Fusobacterium nucleatum promotes colorectal cancer metastasis through miR-1322/CCL20 axis and M2 polarization

Fusobacterium nucleatum in tumors: from tumorigenesis to tumor metastasis and tumor resistance

Fusobacterium nucleatum, an anaerobic Gram-negative bacterium primarily residing in the oral cavity, has garnered significant attention for its emerging role in cancer progression and prognosis. While extensive research has revealed mechanistic links between Fusobacterium nucleatum and colorectal cancer, a comprehensive review spanning its presence and metastatic implications in cancers beyond colorectal origin is conspicuously absent. This paper broadens our perspective from colorectal cancer to various malignancies associated with Fusobacterium nucleatum, including oral, pancreatic, esophageal, breast, and gastric cancers. Our central focus is to unravel the mechanisms governing Fusobacterium nucleatum colonization, initiation, and promotion of metastasis across diverse cancer types. Additionally, we explore Fusobacterium nucleatum's adverse impacts on cancer therapies, particularly within the domains of immunotherapy and chemotherapy. Furthermore, this paper underscores the clinical research significance of Fusobacterium nucleatum as a potential tumor biomarker and therapeutic target, offering a novel outlook on its applicability in cancer detection and prognostic assessment.

The role of Fusobacterium nucleatum in cancer and its implications for clinical applications

Fusobacterium nucleatum, a gram-negative anaerobic bacterium abundantly found in the human oral cavity, is widely recognized as a key pathobiont responsible for the initiation and progression of periodontal diseases due to its remarkable aggregative capabilities. Numerous clinical studies have linked F. nucleatum with unfavorable prognostic outcomes in various malignancies. In further research, scholars have partially elucidated the mechanisms underlying F. nucleatum's impact on various types of cancer, thus gaining a certain comprehension of the role played by F. nucleatum in cancer. In this comprehensive review, we present an in-depth synthesis of the interplay between F. nucleatum and different cancers, focusing on aspects such as tumor initiation, metastasis, chemoresistance, and modulation of the tumor immune microenvironment and immunotherapy. The implications for cancer diagnosis and treatment are also summarized. The objective of this review is to enhance our comprehension of the intricate relationship between F. nucleatum and oncogenic pathogenesis, while emphasizing potential therapeutic strategies.

Fusobacterium nucleatum-infected periodontitis promotes renal interstitial fibrosis in rats through the TGF-β/SMAD2/3 and β-catenin signaling pathways

OBJECTIVES

Periodontitis is associated with Fusobacterium nucleatum (F.n) infection. Although the colonization of renal tissue by F.n is well documented, its specific role in kidney disease has yet to be determined. This study aimed to investigate the potential association between F.n-induced periodontitis and renal interstitial fibrosis.

METHODS

The rat gingival sulcus was injected with F.n suspension, while the control group (NC) was injected with PBS. The levels of total protein (TP), albumin (ALB), creatinine, and urea nitrogen (BUN) in rat serum and/or urine were quantified using the appropriate kits. Renal interstitial fibrosis and epithelial-mesenchymal transition (EMT) were evaluated in rats using Masson staining, Periodic Schiff-Methenamine (PASM) staining, and immunohistochemical staining. The levels of fibrosis- and EMT-related proteins and the TGF-β/SMAD2/3 and β-catenin signaling pathways were determined using Western blot analysis. F.n in the kidney tissues was quantitatively determined using bacterial 16S rRNA technology.

RESULTS

Serum levels of TP, ALB, creatinine, and BUN were not significantly decreased in F.n-infected rats with periodontitis. The levels of creatinine and ALB in the urine were not statistically different between two groups. Masson and PASM staining showed that F.n-induced periodontitis could promote renal interstitial fibrosis in rats. The levels of collagen I, fibronectin (FN), vimentin, and α-SMA were upregulated in the kidney tissues of rats with F.n-induced periodontitis and in F.n-treated HK-2 cells. However, E-cadherin levels were reduced. F.n promoted renal interstitial and HK-2 cell fibrosis in rats by modulating the TGF-β/SMAD2/3 and β-catenin signaling pathways. F.n colonization increased renal interstitial fibrosis in rats.

CONCLUSION

F.n-induced periodontitis promoted EMT by activating the TGF-β/SMAD2/3 and β-catenin signaling pathways, thus promoting renal interstitial fibrosis in rats.

The oncomicrobiome: New insights into microorganisms in cancer

The discoveries of the oncomicrobiome (intratumoral microbiome) and oncomicrobiota (intratumoral microbiota) represent significant advances in tumor research and have rapidly become of key interest to the field. Within tumors, microorganisms such as bacteria, fungi, viruses, and archaea form the oncomicrobiota and are primarily found within tumor cells, immunocytes, and the intercellular matrix. The oncomicrobiome exhibits marked heterogeneity and is associated with tumor initiation, progression, metastasis, and treatment response. Interactions between the oncomicrobiome and the immune system can modulate host antitumor immunity, influencing the efficacy of immunotherapies. Oncomicrobiome research also faces numerous challenges, including overcoming methodological issues such as low target abundance, susceptibility to contamination, and biases in sample handling and analysis methods across different studies. Furthermore, studies of the oncomicrobiome may be confounded by baseline differences in microbiomes among populations driven by both environmental and genetic factors. Most studies to date have revealed associations between the oncomicrobiome and tumors, but very few have established mechanistic links between the two. This review introduces the relevant concepts, detection methods, sources, and characteristics of the oncomicrobiome. We then describe the composition of the oncomicrobiome in common tumors and its role in shaping the tumor microenvironment. We also discuss the current problems and challenges to be overcome in this rapidly progressing field.

Intratumoral microbiota: a new force in the development and treatment of esophageal cancer

Esophageal cancer (EC) ranks among the most prevalent cancers worldwide, with a particularly high incidence in the Asian population. Due to the inconspicuous nature of early symptoms, patients with esophageal cancer are typically diagnosed in the middle to late stages, resulting in suboptimal overall treatment outcomes. Consequently, there is an urgent need to explore and refine therapeutic strategies. Microorganisms have been identified in numerous tumor tissues, including EC, and these microorganisms are referred to as the intratumoral microbiome. Intratumoral microbiota and their metabolic byproducts can influence the progression and treatment of esophageal cancer through various mechanisms, such as modulating tumor cell metabolism and local immune responses. Therefore, the intratumoral microbiota may potentially serve as a target for the treatment of esophageal cancer. This review delineates the composition, origin, and diagnostic significance of intratumoral microbiota in esophageal cancer tissue, and discusses the mechanisms by which intratumoral microbiota contribute to the onset of esophageal cancer. In addition, the impact of intratumoral microbiota on the treatment of esophageal cancer and its intervention measures are also addressed.

Fecal microbiota transplantation alters the proteomic landscape of inflammation in HIV: identifying bacterial drivers

BACKGROUND

Despite effective antiretroviral therapy, people with HIV (PWH) experience persistent systemic inflammation and increased morbidity and mortality. Modulating the gut microbiome through fecal microbiota transplantation (FMT) represents a novel therapeutic strategy. We aimed to evaluate proteomic changes in inflammatory pathways following repeated, low-dose FMT versus placebo.

METHODS

This double-masked, placebo-controlled pilot study assessed the proteomic impacts of weekly FMT versus placebo treatment over 8 weeks on systemic inflammation in 29 PWH receiving stable antiretroviral therapy (ART). Three stool donors with high Faecalibacterium and butyrate profiles were selected, and their individual stools were used for FMT capsule preparation. Proteomic changes in 345 inflammatory proteins in plasma were quantified using the proximity extension assay, with samples collected at baseline and at weeks 1, 8, and 24. Concurrently, we characterized shifts in the gut microbiota composition and annotated functions through shotgun metagenomics. We fitted generalized additive models to evaluate the dynamics of protein expression. We selected the most relevant proteins to explore their correlations with microbiome composition and functionality over time using linear mixed models.

RESULTS

FMT significantly reduced the plasma levels of 45 inflammatory proteins, including established mortality predictors such as IL6 and TNF-α. We found notable reductions persisting up to 16 weeks after the final FMT procedure, including in the expression of proteins such as CCL20 and CD22. We identified changes in 46 proteins, including decreases in FT3LG, IL6, IL10RB, IL12B, and IL17A, which correlated with multiple bacterial species. We found that specific bacterial species within the Ruminococcaceae, Succinivibrionaceae, Prevotellaceae families, and the Clostridium genus, in addition to their associated genes and functions, were significantly correlated with changes in inflammatory markers.

CONCLUSIONS

Targeting the gut microbiome through FMT effectively decreased inflammatory proteins in PWH, with sustained effects. These findings suggest the potential of the microbiome as a therapeutic target to mitigate inflammation-related complications in this population, encouraging further research and development of microbiome-based interventions. Video Abstract.

Impact of chronic stress on intestinal mucosal immunity in colorectal cancer progression

Chronic stress is a significant risk factor that contributes to the progression of colorectal cancer (CRC) and has garnered considerable attention in recent research. It influences the distribution and function of immune cells within the intestinal mucosa through the "brain-gut" axis, altering cytokine and chemokine secretion and creating an immunosuppressive tumor microenvironment. The intestine, often called the "second brain," is particularly susceptible to the effects of chronic stress. Cytokines and chemokines in intestinal mucosal immunity（IMI） are closely linked to CRC cells' proliferation, metastasis, and drug resistance under chronic stress. Recently, antidepressants have emerged as potential therapeutic agents for CRC, possibly by modulating IMI to restore homeostasis and exert anti-tumor effects. This article reviews the role of chronic stress in promoting CRC progression via its impact on intestinal mucosal immunity, explores potential targets within the intestinal mucosa under chronic stress, and proposes new approaches for CRC treatment.

IL-17RA/CTSK axis mediates H. pylori-induced castration-resistant prostate cancer growth

In this investigation, we explored the molecular dynamics guiding the progression of castration-resistant prostate cancer (CRPC) influenced by Helicobacter pylori (H. pylori)-mediated M2 polarization of macrophages through the IL-17RA/CTSK/EMT axis. An 830-patient clinical trial categorized subjects into hormone-sensitive prostate cancer (HSPC) and CRPC groups. H. pylori infection, evaluated by ELISA, exhibited a higher incidence in CRPC patients, impacting overall survival (OS) and progression-free survival. In-depth in vitro and in vivo experiments, including 16S rDNA sequencing, immunohistochemical tests, and transcriptome analysis, unveiled that H. pylori promotes CRPC growth and metastasis by upregulating IL-17RA and CTSK, leading to enhanced EMT. Notably, M2 macrophages emerged as pivotal immune cells influencing CRPC progression. This study uncovers a novel pathway wherein H. pylori enrichment exacerbates CRPC by inducing macrophage M2 polarization, IL-17RA/CTSK expression, and EMT activation, shedding light on a previously unrecognized mechanism contributing to the growth and metastasis of CRPC.

Influence of the gut microbiota on immune cell interactions and cancer treatment

The tumour microenvironment represents a novel frontier in oncological research. Over the past decade, accumulating evidence has underscored the importance of the tumour microenvironment (TME), including tumour cells, stromal cells, immune cells, and various secreted factors, which collectively influence tumour growth, invasion, and responses to therapeutic agents. Immune cells within the TME are now widely acknowledged to play pivotal roles in tumour development and treatment. While some perspectives have posited that immune cells within the TME facilitate tumour progression and confer resistance to therapeutic interventions, contrasting conclusions also exist. Affirmative and negative conclusions appear to be context dependent, and a unified consensus has yet to be reached. The burgeoning body of research on the relationship between the gut microbiota and tumours in recent years has led to a growing understanding. Most studies have indicated that specific components of the gut microbiota, such as unique bacterial communities or specific secretory factors, play diverse roles in regulating immune cells within the TME, thereby influencing the prognosis and outcomes of cancer treatments. A detailed understanding of these factors could provide novel insights into the TME and cancer therapy. In this study, we aimed to synthesise information on the interactions between the gut microbiota and immune cells within the TME, providing an in-depth exploration of the potential guiding implications for future cancer therapies.

Gut bacteria, host immunity, and colorectal cancer: From pathogenesis to therapy

The emergence of 16S rRNA and metagenomic sequencing has gradually revealed the close relationship between dysbiosis and colorectal cancer (CRC). Recent studies have confirmed that intestinal dysbiosis plays various roles in the occurrence, development, and therapeutic response of CRC. Perturbation of host immunity is one of the key mechanisms involved. The intestinal microbiota, or specific bacteria and their metabolites, can modulate the progression of CRC through pathogen recognition receptor signaling or via the recruitment, polarization, and activation of both innate and adaptive immune cells to reshape the protumor/antitumor microenvironment. Therefore, the administration of gut bacteria to enhance immune homeostasis represents a new strategy for the treatment of CRC. In this review, we cover recent studies that illuminate the role of gut bacteria in the progression and treatment of CRC through orchestrating the immune response, which potentially offers insights for subsequent transformative research.

Single-cell RNA sequencing analysis reveals the distinct features of colorectal cancer with or without Fusobacterium nucleatum infection in PD-L1 blockade therapy

MSS/pMMR patients are unresponsive to PD-1/PD-L1 blockade in colorectal cancer (CRC), but the mechanisms are unclear. A better understanding of immunotherapy resistance in CRC may lead to more precise treatment and expand the benefit of immunotherapy to patients. In this study, we constructed mouse model of subcutaneous CRC tumor received anti-PD-L1 treatment with or without fusobacterium nucleatum (F. nucleatum) infection. Then we used single-cell RNA sequencing (scRNA-seq) to explore the comprehensive landscape of the tumor microenvironment (TME). Our data delineated the composition, subclonal diversity and putative function of distinct cells, tracked the developmental trajectory of tumor cells and highlighted cell-cell interactions. We found different compositions and functions of both tumor cells and immune cells. Single anti-PD-L1 monoclonal antibody (mAb) treated tumor exhibited two specific clusters which might be resistant to PD-L1 blockade. The accumulation of immune cells, including T cell, NK cell and pro-inflammatory macrophage subset in tumors infected with F. nucleatum may be one of the reasons for the increased sensitivity to PD-L1 blockade. Thus, targeting F. nucleatum to change the composition of tumor cell subclusters and enliven the immune response might help to overcome immune checkpoint blockade (ICB) resistance.

The MCIB Model: A Novel Theory for Describing the Spatial Heterogeneity of the Tumor Microenvironment

The tumor microenvironment (TME) can be regarded as a complex and dynamic microecosystem generated by the interactions of tumor cells, interstitial cells, the extracellular matrix, and their products and plays an important role in the occurrence, progression and metastasis of tumors. In a previous study, we constructed an IEO model (prI-, prE-, and pOst-metastatic niche) according to the chronological sequence of TME development. In this paper, to fill the theoretical gap in spatial heterogeneity in the TME, we defined an MCIB model (Metabolic, Circulatory, Immune, and microBial microenvironment). The MCIB model divides the TME into four subtypes that interact with each other in terms of mechanism, corresponding to the four major links of metabolic reprogramming, vascular remodeling, immune response, and microbial action, providing a new way to assess the TME. The combination of the MCIB model and IEO model comprehensively depicts the spatiotemporal evolution of the TME and can provide a theoretical basis for the combination of clinical targeted therapy, immunotherapy, and other comprehensive treatment modalities for tumors according to the combination and crosstalk of different subtypes in the MCIB model and provide a powerful research paradigm for tumor drug-resistance mechanisms and tumor biological behavior.

Tumor microenvironment as a complex milieu driving cancer progression: a mini review

It has been spotlighted that the Tumor Microenvironment (TME) is crucial for comprehending cancer progression and therapeutic resistance. Therefore, this comprehensive review elucidates the intricate architecture of the TME, which encompasses tumor cells, immune components, support cells, and a myriad of bioactive molecules. These constituents collectively foster dynamic interactions that underpin tumor growth, metastasis, and nuanced responses to anticancer therapies. Notably, the TME's role extends beyond mere physical support, serving as a critical mediator in cancer-cell evolution, immune modulation, and treatment outcomes. Innovations targeting the TME, including strategies focused on the vasculature, immune checkpoints, and T-cell therapies, have forged new pathways for clinical intervention. However, the heterogeneity and complexity of the TME present significant challenges, necessitating deeper exploration of its components and their interplay to enhance therapeutic efficacy. This review underscores the imperative for integrated research strategies that amalgamate insights from tumor biology, immunology, and systems biology. Such an approach aims to refine cancer treatments and improve patient prognoses by exploiting the TME's complexity.

Effects of intratumoral microbiota on tumorigenesis, anti-tumor immunity, and microbe-based cancer therapy

Intratumoral microbiota (IM) has emerged as a significant component of the previously thought sterile tumor microenvironment (TME), exerting diverse functions in tumorigenesis and immune modulation. This review outlines the historical background, classification, and diversity of IM, elucidating its pivotal roles in oncogenicity, cancer development, and progression, alongside its influence on anti-tumor immunity. The signaling pathways through which IM impacts tumorigenesis and immunity, including reactive oxygen species (ROS), β-catenin, stimulator of interferon genes (STING), and other pathways [NF-κB, Toll-like receptor (TLR), complement, RhoA/ROCK, PKR-like ER kinase (PERK)], are discussed comprehensively. Furthermore, we briefly introduce the clinical implications of IM, emphasizing its potential as a target for novel cancer therapies, diagnostic biomarkers, and prognostic indicators. Notably, microbe-based therapeutic strategies such as fecal microbiome transplantation (FMT), probiotics regulation, bacteriotherapy, bacteriophage therapy, and oncolytic virotherapy are highlighted. These strategies hold promise for enhancing the efficacy of current cancer treatments and warrant further exploration in clinical settings.

Fusobacterium nucleatum extracellular vesicles are enriched in colorectal cancer and facilitate bacterial adhesion

Fusobacterium nucleatum in colorectal cancer (CRC) tissue is implicated at multiple stages of the disease, while the mechanisms underlying bacterial translocation and colonization remain incompletely understood. Herein, we investigated whether extracellular vesicles derived from F. nucleatum (FnEVs) have impacts on bacterial colonization. In mice with colitis-related CRC, a notable enrichment of FnEVs was observed, leading to a significant increase in intratumor colonization by F. nucleatum and accelerated progression of CRC. The enrichment of FnEVs in clinical CRC tissues was demonstrated. Subsequently, we revealed that FnEVs undergo membrane fusion with CRC cells, leading to the transfer and retention of FomA on recipient cell surfaces. Given its ability to facilitate F. nucleatum autoaggregation through interaction with FN1441, the presence of FomA on CRC cell surfaces presents a target for bacterial adhesion. Collectively, the findings unveil a mechanism used by EVs to prepare a niche conducive for bacterial colonization in distal organs.

The Zeb1-Cxcl1 axis impairs the antitumor immune response by inducing M2 macrophage polarization in breast cancer

Zeb1, a key epithelial-mesenchymal transition (EMT) regulator, has recently been found to be involved in M2 macrophage polarization in the tumor immune microenvironment, thereby promoting tumor development. However, the underlying mechanism of Zeb1-induced M2 macrophage polarization remains largely unexplored. To identify the potential role of Zeb1 in remodeling the tumor immune microenvironment in breast cancer, we crossed the floxed Zeb1 allele homozygously into PyMT mice to generate PyMT;Zeb1cKO (MMTV-Cre;PyMT;Zeb1fl/fl ) mice. We found that the recruitment of M2-type tumor-associated macrophages (TAMs) was significantly reduced in tumors from PyMT;Zeb1cKO mice, and their tumor suppressive effects were weakened. Mechanistically, Zeb1 played a crucial role in transcriptionally promoting the production of Cxcl1 in tumor cells. In turn, Cxcl1 activated the Cxcr2-Jak-Stat3 pathway to induce M2 polarization of TAMs in a paracrine manner, which eventually led to T-cell inactivation and impaired the antitumor immune response in breast cancer. Our results collectively revealed an important role of Zeb1 in remodeling the tumor microenvironment, suggesting a novel therapeutic intervention for the treatment of advanced breast cancer.

Emerging roles of intratumor microbiota in cancer: tumorigenesis and management strategies

The intricate interplay between the host and its microbiota has garnered increasing attention in the past decade. Specifically, the emerging recognition of microorganisms within diverse cancer tissues, previously presumed sterile, has ignited a resurgence of enthusiasm and research endeavors. Four potential migratory routes have been identified as the sources of intratumoral microbial "dark matter," including direct invasion of mucosal barriers, spreading from normal adjacent tissue, hematogenous spread, and lymphatic drainage, which contribute to the highly heterogeneous features of intratumor microbiota. Importantly, multitudes of studies delineated the roles of intratumor microbiota in cancer initiation and progression, elucidating underlying mechanisms such as genetic alterations, epigenetic modifications, immune dysfunctions, activating oncogenic pathways, and inducing metastasis. With the deepening understanding of intratumoral microbial composition, novel microbiota-based strategies for early cancer diagnosis and prognostic stratification continue to emerge. Furthermore, intratumor microbiota exerts significant influence on the efficacy of cancer therapeutics, particularly immunotherapy, making it an enticing target for intervention in cancer treatment. In this review, we present a comprehensive discussion of the current understanding pertaining to the developmental history, heterogeneous profiles, underlying originations, and carcinogenic mechanisms of intratumor microbiota, and uncover its potential predictive and intervention values, as well as several inevitable challenges as a target for personalized cancer management strategies.

Potential role of the intratumoral microbiota in colorectal cancer immunotherapy

Colorectal cancer (CRC) has been one of the most common malignancies worldwide. Despite the advances in current therapies, the mortality rate of CRC remains high. Among them, immunotherapy has achieved satisfactory results in some CRC patients, however, how to expand the use of immunotherapy in CRC patients remains an urgent challenge. Surprisingly, the intratumoral microbiota has been found in multiple tumor tissues, including CRC. It has been demonstrated that the intratumoral microbiota is associated with the progression and treatment of CRC, and is able to enhance or decrease anti-tumor immune responses via different mechanisms as well as influence the immunotherapy efficacy, providing new potential therapeutic targets for CRC immunotherapy. In this review, we focus on the characteristics of the intratumoral microbiota, its roles in the genesis and development of CRC, its modulation of anti-tumor immune responses and immunotherapy, and propose potential applications of the intratumoral microbiota in CRC immunotherapy. Additionally, we propose possible directions for future research on the intratumoral microbiota related to CRC immunotherapy.

Antioxidant Role of Probiotics in Inflammation-Induced Colorectal Cancer

Colorectal cancer (CRC) continues to be a significant contributor to global morbidity and mortality. Emerging evidence indicates that disturbances in gut microbial composition, the formation of reactive oxygen species (ROS), and the resulting inflammation can lead to DNA damage, driving the pathogenesis and progression of CRC. Notably, bacterial metabolites can either protect against or contribute to oxidative stress by modulating the activity of antioxidant enzymes and influencing signaling pathways that govern ROS-induced inflammation. Additionally, microbiota byproducts, when supplemented through probiotics, can affect tumor microenvironments to enhance treatment efficacy and selectively mediate the ROS-induced destruction of CRC cells. This review aims to discuss the mechanisms by which taxonomical shifts in gut microbiota and related metabolites such as short-chain fatty acids, secondary bile acids, and trimethylamine-N-oxide influence ROS concentrations to safeguard or promote the onset of inflammation-mediated CRC. Additionally, we focus on the role of probiotic species in modulating ROS-mediated signaling pathways that influence both oxidative status and inflammation, such as Nrf2-Keap1, NF-κB, and NLRP3 to mitigate carcinogenesis. Overall, a deeper understanding of the role of gut microbiota on oxidative stress may aid in delaying or preventing the onset of CRC and offer new avenues for adjunct, CRC-specific therapeutic interventions such as cancer immunotherapy.

Targeting circ-0034880-enriched tumor extracellular vesicles to impede SPP1highCD206+ pro-tumor macrophages mediated pre-metastatic niche formation in colorectal cancer liver metastasis

BACKGROUND

Information transmission between primary tumor cells and immunocytes or stromal cells in distal organs is a critical factor in the formation of pre-metastatic niche (PMN). Understanding this mechanism is essential for developing effective therapeutic strategy against tumor metastasis. Our study aims to prove the hypothesis that circ-0034880-enriched tumor-derived extracellular vesicles (TEVs) mediate the formation of PMN and colorectal cancer liver metastasis (CRLM), and targeting circ-0034880-enriched TEVs might be an effective therapeutic strategy against PMN formation and CRLM.

METHODS

We utilized qPCR and FISH to measure circRNAs expression levels in human CRC plasma, primary CRC tissues, and liver metastatic tissues. Additionally, we employed immunofluorescence, RNA sequencing, and in vivo experiments to assess the effect mechanism of circ-0034880-enriched TEVs on PMN formation and CRC metastasis. DARTS, CETSA and computational docking modeling were applied to explore the pharmacological effects of Ginsenoside Rb1 in impeding PMN formation.

RESULTS

We found that circ-0034880 was highly enriched in plasma extracellular vesicles (EVs) derived from CRC patients and closely associated with CRLM. Functionally, circ-0034880-enriched TEVs entered the liver tissues and were absorbed by macrophages in the liver through bloodstream. Mechanically, TEVs-released circ-0034880 enhanced the activation of SPP1highCD206+ pro-tumor macrophages, reshaping the metastasis-supportive host stromal microenvironment and promoting overt metastasis. Importantly, our mechanistic findings led us to discover that the natural product Ginsenoside Rb1 impeded the activation of SPP1highCD206+ pro-tumor macrophages by reducing circ-0034880 biogenesis, thereby suppressing PMN formation and inhibiting CRLM.

CONCLUSIONS

Circ-0034880-enriched TEVs facilitate strong interaction between primary tumor cells and SPP1highCD206+ pro-tumor macrophages, promoting PMN formation and CRLM. These findings suggest the potential of using Ginsenoside Rb1 as an alternative therapeutic agent to reshape PMN formation and prevent CRLM.

Microbes in the tumor microenvironment: New additions to break the tumor immunotherapy dilemma

Immunotherapies currently used in clinical practice are unsatisfactory in terms of therapeutic response and toxic side effects, and therefore new immunotherapies need to be explored. Intratumoral microbiota (ITM) exists in the tumor environment (TME) and reacts with its components. On the one hand, ITM promotes antigen delivery to tumor cells or provides cross-antigens to promote immune cells to attack tumors. On the other hand, ITM affects the activity of immune cells and stromal cells. We also summarize the dialog pathways by which ITM crosstalks with components within the TME, particularly the interferon pathway. This interaction between ITM and TME provides new ideas for tumor immunotherapy. By analyzing the bidirectional role of ITM in TME and combining it with its experimental and clinical status, we summarized the adjuvant role of ITM in immunotherapy. We explored the potential applications of using ITM as tumor immunotherapy, such as a healthy diet, fecal transplantation, targeted ITM, antibiotics, and probiotics, to provide a new perspective on the use of ITM in tumor immunotherapy.

The intratumoral microbiota: a new horizon in cancer immunology

Over the past decade, advancements in high-throughput sequencing technologies have led to a qualitative leap in our understanding of the role of the microbiota in human diseases, particularly in oncology. Despite the low biomass of the intratumoral microbiota, it remains a crucial component of the tumor immune microenvironment, displaying significant heterogeneity across different tumor tissues and individual patients. Although immunotherapy has emerged a major strategy for treating tumors, patient responses to these treatments vary widely. Increasing evidence suggests that interactions between the intratumoral microbiota and the immune system can modulate host tumor immune responses, thereby influencing the effectiveness of immunotherapy. Therefore, it is critical to gain a deep understanding of how the intratumoral microbiota shapes and regulates the tumor immune microenvironment. Here, we summarize the latest advancements on the role of the intratumoral microbiota in cancer immunity, exploring the potential mechanisms through which immune functions are influenced by intratumoral microbiota within and outside the gut barrier. We also discuss the impact of the intratumoral microbiota on the response to cancer immunotherapy and its clinical applications, highlighting future research directions and challenges in this field. We anticipate that the valuable insights into the interactions between cancer immunity and the intratumoral microbiota provided in this review will foster the development of microbiota-based tumor therapies.

Research progress on the correlation between intestinal flora and colorectal cancer

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies in the world. With the rapid pace of life and changes in diet structure, the incidence and mortality of CRC increase year by year posing a serious threat to human health. As the most complex and largest microecosystem in the human body, intestinal microecology is closely related to CRC. It is an important factor that affects and participates in the occurrence and development of CRC. Advances in next-generation sequencing technology and metagenomics have provided new insights into the ecology of gut microbes. It also helps to link intestinal flora with CRC, and the relationship between intestinal flora and CRC can be continuously understood from different levels. This paper summarizes the relationship between intestinal flora and CRC and its potential role in the diagnosis of CRC providing evidence for early screening and treatment of CRC.

Peptides for microbe-induced cancers: latest therapeutic strategies and their advanced technologies

Cancer is a significant global health concern associated with multiple distinct factors, including microbial and viral infections. Numerous studies have elucidated the role of microorganisms, such as Helicobacter pylori (H. pylori), as well as viruses for example human papillomavirus (HPV), hepatitis B virus (HBV), and hepatitis C virus (HCV), in the development of human malignancies. Substantial attention has been focused on the treatment of these microorganism- and virus-associated cancers, with promising outcomes observed in studies employing peptide-based therapies. The current paper provides an overview of microbe- and virus-induced cancers and their underlying molecular mechanisms. We discuss an assortment of peptide-based therapies which are currently being developed, including tumor-targeting peptides and microbial/viral peptide-based vaccines. We describe the major technological advancements that have been made in the design, screening, and delivery of peptides as anticancer agents. The primary focus of the current review is to provide insight into the latest research and development in this field and to provide a realistic glimpse into the future of peptide-based therapies for microbe- and virus-induced neoplasms.

Multi-Omics analysis elucidates tumor microenvironment and intratumor microbes of angiogenesis subtypes in colon cancer

BACKGROUND

Angiogenesis plays an important role in colon cancer (CC) progression.

AIM

To investigate the tumor microenvironment (TME) and intratumor microbes of angiogenesis subtypes (AGSs) and explore potential targets for antiangiogenic therapy in CC.

METHODS

The data were obtained from The Cancer Genome Atlas database and Gene Expression Omnibus database. K-means clustering was used to construct the AGSs. The prognostic model was constructed based on the differential genes between two subtypes. Single-cell analysis was used to analyze the expression level of SLC2A3 on different cells in CC, which was validated by immunofluorescence. Its biological functions were further explored in HUVECs.

RESULTS

CC samples were grouped into two AGSs (AGS-A and AGS-B) groups and patients in the AGS-B group had poor prognosis. Further analysis revealed that the AGS-B group had high infiltration of TME immune cells, but also exhibited high immune escape. The intratumor microbes were also different between the two subtypes. A convenient 6-gene angiogenesis-related signature (ARS), was established to identify AGSs and predict the prognosis in CC patients. SLC2A3 was selected as the representative gene of ARS, which was higher expressed in endothelial cells and promoted the migration of HUVECs.

CONCLUSION

Our study identified two AGSs with distinct prognoses, TME, and intratumor microbial compositions, which could provide potential explanations for the impact on the prognosis of CC. The reliable ARS model was further constructed, which could guide the personalized treatment. The SLC2A3 might be a potential target for antiangiogenic therapy.

Spotlight on pro-inflammatory chemokines: regulators of cellular communication in cognitive impairment

Cognitive impairment is a decline in people's ability to think, learn, and remember, and so forth. Cognitive impairment is a global health challenge that affects the quality of life of thousands of people. The condition covers a wide range from mild cognitive impairment to severe dementia, which includes Alzheimer's disease (AD) and Parkinson's disease (PD), among others. While the etiology of cognitive impairment is diverse, the role of chemokines is increasingly evident, especially in the presence of chronic inflammation and neuroinflammation. Although inflammatory chemokines have been linked to cognitive impairment, cognitive impairment is usually multifactorial. Researchers are exploring the role of chemokines and other inflammatory mediators in cognitive dysfunction and trying to develop therapeutic strategies to mitigate their effects. The pathogenesis of cognitive disorders is very complex, their underlying causative mechanisms have not been clarified, and their treatment is always one of the challenges in the field of medicine. Therefore, exploring its pathogenesis and treatment has important socioeconomic value. Chemokines are a growing family of structurally and functionally related small (8-10 kDa) proteins, and there is growing evidence that pro-inflammatory chemokines are associated with many neurobiological processes that may be relevant to neurological disorders beyond their classical chemotactic function and play a crucial role in the pathogenesis and progression of cognitive disorders. In this paper, we review the roles and regulatory mechanisms of pro-inflammatory chemokines (CCL2, CCL3, CCL4, CCL5, CCL11, CCL20, and CXCL8) in cognitive impairment. We also discuss the intrinsic relationship between the two, hoping to provide some valuable references for the treatment of cognitive impairment.

Exploring the immune landscape and drug prediction of an M2 tumor-associated macrophage-related gene signature in EGFR-negative lung adenocarcinoma

BACKGROUND

Improving immunotherapy efficacy for EGFR-negative lung adenocarcinoma (LUAD) patients remains a critical challenge, and the therapeutic effect of immunotherapy is largely determined by the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are the top-ranked immune infiltrating cells in the TME, and M2-TAMs exert potent roles in tumor promotion and chemotherapy resistance. An M2-TAM-based prognostic signature was constructed by integrative analysis of single-cell RNA-seq (scRNA-seq) and bulk RNA-seq data to reveal the immune landscape and select drugs in EGFR-negative LUAD.

METHODS

M2-TAM-based biomarkers were obtained from the intersection of bulk RNA-seq data and scRNA-seq data. After consensus clustering of EGFR-negative LUAD into different clusters based on M2-TAM-based genes, we compared the prognosis, clinical features, estimate scores, immune infiltration, and checkpoint genes among the clusters. Next, we combined univariate Cox and LASSO regression analyses to establish an M2-TAM-based prognostic signature.

RESULTS

CCL20, HLA-DMA, HLA-DRB5, KLF4, and TMSB4X were verified as prognostic M2-like TAM-related genes by univariate Cox and LASSO regression analyses. IPS and TMB analyses revealed that the high-risk group responded better to common immunotherapy.

CONCLUSION

The study shows the potential of the M2-like TAM-related gene signature in EGFR-negative LUAD, explores the immune landscape based on M2-like TAM-related genes, and predict immunotherapy response of patients with EGFR-negative LUAD, providing a new insight for individualized treatment.

Prebiotic fibre mixtures counteract the manifestation of gut microbial dysbiosis induced by the chemotherapeutic 5-Fluorouracil (5-FU) in a validated in vitro model of the colon

BACKGROUND

5-Fluorouracil (5-FU) is used as an antineoplastic agent in distinct cancer types. Increasing evidence suggests that the gut microbiota might modulate 5-FU efficacy and toxicity, potentially affecting the patient's prognosis. The current experimental study investigated 5-FU-induced microbiota alterations, as well as the potential of prebiotic fibre mixtures (M1-M4) to counteract these shifts.

METHODS

A pooled microbial consortium was derived from ten healthy donors, inoculated in an in vitro model of the colon, and treated with 5-FU, with or without prebiotic fibre mixtures for 72 h. Four different prebiotic fibre mixtures were tested: M1 containing short-chain galacto-oligosaccharides (sc GOS), long-chain fructo-oligosaccharides (lcFOS), and low viscosity pectin (lvPect), M2 consisting of arabinoxylan, beta-glucan, pectin, and resistant starch, M3 which was a mixture of scGOS and lcFOS, and M4 containing arabinoxylan, beta-glucan, pectin, resistant starch, and inulin.

RESULTS

We identified 5-FU-induced changes in gut microbiota composition, but not in microbial diversity. Administration of prebiotic fibre mixtures during 5-FU influenced gut microbiota composition and taxa abundance. Amongst others, prebiotic fibre mixtures successfully stimulated potentially beneficial bacteria (Bifidobacterium, Lactobacillus, Anaerostipes, Weissella, Olsenella, Senegalimassilia) and suppressed the growth of potentially pathogenic bacteria (Klebsiella, Enterobacter) in the presence of 5-FU. The short-chain fatty acid (SCFA) acetate increased slightly during 5-FU, but even more during 5-FU with prebiotic fibre mixtures, while propionate was lower due to 5-FU with or without prebiotic fibre mixtures, compared to control. The SCFA butyrate and valerate did not show differences among all conditions. The branched-chain fatty acids (BCFA) iso-butyrate and iso-valerate were higher in 5-FU, but lower in 5-FU + prebiotics, compared to control.

CONCLUSIONS

These data suggest that prebiotic fibre mixtures represent a promising strategy to modulate 5-FU-induced microbial dysbiosis towards a more favourable microbiota, thereby possibly improving 5-FU efficacy and reducing toxicity, which should be evaluated further in clinical studies.

Application of Fusobacterium nucleatum as a biomarker in gastrointestinal malignancies

The morbidity and mortality of gastrointestinal (GI) malignancies are among the highest in the world, posing a serious threat to human health. Because of the insidious onset of the cancer, it is difficult for patients to be diagnosed at an early stage, and it rapidly progresses to an advanced stage, resulting in poor treatment and prognosis. Fusobacterium nucleatum (F. nucleatum) is a gram-negative, spore-free anaerobic bacterium that primarily colonizes the oral cavity and is implicated in the development of colorectal, esophageal, gastric, and pancreatic cancers via various intricate mechanisms. Recent development in novel research suggests that F. nucleatum may function as a biomarker in GI malignancies. Detecting the abundance of F. nucleatum in stool, saliva, and serum samples of patients may aid in the diagnosis, risk assessment, and prognosis monitoring of GI malignancies. This editorial systematically describes the biological roles and mechanisms of F. nucleatum in GI malignancies focusing on the application of F. nucleatum as a biomarker in the diagnosis and prognosis of GI malignancies to promote the clinical translation of F. nucleatum and GI tumors-related research.

Microbiome-driven anticancer therapy: A step forward from natural products

Human microbiomes, considered as a new emerging and enabling cancer hallmark, are increasingly recognized as critical effectors in cancer development and progression. Manipulation of microbiome revitalizing anticancer therapy from natural products shows promise toward improving cancer outcomes. Herein, we summarize our current understanding of the human microbiome-driven molecular mechanisms impacting cancer progression and anticancer therapy. We highlight the potential translational and clinical implications of natural products for cancer prevention and treatment by developing targeted therapeutic strategies as adjuvants for chemotherapy and immunotherapy against tumorigenesis. The challenges and opportunities for future investigations using modulation of the microbiome for cancer treatment are further discussed in this review.

Fusobacteria alterations are associated with colorectal cancer liver metastasis and a poor prognosis

Liver metastasis is a major cause of mortality in patients with advanced stages of colorectal cancer (CRC). The gut microbiota has been demonstrated to influence the progression of liver diseases, potentially providing novel perspectives for diagnosis, treatment and research. However, the gut microbial characteristics in CRC with liver metastasis (LM) and with no liver metastasis (NLM) have not yet been fully established. In the present study, high-throughput 16S RNA sequencing technology was employed, in order to examine the gut microbial richness and composition in patients with CRC with LM or NLM. A discovery cohort (cohort 2; LM=18; NLM=36) and a validation cohort (cohort 3; LM=13; NLM=41) were established using fresh feces. In addition, primary carcinoma tissue samples were also analyzed (LM=8 and NLM=10) as a supplementary discovery cohort (cohort 1). The findings of the present study indicated that the intestinal microbiota richness and diversity were increased in the LM group as compared to the NLM group. A significant difference was observed in species composition between the LM and NLM group. In the two discovery cohorts with two different samples, the dominant phyla were consistent, but varied at lower taxonomic levels. Phylum Fusobacteria presented consistent and significant enrichment in LM group in both discovery cohorts. Furthermore, with the application of a random forest model and receiver operator characteristic curve analysis, Fusobacteria was identified as a potential biomarker for LM. Moreover, Fusobacteria was also a poor prognosis factor for survival. Importantly, the findings were reconfirmed in the validation cohort. On the whole, the findings of the present study demonstrated that CRC with LM and NLM exhibit distinct gut microbiota characteristics. Fusobacteria detection thus has potential for use in predicting LM and a poor prognosis of patients with CRC.

Development of the ARDS-derived gene panel for lung adenocarcinoma prognosis stratification and experiment validation of CCL20 expression

Acute respiratory distress syndrome (ARDS) is a life-threatening condition characterized by lung inflammation and high mortality rates. Lung cancer, specifically lung adenocarcinoma (LUAD), is a major cause of cancer-related deaths worldwide. Patients with LUAD, particularly those undergoing chemotherapy, are more likely to develop ARDS. ARDS inflicts major malfunctioning in the immune system. We suspected a certain shared pathogenic mechanism between these diseases. This study analyzed 503 LUAD patients from the TCGA-LUAD cohort as the training set, 85 LUAD cases from the GSE30219 cohort as the validation set, and 24 RNA-seq samples from ARDS mice model and control groups in the GSE2411 cohort. The differentially expressed genes (DEGs) of ARDS were analyzed using the limma package and screened by Cox and Lasso analysis. ssGSEA and xCell algorithms were utilized for immune landscaping. RT-qPCR analysis was used to determine the mRNA levels of key genes in both the LPS-induced ARDS model and human LUAD cell lines. We identified DEGs between ARDS and control groups, which were highly associated with cytokine production and leukocyte migration. A prognosis model for LUAD patients was developed based on the expressions of the key genes in the ARDS-derived DEGs, including FMO3, IL1R2, CCL20, CFTR, and GADD45G. A satisfactory efficacy was observed in both the training and validation cohorts. The model demonstrated increased effectiveness in predicting the intratumor immune profile and mutation status of LUAD. Moreover, we utilized LPS to induce the ARDS model, which resulted in elevated expressions of IL1R2 and CCL20. Additionally, CCL20 was upregulated in cancerous LUAD cell lines. We developed an ARDS-based model for stratifying LUAD prognosis. CCL20 was found to be elevated in both the ARDS model and LUAD, suggesting a shared underlying mechanism of these two diseases.

The interactions between traditional Chinese medicine and gut microbiota in cancers: Current status and future perspectives

The gut microbiota, known as the "forgotten organ" and "human second genome," comprises a complex microecosystem. It significantly influences the development of various tumors, including colorectal, liver, stomach, breast, and lung cancers, through both direct and indirect mechanisms. These mechanisms include the "gut-liver" axis, the "lung-intestine" axis, and interactions with the immune system. The intestinal flora exhibits dual roles in cancer, both promoting and suppressing its progression. Traditional Chinese medicine (TCM) can alter cancer progression by regulating the intestinal flora. It modifies the intestinal flora's composition and structure, along with the levels of endogenous metabolites, thus affecting the intestinal barrier, immune system, and overall body metabolism. These actions contribute to TCM's significant antitumor effects. Moreover, the gut microbiota metabolizes TCM components, enhancing their antitumor properties. Therefore, exploring the interaction between TCM and the intestinal flora offers a novel perspective in understanding TCM's antitumor mechanisms. This paper succinctly reviews the association between gut flora and the development of tumors, including colorectal, liver, gastric, breast, and lung cancers. It further examines current research on the interaction between TCM and intestinal flora, with a focus on its antitumor efficacy. It identifies limitations in existing studies and suggests recommendations, providing insights into antitumor drug research and exploring TCM's antitumor effectiveness. Additionally, this paper aims to guide future research on TCM and the gut microbiota in antitumor studies.

The multispecies microbial cluster of Fusobacterium, Parvimonas, Bacteroides and Faecalibacterium as a precision biomarker for colorectal cancer diagnosis

The incidence of colorectal cancer (CRC) has increased worldwide, and early diagnosis is crucial to reduce mortality rates. Therefore, new noninvasive biomarkers for CRC are required. Recent studies have revealed an imbalance in the oral and gut microbiomes of patients with CRC, as well as impaired gut vascular barrier function. In the present study, the microbiomes of saliva, crevicular fluid, feces, and non-neoplastic and tumor intestinal tissue samples of 93 CRC patients and 30 healthy individuals without digestive disorders (non-CRC) were analyzed by 16S rRNA metabarcoding procedures. The data revealed that Parvimonas, Fusobacterium, and Bacteroides fragilis were significantly over-represented in stool samples of CRC patients, whereas Faecalibacterium and Blautia were significantly over-abundant in the non-CRC group. Moreover, the tumor samples were enriched in well-known periodontal anaerobes, including Fusobacterium, Parvimonas, Peptostreptococcus, Porphyromonas, and Prevotella. Co-occurrence patterns of these oral microorganisms were observed in the subgingival pocket and in the tumor tissues of CRC patients, where they also correlated with other gut microbes, such as Hungatella. This study provides new evidence that oral pathobionts, normally located in subgingival pockets, can migrate to the colon and probably aggregate with aerobic bacteria, forming synergistic consortia. Furthermore, we suggest that the group composed of Fusobacterium, Parvimonas, Bacteroides, and Faecalibacterium could be used to design an excellent noninvasive fecal test for the early diagnosis of CRC. The combination of these four genera would significantly improve the reliability of a discriminatory test with respect to others that use a single species as a unique CRC biomarker.

Unveiling the gastric microbiota: implications for gastric carcinogenesis, immune responses, and clinical prospects

High-throughput sequencing has ushered in a paradigm shift in gastric microbiota, breaking the stereotype that the stomach is hostile to microorganisms beyond H. pylori. Recent attention directed toward the composition and functionality of this 'community' has shed light on its potential relevance in cancer. The microbial composition in the stomach of health displays host specificity which changes throughout a person's lifespan and is subject to both external and internal factors. Distinctive alterations in gastric microbiome signature are discernible at different stages of gastric precancerous lesions and malignancy. The robust microbes that dominate in gastric malignant tissue are intricately implicated in gastric cancer susceptibility, carcinogenesis, and the modulation of immunosurveillance and immune escape. These revelations offer fresh avenues for utilizing gastric microbiota as predictive biomarkers in clinical settings. Furthermore, inter-individual microbiota variations partially account for differential responses to cancer immunotherapy. In this review, we summarize current literature on the influence of the gastric microbiota on gastric carcinogenesis, anti-tumor immunity and immunotherapy, providing insights into potential clinical applications.

The role of CXCL2-mediated crosstalk between tumor cells and macrophages in Fusobacterium nucleatum-promoted oral squamous cell carcinoma progression

Dysbiosis of the oral microbiota is related to chronic inflammation and carcinogenesis. Fusobacterium nucleatum (Fn), a significant component of the oral microbiota, can perturb the immune system and form an inflammatory microenvironment for promoting the occurrence and progression of oral squamous cell carcinoma (OSCC). However, the underlying mechanisms remain elusive. Here, we investigated the impacts of Fn on OSCC cells and the crosstalk between OSCC cells and macrophages. 16 s rDNA sequencing and fluorescence in situ hybridization verified that Fn was notably enriched in clinical OSCC tissues compared to paracancerous tissues. The conditioned medium co-culture model validated that Fn and macrophages exhibited tumor-promoting properties by facilitating OSCC cell proliferation, migration, and invasion. Besides, Fn and OSCC cells can recruit macrophages and facilitate their M2 polarization. This crosstalk between OSCC cells and macrophages was further enhanced by Fn, thereby amplifying this positive feedback loop between them. The production of CXCL2 in response to Fn stimulation was a significant mediator. Suppression of CXCL2 in OSCC cells weakened Fn's promoting effects on OSCC cell proliferation, migration, macrophage recruitment, and M2 polarization. Conversely, knocking down CXCL2 in macrophages reversed the Fn-induced feedback effect of macrophages on the highly invasive phenotype of OSCC cells. Mechanistically, Fn activated the NF-κB pathway in both OSCC cells and macrophages, leading to the upregulation of CXCL2 expression. In addition, the SCC7 subcutaneous tumor-bearing model in C3H mice also substantiated Fn's ability to enhance tumor progression by facilitating cell proliferation, activating NF-κB signaling, up-regulating CXCL2 expression, and inducing M2 macrophage infiltration. However, these effects were reversed by the CXCL2-CXCR2 inhibitor SB225002. In summary, this study suggests that Fn contributes to OSCC progression by promoting tumor cell proliferation, macrophage recruitment, and M2 polarization. Simultaneously, the enhanced CXCL2-mediated crosstalk between OSCC cells and macrophages plays a vital role in the pro-cancer effect of Fn.

Role of imbalanced gut microbiota in promoting CRC metastasis: from theory to clinical application

Metastasis poses a major challenge in colorectal cancer (CRC) treatment and remains a primary cause of mortality among patients with CRC. Recent investigations have elucidated the involvement of disrupted gut microbiota homeostasis in various facets of CRC metastasis, exerting a pivotal influence in shaping the metastatic microenvironment, triggering epithelial-mesenchymal transition (EMT), and so on. Moreover, therapeutic interventions targeting the gut microbiota demonstrate promise in enhancing the efficacy of conventional treatments for metastatic CRC (mCRC), presenting novel avenues for mCRC clinical management. Grounded in the "seed and soil" hypothesis, this review consolidates insights into the mechanisms by which imbalanced gut microbiota promotes mCRC and highlights recent strides in leveraging gut microbiota modulation for the clinical prevention and treatment of mCRC. Emphasis is placed on the considerable potential of manipulating gut microbiota within clinical settings for managing mCRC.

VDR promotes pancreatic cancer progression in vivo by activating CCL20-mediated M2 polarization of tumor associated macrophage

BACKGROUND

Activation of VDR pathway was a promising anti-tumor therapy strategy. However, numerous clinical studies have demonstrated the effect of activating VDR is limited, which indicates that VDR plays a complex role in vivos.

METHODS

We analyzed the TCGA database to examine the association between VDR expression and immune cell infiltration in pancreatic adenocarcinoma (PAAD). Western blot, ELISA, ChIP, and dual-luciferase reporter assays were performed to determine the mechanism of VDR regulating CCL20. Migration assay and immunofluorescence were used to investigate the role of CCL20 in M2 macrophage polarization and recruitment. We employed multiplexed immunohistochemical staining and mouse models to validate the correlation of VDR on macrophages infiltration in PAAD. Flow cytometry analysis of M2/M1 ratio in subcutaneous graft tumors.

RESULTS

VDR is extensively expressed in PAAD, and patients with elevated VDR levels exhibited a significantly reduced overall survival. VDR expression in PAAD tissues was associated with increased M2 macrophages infiltration. PAAD cells overexpressing VDR promote macrophages polarization towards M2 phenotype and recruitment in vitro and vivo. Mechanistically, VDR binds to the CCL20 promoter and up-regulates its transcription. The effects of polarization and recruitment on macrophages can be rescued by blocking CCL20. Finally, the relationship between VDR and M2 macrophages infiltration was evaluated using clinical cohort and subcutaneous graft tumors. A positive correlation was demonstrated between VDR/CCL20/CD163 in PAAD tissues and mouse models.

CONCLUSION

High expression of VDR in PAAD promotes M2 macrophage polarization and recruitment through the secretion of CCL20, which activates tumor progression. This finding suggests that the combination of anti-macrophage therapy may improve the efficacy of VDR activation therapy in PAAD.

Global status and trends of gastric cancer and gastric microbiota research: a bibliometric analysis

Background

Numerous studies have cast light on the relationship between the gastric microbiota and gastric carcinogenesis. In this study, we conducted a bibliometric analysis of the relevant literature in the field of gastric cancer and the gastric microbiota and clarified its research status, hotspots, and development trends.

Materials and methods

Publications were retrieved from the Web of Science Core Collection on 18 July 2023. CiteSpace 6.2.R4, VOSviewer 1.6.19.0, and Biblioshiny were used for the co-occurrence and cooperation analyses of countries, institutions, authors, references, and keywords. A keyword cluster analysis and an emergence analysis were performed, and relevant knowledge maps were drawn.

Results

The number of published papers in this field totaled 215 and showed an increasing trend. The analysis of funding suggested that the input in this field is increasing steadily. China had the highest number of publications, while the United States had the highest betweenness centrality. Baylor College of Medicine published the most articles cumulatively. Both Ferreira RM and Cooker OO had the highest citation frequency. The journal Helicobacter showed the most interest in this field, while Gut provided a substantial research foundation. A total of 280 keywords were obtained using CiteSpace, which were primarily focused on the eradication and pathogenic mechanisms of Helicobacter pylori, as well as the application of the gastric microbiota in the evaluation and treatment of gastric cancer. The burst analysis suggested that in the future, research may focus on the application of gastric microorganisms, particularly Fusobacterium nucleatum, in the diagnosis and treatment of gastric cancer, along with their pathogenic mechanisms.

Conclusion

Current studies have been tracking the eradication of Helicobacter pylori and its pathogenic mechanisms, as well as changes in the gastric microbiota during gastric carcinogenesis. Future research may focus on the clinical application and pathogenesis of stomach microorganisms through bacteria such as Fusobacterium nucleatum.

Integrative analysis reveals associations between oral microbiota dysbiosis and host genetic and epigenetic aberrations in oral cavity squamous cell carcinoma

Dysbiosis of the human oral microbiota has been reported to be associated with oral cavity squamous cell carcinoma (OSCC) while the host-microbiota interactions with respect to the potential impact of pathogenic bacteria on host genomic and epigenomic abnormalities remain poorly studied. In this study, the mucosal bacterial community, host genome-wide transcriptome and DNA CpG methylation were simultaneously profiled in tumors and their adjacent normal tissues of OSCC patients. Significant enrichment in the relative abundance of seven bacteria species (Fusobacterium nucleatum, Treponema medium, Peptostreptococcus stomatis, Gemella morbillorum, Catonella morbi, Peptoanaerobacter yurli and Peptococcus simiae) were observed in OSCC tumor microenvironment. These tumor-enriched bacteria formed 254 positive correlations with 206 up-regulated host genes, mainly involving signaling pathways related to cell adhesion, migration and proliferation. Integrative analysis of bacteria-transcriptome and bacteria-methylation correlations identified at least 20 dysregulated host genes with inverted CpG methylation in their promoter regions associated with enrichment of bacterial pathogens, implying a potential of pathogenic bacteria to regulate gene expression, in part, through epigenetic alterations. An in vitro model further confirmed that Fusobacterium nucleatum might contribute to cellular invasion via crosstalk with E-cadherin/β-catenin signaling, TNFα/NF-κB pathway and extracellular matrix remodeling by up-regulating SNAI2 gene, a key transcription factor of epithelial-mesenchymal transition (EMT). Our work using multi-omics approaches explored complex host-microbiota interactions and provided important insights into genetic and functional basis in OSCC tumorigenesis, which may serve as a precursor for hypothesis-driven study to better understand the causational relationship of pathogenic bacteria in this deadly cancer.

Tumor-resident microbes: the new kids on the microenvironment block

Tumor-resident microbes (TRM) are an integral component of the tumor microenvironment (TME). TRM can influence tumor growth, distant dissemination, and response to therapies by interfering with molecular pathways in tumor cells as well as with other components of the TME. Novel technologies are improving the identification and visualization of cell type-specific microbes in the TME. The mechanisms that mediate the role of TRM at the primary tumors and metastatic sites are being elucidated. This knowledge is providing novel perspectives for targeting microbes or using microbial interventions for cancer interception or therapy.

Integrated Multiomics Reveals Silencing of has_circ_0006646 Promotes TRIM21-Mediated NCL Ubiquitination to Inhibit Hepatocellular Carcinoma Metastasis

Recent studies suggest that circular RNA (circRNA)-mediated post-translational modification of RNA-binding proteins (RBP) plays a pivotal role in metastasis of hepatocellular carcinoma (HCC). However, the specific mechanism and potential clinical therapeutic significance remain vague. This study attempts to profile the regulatory networks of circRNA and RBP using a multi-omics approach. Has_circ_0006646 (circ0006646) is an unreported circRNA in HCC and is associated with a poor prognosis. Silencing of circ0006646 significantly hinders metastasis in vivo. Mechanistically, circ0006646 prevents the interaction between nucleolin (NCL) and the E3 ligase tripartite motif-containing 21 to reduce the proteasome-mediated degradation of NCL via K48-linked polyubiquitylation. Furthermore, the change of NCL expression is proven to affect the phosphorylation levels of multiple proteins and inhibit p53 translation. Moreover, patient-derived tumor xenograft and lentivirus injection, which is conducted to simulate clinical treatment confirmed the potential therapeutic value. Overall, this study describes the integrated multi-omics landscape of circRNA-mediated NCL ubiquitination degradation in HCC metastasis and provides a novel therapeutic target.

Identification of macrophage-related genes correlated with prognosis and immunotherapy efficacy in non-small cell lung cancer

Background

Malignant tumours, particularly non-small cell lung cancer (NSCLC), pose a significant threat to human health due to their prevalence and lethality. Treatment methods for NSCLC vary greatly among individuals, making it crucial to identify predictive markers. Moreover, during tumour initiation and progression, tumour cells can release signaling molecules to induce polarization of macrophages towards a more tumour friendly M2 phenotype, which can promote tumour growth, metastasis, and drug resistance.

Methods

We employed a comprehensive approach, combining bulk RNA-seq and single-cell sequencing analysis.

Results

In our study, we used bulk RNA-seq and single-cell sequencing methods to analyze differential cells in NSCLC and adjacent tissues, searching for relevant marker genes that can predict prognosis and drug efficacy. We scrutinized biological phenomena such as macrophage-related gene methylation, copy number variation, and alternative splicing. Additionally, we utilized a co-culture technique of immune and tumour cells to explore the role of these genes in macrophage polarization. Our findings revealed distinct differences in macrophages between cancerous and adjacent tissues. We identified ANP32A, CCL20, ERAP2, MYD88, TMEM126B, TUBB6, and ZNF655 as macrophage-related genes that correlate with NSCLC patient prognosis and immunotherapy efficacy. Notably, ERAP2, TUBB6, CCL20, and TMEM126B can induce macrophage M0 to M2 polarization, promoting tumour proliferation.

Conclusion

These findings significantly contribute to our understanding of the NSCLC tumour immune microenvironment. They pave the way for further research into the potential of these genes as targets for regulating tumour occurrence and development.

HOXD3 promotes the migration and angiogenesis of hepatocellular carcinoma via modifying hepatocellular carcinoma cells exosome-delivered CCR6 and regulating chromatin conformation of CCL20

Angiogenesis plays an essential role in the microenvironment of hepatocellular carcinoma (HCC). HOXD3 is involved in the metastasis and invasion of HCC cells; Whereas the underlying molecular mechanisms in the microenvironment of HCC remain unknown. Wound healing, transwell invasion, tube formation and spheroid sprouting assays were carried out to identify the effects of HCC-HOXD3-exosomes and genes on the migration of HCC cells. ChIP-PCR was applied to test the binding region of HOXD3 on CCR6, Med15, and CREBBP promoter. Exosome isolation and mRNA-seq were applied to examine the morphological characteristics of exosomes and the contained mRNA in exosomes. Co-IP and Immunofluorescence assays were used to demonstrate the role of CREBBP in the chromatin conformation of CCL20. The nude mice were used to identify the function of genes in regulating migration of HCC in vivo. In this study, integrated cellular and bioinformatic analyses revealed that HOXD3 targeted the promoter region of CCR6 and induced its transcription. CCR6 was delivered by exosomes to endothelial cells and promoted tumour migration. Overexpression of CCR6 promoted metastasis, invasion in HCCs and angiogenesis in endothelial cells (ECs), whereas its downregulation suppressed these functions. The role of HOXD3 in the metastasis and invasion of HCC cells was reversed after the suppression of CCR6. Furthermore, CCL20 was demonstrated as the ligand of CCR6, and its high expression was found in HCC tissues and cells, which was clinically associated with the poor prognosis of HCC. Mechanistically, HOXD3 targets the promoter regions of CREBBP and Med15, which affect CCL20 chromatin conformation by regulating histone acetylation and expression of Pol II to enhance the migration of HCCs. This study demonstrated the function of the HOXD3-CREBBP/Med15-CCL20-CCR6 axis in regulating invasion and migration in HCC, thus providing new therapeutic targets for HCC.

The triangular relationship between traditional Chinese medicines, intestinal flora, and colorectal cancer

Over the past decade, colorectal cancer has reported a higher incidence in younger adults and a lower mortality rate. Recently, the influence of the intestinal flora in the initiation, progression, and treatment of colorectal cancer has been extensively studied, as well as their positive therapeutic impact on inflammation and the cancer microenvironment. Historically, traditional Chinese medicine (TCM) has been widely used in the treatment of colorectal cancer via promoted cancer cell apoptosis, inhibited cancer metastasis, and reduced drug resistance and side effects. The present research is more on the effect of either herbal medicine or intestinal flora on colorectal cancer. The interactions between TCM and intestinal flora are bidirectional and the combined impacts of TCM and gut microbiota in the treatment of colon cancer should not be neglected. Therefore, this review discusses the role of intestinal bacteria in the progression and treatment of colorectal cancer by inhibiting carcinogenesis, participating in therapy, and assisting in healing. Then the complex anticolon cancer effects of different kinds of TCM monomers, TCM drug pairs, and traditional Chinese prescriptions embodied in apoptosis, metastasis, immune suppression, and drug resistance are summarized separately. In addition, the interaction between TCM and intestinal flora and the combined effect on cancer treatment were analyzed. This review provides a mechanistic reference for the application of TCM and intestinal flora in the clinical treatment of colorectal cancer and paves the way for the combined development and application of microbiome and TCM.

Application of two-dimensional polymerase chain reaction to detect four types of microorganisms in feces for assisted diagnosis of IBD

BACKGROUND

The incidence of inflammatory bowel disease (IBD) continues to increase annually, accounting for about 6.8 million cases in 2017 worldwide. However, there is currently no gold standard for the diagnosis of IBD.

METHODS

A method for the detection of four microorganisms in feces by two-dimensional polymerase chain reaction (2D-PCR) has been developed. Plasmids were used to validate the sensitivity and specificity of the method. Clinical samples were tested using a 2D-PCR method. Optimal diagnostic thresholds for IBD were determined based on ROC results.

RESULTS

Of the 112 samples, 78 were from IBD patients and 34 from patients with other gastrointestinal (GI) diseases. Thomasclavelia ramosum and univ907-1062 positivity are necessary, and two or more positives of the three bacteria (Thomasclavelia spiroforme, Thomasclavelia saccharogumia or Clostridium cluster XVIII) are the optimal diagnostic thresholds for IBD. The area under the curve was 0.826 with a 95% confidence interval of 0.735-0.981 and a p-value of 0.000, corresponding to a sensitivity of 0.769 and a specificity of 0.853.

CONCLUSIONS

Based on the detection results of microorganisms, IBD and GI can be effectively distinguished. The detection of four microorganisms in feces can assist clinicians in the differential diagnosis of IBD. Our experiment aims to provide a better program for early clinical diagnosis and regular dynamic monitoring of IBD.

Integrative methylome and transcriptome analysis reveals epigenetic regulation of Fusobacterium nucleatum in laryngeal cancer

The aetiological mechanisms of Fusobacterium nucleatum in laryngeal cancer remain unclear. This study aimed to reveal the epigenetic signature induced by F. nucleatum in laryngeal squamous cell carcinoma (LSCC). Combined analysis of methylome and transcriptome data was performed to address the functional role of F. nucleatum in laryngeal cancer. Twenty-nine differentially expressed methylation-driven genes were identified by mapping the methylation levels of significant differential methylation sites to the expression levels of related genes. The combined analysis revealed that F. nucleatum promoted Janus kinase 3 (JAK3) gene expression in LSCC. Further validation found decreased methylation and elevated expression of JAK3 in the F. nucleatum-treated LSCC cell group; F. nucleatum abundance and JAK3 gene expression had a positive correlation in tumour tissues. This analysis provides a novel understanding of the impact of F. nucleatum in the methylome and transcriptome of laryngeal cancer. Identification of these epigenetic regulatory mechanisms opens up new avenues for mechanistic studies to explore novel therapeutic strategies.

Fusobacterium nucleatum outer membrane vesicles activate autophagy to promote oral cancer metastasis

INTRODUCTION

Metastasis is an important cause of high mortality and lethality of oral cancer. Fusobacterium nucleatum (Fn) can promote tumour metastasis. Outer membrane vesicles (OMVs) are secreted by Fn. However, the effects of Fn-derived extracellular vesicles on oral cancer metastasis and the underlying mechanisms are unclear.

OBJECTIVES

We aimed to determine whether and how Fn OMVs mediate oral cancer metastasis.

METHODS

OMVs were isolated from brain heart infusion (BHI) broth supernatant of Fn by ultracentrifugation. Tumour-bearing mice were treated with Fn OMVs to evaluate the effect of OMVs on cancer metastasis. Transwell assays were performed to determine how Fn OMVs affect cancer cell migration and invasion. The differentially expressed genes in Fn OMV-treated/untreated cancer cells were identified by RNA-seq. Transmission electron microscopy, laser confocal microscopy, and lentiviral transduction were used to detect changes in autophagic flux in cancer cells stimulated with Fn OMVs. Western blotting assay was performed to determine changes in EMT-related marker protein levels in cancer cells. Fn OMVs' effects on migration after blocking autophagic flux by autophagy inhibitors were determined by in vitro and in vivo experiments.

RESULTS

Fn OMVs were structurally similar to vesicles. In the in vivo experiment, Fn OMVs promoted lung metastasis in tumour-bearing mice, while chloroquine (CHQ, an autophagy inhibitor) treatment reduced the number of pulmonary metastases resulting from the intratumoral Fn OMV injection. Fn OMVs promoted the migration and invasion of cancer cells in vivo, leading to altered expression levels of EMT-related proteins (E-cadherin downregulation; Vimentin/N-cadherin upregulation). RNA-seq showed that Fn OMVs activate intracellular autophagy pathways. Blocking autophagic flux with CHQ reduced in vitro and in vivo migration of cancer cells induced by Fn OMVs as well as reversed changes in EMT-related protein expression.

CONCLUSION

Fn OMVs not only induced cancer metastasis but also activated autophagic flux. Blocking autophagic flux weakened Fn OMV-stimulated cancer metastasis.

miR-135b Aggravates Fusobacterium nucleatum-Induced Cisplatin Resistance in Colorectal Cancer by Targeting KLF13

Cisplatin resistance is the main cause of colorectal cancer (CRC) treatment failure, and the cause has been reported to be related to Fusobacterium nucleatum (Fn) infection. In this study, we explored the role of Fn in regulating cisplatin resistance of CRC cells and its underlying mechanism involved. The mRNA and protein expressions were examined by qRT-PCR and western blot. Cell proliferation and cell apoptosis were assessed using CCK8 and flow cytometry assays, respectively. Dual-luciferase reporter gene assay was adopted to analyze the molecular interactions. Herein, our results revealed that Fn abundance and miR-135b expression were markedly elevated in CRC tissues, with a favorable association between the two. Moreover, Fn infection could increase miR-135b expression via a concentration-dependent manner, and it also enhanced cell proliferation but reduced apoptosis and cisplatin sensitivity by upregulating miR-135b. Moreover, KLF13 was proved as a downstream target of miR-135b, of which overexpression greatly diminished the promoting effect of miR-135b or Fn-mediated cisplatin resistance in CRC cells. In addition, it was observed that upstream 2.5 kb fragment of miR-135b promoter could be interacted by β-catenin/TCF4 complex, which was proved as an effector signaling of Fn. LF3, a blocker of β-catenin/TCF4 complex, was confirmed to diminish the promoting role of Fn on miR-135b expression. Thus, it could be concluded that Fn activated miR-135b expression through TCF4/β-catenin complex, thereby inhibiting KLF13 expression and promoting cisplatin resistance in CRC.

Extracellular vesicles from Fusobacterium nucleatum: roles in the malignant phenotypes of gastric cancer

The increase of the Fusobacterium nucleatum level has been previously identified in various cancers including gastric cancer (GC), but how the F. nucleatum exerts its carcinogenic role in GC remains unclear. Several studies revealed that F. nucleatum contributes to cancer progression via its secretion of extracellular vehicles (EVs). Hence, it's designed to reveal the influence of F. nucleatum-derived EVs (Fn-EVs) in GC progression. The tumor and adjacent tissues were collected from 30 GC patients, and the abundance of F. nucleatum was found to be highly expressed in tumor samples. The ultracentrifugation was employed to isolate EVs from F. nucleatum and Escherischia coli (E. coli), which were labeled Fn-EVs and E. coli-EVs, respectively. After treating GC cells with Fn-EVs and E. coli-EVs, cell counting kit 8, colony formation, wound healing as well as transwell assay were performed, which revealed that Fn-EVs effectively enhanced oxaliplatin resistance, and facilitated cell proliferation, migration, invasion, and stemness in GC cells while E. coli-EVs exert no significant effect on GC cells. Besides, the stemness and DNA repair of GC cells were also enhanced by Fn-EVs, as revealed by the sphere-forming assay and the detection of stemness- and DNA repair-associated proteins by western blotting. In vivo analyses demonstrated that Fn-EVs administration not only promoted GC tumor growth and liver metastasis but also conferred GC tumor resistance to oxaliplatin resistance. This study first revealed the contributive role of F. nucleatum in GC development via Fn-EVs, which provided a better perspective for manipulating F. nucleatum in treating GC patients with malignant phenotypes.