The effects of diet and carcinogen on the natural killer cell activity of sprague dawley rats.

This study was conducted to determine if dietary fat and/or administration of 7,12 dimethylbenz((alpha))anthracene (DMBA) to Sprague Dawley rats affected the natural killer cell activity of these animals.There was no difference in the level of inhibitory activity of NK cells from rats on a low fat diet compared to rats on the high fat diet, when the R(, 2)T(, 2) tumor cell line was used as the target cell.The proliferative activity of NK cells was generally higher in rats on the high fat diet compared to rats on the low fat diet. NK-induced inhibition of YAC-1 cell proliferation correlated inversely with the proliferative activity of the NK cells. Some of the rats fed high fat diets had NK cells whose proliferative activity was approximately twice that of rats fed low fat diets, and whose corresponding inhibitory activity against YAC-1 tumor cells was one-half that of rats on low fat diets.The inhibitory activity of NK cells was dependent on the quantity of fat in the diet of the rats from which these cells were obtained. Rats which were fed a 20% corn oil diet (high fat) generally had lower levels of inhibitory activity against YAC-1 tumor cells compared to rats fed a diet containing 2% linoleic acid (low fat). While choline deficiency or treatment with DMBA did not alter NK cell activity in either dietary group, the combination of both factors caused a significant reduction in NK cell activity when rats were maintained on a high fat diet.The incorporation of ('3)H-thymidine into YAC-1 tumor cells was inhibited when Percoll separated, rat spleen cell fractions, and unseparated spleen cells were cultured with YAC-1 tumor cells.NK cell activity was not constant during the period of study, but tended to display cyclic responses, particularly in rats in the high fat diet.While the ability of NK cells to inhibit proliferation of YAC-1 tumor cells in vitro was diet dependent, the inability to show diet dependency on the ability of NK cells to inhibit the proliferation of R(, 2)T(, 2) tumor cells in vitro did not necesssarily rule out an in vivo role for NK cells in the resistance of rats to DMBA-induced tumors

Cancer-Associated Fibroblasts Modulate Transcriptional Signatures Involved in Proliferation, Differentiation and Metastasis in Head and Neck Squamous Cell Carcinoma

Cancer-associated fibroblasts (CAFs) are known to increase tumor growth and to stimulate invasion and metastasis. Increasing evidence suggests that CAFs mediate response to various treatments. HNSCC cell lines were co-cultured with their patient-matched CAFs in 2D and 3D in vitro models, and the tumor cell gene expression profiles were investigated by cDNA microarray and qRT-PCR. The mRNA expression of eight candidate genes was examined in tumor biopsies from 32 HNSCC patients and in five biopsies from normal oral tissue. Differences in overall survival (OS) were tested with Kaplan–Meier long-rank analysis. Thirteen protein coding genes were found to be differentially expressed in tumor cells co-cultured with CAFs in 2D and 81 in 3D when compared to tumor cells cultured without CAFs. Six of these genes were upregulated both in 2D and 3D (POSTN, GREM1, BGN, COL1A2, COL6A3, and COL1A1). Moreover, two genes upregulated in 3D, MMP9 and FMOD, were significantly associated with the OS. In conclusion, we demonstrated in vitro that CAF-derived signals alter the tumor cell expression of multiple genes, several of which are associated with differentiation, epithelial-to-mesenchymal transition (EMT) phenotype, and metastasis. Moreover, six of the most highly upregulated genes were found to be overexpressed in tumor tissue compared to normal tissue

Cancer-Associated Fibroblasts Modulate Transcriptional Signatures Involved in Proliferation, Differentiation and Metastasis in Head and Neck Squamous Cell Carcinoma

Cancer-associated fibroblasts (CAFs) are known to increase tumor growth and to stimulate invasion and metastasis. Increasing evidence suggests that CAFs mediate response to various treatments. HNSCC cell lines were co-cultured with their patient-matched CAFs in 2D and 3D in vitro models, and the tumor cell gene expression profiles were investigated by cDNA microarray and qRT-PCR. The mRNA expression of eight candidate genes was examined in tumor biopsies from 32 HNSCC patients and in five biopsies from normal oral tissue. Differences in overall survival (OS) were tested with Kaplan–Meier long-rank analysis. Thirteen protein coding genes were found to be differentially expressed in tumor cells co-cultured with CAFs in 2D and 81 in 3D when compared to tumor cells cultured without CAFs. Six of these genes were upregulated both in 2D and 3D (POSTN, GREM1, BGN, COL1A2, COL6A3, and COL1A1). Moreover, two genes upregulated in 3D, MMP9 and FMOD, were significantly associated with the OS. In conclusion, we demonstrated in vitro that CAF-derived signals alter the tumor cell expression of multiple genes, several of which are associated with differentiation, epithelial-to-mesenchymal transition (EMT) phenotype, and metastasis. Moreover, six of the most highly upregulated genes were found to be overexpressed in tumor tissue compared to normal tissue

Cytotoxic dendritic cells generated from cancer patients.

International audienceKnown for years as professional APCs, dendritic cells (DCs) are also endowed with tumoricidal activity. This dual role of DC as killers and messengers may have important implications for tumor immunotherapy. However, the tumoricidal activity of DCs has mainly been investigated in animal models. Cancer cells inhibit antitumor immune responses using numerous mechanisms, including the induction of immunosuppressive/ tolerogenic DCs that have lost their ability to present Ags in an immunogenic manner. In this study, we evaluated the possibility of generating tumor killer DCs from patients with advanced-stage cancers. We demonstrate that human monocyte-derived DCs are endowed with significant cytotoxic activity against tumor cells following activation with LPS. The mechanism of DC-mediated tumor cell killing primarily involves peroxynitrites. This observed cytotoxic activity is restricted to immature DCs. Additionally, after killing, these cytotoxic DCs are able to activate tumor Ag-specific T cells. These observations may open important new perspectives for the use of autologous cytotoxic DCs in cancer immunotherapy strategies

Application of Social Network Analysis to Health Care Sectors

Objectives: This study aimed to examine the feasibility of social network analysis as a valuable research tool for indicating a change in research topics in health care and medicine. Methods: Papers used in the analysis were collected from the PubMed database at the National Library of Medicine. After limiting the search to papers affiliated with the National Institutes of Health, 27,125 papers were selected for the analysis. From these papers, the top 100 non-duplicate and most studied Medical Subject Heading terms were extracted. NetMiner V.3 was used for analysis. Weighted degree centrality was applied to the analysis to compare the trends in the change of research topics. Changes in the core keywords were observed for the entire group and in three-year intervals. Results: The core keyword with the highest centrality value was “Risk Factor, ” followed b

Role of tumor architecture in elicitation of effector functions of human cytotoxic T-lymphocytes recognizing melanoma associated antigens

Growth in 3D architectures has been shown to promote the resistance of cancers to treatment with drugs, cytokines, or irradiation, thereby potentially playing an important role in tumor expansion. 3D architectures might also play a role in impairing immunorecognition of cancer cells by cytotoxic T lymphocytes (CTLs) specific for tumor-associated antigens. Culture of HBL, D10 (both HLA-A*0201+, TAA+) and NA8 (HLA-A*0201+, TAA-) melanoma cell lines on poly-Hydroxyethylmethacrylate-coated plates, resulted in generation of 3D multicellular tumor spheroids (MCTS). Kinetics of cell proliferation in MCTS was significantly slower than in monolayer cultures. Following long-term culture (>10-15 days) MCTS showed highly compact and organised cell growth in outer layers, with necrotic cores. To obtain an insight into the role played by tumor architecture in the elicitation of specific gene expression patterns, we addressed gene expression profiles of NA8 melanoma cells cultured in two-dimensional monolayers (2D) or in 3D (MCTS). Oligonucleotide microarray analysis of the expression of over 20,000 genes was performed on cells cultured in standard 2D, in the presence of collagen as model of extracellular matrix (ECM), or in MCTS. Gene expression profiles of cells cultured in 2D in the presence or absence of ECM were highly similar, with more than threefold differences limited to five genes. In contrast, culture in MCTS resulted in the significant, more than threefold, upregulation of the expression of >100 transcripts, while 73 transcripts were more than threefold downregulated. In particular, genes encoding CXCL1, 2, and 3 (GRO-α, -β, and γ), IL-8, CCL20 (MIP-3α), and Angiopoietin-like 4 were significantly upregulated, whereas basic-FGF and CD49d encoding genes were significantly downregulated. Oligonucleotide chip data were validated at the gene and protein level by quantitative real-time PCR, ELISA, and cell surface staining assays. Taken together, our data indicate that structural modifications of the architecture of tumor cell cultures result in a significant upregulation of the expression of a number of genes previously shown to play a role in melanoma progression and metastatic process. Then we investigated the effects of 3D culture on the recognition of melanoma cells by antigenspecific HLA class I-restricted Cytotoxic T-Lymphocytes (CTL). IFN-γ production can be used as a surrogate marker for tumor cell immunorecognition. Co-culture of melanoma spheroids with HLA-A0201 restricted Melan-A/MART-127-35-specific CTL clones resulted in significantly defective TAA recognition by CTL as compared to 2D, as witnessed by decreased IFN-γ production and decreased Fas Ligand, perforin and granzyme B gene expression. Indeed, Melan- A/MART-1 expression, at both gene and protein levels, was significantly decreased in 3D as compared with 2D tumor cell cultures. Concomitantly, a parallel decrease of HLA class I molecule expression was also observed. Differential gene profiling studies on HBL cells showed an increased expression of genes encoding molecules involved in intercellular adhesion, such as junctional adhesion molecule 2 and cadherin-like 1 (>20- and 8-fold up-regulated, respectively) in 3D as compared with 2D cultures. We further identified a multiplicity of mechanisms potentially involved. In particular : 1) MCTS per se limit CTL capacity of recognizing HLA class I restricted antigens by reducing exposed cell surfaces. 2) Expression of melanoma differentiation antigens is down-regulated in tumor cell spheroids as compared to 2D unrelated to hypoxia or increased Oncostatin M gene expression but rather to decreased MITF gene expression. 3) Expression of HLA class I molecules is frequently down-regulated in melanoma MCTS, as compared to 2D, possibly due to decreased IRF-1 gene expression. 4) Lactate production by melanoma cells is increased in MCTS, as compared to 2D and lactate significantly inhibits TAA triggered IFN-γ production by CTL. Taken together, our data suggest that mere growth of melanoma cells in 3D architectures, in the absence of immunoselective pressure, may result in defective recognition by tumor-associated antigen-specific CTL and a constellation of mechanisms are involved in causing this impairment of immunorecognition

von Hippel-Lindau Disease-Associated Hemangioblastomas Are Derived from Embryologic Multipotent Cells

BACKGROUND: To determine the origin of the neoplastic cell in central nervous system (CNS) hemangioblastomas in von Hippel-Lindau disease (VHL) and its role in tumor formation and distribution, we characterized and differentiated neoplastic cells from hemangioblastomas removed from VHL patients. METHODS AND FINDINGS: A total of 31 CNS hemangioblastomas from 25 VHL patients were resected and analyzed. Tumor cells from the hemangioblastomas were characterized, grown, and differentiated into multiple lineages. Resected hemangioblastomas were located in the cerebellum (11 tumors), brainstem (five tumors), and spinal cord (15 tumors). Consistent with an embryologically derived hemangioblast, the neoplastic cells demonstrated coexpression of the mesodermal markers brachyury, Flk-1 (vascular endothelial growth factor-2), and stem cell leukemia (Scl). The neoplastic cells also expressed hematopoietic stem cell antigens and receptors including CD133, CD34, c-kit, Scl, erythropoietin, and erythropoietin receptor. Under specific microenvironments, neoplastic cells (hemangioblasts) were expanded and differentiated into erythrocytic, granulocytic, and endothelial progenitors. Deletion of the wild-type VHL allele in the hematopoietic and endothelial progeny confirmed their neoplastic origin. CONCLUSIONS: The neoplastic cell of origin for CNS hemangioblastomas in VHL patients is the mesoderm-derived, embryologically arrested hemangioblast. The hematopoietic and endothelial differentiation potential of these cells can be reactivated under suitable conditions. These findings may also explain the unique tissue distribution of tumor involvement