Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The identification of many tumor-associated epitopes as nonmutated "self" Ags led to the hypothesis that the induction of large numbers of self/tumor Ag-specific T cells would be prevented because of central and peripheral tolerance. We report in this study on vaccination efforts in 95 HLA-A*0201 patients at high risk for recurrence of malignant melanoma who received prolonged immunization with the "anchor-modified" synthetic peptide, gp100209-217(210M). Vaccination using this altered peptide immunogen was highly effective at inducing large numbers of self/tumor-Ag reactive T cells in virtually every patient tested, with levels as high as 42% of all CD8+ T cells assessed by tetramer analysis. From 1 to 10% of all CD8+ cells were tumor-Ag reactive in 44% of patients and levels >10% were generated in 17% of patients. These studies were substantiated using the ELISPOT assay and a bulk cytokine release assay. Although our data regarding "tumor escape" were inconclusive, some patients had growing tumors that expressed Ag and HLA-A*0201 in the presence of high levels of antitumor T cells. There was no difference in the levels of antitumor Ag-specific T cells in patients who recurred compared with those that remained disease-free. Thus, the mere presence of profoundly expanded numbers of vaccine-induced, self/tumor Ag-specific T cells cannot by themselves be used as a "surrogate marker" for vaccine efficacy. Further, the induction of even high levels of antitumor T cells may be insufficient to alter tumor progression.
 ...
PMID:Tumor progression can occur despite the induction of very high levels of self/tumor antigen-specific CD8+ T cells in patients with melanoma. 1658 36

Dendritic cell (DC) defects are an important component of immunosuppression in cancer. Here, we assessed whether cancer could affect circulating DC populations and its correlation with tumor progression. The blood DC compartment was evaluated in 136 patients with breast cancer, prostate cancer, and malignant glioma. Phenotypic, quantitative, and functional analyses were performed at various stages of disease. Patients had significantly fewer circulating myeloid (CD11c+) and plasmacytoid (CD123+) DC, and a concurrent accumulation of CD11c(-)CD123(-) immature cells that expressed high levels of HLA-DR+ immature cells (DR(+)IC). Although DR(+)IC exhibited a limited expression of markers ascribed to mature hematopoietic lineages, expression of HLA-DR, CD40, and CD86 suggested a role as antigen-presenting cells. Nevertheless, DR(+)IC had reduced capacity to capture antigens and elicited poor proliferation and interferon-gamma secretion by T-lymphocytes. Importantly, increased numbers of DR(+)IC correlated with disease status. Patients with metastatic breast cancer showed a larger number of DR(+)IC in the circulation than patients with local/nodal disease. Similarly, in patients with fully resected glioma, the proportion of DR(+)IC in the blood increased when evaluation indicated tumor recurrence. Reduction of blood DC correlating with accumulation of a population of immature cells with poor immunologic function may be associated with increased immunodeficiency observed in cancer.
 ...
PMID:A population of HLA-DR+ immature cells accumulates in the blood dendritic cell compartment of patients with different types of cancer. 1635 94

The 5T4 oncofetal antigen is expressed by a wide variety of human carcinomas, including colorectal, ovarian and gastric carcinomas. The restricted expression of 5T4 on tumor tissues as well as its implication in tumor progression and bad prognosis makes 5T4 a promising new candidate for immunotherapy. An MVA vaccine encoding 5T4 antigen has been successfully evaluated in preclinical studies in a murine tumor model. Here, we report the generation of human CD8 T cells specific for the 5T4 antigen by stimulation with autologous monocyte derived DC infected with a replication defective adenovirus encoding the 5T4 cDNA (Ad5T4). Analysis of several donors confirms a repertoire of such CD8 responses. In a parallel approach, incorporating the results of proteasome-mediated digestion of 5T4 derived 35-mer peptides and the potential high affinity epitopes predicted by a computer-based algorithm, we identified 8 putative HLA-A*0201-presented CD8 MHC class I epitopes of 5T4 antigen. Two of these generated specific CD8 T cells after restimulation with peptide loaded autologous DC and assay by cytotoxicity and IFN gamma ELISPOT. Moreover these particular peptide generated T cells recognized naturally 5T4 positive tumor cells only if they expressed HLA-A*0201 as judged by IFN gamma ELISPOT or ELISA. Also, HLA-A*0201 CD8 T cells recognized these peptides in a DC-Ad5T4 polyclonal response. In conclusion, there is a repertoire of CD8 T cell recognition of 5T4 in normal human donors and some candidate HLA-A*0201 epitopes have been identified.
 ...
PMID:CD8 T-cell recognition of human 5T4 oncofetal antigen. 1664 78

Alterations in HLA class I antigen expression have been frequently described in different epithelial tumors and are thought to favor tumor immune escape from T lymphocyte recognition. Multiple molecular mechanisms are responsible for these altered HLA class I tumor phenotypes. Some are structural defects that produce unresponsiveness to treatment with interferons. Others include alterations in regulatory mechanisms that can be switched on by treatment of tumor cells with different cytokines. One important mechanism belonging to the first group is loss of heterozygosity (LOH) at chromosome region 6p21.3, which can lead to HLA haplotype loss. In this investigation, the frequency of LOH at 6p21 chromosome region was studied in 69 bladder carcinomas. Short tandem repeat analysis showed that 35% of cases had LOH in this chromosome region. By considering these results together with immunohistological findings previously published by our group, we identified a distribution pattern of HLA class I altered phenotypes in bladder cancer. The most frequently altered phenotype in bladder carcinomas was total loss of HLA class I expression (17 cases, 25%), followed by phenotype II associated with HLA haplotype loss (12 cases, 17.5%), and HLA allelic loss (ten cases, 14.5%). Nine cases (13%) were classified as having a compound phenotype, five cases (7%) as having HLA locus loss, and in 16 cases (23%) no alteration in HLA expression was detected. An important conclusion of this report is that a combination of different molecular and immunohistological techniques is required to precisely define which HLA alleles are lost during tumor progression and to characterize the underlying mechanisms of these losses. These studies should be performed when a cancer patient is to be included in an immunotherapy protocol that aims to stimulate different immune effector mechanisms.
 ...
PMID:LOH at 6p21.3 region and HLA class I altered phenotypes in bladder carcinomas. 1670 7

Studies aimed at elucidating the immunological and prognostic significance of HLA-DR expression on breast carcinoma cells have yielded contradictory results. To expand on previous studies, we have investigated the associations of tumor cell expression of HLA-DR and its related co-chaperones, invariant chain (Ii) and HLA-DM, with infiltrating inflammatory cells, in situ cytokine mRNA levels and prognosis and outcome in 112 breast carcinoma patients with a median follow-up of 59 months. While the majority of HLA-DR+ tumors co-express Ii, only a minority express HLA-DM. Tumor cell expression of HLA-DR and co-chaperones positively associated with both infiltrating CD4+ and CD8+ T-cell subsets (P < 0.01). Expression of HLA-DR and Ii associated with decreased estrogen receptor alpha levels and younger age at diagnosis, suggesting a role for hormones in the control of HLA class II expression in breast carcinoma. Patients with DR+Ii+DM- tumors had markedly decreased recurrence-free and disease-specific survival as compared with patients with DR+Ii+DM+ tumors (P < 0.05) and HLA-DR/co-chaperone expression was an independent predictor of survival by multivariate Cox regression analysis, controlling for standard prognostic indicators. Tumors that co-express HLA-DR, Ii and HLA-DM have increased levels of IFN-gamma, IL-2 and IL-12 mRNA, suggesting improved survival of patients with DR+Ii+DM+ tumors may be attributable to Th1-dominated immunity. We conclude that expression of determinants of the immune response by tumor cells may influence breast tumor progression and patient outcome.
 ...
PMID:Tumor cell expression of HLA-DM associates with a Th1 profile and predicts improved survival in breast carcinoma patients. 1698 35

A clinical significance of the aberrant expression of HLA class I molecules including HLA class I and HLA-G was analyzed using tissue array analysis. Our institute has established a two millimeter spot sized tissue array set of 105 clinical cases of resected human non small cell lung cancer tissues. A loss of HLA class I was observed in the 58.3% of cancer tissues. The aberrant expression of HLA G was also observed in the 55.2% of cancer tissues. Statistically significant correlations were observed among HLA class I expression and tumor size, nodal involvement and pathological stage. Survival analyses were shown that the HLA class I loss was correlated to a recurrence free survival time. The HLA-G expression did not correlate with any clinico-pathological parameters. A loss of HLA class I was probably involved due to a cancer progression in human non-small cell lung cancer through the mechanism of immune escape from the host immune system.
 ...
PMID:[Tissue array analysis of the aberrant expression of HLA class I molecules in human non small cell lung cancer]. 1721 84

To avoid immune escape by down-regulation or loss of Ag by the tumor cells, target Ags are needed, which are important for the malignant phenotype and survival of the tumor. We could identify a CD4(+) T cell epitope derived from the human melanoma-associated chondroitin sulfate proteoglycan (MCSP) (also known as high m.w.-melanoma-associated Ag), which is strongly expressed on >90% of human melanoma lesions and is important for the motility and invasion of melanoma cells. However, MCSP is not strictly tumor specific, because it is also expressed in a variety of normal tissues. Therefore, self tolerance should prevent the induction of strong T cell responses against these Ags by vaccination strategies. In contrast, breaking self tolerance to this Ag by effectively manipulating the immune system might mediate antitumor responses, although it would bear the risk of autoimmunity. Surprisingly, we could readily isolate CD4(+) Th cells from the blood of a healthy donor-recognizing peptide MCSP(693-709) on HLA-DR11-expressing melanoma cells. Broad T cell reactivity against this Ag could be detected in the peripheral blood of both healthy donors and melanoma patients, without any apparent signs of autoimmune disease. In some patients, a decline of T cell reactivity was observed upon tumor progression. Our data indicate that CD4(+) T cells are capable of recognizing a membrane glycoprotein that is important in melanoma cell function, and it may be possible that the sizable reactivity to this Ag in most normal individuals contributes to immune surveillance against cancer.
 ...
PMID:Tumor-reactive CD4+ T cell responses to the melanoma-associated chondroitin sulphate proteoglycan in melanoma patients and healthy individuals in the absence of autoimmunity. 1754 7

S100A7 (psoriasin) is highly expressed in preinvasive breast carcinomas and in a subset of poor prognosis invasive tumors. To determine the influence of S100A7 expression on ERalpha negative breast cancer, we profiled mRNA gene expression by Microarray and SAGE analysis, using the ERalpha negative MDA-MB-231 cell line model. Statistically significant transcripts of genes with very high differential expression were further validated by QPCR in both MDA-MB-231 and MDA-MB-468 cell lines expressing exogenous and endogenous S100A7. S100A7 expression correlated with increases in genes associated with MHC class II receptor activity, antigen processing and antigen presentation, and immune cell activation. The transcription factors (TFs) prediction tool CARRIE confirmed an association between TFs reported to be upregulated by S100A7 (NF-kappaB, AP-1, and HIF1) and the regulation of many genes in this dataset. The relationship between S100A7 up-regulation and the MHC class II and HLA-class II molecule coding gene CD74 was examined further in a cohort of ERalpha negative breast tumors by tissue microarray (TMA) and immunohistochemistry (IHC), confirming a significant association in vivo (p=0.042, n=149). These results are consistent with a role for S100A7 in modulating the immune response which may be a factor in early breast tumor progression.
 ...
PMID:S100A7 (psoriasin) influences immune response genes in human breast cancer. 1756 May 71

Loss of HLA class I expression on tumor cells is a frequent event as an immune escape mechanism. Seven different altered HLA phenotypes have been defined in tumors. Various molecular mechanisms have been described as responsible for HLA class I loss. HLA class I expression alterations occur successively and unpredictably during tumor progression in vivo and immunoselection has been implicated in this process. We present an experimental xenograft model in which melanoma cell line Ando-2 injected into athymic nude mice lost total surface HLA class I expression and exhibited HLA class II cell surface expression. A strong down-regulation of HLA class I expression and de novo HLA class II expression were also found when Ando-2 melanoma cells were injected into SCID-Beige mice. These phenomena were reproducible and were only observed in local growth in nude or SCID-Beige mice and not in vitro after multiple passages. HLA class I surface expression was recovered after IFN-gamma treatment, indicating regulatory defects. The mechanism implicated in loss of HLA class I molecule expression were a down-regulation of different components of antigen processing machinery and HLA class I heavy chains. These data suggest that HLA class I alterations can also occur in absence of autologous adaptive immune response. This is a good experimental in vivo model to study the relationship between tumor progression and HLA class I alterations.
 ...
PMID:Total loss of HLA class I expression on a melanoma cell line after growth in nude mice in absence of autologous antitumor immune response. 1762 28

Immunotherapy with whole cell cancer vaccines has been tested in various tumor types. This study investigated the safety profile and antitumor activity of an allogeneic prostate carcinoma cell line, LNCaP, expressing recombinant human interleukin-2 and human interferon-gamma. Thirty HLA-A*0201-matched patients with progressive, castration-resistant prostate cancer received four intradermal injections on days 1, 15, 29, and 92, and then every 90 days, as long as no tumor progression occurred. Three patients received a dose level of 7.5 million cells, and 27 patients received 15 million cells per injection. The primary study criteria were safety and the difference in prostate-specific antigen doubling time (PSA-DT), determined in the pretreatment phase (before the start of vaccination) and in the trial treatment phase (during vaccination). No dose-limiting or autoimmune toxicity was seen. During vaccination there was a significant prolongation of the PSA-DT compared with the prevaccination period (prolongation from 63 to 114 days; p < 0.01; intention to treat). In addition, results showed a period of PSA stabilization of at least 12 weeks, together with stable bone scans in 12 of 30 patients, and 3 patients sustained a >50% decrease in PSA versus baseline. The median overall survival time from first vaccination was 32 months (mean value, 34 months). Immune monitoring revealed T cell stimulation in the majority of patients. This vaccine strategy was found to be safe and well tolerated and was accompanied by prolongation of PSA-DT. The results of this trial warrant clinical development of this vaccine.
 ...
PMID:Therapeutic vaccination with an interleukin-2-interferon-gamma-secreting allogeneic tumor vaccine in patients with progressive castration-resistant prostate cancer: a phase I/II trial. 1967 Oct


<< Previous 1 2 3 4 5 6 7 8 9 Next >>