The immune system--is it relevant to cancer development, progression and treatment?

Advances in the study of tertiary lymphoid structures in the immunotherapy of breast cancer

Breast cancer, as one of the most common malignancies in women, exhibits complex and heterogeneous pathological characteristics across different subtypes. Triple-negative breast cancer (TNBC) and HER2-positive breast cancer are two common and highly invasive subtypes within breast cancer. The stability of the breast microbiota is closely intertwined with the immune environment, and immunotherapy is a common approach for treating breast cancer.Tertiary lymphoid structures (TLSs), recently discovered immune cell aggregates surrounding breast cancer, resemble secondary lymphoid organs (SLOs) and are associated with the prognosis and survival of some breast cancer patients, offering new avenues for immunotherapy. Machine learning, as a form of artificial intelligence, has increasingly been used for detecting biomarkers and constructing tumor prognosis models. This article systematically reviews the latest research progress on TLSs in breast cancer and the application of machine learning in the detection of TLSs and the study of breast cancer prognosis. The insights provided contribute valuable perspectives for further exploring the biological differences among different subtypes of breast cancer and formulating personalized treatment strategies.

Prognostic value of diffuse reduction of spleen density on postoperative survival of pancreatic ductal adenocarcinoma: A retrospective study

PURPOSE

It is difficult to predict the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC) before radical operation. The purpose of this study was to explore the connection between the diffuse reduction of spleen density on computed tomography (DROSD) and the postoperative prognosis of patients with PDAC.

PATIENTS AND METHODS

A total of 160 patients with PDAC who underwent radical surgery in the First Affiliated Hospital of Wenzhou Medical University were enrolled. Cox regression analysis was used to cast the overall survival (OS) and evaluate the prognostic factors. Nomogram was used to forecast the possibility of 1-year, 3-year, and 5-year OS. The prediction accuracy and clinical net benefit are performed by concordance index (C-index), calibration curve, time-dependent receiver operating characteristics (tdROC), and decision curve analysis.

RESULTS

In multivariable Cox analysis, DROSD is independently related to OS. Advanced age, TNM stage, neutrophil/lymphocyte ratio, and severe complications were also independent prognostic factors. The calibration curves of nomogram showed optimal agreement between prediction and observation. The C-index of nomogram is 0.662 (95%CI, 0.606-0.754). The area under tdROC curve for a 3-year OS of nomogram is 0.770.

CONCLUSION

DROSD is an independent risk factor for an OS of PDAC. We developed a nomogram that combined imaging features, clinicopathological factors, and systemic inflammatory response to provide a personalized risk assessment for patients with PDAC.

Melatonin: a modulator in metabolic rewiring in T-cell malignancies

Melatonin, (N-acetyl-5-methoxytryptamine) an indoleamine exerts multifaced effects and regulates numerous cellular pathways and molecular targets associated with circadian rhythm, immune modulation, and seasonal reproduction including metabolic rewiring during T cell malignancy. T-cell malignancies encompass a group of hematological cancers characterized by the uncontrolled growth and proliferation of malignant T-cells. These cancer cells exhibit a distinct metabolic adaptation, a hallmark of cancer in general, as they rewire their metabolic pathways to meet the heightened energy requirements and biosynthesis necessary for malignancies is the Warburg effect, characterized by a shift towards glycolysis, even when oxygen is available. In addition, T-cell malignancies cause metabolic shift by inhibiting the enzyme pyruvate Dehydrogenase Kinase (PDK) which in turn results in increased acetyl CoA enzyme production and cellular glycolytic activity. Further, melatonin plays a modulatory role in the expression of essential transporters (Glut1, Glut2) responsible for nutrient uptake and metabolic rewiring, such as glucose and amino acid transporters in T-cells. This modulation significantly impacts the metabolic profile of T-cells, consequently affecting their differentiation. Furthermore, melatonin has been found to regulate the expression of critical signaling molecules involved in T-cell activations, such as CD38, and CD69. These molecules are integral to T-cell adhesion, signaling, and activation. This review aims to provide insights into the mechanism of melatonin's anticancer properties concerning metabolic rewiring during T-cell malignancy. The present review encompasses the involvement of oncogenic factors, the tumor microenvironment and metabolic alteration, hallmarks, metabolic reprogramming, and the anti-oncogenic/oncostatic impact of melatonin on various cancer cells.

The Programmed Cell Death Ligand 1 and Lipocalin 2 Expressions in Primary Breast Cancer and Their Associations with Molecular Subtypes and Prognostic Factors

Purpose

Breast cancers exhibit molecular heterogeneity, leading to diverse clinical outcomes and therapeutic responses. Immune checkpoint inhibitors targeting PD-L1 have shown promise in various malignancies, including breast cancer. Lipocalin 2 (LCN2) has also been associated with tumor aggressiveness and prognostic potential in breast cancers. However, the expression of PD-L1 and LCN2 in breast cancer subtypes and their prognostic implications remains poorly investigated.

Methods

A retrospective analysis of 89 primary breast cancer cases was conducted to assess PD-L1 and LCN2 expressions using immunohistochemistry. Cases were classified into four different molecular subtypes based on ER, PR, HER2, and Ki-67 status. Associations between PD-L1 and LCN2 expressions and various prognostic factors were examined.

Results

Although low expression of LCN2 (Allred score of <3) was observed even in normal breast tissue, LCN2 expression with increasing Allred score (≥3) positively correlated with the histological grade, high Ki-67 proliferation index, and ER/PR negativity. Significant elevations of LCN2 and PD-L1 expressions were observed in triple-negative and HER2-positive breast cancers.

Conclusion

The results of the study highlight the association of LCN2 with known prognostic factors and molecular subtypes. To identify potential immunotherapy recipients, it would be useful to evaluate LCN2 as well as PD-L1 immune targets in different subgroups of breast cancer patients. Further studies with larger patient numbers are warranted to validate these observations and establish standardized scoring criteria for LCN2 expression assessment.

Immune Checkpoint Inhibitors and Novel Immunotherapy Approaches for Breast Cancer

PURPOSE OF REVIEW

To critically review the existing evidence on immune checkpoint inhibitors (ICIs) in early-stage and metastatic breast cancer and discuss emerging strategies in the different breast cancer subtypes.

RECENT FINDINGS

Immunotherapy has become one of the major milestones in contemporary oncology, revolutionizing the treatment of multiple solid tumors. ICI agents combined with chemotherapy have demonstrated significant efficacy in both early-stage and metastatic triple-negative breast cancer. However, only a subgroup of patients responds to those agents and some associated toxicities, although infrequent, can be life-disabling. Emerging data from immunotherapy studies in advanced hormone receptor-positive (HR +) breast cancer as well as HER2-positive disease are arising with mixed results. Although breast cancer has not classically been considered a hot tumor, ICIs have proven to be effective in a subset of breast cancer patients. However, much remains to be learned, and the identification of new biomarkers beyond PD-L1 expression is essential not only to improve the efficacy of ICI but also to identify patients who can avoid them, together with their toxicities and costs.

Thyroid Cancer and Pesticide Use in a Central California Agricultural Area: A Case Control Study

OBJECTIVE

To examine environmental factors that influence risk of thyroid cancer.

METHODS

We performed a case-control study utilizing thyroid cancer cases from the California Cancer Registry (1999-2012) and controls sampled in a population-based manner. Study participants were included if they were diagnosed with thyroid cancer, lived in the study area at their time of diagnosis, and were ≥35 years of age. Controls were recruited from the same area and eligible to participate if they were ≥35 years of age and had been living in California for at least 5 years prior to the interview. We examined residential exposure to 29 agricultural use pesticides, known to cause DNA damage in vitro or are known endocrine disruptors. We employed a validated geographic information system-based system to generate exposure estimates for each participant.

RESULTS

Our sample included 2067 cases and 1003 controls. In single pollutant models and within a 20-year exposure period, 10 out of 29 selected pesticides were associated with thyroid cancer, including several of the most applied pesticides in the United States such as paraquat dichloride [odds ratio (OR): 1.46 (95% CI: 1.23, 1.73)], glyphosate [OR: 1.33 (95% CI: 1.12, 1.58)], and oxyfluorfen [OR: 1.21 (95% CI: 1.02, 1.43)]. Risk of thyroid cancer increased proportionately to the total number of pesticides subjects were exposed to 20 years before diagnosis or interview. In all models, paraquat dichloride was associated with thyroid cancer.

CONCLUSIONS

Our study provides first evidence in support of the hypothesis that residential pesticide exposure from agricultural applications is associated with an increased risk of thyroid cancer.

Human Variation in DNA Repair, Immune Function, and Cancer Risk

DNA damage constantly threatens genome integrity, and DNA repair deficiency is associated with increased cancer risk. An intuitive and widely accepted explanation for this relationship is that unrepaired DNA damage leads to carcinogenesis due to the accumulation of mutations in somatic cells. But DNA repair also plays key roles in the function of immune cells, and immunodeficiency is an important risk factor for many cancers. Thus, it is possible that emerging links between inter-individual variation in DNA repair capacity and cancer risk are driven, at least in part, by variation in immune function, but this idea is underexplored. In this review we present an overview of the current understanding of the links between cancer risk and both inter-individual variation in DNA repair capacity and inter-individual variation in immune function. We discuss factors that play a role in both types of variability, including age, lifestyle, and environmental exposures. In conclusion, we propose a research paradigm that incorporates functional studies of both genome integrity and the immune system to predict cancer risk and lay the groundwork for personalized prevention.

The role of cytokines in the evolution of cancer: IFN-γ paradigm

The evolution of malignant cells implies an increase in oncogenic fitness of cells which arises in active and reciprocal interaction with the tumor microenvironment. The mechanisms facilitating the adaptive evolution of cancer cells involve clonal selection of cancer cells, in a direction of increased adaptive potential under the selective pressure of host defensive strategies. Once reached, this potential could go the other way, changing the same evolutionary force in the tumor microenvironment which influenced its emergence and favoring cancer progression. The immunological system as a part of host defensive mechanisms could be an effective modulator of cancer evolution/progression since it is also a major source of cellular intermediators, such as cytokines. The exemplar of IFN-γ actions during cancer evolution could help the revealing of these mutual interactions and enable better insight into the complex nature of cancer disease, leading to a new approach to treatment strategies.

Carriage of HLA-DRB1*11 and 1*12 alleles and risk factors in patients with breast cancer in Burkina Faso

Several factors contribute to the development of breast cancer, including the immune system. This study is aimed to characterize the carriage of human leukocyte antigen (HLA)-DRB1*11 and 1*12 alleles in patients with breast cancer. This case-control study consisted of 96 histologically diagnosed breast cancer cases and 102 controls (cases without breast abnormalities). A multiplex polymerase chain reaction (PCR) was used to characterize the carriage of HLA-DRB1*11 and 1*12 alleles. The HLA-DRB1*11 allele was present in 26.59% of cases and 22.55% of controls. The HLA-DRB1*12 allele was present in 56.63% of cases and 55.88% of controls. This study found no direct association between the carriage of the HLA-DRB1*11 and HLA-DRB1*12 alleles and the occurrence of breast cancer. In addition, the deletion of the HLA-DRB1*11 allele is associated (beneficial effect) with obesity/overweight (OR = 0.13; 95% CI [0.01-1.14]; and p = 0.03) which is a risk for breast cancer. No direct association was found between the carriage of HLA-DRB1*11 and 1*12 alleles and breast cancer risk. However, further investigation of other HLA alleles involved in the occurrence of breast cancer may provide more information.

Step-by-Step Immune Activation for Suicide Gene Therapy Reinforcement

Gene-directed enzyme prodrug gene therapy (GDEPT) theoretically represents a useful method to carry out chemotherapy for cancer with minimal side effects through the formation of a chemotherapeutic agent inside cancer cells. However, despite great efforts, promising preliminary results, and a long period of time (over 25 years) since the first mention of this method, GDEPT has not yet reached the clinic. There is a growing consensus that optimal cancer therapies should generate robust tumor-specific immune responses. The advent of checkpoint immunotherapy has yielded new highly promising avenues of study in cancer therapy. For such therapy, it seems reasonable to use combinations of different immunomodulators alongside traditional methods, such as chemotherapy and radiotherapy, as well as GDEPT. In this review, we focused on non-viral gene immunotherapy systems combining the intratumoral production of toxins diffused by GDEPT and immunomodulatory molecules. Special attention was paid to the applications and mechanisms of action of the granulocyte-macrophage colony-stimulating factor (GM–CSF), a cytokine that is widely used but shows contradictory effects. Another method to enhance the formation of stable immune responses in a tumor, the use of danger signals, is also discussed. The process of dying from GDEPT cancer cells initiates danger signaling by releasing damage-associated molecular patterns (DAMPs) that exert immature dendritic cells by increasing antigen uptake, maturation, and antigen presentation to cytotoxic T-lymphocytes. We hypothesized that the combined action of this danger signal and GM–CSF issued from the same dying cancer cell within a limited space would focus on a limited pool of immature dendritic cells, thus acting synergistically and enhancing their maturation and cytotoxic T-lymphocyte attraction potential. We also discuss the problem of enhancing the cancer specificity of the combined GDEPT–GM–CSF–danger signal system by means of artificial cancer specific promoters or a modified delivery system.

Profiles of immune infiltration and its relevance to survival outcome in meningiomas

Tumor-infiltrating immune cells play a decisive part in prognosis and survival. Until now, previous researches have not made clear about the diversity of cell types involved in the immune response. The objective of this work was to confirm the composition of tumor-infiltrating immune cells and their correlation with prognosis in meningiomas based on a metagene approach (known as CIBERSORT) and online databases. A total of 22 tumor-infiltrating immune cells were detected to determine the relationship between the immune infiltration pattern and survival. The proportion of M2 macrophages was more abundant in 68 samples, reaching more than 36%. Univariate Cox regression analysis displayed that the proportion of dendritic cells was obviously related to prognosis. Hierarchical clustering analysis identified two clusters by the method of within sum of squares errors, which exhibited different infiltrating immune cell composition and survival. To summarize, our results indicated that proportions of tumor-infiltrating immune cells as well as cluster patterns were associated with the prognosis, which offered clinical significance for research of meningiomas.

The effect of Tai Chi practice on immunological function in cancer survivors: A protocol for systematic review

BACKGROUND

Tai Chi has been reported to be potentially effective for health and well-being of cancer survivors. It is worth to assess the effectiveness and safety of Tai Chi on immunological function in people with cancer.

METHODS

All relevant randomized controlled trials (RCT) will be reviewed on Tai Chi for immunological function in cancer survivors. Literature searching will be conducted until March 9, 2019 from major English and Chinese databases: Cochrane Library, Excerpta Medica Database (EMBASE), PubMed, CINAHL, Sprotdicus, American Association for Cancer Research Journals, Sino-Med database, China National Knowledge Infrastructure, Chinese Science and Technique Journals Database, and Wanfang Data Chinese database. Two authors will conduct data selection and extraction independently. Quality assessment will be conducted using the risk of bias tool recommended by the Cochrane Collaboration. We will conduct data analysis using Cochrane's RevMan software (V.5.3). Forest plots and summary of findings tables will illustrate the results from a meta-analysis if sufficient studies with the same outcomes are identified. Funnel plots will be developed to evaluate reporting bias.

RESULTS

This review will summarize the evidence on Tai Chi for immunological function in cancer survivors.

CONCLUSIONS

We hope that the results of this study will provide significant evidence to assess the value Tai Chi practice on immunological function in cancer survivors.

ETHICS AND DISSEMINATION

Ethics approval is not required as this study will not involve patients. The results of this study will be submitted to a peer-reviewed journal for publication.

Anticancer Activity of Solvent Extracts of Hexogonia glabra against Cervical Cancer Cell Lines

Objective:

In this study, we aimed to harness some solvent extracts of one wild mushroom Hexagonia glabra and test their anti-cancer activity against cervical human cell lines, namelyHeLa, SiHa, and CaSki.

Methods:

It includes cell morphological study by microscope, nuclear morphology by DAPI staining under fluorescence microscopy, apoptosis assay by fluorescence technique, anti-proliferation by MTT assay and expression of apoptotic and anti-apoptotic genes by Western blotting and cell cycle analysis was done.

Results:

The selected cervical cancer cells were treated separately with 150 µg/mL of three extracts, namely of ethanolic (EE), ethyl acetate (EAE), and water extract (WE) and exhibited features like round, shrink and dead. All extracts caused apoptosis in cell lines and EE had the highest effect in this regard. The percentages of apoptotic cells in HeLa, SiHa and CaSki, at the same concentration of EE were 79.23, 75.42, and 76.36% respectively. Cytotoxicity assay showed that all three extracts (50 – 250 μg/mL) were potent for inhibition of cell growth of three cell lines and again EE had the highest effect. The percentages of cell growth inhibition in HeLa, SiHa, and CaSki cells treated with EE at 24 h at 50 µg/mL were 45.79±4.11, 41.66±4.03, and 36.72±2.67, while they were 74.23±7.45, 62.31±5.97, and 54.23±5.04 at 150 µg/mL concentration. At 250 µg/mL concentration, the percentages of cell growth inhibition were 94.25 ±8.11, 90.02 ±8.67, and 85.43±6.21, respectively. The expression of apoptotic gene (Caspase 3, 9) and tumor guard gene (p53), as their proteins in Western blotting increased . However, anti-apoptotic BcL2 gene of all cell lines was decreased following treatment with extracts. In addition, the cell cycle analysis (CaSki cell) showed that treatment (EE) arrested at G2/M check point cell cycle.

Conclusion:

All extracts of this mushroom were active in arresting growth of three cell lines and EE had the highest effect, indicating that this mushroom can be a valuable source of anticancer agents.

Diffuse Reduction of Spleen Density Is an Independent Predictor of Post-Operative Outcomes After Curative Gastrectomy in Gastric Cancer: A Multi-Center Study

Objectives: The present study aimed to explore the association between spleen density and post-operative outcomes of patients after curative gastrectomy.

Methods: From June 2014 to December 2015, we conducted a retrospective study to analyze pertinent clinical data from gastric cancer patients who underwent gastrectomy at the First and the Second Affiliated Hospital of Wenzhou Medical University. Spleen density was determined via computed tomography scans. Univariate and multivariate analyses were performed to determine the risk factors associated with post-operative outcomes after gastric cancer surgery.

Results: Three hundred and ninety five patients were included, of whom 98 (24.8%) were defined as having a diffuse reduction of spleen density based on diagnostic cutoff values (spleen density ≤43.89 HU). Multivariate analysis revealed diffuse reduction of spleen density as an independent risk factor for post-operative complications and long-term overall survival.

Conclusions: Spleen density can predict severe postoperative complications and long-term overall survival in gastric cancer patients. As an imaging evaluation method, spleen density is a novel tool can be used in clinical as a prognostic predictor for patients with gastric cancer.

The significance of gene mutations across eight major cancer types

Mutations occur spontaneously, which can be induced by either chemicals (e.g. benzene) or biological factors (e.g. virus). Not all mutations cause noticeable changes in cellular functions. However, mutation in key cellular genes leads to developmental disorders. It is one of the main ways in which proto-oncogenes can be changed into their oncogenic state. The progressive accumulation of multiple mutations throughout life leads to cancer. In the past few decades, extensive research on cancer biology has discovered many genes and pathways having role in cancer development. In this review, we tried to summarize the current knowledge of mutational effect on different cancer types and its consequences in brief for future reference and guidance of researchers in cancer biology.

FEATURES OF NEUTROPHIL CHEMILUMINESCENCE IN THE PATIENTS WITH ADVANCED RECTAL CANCER

Colorectal cancer is one of the most common malignant diseases in Russia worldwide making up 5-6% of all human malignant tumors. Neutrophilic granulocytes are actively involved in development of antitumor response. A key role in tumor regression is assigned to active forms of oxygen produced by neutrophils. In connection with these pre-requisites, our goal was to study functional characteristics of spontaneous and induced chemiluminescent activity of neutrophil granulocytes in patients with rectal cancer before starting pathogenetic therapy and in subsequent dynamics. The paper presents some laboratory results, i.e., functional indices of neutrophilic granulocytes’ activity in 36 patients with rectal cancer being at different stages of oncological process. The control group consisted of 112 practically healthy volunteers, comparable in sex and age to the group of patients under study. To perform the study venous blood was taken from patients to vacuum test tubes with lithium heparin in the morning time before surgical treatment, and on day 7 after the surgical intervention. Evaluation of spontaneous and induced chemiluminescence was performed for 90 minutes in a 36-channel “CL 3606” chemiluminescence analyzer (Russia). The following characteristics were determined: time of the curve transition to maximal chemiluminescence intensity (Tmax), maximal value of chemiluminescence intensity (Imax), integral area under the chemiluminescence curve (S). Luminol was used as the chemiluminescence enhancer. Opsonized zymosan was used to induce the respiratory explosion. Chemiluminescence amplification induced by opsonized zymosan was evaluated by the ratio of induced-tospontaneous chemiluminescence (Sind/spont) designated as an activation index.

Analysis of chemiluminescence activity in neutrophilic granulocytes showed a significant increase in spontaneous chemiluminescence activity at the stages III and IV of the disease. The production of active oxygen forms induced in neutrophilic granulocytes by opsonized zymosan increased in all the study groups, relative to control parameters. The area under the curves of spontaneous and induced chemiluminescence in patients with colorectal cancer at all stages of the oncological process is less, as compared to the control group, which, despite high indices of maximal chemiluminescence activity, may indicate insufficient total production of reactive oxygen species. The time-to-peak values of the chemiluminescence curves in patients with rectal cancer at all stages of the disease did not show statistically significant differences from the control group.

Imaging response assessment of immunotherapy in patients with renal cell and urothelial carcinoma

PURPOSE OF REVIEW

Recent advances in anticancer immunotherapy have revolutionized the treatment of metastatic renal cell (RCC) and urothelial carcinoma. In this review, we discuss the mechanisms of action of these new therapeutic approaches, explicate the common adverse events, and highlight different imaging-based response criteria.

RECENT FINDINGS

The recent introduction of immune-checkpoint inhibitors led to substantial advances in therapy of metastatic RCC and urothelial carcinoma. Because of the distinct effector mechanisms of these new substances, atypical response patterns such as transient enlargements of tumor lesions, appearance of new lesions after therapy, no measurable decrease in tumor size, or delayed responses are observed in medical imaging studies. This indicates that the established imaging-based response assessment according to the Response Evaluation Criteria in Solid Tumors (RECIST) guidelines has shortcomings to comprehensively evaluate treatment effects.

SUMMARY

While monitoring response to immunotherapy still relies on RECIST criteria, immune-related response criteria have been established to better address the imaging changes occurring under immunotherapy. Further studies with long-term follow-up are needed to properly identify and predict response after treatment beyond progression. Because of the expanding clinical use of immune checkpoint inhibitors, radiologists, urologist, and oncologists should be familiar with common imaging findings under this respective therapy.

(Mesenchymal) Stem Cell-Based Therapy in Cisplatin-Induced Acute Kidney Injury Animal Model: Risk of Immunogenicity and Tumorigenicity

Pathogenesis of AKI is complex and involves both local events in the kidney as well as systemic effects in the body that are interconnected and interdependent. Despite intensive investigations there is still no pharmacological agent that could provide complete protection against cisplatin nephrotoxicity. In the last decade mesenchymal stem cells (MSCs) have been proposed as a potentially useful therapeutic strategy in various diseases, including acute kidney injury. Although MSCs have potent immunosuppressive properties, animal studies also suggest that transplanted MSCs may elicit immune response. Interestingly, tumorigenicity of transplanted MSCs in animal studies has been rarely studied. Since the risk of tumorigenicity of particular therapy as well as the immune response to solid or cell grafts is a major issue in clinical trials, the aim of the present paper is to critically summarize the results of MSC transplantation on animal models of AKI, particularly cisplatin-induced animal models, and to expose results and main concerns about immunogenicity and tumorigenicity of transplanted MSCs, two important issues that need to be addressed in future studies.

Adaptive Resistance to Cancer Immunotherapy

Immunosuppressive mechanisms within the tumor microenvironment have emerged as a major impediment to cancer immunotherapy. While a broad range of secreted factors, receptors/ligands, and cell populations have been described that contribute to the immunosuppression, the involvement of these processes in immune evasion by tumors is typically considered to be an intrinsic property of the tumor. Evidence is now emerging that the processes underlying immune suppression within the tumor are, in fact, triggered by immune attack and reflect a dynamic interplay between the tumor and the host's immune system. The term adaptive resistance has been coined to describe the induction of immune suppressive pathways in the tumor following active attack on the tumor. Adaptive resistance is a scalable process where the magnitude of immune suppression matches the magnitude of the immune attack; the net balance between suppression and attack determines the durability of the anti-tumor response and tumor outcome. In this chapter, we will examine the data supporting adaptive resistance and the opposing roles of T cells in simultaneously promoting both anti-tumor immunity and immune suppression within the tumor microenvironment. The clinical implications of adaptive resistance in the design and application of immunotherapeutic strategies is also discussed.

Myeloid cell leukaemia 1 has a vital role in retinoic acid-mediated protection of Toll-like receptor 9-stimulated B cells from spontaneous and DNA damage-induced apoptosis

Vitamin A is an essential anti-infective agent with pleiotropic effects on cells of the immune system. The goal of the present study was to unravel the impact of the vitamin A metabolite retinoic acid (RA) on B-cell survival related both to normal B-cell homeostasis and to the detrimental effects imposed by DNA-damaging agents. By combining RA with Toll-like receptor 9 (TLR9) ligands, we show that RA prevents spontaneous, irradiation- and doxorubicin-induced apoptosis of human B cells in an RA receptor-dependent manner. RA-mediated survival involved up-regulation of the anti-apoptotic protein myeloid cell leukemia 1 (MCL1) at the transcriptional level, and knock down of MCL1 by small interfering RNA partially reversed the effects of RA. To ensure that the combination of TLR9-ligands and RA would not promote the survival of malignant B cells, the combined effects of stimulation with RA and TLR9 ligands was assessed on cells from patients with B-cell malignancies. In contrast to the effects on normal B cells, the combination of TLR9 stimulation and RA neither enhanced the MCL1 levels nor inhibited the death of malignant B cells challenged by DNA-damaging agents. Taken together, the present results reveal a vital role of MCL1 in RA-mediated survival of normal B cells. Moreover, the findings suggest that RA in combination with TLR9 ligands might be useful adjuvants in the treatment of B-cell malignancies by selectively protecting normal and not malignant B cells from DNA-damage-induced cell death.

Definitive chemoradiation alters the immunologic landscape and immune checkpoints in head and neck cancer

BACKGROUND

Preclinical and clinical studies suggest potential synergy between high dose per fraction focal radiation and immunotherapy. However, conventionally fractionated radiation regimens in combination with concurrent chemotherapy are more commonly administered to patients as definitive treatment and may have both immune-stimulating and -suppressive effects.

METHODS

We prospectively collected longitudinal samples from head and neck squamous cell carcinoma patients receiving definitive radiation therapy. We quantified changes in populations of circulating immune cells and chemokines CXCL9, 10, and 16. Analyses of humoral and cellular immune responses were conducted in select patients via proteomic analysis and T-cell receptor sequencing.

RESULTS

Treatment not only increased circulating CD-8+ T-effector cells, but also myeloid-derived suppressor cells, regulatory T cells, and checkpoint receptor-expressing T cells, particularly PD-1+ T cells. Significant decreases in CXCL10 and increases in CXLC16 were noted. Treatment also increased the percentage of unique and dominant TCR clones, and increased humoral responses as measured by proteomic array.

CONCLUSIONS

Our results suggest that fractionated chemoradiation leads to quantifiable effects in circulating immune mediators, including a balance of stimulatory and suppressive mechanisms. These results suggest future combinations with immune checkpoint blockade.

Evaluating biomarkers to model cancer risk post cosmic ray exposure

Robust predictive models are essential to manage the risk of radiation-induced carcinogenesis. Chronic exposure to cosmic rays in the context of the complex deep space environment may place astronauts at high cancer risk. To estimate this risk, it is critical to understand how radiation-induced cellular stress impacts cell fate decisions and how this in turn alters the risk of carcinogenesis. Exposure to the heavy ion component of cosmic rays triggers a multitude of cellular changes, depending on the rate of exposure, the type of damage incurred and individual susceptibility. Heterogeneity in dose, dose rate, radiation quality, energy and particle flux contribute to the complexity of risk assessment. To unravel the impact of each of these factors, it is critical to identify sensitive biomarkers that can serve as inputs for robust modeling of individual risk of cancer or other long-term health consequences of exposure. Limitations in sensitivity of biomarkers to dose and dose rate, and the complexity of longitudinal monitoring, are some of the factors that increase uncertainties in the output from risk prediction models. Here, we critically evaluate candidate early and late biomarkers of radiation exposure and discuss their usefulness in predicting cell fate decisions. Some of the biomarkers we have reviewed include complex clustered DNA damage, persistent DNA repair foci, reactive oxygen species, chromosome aberrations and inflammation. Other biomarkers discussed, often assayed for at longer points post exposure, include mutations, chromosome aberrations, reactive oxygen species and telomere length changes. We discuss the relationship of biomarkers to different potential cell fates, including proliferation, apoptosis, senescence, and loss of stemness, which can propagate genomic instability and alter tissue composition and the underlying mRNA signatures that contribute to cell fate decisions. Our goal is to highlight factors that are important in choosing biomarkers and to evaluate the potential for biomarkers to inform models of post exposure cancer risk. Because cellular stress response pathways to space radiation and environmental carcinogens share common nodes, biomarker-driven risk models may be broadly applicable for estimating risks for other carcinogens.

The Sweet Side of Immune Evasion: Role of Glycans in the Mechanisms of Cancer Progression

Glycans are part of the essential components of a cell. These compounds play a fundamental role in several physiopathological processes, including cell differentiation, adhesion, motility, signal transduction, host-pathogen interactions, tumor cell invasion, and metastasis development. Glycans are also able to exert control over the changes in tumor immunogenecity, interfering with tumor editing events and leading to immune-resistant cancer cells. The involvement of glycans in cancer progression is related to glycosylation alterations. Understanding such changes is, therefore, extremely useful to set the stage for their use as biomarkers, improving the diagnostics and therapeutic strategies. Herein, we discuss the basis of how modifications in glycosylation patterns may contribute to cancer genesis and progression as well as their importance in oncology field.

Potential for Improving Potency and Specificity of Reovirus Oncolysis with Next-Generation Reovirus Variants

Viruses that specifically replicate in tumor over normal cells offer promising cancer therapies. Oncolytic viruses (OV) not only kill the tumor cells directly; they also promote anti-tumor immunotherapeutic responses. Other major advantages of OVs are that they dose-escalate in tumors and can be genetically engineered to enhance potency and specificity. Unmodified wild type reovirus is a propitious OV currently in phase I–III clinical trials. This review summarizes modifications to reovirus that may improve potency and/or specificity during oncolysis. Classical genetics approaches have revealed reovirus variants with improved adaptation towards tumors or with enhanced ability to establish specific steps of virus replication and cell killing among transformed cells. The recent emergence of a reverse genetics system for reovirus has provided novel strategies to fine-tune reovirus proteins or introduce exogenous genes that could promote oncolytic activity. Over the next decade, these findings are likely to generate better-optimized second-generation reovirus vectors and improve the efficacy of oncolytic reotherapy.

The immune mechanisms of abscopal effect in radiation therapy

Radiation therapy (RT) is a cornerstone in oncologic management and is employed in various curative and palliative scenarios for local-regional control. RT is thought to locally control tumor cells by direct physical DNA damage or indirect insults from reactive oxygen species. Therapeutic effects apart from those observed at the treatment target, that is, abscopal effect, have been observed for several decades, though the underlying mechanisms regulating this phenomenon have been unclear. Accumulating evidence now suggests that the immune system is a major determinant in regulating the abscopal effect. It is now evident that RT may also enhance immunologic responses to tumors by creating an in situ vaccine by eliciting antigen release from dying tumor cells. Harnessing the specificity and dynamic nature of the immune system to target tumors in conjunction with RT is an emerging field with much promise. To optimize this approach, it is important to systematically evaluate the intricacies of the host immune system, the new generation of immunotherapeutics and the RT approach. Here we will discuss the current biologic mechanisms thought to regulate the RT-induced abscopal effect and how these may be translated to the clinical setting.

Myeloid-derived cells in tumors: effects of radiation

The discrepancy between the in vitro and in vivo response to radiation is readily explained by the fact that tumors do not exist independently of the host organism; cancer cells grow in the context of a complex microenvironment composed of stromal cells, vasculature, and elements of the immune system. As the antitumor effect of radiotherapy depends in part on the immune system, and myeloid-derived cells in the tumor microenvironment modulate the immune response to tumors, it follows that understanding the effect of radiation on myeloid cells in the tumor is likely to be essential for comprehending the antitumor effects of radiotherapy. In this review, we describe the phenotype and function of these myeloid-derived cells, and stress the complexity of studying this important cell compartment owing to its intrinsic plasticity. With regard to the response to radiation of myeloid cells in the tumor, evidence has emerged demonstrating that it is both model and dose dependent. Deciphering the effects of myeloid-derived cells in tumors, particularly in irradiated tumors, is key for attempting to pharmacologically modulate their actions in the clinic as part of cancer therapy.

The Association Between Chemoradiation-related Lymphopenia and Clinical Outcomes in Patients With Locally Advanced Pancreatic Adenocarcinoma

OBJECTIVES

Lymphopenia is a common consequence of chemoradiation therapy yet is seldom addressed clinically. This study was conducted to determine if patients with locally advanced pancreatic cancer (LAPC) treated with definitive chemoradiation develop significant lymphopenia and if this affects clinical outcomes.

METHODS

A retrospective analysis of patients with LAPC treated with chemoradiation at a single institution from 1997 to 2011 was performed. Total lymphocyte counts (TLCs) were recorded at baseline and then monthly during and after chemoradiation. The correlation between treatment-induced lymphopenia, established prognostic factors, and overall survival was analyzed using univariate Cox regression analysis. Important factors identified by univariate analysis were selected as covariates to construct a multivariate proportional hazards model for survival.

RESULTS

A total of 101 patients met eligibility criteria. TLCs were normal in 86% before chemoradiation. The mean reduction in TLC per patient was 50.6% (SD, 40.6%) 2 months after starting chemoradiation (P<0.00001), and 46% had TLC<500 cells/mm. Patients with TLC<500 cells/mm 2 months after starting chemoradiation had inferior median survival (8.7 vs. 13.3 mo, P=0.03) and PFS (4.9 vs. 9.0 mo, P=0.15). Multivariate analysis revealed TLC<500 cells/mm to be an independent predictor of inferior survival (HR=2.879, P=0.001) along with baseline serum albumin (HR=3.584, P=0.0002), BUN (HR=1.060, P=0.02), platelet count (HR=1.004, P=0.005), and radiation planning target volume (HR=1.003, P=0.0006).

CONCLUSIONS

Severe treatment-related lymphopenia occurs frequently after chemoradiation for LAPC and is an independent predictor of inferior survival.

Establishment of a heterotypic 3D culture system to evaluate the interaction of TREG lymphocytes and NK cells with breast cancer

Three-dimensional (3D) culture approaches to investigate breast tumour progression are yielding information more reminiscent of the in vivo microenvironment. We have established a 3D Matrigel system to determine the interactions of luminal phenotype MCF-7 cells and basal phenotype MDA-MB-231 cells with regulatory T lymphocytes and Natural Killer cells. Immune cells were isolated from peripheral blood using magnetic cell sorting and their phenotype validated using flow cytometry both before and after activation with IL-2 and phytohaemagglutinin. Following the establishment of the heterotypic culture system, tumour cells displayed morphologies and cell-cell associations distinct to that observed in 2D monolayer cultures, and associated with tissue remodelling and invasion processes. We found that the level of CCL4 secretion was influenced by breast cancer phenotype and immune stimulation. We further established that for RNA extraction, the use of proteinase K in conjunction with the Qiagen RNeasy Mini Kit and only off-column DNA digestion gave the best RNA yield, purity and integrity. We also investigated the efficacy of the culture system for immunolocalisation of the biomarkers oestrogen receptor-α and the glycoprotein mucin 1 in luminal phenotype breast cancer cells; and epidermal growth factor receptor in basal phenotype breast cancer cells, in formalin-fixed, paraffin-wax embedded cultures. The expression of these markers was shown to vary under immune mediation. We thus demonstrate the feasibility of using this co-culture system for downstream applications including cytokine analysis, immunolocalisation of tumour biomarkers on serial sections and RNA extraction in accordance with MIQE guidelines.

Dexamethasone enhances programmed cell death 1 (PD-1) expression during T cell activation: an insight into the optimum application of glucocorticoids in anti-cancer therapy

Background

Programmed cell death 1 (PD-1) is a key cell-surface receptor of CD28 superfamily that triggers inhibitory pathways to attenuate T-cell responses and promote T-cell tolerance. As a crucial role in tumor immunity, PD-1 has been a focus of studies in anti-cancer therapy. It has been approved that tumors could exploit PD-1-dependent immune suppression for immune evasion. Considering the wide use of glucocorticoids (GCs) in anti-cancer therapy and their immunosuppressive effects, we explored whether GCs could influence the expression of PD-1.

Results

In our study, we used dexamethasone (DEX) as a model glucocorticoid and demonstrated that DEX could enhance PD-1 expression in a dose-dependent manner. The effects were completely inhibited by the glucocorticoid receptor (GR) antagonist mifepristone (RU486), indicating that the effect of DEX on PD-1 is mediated through GR. We further found the sensitivity to DEX-induced upregulation of PD-1 expression had a significant difference between different T cell subsets, with memory T cells more susceptible to this effect. We also showed that DEX could suppress T cell functions via inhibition of cytokines production such as IL-2, IFN-γ, TNF-α and induction of apoptosis of T cells.

Conclusion

Our findings suggest a novel way by which DEX suppress the function of activated T lymphocytes by enhancing expression of PD-1 and provide an insight into the optimum clinical application of GCs.

Immune reconstitution from peripheral blood mononuclear cells inhibits lung carcinoma growth in NOD/SCID mice

Drug resistance and immune deficiency are important factors for the poor prognosis of lung carcinoma. The present study explored the possible protective effect of immune reconstitution from peripheral blood mononuclear cells (PBMCs) on multi-drug-resistant human lung carcinoma Am1010 cells in non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. The inoculated tumor fragments grew rapidly in the NOD/SCID mice. The growth was significantly inhibited by intraperitoneal injection of PBMCs. In the mice injected with PBMCs, numerous CD3⁺ and CD8⁺ cells, but less CD4⁺ cells, were found in spleen and tumor tissues. These data suggest that PBMC transplantation inhibits lung carcinoma progression via the reconstitution of the immune system, particularly of cytotoxic T lymphocytes.

Oncogene withdrawal engages the immune system to induce sustained cancer regression

The targeted inactivation of a single oncogene can induce dramatic tumor regression, suggesting that cancers are “oncogene addicted.” Tumor regression following oncogene inactivation has been thought to be a consequence of restoration of normal physiological programs that induce proliferative arrest, apoptosis, differentiation, and cellular senescence. However, recent observations illustrate that oncogene addiction is highly dependent upon the host immune cells. In particular, CD4⁺ helper T cells were shown to be essential to the mechanism by which MYC or BCR-ABL inactivation elicits “oncogene withdrawal.” Hence, immune mediators contribute in multiple ways to the pathogenesis, prevention, and treatment of cancer, including mechanisms of tumor initiation, progression, and surveillance, but also oncogene inactivation-mediated tumor regression. Data from both the bench and the bedside illustrates that the inactivation of a driver oncogene can induce activation of the immune system that appears to be essential for sustained tumor regression.

Nanoengineered strategies to optimize dendritic cells for gastrointestinal tumor immunotherapy: from biology to translational medicine

Nanomedicine may play an important role in improving the clinical efficacy of dendritic cell-based immunotherapy against GI tract malignancies. Dendritic cell-based vaccines have proven their effectiveness against different established GI tract tumors, yet their success is mainly hindered by the strong tumor-induced suppressive microenvironment. The sustained and targeted release of tumor antigens to dendritic cells using different nanoengineered approaches would be an efficient strategy to overcome established immune tolerance. Encapsulation would result in low diffusivity, restricted movement, effective crosspresentation and enhanced T-cell responses. These nanotherapy-based approaches will certainly help with the designing of clinically translatable dendritic cell-based therapeutic vaccines and facilitate the selective removal of residual disease in gastrointestinal cancer patients following standard treatments.

The Prognostic Role of the Neutrophil-to-Lymphocyte Ratio in Oropharyngeal Carcinoma Treated with Chemoradiotherapy

BACKGROUND

The aim of the study is to investigate the prognostic role of pre-treatment of markers of the systemic inflammatory response (neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and albumin) in patients with oropharyngeal carcinoma treated with chemoradiotherapy.

METHODS

A total of 251 patients with oropharyngeal squamous cell cancer treated with chemoradiotherapy between 2004 and 2010 were retrospectively identified. NLR, PLR, and albumin were recorded from baseline blood parameters. NLR threshold of >5 and PLR thresholds of ≤150, >150 and ≤300, and >300 were used for analysis.

RESULTS

Median follow-up was 46 months (range 9–98). The 3 year overall survival, local control, regional control, and distant control were 70%, 85%, 87%, and 87%, respectively. On multivariate analysis, locoregional control was associated with T stage (HR 3.3 (95% CI 1.5–6.9), P = 0.002) and NLR (HR 2.1 (95% CI 1.1–3.9), P = 0.023). Overall survival was associated with T stage (HR 2.47 (95% CI 1.45–4.2), P = 0.001) and grade (HR 0.61 (95% CI 0.38–0.99), P = 0.048). PLR and albumin were not significantly associated with disease outcomes or survival.

CONCLUSIONS

The NLR is an independent prognostic factor for locoregional control in oropharyngeal cancer treated with chemoradiotherapy.

An essential role for the immune system in the mechanism of tumor regression following targeted oncogene inactivation

Tumors are genetically complex and can have a multitude of mutations. Consequently, it is surprising that the suppression of a single oncogene can result in rapid and sustained tumor regression, illustrating the concept that cancers are often "oncogene addicted." The mechanism of oncogene addiction has been presumed to be largely cell autonomous as a consequence of the restoration of normal physiological programs that induce proliferative arrest, apoptosis, differentiation, and/or cellular senescence. Interestingly, it has recently become apparent that upon oncogene inactivation, the immune response is critical in mediating the phenotypic consequences of oncogene addiction. In particular, CD4(+) T cells have been suggested to be essential to the remodeling of the tumor microenvironment, including the shutdown of host angiogenesis and the induction of cellular senescence in the tumor. However, adaptive and innate immune cells are likely involved. Thus, the effectors of the immune system are involved not only in tumor initiation, tumor progression, and immunosurveillance, but also in the mechanism of tumor regression upon targeted oncogene inactivation. Hence, oncogene inactivation may be an effective therapeutic approach because it both reverses the neoplastic state within a cancer cell and reactivates the host immune response that remodels the tumor microenvironment.

A role for T-lymphocytes in human breast cancer and in canine mammary tumors

Chronic inflammation in the tumor microenvironment has a prominent role in carcinogenesis and benefits the proliferation and survival of malignant cells, promoting angiogenesis and metastasis. Mammary tumors are frequently infiltrated by a heterogeneous population of immune cells where T-lymphocytes have a great importance. Interestingly, similar inflammatory cell infiltrates, cytokine and chemokine expression in humans and canine mammary tumors were recently described. However, in both species, despite all the scientific evidences that appoint for a significant role of T-lymphocytes, a definitive conclusion concerning the effectiveness of T-cell dependent immune mechanisms has not been achieved yet. In the present review, we describe similarities between human breast cancer and canine mammary tumors regarding tumor T-lymphocyte infiltration, such as relationship of TILs and mammary tumors malignancy, association of ratio CD4+/ CD8+ T-cells with low survival rates, promotion of tumor progression by Th2 cells actions, and association of great amounts of Treg cells with poor prognostic factors. This apparent parallelism together with the fact that dogs develop spontaneous tumors in the context of a natural immune system highlight the dog as a possible useful biological model for studies in human breast cancer immunology.

Histologic and systemic prognosticators for local control and survival in margin-negative transoral laser microsurgery treated oral cavity squamous cell carcinoma

BACKGROUND

Appreciable local recurrence rates observed in patients with margin-negative, transoral laser microsurgery (TLM)-treated oral cavity squamous cell carcinoma (SCC) necessitate identification of new prognosticators for local control and survival. A histopathologic index (Brandwein-Gensler score [BGS]) and intrinsic/iatrogenic/chronic conditions causing immune compromise are investigated.

METHODS

From a prospectively assembled database of TLM-treated oral cavity SCC, specimens for 60 patients with a minimum of 2-years follow-up could undergo BGS assignment. Local control, disease-specific survival (DSS), and overall survival (OS) were study endpoints.

RESULTS

"Low-BGS" was recorded in 28 patients (47%) and "high-BGS" in 32 patients (53%), whereas immune compromise was observed in 18%. In multivariate analyses, immune compromise was the only predictor for local control. T classification and immune compromise were prognostic for DSS and OS. "High-BGS" was prognostic only for OS.

CONCLUSION

"High-BGS" was associated with recurrences but immune compromise was the most significant predictor of local control and survival in margin-negative, TLM-treated oral cavity SCC. Strategies that maintain/restore tumor-specific immune responses in immune compromised oral cavity SCC hosts need to be developed.

Genomic signatures of pregnancy-associated breast cancer epithelia and stroma and their regulation by estrogens and progesterone

Pregnancy-associated breast cancers (PABC) generally present at advanced stages and have a poor prognosis. The reasons are unclear but we hypothesized that the continuous high levels of estrogens and progesterone were involved. We have now carried out a detailed analysis of PABC compared to tumors of age-matched nonpregnant (non-PABC) women. Malignant epithelia and tumor-associated stroma of PABC and non-PABC were isolated by laser capture microdissection and gene expression profiled. Additionally, normal breast epithelia and stroma adjacent to the two tumor types were analyzed. Lastly, subsets of previously identified E- and P-regulated genes were defined in all tissues. We find that PABC signatures cluster with established breast cancer subtypes. Major hormone-regulated genes whose expression correlated with epithelia of PABC dealt with regulation of cell proliferation, metabolism, and tumor aggressiveness, including genes used to predict tumor recurrence. Compared to normal epithelia, a significant number of genes associated with cell cycle processes were enriched in PABC, many of which are hormone regulated. Thus, compared to normal epithelia, many of the genes that were differentially expressed in epithelia of PABC were distinct from those differentially expressed in non-PABC. With regard to the tumor microenvironment, immune-related genes were enriched in tumor-associated stroma of PABC. Compared to normal stroma, PABC-associated stroma overexpressed immune response genes, while genes involved in angiogenesis and extracellular matrix deposition were more commonly downregulated. This suggests that the heightened aggressiveness of PABC may involve a predisposition to metastasis through extracellular matrix degradation, plus angiogenesis independence. Moreover, genes encoding cell proliferative factors, signaling, immunomodulators and cell death, were hormone regulated in stroma. In sum, these analyses demonstrate complex patterns of enrichment and hormonal regulation of genes in PABC and suggest that it may have a distinct biological nature.

Analyses of T cell-mediated immune response to a human melanoma-associated antigen by the young and the elderly

Elderly cancer patients are often excluded from immune-based clinical trials and therapies based on the belief that they respond poorly to tumor antigens. Using melanoma as a model and melanoma related Mart-127-35 epitope specific T cell receptor (TCR) engineered T cells as a tool we compared the T cell responses from young and elderly to the Mart-127-35 epitope, ex vivo. We also compared the natural Treg (nTreg) activities and the expression of a number of genes associated with immune response by quantitative real-time reverse Transcription Polymerase Chain Reaction (qRTPCR) in formalin fixed primary melanomas, in situ. We detected a significant difference in CD8(+) T cell response to Flu antigen (influenza matrix peptide Flu MP58-66), but the responses of the two cohorts to melanoma antigen were comparable. nTreg activities in the elderly was significantly compromised. The qPCR analyses of tissues from elderly patients revealed lower levels of Fox-P3 expression but comparable levels of expression of IL-2, IFNγ, TNFα, IL-4, IL-10, IDO, and TGFβ. These findings indicate that elderly patients might be capable of responding to tumor antigens, and need not be excluded from immune-based therapies or clinical trials.

Engineered dendritic cells for gastrointestinal tumor immunotherapy: opportunities in translational research

Gastrointestinal (GI) malignancies are one of the most frequently occurring tumors found worldwide. Surgery remains the primary treatment for most solid tumors and adjuvant chemotherapy and radiotherapy are limited by lack of specificity and toxicity. In view of the poor survival rate, there is a great need to introduce new and effective therapeutic modalities. Recently, dendritic cells (DCs)-based vaccines are being explored as a promising therapeutic strategy but their success is limited by the tumor-induced immune escape mechanisms. This article provides a comprehensive analysis of clinical trials conducted using this approach. It also showcases the necessity of exploring nano-engineered strategies for improving the clinical utility of DC-vaccination for GI tract malignancies to overcome immune tolerance.

Cancer vaccines: should we be targeting patients with less aggressive disease?

There is enthusiasm for using vaccines to stimulate the immune system to treat cancer. In this article, the authors review the evolution of vaccines evaluated in clinical trials, starting with Phase III trials in metastatic disease and progressing to trials in the adjuvant setting. Data from these trials suggest that cancer vaccines may be more effective in patients with lower volume disease, and data from the E75 peptide vaccine trials suggest that vaccines may be most effective in less aggressive disease.

The mechanism of the anticancer function of M1 macrophages and their use in the clinic

M1-type macrophages are capable of inducing lysis in various types of cancer cells, but the mechanism of action is unclear. It has been noted that an "unknown protein" produced together with protease by activated macrophages is responsible for this action. Activated M1 macrophages have been recently reported to produce family 18 chitinases, all of which have been named chitotriosidase. Our experiments have demonstrated that family 18 chitinases work together with proteases and can damage various cancer cells both in vitro and in vivo. Thus, in this article, we suggest that the 50-kDa chitotriosidase is the reported "unknown protein". In addition, we discuss how to properly stimulate activated M1 macrophages to produce 50-kDa chitotriosidases and proteases for destroying cancer cells. Because family 19 chitinase has recently been reported to kill cancer cells, we also discuss the possibility of directly using human family 18 chitotriosidase and the humanized plant family 19 chitinase for cancer treatment.

The association between treatment-related lymphopenia and survival in newly diagnosed patients with resected adenocarcinoma of the pancreas

Fifty-three patients with resected pancreatic adenocarcinoma were studied to determine if adjuvant chemo-radiation causes severe lymphopenia and if this is associated with adverse outcomes. Total lymphocyte counts (TLC) were normal in 91% before adjuvant chemo-radiation. Two months later, TLC fell by 63% (p < .0001) with 45% of patients having TLC < 500 cells/mm(3). Median survival in patients with low TLC was 14 versus 20 months (p = .048). Multivariate analysis revealed a significant association between treatment related lymphopenia and survival (HR 2.2, p = .014). Adjuvant chemo-radiation induced lymphopenia is frequent, severe, and an independent predictor for survival in patients with resected pancreatic adenocarcinoma.

Anti-tumor immunity: myeloid leukocytes control the immune landscape

The immune surveillance hypothesis proposed over 50 years ago that many precancerous lesions are eliminated without a histological trace due to immunological pressure. Since then, it has become apparent that both the tumor and the anti-cancer immune response evolve over a long period to allow the eventual escape of nascent precancerous lesions into full-blown tumors. Although primarily focusing on loss of antigenicity, the immunoediting hypothesis has gradually evolved to appreciate the role of active immunosuppression in tumor progression, where myeloid leukocytes are increasingly recognized as the major driving force. This review highlights recent studies implicating how myeloid cells with antigen-presenting capabilities are co-opted by tumors to promote malignant progression. Because at least some advanced tumors remain significantly immunogenic, these new studies add a tweak to the immunoediting hypothesis as well as a rationale to block immunosuppressive mechanisms as a first-line intervention in cancer patients.

Cancer as an immune-mediated disease

The link between oncology and immunology has a long history and its development is forced by the necessity to develop innovative and highly efficient modalities for immunological destruction of malignant cells. The limited efficacy of surgery, chemotherapy and radiation also exemplify these issues, as these treatments do not eliminate all cancerous cells, do not address the immunosuppressive nature of the disease and can further impair the patient's immune response weakening patient's resistance to the cancer. Multidisciplinary analysis of the interaction between the immune system and cancer in preclinical and clinical settings suggests that the immune system is closely intertwined with both cancer pathogenesis and treatment. On the one hand, cancer is a manifestation of malfunctions in immunity, as malignant cells manage to escape recognition and elimination by the immune system. Chronic infections and inflammation associated with limited or polarized immune responses also contribute to carcinogenesis and tumor progression. The tumor immunoenvironment represents specific conditions and elements that support cancerous cell survival, proliferation and spreading. On the other hand, the specificity and strength of antitumor immunity is a powerful and efficient tool that can be used to recognize and destroy neoplastic cells or their supporting microenvironment. Understanding the role of the immune system in controlling and supporting tumor initiation, formation, growth and progression has crucial implications for cancer therapy and will therefore guide the future development of cancer immunotherapy and its combination with conventional therapies to achieve optimal antitumor effects in patients with different types of cancer.