PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cancer immunotherapy”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Prospects and limitations of recombinant poxviruses for prostate cancer immunotherapy.

Prostate cancer is a disease that may be amenable to immunotherapy approaches, as evidenced by the ability to induce human cytotoxic immune responses against prostate cancer cells. Recent interest in recombinant poxvirus vaccines coupled with the need for new prostate cancer therapies has led to the development of several recombinant poxvirus agents designed for prostate cancer treatment. Whether these agents will be effective in treating prostate cancer is under investigation in several ongoing and upcoming clinical trials. In the meantime, data from preclinical tumor models have provided information that may aid in improving recombinant poxviruses for clinical use. While animal studies have shown the ability of recombinant poxvirus vaccination to induce an immune response that protects against lethal tumor, these antitumor effects are variable and depend on a number of factors. Co-expression of immunomodulating gene products, such as cytokines and costimulatory molecules, have been shown to influence antitumor immunity; in fact, cytokine delivery alone can be enough to protect against tumor-related death. Patterns and levels of recombinant antigen expression also affect the immune response to that antigen, as seen by studies of various poxvirus promoters and cell compartment-targeting sequences. In addition, vaccine strategies targeting self-antigens have shown that immunological tolerance can negatively impact the induction of antitumor and antigen-specific immunity. Although vaccinia virus has been most intensely studied thus far, other poxviruses, including fowlpox and canarypox, are also promising vaccine candidates. These alternative vectors may circumvent some of the disadvantages associated with vaccinia virus, such as pre-existing vaccinia immunity. A deeper understanding of these factors and others that impact the development of antitumor immunity will be necessary to guide the development of recombinant poxviruses for prostate cancer therapy.

Adenocarcinoma↗

Peptide-based vaccines for cancer immunotherapy.

One approach in the immunotherapy of cancer patients involves vaccination with peptides derived from tumour-associated antigens specifically designed to associate with T cells in the context of major histocompatibility complex (MHC) class I or II molecules. Several clinical trials in different tumour types have been conducted utilising this vaccination strategy. The majority of trials indicate that peptide vaccination has few toxicities associated with its administration, but disparities exist between in vitro and clinical responses. However, this represents an evolving field and, thus, it is difficult to draw firm conclusions concerning the efficacy of peptide-based vaccines for cancer immunotherapy. Improvements to peptide vaccination, including the addition of various adjuvants, the utilisation of peptide-pulsed dendritic cells, multipeptide vaccinations, the addition of helper peptides and peptide delivery through the use of mini-genes, are encouraging and serve as important guides for future research.

Adjuvants, Immunologic↗

Surrogate markers of response to cancer immunotherapy.

Clinically effective cancer immunotherapy has been sought for more than 100 years and has been recently applied most successfully in strategies that passively deliver immune effectors such as monoclonal antibodies (anti-CD20 for lymphoma and anti-HER2/neu for breast cancer), donor lymphocyte infusions in chronic myelongenous leukemia and non-myeloablative allogeneic peripheral blood progenitor transplants for renal cell carcinoma. There is mounting enthusiasm for strategies employing active stimulation of antitumour immune responses. These include vaccines based on tumour antigen proteins and peptides, autologous, allogeneic or gene-modified tumour cells, dendritic cells and antigen-encoding viral vector constructs. Indeed, randomised Phase III clinical trials of autologous tumour cell vaccines for colorectal cancer demonstrated an improvement in disease free survival and a trend toward improved overall survival [1]. Despite these preliminary successes, it is clear that the many strategies under development cannot all be evaluated for survival benefit in large clinical trials that require many years, patients and resources to complete. This highlights the need to develop intermediate markers to help prioritise which agents to test in prospective randomised Phase III trials.

Biomarkers↗

Dendritic cell-based cancer immunotherapy: potential for treatment of colorectal cancer?

Human tumours including those of the gastrointestinal tract express a number of specific antigens that can be recognized by T cells, thus providing potential targets for cancer immunotherapy. Dendritic cells (DC) are rare leucocytes that are uniquely potent in their ability to capture, process and present antigens to T cells, and so selectively migrate through tissues to reach lymph nodes and spleen where initiation of immune responses takes place. Studies in murine tumour models have shown clearly that DC are capable of presenting tumour antigens to initiate tumour-specific cytotoxic T cell responses, and DC vaccination can induce anti-tumour activity against both primary tumours and pre-established tumour metastases. These findings together with the ability to culture sufficient numbers of DC from human bone marrow or blood progenitors have prompted the current major interest in their potential use in human tumour vaccination. Vaccine production involves harvesting autologous DC from cultured peripheral blood mononuclear cells in the presence of a cocktail of cytokines, ex vivo exposure of the DC to tumour antigens and return of pulsed DC to the patient to induce tumour immunity. Reports from Phase I/II clinical trials indicate that DC vaccines are safe with little or no side effect, and are capable of initiating antigen-specific T cell responses. Furthermore, defined tumour antigens are not necessarily required, which may make the process more applicable to human cancers, including many gastrointestinal cancers that lack well-characterized tumour-specific antigens. Additional trials of DC vaccination for a variety of human cancers including colorectal cancers are under way, and refinement of vaccine protocols and methods for targeting tumour antigens to DC in vivo are also being explored. There is reason to believe that DC-based vaccination could become an adjunct to current treatments for human cancers including colorectal cancer in the foreseeable future.

Clinical Trials as Topic↗

Lessons from past experience in cancer immunotherapy and their application to cancer and AIDS treatment and prophylaxis.

Passive immunotherapy which we attempted in 1957 using polyclonal antibodies from immunized donors aggravated tumor evolution: we suspected that blocking by Ig, tumor cell antigen epitopes which are necessary to enhance or even maintain the T-lymphocyte effector role in anti-cancer immunity could be the reason for this tumor aggravation by "specific" antibodies. Today the very limited results of monoclonal antibodies in cancer treatment favors this hypothesis. The aggravation of HIV by (some) antibodies suggests that the same phenomenon may also happen in this condition. In 1957, on the other hand, we described the therapeutically beneficial cytostatic targetting effect of polyclonal antibodies, an effect which has often been quoted and widely confirmed. Does the reason for the poor results of monoclonal antibody targetting in tumor treatment reside in cancer antigen heterogeneity? This is what an experiment we conducted with Olsson on AkR leukemia indicated, suggesting that several monoclonals should be simultaneously combined for most patients, to be determined by the antigenic study not only of each tumor but of each localisation. We shifted our cancer immunotherapy approach to an adoptive form in 1959; a), after establishing partial and transient, then total and permanent allogeneic marrow graft and chimerism in man; b), after describing the graft versus leukemia (GvL) action of the graft versus host (GvH) effect in leukaemic mice; c), and the same phenomenon in humans. Our observations on human allogeneic grafted bone marrow GvH and GvL were statistically confirmed in 1979 by the Seattle group. In the 1970s we attempted to induce strong GvL with weak GvH by replacing allogeneic bone marrow graft by allogeneic lymphocyte transfusions without host conditioning. Remarkable results were registered in mice, and in patients with acute leukaemia--5 complete remissions out of 7 patients who developed moderate GvH, and only 3 out of 70 in those who did not develop GvH. As we now know that CD4-, CD8+ lymphocytes are not all MHCl-restricted, we consider that the allogeneic CTL approach is worth trying as reinforcement treatment of (at least) severe hematopoietic malignancies. If it is indeed worthwhile in some severe neoplasias to include the adoptive form of immunotherapy in the multi-treatment program, the replacement of the patient's bone marrow by engrafted allogeneic stem cells has not been proven necessary, as the persistence in "ALL cured" chemotherapy patients of abnormally differentiated cells does not reduce the expectancy of cure.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗

In vitro propagated dendritic cells from prostate cancer patients as a component of prostate cancer immunotherapy.

T cell-mediated cancer immunotherapy requires efficient antigen-presenting cells. Dendritic cells (DCs) are arguably the most efficient antigen-presenting cells studied to date. Individuals with prostate cancer often undergo various therapies which may compromise their immune system, including the state of their DC precursors. We report the in vitro propagation of DCs from peripheral blood of patients with prostate cancer, most of whom are in clinical stages D1 or D2 and have undergone radiation therapy. After 7 days in culture, the number of DCs recovered were 20-50-fold higher than those isolated directly from peripheral blood. This number is comparable to findings of previous studies with healthy individuals. Cultured patients' DCs were capable of presenting tetanus toxoid to autologous T cells in vitro. Furthermore, T cells from 2 of 4 patients proliferated when cultured with their DCs and the lysate of a human prostate cancer cell line (LNCaP), demonstrating the potential role of autologous DCs in prostate cancer immunotherapy studies.

Aged↗

MUC1 as a target antigen for cancer immunotherapy.

The cancer-associated antigen MUC1 is overexpressed and modified by tumor cells in over half of all cancer cases. Despite various complexities associated with this antigen, it is well worth pursuing as a vaccine for the immunotherapy of cancer. In this review, the authors describe the discovery of MUC1 and its association with cancer, recent observations showing that the immunology of MUC1 is complicated, animal data showing that it can be a target for immune-mediated tumor rejection, and finally, preliminary clinical results to show that vaccine-based immunotherapy with MUC1 does have an impact on the therapy of cancer.

Animals↗

Monocyte/macrophages as effector cells in cancer immunotherapy.

Among the different strategies which have been developed for immunotherapy of cancer, adoptive immunotherapy uses leucocytes activated in vitro and reinfused into the patients. Five leucocytes subsets can be employed for this immunotherapy with activated autologous cells. Blood monocytes can be isolated in high purity and large numbers and under special culture conditions differentiated into macrophages for adoptive transfer. Once activated ex vivo, these cells display very high antibody dependent and independent specific cytotoxicity for tumour cells, are capable of phagocytosis of cancer cells and, as antigen presenting, cells are able to involve CTL in the anticancer response. As the understanding of this activation to cytotoxicity is only recent, the present paper first provides a literature review of the main points in the field. Our own results are then discussed in relation to the development of a clinical protocol for adoptive transfer of MAK (macrophage activated killer) cells, a therapeutic strategy having a pivotal role in the immunosurveillance of cancer.

Cell- and Tissue-Based Therapy↗

[Cancer immunotherapy by murine bladder cancer cells transfected with mouse interferon-gamma gene].

We established constitutively an interferon-gamma (IFN-gamma) producing cell line (MBT2/gamma) from a mouse bladder cancer cell line (MBT2) by retroviral transfer of a mouse IFN-gamma cDNA. Although the in vitro cell growth of these cells was unaffected by the IFN-gamma production, their subcutaneous tumor growth in syngeneic C3H/He mice was different; MBT2/gamma tumor growth was more strongly suppressed (3/20) than that of MBT2 (10/10). MBT2/gamma tumor growth was observed in nude mice (6/6). The mice immunized with MBT2/gamma were resistant to tumor growth of the parental cells (7/9; 77%), but permitted the growth of another kind of C3H/He tumor line. These findings indicate that the reduced tumorigenicity of the IFN-gamma producing line was due to the augmented specific antitumor immunity, probably as a result of the immunomodulatory effects of the IFN-gamma derived from the tumor.

Animals↗

Addressing current challenges in cancer immunotherapy with mathematical and computational modelling.

The goal of cancer immunotherapy is to boost a patient's immune response to a tumour. Yet, the design of an effective immunotherapy is complicated by various factors, including a potentially immunosuppressive tumour microenvironment, immune-modulating effects of conventional treatments and therapy-related toxicities. These complexities can be incorporated into mathematical and computational models of cancer immunotherapy that can then be used to aid in rational therapy design. In this review, we survey modelling approaches under the umbrella of the major challenges facing immunotherapy development, which encompass tumour classification, optimal treatment scheduling and combination therapy design. Although overlapping, each challenge has presented unique opportunities for modellers to make contributions using analytical and numerical analysis of model outcomes, as well as optimization algorithms. We discuss several examples of models that have grown in complexity as more biological information has become available, showcasing how model development is a dynamic process interlinked with the rapid advances in tumour-immune biology. We conclude the review with recommendations for modellers both with respect to methodology and biological direction that might help keep modellers at the forefront of cancer immunotherapy development.

Computer Simulation↗

Cancer immunotherapy: insights from transgenic animal models.

A wide range of strategies in cancer immunotherapy has been developed in the last decade, some of which are currently being used in clinical settings. The development of these immunotherapeutical strategies has been facilitated by the generation of relevant transgenic animal models. Since the different strategies in experimental immunotherapy of cancer each aim to activate different immune system components, a variety of transgenic animals have been generated either expressing tumor associated, HLA, oncogenic or immune effector cell molecule proteins. This review aims to discuss the existing transgenic mouse models generated to study and develop cancer immunotherapy strategies and the variable results obtained. The potential of the various transgenic animal models regarding the development of anti-cancer immunotherapeutical strategies is evaluated.

Animals↗

CpG DNA and cancer immunotherapy: orchestrating the antitumor immune response.

PURPOSE OF REVIEW: Cancer treatment is entering an era of targeted approaches. One such approach is use of the immune system to recognize and eliminate malignant cells. Synthetic CpG oligonucleotides (CpG DNA) are a relatively new class of agents that have the ability to stimulate a potent, orchestrated tumor-specific immune response. This review provides an overview of the immunologic effects of CpG DNA and summarizes the results of preclinical investigations that have led to ongoing development of CpG DNA as a component of clinical cancer immunotherapy. RECENT FINDINGS: New studies demonstrate that at least three classes of CpG DNA sequences exist, each with different physical characteristics and biologic effects. Preliminary studies in several animal models of cancer suggest that CpG DNA have the ability to induce tumor regression by activating innate immunity, enhancing antibody dependent cellular cytotoxicity, and serving as potent vaccine adjuvants that elicit a specific, protective immune response. SUMMARY: Animal models suggest that CpG DNA may have many uses in cancer immunotherapy. Early clinical trials suggest that CpG DNA can be administered safely to humans, and studies are ongoing to understand how these agents may play a role in cancer immunotherapy.

Adjuvants, Immunologic↗

Problems in the investigational study and clinical use of cancer immunotherapy.

The last decade has witnessed a veritable explosion in the investigational study and clinical use of immunotherapy for the treatment of cancer. Although this is an exciting development, the promise of cancer immunotherapy has not yet been fulfilled. Why is there an apparent discrepancy between the theory of cancer immunotherapy and the actual results from clinical studies? Michael Osband and Susan Ross suggest that there are several basic problems with the clinical study and therapeutic use of immunotherapy that must be overcome before it can be considered a viable treatment for a broad range of tumors. The purpose of this article is to describe some of the more important of these problems.

Adjuvants, Immunologic↗

Which immunological parameters are clinically essential to monitor IL-2 cancer immunotherapy?

The evaluation of the immunobiological changes occuring during IL-2 cancer immunotherapy is not only important to correlate them with the clinical response or to understand the immune mechanism involved in tumor growth control, but also to predict the efficacy of treatment itself. As far as the immune status of patients prior to therapy is concerned, the evidence of the activation of the inflammatory response correlates with resistance to IL-2. Therefore, the evidence of abnormally high pretreatment values of inflammatory response markers, including ESR, CRP, neopterin and SIL-2R, may predict a lack of IL-2 efficacy. In contrast, changes in inflammatory parameters during IL-2 administration have no prognostic significance. The evidence of elevated pretreatment levels of the immunosuppressive cytokine IL-10 has also an unfavourable prognostic significance. At the other side, the evidence of a marked increase in hemopoietic cells involved in tumor cell destruction, such as lymphocytes and eosinophils, as well as in blood levels of antitumor cytokines, such as IL-12, correlates with efficacy of IL-2 cancer immunotherapy. A better definition of the prognostic significance of immunoinflammatory markers will allow us to manipulate and improve host biological response during cancer immunotherapy with IL-2.

Blood Sedimentation↗

Dendritic cell-based cancer immunotherapy.

The development of effective cancer vaccines depends heavily on the ability to deliver target antigens to generate an immune response. Dendritic cells are the most potent antigen-processing cells, capable of sensitizing T cells to new and recall antigens. Dendritic cells express high levels of major histocompatibility complex class I and II antigens, which are crucial to cancer immunotherapy, as well as a variety of important immunomodulatory proteins, adhesins, and a potent cytokine. Dendritic cells must undergo activation to induce an immune response, and this can be achieved through the use of certain carrier proteins, adjuvants, cytokines, or genetically engineered viruses. Dendritic cells are scattered throughout many tissues of the body, as well as bone marrow and peripheral blood. Most studies have used dendritic cells from peripheral blood; however, these cells are not prevalent in peripheral blood mononuclear cells. The cytokine, granulocyte-macrophage colony-stimulating factor, has been found to induce the maturation and enhance the viability of dendritic cells isolated from peripheral blood. Numerous clinical trials of antigen-pulsed dendritic cells have been conducted in various types of cancer, including non-Hodgkin lymphoma, multiple myeloma, prostate cancer, malignant melanoma, colorectal cancer, and non-small cell lung cancer. These studies show that antigen-loaded dendritic cell vaccinations are safe and promising in the treatment of cancer. This review discusses the use of dendritic cells in immunotherapy and some of the clinical trials that have been conducted.

Cancer Vaccines↗

Cancer immunotherapy 2005: Mainz, Germany, 12-13 May 2005.

Cancer Immunotherapy 2005 was the third international meeting organized by the Association for Immunotherapy of Cancer (AIC). About 200 participants were attracted by the excellent scientific program that consisted of overview lectures from 25 international speakers in the plenary auditorium and four guided poster sessions during both days of the meeting. The first day of the symposium mainly focused on experience with, and new perspectives in, antibody therapy. On the second day of the meeting, organized as a joint conference together with the Combined Research Grant "Mechanisms of Tumor Defense and Therapeutic Intervention" funded by the German Research Council, the participants had the chance to gain deeper insights into the principles of antigen processing and the regulation of immune responses. Further topics that were discussed mainly in the poster sessions and in the special lecture given by M. Nishimura (Chicago, USA), were "cellular therapies" and "vaccination against cancer". The lectures selected for this report aim to provide an overview of the complete scientific program and give an impression of the lively atmosphere that could be felt from the first until the last session of CIMT 2005.

Antibodies, Monoclonal↗

Cripto as a target for cancer immunotherapy.

One of the recent, significant advances in cancer immunotherapy is the identification of molecules as targets which regulate cell growth by induction of proliferation and survival signalling pathways. Among them, epidermal growth factor receptor and Her2 have been effectively targeted by monoclonal antibodies. Currently, the treatment of cancer has limitations and most cancer deaths result from the local invasion and distant metastasis of tumour cells. An important insight for the understanding of tumour invasion and metastasis came from the recent discovery that the phenotypic changes of increased motility and invasiveness of cancer cells are reminiscent of the epithelial-mesenchymal transition (EMT) that occurs during embryonic development. The human Cripto, a member of the epidermal growth factor-Cripto, Frl1, and Cryptic (EGF-CFC) protein family and a signalling protein during early embryonic development, plays an important role in cancers. Cripto is attached to the cell membrane through a glycosyl-phosphatidylinositol motif, and is upregulated in a wide range of epithelial cancers. In this paper the authors review the role of Cripto expression in tumourigenesis and in EMT to promote tumour invasion, with emphasis that the unique EGF-like region of Cripto plays a critical role in Cripto signalling-mediated tumour growth and EMT. Therefore, the region should be regarded as a therapeutic point for interruption of the oncogenic and metastatic potential of Cripto for cancer immunotherapy.

Amino Acid Sequence↗