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Ena Wang

Publications and source records attributed to Ena Wang.

At least 37 records · Page 2Linked to original sources
PubMed2005

Polarized monocyte response to cytokine stimulation.

BACKGROUND: Mononuclear phagocytes (MPs) stand at the crossroads between the induction of acute inflammation to recruit and activate immune effector cells and the downmodulation of the inflammatory process to contain collateral damage. This decision is extensively modulated by the cytokine microenvironment, which includes a broad array of cytokines whose direct effect on MPs remains largely unexplored. Therefore, we tested whether polarized responses of MPs to pathogens are related to the influence of selected cytokines or represent a mandatory molecular switch through which most cytokines operate. RESULTS: Circulating CD14+ MPs were exposed to bacterial lipopolysaccharide (LPS) followed by exposure to an array of cytokines, chemokines and soluble factors involved in the immune response. Gene expression was studied by global transcript analysis. Two main classes of cytokines were identified that induced a classical or an alternative pathway of MP activation. Expression of genes affected by NFkappaB activation was most predictive of the two main classes, suggesting that this pathway is a fundamental target of cytokine regulation. As LPS itself induces a classical type of activation, the most dramatic modulation was observed toward the alternative pathway, suggesting that a broad array of cytokines may counteract the pro-inflammatory effects of bacterial components. CONCLUSIONS: This analysis is directly informative of the primary effect of individual cytokines on the early stages of LPS stimulation and, therefore, may be most informative of the way MP maturation may be polarized at the early stages of the immune response.

Adult↗
PubMed2005

Peritoneal and subperitoneal stroma may facilitate regional spread of ovarian cancer.

PURPOSE: Epithelial ovarian cancer (EOC) is characterized by early peritoneal involvement ultimately contributing to morbidity and mortality. To study the role of the peritoneum in fostering tumor invasion, we analyzed differences between the transcriptional repertoires of peritoneal tissue lacking detectable cancer in patients with EOC versus benign gynecologic disease. EXPERIMENTAL DESIGN: Specimens were collected at laparotomy from patients with benign disease (b) or malignant (m) ovarian pathology and comprised primary ovarian tumors, paired bilateral specimens from adjacent peritoneum and attached stroma (PE), subjacent stroma (ST), peritoneal washes, ascites, and peripheral blood mononuclear cells. Specimens were immediately frozen. RNA was amplified by in vitro transcription and cohybridized with reference RNA to a custom-made 17.5k cDNA microarray. RESULTS: Principal component analysis and unsupervised clustering did not segregate specimens from patients with benign or malignant pathology. Class comparison identified differences between benign and malignant PE and ST specimens deemed significant by permutation test (P = 0.027 and 0.012, respectively). A two-tailed Student's t test identified 402 (bPE versus mPE) and 663 (mST versus bST) genes differentially expressed at a significance level of P2 < or = 0.005 when all available paired samples from each patient were analyzed. The same comparison using one sample per patient reduced the pool of differentially expressed genes but retained permutation test significance for bST versus mST (P = 0.031) and borderline significance for bPE versus mPE (P = 0.056) differences. CONCLUSIONS: The presence of EOC may foster peritoneal implantation and growth of cancer cells by inducing factors that may represent molecular targets for disease control.

Computational Biology↗
PubMed2005

Gene profiling of immune responses against tumors.

Clinical trials of tumor-antigen-specific immunization have clearly shown that immune-mediated tumor rejection requires more than simple T cell-target cell interactions. In vivo generation of tumor-specific T cells is one of a series of steps necessary for the induction of clinically relevant immune responses. In recent years, high-throughput functional genomics exposed the complexity of tumor immune biology, which underlies the kaleidoscopic array of variables associated with cancer instability and immunogenetic variability in humans. In the quest to understand immune rejection, hypothesis-driven approaches have failed to take into account the intricacy of human pathology by relying mostly on hypotheses derived from experimental models rather than direct clinical observation. Future investigations should reframe scientific thinking when applied to humans, utilizing descriptive tools to generate novel hypotheses relevant to human disease.

Gene Expression Profiling↗
PubMed2005

Infectious pathogen detection arrays: viral detection in cell lines and postmortem brain tissue.

A unique array-based pathogen chip has been developed for the detection of viral RNA or DNA relevant to pathologies of the central nervous system. A total of 715 unique oligonucleotides (60-mer) representing approximately 100 pathogens were designed based on open reading frames (ORFs) from highly conserved and heterogenic regions within viral families. In addition, viral genes reflecting different stages of pathogen infection were also included to potentially define the stage of the viral infection. Viruses (double-stranded DNA, double- or single-stranded RNA, delta, retroid), parasites, and bacteria were included. Test samples labeled with Cy5 were examined by cohybridization with a reference RNA, labeled with Cy3, to the pathogen microarray chip. Good reproducibility of experiments was observed, based on data generated from duplicate hybridizations and duplicate spots on the microarray platform. A viral transcript detection sensitivity of 1 x 10(3) plaque-forming units (pfus) was achieved using selected cell lines and viruses. These findings suggest that the array-based platform described here is capable of detecting a broad spectrum of viruses in a single assay with relatively high sensitivity, specificity, and reproducibility. This method may be used to provide evidence of viral infection in postmortem tissue from psychiatric patients as well as a wide range of other diagnostic categories.

Autopsy↗
PubMed2004

Ontogeny and oncogenesis balance the transcriptional profile of renal cell cancer.

Global transcript analysis is increasingly used to describe cancer taxonomies beyond the microscopic reach of the eye. Diagnostic and prognostic portraits are formulated by ranking cancers according to transcriptional proximity. However, the role that distinct biological factors play in defining these portraits remains undefined. It is likely that the transcriptional repertoire of cancers depends, on one hand, on the anamnestic retention of their ontogenesis and, on the other, on the emergence of novel expression patterns related to oncogenesis. We compared the transcriptional profile of primary renal cell cancers (RCCs) with that of normal kidney tissue and several epithelial cancers of nonrenal origin to weigh the contribution that ontogeny and oncogenesis make in molding their genetic profile. Unsupervised global transcript analysis demonstrated that RCCs retain transcriptional signatures related to their ontogeny and cluster close to normal renal epithelium. When renal lineage-associated genes are removed from the analysis and cancer-specific genes are analyzed, RCCs segregate with other cancers with limited lineage specificity underlying a predominance of the oncogenic process over lineage specificity. However, a RCC-specific set of oncogenesis-related genes was identified and surprisingly shared by sarcomas. In summary, the transcriptional portrait of primary RCCs is largely dominated by ontogeny. Genes responsible for lineage specificity may represent poor molecular targets for immune or drug therapy. Most genes associated with oncogenesis are shared with other cancers and may represent better therapeutic targets. Finally, a small subset of genes is associated with lineage-specific oncogenesis, and these may provide information regarding the biological behavior of RCCs and facilitate diagnostic classification of RCCs.

Adenocarcinoma, Clear Cell↗
PubMed2004

Melanoma-restricted genes.

Human metastatic cutaneous melanoma has gained a well deserved reputation for its immune responsiveness. The reason(s) remain(s) unknown. We attempted previously to characterize several variables that may affect the relationship between tumor and host immune cells but, taken one at the time, none yielded a convincing explanation. With explorative purposes, high-throughput technology was applied here to portray transcriptional characteristics unique to metastatic cutaneous melanoma that may or may not be relevant to its immunogenic potential. Several functional signatures could be identified descriptive of immune or other biological functions. In addition, the transcriptional profile of metastatic melanoma was compared with that of primary renal cell cancers (RCC) identifying several genes co-coordinately expressed by the two tumor types. Since RCC is another immune responsive tumor, commonalities between RCC and melanoma may help untangle the enigma of their potential immune responsiveness. This purely descriptive study provides, therefore, a map for the investigation of metastatic melanoma in future clinical trials and at the same time may invite consideration of novel therapeutic targets.

Journal Article↗
PubMed2004

Selection and validation of endogenous reference genes using a high throughput approach.

BACKGROUND: Endogenous reference genes are commonly used to normalize expression levels of other genes with the assumption that the expression of the former is constant in different tissues and in different physiopathological conditions. Whether this assumption is correct it is, however, still matter of debate. In this study, we searched for stably expressed genes in 384 cDNA array hybridization experiments encompassing different tissues and cell lines. RESULTS: Several genes were identified whose expression was highly stable across all samples studied. The usefulness of 8 genes among them was tested by normalizing the relative gene expression against test genes whose expression pattern was known. The range of accuracy of individual endogenous reference genes was wide whereas consistent information could be obtained when information pooled from different endogenous reference genes was used. CONCLUSIONS: This study suggests that even when the most stably expressed genes in array experiments are used as endogenous reference, significant variation in test gene expression estimates may occur and the best normalization is achieved when data from several endogenous reference genes are pooled together to minimize minimal but significant variation among samples. We are presently optimizing strategies for the preparation of endogenous reference gene mixtures that could yield information comparable to that of data pooled from individual endogenous reference gene normalizations.

Carcinoma↗
PubMed2004

DNA array-based gene profiling in tumor immunology.

Recent advances in tumor immunology have fostered the clinical implementation of different immunotherapy modalities. However, the alternate success of such regimens underscores the fact that the molecular mechanisms underlying tumor immune rejection are still poorly understood. Given the complexity of the immune system network and the multidimensionality of tumor-host interactions, the comprehension of tumor immunology might greatly benefit from high-throughput DNA array analysis, which can portray the molecular kinetics of immune response on a genome-wide scale, thus accelerating the accumulation of knowledge and ultimately catalyzing the development of new hypotheses in cell biology. Although in its infancy, the implementation of DNA array technology in tumor immunology studies has already provided investigators with novel data and intriguing hypotheses on the cascade of molecular events leading to an effective immune response against cancer. Although the principles of DNA array-based gene profiling techniques have become common knowledge, the need for mastering this technique to produce meaningful data and correctly interpret this enormous output of information is critical and represents a tremendous challenge for investigators. In the present work, we summarize the main technical features and critical issues characterizing this powerful laboratory tool and review its applications in the fascinating field of cancer immunogenomics.

Base Sequence↗
PubMed2004

Mechanism of immune response during immunotherapy.

Tumor immunology embraces an extensive array of biological phenomena that include interactions between neoplastic cells and the innate and adaptive immune response. Among immune cells, T cells have taken the center stage because they can be easily demonstrated to specifically recognize autologous cancer cells. However, their role is limited and other components of the immune response are likely necessary for the completion of cancer rejection. Metastatic melanoma and renal cell carcinoma (RCC) are malignancies strongly predisposed to regress in response to the systemic administration of high-dose interleukin (IL)-2. Several clinical Studies in extensive cohorts of patients have shown that this treatment can induce complete or partial clinical regressions of metastatic disease in 15 to 20% of patients who receive this treatment. Although IL-2 has direct pluri-potent effects on cells with immune and inflammatory function, it remains unexplained which cell subset is implicated in mediating tumor regression. In a quest to characterize the mechanism of action of IL-2 during the course of immunotherapy, we have investigated the early changes in transcriptional profiles of circulating mononuclear cells and microenvironment of melanoma metastases following high dose IL-2 administration (720,000 IU/kg) by serial sampling of blood cells and tumors in the form of fine needle aspirate (FNA). Furthermore, studies are currently ongoing to characterize the proteomic profiling of RCC patients undergoing the same treatment using protein arrays (manuscript in preparation). The predominant activation of genes related to inflammation and activation of mononuclear phagocytes lead us to further characterize this cell subset in the context of stimulation with a panel of soluble factors potentially present in the circulation and tumor microenvironment.

Antibody Formation↗
PubMed2004

Peritoneal inflammation - A microenvironment for Epithelial Ovarian Cancer (EOC).

Epithelial ovarian cancer (EOC) is a significant cause of cancer related morbidity and mortality in women. Preferential involvement of peritoneal structures contributes to the overall poor outcome in EOC patients. Advances in biotechnology, such as cDNA microarray, are a product of the Human Genome Project and are beginning to provide fresh opportunities to understand the biology of EOC. In particular, it is now possible to examine in depth, at the molecular level, the complex relationship between the tumor itself and its surrounding microenvironment.This review focuses on the anatomy, physiology, and current immunobiologic research of peritoneal structures, and addresses certain potentially useful animal models. Changes in both the inflammatory and non-inflammatory cell compartments, as well as alterations to the extracellular matrix, appear to be signal events that contribute to the remodeling effects of the peritoneal stroma and surface epithelial cells on tumor growth and spread. These alterations may involve a number of proteins, including cytokines, chemokines, growth factors, either membrane or non-membrane bound, and integrins. Interactions between these molecules and molecular structures within the extracellular matrix, such as collagens and the proteoglycans, may contribute to a peritoneal mesothelial surface and stromal environment that is conducive to tumor cell proliferation and invasion. These alterations need to be examined and defined as possible prosnosticators and as therapeutic or diagnostic targets.

Journal Article↗
PubMed2004

Quiescent phenotype of tumor-specific CD8+ T cells following immunization.

In a human melanoma model of tumor antigen (TA)-based immunization, we tested the functional status of TA-specific CD8+ cytotoxic T lymphocytes. A "quiescent" phenotype lacking direct ex vivo cytotoxic and proliferative potential was identified that was further characterized by comparing its transcriptional profile to that of TA-specific T cells sensitized in vitro by exposure to the same TA and the T-cell growth factor interleukin 2 (IL-2). Quiescent circulating tumor-specific CD8+ T cells were deficient in expression of genes associated with T-cell activation, proliferation, and effector function. This quiescent status may explain the observed lack of correlation between the presence of circulating immunization-induced lymphocytes and tumor regression. In addition, the activation of TA-specific T cells by in vitro antigen recall and IL-2 suggests that a complete effector phenotype might be reinstated in vivo to fulfill the potential of anticancer vaccine protocols.

Antineoplastic Agents↗
PubMed2004

Forecasting the cytokine storm following systemic interleukin (IL)-2 administration.

Extensive clinical experience has shown that systemic interleukin (IL)-2 administration can induce complete or partial regression of renal cell cancer (RCC) metastases in 15 to 20 % of patients. Since IL-2 has no direct anti-cancer effects, it is believed that cancer regression is mediated either by a direct modulation of immune cell effector functions or through the mediation of soluble factors released as a result of IL-2 administration.We previously observed that transcriptional and protein changes induced by systemic IL-2 administration affect predominantly mononuclear phagocytes with little effect, particularly within the tumor microenvironment, on T cell activation, localization and proliferation. It further appeared that mononuclear phagocyte activation could be best explained by the indirect mediation of a secondary release of cytokines by IL-2 responsive cells either in the circulation or in peripheral tissues.To better characterize the cytokine outburst that follows systemic IL-2 administration we followed the serum levels of 68 soluble factors in ten patients with RCC undergoing high dose (720,000 IU/kg intravenously every 8 hours) IL-2 therapy. Serum was collected before therapy, 3 hours after the 1st and 4th dose and assayed on a multiplexed protein array platform. This study demonstrated that 1) the serum concentration of more than half the soluble factors studied changed significantly during therapy; 2) changes became more dramatic with increasing doses; 3) subclasses of soluble factors displayed different kinetics and 4) cytokine patterns varied quantitatively among patients.This study shows that the cytokine storm that follows systemic IL-2 administration is complex and far-reaching inclusive of soluble factors with disparate, partly redundant and partly contrasting effects on immune function. Therefore comparing in parallel large number of soluble factors, it sets a comprehensive foundation for further elucidation of "cytokine storm" in larger patient pools. Based on this analysis, we propose a prospective collection of serum samples in a larger cohort of patients undergoing IL-2 administration with the purpose of discerning patterns predictive of clinical outcome and toxicity.

Journal Article↗
PubMed2004

Overview of melanoma vaccines and promising approaches.

It is difficult to envision anything better than melanoma vaccines to exemplify the effectiveness of modern biotechnology in developing biologically rational therapeutics. Melanoma vaccines can reproducibly induce cytotoxic T lymphocyte (CTL) responses better than any other anticancer therapy. Anticancer vaccines have been labeled by some as ineffective for the simple reason that they only rarely lead to cancer regression. This oxymoron stems from the naïve expectation that CTLs are all that is needed to reject cancer. Little is known about requirements for CTL localization and effector function within the tumor microenvironment. In the future, more attention should be given to events downstream of immunization (afferent arm of immune response) to identify combination therapies likely to facilitate localization and activation of CTL at the receiving end (efferent arm).

Antigens, Neoplasm↗
PubMed2004

A genomic- and proteomic-based hypothesis on the eclectic effects of systemic interleukin-2 administration in the context of melanoma-specific immunization.

Among human cancers, melanoma is characterized by an almost unique predisposition to regress in response to immune therapy. Recent clinical studies suggest that the frequency of this favorable event is enhanced by combining T-cell-directed active specific immunization with the systemic administration of interleukin (IL)-2. While waiting for additional clinical experience to confirm this observation, we embraced the working hypothesis that this combination provides superior response rates than either treatment alone. In particular, we have focused our interest on the paradoxical observation that active specific immunization consistently induces circulating CD8+ T cells capable of recognizing in ex vivo assays tumor cells, but cannot induce tumor regression alone. In these settings, it appears that combining the systemic administration of IL-2 is almost an absolute requirement for the induction of clinical responses. Here, we will expand on previous speculations on the postulated mechanism(s) of action of systemic IL-2 administration and, based on original data recently derived through high-throughput transcriptional and post-translational analysis, we will suggest an explanation for the eclectic effects of IL-2 administration in the context of active specific immunization.

CD8-Positive T-Lymphocytes↗
PubMed2004

Cytokine polymorphism and its possible impact on cancer.

Human cancer is an unpredictable disease as is its response to therapy. The intrinsic genetic heterogeneity and instability of cancer cells could in part explain such behavior. However, it is possible that, individual variation in the genetic make-up of humans may affect the relationship between host and cancer cells and, therefore, be, at least in part responsible for this extraordinary variation. Human gene polymorphism has been shown indeed to play a role in immune responses; among the immune-related genes, cytokines are often polymorphic. Some polymorphisms of cytokine and cytokine receptor may have direct functional significance by altering directly and indirectly the level of gene expression and/or its function; other may only demarcate a genetic linkage to a particular haplotype associated with a given clinical condition. The majority of polymorphisms found in cytokines or their receptors are located in the promoter, intronic and 3' untranslated regions. These sequence variations can still affect gene expression and function. In this review will we summarize the current knowledge about the role of cytokine polymorphism in disease and more specifically in cancer.

3' Untranslated Regions↗
PubMed2004

18th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer. 30 October-2 November 2003, Bethesda, Maryland, USA.

The 18th Annual Scientific Meeting of the International Society for Biological Therapy of Cancer (iSBTc) was held at the Hyatt Regency, Bethesda, MD, close to the National Institutes of Health (NIH) campus. The meeting was organised on behalf of the society by Neil Berinstein from Aventis Pasteur, Toronto, Canada, Janice P Dutcher from Our Lady of Mercy Medical Center, Bronx, NY and Francesco M Marincola from the NIH, Bethesda, MD. The 2003 meeting included 57 oral presentations and > 100 poster presentations. There were > 800 registrants to the Annual Meeting and the multiple satellite symposia. The iSBTc, formerly the Society of Biological Therapy (SBT), was founded by R Oldham in 1984. Its membership has been rapidly growing of late, with > 500 members at present. The purpose of the iSBTc is to bring together those diverse individuals actively investigating biologic agents and biological response modifiers in the treatment of cancer, including clinicians and basic scientists from industry, government and academia. The President of the Society is Dr Michael B Atkins from Beth Israel Deaconess Medical Center, Boston, MA and the Vice President is Ulrich Keilholz from UKBF, Free University Berlin, Germany.

Animals↗
PubMed2004

Vaccination with T cell-defined antigens.

Tumour immunology encompasses a broad array of biological phenomena including interactions between neoplastic cells and the innate and adaptive immune response. Among immune cells, T cells have taken the centre stage because they can be easily demonstrated to specifically recognise autologous cancer cells. As most tumour-associated antigens are intracellular proteins, T cells appear to be the most suitable tool for cancer-specific attack, as antibodies do not cross the cell membrane and the innate immune response lacks the same level of specificity. Finally, the relative ease in which T cells can be educated through antigen-specific immunisation to recognise cancer cells has elevated them to an even higher stature. In this review, it will be argued that T cells represent a unique anticancer agent, characterised by absolute specificity. Although other therapeutic modalities (antibody-based) have been effectively implemented, a comparison of T cell-based approaches with other modalities goes beyond the purposes of this review and will not be included in the discussion. However, it is obvious that the role of the T cell is limited and other components of the immune response (effector mononuclear phagocytes, natural killer cells, cytokines, chemokines, soluble factors), genetic background and tumour heterogeneity are likely to be necessary for the completion of cancer rejection.

Animals↗