Defective antigen presentation resulting from impaired expression of costimulatory molecules in breast cancer

Pharmacological properties, therapeutic potential, and legal status of Cannabis sativa L.: An overview

Marijuana, or Cannabis sativa L., is a common psychoactive plant used for both recreational and medicinal purposes. In many countries, cannabis-based medicines have been legalized under certain conditions because of their immense prospects in medicinal applications. With a comprehensive insight into the prospects and challenges associated with the pharmacological use and global trade of C. sativa, this mini-review focuses on the medicinal importance of the plant and its legal status worldwide; the pharmacological compounds and its therapeutic potential along with the underlying public health concerns and future perspective are herein discussed. The existence of major compounds including Δ⁹ -tetrahydrocannabinol (Δ⁹ -THC), cannabidiol, cannabinol, and cannabichromene contributes to the medicinal effects of the cannabis plant. These compounds are also involved in the treatment of various types of cancer, epilepsy, and Parkinson's disease displaying several mechanisms of action. Cannabis sativa is a plant with significant pharmacological potential. However, several aspects of the plant need an in-depth understanding of the drug mechanism and its interaction with other drugs. Only after addressing these health concerns, legalization of cannabis could be utilized to its full potential as a future medicine.

Biomechanics of T Cell Dysfunctions in Chronic Diseases

Understanding the mechanisms behind T cell dysfunctions during chronic diseases is critical in developing effective immunotherapies. As demonstrated by several animal models and human studies, T cell dysfunctions are induced during chronic diseases, spanning from infections to cancer. Although factors governing the onset and the extent of the functional impairment of T cells can differ during infections and cancer, most dysfunctional phenotypes share common phenotypic traits in their immune receptor and biophysical landscape. Through the latest developments in biophysical techniques applied to explore cell membrane and receptor-ligand dynamics, we are able to dissect and gain further insights into the driving mechanisms behind T cell dysfunctions. These insights may prove useful in developing immunotherapies aimed at reinvigorating our immune system to fight off infections and malignancies more effectively. The recent success with checkpoint inhibitors in treating cancer opens new avenues to develop more effective, targeted immunotherapies. Here, we highlight the studies focused on the transformation of the biophysical landscape during infections and cancer, and how T cell biomechanics shaped the immunopathology associated with chronic diseases.

Senescent T cells within suppressive tumor microenvironments: emerging target for tumor immunotherapy

The functional state of the preexisting T cells in the tumor microenvironment is a key determinant for effective antitumor immunity and immunotherapy. Increasing evidence suggests that immunosenescence is an important state of T cell dysfunction that is distinct from exhaustion, a key strategy used by malignant tumors to evade immune surveillance and sustain the suppressive tumor microenvironment. Here, we discuss the phenotypic and functional characteristics of senescent T cells and their role in human cancers. We also explore the possible mechanisms and signaling pathways responsible for induction of T cell senescence by malignant tumors, and then discuss potential strategies to prevent and/or reverse senescence in tumor-specific T cells. A better understanding of these critical issues should provide novel strategies to enhance cancer immunotherapy.

Exhaustion and senescence: two crucial dysfunctional states of T cells in the tumor microenvironment

The failure of a massive influx of tumor-infiltrating T lymphocytes to eradicate tumor cells in the tumor microenvironment is mainly due to the dysfunction of T cells hyporesponsive to tumors. T-cell exhaustion and senescence induced by malignant tumors are two important dysfunctional states that coexist in cancer patients, hindering effective antitumor immunity and immunotherapy and sustaining the suppressive tumor microenvironment. Although exhausted and senescent T cells share a similar dysfunctional role in antitumor immunity, they are distinctly different in terms of generation, development, and metabolic and molecular regulation during tumor progression. Here, we discuss the unique phenotypic and functional characteristics of these two types of dysfunctional T cells and their roles in tumor development and progression. In addition, we further discuss the potential molecular and metabolic signaling pathways responsible for the control of T-cell exhaustion and senescence in the suppressive tumor microenvironment. Understanding these critical and fundamental features should facilitate rethinking the unresponsiveness to current immunotherapies in clinical patients and lead to further development of novel and effective strategies that target different types of dysfunctional T cells to enhance cancer immunotherapy.

Preclinical and Clinical Assessment of Cannabinoids as Anti-Cancer Agents

Cancer is the second leading cause of death in the United States with 1.7 million new cases estimated to be diagnosed in 2016. This disease remains a formidable clinical challenge and represents a substantial financial burden to the US health care system. Therefore, research and development of novel therapeutics for the treatment of cancer is of high priority. Cannabinoids and their derivatives have been utilized for their medicinal and therapeutic properties throughout history. Cannabinoid activity is regulated by the endocannabinoid system (ECS), which is comprised of cannabinoid receptors, transporters, and enzymes involved in cannabinoid synthesis and breakdown. More recently, cannabinoids have gained special attention for their role in cancer cell proliferation and death. However, many studies investigated these effects using in vitro models which may not adequately mimic tumor growth and metastasis. As such, this article aims to review study results which evaluated effects of cannabinoids from plant, synthetic and endogenous origins on cancer development in preclinical animal models and to examine the current standing of cannabinoids that are being tested in human cancer patients.

TLR8 signaling enhances tumor immunity by preventing tumor-induced T-cell senescence

Accumulating evidence suggests the immunosuppressive microenvironments created by malignant tumors represent a major obstacle for effective anti-tumor immunity. A better understanding of the suppressive mechanisms mediated by tumor microenvironments and the development of strategies to reverse the immune suppression are major challenges for the success of tumor immunotherapy. Here, we report that human tumor cells can induce senescence in naïve/effector T cells, exhibiting potent suppressive function in vitro and in vivo. We further show that tumor-derived endogenous cyclic adenosine monophosphate (cAMP) is responsible for the induction of T-cell senescence. Importantly, activation of TLR8 signaling in tumor cells can block the induction and reverse the suppression of senescent naïve and tumor-specific T cells in vitro and in vivo, resulting in enhanced anti-tumor immunity. These studies identify a novel mechanism of human tumor-mediated immune suppression and provide a new strategy to reverse tumor immunosuppressive effects for tumor immunotherapy.

E2F1 renders prostate cancer cell resistant to ICAM-1 mediated antitumor immunity by NF-κB modulation

Background

E2F1 is the gatekeeper of the cell cycle controlling an analogous balance between proliferation and cell death. E2F1 expression is elevated in advanced prostate cancer. However, it is still unclear that the roles and mechanisms of E2F1 on prostate cancers.

Methods

Targeted knockdown by interferon RNA was applied on two prostate cancer and Hela cell lines to examine the inverse correlation expression of E2F1 and ICAM-1. ICAM-1 promoter reporter and ChIP assays were used for analysis of the molecular basis of transcriptional regulation of E2F1 on ICAM-1. Co-IP assays were employed for testing the protein interaction between E2F1 and NF-κB. Tumor xenograft mice model with E2F1 and ICAM-1-knockdown prostate cancer cells were used to investigate the effects of E2F1 and ICAM-1 on antitumor immunity.

Results

E2F1 knockdown by a specific short hairpin RNA increased gene transcription and protein expression of ICAM-1. By using wild type and a series of mutant ICAM-1 promoter luciferase constructs, the NF-κB binding sites were found to be important for E2F1 regulation of ICAM-1 promoter. Targeted knockdown of E2F1 did not affect expression and phosphorylation of NF-κB and IκBα, but facilitated NF-κB binding to the ICAM-1 promoter, subsequently induced ICAM-1 transcription and production in prostate carcinoma cells. Furthermore, knockdown of E2F1 inhibited tumor growth of prostate cancer in vivo through increasing the susceptibility of tumor cells to ICAM-1-mediated anti-tumor immunity including enhancement of monocyte adhesion, leucocytes infiltration, as well as cytotoxicity against tumor cells.

Conclusions

E2F1 knockdown inhibited prostate tumor growth in vitro and in vivo through sensitizing tumor cells to ICAM-1 mediated anti-immunity by NF-κB modulation, highlighting the potential of E2F1 as a therapeutic target.

Detecting disease associated modules and prioritizing active genes based on high throughput data

BACKGROUND

The accumulation of high-throughput data greatly promotes computational investigation of gene function in the context of complex biological systems. However, a biological function is not simply controlled by an individual gene since genes function in a cooperative manner to achieve biological processes. In the study of human diseases, rather than to discover disease related genes, identifying disease associated pathways and modules becomes an essential problem in the field of systems biology.

RESULTS

In this paper, we propose a novel method to detect disease related gene modules or dysfunctional pathways based on global characteristics of interactome coupled with gene expression data. Specifically, we exploit interacting relationships between genes to define a gene's active score function based on the kernel trick, which can represent nonlinear effects of gene cooperativity. Then, modules or pathways are inferred based on the active scores evaluated by the support vector regression in a global and integrative manner. The efficiency and robustness of the proposed method are comprehensively validated by using both simulated and real data with the comparison to existing methods.

CONCLUSIONS

By applying the proposed method to two cancer related problems, i.e. breast cancer and prostate cancer, we successfully identified active modules or dysfunctional pathways related to these two types of cancers with literature confirmed evidences. We show that this network-based method is highly efficient and can be applied to a large-scale problem especially for human disease related modules or pathway extraction. Moreover, this method can also be used for prioritizing genes associated with a specific phenotype or disease.

Intercellular adhesion molecule-1 genetic markers (+241G/A and +469A/G) in Iranian women with breast cancer

Breast cancer is the most common cancer among women, the second-most leading cause of women's death after lung cancer. ICAM-1 is a cell adhesion molecule that belongs to the Ig-superfamily, with a glycoprotein structure playing a key role in leukocyte recruitment into inflammatory sites, as well as in leukocyte activation and effector function. Proteolytic cleavage of ICAM-1 results in the formation of a soluble form, sICAM-1, which is present in low-serum levels in healthy individuals but becomes elevated in inflammatory and malignant conditions. The ICAM1 gene is located on chromosome 19 and contains two well-known single-nucleotide polymorphisms (SNP) of +241G/A (G241R) and +469A/G (K469E). In this study, the frequencies of the two polymorphisms were investigated in breast cancer patients and healthy individuals. For G241R, we selected 276 breast cancer patients and 235 healthy sex-matched controls, and for K469E, 264 patients and 200 healthy sex-matched controls were chosen. The results of this study show that the frequency of the GA genotype was significantly higher in breast cancer patients in comparison to the control group (P = 0.007). In addition, the frequency of the R allele was significantly higher in breast cancer patients compared to controls (P = 0.008). However, both the genotype and allele frequency of K469E did not differ significantly between patients and controls. A significant difference was observed in the frequency of genotype combination A/G (+241 G/A and +469 A/G, respectively) between patients and controls (6.2 vs. 2.2%; (*)P = 0.007). These findings indicate that individuals carrying the A allele of the ICAM1 gene as well as the A/G haplotype may have a higher risk of developing breast cancer.

Induction of maturation and activation of human dendritic cells: a mechanism underlying the beneficial effect of Viscum album as complimentary therapy in cancer

BACKGROUND

Viscum album (VA) preparations have been used as a complimentary therapy in cancer. In addition to their cytotoxic properties, they have also been shown to have immunostimulatory properties. In the present study, we examine the hypothesis that the VA preparations induce activation of human DC that facilitates effective tumor regression.

METHODS

Four day old monocyte-derived immature DCs were treated with VA Qu Spez at 5, 10 and 15 microg/ml for 48 hrs. The expression of surface molecules was analyzed by flow cytometry. The ability of Qu Spez-educated DC to stimulate T cells was analyzed by allogeneic mixed lymphocyte reaction and activation of Melan-A/MART-1-specific M77-80 CD8+T cells. Cytokines in cell free culture supernatant was analyzed by cytokine bead array assay.

RESULTS

VA Qu Spez stimulated DCs presented with increased expression of antigen presenting molecule HLA-DR and of co-stimulatory molecules CD40, CD80 and CD86. The VA Qu Spez also induced the secretion of inflammatory cytokines IL-6 and IL-8. Further, Qu Spez-educated DC stimulated CD4+T cells in a allogeneic mixed lymphocyte reaction and activated melanoma antigen Melan-A/MART-1-specific M77-80 CD8+T cells as evidenced by increased secretion of TNF-alpha and IFNgamma.

CONCLUSION

The VA preparations stimulate the maturation and activation of human DCs, which may facilitate anti-tumoral immune responses. These results should assist in understanding the immunostimulatory properties of VA preparations and improving the therapeutic strategies.

Humoral immune responses to MUC1 in women with a BRCA1 or BRCA2 mutation

INTRODUCTION

Breast cancer patients with early disease and a natural humoral response to MUC1 have a favourable prognosis, suggesting a possible role of MUC1 antibodies (ab) in controlling haematogenous tumour dissemination and outgrowth. The aim of the study was to evaluate humoral immune responses to MUC1 in women at hereditary high risk of breast cancer to investigate whether this immune response could play a role in the prevention of disease.

MATERIALS AND METHODS

CA15.3 (U/mL), and IgG and IgM ab to MUC1 (arbitrary units per mL, Arb-U/mL) were measured in serum samples obtained from 422 women at hereditary high risk of breast/ovarian cancer, of whom 127 BRCA1/2 carriers, attending the Familial Cancer Clinic of the VU University Medical Centre, and from 370 age-matched healthy controls. Serum samples obtained from women who developed breast cancer (N=12) or breast cancer recurrence (N=17), and from women who underwent prophylactic mastectomy (N=12) and had no breast lesions were also tested.

RESULTS

CA15.3 ranked significantly higher in mutation carriers than in controls (P=0.03). MUC1 IgG ab levels ranked significantly lower in BRCA1/2 mutation carriers than in controls (P=0.003). MUC1 IgG levels were not significantly different (P=0.53) between women who developed primary breast cancer (median 0.72Arb-U/ml, range 0.52-2.44Arb-U/ml) and women who underwent prophylactic mastectomy and had no breast lesions (median 1.04Arb-U/ml, range 0.43-2.88Arb-U/ml).

CONCLUSION

Serum levels of natural IgG ab to MUC1 are lower in BRCA1/2 mutation carriers than in healthy controls. Furthermore, in contrast to previous results in women with sporadic breast cancer, no elevated MUC1 IgG ab were seen in women at hereditary high risk who developed breast cancer. Prophylactic immunotherapy with MUC1 substrates may be a strategy to reduce the risk of breast cancer in BRCA1/2 mutation carriers, strengthening tumour immune surveillance.

Expression of the costimulatory molecule CD86, but not CD80, in keratinocytes of normal cervical epithelium and human papillomavirus-16 positive low squamous intraepithelial lesions

Keratinocytes have been traditionally considered as nonprofessional antigen presenting cells, since multipassaged cells from skin biopsies of healthy individuals do not constitutively express major histocompatibility complex (MHC) class II or costimulatory molecules, but can be induced to do so after exposure to interferon-gamma. In normal and human papillomavirus (HPV)-infected cervical epithelium, keratinocytes are affected by a variety of soluble mediators that could modulate the expression of molecules including costimulatory proteins; however, the presence of these molecules within the cervix has been poorly studied. Therefore, our aim was to further explore the presence of costimulatory molecules on normal cervical epithelium and HPV-16 positive low squamous intraepithelial lesions (LSIL). We found in situ CD86 (but not CD80) displayed on the surface of normal keratinocytes from the spinous layer of human cervical epithelium. The presence of the protein and its messenger RNA level (evaluated by in situ hybridization) was diminished in HPV-16 positive LSILs. Although downregulation of costimulatory molecules is frequently related to cytokines expression, we did not observe differences in the presence of interleukin-10, the main cytokine that inhibits CD86 expression. Expression of CD86 on keratinocytes from normal cervical epithelium could indicate the potentiality of these cells to activate cytotoxic T cells, while the shut-off of this molecule in HPV-16 positive lesions could be a mechanism for evading host immune surveillance, resulting in the persistent HPV infection and probable progression of cervical lesions.

Preliminary evidence that the allogeneic response might trigger antitumour immunity in patients with advanced prostate cancer

OBJECTIVE

To explore the possibility that allogeneic responses might, by chance, encompass cross-reactive T cell clones specific for neo-antigenic tumour determinants, and thereby activate antitumour immunity; such cross-reactions are well documented for antiviral immunity, and genetic instability in developing cancers generates many neo-antigenic determinants as potential targets for immune responses, but the biology inevitably favours tumour progression.

PATIENTS AND METHODS

Fourteen patients with hormone-refractory prostate cancer received full-thickness skin allografts from different, unrelated donors (fellow patients) until each had received six grafts. Serum prostate-specific antigen (PSA) level was used as a surrogate for tumour mass.

RESULTS

One patient had a remarkable decline in PSA level, with levels at 1 year lower than before grafting. A second patient had stable PSA levels for almost 2 years. A third patient had stable PSA levels for 10-12 months before they resumed an exponential rise. Of four patients with PSA levels of > 10 ng/mL, three required surgery or radiotherapy for obstructive symptoms during or shortly after grafting.

CONCLUSION

Transplant rejection involves mechanistically atypical T cell recognition of allogeneic major histocompatibility complex antigens, with massive polyclonal T cell activation. This unique aspect of T cell biology might represent a novel approach for initiating cross-reactive antitumour responses.

Diminished neo-antigen response to keyhole limpet hemocyanin (KLH) vaccines in patients after treatment with chemotherapy or hematopoietic cell transplantation

Relapse is the most common cause of treatment failure for advanced cancer, even those treated with autologous hematopoietic cell transplantation (HCT). Effective tumor-specific immunotherapy may decrease relapse, however, this will fail if the immune system is unable to respond. We developed a strategy to test immune responses with a single injection of the bona fide neo-antigen KLH. The model was first tested in 37 normal volunteers using three KLH vaccines: Intracel KLH, Biosyn KLH, and Biosyn KLH + adjuvant. Despite finding the immunogenic epitope conserved in both products, intact Intracel KLH induced a better response compared to a purified 350/390 kDA subunit of KLH contained in the Biosyn KLH product. Addition of a synthetic oil adjuvant (Montanide ISA51) restored the response to a single injection of Biosyn KLH. A quantitative readout measured by a KLH-specific cellular and humoral response with isotype switching 1 month after KLH vaccination was established. To test the integrity of the adaptive immune response in cancer patients, we vaccinated 14 patients post-HCT and 19 patients with advanced cancer with KLH vaccines that elicited a 100% response rate in normal volunteers. In marked contrast to normal subjects, both responses were significantly impaired up to 16 months after autologous HCT with an intermediate response in advanced cancer patients. KLH vaccines are safe and require only a single injection to test neo-antigen responses providing an optimal platform for definitive testing of strategies to improve diminished immune recovery after chemotherapy or post-HCT.

Role of ICAM1 in invasion of human breast cancer cells

We identified previously a region on chromosome 19p13.2 spanning the genes encoding the intercellular adhesion molecules (ICAM), ICAM1, ICAM4 and ICAM5 as a breast cancer susceptibility locus. Genetic variants in this region were also associated with indicators of disease severity, including higher rates of metastases to other organs. Based on this association, we set out to explore the role of ICAM1 in proliferation and invasion of human breast cancer cells. We observed that ICAM1 downregulation at the mRNA and protein levels led to a strong suppression of human breast cell invasion through a matrigel matrix. Under the same conditions, no significant effect on cell proliferation in vitro was seen. Incubation of cells with an antibody against ICAM1 blocked invasion of the highly metastatic MDA-MB-435 cell line in a dose-dependent manner without affecting cell migration. We also demonstrated that the level of ICAM1 protein expression on the cell surface positively correlated with metastatic potential of five human breast cancer cell lines and that ICAM1 mRNA levels were elevated in breast tumor compared with adjacent normal tissue. These results corroborate our previous genetic finding that variations in the ICAM region are associated with the occurrence of metastases and establish a causal role of ICAM1 in invasion of metastatic human breast carcinoma cell lines.

Hematopoietic stem cells mobilization and immune response in tumor-bearing mice

INTRODUCTION

Malignant diseases are known to modulate the number and function of myeloid, erythroid, and lymphoid cells. Since these cells are derived from hematopoietic stem cells (HSC), it is not clear if the observed effects of cancer on such cells are direct or indirect via stem cells. The purpose of this study was to evaluate the effect of breast cancer upon the levels and activity of peripheral blood hematopoietic stem cells.

MATERIALS AND METHODS

Four weeks following the establishment of 4T1 breast cancers in BALB/c mice, the animals were killed, blood and spleen harvested, and processed for light density mononuclear cells. Colony forming unit in culture assay was used to determine the activity of HSCs. Flow cytometry was used to determine the levels of lineage negative HSCs expressing c-kit and Sca-1 antigen (Lin c-kitSca-1). Mitogenic, cytotoxic and ELISPOT assays were used to evaluate functional properties of cells. Plasma cytokine levels were determined with ELISA assay.

RESULTS

In tumor-bearing mice, there was a 2- and 4-fold increase in the levels and proliferative capacity of HSCs, respectively, compared with controls. Contemporaneously, there was a 13-fold increase in plasma G-CSF in tumor-bearing animals compared with controls (0.225 ng/ml versus 3.0 ng/ml). Furthermore, the number of interferon gamma-secreting cells was significantly increased in tumor-bearing animals. Concurrently, cytotoxic activity of NK cells was significantly increased in tumor-bearing animals as compared with controls (22.4 +/- 10.6 versus 10.3 +/- 2.95; P < 0.05).

SUMMARY

These results suggest that (1) breast cancer mobilizes hematopoietic stem cells in mice presumably through G-CSF production, and (2) that such cancer-mobilized stem cells give rise to immune cell lineages which are functionally hyperactive in their cytotoxic activities. Such cells could be expected to have appreciable therapeutic benefit in terms of cancer cell cytotoxic activity when used as part of stem cell transplantation therapy in cancer patients.

Immunobiological Characterization of N-Nitrosomethylurea-Induced Rat Breast Carcinomas: Tumoral IL-10 Expression as a Possible Immune Escape Mechanism

Improvement of immunotherapy-based protocols in cancer requires a better understanding of tumor microenvironment and tumor-host interaction. Stromal and immune cells and molecules such as cytokines, chemokines, growth factors and metalloproteases mediate tumor-host interaction determining, at least in part, tumor development. In the present study, we used an immunohistochemical approach to explore leukocyte sub-populations, cytokine profiles and costimulatory molecule expression in rat N -Nitrosomethylurea (NMU)-induced breast tumors. Our results show a strong leukocyte infiltration mainly composed of macrophages and TCR alphabeta positive T cells. We observed a weak expression of costimulatory molecules (CD80, CD86) and an absence of inflammatory cytokines (IFNgamma, TNFalpha, IP-10) and lymphocyte activation markers (CD25). Interestingly, this immunosuppressed status could be a consequence of IL-10 expression by malignant cells, as demonstrated by immunohistology and western blot analysis, which seems to be an early event during mammary carcinogenesis. Analysis of a cell line derived from an NMU-induced rat breast tumor showed that this cell line also expresses IL-10. This study shows that the NMU model of rat breast cancer could be used to evaluate different immune based therapies as well as to study the role of IL-10 in breast cancer. Furthermore, this rat breast cancer model shows an immunohistological profile similar to that found in human cancer and the fact that it develops like spontaneously arising malignancies make it interesting as a cancer model in immunobiology.

Defect of tumour necrosis factor-alpha (TNF-alpha) production and TNF-alpha-induced ICAM-1-expression in BRCA1 mutations carriers

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) is a potent cytokine secreted primarily by activated cells from the monocyte/macrophage lineage which exhibits various antitumoral effects including the induction of apoptosis, necrosis, activation of lytic effector cells as well as upregulation of the expression of intercellular adhesion molecule-1 (ICAM-1) which is of decisive importance in the interaction with lymphokine activated killer cells. Previous studies from our laboratory have indicated impaired production of TNF-alpha by monocytes as well as decreased expression of ICAM-1 on monocytes derived from patients with various stages of breast cancer.

METHODS

In the present experiments, we have assessed spontaneous as well as lipopolysaccharide (LPS)-induced production of TNF-alpha by as well as expression of ICAM-1 on monocytes derived from healthy females with germline mutations of BRCA1 and from healthy age-matched control females.

RESULTS

We report that monocytes derived from healthy women with various germline mutations of BRCA1 had significantly decreased spontaneous (p = 0.03) and LPS-induced (p < 0.001) production of TNF-alpha, as compared to monocytes derived from healthy age-matched control females. In contrast, no difference in LPS- or TNF-alpha-induced production of interleukin-6 was found. Whereas unstimulated monocytes derived from healthy women with germline mutations of BRCA1 and from healthy control women had similar expression of ICAM-1, stimulation with cytokines TNF-alpha and/or interleukin-1 led to a significant increase of ICAM-1 expression on monocytes derived from control females only, but not from BRCA1 germline mutation carriers (p < 0.001).

CONCLUSION

We conclude that the presence of germline mutations of BRCA1 was associated with a selective deficiency in spontaneous and LPS-induced production of TNF-alpha and of TNF-alpha-induced ICAM-1 expression on peripheral blood monocytes.

Human regional lymph nodes draining cancer exhibit a profound dendritic cell depletion as comparing to those from patients without malignancies

Dendritic cells (DCs) are bone-marrow derived 'professional' antigen presenting cells (APC). They are considered as the most potent APC able to induce primary immune responses. DC efficiently capture and process proteic and non-proteic antigens. They are widely distributed throughout the body and occupy sentinel positions such as epithelia. Establishment of an immune response against cancer may depend of the capacity of DCs to transfer (to capture, to process and to present) tumor antigens into regional lymph nodes where they can induce a specific response leading to tumor rejection. Because host 'professional' DCs are one of the most important elements in the induction of specific anti-tumor responses and lymph nodes are the places where the immune response takes place, we investigated the densities of DCs within regional metastasis-free lymph nodes from 47 patients with different malignant epithelial tumors as comparing with lymph nodes from 11 patients without malignancies using an immunohistochemistry method with anti-S100 protein, CD86 and CD1a antibodies. By means of morphometric analysis, we observed that S100+ and CD1a+ DCs densities in regional lymph nodes from cancer patients were significatively decreased as compared with control lymph nodes (P<0.0001 and 0.003, respectively). S100+ DCs and CD86+ DCs densities in lymph nodes draining cancer were similar. Taken together, these data indicated that lymph nodes draining cancer had significantly less CD1a+ DCs than S100+ and possibly CD86+ DCs. These findings may represent another mechanism by which tumors evade the immune recognition.

Dysfunctional and short-lived subsets in monocyte-derived dendritic cells from patients with advanced cancer

Dendritic cells (DCs) are antigen-presenting cells specialized for the induction of the primary T-cell response. Tumor immunotherapy using DCs loaded with tumor antigens is under way for patients with several types of advanced malignancies. In this study, DC-like cells (Mo-DCs) were generated from peripheral blood monocytes with granulocyte-macrophage colony-stimulating factor and interleukin-4. The antigen-presenting abilities, including capture of apoptotic tumor cells, IL-12 secretion, expression of antigen-presentation-related molecules (HLA-ABC, HLA-DR, and CD80), and mixed leukocyte reaction, of Mo-DCs from 37 patients with advanced cancer (pMo-DCs) were compared to those of 20 healthy volunteers (hMo-DCs). Seven days after the initial culture, no significant difference was found in either the number or the size of Mo-DC-forming colonies between the two groups. However, most of the antigen-presenting abilities of pMo-DCs were weaker than those of hMo-DCs on day 7. On day 14, both number and size of colonies were significantly decreased in pMo-DCs but not in hMo-DCs. Interestingly, the antigen-presenting abilities of the remaining pMo-DCs gradually strengthened with time and by day 14 no significant difference was observed between pMo-DCs and hMo-DCs. These results indicate that pMo-DCs contain dysfunctional and short-lived Mo-DC subsets.

Down-regulation of the CD3-zeta chain in sentinel node biopsies from breast cancer patients

BACKGROUND

In several neoplastic diseases, immunosuppression has been shown to correlate with disease stage, progression, and outcome. As the prognosis for metastatic breast cancer is still pessimistic, additional strategies are being sought to improve survival. Local immunosuppression in sentinel node biopsies from 24 evaluable breast cancer patients was studied as a possible way of selecting patients for immunotherapy.

METHOD

Sentinel node biopsy was performed in 24 out of 25 women operated on for primary breast cancer (one was not evaluable). Specimens were snap-frozen and double-stained for the zeta-chain of the T-cell receptor. The degree of down-regulation of the zeta-chain was evaluated in three different lymph-node areas: primary follicles, secondary follicles, and paracortex.

RESULTS

Down-regulation of varying degrees was noted in all 24 sentinel node biopsies. A high degree of down-regulation (more than 50% of T-cells not expressing zeta-chain) was seen in the primary follicles in six patients (25%), in the secondary follicles in 13 patients (72%), and in the paracortex in 19 patients (79%).

CONCLUSION

Local down-regulation of an immune function parameter was seen in sentinel node biopsies from breast cancer patients. In addition to possible prognostic implications, the sentinel node might be an appropriate location for detecting early-stage immunological down-regulation, which might open a possibility of selecting patients who could benefit from immunotherapy.

Analysis of the gene-expression profile regarding the progression of human gastric carcinoma

BACKGROUND

Tumor tissue consists of a variable mixture of tumor and host-cell populations. Recent developments in laser microdissection (LMD) and cDNA microarray analysis have encouraged us to study the differential gene expression profiles among normal cells, primary carcinoma cells, and metastatic carcinoma cells in cases of gastric carcinoma.

METHODS

Total RNA was extracted from the cells obtained by means of LMD from the primary carcinoma, the corresponding gastric epithelium, and the lymph node metastasis in 5 cases of primary gastric carcinoma. RNA was amplified by the T7-based amplification system to be applied to a cDNA microarray. Thereafter, the differentially expressed genes among the 3 populations were evaluated.

RESULTS

cDNA samples for microarray studies were successfully obtained from each cell population of 5 cases. The cDNA microarray demonstrated that several interesting genes, such as cell-cycle regulators and growth factors, were overexpressed in the metastatic cells compared with in the primary carcinoma cells. Oncogenes and cell-adhesion molecules were more overexpressed in the primary carcinoma cells than in the normal cells. On the other hand, caspase 8 and cadherin were more suppressed in the primary carcinoma cells than in the normal cells. Interestingly, among the matrix metalloproteinase family, only MMP7 was identified as a differentially overexpressed gene in both the primary carcinoma and the metastatic cells in comparison with the normal cells.

CONCLUSIONS

This study demonstrated that the combined use of LMD, T7-based amplification, and a cDNA microarray enabled us to identify genes directly associated with each population of tumor tissue. The method will open up new possibilities for the precise gene analysis of tumor progression and metastasis.