Mutant p53 cancers reprogram macrophages to tumor supporting macrophages via exosomal miR-1246

Exosome-mediated ferroptosis in the tumor microenvironment: from molecular mechanisms to clinical application

Ferroptosis in the tumor microenvironment (TME) plays a crucial role in the development, metastasis, immune escape, and drug resistance of various types of cancer. A better understanding of ferroptosis in the TME could illuminate novel aspects of this process and promote the development of targeted therapies. Compelling evidence indicates that exosomes are key mediators in regulating the TME. In this respect, it is now understood that exosomes can deliver biologically functional molecules to recipient cells, influencing cancer progression by reprogramming the metabolism of cancer cells and their surrounding stromal cells through ferroptosis. In this review, we focus on the role of exosomes in the TME and describe how they contribute to tumor reprogramming, immunosuppression, and the formation of pre-metastatic niches through ferroptosis. In addition, we highlight exosome-mediated ferroptosis as a potential target for cancer therapy and discuss strategies employing exosomes in ferroptosis treatment. Finally, we outline the current applications and challenges of targeted exosome-mediated ferroptosis therapy in tumor immunotherapy and chemotherapy. Our aim is to advance research on the link between exosomes and ferroptosis in the TME, and we pose questions to guide future studies in this area.

Crosstalk between exosomes and tumor-associated macrophages in hepatocellular carcinoma: implication for cancer progression and therapy

Hepatocellular carcinoma (HCC), the most prevalent type of primary liver cancer, represents a significant cause of cancer-related mortality. While our understanding of its pathogenesis is comparatively comprehensive, the influence of the tumor microenvironment (TME) on its progression warrants additional investigation. Tumor-associated macrophages (TAMs) have significant impacts on cancer cell proliferation, migration, invasion, and immune response, facilitating a complex interaction within the TME. Exosomes, which measure between 30 and 150 nanometers in size, are categorized into small extracellular vesicles, secreted by a wide range of eukaryotic cells. They can transfer biological molecules including proteins, non-coding RNAs, and lipids, which mediates the intercellular communication within the TME. Emerging evidence has revealed that exosomes regulate macrophage polarization, thus impacting cancer progression and immune responses within the TME of HCC. Moreover, TAM-derived exosomes also play crucial roles in malignant transformation, which hold immense potential for cancer therapy. In this review, we elaborate on the crosstalk between exosomes and TAMs within TME during HCC development. Moreover, we delve into the feasible treatment approaches for exosomes in cancer therapy and emphasize the limitations and challenges for the translation of exosomes derived from TAMs into clinical courses for cancer therapy, which may provide new perspectives on further ameliorations of therapeutic regimes based on exosomes to advance their clinical applications.

p53: A player in the tumor microenvironment

Approximately half of all cancers have p53 inactivating mutations, in addition to which most malignancies inactivate the p53 pathway by increasing p53 inhibitors, decreasing p53 activators, or inactivating p53 downstream targets. A growing number of researches have demonstrated that p53 can influence tumor progression through the tumor microenvironment (TME). TME is involved in the process of tumor development and metastasis and affects the clinical prognosis of patients. p53 participates in host immunity and engages in the immune landscape of the TME, but the specific mechanisms remain to be investigated. This review briefly explores the interactions between different states of p53 and TME components and their mechanisms, as well as their effects on tumor progression. To understand the progress of drug development and clinical studies related to p53 and tumor microenvironment.

Inflammation and cancer: molecular mechanisms and clinical consequences

Inflammation, a hallmark of cancer, has been associated with tumor progression, transition into malignant phenotype and efficacy of anticancer treatments in cancer. It affects all stages of cancer, from the initiation of carcinogenesis to metastasis. Chronic inflammation induces immunosup-pression, providing an environment conducive to carcinogenesis, whereas acute inflammation induces an antitumor immune response, leading to tumor suppression. Solid tumors have an inflammatory tumor microenvironment (TME) containing cancer cells, immune cells, stromal cells, and soluble molecules, which plays a key role in tumor progression and therapy response. Both cancer cells and stromal cells in the TME are highly plastic and constantly change their phenotypic and functional properties. Cancer-associated inflammation, the majority of which consists of innate immune cells, plays an important role in cancer cell plasticity, cancer progression and the development of anticancer drug resistance. Today, with the combined used of advanced technologies, such as single-cell RNA sequencing and spatial molecular imaging analysis, the pathways linking chronic inflammation to cancer have been largely elucidated. In this review article, we highlighted the molecular and cellular mechanisms involved in cancer-associated inflammation and its effects on cancer progression and treatment response. We also comprehensively review the mechanisms linking chronic inflammation to cancer in the setting of GI cancers.

Role of exosomal miRNAs and macrophage polarization in gastric cancer: A novel therapeutic strategy

Gastric cancer (GC) is one of the most common gastrointestinal cancers worldwide, with consistently high morbidity and mortality rates and poor prognosis. Most patients are diagnosed at an advanced stage due to the lack of specific presentation in the early stages. Exosomes are a class of extracellular vesicles (EVs) widely found in body fluids and can release genetic material or multiple proteins to facilitate intercellular communication. In recent years, exosomal miRNAs have gained attention for their role in various cancers. These exosomal miRNAs can impact GC development and progression by targeting specific genes or influencing signaling pathways and cytokines involved in Angiogenesis, epithelial-mesenchymal transition (EMT), drug resistance, and immune regulation. They show great potential in terms of diagnosis, prognosis, and treatment of GC. Notably, the gastrointestinal tract has the largest number of macrophages, which play a significant role in GC progression. Tumor-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment (TME) and can influence macrophage programming through various mediators, including macrophage polarization. Macrophage polarization is involved in inflammatory responses and significantly impacts the GC process.

Tumor suppressor genes in the tumor microenvironment

Tumor suppressor genes (TSGs) are thought to suppress tumor development primarily via cancer cell-autonomous mechanisms. However, the tumor microenvironment (TME) also significantly influences tumorigenesis. In this context, a role for TSGs in the various cell types of the TME in regulating tumor growth is emerging. Indeed, expression analyses of TSGs in clinical samples, along with data from mouse models in which TSGs were deleted selectively in the TME, indicate a functional role for them in tumor development. In this Perspective, using TP53 and PTEN as examples, we posit that TSGs play a significant role in cells of the TME in regulating tumor development, and postulate both a 'pro-active' and 'reactive' model for their contribution to tumor growth, dependent on the temporal sequence of initiating events. Finally, we discuss the need to consider a 2-in-1 cancer-treatment strategy to improve the efficacy of clearance of cancer cells and the cancer-promoting TME.

Cancer-secreted exosomal miR-1246 promotes colorectal cancer liver metastasis by activating hepatic stellate cells

Colorectal cancer liver metastases (CRLM) are the primary cause of mortality in colorectal cancer (CRC) patients, highlighting the importance of understanding the underlying mechanisms. The tumor microenvironment (TME) and its interaction with tumor cells play a crucial role in CRLM progression. Notably, the stability and peak levels of tumor-derived exosomal miRNAs facilitate intercellular communication in the TME. Hepatic stellate cells (HSCs), key liver mesenchymal cells, constitute about 33% of the liver's nonsolid cell population and exhibit plasticity. However, the specific role of tumor-derived exosomal miRNAs in the crosstalk between HSCs and tumor cells during the CRLM process remains unclear. We studied CRC-secreted exosomal miR-1246 and its impact on HSCs, as well as its effects on CRC cell proliferation and metastasis. Our findings demonstrate that CRC-secreted exosomal miR-1246 can be internalized by HSCs, leading to their activation and facilitating the metastatic potential of CRC cells. Mechanistically, exosomal miR-1246 targets INSIG1, resulting in SREBP2 nucleation and cholesterol metabolism alterations. This accumulation of free cholesterol (FC) regulates the TLR4/NF-κB/TGF-β pathway, promoting HSC activation. Activated HSCs, in turn, enhance liver metastasis of CRC cells through the TNFSF13/TNFRSF13B axis. Our study reveals the role of CRC-secreted exosomal miR-1246 in triggering HSC activation and reprogramming the TME, ultimately facilitating liver metastasis in CRC patients. Exosomal miR-1246 could serve as a potential non-invasive biomarker for predicting colorectal cancer liver metastasis, enhancing our understanding of CRC-associated liver metastases.

TP53 Deficiency in the Natural History of Prostate Cancer

Prostate cancer remains a leading cause of cancer-related mortality in men, with advanced stages posing significant treatment challenges due to high morbidity and mortality. Among genetic alterations, TP53 mutations are among the most prevalent in cancers and are strongly associated with poor clinical outcomes and therapeutic resistance. This review investigates the role of TP53 mutations in prostate cancer progression, prognosis, and therapeutic development. A comprehensive analysis of preclinical and clinical studies was conducted to elucidate the molecular mechanisms, clinical implications, and potential therapeutic approaches associated with TP53 alterations in prostate cancer. TP53 mutations are highly prevalent in advanced stages, contributing to genomic instability, aggressive tumor phenotypes, and resistance to standard treatments. Emerging evidence supports the utility of liquid biopsy techniques, such as circulating tumor DNA analysis, for detecting TP53 mutations, providing prognostic value and facilitating early intervention strategies. Novel therapeutic approaches targeting TP53 have shown promise in preclinical settings, but their clinical efficacy requires further validation. Overall, TP53 mutations represent a critical biomarker for disease progression and therapeutic response in prostate cancer. Advances in detection methods and targeted therapies hold significant potential to improve outcomes for patients with TP53-mutated prostate cancer. Further research is essential to integrate TP53-based strategies into routine clinical practice.

Engineered Immunomodulatory Extracellular Vesicles from Epithelial Cells with the Capacity for Stimulation of Innate and Adaptive Immunity in Cancer and Autoimmunity

Extracellular vesicles (EVs) are generated in all cells. Systemic administration of allogenic EVs derived from epithelial and mesenchymal cells has been shown to be safe, despite carrying an array of functional molecules, including thousands of proteins. To address whether epithelial cell-derived EVs can be modified to acquire the capacity to induce an immune response, we engineered 293T EVs to harbor the immunomodulatory molecules CD80, OX40L, and PD-L1. We demonstrated abundant levels of these proteins in the engineered cells and EVs. Functionally, the engineered EVs efficiently elicited positive and negative costimulation of human and murine T cells. In the setting of cancer and autoimmune hepatitis, the engineered EVs modulated T cell functions and altered disease progression. OX40L EVs also provided enhanced antitumor activity in combination with anti-CTLA-4 in melanoma-bearing mice. In addition, we added multiple immunomodulatory proteins in EVs (EVmIM), attempting to elicit an immune response in both lymphoid and myeloid compartments. The EVmIM containing CD80, 4-1BBL, CD40L, CD2, and CD32 engaged both T cells and antigen presenting cells (APCs) in melanoma tumors, demonstrating the capacity for EVmIM to elicit antitumor activity. Our work provides evidence that EVs can be engineered to induce specific immune responses with translational potential to modulate immune cell functions in pathological settings.

Breathing new insights into the role of mutant p53 in lung cancer

The tumour suppressor gene p53 is one of the most frequently mutated genes in lung cancer and these defects are associated with poor prognosis, albeit some debate exists in the lung cancer field. Despite extensive research, the exact mechanisms by which mutant p53 proteins promote the development and sustained expansion of cancer remain unclear. This review will discuss the cellular responses controlled by p53 that contribute to tumour suppression, p53 mutant lung cancer mouse models and characterisation of p53 mutant lung cancer. Furthermore, we discuss potential approaches of targeting mutant p53 for the treatment of lung cancer.

Improving Outcomes in Hepatocellular Carcinoma through Integration of Machine Learning: Development of a Tumor-Associated Macrophage Signature

INTRODUCTION

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors globally. Macrophages, as essential components of the immune system, play crucial roles in immune regulation, inflammation modulation, and antitumor activity. However, it remains unclear whether tumor-associated macrophages can serve as prognostic markers for HCC.

METHODS

First, we identified tumor-associated macrophages based on single-cell data from GSE140228. Then, using a machine learning approach with a combination of 101 module genes, we constructed an optimal prognostic model. Subsequently, we compared our constructed model with other published prognostic models for HCC. Finally, we utilized the generated model score to predict the response to chemotherapy and immune therapy.

RESULTS

First, we identified clusters of tumor-associated macrophages using single-cell data. Subsequently, we calculated the tumor-associated macrophage score based on module genes from the previous step. Compared to traditional clinical indicators, tumor-associated macrophage signature (TAMS) exhibits significant advantages. The TAMS C-index not only predicts overall survival, but also recurrence-free survival in HCC patients. Additionally, there was a higher prevalence of TP53 mutations in HCC patients with high TAMS. Furthermore, patients with low TAMS showed greater sensitivity to immunotherapy compared to those with high TAMS. Notably, the number and intensity of interactions between TAM and other T lymphocytes were significantly higher than those involving other cell populations. Interestingly, the high TAMS group exhibited significantly elevated levels of immune checkpoint markers and M2 macrophage markers.

CONCLUSION

TAMS can serve as a novel and potent tool, offering improved treatment options and prognostic assessment for patients with HCC.

Exploring Anticitrullinated Antibodies (ACPAs) and Serum-Derived Exosomes Cargoes

BACKGROUND

Autoantibodies such as rheumatoid factor (RF) and anticitrullinated protein autoantibodies (ACPAs) are useful tools for rheumatoid arthritis (RA). The presence of ACPAs against citrullinated proteins (CPs), especially citrullinated fibrinogen (cFBG), seems to be a useful serological marker for diagnosing RA. RA patients' sera were found to be enriched in exosomes that can transmit many proteins. Exosomes have been found to express citrullinated protein such as cFBG.

OBJECTIVE

We conducted this study in two stages. In the first phase, we aimed to evaluate the association between autoantibodies and risk factors. In the next step, ACPA-positive serum samples from the first phase were subjected to exosomal studies to explore the presence of cFBG, which is a frequent target for ACPAs.

METHODS

We investigated the autoantibodies in one hundred and sixteen Saudi RA patients and correlated with host-related risk factors. Exosomes were extracted from patients' sera and examined for the presence of cFBG using monoclonal antibodies.

RESULTS

The study reported a high female-to-male ratio of 8:1, and seropositive RA (SPRA) was more frequent among included RA patients. The frequency and the levels of ACPAs were similar in both genders. Autoantibodies incidences have a direct correlations with patient age, while the average titers decreased as the age increased. Further, the highest incidence and levels of autoantibodies were reported in patients with RA duration between 5 and 10 years. Smoking and family history have no impact on autoantibody, except for ACPAs titers among smokers' RA. Our analysis of serum exosomes revealed that about 50% of SPRA patients expressed cFBG.

CONCLUSIONS

The female-to-male ratio is 8:1, which is higher than the global ratio. We can conclude that patients' age and disease duration contribute to the autoantibodies, particularly RF and anti-MCV, whereas smoking and family history had no effects on autoantibodies. We detected cFBG in all exosomes from SPRA patients; thus, we suggest that the precise mechanism of exosomes in RA pathogenesis can be investigated to develop effective treatment strategies.

Tp53 determines the spatial dynamics of M1/M2 tumor-associated macrophages and M1-driven tumoricidal effects

The spatial role of M1 and M2 tumor-associated macrophages (M1/M2 TAMs) in precision medicine remains unclear. EGFR and TP53 are among the most frequently mutated genes in lung adenocarcinoma. We characterized the mutation status and density of M1/M2 TAMs within tumor islets and stroma in 117 lung adenocarcinomas using next-generation sequencing and immunohistochemistry, respectively. Stromal M1 TAMs were positively correlated with disease progression and smoking history. In contrast, islet M1/M2 TAMs were predominantly found in tumors with wild-type TP53 (wtp53) but not associated with EGFR status. The presence of wtp53 was associated with the spatial distribution of M1/M2 TAMs in tumor islets and stroma. Additionally, dominance of islet M1 TAMs and M1-signature were significantly associated with improved survival in patients with wtp53 lung adenocarcinoma, unlike in those with mutant TP53. Conditioned medium from M1 macrophages (M1 CM) induced apoptosis in wtp53 cells through increased p53 accumulation. We found that interferons in M1 CM activate JAK1/TYK2 via IFNARs, leading to enhanced STAT1 expression and Y701 phosphorylation. This activation facilitates p53-STAT1 interactions, reduces the interaction between p53 and MDM2, and subsequently decreases p53 ubiquitination. M1 CM inhibited tumorigenesis, and silencing p53 reduced the anti-tumor efficacy of polyinosinic:polycytidylic acid (poly I:C) in vivo. Furthermore, higher M1-signature was significantly associated with better responses and survival following anti-PD1 treatment in wtp53 melanomas. IFNs/STAT1/p53 signaling was critical for the anti-tumor activity of M1 macrophages. These findings suggest that p53 modulates the spatial balance of M1/M2 TAMs, and the tumoricidal effects of M1 TAMs depend on p53 status. Thus, p53 companion diagnostics could facilitate the development of M1-oriented therapies, which may be particularly beneficial for wtp53 patients when combined with immunotherapy.

Sustained inhibition of CSF1R signaling augments antitumor immunity through inhibiting tumor-associated macrophages

Tumor-associated macrophages (TAMs) are one of the key immunosuppressive components in the tumor microenvironment (TME) and contribute to tumor development, progression, and resistance to cancer immunotherapy. Several reagents targeting TAMs have been tested in preclinical and clinical studies, but they have had limited success. Here, we show that a unique reagent, FF-10101, exhibited a sustained inhibitory effect against colony-stimulating factor 1 receptor by forming a covalent bond and reduced immunosuppressive TAMs in the TME, which led to strong antitumor immunity. In preclinical animal models, FF-10101 treatment significantly reduced immunosuppressive TAMs and increased antitumor TAMs in the TME. In addition, tumor antigen-specific CD8+ T cells were increased; consequently, tumor growth was significantly inhibited. Moreover, combination treatment with an anti-programmed cell death 1 (anti-PD-1) antibody and FF-10101 exhibited a far stronger antitumor effect than either treatment alone. In human cancer specimens, FF-10101 treatment reduced programmed cell death 1 ligand 1 (PD-L1) expression on TAMs, as observed in animal models. Thus, FF-10101 acts as an immunomodulatory agent that can reduce immunosuppressive TAMs and augment tumor antigen-specific T cell responses, thereby generating an immunostimulatory TME. We propose that FF-10101 is a potential candidate for successful combination cancer immunotherapy with immune checkpoint inhibitors, such as PD-1/PD-L1 blockade.

Integration of clinical outcomes and molecular features in extramedullary disease in multiple myeloma

Multiple myeloma (MM) remains incurable despite novel therapeutics. A major contributor to the development of relapsed/refractory and resistant MM is extraosseous extramedullary disease (EMD), whose molecular biology is still not fully understood. We analyzed 528 MM patients who presented to our institution between 2014 and 2021 and who had undergone molecular testing. We defined EMD as organ plasmacytoma distinct from bones and evaluated patients for the development of EMD with the goal of defining their molecular characteristics. Here, we show that RAS/BRAF mutations are likely essential for the development of EMD. Our results also indicate that the underlying reason for the negative outcomes in patients with poor prognostic factors such as duplication 1q and deletion 17p is largely due to the development of EMD. However, the presence of TP53 mutation remains a poor prognostic factor regardless of EMD development. Furthermore, mutation sites of TP53 were different between EMD versus non-EMD patients, with gain-of-function mutations enriched in patients with EMD. Our data highlights distinct molecular abnormalities in patients with EMD and provides potential mechanistic insights for novel therapeutic targets for the future.

Bubble Ticket Trip: Exploring the Mechanism of miRNA Sorting into Exosomes and Maintaining the Stability of Tumor Microenvironment

Exosomes are vesicles ranging from 30 to 100 nanometers in size that show great potential as carriers for therapeutic uses and drug delivery. Enriching a specific set of miRNAs in exosomes emphasizes the existence of particular sorting mechanisms that manage the targeted cargo packaging. The molecular mechanism for miRNA sorting has not been understood. It is crucial to understand the mechanism of exosome encapsulation to develop its therapeutic potential. In this review, we will explore the particular processes through which exosomes naturally encapsulate miRNA, as well as discuss the effect on tumors after encapsulation of miRNAs. We also summarize the effects of targeted drug delivery using genetic engineering and chemical methods to modify exosome-encapsulated miRNA. Finally, gaining insight into how exosome cargo is sorted could be applied in clinical settings for precise drug delivery and to hinder the progression of diseases.

Mutant p53-Mediated Tumor Secretome: Bridging Tumor Cells and Stromal Cells

The tumor secretome comprises the totality of protein factors secreted by various cell components within the tumor microenvironment, serving as the primary medium for signal transduction between tumor cells and between tumor cells and stromal cells. The deletion or mutation of the p53 gene leads to alterations in cellular secretion characteristics, contributing to the construction of the tumor microenvironment in a cell non-autonomous manner. This review discusses the critical roles of mutant p53 in regulating the tumor secretome to remodel the tumor microenvironment, drive tumor progression, and influence the plasticity of cancer-associated fibroblasts (CAFs) as well as the dynamics of tumor immunity by focusing on both secreted protein expression and secretion pathways. The aim is to provide new insights for targeted cancer therapies.

From regulation to deregulation of p53 in hematologic malignancies: implications for diagnosis, prognosis and therapy

The p53 protein, encoded by the TP53 gene, serves as a critical tumor suppressor, playing a vital role in maintaining genomic stability and regulating cellular responses to stress. Dysregulation of p53 is frequently observed in hematological malignancies, significantly impacting disease progression and patient outcomes. This review aims to examine the regulatory mechanisms of p53, the implications of TP53 mutations in various hematological cancers, and emerging therapeutic strategies targeting p53. We conducted a comprehensive literature review to synthesize recent findings related to p53's multifaceted role in hematologic cancers, focusing on its regulatory pathways and therapeutic potential. TP53 mutations in hematological malignancies often lead to treatment resistance and poor prognosis. Current therapeutic strategies, including p53 reactivation and gene therapy, show promise in improving treatment outcomes. Understanding the intricacies of p53 regulation and the consequences of its mutations is essential for developing effective diagnostic and therapeutic strategies in hematological malignancies, ultimately enhancing patient care and survival.

Hexokinase 2 senses fructose in tumor-associated macrophages to promote colorectal cancer growth

Fructose is associated with colorectal cancer tumorigenesis and metastasis through ketohexokinase-mediated metabolism in the colorectal epithelium, yet its role in the tumor immune microenvironment remains largely unknown. Here, we show that a modest amount of fructose, without affecting obesity and associated complications, promotes colorectal cancer tumorigenesis and growth by suppressing the polarization of M1-like macrophages. Fructose inhibits M1-like macrophage polarization independently of fructose-mediated metabolism. Instead, it serves as a signal molecule to promote the interaction between hexokinase 2 and inositol 1,4,5-trisphophate receptor type 3, the predominant Ca2+ channel on the endoplasmic reticulum. The interaction reduces Ca2+ levels in cytosol and mitochondria, thereby suppressing the activation of mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 1 (STAT1) as well as NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation. Consequently, this impedes M1-like macrophage polarization. Our study highlights the critical role of fructose as a signaling molecule that impairs the polarization of M1-like macrophages for tumor growth.

Characterization and analysis of extracellular vesicle-derived miRNAs from different adipose tissues in mice

Adipose tissue is traditionally classified into two main types based on their functions: brown adipose tissue (BAT) and white adipose tissue (WAT). Each type plays a distinct role in the body's energy metabolism. Additionally, a third type, beige adipose tissue, can develop within subcutaneous WAT (including inguinal WAT, iWAT) in response to specific stimuli and exhibits characteristics of both BAT and WAT. Extracellular vesicles (EVs) are crucial for intercellular communication, carrying a diverse array of biomolecules such as proteins, lipids, and nucleic acids. While the functional diversity and endocrine roles of adipose tissues are well-documented, a comparative analysis of the functions of EVs released by different adipose tissues from mice housed at room temperature has not been thoroughly explored. MicroRNAs (miRNAs), which are highly enriched in small extracellular vesicles (sEVs), offer a promising avenue for investigating the complex functions and unique roles of various adipose tissues. In this study, we isolated sEVs from different adipose tissues under basal conditions and performed a comprehensive analysis of their miRNA content. By comparing miRNA profiles across different adipose tissues, we aim to elucidate the potential roles of sEV-derived miRNAs in mediating intercellular communication and the distinct physiological functions of adipose tissues. Understanding the molecular features of miRNAs in adipose tissue EVs could reveal new aspects of adipose tissue biology and lay the groundwork for further research into their physiological significance.

Multiple roles of p53 in cancer development: Regulation of tumor microenvironment, m6A modification and diverse cell death mechanisms

BACKGROUND

The protein p53, encoded by the most frequently mutated gene TP53 in human cancers, has diverse functions in tumor suppression. As a best known transcription factor, p53 can regulate various fundamental cellular responses, ranging from the cell-cycle arrest, DNA repair, senescence to the programmed cell death (PCD), which includes autophagy, apoptosis, ferroptosis, cuproptosis, pyroptosis and disulfidoptosis. Accumulating evidence has indicated that the tumor microenvironment (TME), N6-methyladenosine (m6A) modification and diverse PCD are important for the progression, proliferation and metastases of cancers.

AIM OF REVIEW

This paper aims to systematically and comprehensively summarize the multiple roles of p53 in the development of cancers from the regulation of TME, m6A Modification and diverse PCD.

KEY SCIENTIFIC CONCEPTS OF REVIEW

TME, a crucial local homeostasis environment, influences every step of tumorigenesis and metastasis. m6A, the most prevalent and abundant endogenous modification in eukaryotic RNAs, plays an essential role in various biological processes, containing the progression of cancers. Additionally, PCD is an evolutionarily conserved mechanism of cell suicide and a common process in living organisms. Some forms of PCD contribute to the occurrence and development of cancer. However, the complex roles of p53 within the TME, m6A modification and diverse PCD mechanisms are still not completely understood. Presently, the function roles of p53 including the wild-type and mutant p53 in different context are summarized. Additionally, the interaction between the cancer immunity, cancer cell death and RNA m6A methylation and the p53 regulation during the development and progress of cancers were discussed. Moreover, the key molecular mechanisms by which p53 participates in the regulation of TME, m6A and diverse PCD are also explored. All the findings will facilitate the development of novel therapeutic approaches.

Extracellular vesicles in cancer: golden goose or Trojan horse

Intercellular communication can be mediated by direct cell-to-cell contact and indirect interactions through secretion of soluble chemokines, cytokines, and growth factors. Extracellular vesicles (EVs) have emerged as important mediators of cell-to-cell and cell-to-environment communications. EVs from tumor cells, immune cells, and stromal cells can remodel the tumor microenvironment and promote cancer cell survival, proliferation, metastasis, immune evasion, and therapeutic resistance. Most importantly, EVs as natural nanoparticles can be manipulated to serve as a potent delivery system for targeted cancer therapy. EVs can be engineered or modified to improve their ability to target tumors and deliver therapeutic substances, such as chemotherapeutic drugs, nucleic acids, and proteins, for the treatment of cancer. This review provides an overview of the biogenesis and recycling of EVs, discusses their roles in cancer development, and highlights their potential as a delivery system for targeted cancer therapy.

Unlocking the Secrets of Extracellular Vesicles: Orchestrating Tumor Microenvironment Dynamics in Metastasis, Drug Resistance, and Immune Evasion

Extracellular vehicles (EVs) are gaining increasing recognition as central contributors to the intricate landscape of the tumor microenvironment (TME). This manuscript provides an extensive examination of the multifaceted roles played by EVs in shaping the TME, with a particular emphasis on their involvement in metastasis, drug resistance, and immune evasion. Metastasis, the process by which cancer cells disseminate to distant sites, remains a formidable challenge in cancer management. EVs, encompassing exosomes and microvesicles, have emerged as critical participants in this cascade of events. They facilitate the epithelial-to-mesenchymal transition (EMT), foster pre-metastatic niche establishment, and enhance the invasive potential of cancer cells. This manuscript delves into the intricate molecular mechanisms underpinning these processes, underscoring the therapeutic potential of targeting EVs to impede metastasis. Drug resistance represents a persistent impediment to successful cancer treatment. EVs are instrumental in intrinsic and acquired drug resistance, acting as mediators of intercellular communication. They ferry molecules like miRNAs and proteins, which confer resistance to conventional chemotherapy and targeted therapies. This manuscript scrutinizes the diverse strategies employed by EVs in propagating drug resistance while also considering innovative approaches involving EV-based drug delivery systems to counteract this phenomenon. Immune evasion is a hallmark of cancer, and EVs are central in sculpting the immunosuppressive milieu of the TME. Tumor-derived EVs thwart immune responses through various mechanisms, including T cell dysfunction induction, the expansion of regulatory T cells (Tregs), and polarization of macrophages towards an immunosuppressive phenotype. In addition, the manuscript explores the diagnostic potential of EVs as biomarkers and their role as therapeutic agents in immune checkpoint blockade therapies. This manuscript provides a comprehensive overview of EV's pivotal role in mediating intricate interactions within the TME, ultimately influencing cancer progression and therapeutic outcomes. A profound understanding of EV-mediated processes in metastasis, drug resistance, and immune evasion opens up promising avenues for developing innovative therapeutic strategies and identifying valuable biomarkers in the ongoing battle against cancer.

Role of exosomal non‑coding RNAs in ovarian cancer (Review)

Ovarian cancer (OC) is a common gynecological disease with a high mortality rate worldwide due to its insidious nature and undetectability at an early stage. The standard treatment, combining platinum‑based chemotherapy with cytoreductive surgery, has suboptimal results. Therefore, early diagnosis of OC is crucial. All cell types secrete extracellular vesicles, particularly exosomes. Exosomes, which contain lipids, proteins, DNA and non‑coding RNAs (ncRNAs), are novel methods of intercellular communication that participate in tumor development and progression. ncRNAs are categorized by size into long ncRNAs (lncRNAs) and small ncRNAs (sncRNAs). sncRNAs further include transfer RNAs, small nucleolar RNAs, PIWI‑interacting RNAs and microRNAs (miRNAs). miRNAs inhibit protein translation and promote messenger RNA (mRNA) cleavage to suppress gene expression. By sponging downstream miRNAs, lncRNAs and circular RNAs can regulate target gene expression, thereby weakening the interactions between miRNAs and mRNAs. Exosomes and exosomal ncRNAs, commonly present in human biological fluids, are promising biomarkers for OC. The present article aimed to review the potential role of exosomal ncRNAs in the diagnosis and prognosis of OC by summarizing the characteristics, processes, roles and isolation methods of exosomes and exosomal ncRNAs.

TP53 Mutation-Mediated Immune Evasion in Cancer: Mechanisms and Therapeutic Implications

Mutation in p53 is the most frequent event in cancer development and a leading cause of cancer therapy resistance due to evasion of the apoptosis cascade. Beyond chemotherapies and radiation therapies, growing evidence indicates that p53-mutant tumors are resistant to a broad range of immune-based therapies, such as immune checkpoint inhibitors, chimeric antigen receptor (CAR) T, and hematopoietic stem cell transplantation (HSCT). This highlights the role of p53 mutations in driving immune evasion of tumor cells. In this review, we first summarize recent studies revealing mechanisms by which p53-mutant tumors evade immune surveillance from T cells, natural killer (NK) cells, and macrophages. We then review how these mutant tumor cells reshape the tumor microenvironment (TME), modulating bystander cells such as macrophages, neutrophils, and regulatory T (Treg) cells to foster immunosuppression. Additionally, we review clinical observations indicative of immune evasion associated with p53 loss or mutations. Finally, we discuss therapeutic strategies to enhance immune response in p53 wild-type (WT) or mutant tumors.

CircPRRC2C Promotes the Oncogenic Phenotypes of Laryngeal Squamous Cell Carcinoma Cells via MiR-136-5p/HOXD11 Axis

The involvement of circular RNAs (circRNAs) in laryngeal squamous cell carcinoma (LSCC) carcinogenesis has gradually been proposed. Herein, we aimed to explore the function and mechanism of circPRRC2C in LSCC. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were used for detecting the content of genes and proteins. In vitro experiments were conducted using 5-ethynyl-2'-deoxyuridine, colony formation, flow cytometry, and transwell assays. The binding between miR-136-5p and circPRRC2C or Homeobox D11 (HOXD11) was confirmed by using the dual-luciferase reporter assay. The murine xenograft model was established for in vivo analysis. The commercial kit was used for exosome separation. CircPRRC2C is a stable circRNA, and was highly expressed in LSCC tissues and cell lines. Functionally, circPRRC2C deficiency impaired LSCC cell proliferation, migration and invasion but induced cell apoptosis in vitro and impeded tumor growth in vivo, however, circPRRC2C overexpression showed the exact opposite effects. Mechanistically, circPRRC2C directly targeted miR-136-5p, which showed inhibitory effects on the growth and mobility of LSCC cells. Meanwhile, miR-136-5p directly targeted HOXD11, and circPRRC2C/miR-136-5p/HOXD11 formed a feedback loop in LSCC cells. Further rescue assays exhibited that circPRRC2C exerted its effects by miR-136-5p/HOXD11 axis. In addition, circPRRC2C was stably packaged into exosomes and showed potential diagnostic value for LSCC. CircPRRC2C acted as an oncogene to promote LSCC cell oncogenic phenotypes via miR-136-5p/HOXD11 axis, besides, circPRRC2C was stably packaged into exosomes, indicating the potential application of circPRRC2C-targeting agents in the treatment in LSCC.

Dynamic immunoediting by macrophages in homologous recombination deficiency-stratified pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, notably resistant to existing therapies. Current research indicates that PDAC patients deficient in homologous recombination (HR) benefit from platinum-based treatments and poly-ADP-ribose polymerase inhibitors (PARPi). However, the effectiveness of PARPi in HR-deficient (HRD) PDAC is suboptimal, and significant challenges remain in fully understanding the distinct characteristics and implications of HRD-associated PDAC. We analyzed 16 PDAC patient-derived tissues, categorized by their homologous recombination deficiency (HRD) scores, and performed high-plex immunofluorescence analysis to define 20 cell phenotypes, thereby generating an in-situ PDAC tumor-immune landscape. Spatial phenotypic-transcriptomic profiling guided by regions-of-interest (ROIs) identified a crucial regulatory mechanism through localized tumor-adjacent macrophages, potentially in an HRD-dependent manner. Cellular neighborhood (CN) analysis further demonstrated the existence of macrophage-associated high-ordered cellular functional units in spatial contexts. Using our multi-omics spatial profiling strategy, we uncovered a dynamic macrophage-mediated regulatory axis linking HRD status with SIGLEC10 and CD52. These findings demonstrate the potential of targeting CD52 in combination with PARPi as a therapeutic intervention for PDAC.

Roles of M1 Macrophages and Their Extracellular Vesicles in Cancer Therapy

Tumor-associated macrophages (TAMs) are inflammatory cells that are important components of the tumor microenvironment. TAMs are functionally heterogeneous and divided into two main subpopulations with distinct and opposite functions: M1 and M2 macrophages. The secretory function of TAMs is essential for combating infections, regulating immune responses, and promoting tissue repair. Extracellular vesicles (EVs) are nanovesicles that are secreted by cells. They play a crucial role in mediating intercellular information transfer between cells. EVs can be secreted by almost all types of cells, and they contain proteins, microRNAs, mRNAs, and even long non-coding RNAs (lncRNAs) that have been retained from the parental cell through the process of biogenesis. EVs can influence the function and behavior of target cells by delivering their contents, thus reflecting, to some extent, the characteristics of their parental cells. Here, we provide an overview of the role of M1 macrophages and their EVs in cancer therapy by exploring the impact of M1 macrophage-derived EVs (M1-EVs) on tumors by transferring small microRNAs. Additionally, we discuss the potential of M1-EVs as drug carriers and the possibility of reprogramming M2 macrophages into M1 macrophages for disease treatment. We propose that M1-EVs play a crucial role in cancer therapy by transferring microRNAs and loading them with drugs. Reprogramming M2 macrophages into M1 macrophages holds great promise in the treatment of cancers.

Master regulator: p53's pivotal role in steering NK-cell tumor patrol

The p53 protein, encoded by TP53, is a tumor suppressor that plays a critical role in regulating apoptosis, cell cycle regulation, and angiogenesis in tumor cells via controlling various downstream signals. Natural killer (NK) cell-mediated immune surveillance is a vital self-defense mechanism against cancer and other diseases, with NK cell activity regulated by various mechanisms. Among these, p53 plays a significant role in immune regulation by maintaining the homeostasis and functionality of NK cells. It enhances the transcriptional activity of NK cell-activating ligands and downregulates inhibitory ligands to boost NK cell activation and tumor-killing efficacy. Additionally, p53 influences NK cell cytotoxicity by promoting apoptosis, autophagy, and ferroptosis in different tumor cells. p53 is involved in the regulation of NK cell activity and effector functions through multiple pathways. p53 also plays a pivotal role in the tumor microenvironment (TME), regulating the activity of NK cells. NK cells are critical components of the TME and are capable of directly killing tumor cells. And p53 mutates in numerous cancers, with the most common alteration being a missense mutation. These mutations are commonly associated with poor survival rates in patients with cancer. This review details p53's role in NK cell tumor immunosurveillance, summarizing how p53 enhances NK cell recognition and tumor destruction. We also explore the potential applications of p53 in tumor immunotherapy, discussing strategies for modulating p53 to enhance NK cell function and improve the efficacy of tumor immunotherapy, along with the associated challenges. Understanding the interaction between p53 and NK cells within the TME is crucial for advancing NK cell-based immunotherapy and developing p53-related novel therapeutics.

Exercise-downregulated CD300E acted as a negative prognostic implication and tumor-promoted role in pan-cancer

BACKGROUND

Breast cancer ranks as one of the most prevalent malignancies among women globally, with increasing incidence rates. Physical activity, particularly exercise, has emerged as a potentially significant modifier of cancer prognosis, influencing tumor biology and patient outcomes.

METHODS

Using a murine breast cancer model, we established a control and an exercise group, where the latter was subjected to 21 days of voluntary running. RNA Sequencing, bioinformatics analysis, pan-cancer analysis, and cell experiments were performed to validate the underlying mechanisms.

RESULTS

We observed that exercise significantly reduced tumor size and weight, without notable changes in body weight, suggesting that physical activity can modulate tumor dynamics. mRNA sequencing post-exercise revealed substantial downregulation of CD300E in the exercise group, accompanied by alterations in critical pathways such as MicroRNAs in cancers and the Calcium signaling pathway. Expanding our analysis to a broader cancer spectrum, CD300E demonstrated significant expression variability across multiple cancer types, with pronounced upregulation in myeloma, ovarian, lung, and colorectal cancers. This upregulation was correlated with poorer prognostic outcomes, emphasizing CD300E's potential role as a prognostic marker and therapeutic target. Moreover, CD300E expression was associated with cancer cell proliferation and apoptosis.

CONCLUSION

The study highlights the dual role of exercise in modulating gene expression relevant to tumor growth and the potential of CD300E as a target in cancer therapeutics. Further research is encouraged to explore the mechanisms by which exercise and CD300E influence cancer progression and to develop targeted strategies that could enhance patient outcomes in clinical settings.

p53 at the crossroads of tumor immunity

The p53 tumor suppressor protein has a plethora of cell-intrinsic functions and consequences that impact diverse cell types and tissues. Recent studies are beginning to unravel how wild-type and mutant p53 work in distinct ways to modulate tumor immunity. This sets up a disequilibrium between tumor immunosurveillance and escape therefrom. The ability to exploit this emerging knowledge for translational approaches may shape immunotherapy and targeted therapeutics in the future, especially in combinatorial settings.

p53 Genetics and Biology in Lung Carcinomas: Insights, Implications and Clinical Applications

The TP53 gene is renowned as a tumor suppressor, playing a pivotal role in overseeing the cell cycle, apoptosis, and maintaining genomic stability. Dysregulation of p53 often contributes to the initiation and progression of various cancers, including lung cancer (LC) subtypes. The review explores the intricate relationship between p53 and its role in the development and progression of LC. p53, a crucial tumor suppressor protein, exists in various isoforms, and understanding their distinct functions in LC is essential for advancing our knowledge of this deadly disease. This review aims to provide a comprehensive literature overview of p53, its relevance to LC, and potential clinical applications.

Extracellular vesicles as modulators of monocyte and macrophage function in tumors

The tumor microenvironment (TME) harbors several cell types, such as tumor cells, immune cells, and non-immune cells. These cells communicate through several mechanisms, such as cell-cell contact, cytokines, chemokines, and extracellular vesicles (EVs). Tumor-derived vesicles are known to have the ability to modulate the immune response. Monocytes are a subset of circulating innate immune cells and play a crucial role in immune surveillance, being recruited to tissues where they differentiate into macrophages. In the context of tumors, it has been observed that tumor cells can attract monocytes to the TME and induce their differentiation into tumor-associated macrophages with a pro-tumor phenotype. Tumor-derived EVs have emerged as essential structures mediating this process. Through the transfer of specific molecules and signaling factors, tumor-derived EVs can shape the phenotype and function of monocytes, inducing the expression of cytokines and molecules by these cells, thus modulating the TME towards an immunosuppressive environment.

A study of microRNAs as new prognostic biomarkers in anal cancer patients

BACKGROUND

MicroRNA (MiR) influences the growth of cancer by regulation of mRNA for 50-60% of all genes. We present as per our knowledge the first global analysis of microRNA expression in anal cancer patients and their prognostic impact.

METHODS

Twenty-nine patients with T1-4 N0-3 M0 anal cancer treated with curative intent from September 2003 to April 2011 were included in the study. RNA was extracted from fresh frozen tissue and sequenced using NGS. Differentially expressed microRNAs were identified using the R-package DEseq2 and the endpoints were time to progression (TTP) and cancer specific survival (CSS).

RESULTS

Five microRNAs were significantly associated with 5-year progression free survival (PFS): Low expression of two microRNAs was associated with higher PFS, miR-1246 (100% vs. 55.6%, p = 0.008), and miR-135b-5p (92.9% vs. 59.3%, p = 0.041). On the other hand, high expressions of three microRNAs were associated with higher PFS, miR-148a-3p (93.3% vs. 53.6%, p = 0.025), miR-99a-5p (92.9% vs. 57.1%, p = 0.016), and let-7c-3p (92.9% vs. 57.1%, p = 0.016). Corresponding findings were documented for CSS.

INTERPRETATION

Our study identified five microRNAs as prognostic markers in anal cancer. MiR-1246 and microRNA-135b-5p were oncoMiRs (miRs with oncogene effects), while miR-148a-3p, miR- 99a-5p, and let-7c-3p acted as tumour suppressors in anal cancer patients.

APR-246 as a radiosensitization strategy for mutant p53 cancers treated with alpha-particles-based radiotherapy

Radiation therapy (RT) remains a common treatment for cancer patients worldwide, despite the development of targeted biological compounds and immunotherapeutic drugs. The challenge in RT lies in delivering a lethal dose to the cancerous site while sparing the surrounding healthy tissues. Low linear energy transfer (low-LET) and high linear energy transfer (high-LET) radiations have distinct effects on cells. High-LET radiation, such as alpha particles, induces clustered DNA double-strand breaks (DSBs), potentially inducing cell death more effectively. However, due to limited range, alpha-particle therapies have been restricted. In human cancer, mutations in TP53 (encoding for the p53 tumor suppressor) are the most common genetic alteration. It was previously reported that cells carrying wild-type (WT) p53 exhibit accelerated senescence and significant rates of apoptosis in response to RT, whereas cells harboring mutant p53 (mutp53) do not. This study investigated the combination of the alpha-emitting atoms RT based on internal Radium-224 (224Ra) sources and systemic APR-246 (a p53 reactivating compound) to treat tumors with mutant p53. Cellular models of colorectal cancer (CRC) or pancreatic ductal adenocarcinoma (PDAC) harboring mutant p53, were exposed to alpha particles, and tumor xenografts with mutant p53 were treated using 224Ra source and APR-246. Effects on cell survival and tumor growth, were assessed. The spread of alpha emitters in tumors was also evaluated as well as the spatial distribution of apoptosis within the treated tumors. We show that mutant p53 cancer cells exhibit radio-sensitivity to alpha particles in vitro and to alpha-particles-based RT in vivo. APR-246 treatment enhanced sensitivity to alpha radiation, leading to reduced tumor growth and increased rates of tumor eradication. Combining alpha-particles-based RT with p53 restoration via APR-246 triggered cell death, resulting in improved therapeutic outcomes. Further preclinical and clinical studies are needed to provide a promising approach for improving treatment outcomes in patients with mutant p53 tumors.

Genomic profiling informs therapies and prognosis for patients with hepatocellular carcinoma in clinical practice

Hepatocellular carcinoma (HCC) genomic research has discovered actionable genetic changes that might guide treatment decisions and clinical trials. Nonetheless, due to a lack of large-scale multicenter clinical validation, these putative targets have not been converted into patient survival advantages. So, it's crucial to ascertain whether genetic analysis is clinically feasible, useful, and whether it can be advantageous for patients. We sequenced tumour tissue and blood samples (as normal controls) from 111 Chinese HCC patients at Qingdao University Hospital using the 508-gene panel and the 688-gene panel, respectively. Approximately 95% of patients had gene variations related to targeted treatment, with 50% having clinically actionable mutations that offered significant information for targeted therapy. Immune cell infiltration was enhanced in individuals with TP53 mutations but decreased in patients with CTNNB1 and KMT2D mutations. More notably, we discovered that SPEN, EPPK1, and BRCA2 mutations were related to decreased median overall survival, although MUC16 mutations were not. Furthermore, we found mutant MUC16 as an independent protective factor for the prognosis of HCC patients after curative hepatectomy. In conclusion, this study connects genetic abnormalities to clinical practice and potentially identifies individuals with poor prognoses who may benefit from targeted treatment or immunotherapy.

Small extracellular vesicles: Multi-functional aspects in non-small cell lung carcinoma

Extracellular vesicles (EVs) impact normal and pathological cellular signaling through bidirectional trafficking. Exosomes, a subset of EVs possess biomolecules including proteins, lipids, DNA fragments and various RNA species reflecting a speculum of their parent cells. The involvement of exosomes in bidirectional communication and their biological constituents substantiate its role in regulating both physiology and pathology, including multiple cancers. Non-small cell lung cancer (NSCLC) is the most common lung cancers (85%) with high incidence, mortality and reduced overall survival. Lack of efficient early diagnostic and therapeutic tools hurdles the management of NSCLC. Interestingly, the exosomes from body fluids similarity with parent cells or tissue offers a potential future multicomponent tool for the early diagnosis of NSCLC. The structural twinning of exosomes with a cell/tissue and the competitive tumor derived exosomes in tumor microenvironment (TME) promotes the unpinning horizons of exosomes as a drug delivery, vaccine, and therapeutic agent. Exosomes in clinical point of view assist to trace: acquired resistance caused by various therapeutic agents, early diagnosis, progression, and surveillance. In an integrated approach, EV biomarkers offer potential cutting-edge techniques for the detection and diagnosis of cancer, though the purification, characterization, and biomarker identification processes for the translational research regarding EVs need further optimization.

Recent Advances on Mutant p53: Unveiling Novel Oncogenic Roles, Degradation Pathways, and Therapeutic Interventions

The p53 protein is the master regulator of cellular integrity, primarily due to its tumor-suppressing functions. Approximately half of all human cancers carry mutations in the TP53 gene, which not only abrogate the tumor-suppressive functions but also confer p53 mutant proteins with oncogenic potential. The latter is achieved through so-called gain-of-function (GOF) mutations that promote cancer progression, metastasis, and therapy resistance by deregulating transcriptional networks, signaling pathways, metabolism, immune surveillance, and cellular compositions of the microenvironment. Despite recent progress in understanding the complexity of mutp53 in neoplastic development, the exact mechanisms of how mutp53 contributes to cancer development and how they escape proteasomal and lysosomal degradation remain only partially understood. In this review, we address recent findings in the field of oncogenic functions of mutp53 specifically regarding, but not limited to, its implications in metabolic pathways, the secretome of cancer cells, the cancer microenvironment, and the regulating scenarios of the aberrant proteasomal degradation. By analyzing proteasomal and lysosomal protein degradation, as well as its connection with autophagy, we propose new therapeutical approaches that aim to destabilize mutp53 proteins and deactivate its oncogenic functions, thereby providing a fundamental basis for further investigation and rational treatment approaches for TP53-mutated cancers.

Harnessing exosomes in theranostic applications: advancements and insights in gastrointestinal cancer research

Exosomes are small extracellular vesicles (30-150 nm) that are formed by endocytosis containing complex RNA as well as protein structures and are vital in intercellular communication and can be used in gene therapy and drug delivery. According to the cell sources of origin and the environmental conditions they are exposed to, these nanovesicles are very heterogeneous and dynamic in terms of content (cargo), size and membrane composition. Exosomes are released under physiological and pathological conditions and influence the pathogenesis of cancers through various mechanisms, including angiogenesis, metastasis, immune dysregulation, drug resistance, and tumor growth/development. Gastrointestinal cancer is one of the deadliest types of cancer in humans and can involve organs e.g., the esophagus and stomach, or others such as the liver, pancreas, small intestine, and colon. Early diagnosis is very important in this field because the overall survival of patients is low due to diagnosis in late stages and recurrence. Also, various therapeutic strategies have failed and there is an unmet need for the new therapeutic agents. Exosomes can become promising candidates in gastrointestinal cancers as biomarkers and therapeutic agents due to their lower immunity and passing the main physiological barriers. In this work, we provide a general overview of exosomes, their biogenesis and biological functions. In addition, we discuss the potential of exosomes to serve as biomarkers, agents in cancer treatment, drug delivery systems, and effective vaccines in immunotherapy, with an emphasis on gastrointestinal cancers.

The multifaceted role of extracellular vesicles (EVs) in colorectal cancer: metastasis, immune suppression, therapy resistance, and autophagy crosstalk

Extracellular vesicles (EVs) are lipid bilayer structures released by all cells and widely distributed in all biological fluids. EVs are implicated in diverse physiopathological processes by orchestrating cell-cell communication. Colorectal cancer (CRC) is one of the most common cancers worldwide, with metastasis being the leading cause of mortality in CRC patients. EVs contribute significantly to the advancement and spread of CRC by transferring their cargo, which includes lipids, proteins, RNAs, and DNAs, to neighboring or distant cells. Besides, they can serve as non-invasive diagnostic and prognostic biomarkers for early detection of CRC or be harnessed as effective carriers for delivering therapeutic agents. Autophagy is an essential cellular process that serves to remove damaged proteins and organelles by lysosomal degradation to maintain cellular homeostasis. Autophagy and EV release are coordinately activated in tumor cells and share common factors and regulatory mechanisms. Although the significance of autophagy and EVs in cancer is well established, the exact mechanism of their interplay in tumor development is obscure. This review focuses on examining the specific functions of EVs in various aspects of CRC, including progression, metastasis, immune regulation, and therapy resistance. Further, we overview emerging discoveries relevant to autophagy and EVs crosstalk in CRC.

Driver Mutations in Pancreatic Cancer and Opportunities for Targeted Therapy

Pancreatic cancer is the sixth leading cause of cancer-related mortality globally. As the most common form of pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC) represents up to 95% of all pancreatic cancer cases, accounting for more than 300,000 deaths annually. Due to the lack of early diagnoses and the high refractory response to the currently available treatments, PDAC has a very poor prognosis, with a 5-year overall survival rate of less than 10%. Targeted therapy and immunotherapy are highly effective and have been used for the treatment of many types of cancer; however, they offer limited benefits in pancreatic cancer patients due to tumor-intrinsic and extrinsic factors that culminate in drug resistance. The identification of key factors responsible for PDAC growth and resistance to different treatments is highly valuable in developing new effective therapeutic strategies. In this review, we discuss some molecules which promote PDAC initiation and progression, and their potential as targets for PDAC treatment. We also evaluate the challenges associated with patient outcomes in clinical trials and implications for future research.

Molecular mechanism of radiation tolerance in lung adenocarcinoma cells using single-cell RNA sequencing

The efficacy of radiotherapy, a cornerstone in the treatment of lung adenocarcinoma (LUAD), is profoundly undermined by radiotolerance. This resistance not only poses a significant clinical challenge but also compromises patient survival rates. Therefore, it is important to explore this mechanism for the treatment of LUAD. Multiple public databases were used for single-cell RNA sequencing (scRNA-seq) data. We filtered, normalized and downscaled scRNA-seq data based on the Seurat package to obtain different cell subpopulations. Subsequently, the ssGSEA algorithm was used to assess the enrichment scores of the different cell subpopulations, and thus screen the cell subpopulations that are most relevant to radiotherapy tolerance based on the Pearson method. Finally, pseudotime analysis was performed, and a preliminary exploration of gene mutations in different cell subpopulations was performed. We identified HIST1H1D+ A549 and PIF1+ A549 as the cell subpopulations related to radiotolerance. The expression levels of cell cycle-related genes and pathway enrichment scores of these two cell subpopulations increased gradually with the extension of radiation treatment time. Finally, we found that the proportion of TP53 mutations in patients who had received radiotherapy was significantly higher than that in patients who had not received radiotherapy. We identified two cellular subpopulations associated with radiotherapy tolerance, which may shed light on the molecular mechanisms of radiotherapy tolerance in LUAD and provide new clinical perspectives.

Exosome-Mediated Paracrine Signaling Unveils miR-1246 as a Driver of Aggressiveness in Fusion-Negative Rhabdomyosarcoma

Rhabdomyosarcoma is a pediatric cancer associated with aggressiveness and a tendency to develop metastases. Fusion-negative rhabdomyosarcoma (FN-RMS) is the most commonly occurring subtype of RMS, where metastatic disease can hinder treatment success and decrease survival rates. RMS-derived exosomes were previously demonstrated to be enriched with miRNAs, including miR-1246, possibly contributing to disease aggressiveness. We aimed to decipher the functional impact of exosomal miR-1246 on recipient cells and its role in promoting aggressiveness. Treatment of normal fibroblasts with FN-RMS-derived exosomes resulted in a significant uptake of miR-1246 paired with an increase in cell proliferation, migration, and invasion. In turn, delivery of miR-1246-mimic lipoplexes promoted fibroblast proliferation, migration, and invasion in a similar manner. Conversely, when silencing miR-1246 in FN-RMS cells, the resulting derived exosomes demonstrated reversed effects on recipient cells' phenotype. Delivery of exosomal miR-1246 targets GSK3β and promotes β-catenin nuclear accumulation, suggesting a deregulation of the Wnt pathway, known to be important in tumor progression. Finally, a pilot clinical study highlighted, for the first time, the presence of high exosomal miR-1246 levels in RMS patients' sera. Altogether, our results demonstrate that exosomal miR-1246 has the potential to alter the tumor microenvironment of FN-RMS cells, suggesting its potential role in promoting oncogenesis.

Function and mechanism of exosomes derived from different cells as communication mediators in colorectal cancer metastasis

Colorectal cancer (CRC) ranks as the second leading cause of cancer-related mortality, with metastasis being the primary determinant of poor prognosis in patients. Investigating the molecular mechanisms underlying CRC metastasis is currently a prominent and challenging area of research. Exosomes, as crucial intercellular communication mediators, facilitate the transfer of metabolic and genetic information from cells of origin to recipient cells. Their roles in mediating information exchange between CRC cells and immune cells, fibroblasts, and other cell types are pivotal in reshaping the tumor microenvironment, regulating key biological processes such as invasion, migration, and formation of pre-metastatic niche. This article comprehensively examines the communication function and mechanism of exosomes derived from different cells in cancer metastasis, while also presenting an outlook on current research advancements and future application prospects. The aim is to offer a distinctive perspective that contributes to accurate diagnosis and rational treatment strategies for CRC.

The Uridylyl Transferase TUT7-Mediated Accumulation of Exosomal miR-1246 Reprograms TAMs to Support CRC Progression

Tumor-associated macrophages (TAMs) play a crucial role in promoting tumor growth and dissemination, motivating a search for key targets to interfere with the activation of TAMs or reprogram TAMs into the tumor-suppressive type. To gain insight into the mechanisms of macrophage polarization, a designed co-culture system is established, allowing for the education of macrophages in a manner that closely mimics the intricacies of TAMs in the tumor immune microenvironment (TIME). Through database mining, exosomal miR-1246 is identified and is then validated. Exosomal miR-1246-driven polarization of TAMs disrupts the infiltration and function of CD8+ T cells. Mechanically, the amassment of exosomal miR-1246 stems from TUT7-mediated degradation of small noncoding RNA, a process stabilized by SNRPB, but not the precursor of miR-1246. Moreover, an Exo-motif is present in the exosomal miR-1246 sequence, enabling it to bind with the exosomal sorting protein hnRNPA2B1. RNA-seq analysis reveals that exogenous miR-1246 modulates the polarization of TAMs at a post-transcriptional level, emphasizing the pivotal role of the NLRP3 in macrophage polarization. In conclusion, the findings underscore the importance of exosomal miR-1246 as a trigger of macrophage reprogramming and uncover a novel mechanism for its enhanced presence in the TIME.

Exosomes promote pre-metastatic niche formation in colorectal cancer

It is well known that colorectal cancer (CRC) has a high morbidity rate, a poor prognosis when metastasized, and a greatly shortened 5-year survival rate. Therefore, understanding the mechanism of tumor metastasis is still important. Based on the "seed and soil" theory, the concept of " premetastatic niche (PMN)" was introduced by Kaplan et al. The complex interaction between primary tumors and the metastatic organ provides a beneficial microenvironment for tumor cells to colonize at a distance. With further exploration of the PMN, exosomes have gradually attracted interest from researchers. Exosomes are extracellular vesicles secreted from cells that include various biological information and are involved in communication between cells. As a key molecule in the PMN, exosomes are closely related to tumor metastasis. In this article, we obtained information by conducting a comprehensive search across academic databases including PubMed and Web of Science using relevant keywords. Only recent, peer-reviewed articles published in the English language were considered for inclusion. This study aims to explore in depth how exosomes promote the formation of pre-metastatic microenvironment (PMN) in colorectal cancer and its related mechanisms.

Dissemination of the Flavivirus Subgenomic Replicon Genome and Viral Proteins by Extracellular Vesicles

Extracellular vesicles (EVs) such as exosomes have been shown to play physiological roles in cell-to-cell communication by delivering various proteins and nucleic acids. In addition, several studies revealed that the EVs derived from the cells that are infected with certain viruses could transfer the full-length viral genomes, resulting in EVs-mediated virus propagation. However, the possibility cannot be excluded that the prepared EVs were contaminated with infectious viral particles. In this study, the cells that harbor subgenomic replicon derived from the Japanese encephalitis virus and dengue virus without producing any replication-competent viruses were employed as the EV donor. It was demonstrated that the EVs in the culture supernatants of those cells were able to transfer the replicon genome to other cells of various types. It was also shown that the EVs were incorporated by the recipient cells primarily through macropinocytosis after interaction with CD33 and Tim-1/Tim-4 on HeLa and K562 cells, respectively. Since the methods used in this study are free from contamination with infectious viral particles, it is unequivocally indicated that the flavivirus genome can be transferred by EVs from cell to cell, suggesting that this pathway, in addition to the classical receptor-mediated infection, may play some roles in the viral propagation and pathogenesis.

Urocortin-1 promotes colorectal cancer cell migration and proliferation and inhibits apoptosis via inhibition of the p53 signaling pathway

PURPOSE

To investigate the effect of urocortin-1 (UCN-1) on growth, migration, and apoptosis in colorectal cancer (CRC) in vivo and vitro and the mechanism by which UCN-1 modulates CRC cells in vitro.

METHODS

The correlation between UCN-1 and CRC was evaluated using The Cancer Genome Atlas (TCGA) database and a tissue microarray. The expression of UCN-1 in CRC cells was assessed using quantitative real-time polymerase chain reaction (RT-qPCR) and western blotting. In vitro, the influence of UCN-1 on the proliferation, apoptosis, and migration of HT-29, HCT-116, and RKO cells was explored using the celigo cell counting assay or cell counting kit-8 (CCK8), flow cytometry, and wound healing or Transwell assays, respectively. In vivo, the effect of UCN-1 on CRC growth and progression was evaluated in nude mice. The downstream pathway underlying UCN-1-mediated regulation of CRC was determined using the phospho-kinase profiler array in RKO cells. Lentiviruses were used to knockdown or upregulate UCN-1 expression in cells.

RESULTS

Both the TCGA and tissue microarray results showed that UCN-1 was strongly expressed in the tissues of patients with CRC. Furthermore, the tissue microarray results showed that the expression of UCN-1 was higher in male than in female patients, and high expression of UCN-1 was associated with higher risk of lymphatic metastasis and later pathological stage. UCN-1 knockdown caused a reduction in CRC cell proliferation, migration, and colony formation, as well as an increase in apoptosis. In xenograft experiments, tumors generated from RKO cells with UCN-1 knockdown exhibited reduced volumes and weights. A reduction in the expression of Ki-67 in xenograft tumors indicated that UCN-1 knockdown curbed tumor growth. The human phospho-kinase array showed that the p53 signaling pathway participated in UCN-1-mediated CRC development. The suppression in migration and proliferation caused by UCN-1 knockdown was reversed by inhibitors of p53 signal pathway, while the increase in cell apoptosis was suppressed. On the other hand, overexpression of UCN-1 promoted proliferation and migration and inhibited apoptosis in CRC cells. Overexpression of p53 reversed the effect of UCN-1 overexpression on CRC development.

CONCLUSION

UCN-1 promotes migration and proliferation and inhibits apoptosis via inhibition of the p53 signaling pathway.

Decoding the secrets of longevity: unraveling nutraceutical and miRNA-Mediated aging pathways and therapeutic strategies

MicroRNAs (miRNAs) are short RNA molecules that are not involved in coding for proteins. They have a significant function in regulating gene expression after the process of transcription. Their participation in several biological processes has rendered them appealing subjects for investigating age-related disorders. Increasing data indicates that miRNAs can be influenced by dietary variables, such as macronutrients, micronutrients, trace minerals, and nutraceuticals. This review examines the influence of dietary factors and nutraceuticals on the regulation of miRNA in relation to the process of aging. We examine the present comprehension of miRNA disruption in age-related illnesses and emphasize the possibility of dietary manipulation as a means of prevention or treatment. Consolidating animal and human research is essential to validate the significance of dietary miRNA control in living organisms, despite the abundance of information already provided by several studies. This review elucidates the complex interaction among miRNAs, nutrition, and aging, offering valuable insights into promising areas for further research and potential therapies for age-related disorders.

Investigation of cellular communication and signaling pathways in tumor microenvironment for high TP53-expressing osteosarcoma cells through single-cell RNA sequencing

Osteosarcoma (OS) stands as the most prevalent primary bone cancer in children and adolescents, and its limited treatment options often result in unsatisfactory outcomes, particularly for metastatic cases. The tumor microenvironment (TME) has been recognized as a crucial determinant in OS progression. However, the intercellular dynamics between high TP53-expressing OS cells and neighboring cell types within the TME are yet to be thoroughly understood. In our study, we harnessed the single-cell RNA sequencing (scRNA-seq) technology in combination with the computational tool-Cellchat, aiming to elucidate the intercellular communication networks present within OS. Through meticulous quantitative inference and subsequent analysis of these networks, we succeeded in identifying significant signaling pathways connecting high TP53-expressing OS cells with proximate cell types, namely Macrophages, Monocytes, Endothelial Cells, and PVLs. This research brings forth a nuanced understanding of the intricate patterns and coordination involved in the TME's intercellular communication signals. These findings not only provide profound insights into the molecular mechanisms underpinning OS but also indicate potential therapeutic targets that could revolutionize treatment strategies.