Leukocyte trafficking in tumor microenvironment

Role of extracellular vesicles in castration-resistant prostate cancer

Prostate cancer (PCa) is a common health threat to men worldwide, and castration-resistant PCa (CRPC) is the leading cause of PCa-related deaths. Extracellular vesicles (EVs) are lipid bilayer compartments secreted by living cells that are important mediators of intercellular communication. EVs regulate the biological processes of recipient cells by transmitting heterogeneous cargoes, contributing to CRPC occurrence, progression, and drug resistance. These EVs originate not only from malignant cells, but also from various cell types within the tumor microenvironment. EVs are widely dispersed throughout diverse biological fluids and are attractive biomarkers derived from noninvasive liquid biopsy techniques. EV quantities and cargoes have been tested as potential biomarkers for CRPC diagnosis, progression, drug resistance, and prognosis; however, technical barriers to their clinical application continue to exist. Furthermore, exogenous EVs may provide tools for new therapies for CRPC. This review summarizes the current evidence on the role of EVs in CRPC.

Clinical advances in analytical profiling of signature lipids: implications for severe non-communicable and neurodegenerative diseases

BACKGROUND

Lipids play key roles in numerous biological processes, including energy storage, cell membrane structure, signaling, immune responses, and homeostasis, making lipidomics a vital branch of metabolomics that analyzes and characterizes a wide range of lipid classes. Addressing the complex etiology, age-related risk, progression, inflammation, and research overlap in conditions like Alzheimer's Disease, Parkinson's Disease, Cardiovascular Diseases, and Cancer poses significant challenges in the quest for effective therapeutic targets, improved diagnostic markers, and advanced treatments. Mass spectrometry is an indispensable tool in clinical lipidomics, delivering quantitative and structural lipid data, and its integration with technologies like Liquid Chromatography (LC), Magnetic Resonance Imaging (MRI), and few emerging Matrix-Assisted Laser Desorption Ionization- Imaging Mass Spectrometry (MALDI-IMS) along with its incorporation into Tissue Microarray (TMA) represents current advances. These innovations enhance lipidomics assessment, bolster accuracy, and offer insights into lipid subcellular localization, dynamics, and functional roles in disease contexts.

AIM OF THE REVIEW

The review article summarizes recent advancements in lipidomic methodologies from 2019 to 2023 for diagnosing major neurodegenerative diseases, Alzheimer's and Parkinson's, serious non-communicable cardiovascular diseases and cancer, emphasizing the role of lipid level variations, and highlighting the potential of lipidomics data integration with genomics and proteomics to improve disease understanding and innovative prognostic, diagnostic and therapeutic strategies.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Clinical lipidomic studies are a promising approach to track and analyze lipid profiles, revealing their crucial roles in various diseases. This lipid-focused research provides insights into disease mechanisms, biomarker identification, and potential therapeutic targets, advancing our understanding and management of conditions such as Alzheimer's Disease, Parkinson's Disease, Cardiovascular Diseases, and specific cancers.

Methionine enkephalin (MENK) protected macrophages from ferroptosis by downregulating HMOX1 and ferritin

OBJECTIVE

The aim of this work was to investigate the immunological effect of MENK by analyzing the protein spectrum and bioinformatics of macrophage RAW264.7, and to explore the relationship between macrophage and ferroptosis.

RESULT

We employed proteomic analysis to identify differentially expressed proteins (DEPs) between macrophages and macrophages intervened by MENK. A total of 208 DEPs were identified. Among these, 96 proteins had upregulated expression and 112 proteins had downregulated expression. Proteomic analysis revealed a significant enrichment of DEPs associated with iron metabolism. The identification of hub genes was conducted using KEGG pathway diagrams and protein-protein interaction (PPI) analysis. The hub genes identified in this study include HMOX1 and Ferritin (FTH and FTL). A correlation was established between HMOX1, FTH, and FTL in the GO and KEGG databases. The results of PCR, WB and immunofluorescence showed that MENK downregulated the level of HMOX1 and FTH.

CONCLUSION

MENK had the potential to become an adjuvant chemotherapy drug by regulating iron metabolism in macrophages, reducing levels of HMOX1 and ferritin. We proposed an innovative research direction on the therapeutic potential of MENK, focusing on the relationship between ferroptosis and macrophage activity.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Microenvironmental regulation in tumor progression: Interactions between cancer-associated fibroblasts and immune cells

The tumor microenvironment (TME), the "soil" on which tumor cells grow, has an important role in regulating the proliferation and metastasis of tumor cells as well as their response to treatment. Cancer-associated fibroblasts (CAFs), as the most abundant stromal cells of the TME, can not only directly alter the immunosuppressive effect of the TME through their own metabolism, but also influence the aggregation and function of immune cells by secreting a large number of cytokines and chemokines, reducing the body's immune surveillance of tumor cells and making them more prone to immune escape. Our study provides a comprehensive review of fibroblast chemotaxis, malignant transformation, metabolic characteristics, and interactions with immune cells. In addition, the current small molecule drugs targeting CAFs have been summarized, including both natural small molecules and targeted drugs for current clinical therapeutic applications. A complete review of the role of fibroblasts in TME from an immune perspective is presented, which has important implications in improving the efficiency of immunotherapy by targeting fibroblasts.

3D bioprinting tumor models mimic the tumor microenvironment for drug screening

Cancer is a severe threat to human life and health and represents the main cause of death globally. Drug therapy is one of the primary means of treating cancer; however, most anticancer medications do not proceed beyond preclinical testing because the conditions of actual human tumors are not effectively mimicked by traditional tumor models. Hence, bionic in vitro tumor models must be developed to screen for anticancer drugs. Three-dimensional (3D) bioprinting technology can produce structures with built-in spatial and chemical complexity and models with accurately controlled structures, a homogeneous size and morphology, less variation across batches, and a more realistic tumor microenvironment (TME). This technology can also rapidly produce such models for high-throughput anticancer medication testing. This review describes 3D bioprinting methods, the use of bioinks in tumor models, and in vitro tumor model design strategies for building complex tumor microenvironment features using biological 3D printing technology. Moreover, the application of 3D bioprinting in vitro tumor models in drug screening is also discussed.

Integrating single-cell RNA-seq and spatial transcriptomics reveals MDK-NCL dependent immunosuppressive environment in endometrial carcinoma

Objectives

The tumor microenvironment (TME) play important roles in progression of endometrial carcinoma (EC). We aimed to assess the cell populations in TME of EC.

Methods

We downloaded datasets of single-cell RNA-seq (scRNA-seq) and spatial transcriptome (ST) for EC from GEO, and downloaded RNA-Seq (FPKM) and clinical data of TCGA-UCEC project from TCGA. The datasets were analyzed using R software.

Results

We obtained 5 datasets of scRNA-seq, 1 of ST and 569 samples of RNA-seq. Totally, 0.2 billion transcripts and 33,408 genes were detected in 33,162 cells from scRNA-seq. The cells were classified into 9 clusters, and EC cells were originated from epithelial cells and ciliated cells. Gene set variation analysis (GSVA) indicated that the pathways enriched in the subclusters of epithelial cells and endothelial cells were significantly different, indicating great heterogeneity in EC. Cell-cell communication analyses showed that EC cells emitted the strongest signals, and endothelial cells received more signals than other cells. Further analysis found that subclusters of 1 and 2 of epithelial cells were showed a more malignant phenotype, which may confer malignant phenotype to subcluster of 0 of endothelial cells through MK pathway by MDL-NCL signal. We also analyzed communications between spatial neighbors with ST data and confirmed the findings on MDL-NCL in cell-cell communication. TCGA and GEO analyses indicated that the expression levels of NCL was inversely correlated with ImmuneScore.

Conclusion

Our study revealed EC cells can confer malignant phenotype to endothelial cells by MDK-NCL signal, and NCL is associated with suppressed immune activity. EC cells may shape TME by inhibiting immune cells and “educating” stromal cells via MDK-NCL signal.

An Angiogenesis-Related lncRNA Signature Is Associated with Prognosis and Tumor Immune Microenvironment in Breast Cancer

Angiogenesis is crucial in the development and progression of tumors. This study examined the relationship between angiogenesis-related lncRNAs (AR-lncRNAs) and breast cancer (BC) immunity and prognosis. We used univariate Cox regression analysis to obtain AR-lncRNAs closely related to BC prognosis. Cluster analysis of BC patients was performed using non-negative matrix factorization (NMF) analysis according to the expression of AR-lncRNAs that were prognostically relevant. An AR-lncRNA risk model (AR-lncM) was created using LASSO regression analysis to predict the prognosis and survival of BC patients. Subsequently, the effect of LINC01614 on cell migration and invasion was verified by Transwell and Western blot assays, and the CCK-8 assay detected its impact on cell sensitivity to tamoxifen. Finally, we obtained 17 AR-lncRNAs from the TCGA database that were closely associated with the prognosis of BC patients. Based on the expression of these AR-lncRNAs, BC patients were divided into five clusters using NMF analysis. Cluster 1 was found to have a better prognosis, higher expression of immune checkpoints, and higher levels of immune cell infiltration. Furthermore, an AR-LncM model was created using ten prognostic-related AR-lncRNAs. The model’s risk predictive performance was validated using survival analysis, timeROC curves, and univariate and multivariate Cox analysis. The most interesting gene in the model, LINC01614, was found to regulate epithelial-mesenchymal transition (EMT) and tamoxifen sensitivity in BC cells, implying that LINC01614 could be a potential therapeutic target for BC patients.

SEVs-mediated miR-6750 transfer inhibits pre-metastatic niche formation in nasopharyngeal carcinoma by targeting M6PR

Reliable detection of circulating small extracellular vesicles (SEVs) and their miRNA cargo has been needed to develop potential specific non-invasive diagnostic and therapeutic marker for cancer metastasis. Here, we detected miR-6750, the precise molecular function of which was largely unknown, was significantly enriched in serum-SEVs from normal volunteers vs. patients with nasopharyngeal carcinoma (NPC). And we determined that miR-6750-SEVs attenuated NPC metastasis. Subsequently, miR-6750-SEVs was proven to inhibit angiogenesis and activate macrophage toward to M1 phenotype to inhibit pre-metastatic niche formation. After analyzing the expression level of miR-6750 in NPC cells, HUVECs and macrophage, we found that once miR-6750 level in NPC cells was close to or higher than normal nasopharyngeal epithelial cells (NP69), miR-6750-SEVs would be transferred from NPC cells to macrophage and then to HUVECs to modulate metastatic niche. Moreover, in vitro assays and BALB/c mouse tumor models revealed that miR-6750 directly targeted mannose 6-phosphate receptor (M6PR). Taken together, our findings revealed that miR-6750-M6PR axis can mediate NPC metastasis by remodeling tumor microenvironment (TME) via SEVs, which give novel sights to pathogenesis of NPC.

The promise of targeting heme and mitochondrial respiration in normalizing tumor microenvironment and potentiating immunotherapy

Cancer immunotherapy shows durable treatment responses and therapeutic benefits compared to other cancer treatment modalities, but many cancer patients display primary and acquired resistance to immunotherapeutics. Immunosuppressive tumor microenvironment (TME) is a major barrier to cancer immunotherapy. Notably, cancer cells depend on high mitochondrial bioenergetics accompanied with the supply of heme for their growth, proliferation, progression, and metastasis. This excessive mitochondrial respiration increases tumor cells oxygen consumption, which triggers hypoxia and irregular blood vessels formation in various regions of TME, resulting in an immunosuppressive TME, evasion of anti-tumor immunity, and resistance to immunotherapeutic agents. In this review, we discuss the role of heme, heme catabolism, and mitochondrial respiration on mediating immunosuppressive TME by promoting hypoxia, angiogenesis, and leaky tumor vasculature. Moreover, we discuss the therapeutic prospects of targeting heme and mitochondrial respiration in alleviating tumor hypoxia, normalizing tumor vasculature, and TME to restore anti-tumor immunity and resensitize cancer cells to immunotherapy.

Drug-Resistance Mechanism and New Targeted Drugs and Treatments of Relapse and Refractory DLBCL

Diffuse large B-cell lymphoma (DLBCL) is the most common aggressive non-Hodgkin's lymphoma (NHL). 30 ~ 40% of DLBCL patients were resistant to the standard R-CHOP regimen or recurrence after remission. It is currently believed that drug resistance is the main cause of the recurrence and refractory of DLBCL (R/R DLBCL). With the increased understanding of DLBCL biology, tumor microenvironment and epigenetics, some new therapies and drugs like molecular and signal pathway target therapy, chimeric antigen receptor (CAR) T-cell therapy, immune checkpoint inhibitors, antibody drug-conjugate and tafasitamab have been used for R/R DLBCL. This article will review the drug resistance mechanism and novel targeted drugs and therapies of DLBCL.

Advances, challenge and prospects in cell-mediated nanodrug delivery for cancer therapy: a review

Nanomedicine offers considerable opportunities to improve drugability and reduce toxicity for tumour therapy. However, the application of nanomedicine has achieved little success in clinical trials due to multiple physiological barriers to drug delivery. Circulating cells are expected to improve the physical distribution of drugs and enhance the therapeutic effect by overcoming various biological barriers in collaboration with nano-drug delivery systems owing to excellent biocompatibility, low immunogenicity and a long-circulation time and strong binding specificity. Nonetheless, we have noticed some limitations in implementing tthe strategy. In this article, we intend to introduce the latest progress in research and application of circulating cell-mediated nano-drug delivery systems, describe the main cell-related drug delivery modes, sum up the relevant points of the transport systems in the process of loading, transport and release, and lastly discuss the advantages, challenges and future development trends in cell-mediated nano-drug delivery.

Drug Resistance: The Role of Exosomal miRNA in the Microenvironment of Hematopoietic Tumors

Extracellular vesicles (EVs), including exosomes, have an important role thanks to their ability to communicate and exchange information between tumor cells and the tumor microenvironment (TME), and have also been associated with communicating anti-cancer drug resistance (DR). The increase in proliferation of cancer cells alters oxygen levels, which causes hypoxia and results in a release of exosomes by the cancer cells. In this review, the results of studies examining the role of exosomal miRNA in DR, and their mechanism, are discussed in detail in hematological tumors: leukemia, lymphoma, and multiple myeloma. In conclusion, we underline the exosome's function as a possible drug delivery vehicle by understanding its cargo. Engineered exosomes can be used to be more specific for personalized therapy.

Extracellular-Vesicle-Based Drug Delivery Systems for Enhanced Antitumor Therapies through Modulating the Cancer-Immunity Cycle

Although immunotherapy harnessing activity of the immune system against tumors has made great progress, the treatment efficacy remains limited in most cancers. Current anticancer immunotherapy is primarily based on T-cell-mediated cellular immunity, which highly relies on efficiency of triggering the cancer-immunity cycle, namely, tumor antigen release, antigen presentation by antigen presenting cells, T cell activation, recruitment and infiltration of T cells into tumors, and recognition and killing of tumor cells by T cells. Unfortunately, these immunotherapies are restricted by inefficient drug delivery and acting on only a single step of the cancer-immunity cycle. Due to high biocompatibility, low immunogenicity, intrinsic cell targeting, and easy chemical and genetic manipulation, extracellular vesicle (EV)-based drug delivery systems are widely used to amplify anticancer immune responses by serving as an integrated platform for multiple drugs or therapeutic strategies to synergistically activate several steps of cancer-immunity cycle. This review summarizes various mechanisms related to affecting cancer-immunity cycle disorders. Meanwhile, preparation and application of EV-based drug delivery systems in modulating cancer-immunity cycle are introduced, especially in the improvement of T cell recruitment and infiltration into tumors. Finally, opportunities and challenges of EV-based drug delivery systems in translational clinical applications are briefly discussed.

Targeting hypoxia-inducible factors for breast cancer therapy: A narrative review

Hypoxia-inducible factors (HIFs), central regulators for cells to adapt to low cellular oxygen levels, are often overexpressed and activated in breast cancer. HIFs modulate the primary transcriptional response of downstream pathways and target genes in response to hypoxia, including glycolysis, angiogenesis and metastasis. They can promote the development of breast cancer and are associated with poor prognosis of breast cancer patients by regulating cancer processes closely related to tumor invasion, metastasis and drug resistance. Thus, specific targeting of HIFs may improve the efficiency of cancer therapy. In this review, we summarize the advances in HIF-related molecular mechanisms and clinical and preclinical studies of drugs targeting HIFs in breast cancer. Given the rapid progression in this field and nanotechnology, drug delivery systems (DDSs) for HIF targeting are increasingly being developed. Therefore, we highlight the HIF related DDS, including liposomes, polymers, metal-based or carbon-based nanoparticles.

Red Blood Cells Protein Profile Is Modified in Breast Cancer Patients

Metastasis is the primary cause of death for most breast cancer (BC) patients who succumb to the disease. During the hematogenous dissemination, circulating tumor cells interact with different blood components. Thus, there are microenvironmental and systemic processes contributing to cancer regulation. We have recently published that red blood cells (RBCs) that accompany circulating tumor cells have prognostic value in metastatic BC patients. RBC alterations are related to several diseases. Although the principal known role is gas transport, it has been recently assigned additional functions as regulatory cells on circulation. Hence, to explore their potential contribution to tumor progression, we characterized the proteomic composition of RBCs from 53 BC patients from stages I to III and IV, compared with 33 cancer-free controls. In this work, we observed that RBCs from BC patients showed a different proteomic profile compared to cancer-free controls and between different tumor stages. The differential proteins were mainly related to extracellular components, proteasome, and metabolism. Embryonic hemoglobins, not expected in adults' RBCs, were detected in BC patients. Besides, lysosome-associated membrane glycoprotein 2 emerge as a new RBCs marker with diagnostic and prognostic potential for metastatic BC patients. Seemingly, RBCs are acquiring modifications in their proteomic composition that probably represents the systemic cancer disease, conditioned by the tumor microenvironment.

Cuprotosis Programmed-Cell-Death-Related lncRNA Signature Predicts Prognosis and Immune Landscape in PAAD Patients

In terms of mortality and survival, pancreatic cancer is one of the worst malignancies. Known as a unique type of programmed cell death, cuprotosis contributes to tumor cell growth, angiogenesis, and metastasis. Cuprotosis programmed-cell-death-related lncRNAs (CRLs) have been linked to PAAD, although their functions in the tumor microenvironment and prognosis are not well understood. This study included data from the TCGA-PAAD cohort. Random sampling of PAAD data was conducted, splitting the data into two groups for use as a training set and test set (7:3). We searched for differentially expressed genes that were substantially linked to prognosis using univariate Cox and Lasso regression analysis. Through the use of multivariate Cox proportional risk regression, a risk-rating system for prognosis was developed. Correlations between the CRL signature and clinicopathological characteristics, tumor microenvironment, immunotherapy response, and chemotherapy sensitivity were further evaluated. Lastly, qRT-PCR was used to compare CRL expression in healthy tissues to that in tumors. Some CRLs are thought to have strong correlations with PAAD outcomes. These CRLs include AC005332.6, LINC02041, LINC00857, and AL117382.1. The CRL-based signature construction exhibited outstanding predictive performance and offers a fresh approach to evaluating pre-immune effectiveness, paving the way for future studies in precision immuno-oncology.

Short-chain L-3-hydroxyacyl-CoA dehydrogenase: A novel vital oncogene or tumor suppressor gene in cancers

The reprogramming of cellular metabolism is frequently linked to tumorigenesis. Glucose, fatty acids, and amino acids are the specific substrates involved in how an organism maintains metabolic equilibrium. The HADH gene codes for the short-chain L-3-hydroxyacyl-CoA dehydrogenase (HADH), a crucial enzyme in fatty acid oxidation that catalyzes the third phase of fatty acid oxidation in mitochondria. Increasing data suggest that HADH is differentially expressed in various types of malignancies and is linked to cancer development and progression. The significance of HADH expression in tumors and its potential mechanisms of action in the onset and progression of certain cancers are summarized in this article. The possible roles of HADH as a target and/or biomarker for the detection and treatment of various malignancies is also described here.

Modulation of diverse oncogenic signaling pathways by oroxylin A: An important strategy for both cancer prevention and treatment

BACKGROUND

Regardless of major advances in diagnosis, prevention and treatment strategies, cancer is still a foreboding cause due to factors like chemoresistance, radioresistance, adverse side effects and cancer recurrence. Therefore, continuous development of unconventional approaches is a prerequisite to overcome foregoing glitches. Natural products have found their way into treatment of serious health conditions, including cancer since ancient times. The compound oroxylin A (OA) is one among those with enormous potential against different malignancies. It is a flavonoid obtained from the several plants such as Oroxylum indicum, Scutellaria baicalensis and S. lateriflora, Anchietea pyrifolia, and Aster himalaicus.

PURPOSE

The main purpose of this study is to comprehensively elucidate the anticancerous effects of OA against various malignancies and unravel their chemosensitization and radiosensitization potential. Pharmacokinetic and pharmacodynamic studies of OA have also been investigated.

METHOD

The literature on antineoplastic effects of OA was searched in PubMed and Scopus, including in vitro and in vivo studies and is summarized based on a systematic review protocol prepared according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The term "oroxylin A" was used in combination with "cancer" and all the title, abstracts and keywords appeared were considered.

RESULTS

In Scopus, a total of 157 articles appeared out of which 103 articles that did not meet the eligibility criteria were eliminated and 54 were critically evaluated. In PubMed, from the 85 results obtained, 26 articles were eliminated and 59 were included in the preparation of this review. Mounting number of studies have illustrated the anticancer effects of OA, and its mechanism of action.

CONCLUSION

OA is a promising natural flavonoid possessing wide range of pleiotropic properties and is a potential anticancer agent. It has a great potential in the treatment of multiple cancers including brain, breast, cervical, colon, esophageal, gall bladder, gastric, hematological, liver, lung, oral, ovarian, pancreatic and skin. However, lack of pharmacokinetic studies, toxicity assessments, and dose standardization studies and adverse effects limit the optimization of this compound as a therapeutic agent.

FABP6 Expression Correlates with Immune Infiltration and Immunogenicity in Colorectal Cancer Cells

Background

Immune checkpoint inhibitors (ICIs) have rapidly revolutionized colorectal cancer (CRC) treatment, but resistance caused by the heterogeneous tumor microenvironment (TME) still presents a challenge. Therefore, it is necessary to characterize TME immune infiltration and explore new targets to improve immunotherapy.

Methods

The compositions of 64 types of infiltrating immune cells and their relationships with CRC patient clinical characteristics were assessed. Differentially expressed genes (DEGs) between “hot” and “cold” tumors were used for functional analysis. A prediction model was constructed to explore the survival of CRC patients treated with and without immunotherapy. Finally, fatty acid-binding protein (FABP6) was selected for in vitro experiments, which revealed its roles in the proliferation, apoptosis, migration, and immunogenicity of CRC tissues and cell lines.

Results

The infiltration levels of several immune cells were associated with CRC tumor stage and prognosis. Different cell types showed the synergistic or antagonism infiltration patterns. Enrichment analysis of DEGs revealed that immune-related signaling was significantly activated in hot tumors, while metabolic process pathways were altered in cold tumors. In addition, the constructed model effectively predicted the survival of CRC patients treated with and without immunotherapy. FABP6 knockdown did not significantly alter tumor cell proliferation, apoptosis, and migration. FABP6 was negatively correlated with immune infiltration, and knockdown of FABP6 increased major histocompatibility complex (MHC) class 1 expression and promoted immune-related chemokine secretion, indicating the immunogenicity enhancement of tumor cells. Finally, knockdown of FABP6 could promote the recruitment of CD8+ T cells.

Conclusion

Collectively, we described the landscape of immune infiltration in CRC and identified FABP6 as a potential immunotherapeutic target for treatment.

Urological cancer organoids, patients' avatars for precision medicine: past, present and future

Urological cancers are common malignant cancers worldwide, with annually increasing morbidity and mortality rates. For decades, two-dimensional cell cultures and animal models have been widely used to study the development and underlying molecular mechanisms of urological cancers. However, they either fail to reflect cancer heterogeneity or are time-consuming and labour-intensive. The recent emergence of a three-dimensional culture model called organoid has the potential to overcome the shortcomings of traditional models. For example, organoids can recapitulate the histopathological and molecular diversity of original cancer and reflect the interaction between cancer and surrounding cells or stroma by simulating tumour microenvironments. Emerging evidence suggests that urine-derived organoids can be generated, which could be a novel non-invasive liquid biopsy method that provides new ideas for clinical precision therapy. However, the current research on organoids has encountered some bottlenecks, such as the lack of a standard culture process, the need to optimize the culture medium and the inability to completely simulate the immune system in vivo. Nonetheless, cell co-culture and organoid-on-a-chip have significant potential to solve these problems. In this review, the latest applications of organoids in drug screening, cancer origin investigation and combined single-cell sequencing are illustrated. Furthermore, the development and application of organoids in urological cancers and their challenges are summarised.

Immune Checkpoint Inhibitors in Cancer Therapy—How to Overcome Drug Resistance?

Simple Summary

Immune checkpoint inhibitors (ICIs) are an important strategy in cancer therapy. However, with the widespread clinical use of ICIs, people gradually found that ICIs may not be effective enough to eliminate tumor tissue for certain patients. The resistance to ICI treatment makes some patients unable to benefit from their antitumor effects. Therefore, it is vital to understand their antitumor and drug resistance mechanisms to better narrow the ICI-resistant patient population. This review outlines the antitumor action sites and mechanisms of different types of ICIs and lists the main reason of ICI resistance based on recent studies. Finally, we propose current and future solutions for resistance to ICIs.

Abstract

Immune checkpoint inhibitors (ICIs), antagonists used to remove tumor suppression of immune cells, have been widely used in clinical settings. Their high antitumor effect makes them crucial for treating cancer after surgery, radiotherapy, chemotherapy, and targeted therapy. However, with the advent of ICIs and their use by a large number of patients, more clinical data have gradually shown that some cancer patients still have resistance to ICI treatment, which makes some patients unable to benefit from their antitumor effect. Therefore, it is vital to understand their antitumor and drug resistance mechanisms. In this review, we focused on the antitumor action sites and mechanisms of different types of ICIs. We then listed the main possible mechanisms of ICI resistance based on recent studies. Finally, we proposed current and future solutions for the resistance of ICIs, providing theoretical support for improving their clinical antitumor effect.

GRHL2 Expression Functions in Breast Cancer Aggressiveness and Could Serve as Prognostic and Diagnostic Biomarker for Breast Cancer

Background

Breast cancer (BC) is the most frequent malignancy in women worldwide and the leading cause of female cancer-associated death in the world. Grainyhead-like 2 (GRHL2) is an important gene involved in human cancer progression. However, the role of GRHL2 in BC is unknown.

Methods

In this study, we used in vitro experiments to verify the role of GRHL2 expression in BC progression. We used 14 databases to analyse the expression level of GRHL2 in BC and its prognostic and diagnostic value. In addition, the correlation between GRHL2 expression and immune cell infiltration and DNA methylation was also analysed.

Results

At the cellular level, overexpression of GRHL2 induced E-cadherin expression in BC cells with a mesenchymal phenotype and resulted in a hybrid epithelial/mesenchymal (E/M) phenotype, which is more strongly correlated with tumour aggressiveness than a pure mesenchymal phenotype. Through analysis of various databases, we found that tumour tissue had a higher expression level of GRHL2. High expression of GRHL2 was associated with worse prognosis of BC patients and indicated that GRHL2 had significant diagnostic value. Grainyhead-like 2 is also related to immune infiltration and regulated by DNA methylation. Furthermore, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) analyses showed that GRHL2-related signalling pathways in BC were related to tumour cell proliferation, invasion, and angiogenesis.

Conclusions

In summary, evidence indicates that GRHL2 can be used as a prognostic and diagnostic biomarker for BC.

Tumor-on-a-chip model for advancement of anti-cancer nano drug delivery system

Despite explosive growth in the development of nano-drug delivery systems (NDDS) targeting tumors in the last few decades, clinical translation rates are low owing to the lack of efficient models for evaluating and predicting responses. Microfluidics-based tumor-on-a-chip (TOC) systems provide a promising approach to address these challenges. The integrated engineered platforms can recapitulate complex in vivo tumor features at a microscale level, such as the tumor microenvironment, three-dimensional tissue structure, and dynamic culture conditions, thus improving the correlation between results derived from preclinical and clinical trials in evaluating anticancer nanomedicines. The specific focus of this review is to describe recent advances in TOCs for the evaluation of nanomedicine, categorized into six sections based on the drug delivery process: circulation behavior after infusion, endothelial and matrix barriers, tumor uptake, therapeutic efficacy, safety, and resistance. We also discuss current issues and future directions for an end-use perspective of TOCs.

Tumor Microenvironment Characterization in Breast Cancer and an Immune Cell Infiltration Score Development, Validation, and Application

The tumor microenvironment (TME) refers to the cellular environment in which tumors exist. An increasing number of reports have emphasized its role in tumor progression, prognosis, relapse, metastasis, and therapeutic response with breast cancer (BRCA). Few studies have revealed a systematic landscape of immune cell infiltration (ICI) in BRCA. In this study, we comprehensively analyzed the immune cells infiltrating TME in BRCA. Three ICI patterns were identified through an unsupervised clustering method and an ICI score was developed by a principal component analysis (PCA). A Kaplan-Meier survival with log-rank test revealed a significant overall survival (OS) difference of BRCA patients with these three ICI patterns. We also found that a high ICI score was characterized by an elevated tumor mutation burden (TMB), effector T-cell infiltration, INF-γ-related cytotoxicity, and cytolytic activity score. An independent cohort validated that this ICI score could be a prognostic indicator for BRCA. Two immunotherapeutic cohorts and two chemotherapeutic cohorts confirmed that patients with higher ICI scores showed significant chemotherapeutic and immunotherapeutic advantages. In summary, these results suggest that the ICI patterns could act as a prognostic indicator and that the ICI score could precisely predict the clinical outcome for BRCA patients.

A Systematic Pan-Cancer Analysis of YY1 Aberrations and their Relationship with Clinical Outcome, Tumor Microenvironment, and Therapeutic Targets

Yin-Yang 1 (YY1) has a crucial function in the development of several malignancies, according to recent research. However, nothing is known about its aberrant expression and prognostic significance in human pan-cancer. We first explored the potential carcinogenic effect of YY1 in 33 cancers using the cancer genome atlas (TCGA) project and gene expression omnibus (GEO) datasets in this research. Then, we contained a variety of elements, for instance, gene expression, the state of survival, gene alterations, protein phosphorylation, immune infiltration, and related cellular pathways, and used a series of bioinformatics methods to investigate the underlying molecular mechanism of YY1 in the etiology or clinical prognosis of various malignancies. In most malignancies, YY1 was expressed at high levels, and the level of YY1 expression was statistically associated with the prognosis of tumor patients. The S118 site of YY1 implied higher phosphorylation expression in breast cancer, colon cancer, uterine corpus endometrial carcinoma (UCEC), and lung adenocarcinoma (LUAD) tumor tissues, but lower phosphorylation levels in ovarian cancer and clear cell carcinoma tumor tissues. For S247, higher phosphorylation levels were found in colon cancer, UCEC, and LUAD tumor tissue, and lower phosphorylation expression was found in clear cell carcinoma tumor tissue. In TCGA database, YY1 expression in BRCA, BRCA-LumA, BRCA-LumB, CESC, CHOL, COAD, ESCA, HNSC, HNSC-HPV-, KIRP, LGG, LIHC, and PAAD tumor tissues was a statistically significant positive connection of the estimated infiltration value of cancer-associated fibroblasts but a negative correlation in TGCT. In addition, the functional mechanism of YY1 also involves viral carcinogenesis and ribonucleic acid (RNA) metabolism related functions. Our first pan-cancer analysis offers a pretty comprehensive knowledge of YY1’s oncogenic involvement in various cancers.

Exosome-Derived Non-Coding RNAs in the Tumor Microenvironment of Colorectal Cancer: Possible Functions, Mechanisms and Clinical Applications

Colorectal cancer (CRC) is the second leading cause of cancer death and the third most prevalent malignancy. Colorectal tumors exchange information with the surrounding environment and influence each other, which collectively constitutes the tumor microenvironment (TME) of CRC. Many studies have shown that exosome-derived non-coding RNAs (ncRNAs) play important roles in various pathophysiological processes by regulating the TME of CRC. This review summarizes recent findings on the fundamental roles of exosomal ncRNAs in angiogenesis, vascular permeability, tumor immunity, tumor metabolism and drug resistance. Certainly, the in-depth understanding of exosomal ncRNAs will provide comprehensive insights into the clinical application of these molecules against CRC.

From Tumor Cells to Endothelium and Gut Microbiome: A Complex Interaction Favoring the Metastasis Cascade

Metastasis is a complicated process through which tumor cells disseminate to distant organs and adapt to novel tumor microenvironments. This multi-step cascade relies on the accumulation of genetic and epigenetic alterations within the tumor cells as well as the surrounding non-tumor stromal cells. Endothelial cells constitute a major player in promoting metastasis formation either by inducing the growth of tumor cells or by directing them towards dissemination in the blood or lymph. In fact, the direct and indirect interactions between tumor and endothelial cells were shown to activate several mechanisms allowing cancer cells’ invasion and extravasation. On the other side, gastrointestinal cancer development was shown to be associated with the disruption of the gut microbiome. While several proposed mechanisms have been investigated in this regard, gut and tumor-associated microbiota were shown to impact the gut endothelial barrier, increasing the dissemination of bacteria through the systemic circulation. This bacterial dislocation allows the formation of an inflammatory premetastatic niche in the distant organs promoting the metastatic cascade of primary tumors. In this review, we discuss the role of the endothelial cells in the metastatic cascade of tumors. We will focus on the role of the gut vascular barrier in the regulation metastasis. We will also discuss the interaction between this vascular barrier and the gut microbiota enhancing the process of metastasis. In addition, we will try to elucidate the different mechanisms through which this bacterial dislocation prepares the favorable metastatic niche at distant organs allowing the dissemination and successful deposition of tumor cells in the new microenvironments. Finally, and given the promising results of the studies combining immune checkpoint inhibitors with either microbiota alterations or anti-angiogenic therapy in many types of cancer, we will elaborate in this review the complex interaction between these 3 factors and their possible therapeutic combination to optimize response to treatment.

Pan-Cancer Characterization of Intratumoral Autonomic Innervation in 32 Cancer Types in the Cancer Genome Atlas

Simple Summary

There have been growing interests in the roles of intratumoral innervation of the autonomic nervous system (ANS) as a mechanism linking psychosocial stress, β-adrenergic signaling pathways, and poor cancer outcomes, and a potential target for therapeutic purpose. Our current knowledge is being limited by the few cancer types where intratumoral ANS have been studied; it remains to be determined the extent of this mechanism existing in different cancer types. Our study provided the first pan-cancer characterization of intratumoral innervation across 32 cancer types, and further, their relationships with tumor histopathological and molecular characteristics and survival outcomes. We found wide variations in intratumoral ANS expression both within and across cancer types. The association of ANS signatures with tumor histopathological characteristics and survival outcomes also varied by cancer type. Our findings suggest that the potential benefits of cancer therapies targeting β-adrenergic receptor-mediated stress signaling pathways are likely dependent on cancer type.

Abstract

Over the past two decades, multiple studies have demonstrated the important role that the autonomic nervous system (ANS) plays in tumorigenesis and cancer progression. However, the mechanisms by which this process occurs have only recently begun to be elucidated. Further, the extent of autonomic innervation in various cancer types and its effects on tumor molecular, immunological, and histopathological features, as well as on patient outcomes, are not yet fully characterized. In this study, we analyzed intratumoral ANS gene expression signatures, including overall intratumoral neuron growth and sympathetic and parasympathetic markers, across 32 cancer types using tumor transcriptomic and clinical annotation data available from The Cancer Genome Atlas (TCGA). Our analysis revealed wide variations in intratumoral ANS expression both within and across cancer types. The association of ANS signatures with tumor histopathological characteristics and survival outcomes also varied by cancer type. We found intratumoral ANS expression to be commonly correlated with angiogenesis, TGF-β signaling, and immunosuppression in the tumor microenvironment of many cancer types, which provide mechanistic insights into the involvement of intratumoral innervation in cancer development and progression. Our findings suggest that the potential benefits of cancer therapies targeting β-adrenergic receptor-mediated stress signaling pathways are likely dependent on cancer type.

The role of autophagy in initiation, progression, TME modification, diagnosis, and treatment of esophageal cancers

Autophagy is a highly conserved metabolic process with a cytoprotective function. Autophagy is involved in cancer, infection, immunity, and inflammation and may be a potential therapeutic target. Increasing evidence has revealed that autophagy has primary implications for esophageal cancer, including its initiation, progression, tumor microenvironment (TME) modification, diagnosis, and treatment. Notably, autophagy displayed excellent application potential in radiotherapy combined with immunotherapy. Radiotherapy combined with immunotherapy is a new potential therapeutic strategy for cancers, including esophageal cancer. Autophagy modulators can work as adjuvant enhancers in radiotherapy or immunotherapy of cancers. This review highlights the most recent data related to the role of autophagy regulation in esophageal cancer.

Hepatocellular Carcinoma Differentiation: Research Progress in Mechanism and Treatment

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. Although progress has been made in diagnosis and treatment, morbidity and mortality continue to rise. Chronic liver disease and liver cirrhosis are still the most important risk factors for liver cancer. Although there are many treatments, it can only be cured by orthotopic liver transplantation (OLT) or surgical resection. And the worse the degree of differentiation, the worse the prognosis of patients with liver cancer. Then it can be considered that restoring a better state of differentiation may improve the prognosis. The differentiation treatment of liver cancer is to reverse the dedifferentiation process of hepatocytes to liver cancer cells by means of drugs, improve the differentiation state of the tumor, and restore the normal liver characteristics, so as to improve the prognosis. Understanding the mechanism of dedifferentiation of liver cancer can provide ideas for drug design. Liver enrichment of transcription factors, imbalance of signal pathway and changes of tumor microenvironment can promote the occurrence and development of liver cancer, and restoring its normal level can inhibit the malignant behavior of tumor. At present, some drugs have been proved to be effective, but more clinical data are needed to support the effectiveness and reliability of drugs. The differentiation treatment of liver cancer is expected to become an important part of the treatment of liver cancer in the future.

Comprehensive Analysis of the PROSER2-AS1-Related ceRNA Network and Immune Cell Infiltration in Papillary Thyroid Carcinoma

Background

Papillary thyroid carcinoma (PTC) is a malignant tumor of the endocrine system, and distant metastasis leads to poor prognosis for patients with PTC. The competitive endogenous RNA (ceRNA) network and tumor-infiltrating immune cells might participate in tumor prognosis and distant metastasis. However, few studies have focused on ceRNAs and immune cells in PTC.

Methods

We identified differentially expressed lncRNAs (DELs) using the GEO2R tool of the GEO database. Through comprehensive analysis, we selected lncRNA PROSER2-AS1 and constructed a PROSER2-AS1-mediated ceRNA network. Survival was analyzed with a Kaplan-Meier (KM) curve. Gene set enrichment analysis (GSEA) was performed to determine the function of PROSER2-AS1 in the ceRNA network using TCGA database. Moreover, the relationship between PROSER2-AS1 and immune cell infiltration was analyzed with ssGSEA using the “GSVA” package in R.

Results

Comprehensive analysis of the GSE66783 dataset revealed 105 significantly differentially expressed lncRNAs. Univariate and multivariate Cox regression analyses were performed to assess the prognostic significance of the DELs, and we identified lncRNA PROSER2-AS1 as an independent factor for prognosis in PTC (p < 0.05). Considering the online tools LncRNASNP2 and miRWalk3.0, we constructed a PROSER2-AS1-related ceRNA network. Furthermore, the GSEA results suggested that PROSER2-AS1 may be involved in immune cell infiltration and that PROSER2-AS1 was correlated with 14 types of tumor-infiltrating immune cells. PROSER2-AS1 might function through TGFBR3.

Conclusion

lncRNA PROSER2-AS1 and related mRNAs (TGFBR3) may be potential prognostic biomarkers in PTC and may correlate with immune infiltrates.

Analysis of the key ligand receptor CADM1_CADM1 in the regulation of thyroid cancer based on scRNA-seq and bulk RNA-seq data

INTRODUCTION

Advanced papillary thyroid cancer (PTC) has a poor prognosis, 60~70% of which become radio iodine refractory (RAI-R), but the molecular markers that assess PTC progress to advanced PTC remain unclear. Meanwhile, current targeted therapies are badly effective due to drug resistance and adverse side effects. Ligand-receptor pairs (L/R pairs) play an important role in the interactions between tumor cells and other cells in the tumor microenvironment (TME). Nowadays, therapies targeting ligand-receptor pairs in the TME are advancing rapidly in the treatment of advanced cancers. However, therapies targeting L/R pairs applied to advanced PTC remains challenging because of limited knowledge about L/R pairs in PTC.

METHODS

We screened the critical L/R pair: CADM1-CADM1 using 65311 single-cell RNA sequencing (scRNA-seq) samples from 7 patients in different stage of PTC and bulk RNA-seq datasets containing data from 487 tumor samples and 58 para-carcinoma samples. Moreover, the expression levels of CADM1-CADM1 was assessed by quantitative real time polymerase chain reaction (qRT-PCR) and the function was analyzed using Transwell immigration assay.

RESULTS

We found that CADM1_CADM1 could be regarded as a biomarker representing a good prognosis of PTC. In addition, the high expression of CADM1_CADM1 can strongly increase the sensitivity of many targeted drugs, which can alleviate drug resistance. And the results of qRT-PCR showed us that the expression of CADM1_CADM1 in PTC was down-regulated and overexpression of CADM1 could suppresses tumor cell invasion migration.

CONCLUSION

Our study identified that CADM1_CADM1 played an essential role in the progression of PTC for the first time and our findings provide a new potential prognostic and therapeutic ligand-receptor pair for advanced PTC.

Structural Biology of the Tumor Microenvironment

Cancers can be described as "rogue organs" (Balkwill FR, Capasso M, Hagemann T, J Cell Sci 125:5591-5596, 2012) because they are composed of multiple cell types and tissues. The transformed cells can recruit and alter healthy cells from surrounding tissues for their own benefit. It is these interactions that create the tumor microenvironment (TME). The TME describes the cells, factors, and extracellular matrix proteins that make up the tumor and the area around it; the biology of the TME influences tumor progression. Changes in the TME can lead to the growth and development of the tumor, the death of the tumor, or tumor metastasis. Metastasis is the process by which cancer spreads from its initial site to a different part of the body. Metastasis occurs when cancer cells enter the circulatory system or lymphatic system after they break away from a tumor. Once the cells leave, they can travel to a different part of the body and form new tumors. Therefore, understanding the TME is critical to fully understand cancer and find a way to successfully combat it. Knowledge of the TME can better inform researchers of the ability of potential therapies to reach tumor cells. It can also give researchers potential targets to kill the tumor. Instead of directly killing the cancer cells, therapies can target an aspect of the TME which could then halt tumor development or lead to tumor death. In other cases, targeting another aspect of the TME could make it easier for another therapy to kill the cancer cells, for example, using nanoparticles with collagenases to target the collagen in the surrounding environment to expose the cancer cells to drugs (Zinger A, et al, ACS Nano 13(10):11008-11021, 2019).The TME can be split simply into cells and the structural matrix. Within these groups are fibroblasts, structural proteins, immune cells, lymphocytes, bone marrow-derived inflammatory cells, blood vessels, and signaling molecules (Spill F, et al, Curr Opin Biotechnol 40:41-48, 2016; Del Prete A, et al, Curr Opin Pharmacol 35:40-47, 2017; Arneth B, Medicina (Kaunas) 56(1), 2019). From structure to providing nutrients for growth, each of these components plays a critical role in tumor maintenance. Together these components impact cancer growth, development, and resistance to therapies (Hanahan D, Coussens LM, Cancer Cell 21:309-322, 2012). In this chapter, we will describe the TME and express the importance of the cellular and structural elements of the TME.

Basics of immunotherapy for epithelial ovarian cancer

Epithelial ovarian cancer (EOC) is the most lethal of all gynecological cancers. Despite excellent responses to standard treatment in approximately 70% of patients, most of them will relapse within 5 years of initial treatment and many of them will develop chemotherapy-resistant disease. It is then important to find other means of treatment for these patients such as immunotherapy or targeted therapy. To understand immunotherapy, it is important to explain the dynamic interplay between cancer and the immune system. Compared to traditional tumor therapies, immunotherapy acts primarily on the immune system or the tumor microenvironment but not directly on the tumor cells, and it may also promote synergistic anti-tumor actions as part of a combined treatment. The aim of this narrative review is to provide a basic understanding of immunotherapy the interest of this treatment in EOC, and to present the main ongoing studies that could change patient management in the future.

Identification of prognostic biomarkers associated with tumor microenvironment in ceRNA network for esophageal squamous cell carcinoma: a bioinformatics study based on TCGA database

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer in the world with high incidence rate and poor prognosis. Infiltrated immune and stromal cells are vital components of tumor microenvironment (TME) and have a significant impact on the progression of ESCC. The competitive endogenous RNA (ceRNA) hypothesis has been proved important in the molecular biological mechanisms of tumor development. However, there are few studies on the relationship between ceRNA and ESCC TME.

METHODS

The proportion of tumor-infiltrating immune cells and the amount of stromal and immune cells in ESCC cases were calculated from The Cancer Genome Atlas database using the CIBERSORT and ESTIMATE calculation methods. After stratified identification of differentially expressed genes, WGCNA and miRNA prediction system were applied to construct ceRNA network. Finally, PPI network and survival analysis were selected to discriminate prognostic signature. And the results were verified in two independent groups from Gene Expression Omnibus and Lanzhou, China.

RESULTS

We found that high Stromal and ESTIMATE scores were significantly associated with poor overall survival. Three TME-related key prognostic genes were screened, namely, LCP2, CD86, SLA. And the expression of them was significantly correlated with infiltrated immunocytes. It is also found that ESTIMATE Score and the expression of CD86 were both related to TNM system of ESCC.

CONCLUSIONS

We identified three novel TME-related prognostic markers and their lncRNA-miRNA-mRNA pathway in ESCC patients, which may provide new strategies for the targeted therapy.

Caveolin1: its roles in normal and cancer stem cells

PURPOSE

Stem cells are characterized by the capability of self-renewal and multi-differentiation. Normal stem cells, which are important for tissue repair and tissue regeneration, can be divided into embryonic stem cells (ESCs) and somatic stem cells (SSCs) depending on their origin. As a subpopulation of cells within cancer, cancer stem cells (CSCs) are at the root of therapeutic resistance. Tumor-initiating cells (TICs) are necessary for tumor initiation. Caveolin1 (Cav1), a membrane protein located at the caveolae, participates in cell lipid transport, cell migration, cell proliferation, and cell signal transduction. The purpose of this review was to explore the relationship between Cav1 and stem cells.

RESULTS

In ESCs, Cav1 is beneficial for self-renewal, proliferation, and migration. In SSCs, Cav1 exhibits positive or/and negative effects on stem cell self-renewal, differentiation, proliferation, migration, and angiogenic capacity. Cav1 deficiency impairs normal stem cell-based tissue repair. In CSCs, Cav1 inhibits or/and promotes CSC self-renewal, differentiation, invasion, migration, tumorigenicity ability, and CSC formation. And suppressing Cav1 promotes chemo-sensitivity in CSCs and TICs.

CONCLUSION

Cav1 shows dual roles in stem cell biology. Targeting the Cav1-stem cell axis would be a new way for tissue repair and cancer drug resistance.

Differences in Immunological Landscape between EGFR-Mutated and Wild-Type Lung Adenocarcinoma

Recent clinical trials of lung adenocarcinoma with immune checkpoint inhibitors revealed that lung adenocarcinoma patients with EGFR mutations have a poor response to immunotherapy. However, the mechanisms have not been addressed. We performed immunohistochemistry analyses of resected lung adenocarcinoma tissues with and without EGFR mutations to investigate and compare the characteristics of the tumor microenvironment (TME). We retrospectively enrolled a total of 323 lung adenocarcinoma patients (164 had EGFR mutations), and their corresponding tissue samples were analyzed by the EGFR mutation test and immunohistochemistry. We selected the markers of the immune checkpoint molecule (PD1, PD-L1, and LAG-3) and immune cell (CD3, CD4, CD8, and Foxp3) as markers of the tumor microenvironment. Our results revealed that patients had a distinct tumor microenvironment between EGFR-mutant and wild-type lung adenocarcinomas; the expression of CD3, CD4, PD-L1, and Foxp3 in EGFR-mutant tumors was significantly higher than that in wild-type tumors, while the expression of LAG3 and PD-1 showed a positive correlation with EGFR-wild-type tumors. In survival analysis, EGFR-wild-type patients had longer disease-free survival (DFS) than EGFR-mutant patients (P = 0.0065). Our research demonstrates significant differences in tumor microenvironment composition between EGFR-mutant and wild-type patients. Our findings provide novel evidence that contributes to understanding the mechanism underlying the poor efficacy of immune checkpoint inhibitors.

Potential Strategies to Improve the Effectiveness of Drug Therapy by Changing Factors Related to Tumor Microenvironment

A tumor microenvironment (TME) is composed of various cell types and extracellular components. It contains tumor cells and is nourished by a network of blood vessels. The TME not only plays a significant role in the occurrence, development, and metastasis of tumors but also has a far-reaching impact on the effect of therapeutics. Continuous interaction between tumor cells and the environment, which is mediated by their environment, may lead to drug resistance. In this review, we focus on the key cellular components of the TME and the potential strategies to improve the effectiveness of drug therapy by changing their related factors.

Establishment of Three-Dimensional Bioprinted Bladder Cancer-on-a-Chip with a Microfluidic System Using Bacillus Calmette-Guérin

Immunotherapy of bladder cancer is known to have favorable effects, although it is difficult to determine which patients will show a good response because of the different tumor microenvironments (TME). Here, we developed a bladder cancer-on-a-chip (BCOC) to mimic the TME using three-dimensional (3D) bioprinting and microfluidic technology. We fabricated a T24 and a 5637-cell line-based BCOC that also incorporated MRC-5, HUVEC, and THP-1 cells. We evaluated the effects of TME and assessed the immunologic reactions in response to different concentrations of Bacillus Calmette–Guérin (BCG) via live/dead assay and THP-1 monocytic migration, and concentrations of growth factors and cytokines. The results show that cell viability was maintained at 15% filling density in circle-shaped cell constructs at 20 μL/min microfluidic flow rate. A 3D co-culture increased the proliferation of BCOCs. We found that the appropriate time to evaluate the viability of BCOC, concentration of cytokines, and migration of monocytes was 6 h, 24 h, and three days after BGC treatment. Lastly, the immunotherapeutic effects of BCOC increased according to BCG dosage. To predict effects of immunotherapeutic agent in bladder cancer, we constructed a 3D bioprinted BCOC model. The BCOC was validated with BCG, which has been proven to be effective in the immunotherapy of bladder cancer.

Construction of a DLBCL Prognostic Signature Based on Tumor Microenvironment

BACKGROUNDS

Diffuse large B-cell lymphoma (DLBCL) is a common curable non-Hodgkin's lymphoma. Patients with this disease can be cured after the R-CHOP immunochemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). Nonetheless, most cured patients will relapse again and have dismal prognosis. In this study, we aim to identify a potential biomarker by analyzing gene expression data, and to predict patient's survival rate by constructing a risk model.

METHODS

Firstly, mRNA chip data (GSE87371) and clinical data of DLBCL patients were obtained from Gene Expression Omnibus (GEO). Samples were scored with estimate package. The obtained stromal score (P < 0.05) and ESTIMATE score (P < 0.05) were significantly correlated with the prognosis. Differentially expressed genes (DEGs) screened through the above two scoring methods were intersected and 279 DEGs were obtained. Next, five feature genes (CD163, CLEC4A, COL15A1, GABRB2, IFIT3) were identified by univariate Cox, LASSO and multivariate Cox regression analyses to establish a risk evaluation model. Thereafter, the 5-gene risk model was validated on a validation set. ROC and survival analyses were performed to assess the performance of the model.

RESULTS

Further analysis showed that the risk model was capable of independently determining the prognosis of patients, and a nomogram was sequentially established.

CONCLUSIONS

Authors screened DEGs related to ESTIMATE and stromal scores from GEO database, and established a 5-gene prognostic signature through Cox regression analysis and LASSO analysis. The risk model and nomogram will help individuals accurately predict the prognosis of DLBCL patients.

Angiogenic Properties of NK Cells in Cancer and Other Angiogenesis-Dependent Diseases

The pathogenesis of many serious diseases, including cancer, is closely related to disturbances in the angiogenesis process. Angiogenesis is essential for the progression of tumor growth and metastasis. The tumor microenvironment (TME) has immunosuppressive properties, which contribute to tumor expansion and angiogenesis. Similarly, the uterine microenvironment (UME) exerts a tolerogenic (immunosuppressive) and proangiogenic effect on its cells, promoting implantation and development of the embryo and placenta. In the TME and UME natural killer (NK) cells, which otherwise are capable of killing target cells autonomously, enter a state of reduced cytotoxicity or anergy. Both TME and UME are rich with factors (e.g., TGF-β, glycodelin, hypoxia), which support a conversion of NK cells to the low/non-cytotoxic, proangiogenic CD56^brightCD16^low phenotype. It is plausible that the phenomenon of acquiring proangiogenic and low cytotoxic features by NK cells is not only limited to cancer but is a common feature of different angiogenesis-dependent diseases (ADDs). In this review, we will discuss the role of NK cells in angiogenesis disturbances associated with cancer and other selected ADDs. Expanding the knowledge of the mechanisms responsible for angiogenesis and its disorders contributes to a better understanding of ADDs and may have therapeutic implications.

Continuous Inflammatory Stimulation Leads via Metabolic Plasticity to a Prometastatic Phenotype in Triple-Negative Breast Cancer Cells

Chronic inflammation promotes cancer progression by affecting the tumor cells and their microenvironment. Here, we demonstrate that a continuous stimulation (~6 weeks) of triple-negative breast tumor cells (TNBC) by the proinflammatory cytokines tumor necrosis factor α (TNFα) + interleukin 1β (IL-1β) changed the expression of hundreds of genes, skewing the cells towards a proinflammatory phenotype. While not affecting stemness, the continuous TNFα + IL-1β stimulation has increased tumor cell dispersion and has induced a hybrid metabolic phenotype in TNBC cells; this phenotype was indicated by a transcription-independent elevation in glycolytic activity and by increased mitochondrial respiratory potential (OXPHOS) of TNBC cells, accompanied by elevated transcription of mitochondria-encoded OXPHOS genes and of active mitochondria area. The continuous TNFα + IL-1β stimulation has promoted in a glycolysis-dependent manner the activation of p65 (NF-κB), and the transcription and protein expression of the prometastatic and proinflammatory mediators sICAM-1, CCL2, CXCL8 and CXCL1. Moreover, when TNBC cells were stimulated continuously by TNFα + IL-1β in the presence of a glycolysis inhibitor, their conditioned media had reduced ability to recruit monocytes and neutrophils in vivo. Such inflammation-induced metabolic plasticity, which promotes prometastatic cascades in TNBC, may have important clinical implications in treatment of TNBC patients.

The Role of V-Domain Ig Suppressor of T Cell Activation (VISTA) in Cancer Therapy: Lessons Learned and the Road Ahead

Immune checkpoints (ICs) have pivotal roles in regulating immune responses. The inhibitory ICs in the tumor microenvironment (TME) have been implicated in the immune evasion of tumoral cells. Therefore, identifying and targeting these inhibitory ICs might be critical for eliminating tumoral cells. V-domain immunoglobulin suppressor of T cell activation (VISTA) is a novel inhibitory IC that is expressed on myeloid cells, lymphoid cells, and tumoral cells; therefore, VISTA can substantially regulate innate and adaptive anti-tumoral immune responses. Besides, growing evidence indicates that VISTA blockade can enhance the sensitivity of tumoral cells to conventional IC-based immunotherapy, e.g., cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. In this regard, the current study aimed to review the current evidence about the structure and expression pattern of VISTA, its role in TME, the clinicopathological significance of VISTA, and its prognostic values in various cancers. Besides, this review intended to collect the lessons from the recent pre-clinical and clinical studies and propose a strategy to overcome tumor immune-resistance states.

The Tumour Vasculature as a Target to Modulate Leucocyte Trafficking

Simple Summary

Tumour blood vessels, characterised by abnormal morphology and function, create an immunosuppressive tumour microenvironment via restricting the appropriate leucocyte subsets trafficking. Strategies to trigger phenotypic alteration in tumour vascular system to resemble normal vascular system, named vascular normalisation, promote effective trafficking of leucocytes into tumours through enhancing the interactions between leucocytes and endothelial cells. This review specifically demonstrates how targeting tumour blood vessels modulates the critical steps of leucocyte trafficking. Furthermore, selective regulation of leucocyte subsets trafficking in tumours can be achieved by vasculature-targeting strategies, contributing to improved immunotherapy and thereby delayed tumour progression.

Abstract

The effectiveness of immunotherapy against solid tumours is dependent on the appropriate leucocyte subsets trafficking and accumulating in the tumour microenvironment (TME) with recruitment occurring at the endothelium. Such recruitment involves interactions between the leucocytes and the endothelial cells (ECs) of the vessel and occurs through a series of steps including leucocyte capture, their rolling, adhesion, and intraluminal crawling, and finally leucocyte transendothelial migration across the endothelium. The tumour vasculature can curb the trafficking of leucocytes through influencing each step of the leucocyte recruitment process, ultimately producing an immunoresistant microenvironment. Modulation of the tumour vasculature by strategies such as vascular normalisation have proven to be efficient in facilitating leucocyte trafficking into tumours and enhancing immunotherapy. In this review, we discuss the underlying mechanisms of abnormal tumour vasculature and its impact on leucocyte trafficking, and potential strategies for overcoming the tumour vascular abnormalities to boost immunotherapy via increasing leucocyte recruitment.

Persistent Inflammatory Stimulation Drives the Conversion of MSCs to Inflammatory CAFs That Promote Pro-Metastatic Characteristics in Breast Cancer Cells

The pro-inflammatory cytokines tumor necrosis factor α (TNFα) and interleukin 1β (IL-1β) are expressed simultaneously and have tumor-promoting roles in breast cancer. In parallel, mesenchymal stem cells (MSCs) undergo conversion at the tumor site to cancer-associated fibroblasts (CAFs), which are generally connected to enhanced tumor progression. Here, we determined the impact of consistent inflammatory stimulation on stromal cell plasticity. MSCs that were persistently stimulated by TNFα + IL-1β (generally 14-18 days) gained a CAF-like morphology, accompanied by prominent changes in gene expression, including in stroma/fibroblast-related genes. These CAF-like cells expressed elevated levels of vimentin and fibroblast activation protein (FAP) and demonstrated significantly increased abilities to contract collagen gels. Moreover, they gained the phenotype of inflammatory CAFs, as indicated by the reduced expression of α smooth muscle actin (αSMA), increased proliferation, and elevated expression of inflammatory genes and proteins, primarily inflammatory chemokines. These inflammatory CAFs released factors that enhanced tumor cell dispersion, scattering, and migration; the inflammatory CAF-derived factors elevated cancer cell migration by stimulating the chemokine receptors CCR2, CCR5, and CXCR1/2 and Ras-activating receptors, expressed by the cancer cells. Together, these novel findings demonstrate that chronic inflammation can induce MSC-to-CAF conversion, leading to the generation of tumor-promoting inflammatory CAFs.

Targeting the MDSCs of Tumors In Situ With Inhibitors of the MAPK Signaling Pathway to Promote Tumor Regression

Myeloid-derived suppressor cells (MDSCs) are one of the major components of the tumor microenvironment. Evidence has shown differences in the functions and fates of MDSCs in the tumor tissue and the periphery. However, the exact mechanism that regulates MDSC function has not been completely clarified. In this study, we performed RNA sequencing of MDSCs derived from the spleen and tumor. Based on the results of our RNA-seq analysis, mitogen-activated protein kinases (MAPK) were significantly increased in tumor polymorphonuclear MDSCs (PMN-MDSCs) and monocytic MDSCs (M-MDSCs). Subsequently, 3 major MAPK pathways, including extracellular signal-regulated protein kinases (ERK), p38 and c-Jun NH2-terminal kinases (JNK), were studied to analyze the role of MAPKs in MDSCs. The ERK 1/2 inhibitor SCH772984 and the JNK inhibitor SP600125 significantly increased the apoptosis of both PMN-MDSCs and M-MDSCs in vitro. In addition, SCH772984 exerted a strong effect on inhibiting tumor growth. The flow cytometry analysis showed significant increases in the ratio of M1:M2 tumor-associated macrophages, meanwhile the number of CD4⁺, CD8⁺, CD4⁺CD69⁺ and CD8⁺CD69⁺ lymphocytes were increased after SCH772984 treatment. Our findings established the effect of MAPKs on the tumor microenvironment via MDSCs and may facilitate the development of new antitumor strategies.

Interleukin-34-CSF1R Signaling Axis Promotes Epithelial Cell Transformation and Breast Tumorigenesis

IL-34 has been recently identified as a ligand for CSF1R that regulates various cellular processes including cell proliferation, survival, and differentiation. Although the binding of IL-34 to CSF1R modulates several cancer-driving signaling pathways, little is known about the role of IL-34/CSF1R signaling in breast cancer. Herein, we report that IL-34 induces epithelial cell transformation and breast tumorigenesis through activation of MEK/ERK and JNK/c-Jun pathways. IL-34 increased the phosphorylation of MEK1/2, ERK1/2, JNK1/2, and c-Jun through CSF1R in mouse skin epidermal JB6 C141 cells and human breast cancer MCF7 cells. IL-34 enhanced c-Fos and c-Jun promoter activity, resulting in increased AP-1 transactivation activity in JB6 Cl41 and MCF7 cells. Moreover, PIN1 enhanced IL-34-induced phosphorylation of MEK1/2, ERK1/2, JNK1/2, and c-Jun in JB6 Cl41 and MCF7 cells. Inhibition of PIN1 using juglone prevented the IL-34-induced transformation of JB6 C141 cells. Similarly, silencing of PIN1 reduced the IL-34-induced tumorigenicity of MCF7 cells. Consistent with these results, the synergistic model showed that treatment with juglone suppressed the IL-34-induced growth of tumors formed by 4T1 cells in BALB/c mice. Our study demonstrates the role of IL-34-induced MEK/ERK and JNK/c-Jun cascades in breast cancer and highlights the regulatory role of PIN1 in IL-34-induced breast tumorigenesis.

Crosstalk between Macrophages, T Cells, and Iron Metabolism in Tumor Microenvironment

Leukocytes, including macrophages and T cells, represent key players in the human immune system, which plays a considerable role in the development and progression of tumors by immune surveillance or immune escape. Boosting the recruitment of leukocytes into the tumor microenvironment and promoting their antitumor responses have been hot areas of research in recent years. Although immunotherapy has manifested a certain level of success in some malignancies, the overall effectiveness is far from satisfactory. Iron is an essential trace element required in multiple, normal cellular processes, such as DNA synthesis and repair, cellular respiration, metabolism, and signaling, while dysregulated iron metabolism has been declared one of the metabolic hallmarks of malignant cancer cells. Furthermore, iron is implicated in the modulation of innate and adaptive immune responses, and elucidating the targeted regulation of iron metabolism may have the potential to benefit antitumor immunity and cancer treatment. In the present review, we briefly summarize the roles of leukocytes and iron metabolism in tumorigenesis, as well as their crosstalk in the tumor microenvironment. The combination of immunotherapy with targeted regulation of iron and iron-dependent regulated cell death (ferroptosis) may be a focus of future research.

Inflammation-Driven Breast Tumor Cell Plasticity: Stemness/EMT, Therapy Resistance and Dormancy

Cellular heterogeneity poses an immense therapeutic challenge in cancer due to a constant change in tumor cell characteristics, endowing cancer cells with the ability to dynamically shift between states. Intra-tumor heterogeneity is largely driven by cancer cell plasticity, demonstrated by the ability of malignant cells to acquire stemness and epithelial-to-mesenchymal transition (EMT) properties, to develop therapy resistance and to escape dormancy. These different aspects of cancer cell remodeling are driven by intrinsic as well as by extrinsic signals, the latter being dominated by factors of the tumor microenvironment. As part of the tumor milieu, chronic inflammation is generally regarded as a most influential player that supports tumor development and progression. In this review article, we put together recent findings on the roles of inflammatory elements in driving forward key processes of tumor cell plasticity. Using breast cancer as a representative research system, we demonstrate the critical roles played by inflammation-associated myeloid cells (mainly macrophages), pro-inflammatory cytokines [such as tumor necrosis factor α (TNFα) and interleukin 6 (IL-6)] and inflammatory chemokines [primarily CXCL8 (interleukin 8, IL-8) and CXCL1 (GROα)] in promoting tumor cell remodeling. These inflammatory components form a common thread that is involved in regulation of the three plasticity levels: stemness/EMT, therapy resistance, and dormancy. In view of the fact that inflammatory elements are a common denominator shared by different aspects of tumor cell plasticity, it is possible that their targeting may have a critical clinical benefit for cancer patients.