The Tumor Macroenvironment: Cancer-Promoting Networks Beyond Tumor Beds

MicroRNA-155 and its exosomal form: Small pieces in the gastrointestinal cancers puzzle

Gastrointestinal (GI) cancers are common cancers that are responsible for a large portion of global cancer fatalities. Due to this, there is a pressing need for innovative strategies to identify and treat GI cancers. MicroRNAs (miRNAs) are short ncRNAs that can be considered either cancer-causing or tumor-inhibiting molecules. MicroRNA-155, also known as miR-155, is a vital regulator in various cancer types. This miRNA has a carcinogenic role in a variety of gastrointestinal cancers, including pancreatic, colon, and gastric cancers. Since the abnormal production of miR-155 has been detected in various malignancies and has a correlation with increased mortality, it is a promising target for future therapeutic approaches. Moreover, exosomal miR-155 associated with tumors have significant functions in communicating between cells and establishing the microenvironment for cancer in GI cancers. Various types of genetic material, such as specifically miR-155 as well as proteins found in cancer-related exosomes, have the ability to be transmitted to other cells and have a function in the advancement of tumor. Therefore, it is critical to conduct a review that outlines the diverse functions of miR-155 in gastrointestinal malignancies. As a result, we present a current overview of the role of miR-155 in gastrointestinal cancers. Our research highlighted the role of miR-155 in GI cancers and covered critical issues in GI cancer such as pharmacologic inhibitors of miRNA-155, miRNA-155-assosiated circular RNAs, immune-related cells contain miRNA-155. Importantly, we discussed miRNA-155 in GI cancer resistance to chemotherapy, diagnosis and clinical trials. Furthermore, the function of miR-155 enclosed in exosomes that are released by cancer cells or tumor-associated macrophages is also covered.

The cross-talk between the macro and micro-environment in precursor lesions of pancreatic cancer leads to new and promising circulating biomarkers

Pancreatic cancer (PC) is a clinically challenging tumor to combat due to its advanced stage at diagnosis as well as its resistance to currently available therapies. The absence of early symptoms and known detectable biomarkers renders this disease incredibly difficult to detect/manage. Recent advances in the understanding of PC biology have highlighted the importance of cancer-immune cell interactions, not only in the tumor micro-environment but also in distant systemic sites, like the bone marrow, spleen and circulating immune cells, the so-called macro-environment. The response of the macro-environment is emerging as a determining factor in tumor development by contributing to the formation of an increasingly immunogenic micro-environment promoting tumor homeostasis and progression. We will summarize the key events associated with the feedback loop between the tumor immune micro-environment (TIME) and the tumor immune macroenvironment (TIMaE) in pancreatic precancerous lesions along with how it regulates disease development and progression. In addition, liquid biopsy biomarkers capable of diagnosing PC at an early stage of onset will also be discussed. A clearer understanding of the early crosstalk between micro-environment and macro-environment could contribute to identifying new molecular therapeutic targets and biomarkers, consequently improving early PC diagnosis and treatment.

Quantitative Proteomic Analysis Reveals Functional Alterations of the Peripheral Immune System in Colorectal Cancer

Colorectal cancer (CRC) is characterized by high morbidity, high mortality, and limited response to immunotherapies. The peripheral immune system is an important component of tumor immunity, and enhancements of peripheral immunity help to suppress tumor progression. However, the functional alterations of the peripheral immune system in CRC are unclear. Here, we used mass spectrometry-based quantitative proteomics to establish a protein expression atlas for the peripheral immune system in CRC, including plasma and five types of immune cells (CD4+ T cells, CD8+ T cells, monocytes, natural killer cells, and B cells). Synthesizing the results of the multidimensional analysis, we observed an enhanced inflammatory phenotype in CRC, including elevated expression of plasma inflammatory proteins, activation of the inflammatory pathway in monocytes, and increased inflammation-related ligand-receptor interactions. Notably, we observed tumor effects on peripheral T cells, including altered cell subpopulation ratios and suppression of cell function. Suppression of CD4+ T cell function is mainly mediated by high expression levels of protein tyrosine phosphatases. Among them, the expression of protein tyrosine phosphatase receptor type J (PTPRJ) gradually increased with CRC progression; knockdown of PTPRJ in vitro could promote T cell activation, thereby enhancing peripheral immunity. We also found that the combination of leucine-rich α-2 glycoprotein 1 (LRG1) and apolipoprotein A4 (APOA4) had the best predictive ability for colorectal cancer and has the potential to be a biomarker. Overall, this study provides a comprehensive understanding of the peripheral immune system in CRC. It also offers insights regarding the potential clinical utilities of these peripheral immune characteristics as diagnostic indicators and therapeutic targets.

From immune equilibrium to tumor ecodynamics

Objectives

There is no theory to quantitatively describe the complex tumor ecosystem. At the same time, cancer immunotherapy is considered a revolution in oncology, but the methods used to describe tumors and the criteria used to evaluate efficacy are not keeping pace. The purpose of this study is to establish a new theory for quantitatively describing the tumor ecosystem, innovating the methods of tumor characterization, and establishing new efficacy evaluation criteria for cancer immunotherapy.

Methods

Based on the mathematization of immune equilibrium theory and the establishment of immunodynamics in a previous study, the method of reverse immunodynamics was used, namely, the immune braking force was regarded as the tumor ecological force and the immune force was regarded as the tumor ecological braking force, and the concept of momentum in physics was applied to the tumor ecosystem to establish a series of tumor ecodynamic equations. These equations were used to solve the fundamental and applied problems of the complex tumor ecosystem.

Results

A series of tumor ecodynamic equations were established. The tumor ecological momentum equations and their component factors could be used to distinguish disease progression, pseudoprogression, and hyperprogression in cancer immunotherapy. On this basis, the adjusted tumor momentum equations were established to achieve the equivalence of tumor activity (including immunosuppressive activity and metabolic activity) and tumor volume, which could be used to calculate individual disease remission rate and establish new efficacy evaluation criteria (ieRECIST) for immunotherapy of solid tumor based on tumor ecodynamics. At the same time, the concept of moving cube-to-force square ratio and its expression were proposed to calculate the area under the curve of tumor ecological braking force of blood required to achieve an individual disease remission rate when the adjusted tumor ecological momentum was known.

Conclusions

A new theory termed tumor ecodynamics emphasizing both tumor activity and tumor volume is established to solve a series of basic and applied problems in the complex tumor ecosystem. It can be predicted that the future will be the era of cancer immune ecotherapy that targets the entire tumor ecosystem.

Exploring the underlying correlation between microbiota, immune system, hormones, and inflammation with breast cancer and the role of probiotics, prebiotics and postbiotics

According to recent research, bacterial imbalance in the gut microbiota and breast tissue may be linked to breast cancer. It has been discovered that alterations in the makeup and function of different types of bacteria found in the breast and gut may contribute to growth and advancement of breast cancer in several ways. The main role of gut microbiota is to control the metabolism of steroid hormones, such as estrogen, which are important in raising the risk of breast cancer, especially in women going through menopause. On the other hand, because the microbiota can influence mucosal and systemic immune responses, they are linked to the mutual interactions between cancer cells and their local environment in the breast and the gut. In this regard, the current review thoroughly explains the mode of action of probiotics and microbiota to eradicate the malignancy. Furthermore, immunomodulation by microbiota and probiotics is described with pathways of their activity.

Role of the gut microbiota in the pathogenesis of endometriosis: a review

Endometriosis is classically defined as a chronic inflammatory heterogeneous disorder occurring in any part of the body, characterized by estrogen-driven periodic bleeding, proliferation, and fibrosis of ectopic endometrial glands and stroma outside the uterus. Endometriosis can take overwhelmingly serious damage to the structure and function of multi-organ, even impair whole-body systems, resulting in severe dysmenorrhea, chronic pelvic pain, infertility, fatigue and depression in 5-10% women of reproductive age. Precisely because of a huge deficiency of cognition about underlying etiology and complex pathogenesis of the debilitating disease, early diagnosis and treatment modalities with relatively minor side effects become bottlenecks in endometriosis. Thus, endometriosis warrants deeper exploration and expanded investigation in pathogenesis. The gut microbiota plays a significant role in chronic diseases in humans by acting as an important participant and regulator in the metabolism and immunity of the body. Increasingly, studies have shown that the gut microbiota is closely related to inflammation, estrogen metabolism, and immunity resulting in the development and progression of endometriosis. In this review, we discuss the diverse mechanisms of endometriosis closely related to the gut microbiota in order to provide new approaches for deeper exploration and expanded investigation for endometriosis on prevention, early diagnosis and treatment.

Targeting the Endocannabinoid System Present in the Glioblastoma Tumour Microenvironment as a Potential Anti-Cancer Strategy

The highly aggressive and invasive glioblastoma (GBM) tumour is the most malignant lesion among adult-type diffuse gliomas, representing the most common primary brain tumour in the neuro-oncology practice of adults. With a poor overall prognosis and strong resistance to treatment, this nervous system tumour requires new innovative treatment. GBM is a polymorphic tumour consisting of an array of stromal cells and various malignant cells contributing to tumour initiation, progression, and treatment response. Cannabinoids possess anti-cancer potencies against glioma cell lines and in animal models. To improve existing treatment, cannabinoids as functionalised ligands on nanocarriers were investigated as potential anti-cancer agents. The GBM tumour microenvironment is a multifaceted system consisting of resident or recruited immune cells, extracellular matrix components, tissue-resident cells, and soluble factors. The immune microenvironment accounts for a substantial volume of GBM tumours. The barriers to the treatment of glioblastoma with cannabinoids, such as crossing the blood-brain barrier and psychoactive and off-target side effects, can be alleviated with the use of nanocarrier drug delivery systems and functionalised ligands for improved specificity and targeting of pharmacological receptors and anti-cancer signalling pathways. This review has shown the presence of endocannabinoid receptors in the tumour microenvironment, which can be used as a potential unique target for specific drug delivery. Existing cannabinoid agents, studied previously, show anti-cancer potencies via signalling pathways associated with the hallmarks of cancer. The results of the review can be used to provide guidance in the design of future drug therapy for glioblastoma tumours.

Hodgkin Lymphoma: A disease shaped by the tumor micro- and macroenvironment

The tumor microenvironment (TMicroE) and tumor macroenvironment (TMacroE) are defining features of classical Hodgkin lymphoma (cHL). They are of critical importance to clinicians since they explain the common signs and symptoms, allow us to classify these neoplasms, develop prognostic and predictive biomarkers, bioimaging and novel treatments. The TMicroE is defined by effects of cancer cells to their immediate surrounding and within the tumor. Effects of cancer cells at a distance or outside of the tumor define the TMacroE. Paraneoplastic syndromes are signs and symptoms due to effects of cancer at a distance or the TMacroE, which are not due to direct cancer cell infiltration. The most common paraneoplastic symptoms are B-symptoms, which manifest as fevers, chills, drenching night sweats, and/or weight loss. Less common paraneoplastic syndromes include those that affect the central nervous system, skin, kidney, and hematological autoimmune phenomena including hemophagocytic lymphohistiocytosis (HLH). Paraneoplastic signs such as leukocytosis, lymphopenia, anemia, and hypoalbuminemia are prognostic biomarkers. The neoplastic cells in cHL are the Hodgkin and Reed Sternberg (HRS) cells, which are preapoptotic germinal center B cells with a high mutational burden and almost universal genetic alterations at the 9p24.1 locus primarily through copy gain and amplification with strong activation of signaling via PD-L1, JAK-STAT, NFkB, and c-MYC. In the majority of cases of cHL over 95% of the tumor cells are non-neoplastic. In the TMicroE, HRS cells recruit and mold non-neoplastic cells vigorously via extracellular vesicles, chemokines, cytokines and growth factors such as CCL5, CCL17, IL6, and TGF-β to promote a feed-forward inflammatory loop, which drives cancer aggressiveness and anti-cancer immune evasion. Novel single cell profiling techniques provide critical information on the role in cHL of monocytes-macrophages, neutrophils, T helper, Tregs, cytotoxic CD8+ T cells, eosinophils, mast cells and fibroblasts. Here, we summarize the effects of EBV on the TMicroE and TMacroE. In addition, how the metabolism of the TMicroE of cHL affects bioimaging and contributes to cancer aggressiveness is reviewed. Finally, we discuss how the TMicroE is being leveraged for risk adapted treatment strategies based on bioimaging results and novel immune therapies. In sum, it is clear that we cannot effectively manage patients with cHL without understanding the TMicroE and TMacroE and its clinical importance is expected to continue to grow rapidly.

Exploring tumor-normal cross-talk with TranNet: Role of the environment in tumor progression

There is a growing awareness that tumor-adjacent normal tissues used as control samples in cancer studies do not represent fully healthy tissues. Instead, they are intermediates between healthy tissues and tumors. The factors that contribute to the deviation of such control samples from healthy state include exposure to the tumor-promoting factors, tumor-related immune response, and other aspects of tumor microenvironment. Characterizing the relation between gene expression of tumor-adjacent control samples and tumors is fundamental for understanding roles of microenvironment in tumor initiation and progression, as well as for identification of diagnostic and prognostic biomarkers for cancers. To address the demand, we developed and validated TranNet, a computational approach that utilizes gene expression in matched control and tumor samples to study the relation between their gene expression profiles. TranNet infers a sparse weighted bipartite graph from gene expression profiles of matched control samples to tumors. The results allow us to identify predictors (potential regulators) of this transition. To our knowledge, TranNet is the first computational method to infer such dependencies. We applied TranNet to the data of several cancer types and their matched control samples from The Cancer Genome Atlas (TCGA). Many predictors identified by TranNet are genes associated with regulation by the tumor microenvironment as they are enriched in G-protein coupled receptor signaling, cell-to-cell communication, immune processes, and cell adhesion. Correspondingly, targets of inferred predictors are enriched in pathways related to tissue remodelling (including the epithelial-mesenchymal Transition (EMT)), immune response, and cell proliferation. This implies that the predictors are markers and potential stromal facilitators of tumor progression. Our results provide new insights into the relationships between tumor adjacent control sample, tumor and the tumor environment. Moreover, the set of predictors identified by TranNet will provide a valuable resource for future investigations.

Exploring tumor-normal cross-talk with TranNet: role of the environment in tumor progression

There is a growing awareness that tumor-adjacent normal tissues used as control samples in cancer studies do not represent fully healthy tissues. Instead, they are intermediates between healthy tissues and tumors. The factors that contribute to the deviation of such control samples from healthy state include exposure to the tumor-promoting factors, tumor-related immune response, and other aspects of tumor microenvironment. Characterizing the relation between gene expression of tumor-adjacent control samples and tumors is fundamental for understanding roles of microenvironment in tumor initiation and progression, as well as for identification of diagnostic and prognostic biomarkers for cancers. To address the demand, we developed and validated TranNet, a computational approach that utilizes gene expression in matched control and tumor samples to study the relation between their gene expression profiles. TranNet infers a sparse weighted bipartite graph from gene expression profiles of matched control samples to tumors. The results allow us to identify predictors (potential regulators) of this transition. To our knowledge, TranNet is the first computational method to infer such regulation. We applied TranNet to the data of several cancer types and their matched control samples from The Cancer Genome Atlas (TCGA). Many predictors identified by TranNet are genes associated with regulation by the tumor microenvironment as they are enriched in G-protein coupled receptor signaling, cell-to-cell communication, immune processes, and cell adhesion. Correspondingly, targets of inferred predictors are enriched in pathways related to tissue remodelling (including the epithelial-mesenchymal Transition (EMT)), immune response, and cell proliferation. This implies that the predictors are markers and potential stromal facilitators of tumor progression. Our results provide new insights for the relationships between tumor adjacent control sample, tumor and the tumor environment. Moreover, the set of predictors identified by TranNet will provide a valuable resource for future investigations. The TranNet method was implemented in python, source codes and the data sets used for and generated during this study are available at the Github site https://github.com/ncbi/TranNet .

Systematic Characterization of the Disruption of Intestine during Liver Tumor Progression in the xmrk Oncogene Transgenic Zebrafish Model

The crosstalk between tumors and their local microenvironment has been well studied, whereas the effect of tumors on distant tissues remains understudied. Studying how tumors affect other tissues is important for understanding the systemic effect of tumors and for improving the overall health of cancer patients. In this study, we focused on the changes in the intestine during liver tumor progression, using a previously established liver tumor model through inducible expression of the oncogene xmrk in zebrafish. Progressive disruption of intestinal structure was found in the tumor fish, displaying villus damage, thinning of bowel wall, increase in goblet cell number, decrease in goblet cell size and infiltration of eosinophils, most of which were observed phenotypes of an inflammatory intestine. Intestinal epithelial cell renewal was also disrupted, with decreased cell proliferation and increased cell death. Analysis of intestinal gene expression through RNA-seq suggested deregulation of genes related to intestinal function, epithelial barrier and homeostasis and activation of pathways in inflammation, epithelial mesenchymal transition, extracellular matrix organization, as well as hemostasis. Gene set enrichment analysis showed common gene signatures between the intestine of liver tumor fish and human inflammatory bowel disease, the association of which with cancer has been recently noticed. Overall, this study represented the first systematic characterization of the disruption of intestine under the liver tumor condition and suggested targeting intestinal inflammation as a potential approach for managing cancer cachexia.

New Developments and Opportunities of Microbiota in Treating Breast Cancers

Despite the prevalence of breast cancer (BC), over half of BC cases are unrelated to known risk factors, which highlights the importance of uncovering more cancer-related factors. Currently, the microbiota has been proven to be a potent modulator of the tumor environment in BC, which regulates the immune balance in tumor-related networks. Through a large amount of data accumulation, the microbiota has shown many possibilities to reveal more insights into the development or control of BC. To expand the potential benefits of patients with BC, this study discusses the distribution profile and the effect mechanism of BC-related microbiota on tumors and further discusses its impact on different tumor therapies. Finally, we summarize the possibility of targeting microbiological therapies to improve BC treatment or in combination with other therapies.

An Update to Hallmarks of Cancer

In the last decade, there has been remarkable progress in research toward understanding and refining the hallmarks of cancer. In this review, we propose a new hallmark - "pro-survival autophagy." The importance of pro-survival autophagy is well established in tumorigenesis, as it is related to multiple steps in cancer progression and vital for some cancers. Autophagy is a potential anti-cancer therapeutic target. For this reason, autophagy is a good candidate as a new hallmark of cancer. We describe two enabling characteristics that play a major role in enabling cells to acquire the hallmarks of cancer - "tumor-promoting microenvironment and macroenvironment" and "cancer epigenetics, genome instability and mutation." We also discuss the recent updates, therapeutic and prognostic implications of the eight hallmarks of cancer described by Hanahan et al. in 2011. Understanding these hallmarks and enabling characteristics is key not only to developing new ways to treat cancer efficiently but also to exploring options to overcome cancer resistance to treatment.

TUMOR CELL MALIGNANCY: A COMPLEX TRAIT BUILT THROUGH RECIPROCAL INTERACTIONS BETWEEN TUMORS AND TISSUE-BODY SYSTEM

Since the discovery of oncogenes and tumor suppressor genes in the late past century, cancer research has been overwhelmingly focused on the genetics and biology of tumor cells and hence has addressed mostly cell-autonomous processes with emphasis on traditional driver/passenger genetic models. Nevertheless, over that same period, multiple seminal observations have accumulated highlighting the role of non-cell autonomous effectors in tumor growth and metastasis. However, given that cell autonomous and non-autonomous events are observed together at the time of diagnosis, it is in fact impossible to know whether the malignant transformation is initiated by cell autonomous oncogenic events or by non-cell autonomous conditions generated by alterations of the tissue-body ecosystem. This review aims at addressing this issue by taking the option of defining malignancy as a complex genetic trait incorporating genetically determined reciprocal interactions between tumor cells and tissue-body ecosystem.

Hyperactive neutrophils infiltrate vital organs of tumor bearing host and contribute to gradual systemic deterioration via upregulated NE, MPO and MMP-9 activity

Cancer is known to have systemic impact by targeting various organs that ultimately compromises the overall physiology of the host. Several reports have demonstrated the role of neutrophils in cancer wherein the focus has been drawn on the elevated neutrophil count in blood or at tumor loci. However, their role in mediating systemic effects during cancer progression has not been deciphered so far. Therefore, it is worthwhile to explore whether and how neutrophils contribute to systemic deterioration in cancer. To discern their systemic role, we evaluated neutrophil count and function at different stages of tumor growth in Dalton's Lymphoma mice model. Notably, our results displayed a gradual increase in Ly6G⁺ neutrophils in peripheral blood and their infiltration in vital organs including liver, lungs, spleen, kidney, lymph nodes and peritoneum of tumor bearing host. We showed remarkable alterations in histoarchitecture and serum enzyme levels that aggravated with tumor progression. We next examined neutrophil function by assessing its granular cargoes including neutrophil elastase (NE), myeloperoxidase (MPO), and matrix metalloproteinases (MMP-8 and MMP-9). Interestingly, blood neutrophils of tumor bearing mice exhibited a marked change in morphology with gradual increase in NE and MPO expression with tumor growth. In addition, we observed upregulated expression of NE, MPO, MMP-8 and MMP-9 in the vital organs of tumor bearing host. Taken together, our results demonstrate heightened infiltration and function of neutrophils in vital organs of tumor bearing host which possibly account for gradual systemic deterioration during cancer progression. Our findings thus implicate neutrophils as a potential therapeutic target that may help to reduce the overall fatality rate of cancer.

Gut Microbiota: A Potential Target for Cancer Interventions

The gut microbiota plays a crucial role in many physiological processes in the human body. Dysbiosis can disrupt the intestinal barrier and alter metabolism and immune responses, leading to the development of diseases. Over the past few decades, evidence has accumulated linking changes in the composition of the gut microbiota to dozens of seemingly unrelated conditions, including cancer. Overall, the gut microbiota mainly affects the occurrence and development of cancer by damaging host DNA, forming and maintaining a pro-inflammatory environment, and affecting host immune responses. In addition, the gut microbiota can also affect the efficacy and toxicity of chemotherapy, radiotherapy, and immunotherapy. Scientists attempt to improve the efficacy and decrease the toxicity of these treatment modalities by fine-tuning the gut microbiota. The aim of this review is to assist researchers and clinicians in developing new strategies for the detection and treatment of tumors by providing the latest information on the intestinal microbiome and cancer, as well as exploring potential application prospects and mechanisms of action.

Texture Analysis of Tumor and Peritumoral Tissues Based on 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Hybrid Imaging in Patients With Rectal Cancer

OBJECTIVE

This study aimed to determine whether texture parameters could be used in differentiation between the tumor and the peritumoral tissues based on hybrid 18F-Fluorodeoxyglucose positron emission tomography/computed tomography imaging for patients with rectal cancer.

METHODS

Seven parameters, including heterogeneity, entropy, energy, skewness, kurtosis, standard deviation, and average brightness, were extracted from positron emission tomography/computed tomography scans of 22 patients (12 male and 10 female; mean age, 61 ± 2 years).

RESULTS

The peritumoral tissue had a significantly lower value of the heterogeneity parameter (23%) than the tumor. Tumor size (r = -0.48, P < 0.05) and extramural venous invasion scores (r = 0.64, P < 0.05) correlated with heterogeneity in the peritumoral tissue. There were significant differences (P < 0.05) in the correlation coefficients between men and women.

CONCLUSIONS

Therefore, we provided additional quantitative information to differentiate the tumor from the peritumoral tissue and indicated possible application for extramural venous invasion evaluation in rectal cancer.

Noise and the molecular processes underlying cell fate decision-making

Cell fate decision-making events involve the interplay of many molecular processes, ranging from signal transduction to genetic regulation, as well as a set of molecular and physiological feedback loops. Each aspect offers a rich field of investigation in its own right, but to understand the whole process, even in simple terms, we need to consider them together. Here we attempt to characterise this process by focussing on the roles of noise during cell fate decisions. We use a range of recent results to develop a view of the sequence of events by which a cell progresses from a pluripotent or multipotent to a differentiated state: chromatin organisation, transcription factor stoichiometry, and cellular signalling all change during this progression, and all shape cellular variability, which becomes maximal at the transition state.

Cancer Stem Cells in the Immune Microenvironment

Cancer stem cells are a subpopulation of cancer cells responsible for the most demanding and aggressive cancer cell phenotypes: therapy resistance, a self-protective feature of stem cells; distant metastasis, requiring anchorage independence for survival in the circulation; and recurrence, which is related to the dormant-active cycling of stem cells. Normal tissues are composed of parenchymal cells, supportive connective components, and cellular disposal systems for removing the products of physiological wear and tear. Cancer stem cells develop from normal counterparts and progressively interact with their microenvironments, modifying and conditioning the cancer microenvironment. Cancer-associated myeloid cells constitute a major element of the cancer microenvironment. During the process of carcinogenesis, cancer stem cells and their intimately associated myeloid cells mutually interact and evolve, such that the cancer cells potentiate the activity of the myeloid cells and, in return, the myeloid cells increase cancer stem cell characteristics. Normal myeloid cells function as key accessory cells to maintain homeostasis in normal tissues and organs; in cancers, these cells co-evolve with the malignant parenchymal cells and are involved in every aspect of cancer cell biology, including proliferation, invasion, distant metastasis, and the development of resistance to therapy. In this way, cancer-associated myeloid cells provide two of the key hallmarks of cancer: evasion of immune destruction and cancer-promoting inflammation.

Breast and Gut Microbiota Action Mechanisms in Breast Cancer Pathogenesis and Treatment

In breast cancer (BC) the employment of sequencing technologies for metagenomic analyses has allowed not only the description of the overall metagenomic landscape but also the specific microbial changes and their functional implications. Most of the available data suggest that BC is related to bacterial dysbiosis in both the gut microenvironment and breast tissue. It is hypothesized that changes in the composition and functions of several breast and gut bacterial taxa may contribute to BC development and progression through several pathways. One of the most prominent roles of gut microbiota is the regulation of steroid-hormone metabolism, such as estrogens, a component playing an important role as risk factor in BC development, especially in postmenopausal women. On the other hand, breast and gut resident microbiota are the link in the reciprocal interactions between cancer cells and their local environment, since microbiota are capable of modulating mucosal and systemic immune responses. Several in vivo and in vitro studies show remarkable evidence that diet, probiotics and prebiotics could exert important anticarcinogenic effects in BC. Moreover, gut microbiota have an important role in the metabolism of chemotherapeutic drugs and in the activity of immunogenic chemotherapies since they are a potential dominant mediator in the response to cancer therapy. Then, the microbiome impact in BC is multi-factorial, and the gut and breast tissue bacteria population could be important in regulating the local immune system, in tumor formation and progression and in therapy response and/or resistance.

Liver prometastatic reaction: Stimulating factors and responsive cancer phenotypes

Cancer is first a localized tissue disorder, whose soluble and exosomal molecules and invasive cells induce a host response providing the stromal components of the primary tumor microenvironment (TME). Once the TME is developed, cancer-derived molecules and cells can more efficiently spread out and a whole-body response takes place, whose pathophysiological changes may result in a paraneoplastic syndrome. Remote organ-specific prometastatic reactions may also occur at this time, facilitating metastatic activities of circulating tumor cells (CTCs) through premetastatic niche development at targeted organs. However, additional signaling factors from the inter-organ communication network involved in the pathophysiology and comorbidities of cancer patients may also regulate prometastatic reaction-stimulating effects of cancer and non-cancer tissue factors. This article provides a conceptual overview of our ongoing clinical research on the liver prometastatic reaction (LPR) of patients with colorectal cancer (CRC), their portal vein- and hepatic artery-driven LPR-Stimulating Factors (LPR-SF), and their resulting LPR-derived Metastasis-Stimulating Factors (LPR-MSF) acting on liver-invading CRC cells. In addition, we also provide new insights on the molecular subtyping of LPR-responsive cancer phenotypes in patients with CRC and melanoma; and on how to investigate and interpret the prometastatic infrastructure in the real pathophysiological context of patients with cancer undergoing surgical procedures and receiving pharmacological treatments with multiple side effects, including those affecting the LPR, its stimulating factors and responsive cancer phenotypes.

The Neuroimmune Axis in the Tumor Microenvironment

Cancer is a complex ecosystem and should be considered in the context of its cellular and molecular microenvironment, which includes the nerves. Peripheral nerves can modulate phenotype and behavior of the malignant cells and thus affect tumor growth and metastasis. Only recently has the role of neuroimmune cross-talk surfaced as a key contributor to cancer progression. However, little is known about the immunomodulatory role of the neuroglial cells in cancer progression and metastasis and the response to therapy. Schwann cells, the principal glial cells of the peripheral nervous system, are now considered to be important players in the tumor microenvironment. They can directly accelerate malignant cell migration and the formation of metastases. Better understanding of the neuroimmune circuits in the tumor milieu will be instrumental in the development of novel therapeutic approaches for the malignancies known to be associated with inflammation and dysregulated immune responses.

The Effects of Preoperative Oral Carbohydrate on Frequency of T and NK Cells in Patients with Cervical Cancer Treated Using Neoadjuvant Chemotherapy and Surgery: A Prospective Cohort Study

Background

Immune dysfunction can occur after neoadjuvant chemotherapy (NAC) and surgery for cancer. We investigated whether preoperative oral carbohydrate affected the postoperative percentages of T cells (CD4⁺ and CD8⁺) and natural killer (NK) cells in patients with cervical cancer treated with NAC and surgery.

Methods

This prospective cohort study enrolled consecutive patients with cervical cancer treated by radical hysterectomy with PLND at the Gynecologic Oncology Department of Fujian Provincial Cancer Hospital (China) between January 2018 and December 2018. Patients were divided into three groups according to the treatment method: NAC (two cycles, surgery 1 month later), NAC+CHO (chemotherapy and surgical methods same as with the NAC group but with 300 mL of oral carbohydrate administered 2 h before surgery), and non-NAC (surgery alone). Percentages of NK, CD3⁺, CD4⁺, and CD8⁺ cells were evaluated by flow cytometry the day after the first admission, just before surgery, immediately after tracheal tube removal, and the day after surgery. This trial is registered with NCT03872635 at clinicaltrials.com.

Results

The final analysis included 77 patients (non-NAC group, n = 26; NAC group, n = 25; and NAC-CHO group, n = 26). Baseline characteristics and preoperative NK, CD3⁺, CD4⁺, and CD8⁺ cell percentages were similar between groups. Postoperatively, all groups exhibited reductions in NK, CD3⁺, and CD4⁺ cell percentages and increases in CD8⁺ cell percentages (all P < 0.05). The changes in NK, CD3⁺, CD4⁺, and CD8⁺ cell percentages were attenuated in the NAC-CHO group (P < 0.05 vs. both other groups).

Conclusion

Preoperative oral carbohydrate can improve the postoperative populations of NK and T cells after the treatment of cervical cancer by NAC and surgery.

Microsomal prostaglandin E synthase-1 promotes lung metastasis via SDF-1/CXCR4-mediated recruitment of CD11b+Gr1+MDSCs from bone marrow

BACKGROUND

Accumulation of myeloid-derived suppressor cells (MDSCs) to tumors is related to cancer prognosis. We investigated the contribution of host stromal microsomal prostaglandin E synthase-1 (mPGES-1) to the accumulation of MDSCs in metastasized lungs of prostate cancer in mice.

MATERIAL AND METHODS

Eight-week-old male C57Bl/6 wild type (WT) mice and mPGES-1 knock out mice (mPGES-1KO) were injected with RM9 murine prostate cancer cell line (5 × 10⁶ cells/mL). Lung metastasis was evaluated by the number of colonies, the weight of the lung, and the number of MDSCs (CD11b⁺Gr1⁺ cells) in the lung.

RESULTS

Intravenous injections of RM9, a murine prostate cancer cell line to WT mice revealed that lung metastasis and accumulation of MDCSs were suppressed with treatments with a Gr1 antibody, a COX-2 inhibitor, and an mPGES-1 inhibitor. Lung metastasis and accumulation of CD11b⁺Gr1⁺MDSCs were suppressed in mPGES-1KO mice. The mRNA level of stromal cell-derived factor-1 (SDF-1) in the lung and the number of accumulated SDF-1-expressing CD11b⁺Gr1⁺ MDSCs were elevated at an early stage in lung metastasis of C-X-C chemokine receptor type 4 (CXCR4)-expressing RM9 in an mPGES-1-dependent manner. The number of CXCR4-expressing CD11b⁺Gr1⁺MDSCs in WT mice was higher than that in mPGES-1KO mice. RM9 lung metastasis and accumulation of CD11b⁺Gr1⁺MDSCs were suppressed by CXCR4 antibody in WT mice but not in mPGES-1KO. WT mice transplanted with mPGES-1 KO bone marrow (BM) showed a significant reduction in lung metastasis and accumulation of CD11b⁺Gr1⁺MDSCs.

CONCLUSION

These results suggest that mPGES-1 enhances tumor metastasis by inducing accumulation of BM-derived MDSCs. Selective mPGES-1 inhibitors might, therefore, represent valuable therapeutic tools for the suppression of tumor metastasis.

Circadian Clocks and Cancer: Timekeeping Governs Cellular Metabolism

The circadian clock is a biological mechanism that dictates an array of rhythmic physiological processes. Virtually all cells contain a functional clock whose disruption results in altered timekeeping and detrimental systemic effects, including cancer. Recent advances have connected genetic disruption of the clock with multiple transcriptional and signaling networks controlling tumor initiation and progression. An additional feature of this circadian control relies on cellular metabolism, both within the tumor microenvironment and the organism systemically. A discussion of major advances related to cancer metabolism and the circadian clock will be outlined, including new efforts related to metabolic flux of transformed cells, metabolic heterogeneity of tumors, and the implications of circadian control of these pathways.

Differential expression profiles of the transcriptome in bone marrow-derived cells in lung cancer revealed by next generation sequencing and bioinformatics

A pre-metastatic niche (PMN) facilitates cancer metastasis through mobilization and recruitment of bone marrow-derived cells (BMDCs) and associated factors. In bone marrow, hematogenous cells, including osteoclasts, macrophages and lymphocytes, and mesenchymal cells, including mesenchymal stem cells, osteoblasts and adipocytes, are involved in PMN formation. Patients with lung cancer and metastasis have a poor prognosis and shortened median survival time. Bone marrow has been considered fertile ground for dormant and proliferating tumor cells, and mobilizing and recruiting BMDCs and immune cells can establish a PMN. However, the role of BMDCs in PMN formation is not yet fully understood. The present study aimed to investigate the association between BMDCs and PMN in bone marrow tissue samples. The results demonstrated that bone marrow served an important role in lung cancer progression and that eight pathways were potentially involved, including ‘T-cell receptor signaling pathway’, ‘osteoclast differentiation’, ‘MAPK signaling pathway’, ‘VEGF signaling pathway’, ‘leukocyte transendothelial migration’, ‘signaling pathways regulating the pluripotency of stem cells’, ‘oxytocin signaling pathway’ and ‘cell adhesion molecules (CAMs)’. In addition, the present study investigated the role of BMDCs in facilitating lung cancer metastasis. In conclusion, the results from the present study suggested that molecular alterations in gene expression may provide a novel signature in lung cancer, which may aid in the development of novel diagnostic and therapeutic strategies for patients with lung cancer and bone metastasis.

The emerging link between cancer, metabolism, and circadian rhythms

The circadian clock is a complex cellular mechanism that, through the control of diverse metabolic and gene expression pathways, governs a large array of cyclic physiological processes. Epidemiological and clinical data reveal a connection between the disruption of circadian rhythms and cancer that is supported by recent preclinical data. In addition, results from animal models and molecular studies underscore emerging links between cancer metabolism and the circadian clock. This has implications for therapeutic approaches, and we discuss the possible design of chronopharmacological strategies.

Solid peripheral tumor leads to systemic inflammation, astrocyte activation and signs of behavioral despair in mice

Prevalence of depression is higher in patients with cancer than in the general population. Sustained systemic inflammation has been associated with depressive behavior and it has been reported that depressed patients commonly display alterations in their immune system. We previously showed that cancer in mice induces a systemic environment that promotes neutrophil activation and leukocytosis. We thus hypothesized that the peripheral systemic response to a solid tumor leads to endothelial activation, which may promote inflammatory changes in the brain with behavioral consequences. Using the Lewis lung carcinoma (LLC) model, we show that tumor growth induces a progressive increase in peripheral inflammation as observed by elevated interleukin-6 (IL-6). In behavioral studies, tumor-bearing mice showed no sign of motor, coordination or short term working memory deficits as assessed by rotarod, balance-beam, and novel object recognition tests. However, there was an impairment in the grip strength test and interestingly, an anxious and despair-like phenotype in the elevated plus-maze, and tail suspension tests, respectively. Immunostaining of perfused brains revealed fibrin accumulation in the vasculature with some leakage into the parenchyma, a process known to activate endothelial cells. Taken together, our results suggest that the inflamed and prothrombotic systemic environment created by the growth of a peripherally-located solid tumor induces endothelial activation, accumulation of fibrin in the brain and astrocyte activation, perhaps leading to depressive-like behavior.

Tumor-derived exosomes, microRNAs, and cancer immune suppression

Originally considered to be part of a cellular waste pathway, expansive research into exosomes has shown that these vesicles possess a vast array of functional utilities. As vital transporters of materials for communications between cells, particular interest has been generated in the ability of cancer cells to use exosomes to induce immune suppression, and to establish a thriving microenvironment, ideal for disease progression. Exosomes carry and transfer many types of cargo, including microRNAs (miRNAs; miRs), which are important modulators of messenger RNA (mRNA) expression. These miRNAs have been shown to be noteworthy components of the mechanisms used by tumor-derived exosomes to carry out their functions. Alternatively, research has been expanding into using exosomes and miRNAs as both biomarkers for detecting cancer and disease progression, and as potential treatment tools. Here, we discuss some of the progress that researchers have made related to cancer exosomes, their suppression of the immune system and the importance of the miRNAs they shuttle, along with some of the shortcomings, obstacles, and challenges that lie ahead.

A new role for extracellular vesicles: how small vesicles can feed tumors' big appetite

Cancer cells must adapt their metabolism in order to meet the energy requirements for cell proliferation, survival in nutrient-deprived environments, and dissemination. In particular, FA metabolism is emerging as a critical process for tumors. FA metabolism can be modulated through intrinsic changes in gene expression or signaling between tumor cells and also in response to signals from the surrounding microenvironment. Among these signals, extracellular vesicles (EVs) could play an important role in FA metabolism remodeling. In this review, we will present the role of EVs in tumor progression and especially in metabolic reprogramming. Particular attention will be granted to adipocytes. These cells, which are specialized in storing and releasing FAs, are able to shift tumor metabolism toward the use of FAs and, subsequently, increase tumor aggressiveness. Recent work demonstrates the involvement of EVs in this metabolic symbiosis.

The role of mmu-miR-155-5p-NF-κB signaling in the education of bone marrow-derived mesenchymal stem cells by gastric cancer cells

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are important precursors of tumor stromal cells. Previously, we have demonstrated that miR-155-5p inhibition directly induced transition of BM-MSCs into gastric cancer-associated MSCs. Whether miR-155-5p is involved in the education of BM-MSCs by gastric cancer cells has not been established. Murine BM-MSCs (mMSCs) were isolated and grown in conditioned medium derived from gastric cancer cell line MFC (MFC-CM). The tumor-promoting phenotype and function of mMSCs were detected by immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), cell colony formation assay, transwell migration, and invasion assays. Luciferase reporter assays and western blot analyses were conducted to reveal the relationship between nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 and mmu-miR-155-5p. miRNA mimics, inhibitor, and the NF-κB inhibitor pyrrolidine dithiocarbamic acid (PDTC) were used to evaluate the role of miR-155-5p-NF-κB signaling in the education of mMSCs by MFC-CM. We successfully established the education model of mMSCs by MFC-CM and found that mmu-miR-155-5p expression levels were reduced in mMSCs. Mimicking this deregulation by transfecting miRNA inhibitor into mMSCs produced a similar effect as that of MFC-CM on mMSCs. NF-κB p65 was validated as a target of mmu-miR-155-5p, which also negatively regulated NF-κB activation. Inhibition of NF-κB activation by PDTC abolished the effect of the miRNA inhibitor on mMSCs. mmu-miR-155-5p overexpression partially blocked the effect of MFC-CM in educating mMSCs, while PDTC treatment completely eliminated MFC-CM activity. These results indicate that miR-155-5p is not the sole miRNA mediating the education of BM-MSCs by gastric cancer cells, but downstream NF-κB signaling is indispensable for this process.

T- and NK-cell populations with regulatory phenotype and markers of apoptosis in circulating lymphocytes of patients with CIN3 or microcarcinoma of the cervix: evidence for potential mechanisms of immune suppression

BACKGROUND

Processes and mechanisms responsible for systemic immune suppression in early-stage cervical cancer remain substantially underinvestigated. In this work, we focused on studying the frequencies of circulating regulatory T (CD4 and CD8 Tregs) and NK (NKregs) cells in parallel with assessment of apoptotic markers expression in T cells from patients with preinvasive and microinvasive cervical cancer, with the aim to determine whether up-regulation of apoptosis-associated markers in Т lymphocytes accompanies cervical cancer development and correlates with the change in percentages of regulatory cell populations at systemic level during the initial stages of invasive cervical cancer progression.

METHODS

Fourty two women with histologically confirmed cervical intraepithelial neoplasia grade 3 (CIN3, including carcinoma in situ) or cervical cancer (stage IA) and 30 healthy women (control) were enrolled in the study. Peripheral blood samples were taken immediately before surgery or any treatment and immediately subjected to multicolor flow cytometry.

RESULTS

Analysis of a combination of CD4/CD8, CD25, CD127, and FoxP3 markers revealed a statistically significant increase in the frequencies of Tregs within both the CD4 and CD8 subsets of circulating lymphocytes in patients with CIN3 and stage IA cancer. In contrast, lower numbers of NKregs (defined as CD16^dim/negCD56^bright subpopulation) and increased CD56^dim/CD56^bright NK ratio were found in patients compared to controls, with the percentage of CD16^brightCD56^dim cells (major subtype of circulating NKs) showing no difference. Patients also exhibited an increased expression of CD95 in total peripheral blood T lymphocytes, along with increased level of Annexin V binding to CD95-positive cells, suggesting higher susceptibility of T cells to apoptosis and potential involvement of CD95-dependent pathway in early-stage cervical cancer. Differential analysis of CD4 and CD8 T cells revealed different trends in the change of CD95 expression, confirming that this change likely has different functional significance for these two subsets. A search for correlations between the phenotypic parameters analyzed in this study was performed to demonstrate that women with early neoplastic lesions of the cervix, such as carcinoma in situ and microinvasive carcinoma, displayed a coordinated increase in expression of Treg markers in circulating lymphocytes, along with more pronounced cross-relationships between Treg numbers, CD95 expression on T cells, and apoptosis, compared to the control group.

CONCLUSIONS

The results of this study suggest that a diversity of immune regulatory mechanisms that provide support for initial stages of invasive growth in cervical cancer patients includes systemic changes in the ratios between the principal regulatory and effector lymphocyte populations both within adaptive and innate immunity.

Changes in the gastrointestinal microbiota of children with acute lymphoblastic leukaemia and its association with antibiotics in the short term

Purpose. To detect the alteration of gut bacteria in children with ALL and analyse the impact of short-term-use of antibiotics on the changes caused by ALL.Methodology. We collected faecal samples from both children with ALL and healthy children. According to their medication history with antibiotics, we classified the samples into ALL+ATBx, ALL, CON+ATBx and CON groups. Next-generation sequencing was performed to identify the gut bacteria according to the MiSeq platform. The Shannon index, Simpson index, Chao index and Ace index were used to represent the alpha diversity of gut bacteria. The beta diversity was estimated using the principles of co-ordinate analysis and non-metric multi-dimensional scaling. The taxon composition and presence of biomarkers were then determined through bioinformatics.Results. With regard to alpha diversity, the Shannon index and Simpson index differed significantly between the ALL and CON groups, as well as the CON+ATBx and CON groups, but not the ALL+ATBx and CON+ATBx groups. With regard to beta diversity, the ALL and CON separated clearly into clusters, as did ALL+ATBx and CON+ATBx. There were differences in composition among the four groups at different taxonomy hierarchies. More bacteria showed an obvious difference between the paired groups ALL and CON than did for the paired groups ALL+ATBx and CON+ATBx. The area under the receiver operating characteristic curves for Bacteroidales and Enterococcaceae used to predict ALL were 0.735 and 0.724, respectively.Conclusion. ALL induced structural changes of the gut microbiota, with the alpha diversity being significantly weakened by antibiotics, but not beta diversity. Bacteroidales and Enterococcaceae can be referred to as biomarkers for ALL.

Trametinib Drives T-cell-Dependent Control of KRAS-Mutated Tumors by Inhibiting Pathological Myelopoiesis

Targeted therapies elicit seemingly paradoxical and poorly understood effects on tumor immunity. Here, we show that the MEK inhibitor trametinib abrogates cytokine-driven expansion of monocytic myeloid-derived suppressor cells (mMDSC) from human or mouse myeloid progenitors. MEK inhibition also reduced the production of the mMDSC chemotactic factor osteopontin by tumor cells. Together, these effects reduced mMDSC accumulation in tumor-bearing hosts, limiting the outgrowth of KRas-driven breast tumors, even though trametinib largely failed to directly inhibit tumor cell proliferation. Accordingly, trametinib impeded tumor progression in vivo through a mechanism requiring CD8⁺ T cells, which was paradoxical given the drug's reported ability to inhibit effector lymphocytes. Confirming our observations, adoptive transfer of tumor-derived mMDSC reversed the ability of trametinib to control tumor growth. Overall, our work showed how the effects of trametinib on immune cells could partly explain its effectiveness, distinct from its activity on tumor cells themselves. More broadly, by providing a more incisive view into how MEK inhibitors may act against tumors, our findings expand their potential uses to generally block mMDSC expansion, which occurs widely in cancers to drive their growth and progression. Cancer Res; 76(21); 6253-65. ©2016 AACR.

Versican-Derived Matrikines Regulate Batf3-Dendritic Cell Differentiation and Promote T Cell Infiltration in Colorectal Cancer

Colorectal cancer originates within immunologically complex microenvironments. To date, the benefits of immunotherapy have been modest, except in neoantigen-laden mismatch repair-deficient tumors. Approaches to enhance tumor-infiltrating lymphocytes in the tumor bed may substantially augment clinical immunotherapy responses. In this article, we report that proteolysis of the tolerogenic matrix proteoglycan versican (VCAN) strongly correlated with CD8⁺ T cell infiltration in colorectal cancer, regardless of mismatch repair status. Tumors displaying active VCAN proteolysis and low total VCAN were associated with robust (10-fold) CD8⁺ T cell infiltration. Tumor-intrinsic WNT pathway activation was associated with CD8⁺ T cell exclusion and VCAN accumulation. In addition to regulating VCAN levels at the tumor site, VCAN proteolysis results in the generation of bioactive fragments with novel functions (VCAN-derived matrikines). Versikine, a VCAN-derived matrikine, enhanced the generation of CD103⁺CD11c^hiMHCII^hi conventional dendritic cells (cDCs) from Flt3L-mobilized primary bone marrow-derived progenitors, suggesting that VCAN proteolysis may promote differentiation of tumor-seeding DC precursors toward IRF8- and BATF3-expressing cDCs. Intratumoral BATF3-dependent DCs are critical determinants for T cell antitumor immunity, effector T cell trafficking to the tumor site, and response to immunotherapies. Our findings provide a rationale for testing VCAN proteolysis as a predictive and/or prognostic immune biomarker and VCAN-derived matrikines as novel immunotherapy agents.

Unravelling the complexity of signalling networks in cancer: A review of the increasing role for computational modelling

Cancer induction is a highly complex process involving hundreds of different inducers but whose eventual outcome is the same. Clearly, it is essential to understand how signalling pathways and networks generated by these inducers interact to regulate cell behaviour and create the cancer phenotype. While enormous strides have been made in identifying key networking profiles, the amount of data generated far exceeds our ability to understand how it all "fits together". The number of potential interactions is astronomically large and requires novel approaches and extreme computation methods to dissect them out. However, such methodologies have high intrinsic mathematical and conceptual content which is difficult to follow. This review explains how computation modelling is progressively finding solutions and also revealing unexpected and unpredictable nano-scale molecular behaviours extremely relevant to how signalling and networking are coherently integrated. It is divided into linked sections illustrated by numerous figures from the literature describing different approaches and offering visual portrayals of networking and major conceptual advances in the field. First, the problem of signalling complexity and data collection is illustrated for only a small selection of known oncogenes. Next, new concepts from biophysics, molecular behaviours, kinetics, organisation at the nano level and predictive models are presented. These areas include: visual representations of networking, Energy Landscapes and energy transfer/dissemination (entropy); diffusion, percolation; molecular crowding; protein allostery; quinary structure and fractal distributions; energy management, metabolism and re-examination of the Warburg effect. The importance of unravelling complex network interactions is then illustrated for some widely-used drugs in cancer therapy whose interactions are very extensive. Finally, use of computational modelling to develop micro- and nano- functional models ("bottom-up" research) is highlighted. The review concludes that computational modelling is an essential part of cancer research and is vital to understanding network formation and molecular behaviours that are associated with it. Its role is increasingly essential because it is unravelling the huge complexity of cancer induction otherwise unattainable by any other approach.

Reciprocal influence of B cells and tumor macro and microenvironments in the ApcMin/+ model of colorectal cancer

One of the most fascinating aspects of the immune system is its dynamism, meant as the ability to change and readapt according to the organism needs. Following an insult, we assist to the spontaneous organization of different immune cells which cooperate, locally and at distance, to build up an appropriate response. Throughout tumor progression, adaptations within the systemic tumor environment, or macroenvironment, result in the promotion of tumor growth, tumor invasion and metastasis to distal organs, but also to dramatic changes in the activity and composition of the immune system. In this work, we show the changes of the B-cell arm of the immune system following tumor progression in the Apc^Min/+ model of colorectal cancer. Tumor macroenvironment leads to an increased proportion of total and IL-10-competent B cells in draining LNs while activates a differentiation route that leads to the expansion of IgA⁺ lymphocytes in the spleen and peritoneum. Importantly, serum IgA levels were significantly higher in Apc^Min/+ than Wt mice. The peculiar involvement of IgA response in the adenomatous transformation had correlates in the gut-mucosal compartment where IgA-positive elements increased from normal mucosa to areas of low grade dysplasia while decreasing upon overt carcinomatous transformation. Altogether, our findings provide a snapshot of the tumor education of B lymphocytes in the Apc^Min/+ model of colorectal cancer. Understanding how tumor macroenvironment affects the differentiation, function and distribution of B lymphocytes is pivotal to the generation of specific therapies, targeted to switching B cells to an anti-, rather than pro-, tumoral phenotype.

Cancer is a propagandist

Communication among cells (also known as cross-talk) plays a prominent role in the current knowledge of the pathophysiology of cancer and of cancer-associated conditions such as paraneoplastic syndromes and cachexia that are responsible for much of cancer's morbidity and mortality. Yet, biomedical scientists lack an explicit unifying frame that places this exchange of molecular information at the core of their understanding of cancer as a systemic disease. Propaganda is a type of information that aims at misleading, a form of communication intended primarily to serve the messenger. The biased molecular cross-talk between cancer and non-cancer cells can be considered as a form of biological propaganda. I here propose cancer is a propagandist as a metaphor that may serve as a unifying frame to interpret both cancer and cancer-associated syndromes under the same communication-based concept and may thus serve to bring together research that is currently compartmentalized under separate disciplines.

"Pre-metastatic niches" in breast cancer: are they created by or prior to the tumour onset? "Flammer Syndrome" relevance to address the question

Breast cancer (BC) epidemic in the twenty-first century is characterised by around half a million deaths and 1.7 million new cases registered annually worldwide. Metastatic disease is the major cause of death in BC patient cohorts. Current statistics are much alarming from the viewpoint of the early mortality amongst BC patients with de novo metastatic disease. A new paradigm of so-called "pre-metastatic niches" may sufficiently promote our knowledge regarding potential pathomechanisms, individual predisposition and prognosis in development and progression of the metastatic disease. However, the crucial question remains unaddressed, whether hypoxic pre-metastatic niches in BC are created by or prior to the tumour onset. So far, the current interpretation of the "Seed and Soil" theory of metastasis proposing that the pre-metastatic niches are formed by primary tumours which "induce and guide" the process is incomplete, since it does not provide satisfactory explanations towards several facts overviewed in the article. The overall results of this study clearly support the working hypothesis presented by the authors proposing that the epi/genetic predisposition of individuals at risk to form the systemic hypoxic pre-metastatic niches can be established a long time before breast malignancy is clinically manifested. "Flammer Syndrome" (FS) phenotype may strongly contribute to particularly poor outcomes of metastatic breast cancer. Significance and relevance of individual FS symptoms for breast cancer metastatic disease are discussed in extenso.

The MLL1-H3K4me3 Axis-Mediated PD-L1 Expression and Pancreatic Cancer Immune Evasion

BACKGROUND

Pancreatic cancer is one of the cancers where anti-PD-L1/PD-1 immunotherapy has been unsuccessful. What confers pancreatic cancer resistance to checkpoint immunotherapy is unknown. The aim of this study is to elucidate the underlying mechanism of PD-L1 expression regulation in the context of pancreatic cancer immune evasion.

METHODS

Pancreatic cancer mouse models and human specimens were used to determine PD-L1 and PD-1 expression and cancer immune evasion. Histone methyltransferase inhibitors, RNAi, and overexpression were used to elucidate the underlying molecular mechanism of PD-L1 expression regulation. All statistical tests were two-sided.

RESULTS

PD-L1 is expressed in 60% to 90% of tumor cells in human pancreatic carcinomas and in nine of 10 human pancreatic cancer cell lines. PD-1 is expressed in 51.2% to 52.1% of pancreatic tumor-infiltrating cytotoxic T lymphocytes (CTLs). Tumors grow statistically significantly faster in FasL-deficient mice than in wild-type mice (P = .03-.001) and when CTLs are neutralized (P = .03-<.001). H3K4 trimethylation (H3K4me3) is enriched in the cd274 promoter in pancreatic tumor cells. MLL1 directly binds to the cd274 promoter to catalyze H3K4me3 to activate PD-L1 transcription in tumor cells. Inhibition or silencing of MLL1 decreases the H3K4me3 level in the cd274 promoter and PD-L1 expression in tumor cells. Accordingly, inhibition of MLL1 in combination with anti-PD-L1 or anti-PD-1 antibody immunotherapy effectively suppresses pancreatic tumor growth in a FasL- and CTL-dependent manner.

CONCLUSIONS

The Fas-FasL/CTLs and the MLL1-H3K4me3-PD-L1 axis play contrasting roles in pancreatic cancer immune surveillance and evasion. Targeting the MLL1-H3K4me3 axis is an effective approach to enhance the efficacy of checkpoint immunotherapy against pancreatic cancer.

Multidimensional Complexity of Cancer. Simple Solutions Are Needed

Cancer is a complex system. Tumor complexity is determined not only by genetic and epigenetic heterogeneity, but also by a huge number of interactions between cancer and normal cells. The heterogeneity and complexity of a tumor causes failure of molecular targeting therapy as a tool for fighting cancer. This review considers the concepts of malignant tumors as organisms that have common characteristics despite all heterogeneity. This leads to the idea that one of the most promising strategies for fighting cancer is the use of the patient's immune system.

The effect of polymorphisms in PD-1 gene on the risk of epithelial ovarian cancer and patients' outcomes

OBJECTIVE

Programmed death-1 (PD-1), an important immunosuppressive molecule, plays a key role in tumor-cell-mediated immune escape. In the present study, we evaluated the effect of PD-1 gene polymorphisms on the risk of developing epithelial ovarian cancer (EOC) and patients' outcomes.

METHODS

A case-control study was performed in 620 EOC patients and 620 control women. Survival data were available for 258 patients who received platinum-based chemotherapy after cytoreductive surgery.

RESULTS

There were significant differences in the genotype and allele distribution frequencies of the PD-1.1 A/G between cases and controls (P=0.028 and P=0.02, respectively). Compared with the AA genotype, AG and GG genotypes may significantly decrease the risk of developing EOC (OR=0.71, 95%CI=0.54-0.94; OR=0.68, 95%CI=0.50-0.94, respectively). We did not find a significant difference in the genotype distribution frequency of the PD-1.5 C/T between cases and controls (P=0.096), but the frequency of T alleles was significantly lower in the EOC cases than that in the controls (P=0.033). Compared to the carriers with C alleles, the carriers with T alleles were at a significantly decreased risk of developing EOC (OR=0.82, 95%CI=0.69-0.98). Survival analysis showed that the two polymorphisms were not associated with patients' outcomes.

CONCLUSIONS

PD-1 gene polymorphisms may be involved in the development of EOC, but not associated with its clinical outcome in EOC patients among northern Chinese women.

Targeting Immune Regulatory Networks to Counteract Immune Suppression in Cancer

The onset of cancer is unavoidably accompanied by suppression of antitumor immunity. This occurs through mechanisms ranging from the progressive accumulation of regulatory immune cells associated with chronic immune stimulation and inflammation, to the expression of immunosuppressive molecules. Some of them are being successfully exploited as therapeutic targets, with impressive clinical results achieved in patients, as in the case of immune checkpoint inhibitors. To limit immune attack, tumor cells exploit specific pathways to render the tumor microenvironment hostile for antitumor effector cells. Local acidification might, in fact, anergize activated T cells and facilitate the accumulation of immune suppressive cells. Moreover, the release of extracellular vesicles by tumor cells can condition distant immune sites contributing to the onset of systemic immune suppression. Understanding which mechanisms may be prevalent in specific cancers or disease stages, and identifying possible strategies to counterbalance would majorly contribute to improving clinical efficacy of cancer immunotherapy. Here, we intend to highlight these mechanisms, how they could be targeted and the tools that might be available in the near future to achieve this goal.

Knockout of MDA-9/Syntenin (SDCBP) expression in the microenvironment dampens tumor-supporting inflammation and inhibits melanoma metastasis

Cancer development and progression to metastasis is a complex process, which largely depends on bidirectional communication between tumor cells and their microenvironment. Melanoma differentiation associated gene-9 (mda-9, also known as Syntenin-1, SDCBP), a gene first cloned by our group, is robustly expressed in multiple cancers including melanoma and contributes to invasion and metastasis in a tumor cell-intrinsic manner. However, the role of MDA-9/Syntenin in the tumor cell-extrinsic microenvironment remains unclear even though MDA-9/Syntenin is ubiquitously expressed in most organs that are active metastatic sites for melanoma, e.g., lung, lymph node, brain, and liver. In this study, we explored the effect of environmental mda-9/syntenin expression on melanoma growth and metastasis using multiple immunocompetent animal models, syngeneic B16 xenograft and intravenous B16 mouse model and a genetically engineered mouse (GEM) model of melanoma. Host-deficient expression of mda-9/syntenin in mice negatively impacted on subcutaneously implanted B16 tumor growth and lung metastasis. Absence of MDA-9/Syntenin in the lung microenvironment suppressed tumor growth by modulating in situ Interleukin 17A (IL17A) expression and impaired the recruitment of myeloid derived suppressor cells (MDSCs) and Th17 cells as compared to genetically wild type animals. Additionally, loss of mda-9/syntenin expression in a spontaneous melanoma model (melanocyte-specific pten loss and BrafV600E mutation) significantly delayed tumor initiation and suppressed metastasis to the lymph nodes and lungs. The present study highlights a novel role of mda-9/syntenin in tumor-promoting inflammation and immune suppression. These observations along with other documented roles of MDA-9/Syntenin in cancer and metastasis support the potential relevance of MDA-9/Syntenin in the carcinogenic process and as a target for developing improved therapies by using either genetic or pharmacologic approaches to treat and prevent melanoma and other cancers.