The immunoregulatory mechanisms of carcinoma for its survival and development

Live or Heat-Killed Lactobacillus rhamnosus Aerosolization Decreases Adenomatous Lung Cancer Development in a Mouse Carcinogen-Induced Tumor Model

An immunosuppressive microenvironment in lung concurs to pre-malignant lesions progression to cancer. Here, we explore if perturbing lung microbiota, which contribute to immunosuppression, by antibiotics or probiotic aerosol interferes with lung cancer development in a mouse carcinogen-induced tumor model. Urethane-injected mice were vancomycin/neomycin (V/N)-aerosolized or live or dead L. rhamnosus GG (L.RGG)-aerosolized, and tumor development was evaluated. Transcriptional profiling of lungs and IHC were performed. Tumor nodules number, diameter and area were reduced by live or heat-killed L.RGG, while only a decrease in nodule diameter was observed in V/N-treated lungs. Both L.RGG and V/N reduced Tregs in the lung. In L.RGG-treated groups, the gene encoding the joining chain (J chain) of immunoglobulins was increased, and higher J chain protein and IgA levels were observed. An increased infiltration of B, NK and myeloid-derived cells was predicted by TIMER 2.0. The Kaplan–Meier plotter revealed an association between high levels of J chain mRNA and good prognosis in lung adenocarcinoma patients that correlated with increased B and CD4 T cells and reduced Tregs and M2 macrophages. This study highlights L.RGG aerosol efficacy in impairing lung cancer growth by promoting local immunity and points to this non-invasive strategy to treat individuals at risk of lung cancer.

Tumor-Infiltrating Dendritic Cells: Decisive Roles in Cancer Immunosurveillance, Immunoediting, and Tumor T Cell Tolerance

The tumor microenvironment plays a key role in progression of tumorigenesis, tumor progression, and metastasis. Accumulating data reveal that dendritic cells (DCs) appear to play a key role in the development and progression of metastatic neoplasia by driving immune system dysfunction and establishing immunosuppression, which is vital for tumor evasion of host immune response. Consequently, in this review, we will discuss the function of tumor-infiltrating DCs in immune cell signaling pathways that lead to treatment resistance, tumor recurrence, and immunosuppression. We will also review DC metabolism, differentiation, and plasticity, which are essential for metastasis and the development of lung tumors. Furthermore, we will take into account the interaction between myeloid cells and DCs in tumor-related immunosuppression. We will specifically look into the molecular immune-related mechanisms in the tumor microenvironment that result in reduced drug sensitivity and tumor relapse, as well as methods for combating drug resistance and focusing on immunosuppressive tumor networks. DCs play a crucial role in modulating the immune response. Especially, as cancer progresses, DCs may switch from playing an immunostimulatory to an inhibitory role. This article’s main emphasis is on tumor-infiltrating DCs. We address how they affect tumor growth and expansion, and we highlight innovative approaches for therapeutic modulation of these immunosuppressive DCs which is necessary for future personalized therapeutic approaches.

Advances and challenges of immunocheckpoint inhibitors in the treatment of primary liver cancer

Primary liver cancer (PLC) is one of the most common malignant tumors, which clinically characterized by occult onset, rapid development, easy recurrence and poor prognosis. With the rapid development of tumor immunotherapy research, tumor immunotherapy has also achieved remarkable clinical efficacy, and jointly promoted the overall improvement of tumor immunology from mechanism research to clinical transformation, from single discipline to multi-disciplinary integration. Immunotherapy has obvious advantages in treatment-related toxicity and efficacy compared with traditional therapy. In hepatocellular carcinoma (HCC), immunotherapy alone or in combination with other therapies may help to control tumor progression, and there are many immune checkpoint inhibitors (ICIs) widely used in clinical or ongoing clinical trials. However, tumor immunology research is still facing many challenges. How to effectively evaluate the efficacy, whether there are related biomarkers, the generation of immune tolerance and the lack of clinical trials to objectively evaluate the efficacy are still urgent problems to be solved, but it also brings new research opportunities for basic and clinical immunology researchers. The study of treatment of ICIs of PLC has become a hot spot in clinical research field. This paper summarizes and prospects the research progress and challenges of ICIs for PLC.

Formation of pre-metastatic bone niche in prostate cancer and regulation of traditional chinese medicine

Prostate cancer with bone metastasis has a high cancer-specific mortality. Thus, it is essential to delineate the mechanism of bone metastasis. Pre-metastatic niche (PMN) is a concept in tumor metastasis, which is characterized by tumor-secreted factors, reprogramming of stromal cells, and immunosuppression by myeloid-derived suppressor cells (MDSC), which is induced by bone marrow-derived cells (BMDC) in the target organ. However, PMN does not explain the predilection of prostate cancer towards bone metastasis. In this review, we discuss the initiation of bone metastasis of prostate cancer from the perspective of PMN and tumor microenvironment in a step-wise manner. Furthermore, we present a new concept called pre-metastatic bone niche, featuring inherent BMDC, to interpret bone metastasis. Moreover, we illustrate the regulation of traditional Chinese medicine on PMN.

Prognostic value of Dickkopf-1 and ß-catenin expression according to the antitumor immunity of CD8-positive tumor-infiltrating lymphocytes in biliary tract cancer

The role of β-catenin and Dickkopf-1 (DKK1) is dependent on the specific immunobiology of T cell inflammation in biliary tract cancer (BTC). We aimed to analyze the role of DKK1 or β-catenin as a prognostic factor in BTC, and determine the clinical associations of ß-catenin and DKK1 with CD8+ tumor-infiltrating lymphocytes (TIL). We used data from The Cancer Genome Atlas Research Network and the clinicopathological data of 145 patients with BTC who had undergone primary radical resection between 2006 and 2016. CD8+ TIL expression was a significant predictor of favorable overall survival (OS) and relapse-free survival (RFS) (median OS, 34.9 months in high-TIL, 16.7 months in low-TIL, P < 0.0001 respectively; median RFS, 27.1 months in high-TIL, 10.0 months in low-TIL, P < 0.0001 respectively). In the high-CD8+ TIL BTC group, the tumor expression of β-catenin and DKK1 had a significant negative impact on either OS or RFS. In the low-TIL BTC group, there were no differences according to ß-catenin and DKK1 expression. Cox regression multivariate analysis demonstrated that CD8+ TIL and β-catenin retained significant association with OS. Among patients with resected BTC, the β-catenin and DKK1 protein and high CD8+ TIL levels were associated with poor and good clinical outcomes, respectively.

Identifying cancer specific signaling pathways based on the dysregulation between genes

A large collection of studies has shown that the occurrence of cancer is related to the functional dysfunction of the pathways. Identification of cancer-related pathways could help researchers understand the mechanisms of complex diseases well. Whereas, most current signaling pathway analysis methods take no account of the gene interaction variations within pathways. Furthermore, considering that some pathways have connection with two or more cancer types, while some are likely to be cancer-type specific pathways. Identifying cancer-type specific pathways contributes to interpreting the different mechanisms of different cancer types. In this study, we first proposed a pathway analysis method named Pathway Analysis of Intergenic Regulation (PAIGR) to identify pathways with dysregulation between genes and compared the performance of this method with four existing methods on four colorectal cancer (CRC) datasets. The results showed that PAIGR could find cancer-related pathways more accurately. Moreover, in order to explore the relationship between the identified pathways and the cancer type, we constructed a pathway interaction network, in which nodes and edges represented pathways and interactions between pathways respectively. Highly connected pathways were considered to play a central role in an extensive range of biological processes, while sparsely connected pathways are considered to have certain specificity. Our results showed that pathways identified by PAIGR had a low nodal degree (i.e., a few numbers of interactions), which suggested that most of these pathways were cancer-type specific.

Pulmonary Inflammation and KRAS Mutation in Lung Cancer

Chronic lung infection and lung cancer are two of the most important pulmonary diseases. Respiratory infection and its associated inflammation have been increasingly investigated for their role in increasing the risk of respiratory diseases including chronic obstructive pulmonary disease (COPD) and lung cancer. Kirsten rat sarcoma viral oncogene (KRAS) is one of the most important regulators of cell proliferation, differentiation, and survival. KRAS mutations are among the most common drivers of cancer. Lung cancer harboring KRAS mutations accounted for ~25% of the incidence but the relationship between KRAS mutation and inflammation remains unclear. In this chapter, we will describe the roles of KRAS mutation in lung cancer and how elevated inflammatory responses may increase KRAS mutation rate and create a vicious cycle of chronic inflammation and KRAS mutation that likely results in persistent potentiation for KRAS-associated lung tumorigenesis. We will discuss in this chapter regarding the studies of KRAS gene mutations in specimens from lung cancer patients and in animal models for investigating the role of inflammation in increasing the risk of lung tumorigenesis driven primarily by oncogenic KRAS.

A sensitivity scale for targeting T cells with chimeric antigen receptors (CARs) and bispecific T-cell Engagers (BiTEs)

Although T cells can mediate potent antitumor responses, immune tolerance mechanisms often result in the deletion or inactivation of T cells that express T-cell receptors (TCRs) against potentially effective target epitopes. Various approaches have been devised to circumvent this problem. In one approach, the gene encoding an antibody against a cancer-associated antigen is linked, in the form of a single-chain variable fragment (scFv), to genes that encode transmembrane and signaling domains. This chimeric antigen receptor (CAR) is then introduced into T cells for adoptive T-cell therapy. In another approach, the anti-cancer scFv is fused to a scFv that binds to the CD3ε subunit of the TCR/CD3 complex. This fusion protein serves as a soluble, injectable product that has recently been termed bispecific T-cell engager (BiTE). Both strategies have now been tested in clinical trials with promising results, but the comparative efficacies are not known. Here, we performed a direct comparison of the in vitro sensitivity of each strategy, using the same anti-cancer scFv fragments, directed against a tumor-specific glycopeptide epitope on the sialomucin-like transmembrane glycoprotein OTS8, which results form a cancer-specific mutation of Cosmc. While both approaches showed specific responses to the epitope as revealed by T cell-mediated cytokine release and target cell lysis, CAR-targeted T cells were more sensitive than BiTE-targeted T cells to low numbers of antigens per cell. The sensitivity scale described here provides a guide to the potential use of these two different approaches.

Hematological reactions in the inhabitants of the Arctic on a polar night and a polar day

PURPOSE

The purpose of this study is to identify the features of hematological reactions in the inhabitants of the Arctic territory of the Kola Peninsula on a polar night and a polar day.

METHODS

The study included determining the hemogram, neutrograms, monocytograms, lymphocytograms, and phagocytic activity neutrophil granulocytes, enzyme immunoassay, flow cytometry.

RESULTS

It was established that during the polar night, there is an increase in the activity of migration of leukocytes from the marginal pool to the circulating pool, an increase in the intensity of phagocytosis by neutrophils, an increase in the concentrations of noradrenaline, cortisol, as well as an increase in hyperergic reactions involving immunoglobulin E and inhibitory processes due to an increase in interleukin-10.

CONCLUSION

A prolonged lack of sunlight causes a decrease in the reserve capacity for regulating homeostasis and forces the body to use proliferative reactions, which is reflected in the increase in stab neutrophils, large lymphocytes in the structure of the lymphocytogram and CD10+ lymphocytes. In winters, the frequency of neutropenia registration also increases to 13% of cases, the deficit of phagocytic activity of neutrophils; lymphopenia is recorded in 20% with T-helper deficiency (37%). A part of the population probably has a relatively high degree of vulnerability to the action of natural environmental factors and is not able to completely restore the initial levels of the effectiveness of adaptation reactions in the summer. So at the end of the polar day in 8% of adults born in the north, neutropenia is recorded and in 21%-lymphopenia.

Clinicopathologic significance of human leukocyte antigen class I expression in patients with stage II and III gastric cancer

Human leukocyte antigen class I (HLA I) molecules composed of alpha (heavy) chain, including HLA-A, -B, or -C encoded by HLA genes, and beta-2-microglobulin (β2M) are membrane proteins on all nucleated cells that display peptide antigens for recognition by CD8-positive cytotoxic T cells. Here, we examined the clinicopathologic signification of HLA I expression in patients with gastric cancer (GC). Immunohistochemistry was performed to detect HLA A/B/C, β2M, CD8, p53, and programmed death-ligand 1 (PD-L1) in the center and invasive margin of the tumor in 395 stage II and III GCs using tissue array method. Additionally, Epstein-Barr virus (EBV) infection and microsatellite instability (MSI) status were investigated. Negative expression of HLA A/B/C and β2M was observed in 258 (65.3%) and 235 (59.5%) of 395 stage II and III GCs, respectively. Negative HLA I expression was significantly associated with aggressive clinicopathologic features. Furthermore, negative expression of HLA A/B/C and β2M was inversely correlated with CD8-positive cytotoxic T cell infiltration, EBV-positivity, and PD-L1 expression (all p < 0.001). Patients with HLA A/B/C-negative GC had worse overall survival (OS) (p = 0.019) and combined analysis with both HLA A/B/C and β2M expression status significantly predicted OS in univariate (p = 0.004) and multivariate survival analysis (p = 0.016). Negative expression of HLA A/B/C and β2M was frequently observed in stage II and III GCs, particularly with the aggressive clinicopathologic features, and correlated with an unfavorable prognosis and host immune response status. These findings contribute to further development of immunotherapy.

Negative roles of B7-H3 and B7-H4 in the microenvironment of cervical cancer

Although persistent human papilloma virus (HPV) infection exerts a crucial influence on cervical carcinogenesis, other factors are also involved in its development, such as intraepithelial lesions and cervical cancer. B7-H3 and B7-H4, which have been reported to be co-regulatory ligands in the B7 family, had been found to be overexpressed in cervical cancer and correlated with adverse clinicopathological features and poor prognosis in our previous studies. In this study, we sought to explore the effects of B7-H3 and B7-H4 on the cervical microenvironment. Among several immune cytokines, interleukin-10 (IL-10) and transforming growth factor (TGF) β1 stand out as important immunosuppressive factors. Our studies found that IL-10 expression increased with pathological change levels and significantly correlated with cervical cancer differentiation (P < 0.05). TGF-β1 correlated with lymph node metastasis (LNM) (P < 0.01). Expression of B7-H3 and B7-H4 positively correlated with the expression of IL-10 and TGF-β1. After co-culture, we found that overexpression of B7-H3 and B7-H4 in cervical cancer cell lines resulted in activation of the cell cycle and decreased apoptosis of U-937 cells. In addition, the contents of IL-10 and TGF-β1, as well as their protein expression levels, increased in co-culture supernatants in U-937 cells, suggesting regulation by the p-JAK2/STAT3 pathway. The in vivo results demonstrated that with the increasing expression of B7-H3/B7-H4, the expression of IL-10 and TGF-β1 also increased significantly. Overall, the expression of B7-H3 and B7-H4 favored an immunosuppressive microenvironment by promoting the production of IL-10 and TGF-β1, thereby resulting in progression of cervical carcinogenesis.

Prevention of Prostate Tumor Development by Stimulation of Antitumor Immunity Using a Standardized Herbal Extract (Deep Immune®) in TRAMP Mice

Low-risk prostate cancer (PCa) does not require immediate treatment, but PCa progression after years of active surveillance will need the treatment. This study was to test the efficacy of immunostimulant Deep Immune (DI) in controlling PCa progression. DI is an extract of eight different medicinal herbs. In vitro activity of DI was determined by phagocytosis activation using flow cytometric analysis of fluorescence-labeled latex bead uptake, expression of immune-modulating 84 genes using PCRarray, and tumor killing using coculturing with immune cells. Anti-PCa activity of DI in vivo was examined in male TRAMP mice. In vitro DI stimulated phagocytosis and expression of a panel of inflammatory mediators (C4b, CXCL3, lymphotoxin, NOS2, TLR1, TNF, and TNFSF14) in cultured macrophages and increased tumor killing of both macrophages and TRAMP mouse splenocytes. Daily intake of this herbal product significantly suppressed the tumor size (P = 0.0368) with lower histopathologic scores (P = 0.0364) in TRAMP mice, which were associated with an increase in both splenocyte cytotoxicity against tumor cells and numbers of CD8 T cells, macrophages, and dendritic cells in the spleens in vivo. In conclusion, daily intake of DI prevents PCa progression in TRAMP mice, suggesting the possible effectiveness of the immunostimulant herbal products on prevention of PCa progression after diagnosis of low-risk PCa.

Neutrophil-to-lymphocyte Ratio is a Predictive Marker for Invasive Malignancy in Intraductal Papillary Mucinous Neoplasms of the Pancreas

OBJECTIVE

To evaluate the correlation between neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) values, and the presence of invasive carcinoma in patients with intraductal papillary mucinous neoplasm (IPMN).

BACKGROUND

NLR and (PLR) are inflammatory markers that have been associated with overall survival in patients with invasive malignancies, including pancreatic cancer.

METHODS

We retrospectively reviewed 272 patients who underwent surgical resection for histologically confirmed IPMN from January 1997 to July 2015. NLR and PLR were calculated and coevaluated with additional demographic, clinical, and imaging data for possible correlation with IPMN-associated carcinoma in the form of a predictive nomogram.

RESULTS

NLR and PLR were significantly elevated in patients with IPMN-associated invasive carcinoma (P < 0.001). In the multivariate analysis, NLR value higher than 4 (P < 0.001), IPMN cyst of size more than 3 cm (P < 0.001), presence of enhanced solid component (P = 0.014), main pancreatic duct dilatation of more than 5 mm (P < 0.001), and jaundice (P < 0.001) were statistically significant variables. The developed statistical model has a c-index of 0.895. Implementation of the statistically significant variables in a predictive nomogram provided a reliable point system for estimating the presence of IPMN-associated invasive carcinoma.

CONCLUSIONS

NLR is an independent predictive marker for the presence of IPMN-associated invasive carcinoma. Further prospective studies are needed to assess the predictive ability of NLR and how it can be applied in the clinical setting.

Spontaneous regression of transverse colon cancer: a case report

Spontaneous regression (SR) of many malignant tumors has been well documented, with an approximate incidence of one per 60,000–100,000 cancer patients. However, SR of colorectal cancer (CRC) is very rare, accounting for less than 2% of such cases. We report a case of SR of transverse colon cancer in an 80-year-old man undergoing outpatient follow-up after surgical treatment of early gastric cancer. Colonoscopy (CS) revealed a Borrmann type II tumor in the transverse colon measuring 30 × 30 mm. Because the patient underwent anticoagulant therapy, we did not perform a biopsy at that time. A second CS was performed 1 week after the initial examination and revealed tumor shrinkage to a diameter of 20 mm and a shift to the Borrmann type III morphology. Biopsy revealed a poorly differentiated adenocarcinoma. One week after the second CS, we performed a partial resection of the transverse colon and D2 lymph node dissection. Histopathology revealed inflammatory cell infiltration and fibrosis from the submucosal to muscularis propria layers in the absence of cancer cells, leading to pathological staging of pStage 0 (T0N0). The patient had an uneventful recovery, and CS performed at 5 months postoperatively revealed the absence of a tumor in the colon and rectum. The patient continues to be followed up as an outpatient at 12 months postoperatively, and no recurrence has been observed.

DMBT1 expression in biliary carcinogenesis with correlation of clinicopathological data

AIMS

Deleted in malignant brain tumours 1 (DMBT1) exerts functions in the regulation of epithelial differentiation and inflammation and has been proposed as a tumour suppressor. Because chronic inflammation is a hallmark of cholangiocarcinogenesis, the aim of this study was to investigate the expression of DMBT1 in biliary tract cancer (BTC) and to correlate this expression with clinicopathological data.

METHODS AND RESULTS

The expression of DMBT1 protein was examined immunohistochemically in 157 BTC patients [41 intrahepatic (ICC), 60 extrahepatic cholangiocarcinomas (ECC) and 56 adenocarcinomas of the gallbladder (GBAC)]. Additionally, 56 samples of high-grade biliary intraepithelial neoplasia (BilIN 3) and 92 corresponding samples of histological non-neoplastic biliary tract tissues were included. DMBT1 expression was increased significantly in BilIN 3 compared to normal tissue (P < 0.0001) and BTC (P < 0.0001). BTC showed no significant difference in DMBT1 expression compared to non-neoplastic biliary tissue (P = 0.315). Absent DMBT1 expression in non-neoplastic biliary tissue of BTC patients was associated with poorer survival (P = 0.027). DMBT1 expression was correlated significantly with patients' age (P < 0.001).

CONCLUSION

DMBT1 is expressed differently in cholangiocarcinogenesis and poorer patients' survival rates are associated with absent DMBT1 expression in non-neoplastic biliary tissue, suggesting a tumour-suppressive role of DMBT1 in early cholangiocarcinogenesis.

Major histocompatibility complex class I expression impacts on patient survival and type and density of immune cells in biliary tract cancer

BACKGROUND

Biliary tract cancers (BTC) are rare malignant tumours with a poor prognosis. Previously, we have presented a detailed characterisation of the inflammatory infiltrate in BTC. Here, we analysed the impact of the expression of major histocompatibility complex class I (MHC I) on patient survival and the quantity, as well as the quality of tumour-infiltrating immune cell types in BTC.

METHODS

MHC I expression was assessed semi-quantitatively in 334 BTC, including extrahepatic (n=129) and intrahepatic cholangiocarcinomas (n=146), as well as adenocarcinomas of the gallbladder (n=59). In addition, 71 high-grade biliary intraepithelial lesions (BilIN 3) were included. Results were correlated with data on antitumour inflammation and investigated with respect to their association with clinicopathological variables and patient survival.

RESULTS

BTC showed a wide spectrum of different MHC I expression patterns ranging from complete negativity in some tumours to strong homogenous expression in others. In BilIN 3, significantly higher MHC I expression levels were seen compared to invasive tumours (P=0.004). Patients with strong tumoural MHC I expression had a significantly higher overall survival probability (median survival benefit: 8 months; P=0.006). MHC I expression strongly correlated with the number of tumour-infiltrating T-lymphocytes (CD4(+) and CD8(+)) and macrophages.

CONCLUSIONS

Differences of MHC I expression predict patient outcome and show correlations with specific components of the inflammatory infiltrate in BTC. These findings contribute to a better understanding of immune response and immune escape phenomena in cholangiocarcinogenesis.

Vitamin D3 enhances the tumouricidal effects of 5-Fluorouracil through multipathway mechanisms in azoxymethane rat model of colon cancer

Background

Vitamin D3 and its analogues have recently been shown to enhance the anti-tumour effects of 5- Fluorouracil (5-FU) both in vitro and in xenograft mouse model of colon cancer. This study measured the potential mechanism(s) by which vitamin D3 could synergise the tumouricidal activities of 5-FU in azoxymethane (AOM) rat model of colon cancer.

Methods

Seventy-five male Wistar rats were divided equally into 5 groups: Control, AOM, AOM-treated by 5-FU (5-FU), AOM-treated by vitamin D3 (VitD3), and AOM-treated by 5-FU + vitamin D3 (5-FU/D). The study duration was 15 weeks. AOM was injected subcutaneously for 2 weeks (15 mg/kg/week). 5-FU was injected intraperitoneally in the 9th and 10th weeks post AOM (8 total injections were given: 12 mg/kg/day for 4 successive days, then 6 mg/kg every other day for another 4 doses) and oral vitamin D3 (500 IU/rat/day; 3 days/week) was given from week 7 post AOM till the last week of the study. The colons were collected following euthanasia for gross and histopathological examination. The expression of β-catenin, transforming growth factor-β1 (TGF-β1), TGF-β type 2 receptor (TGF-βR2), smad4, inducible nitric oxide synthase (iNOS), and heat shock protein-90 (HSP-90) proteins was measured by immunohistochemistry. In colonic tissue homogenates, quantitative RT-PCR was used to measure the mRNA expression of Wnt, β-catenin, Dickkopf-1 (DKK-1) and cyclooxygenase-2 (COX-2) genes, while ELISA was used to measure the concentrations of TGF-β1, HSP-90 and COX-2 proteins.

Results

Monotherapy with 5-FU or vitamin D3 significantly decreased the number of grown tumours induced by AOM (P < 0.05); however, their combination resulted in more significant tumouricidal effects (P < 0.05) compared with monotherapy groups. Mechanistically, vitamin D3/5-FU co-therapy significantly decreased the expression of Wnt, β-catenin, iNOS, COX-2 and HSP-90 and significantly increased the expression of DKK-1, TGF-β1, TGF-βR2, smad4 (P < 0.05), in comparison with their corresponding monotherapy groups.

Conclusions

Vitamin D3 and 5-FU synergise together and exhibit better anticancer effects by modulating Wnt/β-catenin pathway, TGF-β1 signals, iNOS, COX-2 and HSP-90. Further studies are required to illustrate the clinical value of vitamin D supplementation during the treatment of colon cancer with 5-FU in human patients.

High levels of soluble MICA are significantly related to increased disease-free and disease-specific survival in patients with cervical adenocarcinoma

Downregulation of major histocompatibility complex class I chain-related molecule A (MICA) and upregulation of human leukocyte antigen G (HLA-G) on the tumor cells are important immune escape mechanisms for different epithelial tumors. In addition, upregulation of the soluble forms of the latter molecules in serum leads to peripheral T-cell and natural killer (NK)-cell tolerance. As for cervical cancer, it remains unknown whether soluble MICA (sMICA) and soluble HLA-G (sHLA-G) concentrations are related to tumor characteristics or patient survival rates. We measured sMICA and sHLA-G in pre-treatment sera of a large cohort of cervical cancer patients (n = 366) by enzyme-linked immunosorbent assay (ELISA). We detected a median sMICA of 174.73 pg/ml and a median sHLA-G of 5.35 U/ml. We did not find an association between sHLA-G levels and clinicopathological characteristics. In adenocarcinoma, low sMICA concentration was positively related to recurrent disease, a higher International Federation of Gynecology and Obstetrics (FIGO) stage and vaginal involvement (Mann-Whitney U-test; P = 0.018, P = 0.042 and P = 0.013, respectively). In the latter patient group, high sMICA levels were associated with better disease-free survival (DFS) and disease-specific survival (DSS) (P = 0.011 and P = 0.047). After adjusting for confounding factors, high sMICA proved to be an independent predictor for a better DFS and DSS [HR 0.16; 95% confidence interval (CI) 0.04-0.64; P = 0.009 and HR 0.12; 95% CI 0.03-0.50; P = 0.004]. sHLA-G did not influence survival in cervical cancer patients, regardless of histology. We conclude that cervical adenocarcinoma patients with high sMICA levels have an increased DFS and DSS. This data warrants a prospective trial to study the functional role of sMICA in cervical adenocarcinoma.

Embryonic stem cell-derived haematopoietic progenitor cells down-regulate the CD3 ξ chain on T cells, abrogating alloreactive T cells

Murine embryonic stem (ES) cell-derived haematopoietic progenitor cells (HPCs) engraft and populate lymphoid organs. In vivo, HPCs engraft across MHC barriers protecting donor-type allografts from rejection. However, the underlying phenomenon remains elusive. Here, we sought to determine the mechanism by which ES cell-derived HPCs regulate alloreactive T cells. We used the 2C mouse, which expresses a transgenic T-cell receptor against H2-L(d) to determine whether HPCs are deleted by cytotoxic T lymphocytes (CTLs). Previously, we reported that HPCs express MHC class I antigens poorly and do not express class II antigens. In vitro stimulated 2C CTLs failed to lyse H2-L(d) HPCs in a standard 4-hr (51) chromium release assay. Similarly, when the HPCs were tested in an ELISPOT assay measuring the release of interferon-γ by CTLs, HPCs failed to induce CTL degranulation. In addition, mice that were injected with HPCs showed a marked decrease in T-cell responses to alloantigen and CD3 stimulation, but showed a normal response to PMA/ionomycin, suggesting that HPCs impaired T-cell signalling through the T-cell receptor/CD3 complex. Here, we show that HPCs secrete arginase, an enzyme that scavenges l-arginine, leading to metabolites that down-regulate CD3 ζ chain. Indeed an arginase inhibitor partially restored expression of the CD3 ζ chain, implicating arginase 1 in the down-regulation of T cells. This previously unrecognized property of ES cell-derived HPCs could positively enhance the engraftment of ES cell-derived HPCs across MHC barriers by preventing rejection.

Detailed analysis and follow-up studies of a high-throughput screening for indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors

Indoleamine 2,3-dioxygenase 1 (IDO1) is a key regulator of immune responses and therefore an important therapeutic target for the treatment of diseases that involve pathological immune escape, such as cancer. Here, we describe a robust and sensitive high-throughput screen (HTS) for IDO1 inhibitors using the Prestwick Chemical Library of 1200 FDA-approved drugs and the Maybridge HitFinder Collection of 14,000 small molecules. Of the 60 hits selected for follow-up studies, 14 displayed IC50 values below 20 μM under the secondary assay conditions, and 4 showed an activity in cellular tests. In view of the high attrition rate we used both experimental and computational techniques to identify and to characterize compounds inhibiting IDO1 through unspecific inhibition mechanisms such as chemical reactivity, redox cycling, or aggregation. One specific IDO1 inhibitor scaffold, the imidazole antifungal agents, was chosen for rational structure-based lead optimization, which led to more soluble and smaller compounds with micromolar activity.

Immunogenicity of murine solid tumor models as a defining feature of in vivo behavior and response to immunotherapy

Immune profiling has been widely used to probe mechanisms of immune escape in cancer and identify novel targets for therapy. Two emerging uses of immune signatures are to identify likely responders to immunotherapy regimens among individuals with cancer and to understand the variable responses seen among subjects with cancer in immunotherapy trials. Here, the immune profiles of 6 murine solid tumor models (CT26, 4T1, MAD109, RENCA, LLC, and B16) were correlated to tumor regression and survival in response to 2 immunotherapy regimens. Comprehensive profiles for each model were generated using quantitative reverse transcriptase polymerase chain reaction, immunohistochemistry, and flow cytometry techniques, as well as functional studies of suppressor cell populations (regulatory T cells and myeloid-derived suppressor cells), to analyze intratumoral and draining lymphoid tissues. Tumors were stratified as highly or poorly immunogenic, with highly immunogenic tumors showing a significantly greater presence of T-cell costimulatory molecules and immune suppression in the tumor microenvironment. An absence of tumor-infiltrating cytotoxic T lymphocytes and mature dendritic cells was seen across all models. Delayed tumor growth and increased survival with suppressor cell inhibition and tumor-targeted chemokine+/-dendritic cells vaccine immunotherapy were associated with high tumor immunogenicity in these models. Tumor MHC class I expression correlated with the overall tumor immunogenicity level and was a singular marker to predict immunotherapy response with these regimens. By using experimental tumor models as surrogates for human cancers, these studies demonstrate how select features of an immune profile may be utilized to identify patients most likely to respond to immunotherapy regimens.

Cytotoxic reaction mediators: granzymes A and B in women with ovarian cancer

The purpose of this work was the assessment of cytotoxic reaction mediators - granzymes A and B in the serum of women with ovarian tumors. The study included 120 women with proven ovarian tumors. The control group consisted of 60 healthy women in whom no pathological changes within the reproductive system were detected. Concentrations of granzymes A and B were measured by enzyme-linked immunosorbent (ELISA) assay. The highest concentrations of the studied parameters were observed in serum of women with ovarian cancer. Moreover, the concentrations of granzymes A and B in patients with ovarian cancer were substantially increased in comparison to concentrations in patients with ovarian cystadenomas (P < 0.0001) or ovarian teratomas (P < 0.0001).

Silica-induced chronic inflammation promotes lung carcinogenesis in the context of an immunosuppressive microenvironment

The association between inflammation and lung tumor development has been clearly demonstrated. However, little is known concerning the molecular events preceding the development of lung cancer. In this study, we characterize a chemically induced lung cancer mouse model in which lung cancer developed in the presence of silicotic chronic inflammation. Silica-induced lung inflammation increased the incidence and multiplicity of lung cancer in mice treated with N-nitrosodimethylamine, a carcinogen found in tobacco smoke. Histologic and molecular analysis revealed that concomitant chronic inflammation contributed to lung tumorigenesis through induction of preneoplastic changes in lung epithelial cells. In addition, silica-mediated inflammation generated an immunosuppressive microenvironment in which we observed increased expression of programmed cell death protein 1 (PD-1), transforming growth factor-β1, monocyte chemotactic protein 1 (MCP-1), lymphocyte-activation gene 3 (LAG3), and forkhead box P3 (FOXP3), as well as the presence of regulatory T cells. Finally, the K-RAS mutational profile of the tumors changed from Q61R to G12D mutations in the inflammatory milieu. In summary, we describe some of the early molecular changes associated to lung carcinogenesis in a chronic inflammatory microenvironment and provide novel information concerning the mechanisms underlying the formation and the fate of preneoplastic lesions in the silicotic lung.

Mannan-modified adenovirus encoding VEGFR-2 as a vaccine to induce anti-tumor immunity

PURPOSE

Dendritic cell (DC) vaccines are a promising immunotherapeutic approach for treatment and prevention of cancer. While this methodology is widely accepted, it also has some limitations. Antigen-presenting cells including DCs express the mannan receptor (MR). The delivery of a mannan-modified tumor antigen to the MR has been demonstrated to be efficient. Vascular endothelial growth factor receptor-2 (VEGFR-2) is mainly responsible for angiogenesis and tumor growth. The goal of our study was to deliver VEGFR-2 to DCs by means of mannan-modified adenovirus.

METHODS

VEGFR-2 recombinant adenovirus modified with oxidized mannan was constructed as a tumor vaccine to immunize mice in vivo. IFN-γ in mouse sera and spleen was detected by ELISA and ELISPOT. The killing activity of cytotoxic T lymphocyte (CTL) against VEGFR-2 was measured with a lactate dehydrogenase assay. Vessel densities in tumor tissues were detected by immunohistochemistry. Flow cytometry was used to test CD4(+) and CD8(+) T-cell counts in tumor tissues.

RESULTS

The vaccine exhibited both protective and therapeutic efficacy in the inhibition of tumor growth and markedly prolonged survival in mice. Protection against metastasis was also observed. Furthermore, vaccination led to greater IFN-γ and VEGFR-2-specific CTLs. The specific immunity resulted in the suppression of angiogenesis and an increase in CD8(+) cells in tumor tissues.

CONCLUSION

Oxidized mannan-modified adenovirus expressing VEGFR-2 could extraordinarily stimulate both protective and therapeutic immune response in a mice model. Our data suggest that the combination of cancer immunity and anti-angiogenesis via modified mannan is a promising strategy in tumor prophylaxis and therapy.

Prognostic impact of tumour-infiltrating immune cells on biliary tract cancer

BACKGROUND

Biliary tract cancers (BTC) are relatively rare malignant tumours with poor prognosis. It is known from other solid neoplasms that antitumour inflammatory response has an impact on tumour behaviour and patient outcome. The aim of this study was to provide a comprehensive characterisation of antitumour inflammatory response in human BTC.

METHODS

Tumour-infiltrating T lymphocytes (CD4+, CD8+, and Foxp3+), natural killer cells (perforin+), B lymphocytes (CD20+), macrophages (CD68+) as well as mast cells (CD117+) were assessed by immunohistochemistry in 375 BTC including extrahepatic (ECC; n=157), intrahepatic (ICC; n=149), and gallbladder (GBAC; n=69) adenocarcinomas. Overall and intraepithelial quantity of tumour-infiltrating immune cells was analysed. Data were correlated with clinicopathological variables and patient survival.

RESULTS

The most prevalent inflammatory cell type in BTC was the T lymphocyte. Components of the adaptive immune response decreased, whereas innate immune response components increased significantly in the biliary intraepithelial neoplasia - primary carcinoma - metastasis sequence. BTC patients with intraepithelial tumour-infiltrating CD4+, CD8+, and Foxp3+ T lymphocytes showed a significantly longer overall survival. Number of total intraepithelial tumour-infiltrating Foxp3+ regulatory T lymphocytes (HR: 0.492, P=0.002) and CD4+ T lymphocytes (HR: 0.595, P=0.008) were tumour grade- and UICC-stage-independent prognosticators. The subtype-specific evaluation revealed that the tumour-infiltrating lymphocytic infiltrate is a positive outcome predictor in ECC and GBAC but not in ICC.

CONCLUSION

Our findings characterise the immune response in cholangiocarcinogenesis and identify inflammatory cell types that influence the outcome of BTC patients. Further, we show that BTC subtypes show relevant differences with respect to density, quality of inflammation, and impact on patient survival.

Liver sinusoidal endothelial cells contribute to CD8 T cell tolerance toward circulating carcinoembryonic antigen in mice

Immunity against cancer is impeded by local mechanisms promoting development of tumor-specific T cell tolerance, such as regulatory T cells, myeloid-derived suppressor cells, or immunosuppressive factors in the tumor microenvironment. The release of soluble antigens, such as carcinoembryonic antigen (CEA) from colorectal carcinoma (CRC) cells, has been investigated for diagnostic purposes, but not for its immunological consequences. Here, we address the question of whether soluble CEA influences tumor-specific immunity. Mice were injected with soluble CEA protein, and CEA-specific CD8 T cells were analyzed for their phenotype and functionality by means of restimulation ex vivo or antitumor efficacy in vivo. We furthermore characterized the CD8 T cell population in peripheral blood mononuclear cell (PBMCs) from healthy donors and colorectal carcinoma patients. In mice, circulating CEA was preferentially taken up in a mannose receptor-dependent manner and cross-presented by liver sinusoidal endothelial cells, but not dendritic cells, to CD8 T cells. Such systemically circulating CEA promoted tolerization of CEA-specific CD8 T cells in the endogenous T cell repertoire through the coinhibitory molecule B7H1. These CD8 T cells were not deleted but were rendered nonresponsive to antigen-specific stimulation and failed to control growth of CEA-expressing tumor cells. These nonresponsive CD8 T cells were phenotypically similar to central memory T cells being CD44(high) CD62L(high) CD25(neg) . We found T cells with a similar phenotype in PBMCs of healthy donors and at increased frequency also in patients with colorectal carcinoma.

CONCLUSION

Our results provide evidence for the existence of an unrecognized tumor immune escape involving cross-presentation of systemically circulating tumor antigens that may influence immunotherapy of cancer.

Galectin labeling of cells from paraffinized tissues may serve as a diagnostic tool in the detection and classification of thyroid carcinomas

This study seeks to determine whether the relative levels of attachment to galectins 1 and 3 of cells from thyroid tissues embedded in paraffin blocks can differentiate thyroid tumors from normal tissues. A total of 48 thyroid paraffin sample blocks from 4 groups of patients were analyzed: 12 samples served as controls, 12 samples were from patients with thyroid adenoma, 12 samples were from patients with thyroid follicular carcinoma, and 12 samples were from patients with thyroid papillary carcinoma. The relative attachment of cells to galectins 1 and 3 antigens was determined using the InnoCyte™ ECM Cell Adhesion kit at different cell sample concentrations. All of the samples from thyroid tissue preparations showed attachment to galectins 1 and 3. The samples from tissues with a diagnosis of adenoma, follicular and papillary carcinoma showed an increased adherence to galectins 1 and 3 relative to the controls. Significant differences were found between the means of the adherent cells from the adenomas compared with the follicular and papillary carcinoma samples. When the outcomes from the galectins 1 and 3 cell surface binding were compared, no statistical differences were found. The cells from adenoma and carcinoma samples show more adhesion to galectins 1 and 3 than cells from the control samples. The samples prepared from follicular and papillary carcinomas show more cells adherent to galectins 1 and 3 than those from the adenomas.

The potential beneficial effects of drugs on the immune response to vaccination

Many immunotherapeutic agents in phase II cancer studies have given optimistic results, which were not confirmed in larger randomized studies. Here we explore the evidence that, contrary to previous opinion, many chemotherapeutic agents and other classes of drugs may enhance the response to therapeutic vaccines by reducing inflammation and/or by inhibiting regulatory T lymphocytes or myeloid-derived suppressor cells. In addition, some of these agents, such as the immunomodulatory drugs, may produce marked costimulatory activities as in the case of lenalidomide, which also has marked anti-inflammatory properties. With the first approval for a vaccine-based therapy for prostate cancer, we propose that many more vaccines will be able to achieve approval, especially when combined with the optimal chemotherapy and/or immunomodulatory drug schedule.

The immunosuppressive factors IL-10, TGF-β, and VEGF do not affect the antigen-presenting function of CD40-activated B cells

Background

Progress in recent years strengthened the concept of cellular tumor vaccinations. However, a crucial barrier to successful cancer immunotherapy is tumor-mediated immunosuppression. Tumor-derived soluble factors such as IL-10, TGF-β, and VEGF suppress effector cells either directly or indirectly by disruption of dendritic cell (DC) differentiation, migration and antigen presentation. Human B cells acquire potent immunostimulatory properties when activated via CD40 and have been shown to be an alternative source of antigen-presenting cells (APCs) for cellular cancer vaccines. Nevertheless, in contrast to DCs little knowledge exists about their susceptibility to tumor derived immunosuppressive factors. Thus, we assessed whether IL-10, TGF-β, or VEGF do affect key aspects of the immunostimulatory function of human CD40-activated B cells.

Methods

Cell surface expression of adhesion and costimulatory molecules and the proliferation capacity of CD40-activated B cells were compared to untreated controls by flow cytometry. Migration towards important chemokines of secondary lymph organs was measured with or without exposure to the immunosuppressive cytokines. Finally, an influence on T cell stimulation was investigated by allogeneic mixed lymphocyte reactions. For statistical analysis Student’s t test or two-way analysis of variance followed by Bonferroni's post-hoc test was used to compare groups. P values of <0.05 were considered statistically significant.

Results

Neither cell adhesion nor the expression of MHC class II and costimulatory molecules CD80 and CD86 was inhibited by addition of IL-10, TGF-β, or VEGF. Likewise, the proliferation of CD40-activated B cells was not impaired. Despite being exposed to IL-10, TGF-β, or VEGF the B cells migrated equally well as untreated controls to the chemokines SLC and SDF-1α. Most importantly, the capacity of CD40-activated B cells to stimulate CD4⁺ and CD8⁺ T cells remained unaffected.

Conclusion

Our findings suggest that key immunostimulatory functions of CD40-activated B cells are resistant to inhibition by the immunosuppressive factors IL-10, TGF-β, and VEGF. This supports considerations to use ex vivo generated CD40-activated B cells as a promising alternative or additional APC for cellular immunotherapy, especially in settings where these immunosuppressive cytokines are present in tumor environment.

A randomised controlled pilot feasibility study of the physical and psychological effects of an integrated support programme in breast cancer

A pilot study was conducted to assess recruitment and effectiveness of an integrated support programme in women with breast cancer. Twelve participants were randomised to receive medical care with or without the support programme. Psychosocial questionnaires and immune/hormonal assays were completed at baseline, three and six months. Recruitment was problematic. In the intervention group, mental fatigue was significantly improved (p = 0.016) compared to controls; increased NK cell activity suggested an improvement in immune function. Total stress (p = 0.009), anxiety (p = 0.032) and endocrine-specific (p = 0.032) symptoms were significantly improved in the controls. A large-scale randomisation trial appears warranted, dependent upon effective recruitment.

Pathway-based evaluation in early onset colorectal cancer suggests focal adhesion and immunosuppression along with epithelial-mesenchymal transition

Colorectal cancer (CRC) has one of the highest incidences among all cancers. The majority of CRCs are sporadic cancers that occur in individuals without family histories of CRC or inherited mutations. Unfortunately, whole-genome expression studies of sporadic CRCs are limited. A recent study used microarray techniques to identify a predictor gene set indicative of susceptibility to early-onset CRC. However, the molecular mechanisms of the predictor gene set were not fully investigated in the previous study. To understand the functional roles of the predictor gene set, in the present study we applied a subpathway-based statistical model to the microarray data from the previous study and identified mechanisms that are reasonably associated with the predictor gene set. Interestingly, significant subpathways belonging to 2 KEGG pathways (focal adhesion; natural killer cell-mediated cytotoxicity) were found to be involved in the early-onset CRC patients. We also showed that the 2 pathways were functionally involved in the predictor gene set using a text-mining technique. Entry of a single member of the predictor gene set triggered a focal adhesion pathway, which confers anti-apoptosis in the early-onset CRC patients. Furthermore, intensive inspection of the predictor gene set in terms of the 2 pathways suggested that some entries of the predictor gene set were implicated in immunosuppression along with epithelial-mesenchymal transition (EMT) in the early-onset CRC patients. In addition, we compared our subpathway-based statistical model with a gene set-based statistical model, MIT Gene Set Enrichment Analysis (GSEA). Our method showed better performance than GSEA in the sense that our method was more consistent with a well-known cancer-related pathway set. Thus, the biological suggestion generated by our subpathway-based approach seems quite reasonable and warrants a further experimental study on early-onset CRC in terms of dedifferentiation or differentiation, which is underscored in EMT and immunosuppression.

Pre-existing Fas ligand (FasL) in cancer cells elicits tumor-specific protective immunity, but delayed induction of FasL expression after inoculation facilitates tumor formation

Overexpression of Fas ligand (FasL) in cancer cells elicits potential antitumor effects via recruitment of neutrophils. Conversely, FasL-expressing tumors may counterattack tumor-infiltrating lymphocytes by delivering apoptotic death signals via Fas/FasL interactions, which may lead to tumor escape. In order to distinguish the role of FasL in antitumor activity and tumor progression, Lewis lung carcinoma cells (LLC-1) were used to establish the cell line LLC-FasL, in which FasL expression was repressed by doxycycline (Dox) treatment and induced in the absence of Dox. LLC-FasL cells promote tumor regression when expressing FasL, whereas tumor outgrowth is observed by depletion of FasL expression. To investigate whether initial expression of FasL during tumor formation is critical for FasL-mediated tumor regression, Dox-treated LLC-FasL cells were inoculated into Dox-treated mice, but Dox treatment was stopped 5 days after inoculation. When low cell numbers were inoculated, we observed 80% survival and no tumor formation, whereas no mice survived inoculation with high cell numbers, despite the delayed induction of FasL by Dox withdrawal. The inoculation of a high density of cells may establish a favorable tumor microenvironment before the expression of FasL. Our findings demonstrate that FasL may elicit antitumor activity when it is initially present on injected cancer cells and thus can act prior to tumor microenvironment formation. Furthermore, a well-established tumor microenvironment abrogates FasL-mediated antitumor activity.

CD25+ T cell depletion impairs murine squamous cell carcinoma development via modulation of antitumor immune responses

Squamous cell carcinoma (SCC) constitutes a microenvironment that could modulate the antitumor immune response. Also, tumor-infiltrating lymphocytes are believed to play complex regulatory roles in antitumor immunity against SCC. The presence of regulatory T cells (Tregs) has been associated with the suppression of tumor-reactive T cells. However, the underlying mechanism for this T cell dysfunction is not clear. We used a multistage model of SCC to examine the role of Treg cells during tumor development. 7,12-dimethylbenz[a]-anthracene/phorbol 12-myristate 13-acetate treatment and systemic depletion of Treg cells using an anti-CD25 monoclonal antibody (PC61) resulted in a decrease in the number and incidence of papilloma. Furthermore, CD25 depletion increased the proportion of CD8(+) and CD4(+) T cells that were isolated from tumor lesions. The levels of interleukin (IL)-1β, IL-10, IL-12, IL-13, interferon-γ, transforming growth factor-β and tumor necrosis factor-α, but not IL-17, were increased in the tumor microenvironment after Treg depletion. Therefore, our results indicated involvement of CD25(+) T cells in SCC development and in the suppression of the inflammatory immune response.

Combining bacterial-immunotherapy with therapeutic antibodies: a novel therapeutic concept

Immunotherapeutic strategies become more and more important for cancer treatment. Therapeutic monoclonal antibodies (mAbs) like Panitumumab binding and blocking the EGF-receptor are in routine clinical use for the treatment of colorectal carcinoma (CRC). Also, bacterial therapy proved beneficial for experimental treatment of different tumor entities. The latter has been attributed to an activation of the immune system. Here, we describe a combination of both immunotherapeutic approaches in order to develop a novel targeted therapy for CRC. The therapeutic mAbs Trastuzumab and Panitumumab were conjugated to heat-inactivated bacteria expressing protein A or protein G. The potential of the conjugates was tested in comparison to the single components both in vitro and in vivo using a panel of patient-derived CRC cell lines. Antitumoral effects observed in vitro were strictly dependent on the presence of bacteria. Generally, effects could be enhanced by the addition of human lymphocytes. Detailed analysis of effector cells in autologous and allogeneic long-term stimulated lymphocyte cultures revealed the predominance of NK-cell-like cytolytic effectors. Reactivity was observed both against CRC target cells but also against the NK cell target K562. Similarly, in a subsequent in vivo study we observed substantial tumor growth delay accompanied by an increase in circulating NK cells. Contrary to this, the monotherapy with mAb alone caused only marginal effects and the treatment with bacteria was comparable to the mock-treated control. These data demonstrate successful targeting of CRC by bacteria/mAb conjugates. This novel concept may be interesting for future clinical approaches. Additionally, it illustrates the effectiveness of NK cells for cancer immunotherapy.

Global gene expression changes in human urothelial cells exposed to low-level monomethylarsonous acid

Bladder cancer has been associated with chronic arsenic exposure. Monomethylarsonous acid [MMA(III)] is a metabolite of inorganic arsenic and has been shown to transform an immortalized urothelial cell line (UROtsa) at concentrations 20-fold less than arsenite. MMA(III) was used as a model arsenical to examine the mechanisms of arsenical-induced transformation of urothelium. A microarray analysis was performed to assess the transcriptional changes in UROtsa during the critical window of chronic 50nM MMA(III) exposure that leads to transformation at 3 months of exposure. The analysis revealed only minor changes in gene expression at 1 and 2 months of exposure, contrasting with substantial changes observed at 3 months of exposure. The gene expression changes at 3 months were analyzed showing distinct alterations in biological processes and pathways such as a response to oxidative stress, enhanced cell proliferation, anti-apoptosis, MAPK signaling, as well as inflammation. Twelve genes selected as markers of these particular biological processes were used to validate the microarray and these genes showed a time-dependent changes at 1 and 2 months of exposure, with the most substantial changes occurring at 3 months of exposure. These results indicate that there is a strong association between the acquired phenotypic changes that occur with chronic MMA(III) exposure and the observed gene expression patterns that are indicative of a malignant transformation. Although the substantial changes that occur at 3 months of exposure may be a consequence of transformation, there are common occurrences of altered biological processes between the first 2 months of exposure and the third, which may be pivotal in driving transformation.

In Vivo Modulation of Dendritic Cells by Engineered Materials: Towards New Cancer Vaccines

Therapeutic cancer vaccines are emerging as novel and potent approaches to treat cancer. These vaccines enhance the body's immune response to cancerous cells, and dendritic cells (DCs), an initiator of adaptive immunity, are a key cell type targeted by these strategies. Current DC-based cancer vaccines are based on ex vivo manipulation of the cells following their isolation from the patient, followed by reintroduction to the patient, but this approach has many limitations in practical cancer treatment. However, recent progress in materials science has allowed the design and fabrication of physically and chemically functionalized materials platforms that can specifically target DCs in the body. These materials, through their in vivo modulation of DCs, have tremendous potentials as new cancer therapies. Nanoparticles, which are several orders of magnitude smaller than DCs, can efficiently deliver antigen and danger signals to these cells through passive or active targeting. Three-dimensional biomaterials, with sizes several orders of magnitude larger than DCs, create microenvironments that allow the effective recruitment and programming of these cells, and can be used as local depots of nanoparticles targeting resident DCs. Both material strategies have shown potential in promoting antigen-specific T cell responses of magnitudes relevant to treating cancer.

Supernatants from lymphocytes stimulated with Bacillus Calmette-Guerin can modify the antigenicity of tumours and stimulate allogeneic T-cell responses

BACKGROUND

Reduced expression of class 1 human leucocyte antigens (HLA1) is often a mechanism by which tumours evade surveillance by the host immune system. This is often associated with an immune function that is unable to mount appropriate responses against disease, which can result in a state that favours carcinogenesis.

METHODS

In the current study, we have explored the effects of Bacillus Calmette-Guerin (BCG) on the cytokine output of leucocytes, which is a key determinant in generating antitumour action, and have also assessed the effect of these cytokine cocktails on HLA1 expression in solid tumour cell lines.

RESULTS

BCG potently activated a broad range of leucocytes, and also enhanced the production of cytokines that were Th(1)-predominant. Supernatants from BCG-treated leucocytes significantly increased the expression of HLA1 on the surface of cancer cell lines, which correlated with increased cytolytic T-cell activity. We also showed that the increased HLA1 expression was associated with activation of intracellular signalling pathways, which was triggered by the increases in the Th(1)-cytokines interferon-γ and tumour necrosis factor-α, as counteracting their effects negated the enhancement.

CONCLUSION

These studies reaffirm the role of BCG as a putative immunotherapy through their cytokine-modifying effects on leucocytes and their capacity to enhance tumour visibility.

Immunotherapy for urothelial carcinoma: current status and perspectives

Intravesical instillation of bacillus Calmette Guérin (BCG) for the treatment of urothelial carcinoma (UC) of the bladder is based on the BCG-induced immune response, which eradicates and prevents bladder cancer. The results of recent studies have suggested that not only major histocompatibility complex (MHC)-nonrestricted immune cells such as natural killer cells, macrophages, neutrophils, etc., but also MHC-restricted CD8⁺ T cells play an important role and are one of the main effectors in this therapy. Better understanding of the mechanism of BCG immunotherapy supports the idea that active immunotherapy through its augmented T cell response can have great potential for the treatment of advanced UC. In this review, progress in immunotherapy for UC is discussed based on data from basic, translational and clinical studies. We also review the escape mechanism of cancer cells from the immune system, and down-regulation of MHC class I molecules.