Ectopic lymphoid structures function as microniches for tumor progenitor cells in hepatocellular carcinoma

Infiltrating pattern and prognostic value of tertiary lymphoid structures in resected non-functional pancreatic neuroendocrine tumors

BACKGROUND

Tertiary lymphoid structures (TLS) are associated with favorable survival and play a critical role in most solid tumors. However, investigations of TLS are lacking in patients with grade 1 or grade 2 (G1/G2) non-functional pancreatic neuroendocrine tumors (NF-PanNETs). This study aimed to investigate the presence, cellular composition, association with tumor-infiltrating immune cells, and prognostic value of TLS in G1/G2 NF-PanNETs.

METHODS

Tumor tissues from a 182-patient Fudan cohort and a 125-patient external validation set were assessed by H&E staining, immunohistochemistry, and/or multispectral fluorescent immunohistochemistry.

RESULTS

TLS were identified in more than one-third of patients with G1/G2 NF-PanNETs and were located peritumorally, either just outside the tumor tissue or in the stromal area. TLS were mainly composed of B-cell follicles with germinal centers and T-cell zones with dendritic cells. Kaplan-Meier analyses showed that the presence of TLS correlated with both longer recurrence-free survival (RFS, p<0.001) and overall survival (OS, p=0.001), but the number of TLS had no prognostic significance. Multivariate Cox-regression analyses demonstrated that the presence of TLS, WHO classification, and 8th edition American Joint Committee on Cancer (AJCC8th) tumor-node-metastasis (TNM) stage were independent prognostic factors for RFS (p=0.004, p=0.001, and p<0.001, respectively) and OS (p=0.009, p=0.008, and p=0.019, respectively). These results were confirmed using an external validation set. Finally, a nomogram incorporating the presence of TLS was constructed to predict the probability of 5-year RFS of resected G1/G2 NF-PanNETs, which improved on the current WHO classification and AJCC8th TNM stage.

CONCLUSIONS

The presence of TLS is an independent and favorable predictor of resected G1/G2 NF-PanNETs, which may play a role in cancer immunobiology.

Tumor-Infiltrating Lymphocytes and Their Prognostic Value in Cutaneous Melanoma

Recent breakthroughs in tumor immunotherapy such as immune checkpoint blockade (ICB) antibodies, have demonstrated the capacity of the immune system to fight cancer in a number of malignancies such as melanoma and lung cancer. The numbers, localization and phenotypes of tumor-infiltrating lymphocytes (TIL) are not only predictive of response to immunotherapy but also key modulators of disease progression. In this review, we focus on TIL profiling in cutaneous melanoma using histopathological approaches and highlight the observed prognostic value of the primary TIL subsets. The quantification of TIL in formalin-fixed tumor samples ranges from visual scoring of lymphocytic infiltrates in H&E to multiplex immunohistochemistry and immunofluorescence followed by enumeration using image analysis software. Nevertheless, TIL enumeration in the current literature primarily relies upon single marker immunohistochemistry analyses of major lymphocyte subsets such as conventional T cells (CD3, CD4, CD8), regulatory T cells (FOXP3) and B cells (CD20). We review key studies in the literature on associations between TIL subsets and patient survival. We also cover recent findings with respect to the existence of ectopic lymphoid aggregates found in the TME which are termed tertiary lymphoid structures (TLS) and are generally a positive prognostic feature. In addition to their prognostic significance, the existence of various TIL sub-populations has also been reported to predict a patient's response to ICB. Thus, the literature on the predictive potential of TIL subsets in melanoma patients receiving ICB has also been discussed. Finally, we describe recently developed state-of-the-art profiling approaches for tumor infiltrating immune cells such as digital pathology scoring algorithms (e.g., Immunoscore) and multiplex proteomics-based immunophenotyping platforms (e.g., imaging mass cytometry). Translating these novel technologies have the potential to revolutionize tumor immunopathology leading to altering our current understanding of cancer immunology and dramatically improving outcomes for patients.

PKCλ/ι Loss Induces Autophagy, Oxidative Phosphorylation, and NRF2 to Promote Liver Cancer Progression

Oxidative stress plays a critical role in liver tissue damage and in hepatocellular carcinoma (HCC) initiation and progression. However, the mechanisms that regulate autophagy and metabolic reprogramming during reactive oxygen species (ROS) generation, and how ROS promote tumorigenesis, still need to be fully understood. We show that protein kinase C (PKC) λ/ι loss in hepatocytes promotes autophagy and oxidative phosphorylation. This results in ROS generation, which through NRF2 drives HCC through cell-autonomous and non-autonomous mechanisms. Although PKCλ/ι promotes tumorigenesis in oncogene-driven cancer models, emerging evidence demonstrate that it is a tumor suppressor in more complex carcinogenic processes. Consistently, PKCλ/ι levels negatively correlate with HCC histological tumor grade, establishing this kinase as a tumor suppressor in liver cancer.

Cell and tissue engineering in lymph nodes for cancer immunotherapy

In cancer, lymph nodes (LNs) coordinate tumor antigen presentation necessary for effective antitumor immunity, both at the levels of local cellular interactions and tissue-level organization. In this review, we examine how LNs may be engineered to improve the therapeutic outcomes of cancer immunotherapy. At the cellular scale, targeting the LNs impacts the potency of cancer vaccines, immune checkpoint blockade, and adoptive cell transfer. On a tissue level, macro-scale biomaterials mimicking LN features can function as immune niches for cell reprogramming or delivery in vivo, or be utilized in vitro to enable preclinical testing of drugs and vaccines. We additionally review strategies to induce ectopic lymphoid sites reminiscent of LNs that may improve antitumor T cell priming.

Immune Landscape in Tumor Microenvironment: Implications for Biomarker Development and Immunotherapy

Integration of the tumor microenvironment as a fundamental part of the tumorigenic process has undoubtedly revolutionized our understanding of cancer biology. Increasing evidence indicates that neoplastic cells establish a dependency relationship with normal resident cells in the affected tissue and, furthermore, develop the ability to recruit new accessory cells that aid tumor development. In addition to normal stromal and tumor cells, this tumor ecosystem includes an infiltrated immune component that establishes complex interactions that have a critical effect during the natural history of the tumor. The process by which immune cells modulate tumor progression is known as immunoediting, a dynamic process that creates a selective pressure that finally leads to the generation of immune-resistant cells and the inability of the immune system to eradicate the tumor. In this context, the cellular and functional characterization of the immune compartment within the tumor microenvironment will help to understand tumor progression and, ultimately, will serve to create novel prognostic tools and improve patient stratification for cancer treatment. Here we review the impact of the immune system on tumor development, focusing particularly on its clinical implications and the current technologies used to analyze immune cell diversity within the tumor.

Biological mechanisms of ectopic lymphoid structure formation and their pathophysiological significance

Ectopic lymphoid structures (ELS) or tertiary lymphoid organs are structures with the organization similar to the one of secondary lymphoid organs, formed in non-lymphoid tissues. They are considered to be an important site for the lymphocytic physiological and pathological role in conditions such are chronic infections, autoimmune diseases, cancer, and allograft rejection. Although similar to the secondary lymphoid tissues, the initiation of ELS formation is not preprogramed and requires chronic inflammation, expression of homeostatic chemokines, and lymphotoxin beta receptor activation. Importantly, while ELS formation may be considered beneficiary in antimicrobial and antitumor immunity, the persistence of these active lymphoid structures within the tissue increase the chance for development of autoimmunity and lymphoma. This paper is providing an overview of biological mechanisms involved in ELS formation, as well as the overview of the pathophysiological role of these structures. In addition, the paper discusses the possibility to therapeutically target ELS formation, bearing in mind their bivalent nature and role in different pathophysiological conditions.

Resistance to cancer immunotherapy in metastatic renal cell carcinoma

The prognosis of metastatic clear cell renal cell carcinoma (mccRCC) has changed dramatically over the years with the emergence of immune checkpoint inhibitors (ICI) used alone, or in combination with another ICI, or with vascular endothelial growth factor receptor tyrosine kinase inhibitor. Although major response rates have been observed with ICI, many patients do not respond, reflecting primary resistance, and durable responses remain exceptional, reflecting secondary resistance. Factors contributing to primary and acquired resistance are manifold, including patient-intrinsic factors, tumor cell-intrinsic factors and factors associated with the tumoral microenvironment (TME). While some mechanisms of resistance are common to several tumor types, others are specific to mccRCC. Predictive biomarkers and alternative strategies are needed to overcome this resistance. This review provides an overview of the major ICI resistance mechanisms, highlights the potential of the TME to induce resistance to ICI, and discusses the predictive biomarkers available to guide therapeutic choice.

Omics-derived hepatocellular carcinoma risk biomarkers for precision care of chronic liver diseases

Precise hepatocellular carcinoma (HCC) risk prediction will play increasingly important roles with the contemporary HCC etiologies, that is, non-alcoholic fatty liver disease and resolved hepatitis C virus infection. Because the HCC incidence rate in this emerging patient population is relatively low (~1% per year), identification of a subset of patients at the highest risk is critical to concentrate the effort and resources of regular HCC screening to those who most need it. Omics profiling has been derived using several candidate HCC risk biomarkers, which could refine HCC screening by enabling individual risk-based personalized or risk-stratified patient management. Various types of biomolecules have been explored as sources of information to predict HCC risk at various time horizons. Germline DNA polymorphisms likely reflect race/ethnicity- and/or etiology-specific susceptibility to HCC development or chronic liver disease progression toward carcinogenesis. Transcriptomic dysregulations in the diseased liver capture functional molecular status supporting oncogenesis such as inflammatory pathway and myofibroblast activation. Circulating nucleic acids, proteins, and metabolites could serve as less-invasive measures of molecular HCC risk. Characterization of gut microbiota could also inform HCC risk estimation. Each biomarker could have its niche of clinical application depending on logistics of use, performance, and costs with a goal to eventually improve patient prognosis as a part of the whole algorithm of chronic liver disease management.

High mutation load, immune-activated microenvironment, favorable outcome, and better immunotherapeutic efficacy in melanoma patients harboring MUC16/CA125 mutations

Immunotherapies have dramatically improved survival outcome for patients with melanoma. MUC16 encodes cancer antigen 125 (CA125), which is frequently mutated in melanoma. In this study, we correlated the MUC16 mutational status with the following: tumor mutation burden (TML), multiple immune-related signals in microenvironment, deregulated pathways, survival outcome, and immunotherapeutic efficacy. We found that patients with MUC16 mutations had significantly higher TML than those without it. Enriched pro-inflammatory CD8 T cells and M1 macrophages, enhanced interferon gamma (IFNγ) and T cell-inflamed signatures, and increased cytolytic activity were associated with MUC16 mutations. Immune-suppressive M2 macrophages were enriched in patients with wild-type MUC16. Immune checkpoints expression (e.g., PD-L1, PD-1 and CTLA-4) was also elevated in patients with MUC16 mutations. Immune response relevant circuits were among the top enriched pathways in samples with MUC16 mutations. Patients with MUC16 mutations exhibited a significantly better prognosis. For patients who received immunotherapy, the presence of MUC16 mutations was associated with a better response rate and survival outcome in male patients but not in female or overall patients. These findings provide new implications for tailoring immunotherapeutic strategies for melanoma patients.

NCOA5 deficiency promotes a unique liver protumorigenic microenvironment through p21WAF1/CIP1 overexpression, which is reversed by metformin

Prevention and treatment options for hepatocellular carcinoma (HCC) are presently limited, underscoring the necessity for further elucidating molecular mechanisms underlying HCC development and identifying new prevention and therapeutic targets. Here, we demonstrate a unique protumorigenic niche in the livers of Ncoa5+/- mouse model of HCC, which is characterized by altered expression of a subset of genes including p21WAF1/CIP1 and proinflammatory cytokine genes, increased putative hepatic progenitors, and expansions of activated and tissue-resident memory (TRM) CD8+ T lymphocytes, myeloid-derived suppressor cells (MDSCs), and alternatively activated M2 macrophages. Importantly, prophylactic metformin treatment reversed these characteristics including aberrant p21WAF1/CIP1 expression and subsequently reduced HCC incidence in Ncoa5+/- male mice. Heterozygous deletion of the p21WAF1/CIP1 gene alleviated the key features associated with the protumorigenic niche in the livers of Ncoa5+/- male mice. Moreover, transcriptomic analysis reveals that preneoplastic livers of Ncoa5+/- mice are similar to the livers of nonalcoholic steatohepatitis patients as well as the adjacent noncancerous liver tissues of a subset of HCC patients with a relatively poor prognosis. Together, our results suggest that p21WAF1/CIP1 overexpression is essential in the development of protumorigenic microenvironment induced by NCOA5 deficiency and metformin prevents HCC development via alleviating p21WAF1/CIP1 overexpression and protumorigenic microenvironment.

12-Chemokine signature, a predictor of tumor recurrence in colorectal cancer

Tertiary lymphoid structures (TLSs) provide an immunological antineoplastic effect. Recent evidences link a unique 12-chemokine (CCL2, -3, -4, -5, -8, -18, -19, -21, CXCL9, -10, -11, -13) signature status from tumor tissue and the TLS expression. However, the potential significance of 12-chemokine signature status for clinical use is unknown. We aimed to evaluate the association of 12-chemokine signature status with patient outcomes in colorectal cancer (CRC). We used integrated data of resected 975 CRC cases within three independent cohorts from France, Japan and the United States (GSE39582, KUMAMOTO from Kumamoto university hospital and TCGA). The association of 12-chemokine signature status with clinicopathological features, patient outcome, TLS expression status and key tumor molecular features was analyzed. Patients with low 12-chemokine signature status had a significant shorter relapse-free survival in discovery cohort (HR: 1.61, 95% CI: 1.11-2.39, p = 0.0123), which was confirmed in validation cohort (HR: 3.31, 95% CI: 1.33-10.08, p = 0.0087). High 12-chemokine signature status had significant associations with right-sided tumor, high tumor-localized TLS expression, BRAF mutant, CIMP-high status and MSI-high status. Furthermore, RNA-seq based analysis showed that high 12-chemokine signature status was strongly associated with inflammation-related, immune cells-related and apoptosis pathways (using gene set enrichment analysis), and more tumor-infiltrating immune cells, such as cytotoxic T lymphocytes and myeloid dendritic cells (using MCP-counter analysis). We investigated a promising effect of 12-chemokine signature status in CRC patients who underwent resection. Our data may be helpful in developing novel immunological treatment strategies for CRC.

Early Hepatic Lesions Display Immature Tertiary Lymphoid Structures and Show Elevated Expression of Immune Inhibitory and Immunosuppressive Molecules

PURPOSE

The impact of tertiary lymphoid structures (TLS) in hepatocellular carcinoma (HCC) progression is being extensively investigated. However, their presence during the early steps of human liver carcinogenesis remains unknown. We thus aimed to determine whether TLS are induced in preneoplastic/early hepatic lesions (EHL), and whether they are associated with a particular immune profile.

EXPERIMENTAL DESIGN

A series of 127 EHLs (low/high-grade dysplastic nodules, early HCC, and small and progressed HCC) was included in the study. TLSs were investigated by pathologic reviewing. Densities of immune cells were assessed using IHC. A subset of lesions was microdissected and gene expression profiling was performed with a custom NanoString panel.

RESULTS

Compared with surrounding cirrhotic nodules, EHL of all stages displayed increased densities of T cells, B cells, and dendritic cells. Immature TLSs were identified in 24% of EHL. Gene expression profiling identified a subset of EHL with elevated mRNA levels of various cytokines involved in immune cells' recruitment and TLS induction. This subgroup of EHL also showed overexpression of genes related to T- and B-cells' activation and antigen presentation, as well as those related to immunosuppression and immune exhaustion.

CONCLUSIONS

Local immune activation occurs in the very early steps of liver carcinogenesis; however, it may not be fully efficient and paradoxically favor immune evasion and progression to full-blown HCC. These results have implications for the development of anti-HCC chemopreventive strategies in cirrhotic patients.

The Cancer Stem Cell in Hepatocellular Carcinoma

The recognition of intra-tumoral cellular heterogeneity has given way to the concept of the cancer stem cell (CSC). According to this concept, CSCs are able to self-renew and differentiate into all of the cancer cell lineages present within the tumor, placing the CSC at the top of a hierarchical tree. The observation that these cells—in contrast to bulk tumor cells—are able to exclusively initiate new tumors, initiate metastatic spread and resist chemotherapy implies that CSCs are solely responsible for tumor recurrence and should be therapeutically targeted. Toward this end, dissecting and understanding the biology of CSCs should translate into new clinical therapeutic approaches. In this article, we review the CSC concept in cancer, with a special focus on hepatocellular carcinoma.

Existence of intratumoral tertiary lymphoid structures is associated with immune cells infiltration and predicts better prognosis in early-stage hepatocellular carcinoma

Tumor-associated tertiary lymphoid structures (TLS) play a critical role in the progression of various tumors. However, the dynamics of lymphocyte recruitment during hepatocellular carcinoma (HCC) clinical progression have not been fully elucidated. In the present study, tissue microarrays and hematoxylin-eosin staining were used to evaluate the existence and degree of TLS in HCC patients. Nine immune biomarkers in intratumoral tissues were examined by immunohistochemical staining. A total of 462 patients were recruited for the study. Kaplan-Meier analysis showed that TLS was inversely correlated with the risk of early tumor recurrence (P=0.014), whereas no association was found between TLS and overall survival. Cox regression analysis identified TLS as an independent prognostic factor for early HCC recurrence (P=0.005). In addition, TLS was associated with increased intratumoral CD3+, CD8+, CD20+, and decreased infiltration of Foxp3+ and CD68+ cells. A lower density of PD1+, TIM3+, and LAG3+ were found in TLS+ cases. Sub-analysis revealed the prognostic value of TLS on early-stage HCC (BCLC 0-A, TNM stage I-II) and HCC with solitary nodule. The validation cohort verified the prognostic value of TLS in early-stage HCC patients. These results suggest that TLS-targeted immune-modulating therapies may be a potential strategy for effective immune-mediated tumor suppression.

Cruel to Be Kind: Epithelial, Microbial, and Immune Cell Interactions in Gastrointestinal Cancers

A plethora of experimental and epidemiological evidence supports a critical role for inflammation and adaptive immunity in the onset of cancer and in shaping its response to therapy. These data are particularly robust for gastrointestinal (GI) cancers, such as those affecting the GI tract, liver, and pancreas, on which this review is focused. We propose a unifying hypothesis according to which intestinal barrier disruption is the origin of tumor-promoting inflammation that acts in conjunction with tissue-specific cancer-initiating mutations. The gut microbiota and its products impact tissue-resident and recruited myeloid cells that promote tumorigenesis through secretion of growth- and survival-promoting cytokines that act on epithelial cells, as well as fibrogenic and immunosuppressive cytokines that interfere with the proper function of adaptive antitumor immunity. Understanding these relationships should improve our ability to prevent cancer development and stimulate the immune system to eliminate existing malignancies.

Tumor immune microenvironment modulation-based drug delivery strategies for cancer immunotherapy

The past years have witnessed promising clinical feedback for anti-cancer immunotherapies, which have become one of the hot research topics; however, they are limited by poor delivery kinetics, narrow patient response profiles, and systemic side effects. To the best of our knowledge, the development of cancer is highly associated with the immune system, especially the tumor immune microenvironment (TIME). Based on the comprehensive understanding of the complexity and diversity of TIME, drug delivery strategies focused on the modulation of TIME can be of great significance for directing and improving cancer immunotherapy. This review highlights the TIME modulation in cancer immunotherapy and summarizes the versatile TIME modulation-based cancer immunotherapeutic strategies, medicative principles and accessory biotechniques for further clinical transformation. Remarkably, the recent advances of cancer immunotherapeutic drug delivery systems and future prospects of TIME modulation-based drug delivery systems for much more controlled and precise cancer immunotherapy will be emphatically discussed.

The immunobiology of hepatocellular carcinoma in humans and mice: Basic concepts and therapeutic implications

Basic and clinical studies have demonstrated the efficacy of immunotherapy, a technical and conceptual breakthrough that has revolutionised cancer treatment. Hepatocellular carcinoma (HCC), a deadly malignancy with aetiologic diversity and a chronic course, is strongly influenced by the immune system, and was recently found to partially benefit from immune-checkpoint inhibitor therapy. Notably, HCC onco-immunology depends on diverse genetic and environmental factors that together shape cancer-promoting inflammation and immune dysfunction - critical processes that control HCC malignant progression and response to therapy. Herein, we summarise the current understanding of liver and HCC onco-immunology obtained through basic studies with mouse models and clinical practice in humans. In particular, we discuss preclinical and clinical findings that implicate immunomodulation as a major factor in HCC development and explain the basis for HCC-targeting immunotherapy.

Intrahepatic immune changes after hepatitis c virus eradication by direct-acting antiviral therapy

BACKGROUND & AIMS

The recent approval of direct acting anti-virals (DAA) has dramatically changed the landscape of hepatitis C virus (HCV) therapy. Whether viral clearance could promote liver carcinogenesis is debated. It has been hypothesized that changes in intrahepatic immune surveillance following viral cure could favour tumour growth. This study aimed at characterizing the intrahepatic immune changes induced by HCV cure following DAA therapy.

METHODS

Patients with compensated cirrhosis who underwent surgical resection for hepatocellular carcinoma (HCC) after sustained virological response (SVR) to DAA therapy were included. A control group of untreated HCV-infected patients with compensated cirrhosis was selected. RNA was extracted from tumoral and non-tumoral tissues and analysed using the Nanostring Immuno-Oncology-360 panel. Immune cells were quantified by immunohistochemistry.

RESULTS

Twenty patients were included: 10 patients with a DAA-induced SVR and 10 untreated controls. All of them had a de novo BCLC 0/A HCC. Non-tumoral tissue profiling showed down-regulation of interferon-related genes (including MX1, ISG15 and IFIT1) after DAA therapy. No other differences in immune profiles/immune cell densities were identified between the two groups. The intra-tumoral immune profiles of HCCs that occurred after DAA therapy were not qualitatively or quantitatively different from those of tumours occurring in untreated patients.

CONCLUSION

In conclusion, removal of HCV infection after DAA-based therapy results only in a down-regulation of interferon-stimulated genes in non-tumoral tissues from patients with cirrhosis who develop HCC. These minor changes in the liver immune microenvironment are unlikely to favour HCC occurrence or recurrence after DAA-induced SVR.

The balance between breast cancer and the immune system: Challenges for prognosis and clinical benefit from immunotherapies

Cancer evolution is a complex process influenced by genetic factors and extracellular stimuli that trigger signaling pathways to coordinate the continuous and dynamic interaction between tumor cells and the elements of the immune system. For over 20 years now, the immune mechanisms controlling cancer progression have been the focus of intensive research. It is well established that the immune system conveys protective antitumor immunity by destroying immunogenic tumor variants, but also facilitates tumor progression by shaping tumor immunogenicity in a process called "immunoediting". It is also clear that immune-guided tumor editing is associated with tumor evasion from immune surveillance and therefore reinforcing the endogenous antitumor immunity is a desired goal in the context of cancer therapies. The tumor microenvironment (TME) is a complex network which consists of various cell types and factors having important roles regarding tumor development and progression. Tumor infiltrating lymphocytes (TILs) and other tumor infiltrating immune cells (TIICs) are key to our understanding of tumor immune surveillance based on tumor immunogenicity, whereby the densities and location of TILs and TIICs in the tumor regions, as well as their functional programs (comprising the "immunoscore") have a prominent role for prognosis and prediction for several cancers. The presence of tertiary lymphoid structures (TLS) in the TME or in peritumoral areas has an influence on the locally produced antitumor immune response, and therefore also has a significant prognostic impact. The cross-talk between elements of the immune system with tumor cells in the TME is greatly influenced by hypoxia, the gut and/or the local microbiota, and several metabolic elements, which, in a dynamic interplay, have a crucial role for tumor cell heterogeneity and reprogramming of immune cells along their activation and differentiation pathways. Taking into consideration the recent clinical success with the application immunotherapies for the treatment of several cancer types, increasing endeavors have been made to gain better insights into the mechanisms underlying phenotypic and metabolic profiles in the context of tumor progression and immunotherapy. In this review we will address (i) the role of TILs, TIICs and TLS in breast cancer (BCa); (ii) the different metabolic-based pathways used by immune and breast cancer cells; and (iii) implications for immunotherapy-based strategies in BCa.

Pas de Deux: Control of Anti-tumor Immunity by Cancer-Associated Inflammation

In many settings, tumor-associated inflammation, supported mainly by innate immune cells, contributes to tumor growth. Initial innate activation triggers secretion of inflammatory, regenerative, and anti-inflammatory cytokines, which in turn shape the adaptive immune response to the tumor. Here, we review the current understanding of the intricate dialog between cancer-associated inflammation and anti-tumor immunity. We discuss the changing nature of these interactions during tumor progression and the impact of the tissue environment on the anti-tumor immune response. In this context, we outline important gaps in current understanding by considering basic research and findings in the clinic. The future of cancer immunotherapy and its utility depend on improved understanding of these interactions and the ability to manipulate them in a predictable and beneficial manner.

Mouse Models for Immunotherapy in Hepatocellular Carcinoma

Liver cancer is one of the dominant causes of cancer-related mortality, and the survival rate of liver cancer is among the lowest for all cancers. Immunotherapy for hepatocellular carcinoma (HCC) has yielded some encouraging results, but the percentage of patients responding to single-agent therapies remains low. Therefore, potential directions for improved immunotherapies include identifying new immune targets and checkpoints and customizing treatment procedures for individual patients. The development of combination therapies for HCC is also crucial and urgent and, thus, further studies are required. Mice have been utilized in immunotherapy research due to several advantages, for example, being low in cost, having high success rates for inducing tumor growth, and so on. Moreover, immune-competent mice are used in immunotherapy research to clarify the role that the immune system plays in cancer growth. In this review paper, the advantages and disadvantages of mouse models for immunotherapy, the equipment that are used for monitoring HCC, and the cell strains used for inducing HCC are reviewed.

An Immune Gene Expression Signature Associated With Development of Human Hepatocellular Carcinoma Identifies Mice That Respond to Chemopreventive Agents

BACKGROUND & AIMS

Cirrhosis and chronic inflammation precede development of hepatocellular carcinoma (HCC) in approximately 80% of cases. We investigated immune-related gene expression patterns in liver tissues surrounding early-stage HCCs and chemopreventive agents that might alter these patterns to prevent liver tumorigenesis.

METHODS

We analyzed gene expression profiles of nontumor liver tissues from 392 patients with early-stage HCC (training set, N = 167 and validation set, N = 225) and liver tissue from patients with cirrhosis without HCC (N = 216, controls) to identify changes in expression of genes that regulate the immune response that could contribute to hepatocarcinogenesis. We defined 172 genes as markers for this deregulated immune response, which we called the immune-mediated cancer field (ICF). We analyzed the expression data of liver tissues from 216 patients with cirrhosis without HCC and investigated the association between this gene expression signature and development of HCC and outcomes of patients (median follow-up, 10 years). Human liver tissues were also analyzed by histology. C57BL/6J mice were given a single injection of diethylnitrosamine (DEN) followed by weekly doses of carbon tetrachloride to induce liver fibrosis and tumorigenesis. Mice were then orally given the multiple tyrosine inhibitor nintedanib or vehicle (controls); liver tissues were collected and histology, transcriptome, and protein analyses were performed. We also analyzed transcriptomes of liver tissues collected from mice on a choline-deficient high-fat diet, which developed chronic liver inflammation and tumors, orally given aspirin and clopidogrel or the anti-inflammatory agent sulindac vs mice on a chow (control) diet.

RESULTS

We found the ICF gene expression pattern in 50% of liver tissues from patients with cirrhosis without HCC and in 60% of nontumor liver tissues from patients with early-stage HCC. The liver tissues with the ICF gene expression pattern had 3 different features: increased numbers of effector T cells; increased expression of genes that suppress the immune response and activation of transforming growth factor β signaling; or expression of genes that promote inflammation and activation of interferon gamma signaling. Patients with cirrhosis and liver tissues with the immunosuppressive profile (10% of cases) had a higher risk of HCC (hazard ratio, 2.41; 95% confidence interval, 1.21-4.80). Mice with chemically induced fibrosis or diet-induced steatohepatitis given nintedanib or aspirin and clopidogrel down-regulated the ICF gene expression pattern in liver and developed fewer and smaller tumors than mice given vehicle.

CONCLUSIONS

We identified an immune-related gene expression pattern in liver tissues of patients with early-stage HCC, called the ICF, that is associated with risk of HCC development in patients with cirrhosis. Administration of nintedanib or aspirin and clopidogrel to mice with chronic liver inflammation caused loss of this gene expression pattern and development of fewer and smaller liver tumors. Agents that alter immune regulatory gene expression patterns associated with carcinogenesis might be tested as chemopreventive agents in patients with cirrhosis.

The prognostic significance of peritumoral tertiary lymphoid structures in breast cancer

Tumors and their surrounding area represent spatially organized "ecosystems", where tumor cells and the immune contextures of the different compartments are in a dynamic interplay, with potential clinical impact. Here, we aimed to investigate the prognostic significance of peritumoral tertiary lymphoid structures (TLS) either alone or jointly with the intratumoral densities and spatial distribution of CD8 + and CD163 + cells in breast cancer (BCa) patients. TLS were identified peritumorally, within the area distancing up to 5 mm from the infiltrative tumor border, counted and further characterized as adjacent or distal, in formalin-fixed, paraffin-embedded tumor tissue samples from a cohort of 167 patients, with histologically confirmed invasive ductal BCa. TLS and tumor-infiltrating immune cells were determined by H&E and immunohistochemistry. Clinical follow-up was available for 112 of these patients. Patients with peritumoral TLS exhibited worse disease-free survival (DFS) and overall survival (OS) as compared to patients lacking TLS. Moreover, the density of peritumoral TLS was found to be crucial for prognosis, since patients with abundant TLS exhibited the worst DFS and OS. By combining the density of adjacent TLS (aTLS) with our recently published intratumoral signatures based on the differential distribution of CD8 + and CD163 + in the tumor center and invasive margin, we created two improved immune signatures with superior prognostic strength and higher patient population coverage. Our observations strengthen the notion for the fundamental role of the dynamic interplay between the immune cells within the tumor microenvironment (center/invasive margin) and the tumor surrounding area (peritumoral TLS) on the clinical outcome of BCa patients.

An IKK/NF-κB Activation/p53 Deletion Sequence Drives Liver Carcinogenesis and Tumor Differentiation

Background: Most liver tumors arise on the basis of chronic liver diseases that trigger inflammatory responses. Besides inflammation, subsequent defects in the p53-signaling pathway frequently occurs in liver cancer. In this study, we analyzed the consequences of inflammation and p53 loss in liver carcinogenesis. Methods: We used inducible liver-specific transgenic mouse strains to analyze the consequences of NF-κB/p65 activation mimicking chronic inflammation and subsequent p53 loss. Results: Ikk2^ca driven NF-κB/p65 activation in mice results in liver fibrosis, the formation of ectopic lymphoid structures and carcinogenesis independent of p53 expression. Subsequent deletion of Trp53 led to an increased tumor formation, metastasis and a shift in tumor differentiation towards intrahepatic cholangiocarcinoma. In addition, loss of Trp53 in an inflammatory liver resulted in elevated chromosomal instability and indicated a distinct aberration pattern. Conclusions: In conclusion, activation of NF-κB/p65 mimicking chronic inflammation provokes the formation of liver carcinoma. Collateral disruption of Trp53 supports tumor progression and influences tumor differentiation and heterogeneity.

Conceptual Development of Immunotherapeutic Approaches to Gastrointestinal Cancer

Gastrointestinal (GI) cancer is one of the common causes of cancer-related death worldwide. Chemotherapy and/or immunotherapy are the current treatments, but some patients do not derive clinical benefits. Recently, studies from cancer molecular subtyping have revealed that tumor molecular biomarkers may predict the immunotherapeutic response of GI cancer patients. However, the therapeutic response of patients selected by the predictive biomarkers is suboptimal. The tumor immune-microenvironment apparently plays a key role in modulating these molecular-determinant predictive biomarkers. Therefore, an understanding of the development and recent advances in immunotherapeutic pharmacological intervention targeting tumor immune-microenvironments and their potential predictive biomarkers will be helpful to strengthen patient immunotherapeutic efficacy. The current review focuses on an understanding of how the host-microenvironment interactions and the predictive biomarkers can determine the efficacy of immune checkpoint inhibitors. The contribution of environmental pathogens and host immunity to GI cancer is summarized. A discussion regarding the clinical evidence of predictive biomarkers for clinical trial therapy design, current immunotherapeutic strategies, and the outcomes to GI cancer patients are highlighted. An understanding of the underlying mechanism can predict the immunotherapeutic efficacy and facilitate the future development of personalized therapeutic strategies targeting GI cancers.

The Crohn's-Like Lymphoid Reaction to Colorectal Cancer-Tertiary Lymphoid Structures With Immunologic and Potentially Therapeutic Relevance in Colorectal Cancer

The Crohn's-like lymphoid reaction (CLR) to colorectal cancer (CRC), a CRC-specific ectopic lymphoid reaction, is thought to play an important role in the host response to CRC. CLR is characterized by peritumoral lymphocytic aggregates that are found at the advancing edge of the tumor. Spatial and molecular characterization of CLR within the tumor microenvironment (TME) have uncovered a spectrum of peritumoral lymphoid aggregates with varying levels of organization and maturation. In early stages of CLR development, CD4+ T-cells cluster predominantly with mature antigen presenting dendritic cells. As CLR matures, increasing numbers of B-cells, as well as follicular dendritic cells are recruited to create lymphoid follicles. When highly organized, CLR resembles functional tertiary lymphoid structures (TLS), allowing for lymphocyte recruitment to the TME and promoting a tumor-specific adaptive immune response. CLR has been consistently associated with favorable prognostic factors and improved survival among CRC patients, often providing more prognostic information than current clinical staging systems. However, consensus is lacking regarding CLR scoring and it is not clinically assessed or reported. Differences between CLR and other cancer-associated lymphoid structures exist both in primary and metastatic disease, underscoring the need to characterize organ-specific TLS. Further research is needed to explore the role of CLR in predicting response to immunotherapy and to leverage CLR to promote immunotherapeutic strategies in CRC.

Context-Dependent Role of NF-κB Signaling in Primary Liver Cancer-from Tumor Development to Therapeutic Implications

Chronic inflammatory cell death is a major risk factor for the development of diverse cancers including liver cancer. Herein, disruption of the hepatic microenvironment as well as the immune cell composition are major determinants of malignant transformation and progression in hepatocellular carcinomas (HCC). Considerable research efforts have focused on the identification of predisposing factors that promote induction of an oncogenic field effect within the inflammatory liver microenvironment. Among the most prominent factors involved in this so-called inflammation-fibrosis-cancer axis is the NF-κB pathway. The dominant role of this pathway for malignant transformation and progression in HCC is well documented. Pathway activation is significantly linked to poor prognostic traits as well as stemness characteristics, which places modulation of NF-κB signaling in the focus of therapeutic interventions. However, it is well recognized that the mechanistic importance of the pathway for HCC is highly context and cell type dependent. While constitutive pathway activation in an inflammatory etiological background can significantly promote HCC development and progression, absence of NF-κB signaling in differentiated liver cells also significantly enhances liver cancer development. Thus, therapeutic targeting of NF-κB as well as associated family members may not only exert beneficial effects but also negatively impact viability of healthy hepatocytes and/or cholangiocytes, respectively. The review presented here aims to decipher the complexity and paradoxical functions of NF-κB signaling in primary liver and non-parenchymal cells, as well as the induced molecular alterations that drive HCC development and progression with a particular focus on (immune-) therapeutic interventions.

Rejuvenation: Turning back the clock of aging kidney

Aging is inevitable in life. It is defined as impaired adaptive capacity to environmental or internal stresses with growing rates of disease and death. Aging is also an important risk factor for various kidney diseases such as acute kidney injury and chronic kidney disease. Patients older than 65 years have nearly 28% risk of failing recovery of kidney function when suffering from acute kidney injury. It is reported that more than a third of population aged 65 years and older have chronic kidney disease in Taiwan, and the occurrence of multiple age-related disorders is predicted to increase in parallel. Renal aging is a complex, multifactorial process characterized by many anatomical and functional changes. Several factors are involved in renal aging, such as loss of telomeres, cell cycle arrest, chronic inflammation, activation of renin-angiotensin system, decreased klotho expression, and development of tertiary lymphoid tissues. These changes can also be observed in many other different types of renal injury. Recent studies suggested that young blood may rejuvenate aged organs, including the kidneys. In order to develop new therapeutic strategies for renal aging, the mechanisms underlying renal aging and by which young blood can halt or reverse aging process warrants further study.

Tertiary lymphoid structures in the era of cancer immunotherapy

Tertiary lymphoid structures (TLSs) are ectopic lymphoid organs that develop in non-lymphoid tissues at sites of chronic inflammation including tumours. Key common characteristics between secondary lymphoid organogenesis and TLS neogenesis have been identified. TLSs exist under different maturation states in tumours, culminating in germinal centre formation. The mechanisms that underlie the role of TLSs in the adaptive antitumour immune response are being deciphered. The description of the correlation between TLS presence and clinical benefit in patients with cancer, suggesting that TLSs could be a prognostic and predictive factor, has drawn strong interest into investigating the role of TLSs in tumours. A current major challenge is to exploit TLSs to promote lymphocyte infiltration, activation by tumour antigens and differentiation to increase the antitumour immune response. Several approaches are being developed using chemokines, cytokines, antibodies, antigen-presenting cells or synthetic scaffolds to induce TLS formation. Strategies aiming to induce TLS neogenesis in immune-low tumours and in immune-high tumours, in this case, in combination with therapeutic agents dampening the inflammatory environment and/or with immune checkpoint inhibitors, represent promising avenues for cancer treatment.

Hepatocellular Carcinoma Risk Stratification by Genetic Profiling in Patients with Cirrhosis

Prediction of future hepatocellular carcinoma (HCC) risk in the sizable chronic liver disease population is an urgent unmet need to enable regular HCC screening for early detection. Germline deoxyribonucleic acid polymorphisms likely represent etiology-specific host factors that determine HCC susceptibility, including single nucleotide polymorphisms in EGF, IFNL3, MICA, and TLL1 in hepatitis C with or without active viral infection, and PNPLA3, TM6SF2, and MBOAT7 in metabolic liver diseases. Transcriptome-based prognostic liver signature in diseased liver tissue has been associated with long-term HCC risk in viral and metabolic etiologies. Transcriptomic signatures of hepatic injury and specific cell type such as aggregated lymphocytes also predict HCC development. Circulating factors such as proteins and their chemical modification, nucleotides, and metabolites may serve for less-invasive assessment of short- or long-term HCC risk. These biomarkers will enable individual HCC risk-based personalized clinical management for cost-effective early HCC detection and improvement of patient survival.

Natural Killer Cell-Derived Interferon-Gamma Promotes Hepatocellular Carcinoma Through the Epithelial Cell Adhesion Molecule-Epithelial-to-Mesenchymal Transition Axis in Hepatitis B Virus Transgenic Mice

Hepatitis B virus (HBV) is a major risk factor for development of hepatocellular carcinoma (HCC), at least partially due to dysfunctional anti-HBV adaptive immunity; however, the role of innate immune response to HBV in this process is not well understood. In this study, low-dose polyinosinic:polycytidylic acid (poly [I:C]), a natural killer (NK) cell activator (3 μg/g body weight, twice/week for 8 weeks), induced HCC in HBV transgenic (HBs-Tg) mice, with an incidence of 100% after 6 months, while HBs-Tg mice without treatment only had HCC with an incidence of 16.7%. In HBs-Tg mice, poly (I:C) induced liver inflammation with markedly increased infiltrating lymphocytes, along with the concurrently increased apoptosis and proliferation of hepatocytes, leading to the accelerated epithelial-to-mesenchymal transition (EMT) of hepatocytes shown by increased expression of the typical transcriptional factors (Slug, Twist, and mothers against decapentaplegic-interacting protein 1) and phenotypic proteins (vimentin and chemokine [C-X-C motif] receptor 4). The EMT and tumorigenesis in this model depended on the presence of NK cells because depletion of these cells significantly reduced the HCC rate to 28.6%. Further, intrahepatic NK cells highly expressed interferon-gamma (IFN-γ), anti-IFN-γ neutralizing monoclonal antibody might obviously alleviate the hepatitis, and hepatocyte-specific IFN-γ overexpression promoted HCC. Moreover, IFN-γ deficiency in HBs-Tg mice prevented HCC occurring, though hepatic NK cells existed and could be activated, suggesting the critical role of IFN-γ in NK cell-mediated tumorigenesis. In an in vitro experiment, IFN-γ up-regulated epithelial cell adhesion molecule (EpCAM) expression through phosphorylated signal transducer and activator of transcription (p-STAT1) pathway, which was followed by EMT, and p-STAT1 inhibitor might absolutely abolish the expression of EpCAM and EMT in HBV surface antigen-positive hepatocytes. Conclusion: This work demonstrates that NK cell-derived IFN-γ promotes HCC through the EpCAM-EMT axis in HBs-Tg mice, revealing the importance of innate immunity in pathogenesis of HBV-associated HCC.

Redefining Chronic Inflammation in Aging and Age-Related Diseases: Proposal of the Senoinflammation Concept

Age-associated chronic inflammation is characterized by unresolved and uncontrolled inflammation with multivariable low-grade, chronic and systemic responses that exacerbate the aging process and age-related chronic diseases. Currently, there are two major hypotheses related to the involvement of chronic inflammation in the aging process: molecular inflammation of aging and inflammaging. However, neither of these hypotheses satisfactorily addresses age-related chronic inflammation, considering the recent advances that have been made in inflammation research. A more comprehensive view of age-related inflammation, that has a scope beyond the conventional view, is therefore required. In this review, we discuss newly emerging data on multi-phase inflammatory networks and proinflammatory pathways as they relate to aging. We describe the age-related upregulation of nuclear factor (NF)-κB signaling, cytokines/chemokines, endoplasmic reticulum (ER) stress, inflammasome, and lipid accumulation. The later sections of this review present our expanded view of age-related senescent inflammation, a process we term "senoinflammation", that we propose here as a novel concept. As described in the discussion, senoinflammation provides a schema highlighting the important and ever-increasing roles of proinflammatory senescence-associated secretome, inflammasome, ER stress, TLRs, and microRNAs, which support the senoinflammation concept. It is hoped that this new concept of senoinflammation opens wider and deeper avenues for basic inflammation research and provides new insights into the anti-inflammatory therapeutic strategies targeting the multiple proinflammatory pathways and mediators and mediators that underlie the pathophysiological aging process.

APC germline hepatoblastomas demonstrate cisplatin-induced intratumor tertiary lymphoid structures

Hepatoblastoma (HB) is the most common liver cancer in children. We aimed to characterize HB related to APC (Adenomatous Polyposis Coli) germline mutation (APC-HB). This French multicentric retrospective study included 12 APC-HB patients under 5 at diagnosis. Clinical features of APC-HB were compared to the French SIOPEL2-3 cohort of HB patients. Molecular and histopathological analyses of APC-HB were compared to 15 consecutive sporadic HB treated at Bicêtre hospital from 2013 to 2015 (non-APC-HB). APC-HB patients have a peculiar spectrum of germline APC mutations, with no events in the main hotspot of classical APC mutations at codon 1309 (P < .05). Compared to sporadic HB, they have similar clinical features including good prognosis since all patients are alive in complete remission at last follow-up. APC-HB are mostly well-limited tumors with fetal predominance and few mesenchymal components. All APC-HB have an activated Wnt/β-catenin pathway without CTNNB1 mutation, confirming that germline APC and somatic CTNNB1 mutations are mutually exclusive (P < .001). Pathological reviewing identified massive intratumor tertiary lymphoid structures (TLS) containing both lymphocytes and antigen-presenting cells in all 11 APC-HB cases who received cisplatin-based neoadjuvant chemotherapy but not in five pre-chemotherapy samples (four paired biopsies and one patient resected without chemotherapy), indicating that these TLS are induced by chemotherapy (P < .001). Conclusion: APC-HB show a good prognosis, they are all infiltrated by cisplatin-induced TLS, a feature only retrieved in a minority of non-APC-HB. This suggests that APC inactivation can synergize with cisplatin to induce an immunogenic cell death that initiates an anti-tumor immune response.

Development and Organization of the Secondary and Tertiary Lymphoid Organs: Influence of Microbial and Food Antigens

Background:

Secondary lymphoid organs (SLO) are distributed in many districts of the body and, especially, lymph nodes, spleen and gut-associated lymphoid tissue are the main cellular sites. On the other hand, tertiary lymphoid organs (TLO) are formed in response to inflammatory, infectious, autoimmune and neoplastic events. </P><P> Developmental Studies: In the present review, emphasis will be placed on the developmental differences of SLO and TLO between small intestine and colon and on the role played by various chemokines and cell receptors. Undoubtedly, microbiota is indispensable for the formation of SLO and its absence leads to their poor formation, thus indicating its strict interaction with immune and non immune host cells. Furthermore, food antigens (for example, tryptophan derivatives, flavonoids and byphenils) bind the aryl hydrocarbon receptor on innate lymphoid cells (ILCs), thus promoting the development of postnatal lymphoid tissues. Also retinoic acid, a metabolite of vitamin A, contributes to SLO development during embryogenesis. Vitamin A deficiency seems to account for reduction of ILCs and scarce formation of solitary lymphoid tissue. </P><P> Translational Studies: The role of lymphoid organs with special reference to intestinal TLO in the course of experimental and human disease will also be discussed. </P><P> Future Perspectives: Finally, a new methodology, the so-called “gut-in-a dish”, which has facilitated the in vitro interaction study between microbe and intestinal immune cells, will be described.

Inflammation and Liver Cancer: Molecular Mechanisms and Therapeutic Targets

Hepatocellular carcinoma (HCC) is associated with chronic inflammation and fibrosis arising from different etiologies, including hepatitis B and C and alcoholic and nonalcoholic fatty liver diseases. The inflammatory cytokines tumor necrosis factor-α and interleukin-6 and their downstream targets nuclear factor kappa B (NF-κB), c-Jun N-terminal kinase (JNK), and signal transducer and activator of transcription 3 drive inflammation-associated HCC. Further, while adaptive immunity promotes immune surveillance to eradicate early HCC, adaptive immune cells, such as CD8+ T cells, Th17 cells, and B cells, can also stimulate HCC development. Thus, the role of the hepatic immune system in HCC development is a highly complex topic. This review highlights the role of cytokine signals, NF-κB, JNK, innate and adaptive immunity, and hepatic stellate cells in HCC and discusses whether these pathways could be therapeutic targets. The authors will also discuss cholangiocarcinoma and liver metastasis because biliary inflammation and tumor-associated stroma are essential for cholangiocarcinoma development and because primary tumor-derived inflammatory mediators promote the formation of a "premetastasis niche" in the liver.

Evaluation of Post-transcriptional Gene Regulation in Pancreatic Cancer Cells: Studying RNA Binding Proteins and Their mRNA Targets

Post-transcriptional regulation of gene expression through interaction between RNA binding proteins (RBPs) and target mRNAs have gained considerable interest over the last decade. Altered expression of RBPs as detected in pancreatic ductal adenocarcinoma (PDAC) cells alters mRNA processing, and in turn, the entire transcriptome and proteome. Thus, this gene regulatory mechanism can regulate important pro-oncogenic signaling pathways (e.g., TP53, WEE1, and c-MYC) in PDAC cells. Ribonucleoprotein immunoprecipitation assays (RNP-IP or RIP) are a modified immunoprecipitation method to study physical interactions between RBPs and their mRNA targets. As a first step to explore RBP interactomes and define novel therapeutic targets and dysregulated pathways in disease, RIPs are a sensitive and established molecular biology technique used to isolate and differentiate bound transcripts to RBPs in a variety of experimental conditions. This chapter describes an up-to-date, detailed protocol for performing this assay in mammalian cytoplasmic extracts (i.e., PDAC cells), and reviews current methods to validate target binding sites such as electrophoretic mobility shift assay (EMSA) and cross-linking immunoprecipitation polymerase chain reaction (CLIP-PCR).

Intra-tumoral tertiary lymphoid structures are associated with a low risk of early recurrence of hepatocellular carcinoma

BACKGROUND & AIMS

Tertiary lymphoid structures (TLSs) provide a local and critical microenvironment for generating anti-tumor cellular and humoral immune responses. TLSs are associated with improved clinical outcomes in most solid tumors investigated to date. However, their role in hepatocellular carcinoma (HCC) is debated, as they have recently been shown to promote the growth of malignant hepatocyte progenitors in the non-tumoral liver.

METHODS

We aimed to determine, by pathological review, the prognostic significance of both intra-tumoral and non-tumoral TLSs in a series of 273 patients with HCC treated by surgical resection in Henri Mondor University Hospital. Findings were further validated by gene expression profiling using a public data set (LCI cohort).

RESULTS

TLSs were identified in 47% of the tumors, by pathological review, with lymphoid aggregates, primary and secondary follicles in 26%, 16% and 5% of the cases, respectively. Univariate and multivariate analyses showed that intra-tumoral TLSs significantly correlated with a lower risk of early relapse (<2 years after surgery, hazard ratio 0.46, p = 0.005). Interestingly, the risk of recurrence was also related to the degree of TLS maturation (primary or secondary follicles vs. lymphoid aggregates, p = 0.01). A gene expression signature associated with the presence of intra-tumoral TLS was also independently associated with a lower risk of early relapse in the LCI cohort. No association between the density of TLSs located in the adjacent non-tumoral liver and early or late recurrence was observed.

CONCLUSIONS

We have shown that intra-tumoral TLSs are associated with a lower risk of early relapse in 2 independent cohorts of patients with HCC treated by surgical resection. Thus, intra-tumoral TLSs may reflect the existence of ongoing, effective anti-tumor immunity.

LAY SUMMARY

Tertiary lymphoid structures provide a critical microenvironment for generating anti-tumor immune responses, and are associated with improved clinical outcome in most cancers investigated. Their role in hepatocellular carcinoma is however debated. We show in the present study that intra-tumoral tertiary lymphoid structures are associated with a low risk of early relapse after surgical resection, suggesting that they reflect the existence of in situ, effective anti-tumor immunity.

Lect2 Controls Inflammatory Monocytes to Constrain the Growth and Progression of Hepatocellular Carcinoma

Leukocyte cell-derived chemotaxin-2 (LECT2) was originally identified as a hepatocyte-secreted chemokine-like factor and a positive target of β-catenin signaling. Here, we dissected out the mechanisms by which LECT2 modulates hepatocellular carcinoma (HCC) development using both HCC mouse models and human HCC samples. We have demonstrated that LECT2 exhibits dual abilities as it has profound repercussions on the tumor phenotype itself and the immune microenvironment. Its absence confers Ctnnb-1-mutated tumor hepatocytes a stronger ability to undergo epithelial to mesenchymal transition and fosters the accumulation of pejorative inflammatory monocytes harboring immunosuppressive properties and strong tumor-promoting potential. Consistent with our HCC mouse model, a low level of LECT2 in human HCC is strongly associated with high tumor grade and the presence of inflammatory infiltrates, emphasizing the clinical value of LECT2 in human liver tumorigenesis. Conclusion: Our findings have demonstrated that LECT2 is a key player in liver tumorigenesis because its absence reshapes the tumor microenvironment and the tumor phenotype, revealing LECT2 as a promising immunotherapeutic option for HCC.

A novel spontaneous hepatocellular carcinoma mouse model for studying T-cell exhaustion in the tumor microenvironment

Immunotherapy has ushered in a new era of cancer therapy, and this is also applicable to therapy of hepatocellular carcinoma (HCC). In this context, effective development of therapeutic strategies requires an HCC mouse model with known tumor-associated antigens (TAAs) and an HCC growth reporter. We created such a model using hydrodynamic injection and a transposon system to introduce AKT and NRAS and open reading frames (ORFs) encoding surrogate tumor antigens and luciferase into chromosomes of hepatocytes to induce nodular and diffuse tumors in the liver. TAA-specific CD8⁺ T cells were detected during HCC progression; however, these showed exhausted-like phenotypes and were unable to control tumor growth. Myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAM) from the tumor microenvironment were found to contribute to the suppression of the CD8⁺ T-cell response. The transposon-based Akt/N-Ras-induced HCC mouse model we developed enables researchers to monitor tumor growth non-invasively and to quantify and characterize endogenous or adoptively transferred TAA-specific CD8⁺ T-cell responses. These features make it a suitable preclinical model for exploration and evaluation of immune checkpoint inhibitors and cell-based immunotherapies for HCC treatment.

microRNA 193a-5p Regulates Levels of Nucleolar- and Spindle-Associated Protein 1 to Suppress Hepatocarcinogenesis

BACKGROUND & AIMS

We performed an integrated analysis to identify microRNAs (miRNAs) and messenger RNAs (mRNAs) with altered expression in liver tumors from 3 mouse models of hepatocellular carcinoma (HCC) and human tumor tissues.

METHODS

We analyzed miRNA and mRNA expression profiles of liver tissues from mice with diethylnitrosamine-induced hepatocarcinogenesis, conditional expression of lymphotoxin alpha and lymphotoxin beta, or inducible expression of a Myc transgene (Tet-O-Myc mice), as well as male C57BL/6 mice (controls). miRNA mimics were expressed and miRNAs and mRNAs were knocked down in human (Huh7, Hep3B, JHH2) hepatoma cell lines; cells were analyzed for viability, proliferation, apoptosis, migration, and invasion. Cells were grown as xenograft tumors in nude mice and analyzed. We combined in silico target gene prediction with mRNA profiles from all 3 mouse models. We quantified miRNA levels in 146 fresh-frozen tissues from patients (125 HCCs, 17 matched nontumor tissues, and 4 liver samples from patients without cancer) and published human data sets and tested correlations with patient survival times using Kaplan-Meier curves and the log-rank test. Levels of NUSAP1 mRNA were quantified in 237 HCCs and 5 nontumor liver samples using the TaqMan assay.

RESULTS

Levels of the miRNA 193a-5p (MIR193A-5p) were reduced in liver tumors from all 3 mouse tumor models and in human HCC samples, compared with nontumor liver tissues. Expression of a MIR193A-5p mimic in hepatoma cells reduced proliferation, survival, migration, and invasion and their growth as xenograft tumors in nude mice. We found nucleolar and spindle-associated protein 1 (NUSAP1) to be a target of MIR193A-5p; HCC cells and tissues with low levels of MIR193A-5p had increased expression of NUSAP1. Increased levels of NUSAP1 in HCC samples correlated with shorter survival times of patients. Knockdown of NUSAP1 in Huh7 cells reduced proliferation, survival, migration, and growth as xenograft tumors in nude mice. Hydrodynamic tail-vein injections of a small hairpin RNA against NUSAP1 reduced growth of Akt1-Myc-induced tumors in mice.

CONCLUSIONS

MIR193A-5p appears to prevent liver tumorigenesis by reducing levels of NUSAP1. Levels of MIR193A-5p are reduced in mouse and human HCC cells and tissues, leading to increased levels of NUSAP1, associated with shorter survival times of patients. Integrated analyses of miRNAs and mRNAs in tumors from mouse models can lead to identification of therapeutic targets in humans. The currently reported miRNA and mRNA profiling data have been submitted to the Gene Expression Omnibus (super-series accession number GSE102418).

Obesity Drives STAT-1-Dependent NASH and STAT-3-Dependent HCC

Obesity is a major driver of cancer, especially hepatocellular carcinoma (HCC). The prevailing view is that non-alcoholic steatohepatitis (NASH) and fibrosis or cirrhosis are required for HCC in obesity. Here, we report that NASH and fibrosis and HCC in obesity can be dissociated. We show that the oxidative hepatic environment in obesity inactivates the STAT-1 and STAT-3 phosphatase T cell protein tyrosine phosphatase (TCPTP) and increases STAT-1 and STAT-3 signaling. TCPTP deletion in hepatocytes promoted T cell recruitment and ensuing NASH and fibrosis as well as HCC in obese C57BL/6 mice that normally do not develop NASH and fibrosis or HCC. Attenuating the enhanced STAT-1 signaling prevented T cell recruitment and NASH and fibrosis but did not prevent HCC. By contrast, correcting STAT-3 signaling prevented HCC without affecting NASH and fibrosis. TCPTP-deletion in hepatocytes also markedly accelerated HCC in mice treated with a chemical carcinogen that promotes HCC without NASH and fibrosis. Our studies reveal how obesity-associated hepatic oxidative stress can independently contribute to the pathogenesis of NASH, fibrosis, and HCC.

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Obesity promotes hepatic STAT-1 and STAT-3 signaling

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Obesity promotes STAT-1-dependent T cell-infiltration, NASH, and fibrosis

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Obesity promotes NASH-independent STAT-3-dependent HCC

The Multiple Layers of the Tumor Environment

The notion of tumor microenvironment (TME) has been brought to the forefront of recent scientific literature on cancer. However, there is no consensus on how to define and spatially delineate the TME. We propose that the time is ripe to go beyond an all-encompassing list of the components of the TME, and to construct a multilayered view of cancer. We distinguish six layers of environmental interactions with the tumor and show that they are associated with distinct mechanisms, and ultimately with distinct therapeutic approaches.

Targeting IKKβ in Cancer: Challenges and Opportunities for the Therapeutic Utilisation of IKKβ Inhibitors

Deregulated NF-κB signalling is implicated in the pathogenesis of numerous human inflammatory disorders and malignancies. Consequently, the NF-κB pathway has attracted attention as an attractive therapeutic target for drug discovery. As the primary, druggable mediator of canonical NF-κB signalling the IKKβ protein kinase has been the historical focus of drug development pipelines. Thousands of compounds with activity against IKKβ have been characterised, with many demonstrating promising efficacy in pre-clinical models of cancer and inflammatory disease. However, severe on-target toxicities and other safety concerns associated with systemic IKKβ inhibition have thus far prevented the clinical approval of any IKKβ inhibitors. This review will discuss the potential reasons for the lack of clinical success of IKKβ inhibitors to date, the challenges associated with their therapeutic use, realistic opportunities for their future utilisation, and the alternative strategies to inhibit NF-κB signalling that may overcome some of the limitations associated with IKKβ inhibition.

The Paradoxical Role of NKG2D in Cancer Immunity

The activating receptor NKG2D and its ligands are recognized as a potent immune axis that controls tumor growth and microbial infections. With regards to cancer surveillance, various studies have demonstrated the antitumor function mediated by NKG2D on natural killer cells and on conventional and unconventional T cells. The use of NKG2D-deficient mice established the importance of NKG2D in delaying tumor development in transgenic mouse models of cancer. However, we recently demonstrated an unexpected, flip side to this coin, the ability for NKG2D to contribute to tumor growth in a model of inflammation-driven liver cancer. With a focus on the liver, here, we review current knowledge of NKG2D-mediated tumor surveillance and discuss evidence supporting a dual role for NKG2D in cancer immunity. We postulate that in certain advanced cancers, expression of ligands for NKG2D can drive cancer progression rather than rejection. We propose that the nature of the microenvironment within and surrounding tumors impacts the outcome of NKG2D activation. In a form of autoimmune attack, NKG2D promotes tissue damage, mostly in the inflamed tissue adjacent to the tumor, facilitating tumor progression while being ineffective at rejecting transformed cells in the tumor bed.

Immune checkpoint blockade for the treatment of human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common cancers with a high recurrence rate. Currently, tyrosine kinase inhibitors (TKIs) are the first-line treatment for cases refractory to conventional therapies. However, the acquisition of somatic mutations can result in TKI resistance. Clinical evidence suggests that acquired immunity contributes to the suppression of tumor recurrence, indicating the potential of induced antitumor immune reaction for the treatment of HCC. Recently, immune checkpoint inhibitors have become available for the treatment of malignancies. They are effective regardless of the response to prior therapies and a durable effect can be expected, which should be attributed to an adaptive immunity to HCC components. The results of phase I/II trials of nivolumab, an anti-programmed cell death-1 antibody, showed that 20% of patients showed objective response and that nivolumab was effective regardless of prior sorafenib treatment and viral status. Nivolumab received expedited Food and Drug Administration approval in 2017 for the treatment of advanced HCC after failure or intolerance to sorafenib. However, the majority of the patients remain refractory, likely due to the solid immune suppressive status, which involves many stromal cells, humoral mediators, and suppressive checkpoint molecules. Therefore, current clinical trials are focusing on how immunosuppressive conditions in HCC might be overcome using immune checkpoint inhibitors in combination with different types of immune checkpoint blockades, TKIs, and other conventional treatments. The development of immune checkpoint inhibitors is rapidly progressing and these inhibitors are likely to be key agents for HCC treatment in the near feature.

Hyperactive gp130/STAT3-driven gastric tumourigenesis promotes submucosal tertiary lymphoid structure development

Tertiary lymphoid structures (TLSs) display phenotypic and functional characteristics of secondary lymphoid organs, and often develop in tissues affected by chronic inflammation, as well as in certain inflammation-associated cancers where they are prognostic of improved patient survival. However, the mechanisms that govern the development of tumour-associated TLSs remain ill-defined. Here, we observed tumour-associated TLSs in a preclinical mouse model (gp130F/F ) of gastric cancer, where tumourigenesis is dependent on hyperactive STAT3 signalling through the common IL-6 family signalling receptor, gp130. Gastric tumourigenesis was associated with the development of B and T cell-rich submucosal lymphoid aggregates, containing CD21+ cellular networks and high endothelial venules. Temporally, TLS formation coincided with the development of gastric adenomas and induction of homeostatic chemokines including Cxcl13, Ccl19 and Ccl21. Reflecting the requirement of gp130-driven STAT3 signalling for gastric tumourigenesis, submucosal TLS development was also STAT3-dependent, but independent of the cytokine IL-17 which has been linked with lymphoid neogenesis in chronic inflammation and autoimmunity. Interestingly, upregulated lymphoid chemokine expression and TLS formation were also observed in a chronic gastritis model induced by Helicobacter felis infection. Tumour-associated TLSs were also observed in patients with intestinal-type gastric cancer, and a gene signature linked with TLS development in gp130F/F mice was associated with advanced clinical disease, but was not prognostic of patient survival. Collectively, our in vivo data reveal that hyperactive gp130-STAT3 signalling closely links gastric tumourigenesis with lymphoid neogenesis, and while a TLS gene signature was associated with advanced gastric cancer in patients, it did not indicate a favourable prognosis.

The hyaluronic acid-rich node and duct system is a structure organized for innate immunity and mediates the local inflammation

The Hyaluronic Acid-rich Node and Duct System (HAR-NDS or NDS), Primo Vascular System (PVS) or Bonghan System (BHS), is thought to be a third circulatory system independent of the blood and lymphatic systems and a structure of connected nodes and ducts. Although it seems to be part of the immune system as it is enriched with cells of innate immunity, little is known about its immunological roles. We performed cellular profiling and secretome analysis of NDS in a steady state and under TLR2- or TLR4-mediated local inflammation, and found that the NDS is pre-dominantly enriched with the myeloid cells, selectively attracts the inflammatory macrophages and neutrophils, has a flexible structure just like the lymph node, and is structured with the fibroblastic reticular cells and reticular network. NDS dominantly harbored the myeloid cells in both steady and activated status, and secreted various types of inflammatory cytokines by proinflammatory stimuli. These results suggest that NDS is the lymphoid structure for the innate immunity and plays an intermediary role in the innate immune cell-mediated local inflammation.