Hypoxia and its impact on the tumour microenvironment of gastroesophageal cancers

The malfeasant role of the hypoxic tumour microenvironment(TME)in cancer progression was recognized decades ago but the exact mechanisms that augment the hallmarks of cancer and promote treatment resistance continue to be elucidated.Gastroesophageal cancers(GOCs)represent a major burden of worldwide disease,responsible for the deaths of over 1 million people annually.Disentangling the impact of hypoxia in GOCs enables a better overall understanding of the disease pathogenesis while shining a light on novel therapeutic strategies and facilitating precision treatment approaches with the ultimate goal of improving outcomes for patients with these diseases.This review discusses the underlying principles and processes of the hypoxic response and the effect of hypoxia in promoting the hallmarks of cancer in the context of GOCs.We focus on its bidirectional influence on inflammation and how it drives angiogenesis,innate and adaptive immune evasion,metastasis,and the reprogramming of cellular bioenergetics.The contribution of the hypoxic GOC TME to treatment resistance is examined and a brief overview of the pharmacodynamics of hypoxiatargeted therapeutics is given.The principal methods that are used in measuring hypoxia and how they may enhance prognostication or provide rationale for individually tailored management in the case of tumours with significant hypoxic regions are also discussed.

Recent developments in application of single-cell RNA sequencing in the tumour immune microenvironment and cancer therapy

The advent of single-cell RNA sequencing(scRNA-seq)has provided insight into the tumour immune microenvironment(TIME).This review focuses on the application of scRNA-seq in investigation of the TIME.Over time,scRNA-seq methods have evolved,and components of the TIME have been deciphered with high resolution.In this review,we first introduced the principle of scRNA-seq and compared different sequencing approaches.Novel cell types in the TIME,a continuous transitional state,and mutual intercommunication among TIME components present potential targets for prognosis prediction and treatment in cancer.Thus,we concluded novel cell clusters of cancerassociated fibroblasts(CAFs),T cells,tumour-associated macrophages(TAMs)and dendritic cells(DCs)discovered after the application of scRNA-seq in TIME.We also proposed the development of TAMs and exhausted T cells,as well as the possible targets to interrupt the process.In addition,the therapeutic interventions based on cellular interactions in TIME were also summarized.For decades,quantification of the TIME components has been adopted in clinical practice to predict patient survival and response to therapy and is expected to play an important role in the precise treatment of cancer.Summarizing the current findings,we believe that advances in technology and wide application of single-cell analysis can lead to the discovery of novel perspectives on cancer therapy,which can subsequently be implemented in the clinic.Finally,we propose some future directions in the field of TIME studies that can be aided by scRNA-seq technology.

Intratumour microbiome of pancreatic cancer

Pancreatic cancer is a high mortality malignancy with almost equal mortality and morbidity rates.Both normal and tumour tissues of the pancreas were previously considered sterile.In recent years,with the development of technologies for highthroughput sequencing,a variety of studies have revealed that pancreatic cancer tissues contain small amounts of bacteria and fungi.The intratumour microbiome is being revealed as an influential contributor to carcinogenesis.The intratumour microbiome has been identified as a crucial factor for pancreatic cancer progression,diagnosis,and treatment,chemotherapy resistance,and immune response.A better understanding of the biology of the intratumour microbiome of pancreatic cancer contributes to the establishment of better early cancer screening and treatment strategies.This review focuses on the possible origins of the intratumour microbiome in pancreatic cancer,the intratumour localization,the interaction with the tumour microenvironment,and strategies for improving the outcome of pancreatic cancer treatment.Thus,this review offers new perspectives for improving the prognosis of pancreatic cancer.

Elevated peripheral blood neutrophil-to-lymphocyte ratio is associated with an immunosuppressive tumour microenvironment and decreased benefit of PD-1 antibody in advanced gastric cancer

Background Due to its limited efficacy and potential toxicity,anti-PD-1 monoclonal antibody is not suitable for all advanced gastric cancer(AGC)patients and predictive biomarkers identifying patients who can benefit from it are urgently needed.This study aimed to evaluate the predictive and prognostic value of inflammatory markers in the context of the systemic inflammatory status and tumour microenvironment.Methods The study included 58 patients from a prospective study investigating the safety and efficacy of toripalimab in chemorefractory AGC patients.Patient characteristics,treatment outcomes,and haematological parameters were analysed.Immune-cell infiltration and gene expression in tumour tissue were examined using transcriptome sequencing.Results In this cohort,the median follow-up time was 4.5 months,the median progression-free survival was 1.9 months,and the median overall survival(OS)was 4.8 months.The objective response rate was 12.1%and th disease control rate(DCR)was 39.7%.Both the baseline blood neutrophil-to-lymphocyte ratio(bNLR)with a cut-point of 2.7 and the early elevated dynamic change of the bNLR(dNLR)with a cut-point of 1.5 were prognostic factors of survival.Patients in the high bNLR or dNLR group had remarkably poor DCR(25.8%vs 59.1%,P=0.023;15.8%vs 54.6%,P=0.008).In multivariate analysis,bNLR and tumour mutational burden were independent prognostic factors of OS.Tumour RNA-seq analysis revealed enriched neutrophil infiltration and a higher tumour NLR in the bNLR-high group.Corresponding tumour gene-expression profiles were associated with neutrophil recruitment and inflammatory cytokine aggregation.Conclusions Our study demonstrated the potential clinical utility of NLR as a biomarker for patient selection and clinical management in predicting the prognosis of AGC patients as well as response to anti-PD-1 therapy.In addition,high bNLR reflected the imbalance of tumour-tissue-infiltrating neutrophils and lymphocytes,and was associated with an immunosuppressive and pro-tumour microenvironment.

Tricking the tumour microenvironment into becoming our best rational drug design factory:reversal of immune suppression

The immune cellular components of the tumour microenvironment are a diverse group of cells that paradoxically are now appreciated to have a coordinated opposing duality of either promoting or retarding tumour growth.Manipulating this seemingly dynamic interaction for therapeutic benefit is a hotbed of much research.Recent findings in tumour immunology(both preclinical and clinical)build on more than a century of insights and provide a way forward to improving patient outcomes,long term survival and the predictability of“cures”.This opinion piece attempts to summarise some of these historical and contemporary insights with a view to describing eminently testable therapeutic solutions.

Immune microenvironment of medulloblastoma:The association between its molecular subgroups and potential targeted immunotherapeutic receptors

Medulloblastoma(MB)is considered the commonest malignant brain tumor in children.Multimodal treatments consisting of surgery,radiation,and chemotherapy have improved patients’survival.Nevertheless,the recurrence occurs in 30%of cases.The persistent mortality rates,the failure of current therapies to extend life expectancy,and the serious complications of non-targeted cytotoxic treatment indicate the need for more refined therapeutic approaches.Most MBs originating from the neurons of external granular layer line the outer surface of neocerebellum and responsible for the afferent and efferent connections.Recently,MBs have been segregated into four molecular subgroups:Wingless-activated(WNT-MB)(Group 1);Sonichedgehog-activated(SHH-MB)(Group 2);Group 3 and 4 MBs.These molecular alterations follow specific gene mutations and disease-risk stratifications.The current treatment protocols and ongoing clinical trials against these molecular subgroups are still using common chemotherapeutic agents by which their efficacy have improved the progression-free survival but did not change the overall survival.However,the need to explore new therapies targeting specific receptors in MB microenvironment became essential.The immune microenvironment of MBs consists of distinctive cellular heterogeneities including immune cells and none-immune cells.Tumour associate macrophage and tumour infiltrating lymphocyte are considered the main principal cells in tumour microenvironment,and their role are still under investigation.In this review,we discuss the mechanism of interaction between MB cells and immune cells in the microenvironment,with an overview of the recent investigations and clinical trials.

Non-invasive assessment for intratumoural distribution of interstitial fluid flow

Interstitial fluid plays a vital role in drug delivery and tumour treatment.However,few non-invasive measurement methods are available for measuring low-velocity biological fluid flow.Therefore,this study aimed to develop a novel technology called interstitial flow velocity-MRI.The interstitial flow velocity-MRI sequence consists of a dual inversion recovery preparation and an improved stimulated echo sequence(ISTE)combined with phase-contrast MRI.A homemade flow phantom was used to assess the feasibility and sensitivity of interstitial flow velocity-MRI.In addition,xenografts of female BALB/c mouse models of 4T1 breast cancer administered losartan(40 mg/kg)or saline(n?6)were subjected to imaging on a 7.0 T scanner to assess the in vivo interstitial fluid flow velocity.The results showed a significant correlation(P<0.001)between the theoretical velocities and velocities measured using the flow phantom.Interstitial flow velocity-MRI could detect a velocity as low as 10.21±2.65 mm/s with a spatial resolution of 0.313 mm.The losartan group had a lower mean interstitial fluid velocity than the control group(85±16 vs 113±24 mm/s).In addition,compared to the saline treatment,losartan treatment reduced the proportion of collagen fibres by 10%and 12%in the Masson and Sirius red staining groups,respectively.Interstitial flow velocity-MRI has the potential to determine interstitial fluid flow velocity non-invasively and exhibits an intuitive velocity map.

Stromal inflammation,fibrosis and cancer:An old intuition with promising potential

It is now well established that the biology of cancer is influenced by not only malignant cells but also other components of the tumour microenvironment.Chronic inflammation and fibrosis have long been postulated to be involved in carcinogenesis.Chronic inflammation can promote tumorigenesis via growth factor/cytokine-mediated cellular proliferation,apoptotic resistance,immunosuppression;and free-radical-induced oxidative deoxyribonucleic acid damage.Fibrosis could cause a perturbation in the dynamics of the tumour microenvironment,potentially damaging the genome surveillance machinery of normal epithelial cells.In this review,we will provide an in-depth discussion of various diseases characterised by inflammation and fibrosis that have been associated with an increased risk of malignancy.In particular,we will present a comprehensive overview of the impact of alterations in stromal composition on tumorigenesis,induced as a consequence of inflammation and/or fibrosis.Strategies including the application of various therapeutic agents with stromal manipulation potential and targeted cancer screening for certain inflammatory diseases which can reduce the risk of cancer will also be discussed.

Preliminary Exploration of the Clinical Features and Immunological Correlation between TIGIT and Esophageal Squamous Cell Carcinoma

Objective: To analyze the relationship between TIGIT and clinical features of Esophageal Squamous Cell Carcinoma, we use transcriptomic data from the TCGA database, and to investigate the relationship between TIGIT and the immune microenvironment of Esophageal Squamous Cell Carcinoma, to provide a basis for improving the treatment strategy and prognosis of patients with Esophageal Squamous Cell Carcinoma. Methods: RNA sequencing data and clinical data corresponding to cancer tissues were obtained from the TCGA database for Esophageal carcinoma, Esophageal Squamous Cell Carcinoma tissues, and paraneoplastic tissues;then we analyzed the differences in TIGIT expression in Esophageal carcinoma, Esophageal Squamous Cell Carcinoma, and normal esophageal tissues;then we analyzed the relationship between TIGIT expression levels and overall survival in Esophageal Squamous Cell Carcinoma;finally, we explored the relationship between TIGIT expression levels and overall survival in Esophageal Squamous Cell Carcinoma. We investigated the relationship between TIGIT and the tumor immune microenvironment of Esophageal Squamous Cell Carcinoma by tumor immune infiltration and functional enrichment analysis. Results: Our study revealed that TIGIT was highly expressed in Esophageal Squamous Cell Carcinoma, and patients with high TIGIT expression had worse overall survival. We also found a close relationship between TIGIT expression levels and the immune microenvironment of Esophageal Squamous Cell Carcinoma, with high TIGIT expression positively correlated with multiple immune cells. Conclusion: Our study demonstrates that TIGIT is associated with Esophageal Squamous Cell Carcinoma malignancy and is closely linked to the immune microenvironment. Furthermore, high expression of TIGIT often predicts poorer clinical features.

Shuyu pills inhibit immune escape and enhance chemosensitization in hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)is characterized by dysregulation of the immune microenvironment and the development of chemoresistance.Specifically,expression of the programmed cell death protein 1(PD-1)/programmed cell death 1 ligand 1(PD-L1)axis,an immune checkpoint,may lead to tumour immune escape,resulting in disease progression.The latest research shows that tumour immune escape may be caused by the upregulation of PD-L1 mediated by hypoxia-inducible factor-1 alpha(HIF-1α),and simultaneous inhibition of HIF-1αand PD-L1 has the potential to enhance the host’s antitumour immunity.Moreover,inhibition of the PD-1/PD-L1 axis may mitigate tumour chemoresistance.Shuyu pills(SYPs)contain immunity-enhancing and antitumour components,making them a potential HCC treatment.AIM To investigate the efficacy of SYPs for HCC treatment via simultaneous HIF-1α and PD-L1 inhibition and the mechanism involved.METHODS A subcutaneous xenograft tumour model was first established in BALB/c nude mice by the subcutaneous injection of 1×107 SMMC-7721 cells.Male mice(male,5 weeks old;n=24)were then randomly divided into the following four groups(n=6):Control(0.9%normal saline),SYP(200 mg/kg),SYP+cisplatin(DDP)(200 mg/kg+5 mg/kg DDP weekly via intraperitoneal injection),and DDP(5 mg/kg cisplatin weekly via intraperitoneal injection).The dose of saline or SYPs for the indicated mouse groups was 0.2 mL/d via intragastric administration.The tumour volumes and body weights of the mice were measured every 2 d.The mice were euthanized by cervical dislocation after 14 d of continuous treatment,and the xenograft tissues were excised and weighed.Western blot assays were used to measure the protein expression of HIF-1α,PD1,PD-L1,CD4+T cells,and CD8+T cells in HCC tumours from mice.Quantitative reverse transcription polymerase chain reaction was used for real-time quantitative detection of PD-1,PD-L1,and HIF-1α mRNA expression.An immunofluorescence assay was conducted to examine the expression of CD4+T cells and CD8+T cells.RESULTS Compared to mice in the control group,those in the SYP and SYP+DDP groups exhibited reduced tumour volumes and tumour weights.Moreover,the protein and mRNA expression levels of the oncogene HIF1α and that of the negative immunomodulatory factors PD-1 and PD-L1 were decreased in both the SYP and SYP+DDP groups,with the decrease effects being more prominent in the SYP+DDP group than in the SYP group(HIF-1α protein:Control vs SYP,P=0.0129;control vs SYP+DDP,P=0.0004;control vs DDP,P=0.0152,SYP+DDP vs DDP,P=0.0448;HIF-1αmRNA:control vs SYP,P=0.0009;control vs SYP+DDP,P<0.0001;control vs DDP,P=0.0003,SYP vs SYP+DDP,P=0.0192.PD-1 protein:Control vs SYP,P=0.0099;control vs SYP+DDP,P<0.0001,SPY vs SYP+DDP,P=0.0009;SYP+DDP vs DDP,P<0.0001;PD-1 mRNA:control vs SYP,P=0.0002;control vs SYP+DDP,P<0.0001;control vs DDP,P=0.0003,SPY vs SYP+DDP,P=0.0003;SYP+DDP vs DDP,P=0.0002.PD-L1 protein:control vs SYP,P<0.0001;control vs SYP+DDP,P<0.0001;control vs DDP,P<0.0001,SPY vs SYP+DDP,P=0.0040;SYP+DDP vs DDP,P=0.0010;PD-L1 mRNA:Control vs SYP,P<0.0001;control vs SYP+DDP,P<0.0001;control vs DDP,P<0.0001,SPY vs SYP+DDP,P<0.0001;SYP+DDP vs DDP,P=0.0014).Additionally,the quantitative and protein expression levels of CD4+T cells and CD8+T cells were simultaneously upregulated in the SYP+DDP group,whereas only the expression of CD4+T cells was upregulated in the SYP group.(CD4+T cell quantitative:Control vs SYP+DDP,P<0.0001,SYP vs SYP+DDP,P=0.0005;SYP+DDP vs DDP,P=0.0002.CD4+T cell protein:Control vs SYP,P=0.0033;Control vs SYP+DDP,P<0.0001;Control vs DDP,P=0.0021,SYP vs SYP+DDP,P=0.0004;SYP+DDP vs DDP,P=0.0006.Quantitative CD8+T cells:Control vs SYP+DDP,P=0.0013;SYP vs SYP+DDP,P=0.0347;SYP+DDP vs DDP,P=0.0043.CD8+T cell protein:Control vs SYP+DDP,P<0.0001;SYP vs SYP+DDP,P<0.0001;SYP+DDP vs DDP,P<0.0001).Finally,expression of HIF-1αwas positively correlated with that of PD-1/PD-L1 and negatively correlated with the expression of CD4+T cells and CD8+T cells.CONCLUSION SYPs inhibit immune escape and enhance chemosensitization in HCC via simultaneous inhibition of HIF-1α and PD-L1,thus inhibiting the growth of subcutaneous xenograft HCC tumours.

Mechanisms involved in selecting and maintaining neuroblastoma cancer stem cell populations, and perspectives for therapeutic targeting

Pediatric neuroblastomas(NBs)are heterogeneous,aggressive,therapy-resistant embryonal tumours that originate from cells of neural crest(NC)origin and in particular neuroblasts committed to the sympathoadrenal progenitor cell lineage.Therapeutic resistance,post-therapeutic relapse and subsequent metastatic NB progression are driven primarily by cancer stem cell(CSC)-like subpopulations,which through their self-renewing capacity,intermittent and slow cell cycles,drug-resistant and reversibly adaptive plastic phenotypes,represent the most important obstacle to improving therapeutic outcomes in unfavourable NBs.In this review,dedicated to NB CSCs and the prospects for their therapeutic eradication,we initiate with brief descriptions of the unique transient vertebrate embryonic NC structure and salient molecular protagonists involved NC induction,specification,epithelial to mesenchymal transition and migratory behaviour,in order to familiarise the reader with the embryonic cellular and molecular origins and background to NB.We follow this by introducing NB and the potential NC-derived stem/progenitor cell origins of NBs,before providing a comprehensive review of the salient molecules,signalling pathways,mechanisms,tumour microenvironmental and therapeutic conditions involved in promoting,selecting and maintaining NB CSC subpopulations,and that underpin their therapy-resistant,self-renewing metastatic behaviour.Finally,we review potential therapeutic strategies and future prospects for targeting and eradication of these bastions of NB therapeutic resistance,post-therapeutic relapse and metastatic progression.

基于津液论自噬与肿瘤

微环境性自噬促进肿瘤发展,其过程与津液代谢异常导致的痰瘀毒结密切相关。津液敷布有赖于气化功能,痰浊与津液的本质区别在于气化正常与否,气化过亢与不利所致的代谢异常与自噬水平的"太过不及"导致肿瘤增殖发展机制趋同,表明津液代谢变化与自噬水平高低关系密切,自噬的"太过不及"实质是津液气化微观生物行为的异常改变,是肿瘤发生发展的关键驱动因素。故基于津液论述自噬与肿瘤的作用机制,可为中医药干预肿瘤细胞自噬提供新的切入点,丰富中医药防治肿瘤的临证手段和治未病研究。

T cells in pancreatic cancer stroma

Pancreatic ductal adenocarcinoma(PDAC)is a highly devastating disease with a dismal 5-year survival rate.PDAC has a complex tumour microenvironment;characterised by a robust desmoplastic stroma,extensive infiltration of immunesuppressive cells such as immature myeloid cells,tumour-associated macrophages,neutrophils and regulatory T cells,and the presence of exhausted and senescent T cells.The cross-talk between cells in this fibrotic tumour establishes an immune-privileged microenvironment that supports tumour cell escape from immune-surveillance,disease progression and spread to distant organs.PDAC tumours,considered to be non-immunogenic or cold,express low mutation burden,low infiltration of CD8+cytotoxic lymphocytes that are localised along the invasive margin of the tumour border in the surrounding fibrotic tissue,and often display an exhausted phenotype.Here,we review the role of T cells in pancreatic cancer,examine the complex interactions of these crucial effector units within pancreatic cancer stroma and shed light on the increasingly attractive use of T cells as therapy.

Modulation of the immune response by heterogeneous monocytes and dendritic cells in lung cancer

Different subpopulations of monocytes and dendritic cells(DCs)may have a key impact on the modulation of the immune response in malignancy.In this review,we summarize the monocyte and DCs heterogeneity and their function in the context of modulating the immune response in cancer.Subgroups of monocytes may play opposing roles in cancer,depending on the tumour growth and progression as well as the type of cancer.Monocytes can have pro-tumour and anti-tumour functions and can also differentiate into monocyte-derived DCs(moDCs).MoDCs have a similar antigen presentation ability as classical DCs,including cross-priming,a process by which DCs activate CD8 T-cells by crosspresenting exogenous antigens.DCs play a critical role in generating anti-tumour CD8 T-cell immunity.DCs have plastic characteristics and show distinct phenotypes depending on their mature state and depending on the influence of the tumour microenvironment.MoDCs and other DC subsets have been attracting increased interest owing to their possible beneficial effects in cancer immunotherapy.This review also highlights key strategies deploying specific DC subpopulations in combination with other therapies to enhance the anti-tumour response and summarizes the latest ongoing and completed clinical trials using DCs in lung cancer.

Natural killer cells in pancreatic cancer stroma

Pancreatic cancer remains one of medicine’s largest areas of unmet need.With five-year survival rates of<8%,little improvement has been made in the last 50 years.Typically presenting with advance stage disease,treatment options are limited.To date,surgery remains the only potentially curative option,however,with such late disease presentation,the majority of patients are unresectable.Thus,new therapeutic options and a greater understanding of the complex stromal interactions within the tumour microenvironment are sorely needed to revise the dismal outlook for pancreatic cancer patients.Natural killer(NK)cells are crucial effector units in cancer immunosurveillance.Often used as a prognostic biomarker in a range of malignancies,NK cells have received much attention as an attractive target for immunotherapies,both as cell therapy and as a pharmaceutical target.Despite this interest,the role of NK cells in pancreatic cancer remains poorly defined.Nevertheless,increasing evidence of the importance of NK cells in this dismal prognosis disease is beginning to come to light.Here,we review the role of NK cells in pancreatic cancer,examine the complex interactions of these crucial effector units within pancreatic cancer stroma and shed light on the increasingly attractive use of NK cells as therapy.

Research Progress of Breast Cancer Stem Cell Stemness and Breast Cancer Recurrence

Currently, breast cancer is the most common malignant tumour in Chinese women with a high incidence rate, and recurrence and metastasis are the main reasons affecting survival. Breast Cancer Stem Cells (BCSCs) are stem cells capable of continuous regeneration in vivo with strong self-renewal ability and multidirectional differentiation potential, which are highly tumourigenic and insensitive to radiotherapy and chemotherapy, and are highly susceptible to breast cancer recurrence. Therefore, exploring the stemness of BCSCs and their mechanism associated with recurrence is important for developing new therapeutic strategies, improving therapeutic efficacy, and improving patient prognosis.

A review of strategies to overcome immune resistance in the treatment of advanced prostate cancer

Immunotherapy has become integral in cancer therapeutics over the past two decades and is now part of standard-of-care treatment in multiple cancer types. While various biomarkers and pathway alterations such as dMMR, CDK12, and AR-V7 have been identified in advanced prostate cancer to predict immunotherapy responsiveness, the vast majority of prostate cancer remain intrinsically immune-resistant, as evidenced by low response rates to anti-PD(L)1 monotherapy. Since regulatory approval of the vaccine therapy sipuleucel-T in the biomarker-unselected population, there has not been much success with immunotherapy treatment in advanced prostate cancer. Researchers have looked at various strategies to overcome immune resistance, including the identification of more biomarkers and the combination of immunotherapy with existing effective prostate cancer treatments. On the horizon, novel drugs using bispecific T-cell engager (BiTE) and chimeric antigen receptors (CAR) technology are being explored and have shown promising early efficacy in this disease. Here we discuss the features of the tumour microenvironment that predispose to immune resistance and rational strategies to enhance antitumour responsiveness in advanced prostate cancer.

Immune checkpoint inhibitors in ovarian cancer:where do we go from here?

Epithelial ovarian cancer(EOC)is the most lethal gynaecological malignancy,and despite advancements in therapeutics,most women unfortunately still succumb to their disease.Immunotherapies,in particular immune checkpoint inhibitors(ICI),have been therapeutically transformative in many tumour types,including gynaecological malignancies such as cervical and endometrial cancer.Unfortunately,these therapeutic successes have not been mirrored in ovarian cancer clinical studies.This review provides an overview of the ovarian tumour microenvironment(TME),particularly factors associated with survival,and explores current research into immunotherapeutic strategies in EOC,with an exploratory focus on novel therapeutics in navigating drug resistance.