and CD14brightCD16+ than on CD14dimCD16- cells. HLA-DR expression was higher on ascitic MO/MA than peripheral blood MO. Significant cytotoxic/cytostatic activity was elicited by treating ascitic MO/MA with interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), but not with interleukin-12, paclitaxel, granulocyte-monocyte colony-stimulating factor (GM-CSF), or tumor necrosis factor-alpha (TNF-alpha). Soluble CD40Lt did not enhance MO/MA cytotoxic activity, and inhibited IFN-gamma or IL-2 induced cytoxicity. We conclude that MO/MA from ascites have elevated proportions of CD14brightCD16+ cells, showing phenotypic features of activation. IFN-gamma induces the cytotoxic and cytostatic activity of MO/MA that is inhibited by CD40Lt.

Critical paracrine interactions between TNF-alpha and IL-10 regulate lipopolysaccharide-stimulated human choriodecidual cytokine and prostaglandin E2 production

Increased production of PGs by gestational membranes is believed to be a principal initiator of term and preterm labor. Intrauterine infection is associated with an inflammatory response in the choriodecidua characterized by elevated production of cytokines and PGs. The precise physiological significance of enhanced choriodecidual cytokine production in the mechanism of preterm labor remains uncertain. These studies were undertaken to dissect the roles and regulation of endogenous cytokines in regulating PG production by human choriodecidua. We used LPS treatment of human choriodecidual explants as our model system. In choriodecidual explant cultures, LPS (5 microg/ml) induced a rapid increase in TNF-alpha production, peaking at 4 h. In contrast, IL-10, IL-1beta, and PGE2 production rates peaked 8, 12, and 24 h, respectively, after LPS stimulation. Immunoneutralization studies indicated that TNF-alpha was a primary regulator of IL-1beta, IL-10, and PGE2 production, while IL-1beta stimulated only PGE2 production. Neutralization of endogenous IL-10 resulted in increased TNF-alpha and PGE2 production. IL-10 treatment markedly decreased TNF-alpha and IL-1beta production, but had no effect on PGE2 production. Taken together, these results demonstrate that the effects of LPS on choriodecidual cytokine and PG production are modulated by both positive and negative feedback loops. In the setting of an infection of the intrauterine, TNF-alpha may be a potential target for treatment intervention; IL-10 could be one such therapeutic.

Potent immunosuppressive activities of cytomegalovirus-encoded interleukin-10

Cytomegalovirus (CMV) has highly evolved mechanisms for avoiding detection by the host immune system. Recently, in the genomes of human and primate CMV, a novel gene comprising segments of noncontiguous open reading frames was identified and found to have limited predicted homology to endogenous cellular interleukin-10 (IL-10). Here we investigate the biological activities of the CMV IL-10-like gene product and show it to possess potent immunosuppressive properties. Both purified bacterium-derived recombinant CMV IL-10 and CMV IL-10 expressed in supernatants of human cells were found to inhibit proliferation of mitogen-stimulated peripheral blood mononuclear cells (PBMCs), with specific activity comparable to that of recombinant human IL-10. In addition, CMV IL-10 expressed from human cells inhibited cytokine synthesis, as treatment of stimulated PBMCs and monocytes with CMV IL-10 led to a marked decrease in production of proinflammatory cytokines. Finally, CMV IL-10 was observed to decrease cell surface expression of both major histocompatibility complex (MHC) class I and class II molecules, while conversely increasing expression of the nonclassical MHC allele HLA-G. These results demonstrate for the first time that CMV has a biologically active IL-10 homolog that may contribute to immune evasion during virus infection.

Immunology of the peritoneal cavity: relevance for host-tumor relation

The peritoneal membrane, formed by a single layer of mesothelial cells, lines the largest cavity of the human body. Anatomic structures of the peritoneal cavity, along with resident leukocyte populations, play an important role in the defense against microorganisms invading by breaching the gut integrity or ascending through the female genital tract. Local immune mechanisms in the peritoneal cavity are also important in patients undergoing peritoneal dialysis and in women with endometriosis. There is now extensive evidence demonstrating the significance of peritoneal immune mechanisms in the control of metastatic spread. Leukocytes belonging to both the innate and adaptive immune systems are present in the peritoneal cavity of normal subjects as well as in patients with intra-abdominal cancer. There is now increased understanding of the mechanisms that not only allow the tumor cells to escape the detection and destruction by the host immune system, but also to use the inflammatory mechanisms to promote tumor growth and spread inside the peritoneal cavity. Malignant ascites represents a model for the study of the interaction between tumor cells and the host immune system as well for the analysis of the tumor microenviroment. The peritoneal immune system may be stimulated by intraperitoneal administration of biologic agents. This peritoneal immunotherapy may be used for palliation of malignant ascites, or as a consolidation strategy in patients with minimal residual disease.

Interleukin-10 and the interleukin-10 receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Increased levels of interleukin-10 and transforming growth factor-beta in the plasma and ascitic fluid of patients with advanced ovarian cancer

OBJECTIVES

To assess expression of the immunosuppressive cytokines IL-10 and TGF-beta in the ascitic fluid and plasma of advanced ovarian cancer patients.

DESIGN

A prospective study.

SETTING

The Department of Obstetrics and Gynaecology at the University of Arkansas for Medical Sciences.

POPULATION

Twenty-eight women diagnosed with advanced ovarian cancer and ten normal female controls.

METHODS

Plasma and ascitic samples were collected at the time of surgery and analysed for the presence of IL-10 and TGF-beta using a sensitive enzyme-linked immunosorbent assay.

RESULTS

Elevated levels of IL-10 were detected in the plasma [mean (SD) = 12 (5) pg/mL; range 8 to 23 pg/mL] and in the peritoneal fluid [mean (SD) = 165 (137) pg/mL; range 50 to 556 pg/mL] of ovarian cancer patients, while no detectable IL-10 was found in any of the normal control plasma samples tested. Similarly, plasma levels of TGF-beta in ovarian cancer patients were significantly higher [mean (SD) = 1,506 (246) pg/mL; range 1,020 to 2,070 pg/mL] compared with controls [mean (SD) = 937 (187) pg/mL; range 770 to 1,140 pg/mL](P < 0.001). Surprisingly, however, although elevated TGF-beta levels were also detected in the peritoneal fluid of all ovarian cancer patients [mean (SD) = 407 (158) pg/mL; range 140 to 770 pg/mL], these levels were significantly lower than those seen in matched plasma samples (P < 0.001).

CONCLUSIONS

Local and systemic secretion of immunosuppressive cytokines may play an important role in the impaired anti-tumour immune function commonly observed in advanced ovarian cancer. However, the observation that plasma levels of TGF-beta are significantly higher than those detected in the ascitic fluid raises the possibility that cells other than tumour cells are responsible for TGF-beta release in the bloodstream of these patients.

Evaluation of recombinant human interleukin-12 in patients with recurrent or refractory ovarian cancer: a gynecologic oncology group study

Objective. The goal of this study was to estimate the antitumor activity and toxicity of recombinant human interleukin-12 (rhIL-12) in patients with recurrent or refractory epithelial ovarian cancer. Methods. From December 1997 to March 1999, patients with recurrent or refractory epithelial ovarian cancer were entered on a Gynecologic Oncology Group phase II study of intravenous rhIL-12. All patients had measurable disease, had a performance status of 0-2, and had failed first-line platinum-based chemotherapy regimen. Eligible patients received rhIL-12, 250 ng/kg IV bolus, as a single dose on Day 1 followed by a 2-week rest period, with subsequent cycles administered daily for 5 days followed by a 16-day rest period per cycle, until disease progression or adverse effects prohibited further therapy. Results. Twenty-eight patients were entered and evaluable for toxicity, while 26 were evaluable for response. The median age was 59.5 years (range: 45-77). The median number of cycles was 2 (range: 1-9). There were no complete responders; however, one patient (3.8%) was a partial responder and 13 patients (50%) had stable disease. Grade 4 myelotoxicity occurred in 21% of patients. Two patients experienced capillary leak syndrome: one grade 2 and one grade 4. Conclusion. As a single agent, rhIL-12 is tolerable and shows a low response rate in recurrent epithelial cancer with measurable disease.

Comparison of serum interleukin-10 (IL-10) levels between normal volunteers and patients with advanced melanoma

Melanoma is an immunoresponsive malignancy. Interleukin-10 (IL-10) is a potent regulator of immunosuppression. The purpose of this research was to define the relationship of serum IL-10 to survival in patients with metastatic melanoma. Forty-one melanoma patients and 50 normal volunteers were analyzed. The median IL-10 level as determined by enzyme-linked immunosorbent assay (ELISA) in melanoma patients was 8.75 pg/ml compared to < 3.0 pg/ml in normal volunteers (p = 0.0001). Survival of melanoma patients with an IL-10 level above 10.0 pg/ml was 365 days compared to 557 days in patients with IL-10 levels less than 10.0 pg/ml (p = 0.0259, Wilcoxon). Elevated IL-10 levels were correlated with poor survival.

Interleukin-10 and the Interleukin-10 Receptor

Interleukin-10 (IL-10), first recognized for its ability to inhibit activation and effector function of T cells, monocytes, and macrophages, is a multifunctional cytokine with diverse effects on most hemopoietic cell types. The principal routine function of IL-10 appears to be to limit and ultimately terminate inflammatory responses. In addition to these activities, IL-10 regulates growth and/or differentiation of B cells, NK cells, cytotoxic and helper T cells, mast cells, granulocytes, dendritic cells, keratinocytes, and endothelial cells. IL-10 plays a key role in differentiation and function of a newly appreciated type of T cell, the T regulatory cell, which may figure prominently in control of immune responses and tolerance in vivo. Uniquely among hemopoietic cytokines, IL-10 has closely related homologs in several virus genomes, which testify to its crucial role in regulating immune and inflammatory responses. This review highlights findings that have advanced our understanding of IL-10 and its receptor, as well as its in vivo function in health and disease.

Analysis of type T1 and T2 cytokines in patients with prostate cancer

BACKGROUND

It has been proposed that a dysregulation in the balance between type T1 (IL-2, IFN-gamma) and type T2 (IL-4, IL-10) cytokines may be implicated in the development of cancer.

METHODS

We determined the expression of IL-2, IL-4, IL-10, and IFN-gamma in CD4 and CD8 lymphocytes by flow cytometry in 12 patients with prostate cancer and in 7 healthy subjects. In addition to the basal expression of these cytokines, their expression was also determined, following stimulation of lymphocytes with PMA (phorbol 12-mystirate 13 acetate) and ionomycin.

RESULTS

The basal expression of cytokines was scarce, while following stimulation this increased markedly. On the other hand, there was a dysregulation in the balance between T1 and T2 lymphocytes in patients with prostate cancer. To this effect, in relation to healthy subjects, we observed an increase in IL-10 expression and a decrease in IL-2 expression.

CONCLUSIONS

The disequilibrium observed in the balance between type T1 and type T2 cytokines may be implicated in the evolution of neoplastic disease.

Serum interleukin-10 levels as a prognostic factor in advanced non-small cell lung cancer patients

STUDY OBJECTIVE

To investigate the prognostic significance of interleukin (IL)-10 serum levels in advanced non-small cell lung cancer (NSCLC) patients.

DESIGN

IL-10 serum levels were measured before chemotherapy, on completion of therapy, and at follow-up by means of a commercially available enzyme-linked immunoassay. The results were then analyzed in comparison with other prognostic variables, and a model predicting overall survival (OS) and time to treatment failure (TTF) was finally generated.

SETTING

University hospital.

PATIENTS

Sixty consecutive patients with TNM stage III or IV NSCLC undergoing conventional platinum-based regimens.

RESULTS

Elevated levels of serum IL-10 were found in cancer patients with respect to healthy control subjects (17.7 +/- 4.4 vs 9.2 +/- 1.5 pg/mL, respectively; p < 0.05), with patients with metastatic disease showing significantly higher levels than patients with undisseminated cancer (21.0 +/- 4.2 vs 14.3 +/- 1.2 pg/mL, respectively; p < 0.05). Following completion of treatment, patients were classified as responders if they had achieved either one of the following: complete response, partial response, or stable disease; and nonresponders, in case of progressive disease. Retrospective analysis of basal IL-10 serum levels in these two subgroups showed a significant difference between responders and nonresponders (15.2 +/- 2.2 vs 21.4 +/- 4.2 pg/mL, respectively; p < 0.05). Moreover, a further significant increase in IL-10 serum levels was observed in nonresponders at the end of therapy (21.4 +/- 4.2 vs 26.0 +/- 4.3 pg/mL, prechemotherapy and postchemotherapy, respectively; p < 0.05), whereas values in responders were found to have significantly decreased (15.2 +/- 2.2 vs 14.8 +/- 2.2 pg/mL, prechemotherapy and postchemotherapy, respectively; p < 0.05). Using univariate and multivariate analyses, both OS and TTF were shown to be affected by the mean pathologic levels of IL-10. Stepwise regression analysis identified IL-10 serum level and stage as the prognostic factors related to OS, and IL-10 serum level and performance status as the prognostic factors related to TTF.

CONCLUSIONS

In conclusion, this study shows that the measurement of pretreatment IL-10 serum levels is of independent prognostic utility in patients with NSCLC and may be useful for detection of disease progression.

IL-2 Plasmid Therapy of Murine Ovarian Carcinoma Inhibits the Growth of Tumor Ascites and Alters Its Cytokine Profile

We have evaluated whether i.p. murine ovarian tumors could be treated with an IL-2 plasmid DNA complexed with the cationic lipid, (±)-N-(2-hydroxyethyl)-N,N-dimethyl-2,3-bis(tetradecyloxy)-1-propanaminium bromide/dioleoylphosphatidylethanolamine (DMRIE/DOPE). Reporter gene studies were initially conducted in which mice bearing i.p. murine ovarian teratocarcinoma (MOT) were injected i.p. with reporter gene plasmid DNA (pDNA):DMRIE/DOPE. Histochemical analyses revealed that transfection occurred primarily in the tumor cells of the ascites, with only a minority of other ascitic cells or surrounding tissues transfected. IL-2 levels in the MOT ascites were determined after i.p. injection of either IL-2 pDNA:DMRIE/DOPE or recombinant IL-2 protein. IL-2 was detected in tumor ascites for up to 10 days after a single i.p. injection of IL-2 pDNA:DMRIE/DOPE, but was undetectable 24 h after a single i.p. injection of IL-2 protein. In an antitumor efficacy study, MOT tumor-bearing mice injected i.p. with IL-2 pDNA:DMRIE/DOPE on days 5, 8, and 11 after tumor cell implant had a significant inhibition of tumor ascites (p = 0.001) as well as a significant increase in survival (p = 0.008). A cytokine profile of the MOT tumor ascites revealed that mice treated with IL-2 pDNA:DMRIE/DOPE had an IL-2-specific increase in the levels of IFN-γ and GM-CSF. Taken together, these findings indicate that i.p. treatment of ovarian tumors with IL-2 pDNA:DMRIE/DOPE can lead to an increase in local IL-2 levels, a change in the cytokine profile of the tumor ascites, and a significant antitumor effect.