Involvement of granzyme B and perforin in suppressing nodal metastasis of cancer cells in breast and lung cancers

A peptides-based biosensor with target-triggered charge-switchable property for simple and sensitive detection of Granzyme B

Granzyme B (GrB) is a serine protease released by natural killer cells and cytotoxic T lymphocytes during immune responses, which not only plays a role in tumor diagnosis but also provides valuable guidance during tumor treatment. In this work, we have designed a charge-switching peptide to fabricate an electrochemical biosensor for quantitative analysis of GrB. Specifically, the designed zwitterionic peptide is in an electrically neutral state before activation, and a door lock structure (proline) is constructed by utilizing the selectivity of carboxypeptidase A (CPA) to the carboxy-terminus of the peptide chain. The door lock is opened when the target is present, allowing CPA to hydrolyze the peptide. At this time, the peptide will convert from neutral to positive, triggering the assembly of a positively charged peptide layer on the electrode surface, resulting in a signal change. Studies have shown that the biosensor has good analytical performance, with a detection range of 0.01 pM-8 pM and a detection limit as low as 3.5 fM. Moreover, the developed biosensor has been effectively applied to the analysis of clinical samples, demonstrating its ability to monitor tumor progression and treatment with clinical applications.

Granzyme B Expression in the Tumor Microenvironment as a Prognostic Biomarker for Patients with Triple-Negative Breast Cancer

Tumor-infiltrating lymphocytes in the tumor microenvironment are important in the treatment of triple-negative breast cancer (TNBC). Cytotoxic T cells produce cytokines and cytotoxic factors, such as perforin and granzyme, which induce apoptosis by damaging target cells. To identify biomarkers of these cells, we investigated granzyme B (GZMB) in the tumor microenvironment as a biomarker of treatment response and prognosis in 230 patients with primary TNBC who underwent surgery without preoperative chemotherapy between January 2004 and December 2014. Programmed cell death ligand 1 (PD-L1) positivity was defined as a composite positive score ≥10 based on the PD-L1 immunostaining of tumor cells and immune cells. GZMB-high was defined as positivity in ≥1% of tumor-infiltrating lymphocytes (TILs). Among the 230 TNBC patients, 117 (50.9%) had CD8-positive infiltrating tumors. In the PD-L1-positive group, a Kaplan-Meier analysis showed that GZMB-high TNBC patients had better recurrence-free survival (RFS) and overall survival (OS) than GZMB-low patients and that OS was significantly longer (RFS: p = 0.0220, OS: p = 0.0254). A multivariate analysis also showed significantly better OS in PD-L1- and GZMB-high patients (hazard ratio: 0.25 (95% IC: 0.07-0.88), p = 0.03). Our findings indicate that GZMB is a useful prognostic biomarker in PD-L1-positive TNBC patients.

CircSTK3 drives the metastasis of colorectal cancer by regulating epithelial-mesenchymal transition

Circular RNAs (circRNAs) play crucial roles in malignancies. We aimed to delineate the functions and clinical importance of dysregulated circRNAs in colorectal cancer (CRC). We determined the circRNA expression profile from five CRC and paired adjacent normal tissues using circRNA microarray. We found that a novel circRNA, hsa_circ_0004592 (named circSTK3), was significantly upregulated in CRC tissues and correlated with decreased survival. Loss- and gain-of-function assays revealed that circSTK3 promoted the migration and invasion but not proliferation of cells. Whole genome expression microarray identified potential downstream targets and the regulatory networks of circSTK3; Gene Ontology analysis confirmed circSTK3 involvement in the CRC metastasis phenotype. Abnormal circSTK3 expression affected a subset of genes associated with CRC metastasis and triggered epithelial-mesenchymal transition programming, maintaining a tumor-promoting signature. Moreover, circSTK3 was transcriptionally regulated by CTCF. These findings reveal the functional and prognostic roles of circSTK3 and expose circRNAs as key players in metastasis.

Immunotherapeutic targets in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most common types of cancer in the world and has a 5-year survival rate of ~20%. Immunotherapies have shown promising results leading to durable responses, however, they are only effective for a subset of patients. To determine the best therapeutic approach, a thorough and in-depth profiling of the tumour microenvironment (TME) is required. The TME is a complex network of cell types that form an interconnected network, promoting tumour cell initiation, growth and dissemination. The stroma, immune cells and endothelial cells that comprise the TME generate a plethora of cytotoxic or cytoprotective signalling pathways. In this review, we discuss immunotherapeutic targets in NSCLC tumours and how the TME may influence patients' response to immunotherapy.

Granzymes expression patterns predict immunotherapy response and identify the heterogeneity of CD8+ T cell subsets

BACKGROUND

Recent studies illustrated the effects of granzymes (GZMs) gene alterations on immunotherapy response of cancer patients. Thus, we aimed to systematically analyze the expression and prognostic value of GZMs for immunotherapy in different cancers, and identified heterogeneity of the GZMs expression-based CD8+ T cell subsets.

METHODS

First, we analyzed GZMs expression and prognostic value at pan-cancer level. Meanwhile, we established a GZMs score by using the single-sample gene set enrichment analysis (ssGSEA) algorithm to calculate the enrichment scores (ES) based on a gene set of five GZMs. The potential value of GZMs score for predicting survival and immunotherapy response was evaluated using the tumor immune dysfunction and exclusion (TIDE) and immunophenoscore (IPS) algorithm, and we validated it in immunotherapy cohorts. CellChat, scMetabolism, and SCENIC R packages were used for intercellular communication networks, quantifying metabolism activity, and regulatory network reconstruction, respectively.

RESULTS

The GZMs score was significantly associated with IPS, TIDE score. Patients with high GZMs score tended to have higher objective response rates of immunotherapy in melanoma and urothelial carcinoma. GZMs expression-based CD8+ T cell subsets presented heterogeneity in functions, metabolism, intercellular communications, and the tissue-resident memory programs in lung adenocarcinoma (LUAD). The transcription factors RUNX3 and ETS1, which may regulate the expression of GZMs, was found to be positively correlated with the tissue-resident memory T cells-related marker genes.

CONCLUSIONS

The higher GZMs score may indicate better response and overall survival (OS) outcome for immunotherapy in melanoma and urothelial carcinoma but worse OS in renal cell carcinoma (RCC). The GZMs score is a potential prognostic biomarker of diverse cancers. RUNX3 and ETS1 may be the potential targets to regulate the infiltration of GZMs expression-based CD8+ T cell subsets and affect the tissue-resident memory programs in LUAD, which may affect the prognosis of LUAD patients and the response to immunotherapy.

Breast cancers co-opt normal mechanisms of tolerance to promote immune evasion and metastasis

Normal developmental processes, such as those seen during embryonic development and postpartum mammary gland involution, can be reactivated by cancer cells to promote immune suppression, tumor growth, and metastatic spread. In mammalian embryos, paternal-derived antigens are at risk of being recognized as foreign by the maternal immune system. Suppression of the maternal immune response toward the fetus, which is mediated in part by the trophoblast, is critical to ensure embryonic survival and development. The postpartum mammary microenvironment also exhibits immunosuppressive mechanisms accompanying the massive cell death and tissue remodeling that occurs during mammary gland involution. These normal immunosuppressive mechanisms are paralleled during malignant transformation, where tumors can develop neoantigens that may be recognized as foreign by the immune system. To circumvent this, tumors can dedifferentiate and co-opt immune-suppressive mechanisms normally utilized during fetal tolerance and postpartum mammary involution. In this review, we discuss those similarities and how they can inform our understanding of cancer progression and metastasis.

Disposable amperometric immunosensor with a dual monomers-based bioconjugate for granzyme B detection in blood and cancer progress monitoring of patients

A disposable amperometric biosensor with a dual monomers-based bioconjugate was developed for granzyme B (GzmB) detection and for monitoring of the cancer progression of patients before and after immunotherapy. The biosensor was fabricated by immobilizing a GzmB monoclonal antibody (Ab₁) on a poly3'-(2-aminopyrimidyl)-2,2':5',2''-terthiophene/gold nanoparticle (pPATT/AuNP) layer. The bioconjugate nanoparticles were synthesized through self-assembly of a monomer mixture of 2,2:5,2-terthiophene-3-(p-benzoic acid) (TBA) and PATT onto AuNPs, followed by chemical binding of brilliant cresyl blue (BCB) on TBA and GzmB polyclonal antibody (Ab₂) on the PATT layer. Each sensing layer was investigated by surface analysis and electrochemical experiments. The sensor performance was assessed with selectivity, stability, reproducibility, detection limit, and real sample analysis. Under the optimized conditions, the dynamic range of GzmB was in two slopes from 3.0 to 50.0 pg/ml and from 50.0 to 1000.0 pg/ml with a detection limit of 1.75 ± 0.14 pg/ml (RSD ≤5.2%). GzmB monitoring was performed for the patient's serum samples, where a low level of GzmB was observed for lung cancer patients before immunotherapy (10.51 ± 0.99 pg/ml, RSD ≤6.2%), and the level was increased after therapy (17.19 ± 2.22 pg/ml, RSD ≤2.6%). Moreover, a significantly higher level was present in healthy persons (34.40 ± 3.92 pg/ml, RSD ≤1.4%). The cancer progression of patients before and after therapy was evaluated by monitoring GzmB levels in human serum using the proposed sensor.

Gene therapy of prostate cancer using liposomes containing perforin expression vector driven by the promoter of prostate-specific antigen gene

Perforin secreted from cytotoxic lymphocytes plays a critical role in cancer immunosurveillance. The aim of this study was to investigate the therapeutic potential of liposomes containing perforin expression vector driven by the promotor of prostate-specific antigen (PSA). The anti-tumor effect of perforin was analyzed using prostate cancer (PC) PC-3 cells in which perforin expression was controlled by Tet-on system (PC-3PRF cells). Liposomes encapsulating PSA promoter-driven perforin expression vector (pLipo) were constructed for its specific expression in PC. The anti-tumor effect of pLipo was evaluated in vitro using docetaxel-resistant PC 22Rv1 PC cell line, 22Rv1DR, and PC-3 cells in the presence of human peripheral blood mono nuclear cells (PBMCs) and also in vivo using male nude mice bearing 22Rv1DR cell-derived tumor xenograft. Induction of perforin significantly inhibited growth of PC-3PRF cells. Treatment with pLipo induced perforin expression in 22Rv1DR cells expressing PSA but not in PC-3 cells lacking it. Treatment with pLipo at a low concentration was prone to inhibit growth of both cell lines and significantly inhibited growth of 22Rv1DR cells when co-incubated with PBMCs. The combined use of pLipo at a high concentration with PBMCs showed nearly complete inhibition of 22Rv1DR cell growth. Intravenous administration of pLipo via tail vein increased the level of perforin in tumor and serum and significantly decreased the tumor volume. Our results suggest that liposome-mediated PC-specific expression of perforin could be a novel therapy for advanced PC.

Integrated analysis of prognostic immune-related genes in the tumor microenvironment of ovarian cancer

Background

Ovarian cancer (OC) is a major cause of most gynecological cancer deaths, and the rates of incidence and mortality are increasing worldwide. However, factors in the tumor microenvironment (TME) related to OC and certain prognostic markers of OC are still unknown. We aimed to identify biomarkers connected to prognostic immunity based on clinical patients’ data from The Cancer Genome Atlas (TCGA).

Methods

We used the ESTIMATE algorithm to compute the immune and matrix scores of OC patients from TCGA. Next, differentially expressed genes (DEGs) according to the immune and matrix scores were obtained. Subsequently, genes (GZMB, C2orf37, CXCL13, and UBD) connected with prognostic immunity were determined. Moreover, functional enrichment analysis and the protein-protein interaction network showed that these genes were enriched in many biological processes related to immune function. The Tumor Immune Estimation Resource (TIMER) algorithm was also used to analyze the immune prognostic genes according to six immuno-infiltrating cells.

Results

According to high/low immune-scores and matrix-score groups, 682 common genes were identified, within 420 upregulated genes and 262 downregulated genes. Gene ontology (GO) analysis of biological process primarily enriched in T cell activation, regulation of lymphocyte activation and lymphocyte differentiation. OS analysis showed 45 genes (6.6%) were relevant in the final results. The Kaplan-Meier plotter database verified the top 10 genes related to prognosis, but only GZMB, C2orf37, CXCL13 and UBD were related to overall survival (OS).

Conclusions

GZMB, CXCL13, and UBD may influence prognosis via their effects on the infiltration of immune cells and therefore represent potential targets for OC immunotherapy.

Reduced frequency of perforin-positive CD8+ T cells in menstrual effluent of endometriosis patients

Endometriosis is a widespread disease and commonly reduces the life quality of those affected. Scientific literature indicates different underlying immunological changes. Frequently examined tissues are peripheral blood, endometrial tissue and peritoneal fluid. Yet, knowledge on immunological differences in menstrual effluent (ME) is scarce. In this study, between January 2018 and August 2019, 12 women with endometriosis (rASRM classification: stages I-IV) and 11 healthy controls were included. ME was collected using menstrual cups and venous blood samples (PB) were taken. Mononuclear cells were obtained from ME (MMC) and PB (PBMC) and analyzed using flow cytometry. Concentrations of cell adhesion molecules (ICAM-I and VCAM-I) and cytokines (IL-6, IL-8 and TNF-α) were measured using ELISA. CD8 + T cells obtained from ME were significantly less often perforin-positive in women with endometriosis compared to healthy controls. A comparison between MMC and PBMC revealed that MMC contained significantly less T cells and more B cells. The CD4/CD8 ratio was significantly higher in MMC, and Tregs were significantly less frequently in MMC. In ME, T cells and NK cells expressed significantly more CD69. NK cells obtained from ME were predominantly CD56^bright/CD16^dim and had a lower frequency of perforin + cells compared to PBMC NK cells. Moreover, ICAM-1 plasma levels were significantly reduced in women with endometriosis compared to healthy controls. In conclusion, CD8 + T cells obtained from the ME were significantly less perforin-positive in endometriosis patients indicating a reduced cytotoxic potential. MMC are distinctively different from PBMC and, thus, seem to be of endometrial origin.

Direct Tumor Killing and Immunotherapy through Anti-SerpinB9 Therapy

Cancer therapies kill tumors either directly or indirectly by evoking immune responses and have been combined with varying levels of success. Here, we describe a paradigm to control cancer growth that is based on both direct tumor killing and the triggering of protective immunity. Genetic ablation of serine protease inhibitor SerpinB9 (Sb9) results in the death of tumor cells in a granzyme B (GrB)-dependent manner. Sb9-deficient mice exhibited protective T cell-based host immunity to tumors in association with a decline in GrB-expressing immunosuppressive cells within the tumor microenvironment (TME). Maximal protection against tumor development was observed when the tumor and host were deficient in Sb9. The therapeutic utility of Sb9 inhibition was demonstrated by the control of tumor growth, resulting in increased survival times in mice. Our studies describe a molecular target that permits a combination of tumor ablation, interference within the TME, and immunotherapy in one potential modality.

Intrinsic and extrinsic pathways of apoptosis: Role in cancer development and prognosis

Apoptosis, also named programmed cell death, is a fundament process required for morphogenetic homeostasis during early development and in pathophysiological conditions. It is come into existence in 1972 by work of Kerr, Wyllie and Currie and later on investigated during the research on development of the C. elegans. Trigger by several stimuli, apoptosis is necessary during the embryonic development and aging as homeostatic mechanism to control the cell population and also play a key role as defense mechanism against the immune responses and elimination of damaged cells. Cancer, a genetic disease, is a growing burden on the health and economy of both developing and developed countries. Every year there is tremendously increasing in the number of new cancer cases and mortality rate. Although, there is a significant improvement have been made in biotechnological and bioinformatic fields however, the therapeutic advantages and cancer etiology is still under explored. Several studies determined the deregulation of different apoptotic components during the cancer development and progression. Apoptosis relies on activation of distinct signaling pathways that are often deregulated in cancer. Thus, exploring the single or more than one apoptotic component underlying their expression in carcinogenesis could help to track the disease progression. Current book chapter will provide the several evidences supporting the use of different apoptotic components as prognosis and prediction markers in various human cancer types.

Clinical Activity of an hTERT-Specific Cancer Vaccine (Vx-001) in "Immune Desert" NSCLC

Simple Summary

We investigated whether there is any correlation between Vx-001 clinical activity and the tumor immune microenvironment (TIME). Our hypothesis was that Vx-001 should be clinically effective in patients with tumor-infiltrating lymphocyte (TIL) negative/low infiltrated (non-immunogenic/cold) tumors which are lacking immunosuppressive TIME but not in highly TIL infiltrated (immunogenic/hot) tumors associated with immunosuppressive TIME. In this study, we show that the tumor vaccine Vx-001 offers a clinical benefit in patients with tumors lacking or weakly infiltrated with TILs. In contrast, Vx-001 is completely inactive in the context of tumors highly infiltrated with TILs, thus confirming our hypothesis. TIL negative/low tumor signature is an independent predictive factor of Vx-001 efficacy. To our knowledge, this is the first study showing an inverse correlation between tumor vaccine efficacy and the presence of TILs. These data support the selection of patients with TIL negative or low infiltrated tumors (i.e., patients known to be resistant to immune checkpoint inhibitors (ICIs) and with poor prognosis) as the best candidates to receive tumor vaccines and to get a clinical benefit from vaccination.

Abstract

Background: Tumors can be separated into immunogenic/hot and non-immunogenic/cold on the basis of the presence of tumor-infiltrating lymphocytes (TILs), the expression of PD-L1 and the tumor mutation burden (TMB). In immunogenic tumors, TILs become unable to control tumor growth because their activity is suppressed by different inhibitory pathways, including PD-1/PD-L1. We hypothesized that tumor vaccines may not be active in the immunosuppressive microenvironment of immunogenic/hot tumors while they could be efficient in the immune naïve microenvironment of non-immunogenic/cold tumors. Methods: The randomized phase II Vx-001-201 study investigated the effect of the Vx-001 vaccine as maintenance treatment in metastatic non-small cell lung cancer (NSCLC) patients. Biopsies from 131 (68 placebo and 63 Vx-001) patients were retrospectively analyzed for PD-L1 expression and TIL infiltration. TILs were measured as tumor-associated immune cells (TAICs), CD3-TILs, CD8-TILs and granzyme B-producing TILs (GZMB-TILs). Patients were distinguished into PD-L1(+) and PD-L1(-) and into TIL high and TIL low. Findings: There was no correlation between PD-L1 expression and Vx-001 clinical activity. In contrast, Vx-001 showed a significant improvement of overall survival (OS) vs. placebo in TAIC low (21 vs. 8.1 months, p = 0.003, HR = 0.404, 95% CI 0.219–0.745), CD3-TIL low (21.6 vs. 6.6 months, p < 0.001, HR = 0.279, 95% CI 0.131–0.595), CD8-TIL low (21 vs. 6.6 months, p < 0.001; HR = 0.240, 95% CI 0.11–0.522) and GZMB-TIL low (20.7 vs. 11.1 months, p = 0.011, HR = 0.490, 95% CI 0.278–0.863). Vx-001 did not offer any clinical benefit in patients with TAIC high, CD3-TIL high, CD8-TIL high or GZMB-TIL high tumors. CD3-TIL, CD8-TIL and GZMB-TIL were independent predictive factors of Vx-001 efficacy. Conclusions: These results support the hypothesis that Vx-001 may be efficient in patients with non-immunogenic/cold but not with immunogenic/hot tumors.

The Profile and Role of Tumor-infiltrating Lymphocytes in Hepatocellular Carcinoma: An Immunohistochemical Study

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Tumor-infiltrating lymphocytes (TILs) are a class of cells that form the tumor microenvironment and thus have an effect on carcinogenesis. The aim of this study was to investigate the immunohistochemical expression of CD8, CD4, cytotoxic T lymphocyte-associated protein-4 (CTLA-4), and granzyme B in HCC and their correlation with clinicopathologic parameters and prognosis. This study was carried out on 112 cases of HCC. High percentage of CD8+ TILs was associated with large tumors and adjacent noncirrhotic liver. High percentage of CD4+ TILs and high CD4 to CD8 ratio were associated with nonviral etiology, low alpha fetoprotein, and direct acting antiviral treatment. High percentage of CTLA-4-positive TILs tended to be associated with high-grade HCC, while a high percentage of CTLA-4 in tumor cells was associated with multiple lesions and low tumor grade. High percentage of granzyme B+ TILs was associated with low grade, early stage, and absence of tumor recurrence. High CD4 percentage and high CD4/CD8 ratio affected patients' overall survival. There is a dynamic interaction between the different subsets of lymphocytes in the environment of HCC manifested by coparallel expression of CD4 and CD8 augmenting the expression of CTLA-4, and only CD8 augments the expression of granzyme B. This opens the gate for the beneficial role of immunotherapy in the management of HCC, reducing recurrence and improving survival.

Ibrutinib treatment inhibits breast cancer progression and metastasis by inducing conversion of myeloid-derived suppressor cells to dendritic cells

BACKGROUND

Ibrutinib is a Bruton's tyrosine kinase (BTK) and interleukin-2-inducible kinase (ITK) inhibitor used for treating chronic lymphocytic leukaemia (CLL) and other cancers. Although ibrutinib is known to inhibit the growth of breast cancer cell growth in vitro, its impact on the treatment and metastasis of breast cancer is unclear.

METHODS

Using an orthotopic mouse breast cancer model, we show that ibrutinib inhibits the progression and metastasis of breast cancer.

RESULTS

Ibrutinib inhibited proliferation of cancer cells in vitro, and Ibrutinib-treated mice displayed significantly lower tumour burdens and metastasis compared to controls. Furthermore, the spleens and tumours from Ibrutinib-treated mice contained more mature DCs and lower numbers of myeloid-derived suppressor cells (MDSCs), which promote disease progression and are linked to poor prognosis. We also confirmed that ex vivo treatment of MDSCs with ibrutinib switched their phenotype to mature DCs and significantly enhanced MHCII expression. Further, ibrutinib treatment promoted T cell proliferation and effector functions leading to the induction of antitumour T_H1 and CTL immune responses.

CONCLUSIONS

Ibrutinib inhibits tumour development and metastasis in breast cancer by promoting the development of mature DCs from MDSCs and hence could be a novel therapeutic agent for the treatment of breast cancer.

Understanding the Complexity of the Tumor Microenvironment in K-ras Mutant Lung Cancer: Finding an Alternative Path to Prevention and Treatment

Kirsten rat sarcoma viral oncogene (K-ras) is a well-documented, frequently mutated gene in lung cancer. Since K-ras regulates numerous signaling pathways related to cell survival and proliferation, mutations in this gene are powerful drivers of tumorigenesis and confer prodigious survival advantages to developing tumors. These malignant cells dramatically alter their local tissue environment and in the process recruit a powerful ally: inflammation. Inflammation in the context of the tumor microenvironment can be described as either antitumor or protumor (i.e., aiding or restricting tumor progression, respectively). Many current treatments, like immune checkpoint blockade, seek to augment antitumor inflammation by alleviating inhibitory signaling in cytotoxic T cells; however, a burgeoning area of research is now focusing on ways to modulate and mitigate protumor inflammation. Here, we summarize the interplay of tumor-promoting inflammation and K-ras mutant lung cancer pathogenesis by exploring the cytokines, signaling pathways, and immune cells that mediate this process.

Evaluating CAR-T Cell Therapy in a Hypoxic 3D Tumor Model

Despite its revolutionary success in hematological malignancies, chimeric antigen receptor T (CAR-T) cell therapy faces disappointing clinical results in solid tumors. The poor efficacy has been partially attributed to the lack of understanding in how CAR-T cells function in a solid tumor microenvironment. Hypoxia plays a critical role in cancer progression and immune editing, which potentially results in solid tumors escaping immunosurveillance and CAR-T cell-mediated cytotoxicity. Mechanistic studies of CAR-T cell biology in a physiological environment has been limited by the complexity of tumor-immune interactions in clinical and animal models, as well as by a lack of reliable in vitro models. A microdevice platform that recapitulates a 3D tumor section with a gradient of oxygen and integrates fluidic channels surrounding the tumor for CAR-T cell delivery is engineered. The design allows for the evaluation of CAR-T cell cytotoxicity and infiltration in the heterogeneous oxygen landscape of in vivo solid tumors at a previously unachievable scale in vitro.

Combination of immune checkpoint blockade with DNA cancer vaccine induces potent antitumor immunity against P815 mastocytoma

DNA vaccination against cancer has become a promising strategy for inducing a specific and long-lasting antitumor immunity. However, DNA vaccines fail to generate potent immune responses when used as a single therapy. To enhance their activity into the tumor, a DNA vaccine against murine P815 mastocytoma was combined with antibodies directed against the immune checkpoints CTLA4 and PD1. The combination of these two strategies delayed tumor growth and enhanced specific antitumor immune cell infiltration in comparison to the corresponding single therapies. The combination also promoted IFNg, IL12 and granzyme B production in the tumor microenvironment and decreased the formation of liver metastasis in a very early phase of tumor development, enabling 90% survival. These results underline the complementarity of DNA vaccination and immune checkpoint blockers in inducing a potent immune response, by exploiting the generation of antigen-specific T cells by the vaccine and the ability of immune checkpoint blockers to enhance T cell activity and infiltration in the tumor. These findings suggest how and why a rational combination therapy can overcome the limits of DNA vaccination but could also allow responses to immune checkpoint blockers in a larger proportion of subjects.

Regulatory T cells and potential inmmunotherapeutic targets in lung cancer

Lung cancer and metastasis are two of the most lethal diseases globally and seldom have effective therapies. Immunotherapy is considered as one of the powerful alternatives. Regulatory T cells (Tregs) can suppress the activation of the immune system, maintain immune tolerance to self-antigens, and contribute to immunosuppression of antitumor immunity, which is critical for tumor immune evasion in epithelial malignancies, including lung cancer. The present review gives an overview of the biological functions and regulations of Tregs associated with the development of lung cancer and metastasis and explores the potentials of Treg-oriented therapeutic targets. Subsets and features of Tregs mainly include naturally occurring Tregs (nTregs) (CD4(+) nTregs and CD8(+) nTregs) and adaptive/induced Tregs (CD4(+) iTregs and CD8(+) iTregs). Tregs, especially in circulation or regional lymph nodes, play an important role in the progress and metastasis of lung cancer and are considered as therapeutic targets and biomarkers to predict the survival length and recurrence of lung cancer. Increasing understanding of Tregs' functional mechanisms will lead to a number of clinical trials on the discovery and development of Treg-oriented new therapies. Tregs play important roles in lung cancer and metastasis, and the understanding of Tregs becomes more critical for clinical applications and therapies. Thus, Tregs and associated factors can be potential therapeutic targets for lung cancer immunotherapy.

Epitelial-to-mesenchimal transition and invasion are upmodulated by tumor-expressed granzyme B and inhibited by docosahexaenoic acid in human colorectal cancer cells

BACKGROUND

Granzyme B (GrB) is a serine protease, traditionally known as expressed by cytotoxic lymphocytes to induce target cell apoptosis. However, it is emerging that GrB, being also produced by a variety of normal and neoplastic cells and potentially acting on multiple targets, might represent a powerful regulator of a wide range of fundamental biological processes. We have previously shown that GrB is expressed in urothelial carcinoma tissues and its expression is associated to both pathological tumor spreading and EMT. We have also shown that docosahexaenoic acid (DHA), a dietary ω-3 polyunsaturated fatty acid with anti-tumor activity, while inhibiting urothelial and pancreatic carcinoma cell invasion also inhibited their GrB expression in vitro. In this study, we characterized a panel of colorectal carcinoma (CRC) cells, with different invasive capabilities, for GrB expression and for the contribution of GrB to their EMT and invasive phenotype. In addition, we investigated the effect of DHA on CRC cell-associated GrB expression, EMT and invasion.

METHODS

The expression levels of GrB and EMT-related markers were evaluated by Western blotting. GrB knockdown was performed by Stealth RNAi small interfering RNA silencing and ectopic GrB expression by transfection of human GrB vector. Cell invasion was determined by the BioCoat Matrigel invasion chamber test.

RESULTS

GrB was produced in 57.1% CRC cell lines and 100% CRC-derived Cancer Stem Cells. Although GrB was constitutive expressed in both invasive and noninvasive CRC cells, GrB depletion in invasive CRC cells downmodulated their invasion in vitro, suggesting a contribution of GrB to CRC invasiveness. GrB loss or gain of function downmodulated or upmodulated EMT, respectively, according to the analysis of cancer cell expression of three EMT biomarkers (Snail1, E-cadherin, N-cadherin). Moreover, TGF-β1-driven EMT was associated to the enhancement of GrB expression in CRC cell lines, and GrB depletion led to downmodulation of TGF-β1-driven EMT. In addition, DHA inhibited GrB expression, EMT and invasion in CRC cells in vitro.

CONCLUSIONS

These findings present a novel role for GrB as upmodulator of EMT in CRC cells. Moreover, these results support the use of DHA, a dietary compound without toxic effects, as adjuvant in CRC therapy.

Low intratumoral regulatory T cells and high peritumoral CD8(+) T cells relate to long-term survival in patients with pancreatic ductal adenocarcinoma after pancreatectomy

The prognosis for pancreatic ductal adenocarcinoma (PDAC) remains extremely poor. Recent studies have focused on the role of lymphocytes in the PDAC microenvironment. Using immunohistochemistry, our study explored the clinical significance of intratumoral or peritumoral CD4(+)Foxp3(+) regulatory T cells (Tregs) and CD8(+) T cells in the tumor microenvironment and analyzed their relation to the prognosis of PDAC in a consecutive series of 92 patients after resection. CD8(+) T cells were more frequently seen within peritumoral sites, while CD4(+)Foxp3(+) Tregs were more frequent within intratumoral areas. Neither exhibited any relationship with other clinicopathologic factors. Patients with low levels of intratumoral Tregs had longer disease-free survival than those with higher levels (DFS 22.2 vs. 11.2 months, p < 0.001), and patients with higher levels of peritumoral CD8(+) T cells had longer overall survival than those with lower levels (OS 31.0 vs. 14.2 months, p < 0.001). Multivariate analysis demonstrated that intratumoral Tregs (hazard ratio, HR 3.39, p = 0.010) and peritumoral CD8(+) T cells (HR 0.10, p < 0.001) are related to DFS and OS, respectively. These results indicate that intratumoral Tregs are a negative predictor of DFS, while peritumoral CD8(+) T cells are a positive predictor of OS for PDAC patients with pancreatectomy.

Comparative analysis of CD4+ and CD8+ T cells in tumor tissues, lymph nodes and the peripheral blood from patients with breast cancer

Background: CD4+ and CD8+ T cells are the main types of lymphocytes in cell-mediated immunity and play a central role in the induction of efficient immune responses against tumors. The frequencies of T cell subtypes in the peripheral blood and tumor tissues, and draining lymph nodes (dLN) can be considered as useful markers for evaluation of the immune system in cancers. Methods: In this study, the frequencies of CD4+ and CD8+ T cells in blood, tumor tissues, and dLN samples of breast cancer patients were compared with each other and with similar tissues from normal individuals. Immunophenotyping was carried out by flow cytometry and the expression levels of CXCL10, granzyme B, and mammaglobin were evaluated by real-time PCR. Results: In the peripheral blood, there were no differences in the T cell subsets between the patients and the normal individuals. The frequency of CD8+ T cells was significantly higher in tumor tissue than normal breast tissues while granzyme B expression was similar. Based on mammaglobin expression levels, dLN have been classified into micro- and macro-metastatic dLN. We found significantly lower frequency of CD4+ in macro-metastatic dLN than micro-metastatic dLN. CD8+ frequency was similar in both dLN; however, granzyme B expression was higher in micro-metastatic ones. There was not any significant difference in CXCL10 expression between the two types of dLN. Conclusion: Based on our results, although the tumor does not affect the systemic immunity, tumoral cells affect the local immune system in the tumoral tissues and the metastatic dLN.

Expression, purification and anticancer analysis of GST-tagged human perforin and granzyme B proteins in human laryngeal cancer Hep-2 cells

Granzyme B and perforin, two major effector molecules in the granule-mediated cytolytic pathway, are thought to be involved in suppression of tumor progression. In this study, the pGEX-4T-1 expression vector was used to express full-length human perforin or granzyme B as a GST-tagged fusion protein in Escherichia coli (E. coli). GST-tagged proteins were induced with IPTG and purified by GSTrap 4B columns. Purified fusion proteins migrated at the predicted molecular mass on SDS-PAGE and were recognized by specific antibodies. Moreover, the fusion proteins can induce apoptosis and directly inhibit the growth of human laryngeal cancer Hep-2 cells in vitro. These results suggest that active perforin and granzyme B fusion proteins can be produced in E. coli and exhibit anticancer potential in laryngeal cancer cells.

Tumor-induced CD8+ T-cell dysfunction in lung cancer patients

Lung cancer is the leading cause of cancer deaths worldwide and one of the most common types of cancers. The limited success of chemotherapy and radiotherapy regimes have highlighted the need to develop new therapies like antitumor immunotherapy. CD8+ T-cells represent a major arm of the cell-mediated anti-tumor response and a promising target for developing T-cell-based immunotherapies against lung cancer. Lung tumors, however, have been considered to possess poor immunogenicity; even so, lung tumor-specific CD8+ T-cell clones can be established that possess cytotoxicity against autologous tumor cells. This paper will focus on the alterations induced in CD8+ T-cells by lung cancer. Although memory CD8+ T-cells infiltrate lung tumors, in both tumor-infiltrating lymphocytes (TILs) and malignant pleural effusions, these cells are dysfunctional and the effector subset is reduced. We propose that chronic presence of lung tumors induces dysfunctions in CD8+ T-cells and sensitizes them to activation-induced cell death, which may be associated with the poor clinical responses observed in immunotherapeutic trials. Getting a deeper knowledge of the evasion mechanisms lung cancer induce in CD8+ T-cells should lead to further understanding of lung cancer biology, overcome tumor evasion mechanisms, and design improved immunotherapeutic treatments for lung cancer.

Potential Role of Thymosin-alpha1 Adjuvant Therapy for Glioblastoma

Glioblastomas are high-grade, malignant CNS neoplasms that are nearly always fatal within 12 months of diagnosis. Immunotherapy using proinflammatory cytokines such as IL-2 or IL-12 may prolong survival with glioblastoma. Thymosin-α1 (Talpha1) is a thymic hormone and immunemodulator that increase IL-2 production and T-cell proliferation. We examined potential therapeutic effects of Talpha1 in experimental in vivo glioblastoma, and characterized Talpha1's anti-tumor effects in vitro. Rar 9L cells (10⁴) were implanted into the right frontal lobe of adult Long Evans rats that were subsequently treated with vehicle, BCNU, Talpha1, or Talpha1+BCNU from postoperative day 6. Talpha1+BCNU significantly lowered tumor burdens, and increased cure rates. In vitro experiments demonstrated that Talpha1 had no direct effect on viability or mitochondrial function, and instead, it increased expression of pro-apoptosis genes, including FasL, FasR and TNFα-R1 (65.89%, 44.08%, and 22.18%, resp.), and increased 9L cell sensitivity to oxidative stress. Moreover, Talpha1 enhanced 9L cell sensitivity to both Granzyme B- and BCNU-mediated killing. The findings suggest that Talpha1 enhances BCNUmediated eradication of glioblastoma in vivo, and that Talpha1 mediates its effects by activating pro-apoptosis mechanisms, rendering neoplastic cells more sensitive to oxidative stress and immune-mediated killing by Granzyme B and chemotherapeutic agents.

Analysis of the mononuclear inflammatory cell infiltrate in the normal breast, benign proliferative breast disease, in situ and infiltrating ductal breast carcinomas: preliminary observations

BACKGROUND

Mammary carcinogenesis is a multistep process entailing the transition from normal breast to benign proliferative breast disease (ductal hyperplasia) to ductal carcinoma in situ to infiltrating ductal carcinoma.

HYPOTHESIS

These transitions are associated with changes in the mononuclear inflammatory cell infiltrate.

MATERIALS AND METHODS

A total of 53 mastectomy specimens of normal breast, benign proliferative breast disease, ductal carcinoma in situ and infiltrating ductal carcinoma were evaluated for mononuclear inflammatory cell infiltrate by using immunohistological methods and monoclonal antibodies including CD20, CD68, CD3 and granzyme B, histiocytes, T cells and cytotoxic T cells.

RESULTS

Transitions from normal breast to the subsequent tissue with lesions (normal skin v benign proliferative breast disease v ductal carcinoma in situ v infiltrating ductal carcinoma) were associated with significantly (p<0.01) increased mean (SD) density of mononuclear inflammatory cell infiltrate at the parenchyma (3.2 (1.0) v 26.4 (7.8) v 33.6 (7.9) v 39.1 (4.7) for CD20+ B cells; 2.8 (1.0) v 81.5 (14.0) v 84.0 (14.9) v103.7 (3.9) for CD3; 1.3 (2.0) v 3.8 (4.0) v 12.7 (23) v 22.1 (25.0) for CD68+ macrophages; 2.0 (1.0) v 58.3 (5.0) v 60.0 (10.0) v 74.1 (28.0) for granzyme B+ cytotoxic T cells) and at the stroma (0.7 (1.0) v 3.0 (5.0) v 13.3 (20) v 16.7 (30.0) for CD20+ B cells; 1.0 (2.06) v 4.0 (2.5) v 16.7 (5.0) v 21.7 (15) for CD68+ macrophages; 1.4 (0.6) v 4.2 (1.2) v 46.6 (16.7) v 77.0 (5.0) for CD3+ cells and 0 (0) v 0.5 (1.0) v 0.7 (1.0) v 0.7 (1.0) for granzyme B+ cytotoxic T cells).

CONCLUSIONS

The increased mononuclear inflammatory cell infiltrate during mammary carcinogenesis may reflect non-specific or specific immunological processes.

Differential expression of Granzyme B in tumor cells between primary and metastatic gastric cancer and its potential role in tumor angiogenesis

AIM: To investigate the potential role of Granzyme B (GrB) in the biological behavior of gastric cancer, such as angiogenesis and lymphatic metastasis.

METHODS: The identification of GrB expression in gastric cancer cells was performed immunohistologically in patients with primary gastric cancers (PGC, n = 35) and lymphoid metastatic gastric cancer (LMGC, n = 23), and GrB⁺ cytotoxic T lymphocytes (CTL) served as positive internal control.The antibodies recognizing vascular endothelial growth factor (VEGF) and CD34 were employed to detect the VEGF expression and microvascular density (MVD), respectively.

RESULTS: The positive rate of GrB expression was relatively lower in PGC with lymphoid metastasis than that without metastasis, but no significant difference was observed (P = 0.709). The positive rate of GrB expression in LMGC was significantly higher than that in the corresponding PGC (P = 0.038). The synchronous expression rate of GrB and VEGF came up to 57.1%, while there was no significant correlation between them. A significant negative correlation was found between the level of GrB expression and MVD (r = -0.421, P = 0.012) in PGC. VEGF expression was showed to have no significant effect on MVD in GrB positive PGC (P = 0.494). However, the decreased MVD in VEGF⁺ PGC was remarkably associated with GrB expression (P = 0.023), and similar feature was exhibited in VEGF negative PGC (P = 0.134). The lowest and the highest MVD were demonstrated in PGC with positive GrB and negative VEGF, and PGC with positive VEGF and negative GrB, respectively (P= 0.013).

CONCLUSION: The over-expression of GrB in gastric cancer cells might contribute to the inhibition of tumor angiogenesis, but also might contribute to the survival potential of diffused tumor cells in lymph gland.

Beta-endorphin modulation of interferon-gamma, perforin and granzyme B levels in splenic NK cells: effects of ethanol

The effects of ethanol and beta-endorphin (beta-EP) on productions of cytolytic factors granzyme B, perforin and IFN-gamma in splenic rat NK cells were determined. Intracranial administration of beta-EP increased protein and mRNA levels of cytolytic factors in NK cells. Chronic ethanol feeding reduced the basal and beta-EP-induced levels of cytolytic factors in NK cells. In vitro treatment of beta-EP on NK cells increased the levels of perforin, granzyme B and IFN-gamma and their mRNA transcripts, whereas ethanol pre-treatment prevented beta-EP effects on cytolytic factors in these cells. These results suggest that beta-EP and ethanol interact to regulate NK cell functions.

Expression of endogenous granzyme B in a subset of human primary breast carcinomas

Granzyme B (GrB) is the prototypic member of a serine protease family primarily used by cytotoxic lymphocytes to kill target cells. We report here that, by immunohistochemical staining of paraffin-embedded tumour sections, GrB protein was unexpectedly detected in malignant cells of a subset of breast cancers and their adjacent reactive endothelial and mesenchymal cells in which endogenous retinoblastoma protein (pRB) is overexpressed. The identity of the endogenous GrB was further confirmed experimentally in RB-deficient breast carcinoma cell culture upon overexpression of ectopic pRB. Our finding extends the recent paradigm-shifting trend for a more diverse biological role of granzyme B, and might provide a rational basis for exploring its potential prognostic value in a variety of human cancers.

Expression of cytolytic lymphocyte-associated antigens in pulmonary lymphomatoid granulomatosis

Paraffin-embedded lung wedge biopsy specimens from 14 patients with pulmonary lymphomatoid granulomatosis (LYG) were analyzed using immunoperoxidase stains specific for T cell- and natural killer cell-associated antigens. Nine cases had a minor population of CD20+ large B-cells (B-cell LYG) amidst a background of CD3- and betaF1-immunoreactive T cells. In 8 of the 9 B-cell LYG cases, the majority of the background T lymphocytes had a cytotoxic phenotype as defined by the expression of CD8 and the cytotoxic granule proteins TIA-1 (granule membrane protein 17) and granzyme B. Five cases lacked CD20+ large cells and, instead, showed predominantly CD3+ and betaF1 + T cells (T-cell LYG). Whereas the small, medium, and large atypical lymphocytes were all positive for CD3 and betaF1 in the T-cell LYG cases, immunoreactivity for CD8, TIA-1, and granzyme B was limited to the small lymphocytes, with a distribution indistinguishable from that seen in B-cell LYG. These findings indicate that LYG is composed of a heterogeneous group of lymphoproliferative disorders that share, as unifying features, a relative paucity of neoplastic cells and a prominent reactive infiltrate rich in cytolytic lymphocytes.