Hypoxic microenvironment in cancer: molecular mechanisms and therapeutic interventions

Overexpression of ST8Sia1 inhibits tumor progression by TGF-β1 signaling in rectal adenocarcinoma and promotes the tumoricidal effects of CD8+ T cells by granzyme B and perforin

BACKGROUND

Rectal adenocarcinoma (READ) involves the dysregulated expression of alpha 2,8-Sialyltransferase1 (ST8Sia1) although its role during READ's progression is unclear.

METHODS

The mRNA level of ST8Sia1 was analyzed based on The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and Tumor Immune Estimation Resource (TIMER) 2.0. Furthermore, the prognostic and significance of ST8Sia1 in READ was assessed through Kaplan-Meier curve, univariate, multivariate Cox regression, and receiver operating characteristic (ROC) methods. The role of ST8Sia1 in the READ immune microenvironment was explored using ESTIMATE analysis and TIMER databases. Furthermore, the expression of ST8Sia1 in tissues was analyzed using real-time quantitative polymerase chain reaction (RT-qPCR), western blotting (WB), and immunohistochemistry (IHC). Perforin and Granzyme B secretion by CD8+ T cells, as well as tumor cell apoptosis, were detected after co-culturing CD8+ T cells with READ tumor cells and ST8Sia1-overexpression (ST8Sia1-OE) tumor cells. Furthermore, we examined the interaction between ST8Sia1 and TGF-β1 in READ cells.

RESULTS

ST8Sia1 exhibited excellent diagnostic capability for READ, with positive correlations to immune response and negative correlations to tumor purity. Increased levels of perforin and Granzyme B from CD8+ T cells were observed in vitro, enhancing tumor cell apoptosis. ST8Sia1 interacts with TGF-β1, mediating its inhibitory effects on READ development.

CONCLUSIONS

ST8Sia1 is a potential diagnostic biomarker and therapeutic target for READ, enhancing CD8+ T cell function and possibly improving patient outcomes through cellular immunotherapy.

Frontiers in pancreatic cancer on biomarkers, microenvironment, and immunotherapy

Pancreatic cancer remains one of the most challenging malignancies to treat due to its late-stage diagnosis, aggressive progression, and high resistance to existing therapies. This review examines the latest advancements in early detection, and therapeutic strategies, with a focus on emerging biomarkers, tumor microenvironment (TME) modulation, and the integration of artificial intelligence (AI) in data analysis. We highlight promising biomarkers, including microRNAs (miRNAs) and circulating tumor DNA (ctDNA), that offer enhanced sensitivity and specificity for early-stage diagnosis when combined with multi-omics panels. A detailed analysis of the TME reveals how components such as cancer-associated fibroblasts (CAFs), immune cells, and the extracellular matrix (ECM) contribute to therapy resistance by creating immunosuppressive barriers. We also discuss therapeutic interventions that target these TME components, aiming to improve drug delivery and overcome immune evasion. Furthermore, AI-driven analyses are explored for their potential to interpret complex multi-omics data, enabling personalized treatment strategies and real-time monitoring of treatment response. We conclude by identifying key areas for future research, including the clinical validation of biomarkers, regulatory frameworks for AI applications, and equitable access to innovative therapies. This comprehensive approach underscores the need for integrated, personalized strategies to improve outcomes in pancreatic cancer.

Interactions between ferroptosis and tumour development mechanisms: Implications for gynaecological cancer therapy (Review)

Ferroptosis is a form of programmed cell death that is distinct from apoptosis. The mechanism involves redox‑active metallic iron and is characterized by an abnormal increase in iron‑dependent lipid reactive oxygen species, which results in high levels of membrane lipid peroxides. The relationship between ferroptosis and gynaecological tumours is complex. Ferroptosis can regulate tumour proliferation, metastasis and chemotherapy resistance, and targeting ferroptosis is a promising antitumour approach. Ferroptosis interacts with mechanisms related to tumorigenesis and development, such as macrophage polarization, the neutrophil trap network, mitochondrial autophagy and cuproptosis. The present review examines recent information on the interaction between the molecular mechanism of ferroptosis and other tumour‑related mechanisms, as well as the involvement of ferroptosis in gynaecological tumours, to identify implications for gynaecological cancer therapy.

Dual-phase nanoscissors disrupt vasculature-breast cancer stem cell crosstalk for breast cancer treatment

Clinical treatment effects of breast cancer are heavily frustrated by the malignant crosstalk between tumor vasculature and breast cancer stem cells (BCSCs). This study introduces a two-phase therapeutic strategy targeting the interplay between tumor vasculature and BCSCs to overcome this challenge. Here, we an FLG/ZnPc nanoscissor, which combines mild photodynamic therapy (PDT) to generate reactive oxygen species (ROS) with vascular normalization therapy (VNT) to break the crosstalk between tumor vasculature and BCSCs. In the first phase, our approach breaks the vascular niche that supports BCSCs by restoring tumor vascular function and promoting ROS-induced BCSCs differentiation into less malignant forms, enhancing treatment sensitivity. The second phase employs high-impact photothermal therapy (PTT) to ablate tumor masses. This integrated "mild PDT-PTT" approach aims to reduce tumor growth and metastasis, offering a comprehensive strategy for effective breast cancer management.

Assessment of Hypoxia in Breast Cancer: Emerging Functional MR Imaging and Spectroscopy Techniques and Clinical Applications

Breast cancer is one of the most prevalent forms of cancer affecting women worldwide. Hypoxia, a condition characterized by insufficient oxygen supply in tumor tissues, is closely associated with tumor aggressiveness, resistance to therapy, and poor clinical outcomes. Accurate assessment of tumor hypoxia can guide treatment decisions, predict therapy response, and contribute to the development of targeted therapeutic interventions. Over the years, functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS) techniques have emerged as promising noninvasive imaging options for evaluating hypoxia in cancer. Such techniques include blood oxygen level-dependent (BOLD) MRI, oxygen-enhanced MRI (OE) MRI, chemical exchange saturation transfer (CEST) MRI, and proton MRS (1H-MRS). These may help overcome the limitations of the routinely used dynamic contrast-enhanced (DCE) MRI and diffusion-weighted imaging (DWI) techniques, contributing to better diagnosis and understanding of the biological features of breast cancer. This review aims to provide a comprehensive overview of the emerging functional MRI and MRS techniques for assessing hypoxia in breast cancer, along with their evolving clinical applications. The integration of these techniques in clinical practice holds promising implications for breast cancer management. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 1.

Tumor microenvironment-modulated nanoparticles with cascade energy transfer as internal light sources for photodynamic therapy of deep-seated tumors

Photodynamic therapy (PDT) is an appealing modality for cancer treatments. However, the limited tissue penetration depth of external-excitation light makes PDT impossible in treating deep-seated tumors. Meanwhile, tumor hypoxia and intracellular reductive microenvironment restrain the generation of reactive oxygen species (ROS). To overcome these limitations, a tumor-targeted self-illuminating supramolecular nanoparticle T-NPCe6-L-N is proposed by integrating photosensitizer Ce6 with luminol and nitric oxide (NO) for chemiluminescence resonance energy transfer (CRET)-activated PDT. The high H2O2 level in tumor can trigger chemiluminescence of luminol to realize CRET-activated PDT without exposure of external light. Meanwhile, the released NO significantly relieves tumor hypoxia via vascular normalization and reduces intracellular reductive GSH level, further enhancing ROS abundance. Importantly, due to the different ROS levels between cancer cells and normal cells, T-NPCe6-L-N can selectively trigger PDT in cancer cells while sparing normal cells, which ensured low side effect. The combination of CRET-based photosensitizer-activation and tumor microenvironment modulation overcomes the innate challenges of conventional PDT, demonstrating efficient inhibition of orthotopic and metastatic tumors on mice. It also provoked potent immunogenic cell death to ensure long-term suppression effects. The proof-of-concept research proved as a new strategy to solve the dilemma of PDT in treatment of deep-seated tumors.

Application and progress of 3D tumor models in breast cancer

Due to its high heterogeneity and significant impact on women's health globally, breast cancer necessitates robust preclinical models to understand tumor biology and guide personalized treatment strategies. Three-dimensional (3D) in vitro tumor models hold immense promise in this regard. These tumor models not only mimic the spatial structure and growth environment of tumors in vivo, but also retain the pathological and genetic characteristics of solid tumors. This fidelity makes them powerful tools for accelerating advancements in fundamental research and translational medicine. The diversity, modularity, and efficacy of 3D tumor models are driving a biotechnological revolution. As these technologies become increasingly sophisticated, 3D tumor models are poised to become powerful weapons in the fight against breast cancer. This article expounds on the progress made in utilizing 3D tumor models for breast cancer research.

Advancements in understanding the molecular mechanisms and clinical implications of Von Hippel-Lindau syndrome: A comprehensive review

Von Hippel-Lindau Syndrome (VHL) is a rare genetic disorder characterized by tumors in multiple organs, including the kidneys, pancreas, and central nervous system. This comprehensive review discusses the genetic basis and clinical manifestations of VHL, as well as recent advancements in understanding the molecular mechanisms that lead to tumor formation. The authors highlight the role of hypoxia-inducible factors and the ubiquitin-proteasome system in VHL-associated cancer development .The review also discusses the potential clinical implications of these findings, such as the development of targeted therapies for VHL-associated cancers. However, the authors note the challenges associated with developing effective treatments for this complex disease, including limited patient availability for clinical trials due to its rarity .Overall, this review provides valuable insights into our current understanding of VHL and offers important avenues for future research aimed at improving the diagnosis, treatment, and management of VHL patients. By illuminating the molecular underpinnings of VHL-associated cancers, this work may ultimately help to develop more effective treatments and improve outcomes for patients with this challenging disease.

Autophagy as a Therapeutic Target in Breast Tumors: The Cancer stem cell perspective

Breast cancer is a heterogeneous disease, with a subpopulation of tumor cells known as breast cancer stem cells (BCSCs) with self-renewal and differentiation abilities that play a critical role in tumor initiation, progression, and therapy resistance. The tumor microenvironment (TME) is a complex area where diverse cancer cells reside creating a highly interactive environment with secreted factors, and the extracellular matrix. Autophagy, a cellular self-digestion process, influences dynamic cellular processes in the tumor TME integrating diverse signals that regulate tumor development and heterogeneity. Autophagy acts as a double-edged sword in the breast TME, with both tumor-promoting and tumor-suppressing roles. Autophagy promotes breast tumorigenesis by regulating tumor cell survival, migration and invasion, metabolic reprogramming, and epithelial-mesenchymal transition (EMT). BCSCs harness autophagy to maintain stemness properties, evade immune surveillance, and resist therapeutic interventions. Conversely, excessive, or dysregulated autophagy may lead to BCSC differentiation or cell death, offering a potential avenue for therapeutic exploration. The molecular mechanisms that regulate autophagy in BCSCs including the mammalian target of rapamycin (mTOR), AMPK, and Beclin-1 signaling pathways may be potential targets for pharmacological intervention in breast cancer. This review provides a comprehensive overview of the relationship between autophagy and BCSCs, highlighting recent advancements in our understanding of their interplay. We also discuss the current state of autophagy-targeting agents and their preclinical and clinical development in BCSCs.

The interplay between the tumor microenvironment and tumor-derived small extracellular vesicles in cancer development and therapeutic response

The tumor microenvironment (TME) plays an essential role in tumor cell survival by profoundly influencing their proliferation, metastasis, immune evasion, and resistance to treatment. Extracellular vesicles (EVs) are small particles released by all cell types and often reflect the state of their parental cells and modulate other cells' functions through the various cargo they transport. Tumor-derived small EVs (TDSEVs) can transport specific proteins, nucleic acids and lipids tailored to propagate tumor signals and establish a favorable TME. Thus, the TME's biological characteristics can affect TDSEV heterogeneity, and this interplay can amplify tumor growth, dissemination, and resistance to therapy. This review discusses the interplay between TME and TDSEVs based on their biological characteristics and summarizes strategies for targeting cancer cells. Additionally, it reviews the current issues and challenges in this field to offer fresh insights into comprehending tumor development mechanisms and exploring innovative clinical applications.

MOICS, a novel classier deciphering immune heterogeneity and aid precise management of clear cell renal cell carcinoma at multiomics level

Recent studies have indicated that the tumor immune microenvironment plays a pivotal role in the initiation and progression of clear cell renal cell carcinoma (ccRCC). However, the characteristics and heterogeneity of tumor immunity in ccRCC, particularly at the multiomics level, remain poorly understood. We analyzed immune multiomics datasets to perform a consensus cluster analysis and validate the clustering results across multiple internal and external ccRCC datasets; and identified two distinctive immune phenotypes of ccRCC, which we named multiomics immune-based cancer subtype 1 (MOICS1) and subtype 2 (MOICS2). The former, MOICS1, is characterized by an immune-hot phenotype with poor clinical outcomes, marked by significant proliferation of CD4+ and CD8+ T cells, fibroblasts, and high levels of immune inhibitory signatures; the latter, MOICS2, exhibits an immune-cold phenotype with favorable clinical characteristics, characterized by robust immune activity and high infiltration of endothelial cells and immune stimulatory signatures. Besides, a significant negative correlation between immune infiltration and angiogenesis were identified. We further explored the mechanisms underlying these differences, revealing that negatively regulated endopeptidase activity, activated cornification, and neutrophil degranulation may promote an immune-deficient phenotype, whereas enhanced monocyte recruitment could ameliorate this deficiency. Additionally, significant differences were observed in the genomic landscapes between the subtypes: MOICS1 exhibited mutations in TTN, BAP1, SETD2, MTOR, MUC16, CSMD3, and AKAP9, while MOICS2 was characterized by notable alterations in the TGF-β pathway. Overall, our work demonstrates that multi-immune omics remodeling analysis enhances the understanding of the immune heterogeneity in ccRCC and supports precise patient management.

Targeting hypoxia and angiogenesis in hepatocellular carcinoma: New insights and therapeutic strategies

In this manuscript we comment on the article by Yang et al published recently, focusing on how hepatic angiopoietin-2 (Ang-2) transcription promote the progression of hepatocellular carcinoma (HCC). HCC is one of the most common and lethal malignancies worldwide, especially in regions with high hepatitis B virus infection rates. Ang-2 is a key mediator of angiogenesis and plays a significant role in the progression of chronic liver diseases towards HCC, particularly in the hypoxic microenvironment. This paper reviews the dynamic expression of Ang-2 in hepatocarcinogenesis and its regulation by hypoxia-inducible factor-1α. Furthermore, we discuss Ang-2’s potential as an early monitoring biomarker for metastasis, and the therapeutic prospects of silencing hypoxia-inducible factor-1α to downregulate Ang-2 and suppress epithelial-mesenchymal transition in HCC treatment.

Assessing the causality between pulmonary arterial hypertension and cancer: insights from Mendelian randomization

BACKGROUND

Previous clinical studies have suggested an increased risk of tumor development in patients with pulmonary arterial hypertension (PAH). However, it remains unclear whether there is a causal relationship between PAH and tumor occurrence. This study investigates the causal link between PAH and cancer from a genetic perspective using Mendelian randomization (MR).

METHOD

Genome-wide association study (GWAS) summary data for PAH and various common cancer types were obtained from the GWAS Catalog. Single nucleotide polymorphisms (SNPs) significantly associated with PAH at the genome-wide significance threshold (P < 1 × 10-6) were selected as instrumental variables (IVs). Inverse-variance weighted (IVW) was used as the primary method for MR analysis, with sensitivity analyses including tests for heterogeneity and horizontal pleiotropy.

RESULTS

The results from the IVW analysis indicate that genetically proxied PAH is associated with an increased risk of liver cancer [odd ratio (OR) 1.11, 95% confidence interval (CI) 1.01-1.22, P = 0.025), while showing no significant causal relationship with other common types of tumors (thyroid cancer: OR 0.95, 95% CI 0.86-1.06, P = 0.360; lung cancer: OR 0.95, 95% CI 0.90-1.01, P = 0.129; gastric cancer: OR 0.97, 95% CI 0.93-1.02, P = 0.243; colorectal cancer: OR 1.01, 95% CI 0.98-1.05, P = 0.412). Except for the MR analysis examining the causal effect of PAH on lung cancer (P = 0.049), the remaining MR analyses displayed no significant heterogeneity (P > 0.05). Additionally, the MR-Egger intercept test did not find evidence of horizontal pleiotropy (P > 0.05).

CONCLUSION

This study highlights that PAH may serve as a potential risk factor for this liver cancer. Future research should aim to elucidate the biological mechanisms at play and explore the potential for early interventions that could mitigate cancer risk in this vulnerable population.

Decoding the complex web: Cellular and molecular interactions in the lung tumor microenvironment

The lung tumor microenvironment (TME) or stroma is a dynamic space of numerous cells and their released molecules. This complicated web regulates tumor progression and resistance to different modalities. Lung cancer cells in conjunction with their stroma liberate a wide range of factors that dampen antitumor attacks by innate immunity cells like natural killer (NK) cells and also adaptive responses by effector T cells. These factors include numerous growth factors, exosomes and epigenetic regulators, and also anti-inflammatory cytokines. Understanding the intricate interactions between tumor cells and various elements within the lung TME, such as immune and stromal cells can help provide novel strategies for better management and treatment of lung malignancies. The current article discusses the complex network of cells and signaling molecules, which mediate communications in lung TME. By elucidating these multifaceted interactions, we aim to provide insights into potential therapeutic targets and strategies for lung cancer treatment.

Molecular and functional profiling of primary normal ovarian cells defines insights into cancer development and drug responses

Patients with ovarian cancer, especially the high-grade serous ovarian cancer (HGSOC) subtype, face poor prognosis due to late diagnosis and treatment resistance. Owing to the high heterogeneity of HGSOC, identifying the origin of the disease and optimal treatments is difficult. Here, we characterized two primary immortalized human ovarian cell lines, human ovarian surface epithelium (HOSE)1C and HOSE2C, comparing their molecular profiling with representative HGSOC cells. We identified molecular features associated with normal and malignant phenotype of ovarian cells by applying single-cell transcriptomics, high-content image-based cell painting, and high-throughput drug testing. Our findings reveal distinct transcriptomic and morphological profiles for the two HOSEs, with a stromal phenotype. Moreover, their responses to the tumor microenvironment differ, exemplified by STAT1 and GREM1 upregulation in HOSE1C and HOSE2C, respectively. We identified selective activation of ERK/MEK targeted inhibitors in cancer cells compared to HOSEs. This study offers insights into the normal and malignant ovarian cells, shedding light on cancer development and drug responses.

Nuclear Overexpression of SAMHD1 Induces M Phase Stalling in Hepatoma Cells and Suppresses HCC Progression by Interacting with the Cohesin Complex

Emerging evidence suggests that the sterile alpha-motif (SAM) and histidine-aspartate (HD) domain-containing protein 1 (SAMHD1) is implicated in various cancers, including hepatocellular carcinoma (HCC). However, its precise role in tumor cells and the underlying mechanisms remain unclear. This study aimed to investigate the expression patterns, prognostic values, and functional role of SAMHD1 in HCC progression. We constructed liver tissue microarrays using tumor and paired paratumor tissue specimens from 187 patients with primary HCC. Our findings indicate that nuclear SAMHD1 protein levels are increased in tumors compared to paratumor tissues. Moreover, nuclear SAMHD1 levels decline in advanced tumor stages, with higher SAMHD1 nuclear staining correlating with favorable prognostic outcomes. Hepatocyte-specific SAMHD1 knockout mice, generated by crossing SAMHD1fl/fl mice with Alb-cre mice, showed accelerated tumor progression in a diethylnitrosamine (DEN)-induced HCC model. In hepatoma cell lines, nuclear overexpression of SAMHD1 inhibited cell proliferation by stalling mitosis, independent of its deoxynucleotide triphosphohydrolase (dNTPase) function. Mechanistically, SAMHD1 interacts with the cohesin complex in nucleus, enhancing sister chromatid cohesion during cell division, which delays metaphase progression. Our findings suggest that nuclear SAMHD1 plays a critical role in slowing HCC progression by regulating mitosis, highlighting its potential as a therapeutic target by manipulating cohesin dynamics.

Immunometabolism in head and neck squamous cell carcinoma: Hope and challenge

Immunotherapy has improved the survival rate of patients with head and neck squamous cell carcinoma (HNSCC), but less than 20 % of them have a durable response to these treatments. Excessive local recurrence and lymph node metastasis ultimately lead to death, making the 5-year survival rate of HNSCC still not optimistic. Cell metabolism has become a key determinant of the viability and function of cancer cells and immune cells. In order to maintain the enormous anabolic demand, tumor cells choose a specialized metabolism different from non-transformed somatic cells, leading to changes in the tumor microenvironment (TME). In recent years, our understanding of immune cell metabolism and cancer cell metabolism has gradually increased, and we have begun to explore the interaction between cancer cell metabolism and immune cell metabolism in a way which is meaningful for treatment. Understanding the different metabolic requirements of different cells that constitute the immune response to HNSCC is beneficial for revealing metabolic heterogeneity and plasticity, thereby enhancing the effect of immunotherapy. In this review, we have concluded that the relevant metabolic processes that affect the function of immune cells in HNSCC TME and proposed our own opinions and prospects on how to use metabolic intervention to enhance anti-tumor immune responses.

Tumor-Targeted Catalytic Immunotherapy

Cancer immunotherapy holds significant promise for improving cancer treatment efficacy; however, the low response rate remains a considerable challenge. To overcome this limitation, advanced catalytic materials offer potential in augmenting catalytic immunotherapy by modulating the immunosuppressive tumor microenvironment (TME) through precise biochemical reactions. Achieving optimal targeting precision and therapeutic efficacy necessitates a thorough understanding of the properties and underlying mechanisms of tumor-targeted catalytic materials. This review provides a comprehensive and systematic overview of recent advancements in tumor-targeted catalytic materials and their critical role in enhancing catalytic immunotherapy. It highlights the types of catalytic reactions, the construction strategies of catalytic materials, and their fundamental mechanisms for tumor targeting, including passive, bioactive, stimuli-responsive, and biomimetic targeting approaches. Furthermore, this review outlines various tumor-specific targeting strategies, encompassing tumor tissue, tumor cell, exogenous stimuli-responsive, TME-responsive, and cellular TME targeting strategies. Finally, the discussion addresses the challenges and future perspectives for transitioning catalytic materials into clinical applications, offering insights that pave the way for next-generation cancer therapies and provide substantial benefits to patients in clinical settings.

Carbohydrate polymer-based nanoparticles with cell membrane camouflage for cancer therapy: A review

Recent developments in biomimetic nanoparticles, specifically carbohydrate polymer-coated cell membrane nanoparticles, have demonstrated considerable promise in treating cancer. These systems improve drug delivery by imitating natural cell actions, enhancing biocompatibility, and decreasing immune clearance. Conventional drug delivery methods frequently face challenges with non-specific dispersal and immune detection, which can hinder their efficiency and safety. These biomimetic nanoparticles improve target specificity, retention times, and therapeutic efficiency by using biological components like chitosan, hyaluronic acid, and alginate. Chitosan-based nanoparticles, which come from polysaccharides found in nature, have self-assembly abilities that make them better drug carriers. Hyaluronic acid helps target tissues more effectively, especially in cancer environments where there are high levels of hyaluronic acid receptors. Alginate-based systems also enhance drug delivery by being biocompatible and degradable, making them ideal choices for advanced therapeutic uses. Moreover, these particles hold potential for overcoming resistance to multiple drugs and boosting the body's immune reaction to tumors through precise delivery and decreased side effects of chemotherapy drugs. This review delves into the possibilities of using carbohydrate polymer-functionalized nanoparticles and their impact on enhancing the efficacy of cancer treatment.

Hypoxia as a critical player in extracellular vesicles-mediated intercellular communication between tumor cells and their surrounding microenvironment

In the past years, increasing attention has been paid to the role of extracellular vesicles (EVs) as mediators of intercellular communication in cancer. These small size particles mediate the intercellular transfer of important bioactive molecules involved in malignant initiation and progression. Hypoxia, or low partial pressure of oxygen, is recognized as a remarkable feature of solid tumors and has been demonstrated to exert a profound impact on tumor prognosis and therapeutic efficacy. Indeed, the high-pitched growth rate and chaotic neovascular architecture that embodies solid tumors results in a profound reduction in oxygen pressure within the tumor microenvironment (TME). In response to oxygen-deprived conditions, tumor cells and their surrounding milieu develop homeostatic adaptation mechanisms that contribute to the establishment of a pro-tumoral phenotype. Latest evidence suggests that the hypoxic microenvironment that surrounds the tumor bulk may be a clincher for the observed elevated levels of circulating EVs in cancer patients. Thus, it is proposed that EVs may play a role in mediating intercellular communication in response to hypoxic conditions. This review focuses on the EVs-mediated crosstalk that is established between tumor cells and their surrounding immune, endothelial, and stromal cell populations, within the hypoxic TME.

Transition Metal Complex-Loaded Nanosystems: Advances in Stimuli-Responsive Cancer Therapies

Transition metal complex-loaded nanosystems (TMCNs) represent a cutting-edge platform for stimuli (light, ultrasound)-responsive cancer therapies. These nanosystems, incorporating metals such as manganese(II), zinc(II), ruthenium(II), rhenium(I), iridium(III), and platinum(IV), significantly enhance the efficacy of light-activated therapies, including photodynamic therapy (PDT) and photothermal therapy (PTT), as well as ultrasound-activated treatments like sonodynamic therapy (SDT). TMCNs based on ruthenium(II), rhenium(I), and iridium(III) improve PDT, while manganese(II) and iridium(III) demonstrate exceptional sonosensitizing properties. In PTT, ruthenium(II) and iridium(III)-based TMCNs efficiently absorb light and generate heat. Emerging synergistic approaches that combine SDT, PTT, PDT, chemotherapy, and immunotherapy are demonstrated to be powerful strategies for precision cancer treatment. Zinc(II), ruthenium(II), iridium(III), and platinum(IV)-based TMCNs play a critical role in optimizing these therapies, enhancing tumor targeting, and reducing side effects. Furthermore, TMCNs can amplify immunotherapy by inducing immunogenic cell death, thus strengthening the immune response. These advances address key challenges such as tumor hypoxia and therapeutic resistance, opening new possibilities for innovative photosensitizer-based cancer treatments. This review highlights the latest progress in TMCNs design and applications, demonstrating their potential to revolutionize stimuli-responsive cancer therapies.

The role of ceRNAs in breast cancer microenvironmental regulation and therapeutic implications

The tumor microenvironment, which is the tailored physiological milieu of heterogeneous cancer cell populations surrounded by stromal and immune cells as well as extracellular matrix components, is a leading modulator of critical cancer hallmarks and one of the most significant prognostic indicators in breast cancer. In the last few decades, with the discovery of the interactions of ncRNAs with diverse cellular molecules, considerable emphasis has been devoted to understanding their direct and indirect roles in specific functions in breast cancer. Collectively, all of these have revealed that the competitive action of protein-coding RNAs and ncRNAs such as circRNAs and lncRNAs, which have a shared affinity for miRNAs, play a vital role in the molecular regulation of breast cancer. This phenomenon, termed as competing endogenous RNAs (ceRNAs), facilitates modeling the microenvironment through intercellular shuttles. Microenvironment ceRNA interactions have emerged as a frontier in the deep understanding of the complex mechanisms of breast cancer. In this review, we first discuss cellular ceRNAs in four key biological processes critical for microenvironmental regulation in breast cancer tissues: hypoxia, angiogenesis, immune regulations, and ECM remodeling. Further, we draw a complete portrait of microenvironment regulation by cell-to-cell cross-talk of shuttled ceRNAs and offer a framework of potential applications and challenges in overcoming the aggressive phenotype of the breast cancer microenvironment.

One Change, Many Benefits: A Glycine-Modified Bacteriochlorin with NIR Absorption and a Type I Photochemical Mechanism for Versatile Photodynamic Therapy

Difluorinated sulfonamide porphyrin (F2PGly) and bacteriochlorin (F2BGly), modified by glycine residues, were synthesized and evaluated for photodynamic therapy (PDT). F₂PGly exhibits superior stability and singlet oxygen generation efficiency but features a low-intensity band in the red range (λmax = 639 nm). In contrast, F2BGly shows a favorable, red-shifted absorption spectrum (λmax = 746 nm) that aligns well with phototherapeutic window, facilitating deeper tissue penetration. Moreover, it demonstrates reasonable photostability, necessary for the efficient generation of both singlet oxygen (type II) and oxygen-centered radicals (type I mechanism) which contributes to enhanced therapeutic efficacy. Importantly, the glycine modifications in F2BGly enhance its uptake in MCF-7 cells, known for their resistance to PDT due to efflux transport proteins like LAT1, showing great potential in the cancer cell-targeted PDT. The glycine groups potentially enable F2BGly to bypass these barriers, resulting in increased intracellular accumulation and more effective Reactive Oxygen Species (ROS) generation under illumination. In vivo studies indicated promising vascular-targeted PDT results, with real-time fluorescence imaging used to monitor photosensitizer distribution prior to irradiation. These findings suggest that F2BGly is a promising photosensitizer candidate with enhanced cancer cell selectivity and photodynamic efficiency, meriting further exploration in targeted PDT applications for multiple types of cancers.

Integrins and Integrin-Driven Secretory Pathways as Multi-dimensional Regulators of Tumor-Associated Macrophage Recruitment and Reprogramming in Tumor Microenvironment

Integrins, a group of transmembrane receptors, play a crucial role in mediating the interactions between cells and extracellular matrix (ECM) proteins. The intracellular signaling initiated by these cell-matrix interactions in leukocytes mediates many essential cellular processes such as survival, migration, metabolism, and other immunological functions. Macrophages, as phagocytes, participate in both proinflammatory and anti-inflammatory processes, including progression. Numerous reports have shown that the integrin-regulated secretome, comprising cytokines, chemokines, growth factors, proteases, and other bioactive molecules, is a crucial modulator of macrophage functions in tumors, significantly influencing macrophage programming and reprogramming within the tumor microenvironment (TME) in addition to driving their step-by-step entry process into tumor tissue spaces. Importantly, studies have demonstrated a pivotal role for integrin receptor-mediated secretome and associated signaling pathways in functional reprogramming from anti-tumorigenic to pro-tumorigenic phenotype in tumor-associated macrophages (TAMs). In this comprehensive review, we have provided an in-depth analysis of the latest findings of various key pathways, mediators, and signaling cascades associated with integrin-driven polarization of macrophages in tumors. This manuscript will provide an updated understanding of the modulation of inflammatory monocytes/ macrophages and TAMs by integrin-driven secretory pathways in various functions such as migration, differentiation, and their role in tumor progression, angiogenesis, and metastasis.

SENP3-FIS1 axis promotes mitophagy and cell survival under hypoxia

SUMOylation, the covalent attachment of the small ubiquitin-like modifier (SUMO) to target proteins, and its reversal, deSUMOylation by SUMO proteases like Sentrin-specific proteases (SENPs), are crucial for initiating cellular responses to hypoxia. However, their roles in subsequent adaptation processes to hypoxia such as mitochondrial autophagy (mitophagy) remain unexplored. Here, we show that general SUMOylation, particularly SUMO2/3 modification, suppresses mitophagy under both normoxia and hypoxia. Furthermore, we identify deSUMO2/3-ylation enzyme SENP3 and mitochondrial Fission protein 1 (FIS1) as key players in hypoxia-induced mitophagy (HIM), with SUMOylatable FIS1 acting as a crucial regulator for SENP3-mediated HIM regulation. Interestingly, we find that hypoxia promotes FIS1 SUMO2/3-ylation and triggers an interaction between SUMOylatable FIS1 and Rab GTPase-activating protein Tre-2/Bub2/Cdc16 domain 1 family member 17 (TBC1D17), which in turn suppresses HIM. Therefore, we propose a novel SUMOylation-dependent pathway where the SENP3-FIS1 axis promotes HIM, with TBC1D17 acting as a fine-tuning regulator. Importantly, the SENP3-FIS1 axis plays a protective role against hypoxia-induced cell death, highlighting its physiological significance, and hypoxia-inducible FIS1-TBC1D17 interaction is detectable in primary glioma stem cell-like (GSC) cultures derived from glioblastoma patients, suggesting its disease relevance. Our findings not only provide new insights into SUMOylation/deSUMOylation regulation of HIM but also suggest the potential of targeting this pathway to enhance cellular resilience under hypoxic stress.

Dual Porphyrin-Loaded Scintillating Nanoparticles Enhanced Photodynamic Therapy in Hypoxic Cancer Cells under X-ray Irradiation

Tumor hypoxia represents a major challenge to achieving successful therapy outcomes with photodynamic therapy (PDT). We hypothesized that systemic loading of dual porphyrins, protoporphyrin IX (PPIX) as a photosensitizer (PS) and hemin (Fe3+-PPIX) as an oxygen generator, onto Eu-doped NaYF4 scintillator (Sc), collectively terms as Eu-PPIX@Hemin, could enhance the activity of X-ray mediated PDT. Catalase-like property of hemin in the presence of H2O2 facilitated the production of oxygen molecules (3O2) in hypoxic cancer cells. The produced 3O2 reacts with nearby excited PPIX molecules (PPIX*) in the Sc-PS pairs to produce singlet oxygen (1O2), as cytotoxic reactive oxygen species (ROS) under X-ray irradiation. Eu-PPIX@Hemin nanoparticles (NPs) with a diameter of ~60 nm efficiently produced oxygen in the presence of H2O2, which its concentration in tumor cells is higher than that in normal cells. Eu-PPIX@Hemin generated similar amounts of ROS in hypoxic cultured cancer cells under low dose X-ray irradiation (0.5 Gy), compared to those in normoxic cancer cells. Notably, Eu-PPIX@Hemin exhibited similar cytotoxic effects in both hypoxic and normoxic cancer cells under X-ray irradiation. Overall, the mutual Sc-PS performance between PPIX and Eu was synergistically enhanced by hemin in Eu-PPIX@Hemin, which relieved hypoxia in the cancer cells under X-ray irradiation.

Advanced surface-enhanced raman scattering nanoprobes for precise detection of Nitroreductase in Hypoxic tumor cells: Improving Cancer diagnosis

Nitroreductase (NTR) plays a critical role in the oxygen-deficient environment of anoxic tumor cells, and its identification is crucial for the diagnosis and treatment of cancer. This research introduces an innovative Surface Enhanced Raman Scattering (SERS) probe, created by attaching p-nitrothiophenol (p-NTP) to gold nanoparticles (Au NPs). This probe leverages the specific enzymatic reaction of NTR in hypoxic status, utilizing decreased NADH. The enzymatic activity of NTR transforms nitroaromatic compounds into aromatic amines, which is then reflected as a measurable shift in the SERS signal of the probe. This novel approach allows for the accurate quantification of NTR, with the sensitivity reaching a detection threshold of less than 0.02 μg/mL. The probe's non-toxic nature and superior biocompatibility facilitate its use for direct SERS investigations in A549 cells under reduced oxygen levels. We also applied this method to xenograft model. The results demonstrate a marked increase in NTR levels in tumor cells and tumor tissues in hypoxic conditions, highlighting the significance of this nanoprobe in enhancing cancer diagnostics, helping medical doctors making treatment decisions more swiftly and effectively.

Gene expression alterations in hypoxic A549 lung cancer cell line

Human non-small cell lung cancer (NSCLC)is a very common disease with limited treatment options. Hypoxia is a characteristic feature of solid tumors associated with the resistance of cancer cells to radiotherapy and chemotherapy. Therefore, the expression changes in cancer-resistance genes may be biomarkers of hypoxia with value in targeted therapy. The aim of the present study was to examine the effect of hypoxia on gene expression and the changes that occur in relation to drug resistance in a human NSCLC cell line (A549). A549 cells were exposed to 72-h hypoxic episodes (<1% oxygen) for a total of 10 episodes (acute). The alterations in gene expression were examined using PCR array technology after 10 episodes of acute hypoxia and compared with normoxic cells. The chemoresistance of hypoxic cells toward doxorubicin was measured using a MTT cell proliferation assay. A549 cells were affected by acute hypoxia leading to induced doxorubicin chemoresistance. Evident changes in the gene expression level were identified following episodes of acute hypoxia. The most important changes occurred in the estrogen receptor 1 (ESR1) and Finkel-Biskis-Jinkins osteosarcoma (FOS) pathways and in different nucleic transcription factors such as aryl hydrocarbon receptor and cyclin-dependent kinase inhibitor. The present study showed that exposing cells to prolonged periods of hypoxia results in different gene expression changes. There was induction of chemo-resistance due to acute hypoxia. ESR1 and c-FOS are proposed as a potential hypoxia genes in lung cancer.

Cell blebbing novel therapeutic possibilities to counter metastasis

Cells constantly reshape there plasma membrane and cytoskeleton during physiological and pathological processes (Hagmann et al. in J Cell Biochem 73:488-499, 1999). Cell blebbing, the formation of bulges or protrusions on the cell membrane, is related to mechanical stress, changes in intracellular pressure, chemical signals, or genetic anomalies. These membrane bulges interfere with the force balance of actin filaments, microtubules, and intermediate filaments, the basic components of the cytoskeleton (Charras in J Microsc 231:466-478, 2008). In the past, these blebs with circular structures were considered apoptotic markers (Blaser et al. in Dev Cell 11:613-627, 2006). Cell blebbing activates phagocytes and promotes the rapid removal of intrinsic compartments. However, recent studies have revealed that blebbing is associated with dynamic cell reorganization and alters the movement of cells in-vivo and in-vitro (Charras and Paluch in Nat Rev Mol Cell Biol 9:730-736, 2008). During tumor progression, blebbing promotes invasion of cancer cells into blood, and lymphatic vessels, facilitating tumor progression and metastasis (Weems et al. in Nature 615:517-525, 2023). Blebbing is a dominant feature of tumor cells generally absent in normal cells. Restricting tumor blebbing reduces anoikis resistance (survival in suspension) (Weems et al. in Nature 615:517-525, 2023). Hence, therapeutic intervention with targeting blebbing could be highly selective for proliferating pro-metastatic tumor cells, providing a novel therapeutic pathway for tumor metastasis with minimal side effects. Here, we review the association between cell blebbing and tumor cells, to uncover new research directions and strategies for metastatic cancer therapy. Finaly, we aim to identify the druggable targets of metastatic cancer in relation to cell blebbing.

Spatial transcriptomics in breast cancer reveals tumour microenvironment-driven drug responses and clonal therapeutic heterogeneity

Breast cancer patients are categorized into three subtypes with distinct treatment approaches. Precision oncology has increased patient outcomes by targeting the specific molecular alterations of tumours, yet challenges remain. Treatment failure persists due to the coexistence of several malignant subpopulations with different drug sensitivities within the same tumour, a phenomenon known as intratumour heterogeneity (ITH). This heterogeneity has been extensively studied from a tumour-centric view, but recent insights underscore the role of the tumour microenvironment in treatment response. Our research utilizes spatial transcriptomics data from breast cancer patients to predict drug sensitivity. We observe diverse response patterns across tumour, interphase and microenvironment regions, unveiling a sensitivity and functional gradient from the tumour core to the periphery. Moreover, we find tumour therapeutic clusters with different drug responses associated with distinct biological functions driven by unique ligand-receptor interactions. Importantly, we identify genetically identical subclones with different responses depending on their location within the tumour ducts. This research underscores the significance of considering the distance from the tumour core and microenvironment composition when identifying suitable treatments to target ITH. Our findings provide critical insights into optimizing therapeutic strategies, highlighting the necessity of a comprehensive understanding of tumour biology for effective cancer treatment.

[Highlights of the 2024 ASCO Annual Meeting: radiotherapy of head and neck cancer]

At the 2024 Annual Meeting of the American Society of Clinical Oncology (ASCO), several important studies on radiotherapy for head and neck squamous cell carcinoma (HNSCC) were presented. There were two Chinese phase III trials on treatment escalation for locally advanced nasopharyngeal carcinoma: adjuvant immune checkpoint inhibition with camrelizumab after induction chemotherapy and cisplatin-based chemoradiotherapy (RCT) in the DIPPER trial reached the primary endpoint of improved event-free survival (EFS) but did not improve overall survival (OS). Simultaneous and adjuvant administration of the angiogenesis inhibitor endostar in addition to cisplatin-based RCT for locally advanced nasopharyngeal carcinoma led to a significant improvement in progression-free survival (PFS) and OS. Another major focus was on treatment optimization and deintensification for oropharyngeal cancer (OPC): using intensity-modulated proton therapy (IMPT), a phase III trial demonstrated noninferiority in definitive RCT for OPC compared to photon-based intensity-modulated radiotherapy (IMRT). In adjuvant treatment of human papillomavirus-positive (HPV+) OPC, the long-term results of the E3311 phase II study confirmed that individually deintensified radiotherapy is feasible. Lee et al. showed with the results of a phase II study that HPV+ OPC might be treatable with chemoradiotherapy to a total dose of only 30 Gy if no hypoxia is detected in the 18F‑fluoromisonidazole positron-emission tomography-computed tomography (F-MISO-PET) scan. Both the deintensified treatment of HPV+ OPC as well as additive immune checkpoint and angiogenesis inhibition in chemoradiotherapy of nasopharyngeal carcinoma require further studies before they can be recommended in clinical practice.

Progress of research on γδ T cells in colorectal cancer (Review)

Colorectal cancer (CRC) ranks as the third most prevalent malignancy and second leading cause of cancer‑related fatalities worldwide. Immunotherapy alone or in combination with chemotherapy has a favorable survival benefit for patients with CRC. Unlike αβ T cells, which are prone to drug resistance, γδ T cells do not exhibit major histocompatibility complex restriction and can target tumor cells through diverse mechanisms. Recent research has demonstrated the widespread involvement of Vδ1T, Vδ2T, and γδ T17 cells in tumorigenesis and progression. In the present review, the influence of different factors, including immune checkpoint molecules, the tumor microenvironment and microorganisms, was summarized on the antitumor/protumor effects of these cells, aiming to provide insights for the development of more efficient and less toxic immunotherapy‑based anticancer drugs.

Impact of Metabolites from Foodborne Pathogens on Cancer

Foodborne pathogens are microorganisms that cause illness through contamination, presenting significant risks to public health and food safety. This review explores the metabolites produced by these pathogens, including toxins and secondary metabolites, and their implications for human health, particularly concerning cancer risk. We examine various pathogens such as Salmonella sp., Campylobacter sp., Escherichia coli, and Listeria monocytogenes, detailing the specific metabolites of concern and their carcinogenic mechanisms. This study discusses analytical techniques for detecting these metabolites, such as chromatography, spectrometry, and immunoassays, along with the challenges associated with their detection. This study covers effective control strategies, including food processing techniques, sanitation practices, regulatory measures, and emerging technologies in pathogen control. This manuscript considers the broader public health implications of pathogen metabolites, highlighting the importance of robust health policies, public awareness, and education. This review identifies research gaps and innovative approaches, recommending advancements in detection methods, preventive strategies, and policy improvements to better manage the risks associated with foodborne pathogens and their metabolites.

Artificial blood-hope and the challenges to combat tumor hypoxia for anti-cancer therapy

The blood plays a vital role in the human body and serves as an intermediary between various physiological systems and organs. White blood cells, which are a part of the immune system, defend against infections and regulate the body temperature and pH balance. Blood platelets play a crucial role in clotting, the prevention of excessive bleeding, and the promotion of healing. Blood also serves as a courier system that transports hormones to facilitate communication and synchronization between different organs and systems in the body. The circulatory system, comprised of arteries, veins, and capillaries, plays a crucial role in the efficient transportation and connection of vital nutrients and oxygen. Despite the importance of natural blood, there are often supply shortages, compatibility issues, and medical conditions, which make alternatives such as artificial blood necessary. This is particularly relevant in cancer treatment, which was the focus of our study. In this study, we investigated the potential of artificial blood in cancer therapy, specifically to address tumor hypoxia. We also examined the potential of red blood cell substitutes such as hemoglobin-based oxygen carriers and perfluorocarbons. Additionally, we examined the production of hemoglobin using E. coli and the role of hemoglobin in oncogenesis. Furthermore, we explored the potential use of artificial platelets for cancer treatment. Our study emphasizes the significance of artificial blood in improving cancer treatment outcomes.

TMBIM6/BI-1 is an intracellular environmental regulator that induces paraptosis in cancer via ROS and Calcium-activated ERAD II pathways

Transmembrane B cell lymphoma 2-associated X protein inhibitor motif-containing (TMBIM) 6, also known as Bax Inhibitor-1 (BI-1), has been heavily researched for its cytoprotective functions. TMBIM6 functional diversity includes modulating cell survival, stress, metabolism, cytoskeletal dynamics, organelle function, regulating cytosolic acidification, calcium, and reactive oxygen species (ROS). Clinical research shows TMBIM6 plays a key role in many of the world's top diseases/injuries (i.e., Alzheimer's, Parkinson's, diabetes, obesity, brain injury, liver disease, heart disease, aging, etc.), including cancer, where TMBIM6 expression impacts patient survival, chemoresistance, cancer progression, and metastasis. We show TMBIM6 is activated by, and undergoes, different conformational changes that dictate its function following a significant change in the cell's IntraCellular Environment (ICE). TMBIM6 agonism, following ICE change, can help the cell overcome multiple stresses including toxin exposure, viral infection, wound healing, and excitotoxicity. However, in cancer cells TMBIM6 agonism results in rapid paraptotic induction irrespective of the cancer type, sub-type, genotype or phenotype. Furthermore, the level of TMBIM6 expression in cancer did not dictate the level of paraptotic induction; however, it did dictate the rate at which paraptosis occurred. TMBIM6 agonism did not induce paraptosis in cancer via canonical routes involving p38 MAPK, JNK, ERK, UPR, autophagy, proteasomes, or Caspase-9. Instead, TMBIM6 agonism in cancer upregulates cytosolic Ca2+ and ROS, activates lysosome biogenesis, and induces paraptosis via ERAD II mechanisms. In xenograft models, we show TMBIM6 agonism induces rapid cancer cell death with no toxicity, even at high doses of TMBIM6 agonist (>450 mg/kg). In summary, this study shows TMBIM6's functional diversity is only activated by severe ICE change in diseased/injured cells, highlighting its transformative potential as a therapeutic target across various diseases and injuries, including cancer.

The Hippo Pathway in Breast Cancer: The Extracellular Matrix and Hypoxia

As one of the most prevalent malignant neoplasms among women globally, the optimization of therapeutic strategies for breast cancer has perpetually been a research hotspot. The tumor microenvironment (TME) is of paramount importance in the progression of breast cancer, among which the extracellular matrix (ECM) and hypoxia are two crucial factors. The alterations of these two factors are predominantly regulated by the Hippo signaling pathway, which promotes tumor invasiveness, metastasis, therapeutic resistance, and susceptibility. Hence, this review focuses on the Hippo pathway in breast cancer, specifically, how the ECM and hypoxia impact the biological traits and therapeutic responses of breast cancer. Moreover, the role of miRNAs in modulating ECM constituents was investigated, and hsa-miR-33b-3p was identified as a potential therapeutic target for breast cancer. The review provides theoretical foundations and potential therapeutic direction for clinical treatment strategies in breast cancer, with the aspiration of attaining more precise and effective treatment alternatives in the future.

Understanding Metabolic Pathway Rewiring by Oncogenic Gamma Herpesvirus

Gamma herpesviruses, including Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV), are key contributors to the development of various cancers through their ability to manipulate host cellular pathways. This review explores the intricate ways these viruses rewire host metabolic pathways to sustain viral persistence and promote tumorigenesis. We look into how EBV and KSHV induce glycolytic reprogramming, alter mitochondrial function, and remodel nucleotide and amino acid metabolism, highlighting the crucial role of lipid metabolism in these oncogenic processes. By understanding these metabolic alterations, which confer proliferative and survival advantages to the virus-infected cells, we can identify potential therapeutic targets and develop innovative treatment strategies for gamma herpesvirus-associated malignancies. Ultimately, this review underscores the critical role of metabolic reprogramming in gamma herpesvirus oncogenesis and its implications for precision medicine in combating virus-driven cancers.

Morphological and Molecular-Biological Features of Lewis Lung Carcinoma Progression in Mice with Different Resistance to Hypoxia

In adult male mice with high (HR) and low (LR) resistance to hypoxia, on days 21 and 28 after subcutaneous injection of Lewis lung carcinoma cells, a morphological and morphometric study of the primary tumor nodes and metastases in the lungs was carried out. Peripheral blood parameters and subpopulation composition of blood cells, the expression of genes responsible for the development of inflammation (Nfkb, Il1b, Il6, Tnfa, Il10, and Tgfb) and the response to hypoxia (Hif1a) in the liver were also assessed. The tumors were detected in 84.6% HR and 91.7% LR mice. The mitotic index of tumor cells in the subcutaneous nodes of HR animals was statistically significantly higher. The metastases area on days 21 and 28 did not differ. In animals of both groups, an increase in the absolute number of leukocytes, monocytes, and granulocytes, a decrease in the hemoglobin content and the absolute number of erythrocytes in the peripheral blood were detected on day 28 of the experiment. Only in LR animals, an increase in the absolute number of CD11b+ monocytes was found on day 28 of the experiment in comparison with the control group. The expression of Hif1a, Nfkb, Tnfa, and Tgfb genes in the liver of LR animals was higher than in HR mice, which attested to more pronounced systemic inflammatory response. These data should be taken into account when developing new approaches for the treatment of neoplastic disorders.

Cellular MSI-H score: a robust predictive biomarker for immunotherapy response and survival in gastrointestinal cancer

Microsatellite instability-high (MSI-H) is a critical biomarker for immunotherapy, yet primary resistance remains a significant challenge. Current MSI-H detection methods evaluate the proportion of MSI-H loci, termed molecular MSI-H score, which can be affected by intratumoral heterogeneity (ITH). To address this limitation, we propose evaluating MSI-H at the cellular level to improve the prediction of immunotherapy outcomes. Using bulk tissue (TCGA-CRC) and cell line (CCLE-CRC) datasets, we identified genes highly expressed in MSI-H and MSS samples. These signatures were applied to a single-cell RNA sequencing (scCRC) dataset for enrichment analysis, enabling classification of tumor cells into MSI-H, MSS, and microsatellite dual (MSD) clusters using a Gaussian finite mixture model. Validation showed that MSI-H and MSS enrichment scores were higher in mismatch repair-deficient (MMRd) and mismatch repair-proficient (MMRp) patients, respectively. Functional enrichment analysis revealed that MSI-H cells were associated with pathways such as carboxylic acid catabolism, inflammatory responses, and IL-6/JAK2/STAT3 signaling. We developed a cellular MSI-H signature using genes specifically expressed in the MSI-H cell cluster and transformed the scCRC dataset into a cell-type-specific pseudobulk expression matrix. Using this matrix as a reference, we performed reference-based deconvolution on TCGA-CRC data. We defined the deconvolution score of MSI-H cell as cellular MSI-H score. This score strongly correlated with the molecular MSI-H score (R = 0.55, P < 0.001) and showed modest correlations with macrophage (MoMac, R = 0.14) and CD8+ T-cell (R = 0.11). To investigate its potential for clinical application, we applied the cellular MSI-H signature to the BJ-cohort, comprising 97 immunotherapy-treated gastrointestinal patients sequenced with a 395-gene panel. The cellular MSI-H score was significantly higher in responders (P = 0.002), positively correlated with tumor reduction percentage (R = 0.29, P = 0.006), and associated with improved progression-free survival (PFS) (HR: 0.00, 95% CI: 0.00-0.31, P = 0.021). In summary, the cellular MSI-H score reflects the MSI-H cell level within a tumor and demonstrates superior accuracy compared to molecular MSI-H status in predicting immunotherapy response and PFS. This underscores its potential as a more robust biomarker for guiding immunotherapy decisions.

Inhibitory effects of circR-127aa on gastric cancer progression and tumor growth

This study investigates the function of a newly identified 127-amino acid peptide, circR-127aa, encoded by hsa_circ_0075402 (circRACK1), in gastric cancer (GC), a condition with significant prevalence in China. Utilizing a comprehensive analysis of circular RNA (circRNA) ribosome profiling data alongside experimental validations through mass spectrometry, Western blot, and immunofluorescence, we demonstrate that circR-127aa Inhibits Malignant Phenotypes and suppresses tumor growth in nude mice models. Significantly, the interaction of circR-127aa with Vimentin, a crucial element in actin-actin-cytoskeletal remodeling, indicates that circR-127aa functions as a tumor suppressor by facilitating the ubiquitination of Vimentin. These findings advance our comprehension of gastric cancer (GC) progression and propose circR-127aa as a promising therapeutic target and biomarker in the management of GC.

Metabolic reprogramming and therapeutic resistance in primary and metastatic breast cancer

Metabolic alterations, a hallmark of cancer, enable tumor cells to adapt to their environment by modulating glucose, lipid, and amino acid metabolism, which fuels rapid growth and contributes to treatment resistance. In primary breast cancer, metabolic shifts such as the Warburg effect and enhanced lipid synthesis are closely linked to chemotherapy failure. Similarly, metastatic lesions often display distinct metabolic profiles that not only sustain tumor growth but also confer resistance to targeted therapies and immunotherapies. The review emphasizes two major aspects: the mechanisms driving metabolic resistance in both primary and metastatic breast cancer, and how the unique metabolic environments in metastatic sites further complicate treatment. By targeting distinct metabolic vulnerabilities at both the primary and metastatic stages, new strategies could improve the efficacy of existing therapies and provide better outcomes for breast cancer patients.

Small Molecule RNA Degraders

RNA is a central molecule in life, involved in a plethora of biological processes and playing a key role in many diseases. Targeting RNA emerges as a significant endeavor in drug discovery, diverging from conventional protein-centric approaches to tackle various pathologies. Whilst identifying small molecules that bind to specific RNA regions is the first step, the abundance of non-functional RNA segments renders many interactions biologically inert. Consequently, small molecule binding does not necessarily meet stringent criteria for clinical translation, calling for solutions to push the field forward. Converting RNA-binders into RNA-degraders presents a promising avenue to enhance RNA-targeting. This mini-review outlines strategies and exemplars wherein simple small molecule RNA binders are reprogrammed into active degraders through the linkage of functional groups. These approaches encompass mechanisms that induce degradation via endogenous enzymes, termed RIBOTACs, as well as those with functional moieties acting autonomously to degrade RNA. Through this exploration, we aim to offer insights into advancing RNA-targeted therapeutic strategies.

ATP6V1C1, associated with the tumor microenvironment and mTORC1 signaling pathway, is a potential diagnostic, prognostic, and therapeutic biomarker for hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a global health challenge with high mortality. ATP6V1C1, one of the subunit genes of vacuolar adenosine triphosphatase (V-ATPase), is a potential oncogene. However, its role in HCC remains unclear.

MATERIALS AND METHODS

Differential analysis of mRNA and microRNA (miRNA), combined with machine learning, identified ATP6V1C1 as a potential biomarker for HCC. The expression and prognostic role of ATP6V1C1 in HCC were evaluated. Additionally, we explored the distribution of ATP6V1C1 in HCC tumor microenvironment (TME) at single-cell and spatial transcriptome levels. Furthermore, the association between ATP6V1C1 and malignant biological features, TME characteristics, and therapy response in HCC was investigated. Finally, in vitro experiments validated the effects of ATP6V1C1 on the malignant phenotype of HCC.

RESULTS

ATP6V1C1 had higher expression in HCC tissues compared to paired normal tissues. Upregulated ATP6V1C1 was associated with poor HCC prognosis. ATP6V1C1 was primarily expressed in malignant cells and the tumor region in HCC TME. A positive correlation was observed between ATP6V1C1 expression and the activation of cancer-related pathways. The high ATP6V1C1 expression group exhibited increased pro-tumorigenic immune infiltration, inhibited anti-tumor immune activity, and high tumor proliferation rate. HCC patients of low ATP6V1C1 expression group had more clinical response to anti-tumor therapies. Knockdown of ATP6V1C1 impaired the proliferation, migration, and invasion of HCC cells by downregulating the mTORC1 signaling pathway.

CONCLUSION

ATP6V1C1 multifacetedly contributes to the oncogenesis and progression of HCC and is a promising diagnostic and prognostic biomarker with predictive value on therapy response.

Multi-omics-driven discovery of invasive patterns and treatment strategies in CA19-9 positive intrahepatic cholangiocarcinoma

BACKGROUND

Intrahepatic cholangiocarcinoma (ICC) is a malignant tumor with a poor prognosis, predominantly CA19-9 positive. High CA19-9 levels correlate with increased aggressiveness and worse outcomes. This study employs multi-omics analysis to reveal molecular features and identify therapeutic targets of CA19-9 positive ICC, aiming to support individualized treatment.

METHODS

Data from seven clinical cohorts, two whole-exome sequencing cohorts, six RNA sequencing/microarray cohorts, one proteomic cohort, 20 single-cell RNA sequencing samples, and one spatial transcriptome sample were analyzed. Key findings were validated on tissue microarrays from 52 ICC samples.

RESULTS

CA19-9 positive ICC exhibited poorer OS (median 24.1 v.s. 51.5 months) and RFS (median 11.7 v.s. 28.2 months) compared to negative group (all P < 0.05). Genomic analysis revealed a higher KRAS mutation frequency in the positive group and a greater prevalence of IDH1/2 mutations in the negative group (all P < 0.05). Transcriptomic analysis indicated upregulated glycolysis pathways in CA19-9 positive ICC. Single-cell analysis identified specific glycolysis-related cell subclusters associated with poor prognosis, including Epi_SLC2A1, CAF_VEGFA, and Mph_SPP1. Higher hypoxia in the CA19-9 positive group led to metabolic reprogramming and promoted these cells' formation. These cells formed interactive communities promoting epithelial-mesenchymal transition (EMT) and angiogenesis. Drug sensitivity analysis identified six potential therapeutic drugs.

CONCLUSIONS

This study systematically elucidated the clinical, genomic, transcriptomic, and immune features of CA19-9 positive ICC. It reveals glycolysis-associated cellular communities and their cancer-promoting mechanisms, enhancing our understanding of ICC and laying the groundwork for individualized therapeutic strategies.

Integrated analysis of single-cell and bulk transcriptome reveals hypoxia-induced immunosuppressive microenvironment to predict immunotherapy response in high-grade serous ovarian cancer

Background

Hypoxia is significantly associated with cancer progression and treatment outcomes. Nevertheless, the precise molecular mechanisms underlying the hypoxia-induced immunosuppressive microenvironment in high-grade serous ovarian cancer (HGSOC) are still not fully understood.

Methods

By analyzing five independent transcriptomic datasets, we investigated the effect of hypoxia on prognosis and tumor microenvironment (TME) in HGSOC. The hypoxia levels and the intercellular communication signaling pathways were studied by using single-cell analysis. Furthermore, the Hypoxia-TME classifier was developed and then validated in the multiple HGSOC datasets. In addition, we also investigated the prognostic significance, genetic variations, signaling pathways, and the potential for immunotherapy benefits in different Hypoxia-TME subgroups.

Results

Hypoxia was identified as a crucial risk factor in HGSOC, and strongly correlated with an immunosuppressive microenvironment characterized by alterations in the composition and distribution of immune cells. Single-cell analysis elucidated the heterogeneity inherent within the TME in HGSOC, and demonstrated an association between the hypoxic TME and fibroblasts as well as macrophages. CellChat analysis identified SPP1-CD44 and CXCL12-CXCR4 as the principal signaling axes through which macrophages and fibroblasts interact with T cells, respectively. Moreover, a personalized Hypoxia-TME classifier was constructed and validated through the integration of the hypoxia (18 genes) and TME (7 immune cells) scores. It was observed that patients in the Hypoxialow/TMEhigh subgroup displayed a significantly better prognosis than other subgroups. Different subgroups exhibited unique genomic alterations and variations in signaling pathway differences, including TGF-β and Wnt/β-catenin pathways, which are closely associated with various biological functions. Finally, our results indicated that patients in the Hypoxialow/TMEhigh subgroup exhibit a better response to immunotherapy, suggesting the potential utility of the Hypoxia-TME classifier as a new biomarker in HGSOC.

Conclusion

Our study revealed hypoxia-induced immunosuppressive microenvironment, and developed Hypoxia-TME classifier to distinguish the prognosis, immune characteristics, and potential benefits of immunotherapy in HGSOC.

Harnessing Bacterial Agents to Modulate the Tumor Microenvironment and Enhance Cancer Immunotherapy

Cancer immunotherapy has revolutionized cancer treatment by leveraging the immune system to attack tumors. However, its effectiveness is often hindered by the immunosuppressive tumor microenvironment (TME), where a complex interplay of tumor, stromal, and immune cells undermines antitumor responses and allows tumors to evade immune detection. This review explores innovative strategies to modify the TME and enhance immunotherapy outcomes, focusing on the therapeutic potential of engineered bacteria. These bacteria exploit the unique characteristics of the TME, such as abnormal vasculature and immune suppression, to selectively accumulate in tumors. Genetically modified bacteria can deliver therapeutic agents, including immune checkpoint inhibitors and cytokines, directly to tumor sites. This review highlights how bacterial therapeutics can target critical immune cells within the TME, such as myeloid-derived suppressor cells and tumor-associated macrophages, thereby promoting antitumor immunity. The combination of bacterial therapies with immune checkpoint inhibitors or adoptive cell transfer presents a promising strategy to counteract immune suppression. Continued research in this area could position bacterial agents as a powerful new modality to reshape the TME and enhance the efficacy of cancer immunotherapy, particularly for tumors resistant to conventional treatments.

Developing hypoxia and lactate metabolism-related molecular subtypes and prognostic signature for clear cell renal cell carcinoma through integrating machine learning

BACKGROUND

The microenvironment of clear cell renal cell carcinoma (ccRCC) is characterized by hypoxia and increased lactate production. However, the impact of hypoxia and lactate metabolism on ccRCC remains incompletely understood. In this study, a new molecular subtype is developed based on hypoxia-related genes (HRGs) and lactate metabolism-related genes (LMRGs), aiming to create a tool that can predict the survival rate, immune microenvironment status, and responsiveness to treatment of ccRCC patients.

METHOD

We obtained RNA-seq data and clinical information of patients with ccRCC from TCGA and GEO. HRGs and LMRGs are sourced from the Molecular Signatures Database. Integrating 10 machine learning algorithms and 101 frameworks, we constructed a prognostic model related to hypoxia and lactate metabolism. Its accuracy and reliability are evaluated through constructing prognostic nomograms, drawing ROC curves, and validating with clinical datasets. Additionally, risk subgroups are evaluated based on functional enrichment, tumor mutational burden (TMB), immune cell infiltration degree, and immune checkpoint expression level. Finally, we evaluate the responsiveness of risk subgroups to immunotherapy and determine personalized drugs for specific risk subgroups.

RESULTS

85 valuable prognostic genes were screened out. Functional enrichment analysis shows that the group with high-risk hypoxia and lactate metabolism-related genes scores (HLMRGS) is mainly involved in the activation of immune-related activities, while the low risk HLMRGS group is more active in metabolic and tumor-related pathways. At the same time, differences in the cellular functional states in the tumor microenvironment between the high risk HLMRGS group and the low risk HLMRGS group were observed. Finally, potential drugs for specific risk subgroups were determined.

CONCLUSION

We have developed a novel prognostic signature that integrates hypoxia and lactate metabolism. It is expected to become an effective tool for prognosis prediction, immunotherapy and personalized medicine of ccRCC.

Logic-gated and contextual control of immunotherapy for solid tumors: contrasting multi-specific T cell engagers and CAR-T cell therapies

CAR-T cell and T cell engager therapies have demonstrated transformational efficacy against hematological malignancies, but achieving efficacy in solid tumors has been more challenging, in large part because of on-target/off-tumor toxicities and sub-optimal T cell anti-tumor cytotoxic functions. Here, we discuss engineering solutions that exploit biological properties of solid tumors to overcome these challenges. Using logic gates as a framework, we categorize the numerous approaches that leverage two inputs instead of one to achieve better cancer selectivity or efficacy in solid tumors with dual-input CAR-Ts or multi-specific TCEs. In addition to the "OR gate" and "AND gate" approaches that leverage dual tumor antigen targeting, we also review "contextual AND gate" technologies whereby continuous cancer-selective inputs such a pH, hypoxia, target density, tumor proteases, and immune-suppressive cytokine gradients can be creatively incorporated in therapy designs. We also introduce the notion of "output directionality" to distinguish dual-input strategies that mechanistically impact cancer cell killing or T cell fitness. Finally, we contrast the feasibility and potential benefits of the various approaches using CAR-T and TCE therapeutics and discuss why the promising "IF/THEN" and "NOT" gate types pertain more specifically to CAR-T therapies, but can also succeed by integrating both technologies.

Stemness of Cancer: A Study of Triple-negative Breast Cancer From a Neuroscience Perspective

Stemness, giving cancer cells massive plasticity enabling them to survive in dynamic (e.g. hypoxic) environments and become resistant to treatment, especially chemotherapy, is an important property of aggressive tumours. Here, we review some essentials of cancer stemness focusing on triple-negative breast cancer (TNBC), the most aggressive form of all breast cancers. TNBC cells express a range of genes and mechanisms associated with stemness, including the fundamental four "Yamanaka factors". Most of the evidence concerns the transcription factor / oncogene c-Myc and an interesting case is the expression of the neonatal splice variant of voltage-gated sodium channel subtype Nav1.5. On the whole, measures that reduce the stemness make cancer cells less aggressive, reducing their invasive/metastatic potential and increasing/restoring their chemosensitivity. Such measures include gene silencing techniques, epigenetic therapies as well as novel approaches like optogenetics aiming to modulate the plasma membrane voltage. Indeed, simply hyperpolarizing their membrane potential can make stem cells differentiate. Finally, we give an overview of the clinical aspects and exploitation of cancer/TNBC stemness, including diagnostics and therapeutics. In particular, personalised mRNA-based therapies and mechanistically meaningful combinations are promising and the emerging discipline of 'cancer neuroscience' is providing novel insights to both fundamental issues and clinical applications.