CircITGB6 promotes ovarian cancer cisplatin resistance by resetting tumor-associated macrophage polarization toward the M2 phenotype

Tetrahydrocurcumin alleviates colorectal tumorigenesis by modulating the SPP1/CD44 axis and preventing M2 tumor-associated macrophage polarization

BACKGROUND

Recent studies show that secreted phosphoprotein 1 (SPP1) is linked to the progression of various cancers, including colorectal cancer (CRC). SPP1 also promotes M2 macrophage polarization, contributing to immune evasion in the tumor microenvironment. Tetrahydrocurcumin (THC) has been reported to alleviate CRC, but the mechanism remains unclear.

PURPOSE

The study aimed to explore how THC modulated the SPP1/CD44 axis to inhibit M2 polarization and suppress CRC development.

METHODS

Azoxymethane/dextran sulfate sodium (AOM/DSS)-induced mouse model was used to assess the anti-CRC effects of THC. Transcriptome sequencing was conducted to identify the key targets of THC in CRC. The effects of THC on CRC cells were evaluated by CCK-8, colony formation, migration assays, immunofluorescence staining and flow cytometry. Human monocytic cells, THP-1, and colon cancer cell line, HCT116, were co-cultured, both directly or indirectly, to mimic the tumor-macrophage interactions, and investigate the role of SPP1/CD44 axis and the intervention effect of THC.

RESULTS

THC significantly inhibited CRC carcinogenesis in mice and improved pathologic symptoms, serum inflammatory markers, and intestinal barrier integrity. THC inhibited CRC cell proliferation, migration and colony formation, while promoting apoptosis. Transcriptome analysis identified SPP1 as a key target of THC against CRC. SPP1 facilitated CRC progression by activating the ERK signaling pathway and maintaining the M2-like phenotype of macrophage, which further exacerbated this response. THC inhibited CRC development by targeting the SPP1/CD44 axis, rather than the integrin pathway.

CONCLUSIONS

SPP1 played a crucial role in maintaining the M2 phenotype of macrophage and promoting CRC cells proliferation. THC inhibited the activation of ERK signals in CRC cells and phenotypic transformation of M2-like macrophages through the SPP1/CD44 axis, thereby regulating the tumor immune microenvironment to exert anti-CRC effect.

Circ_0044362 Facilitates the Progression of Epithelial Ovarian Cancer via Enhancing HOXB4 Transcription to Activate the RUNX1/IGFBP3 Axis

Increasing numbers of studies have elucidated the emerging roles of circular RNA (circRNA) in cancer progression. However, the function of circRNAs in modulating their parental genes in ovarian cancer remains poorly understood. In this study, we identified that circ_0044362, a circRNA derived from homeobox B4 (HOXB4), significantly promotes the expression of its parental gene HOXB4 in ovarian cancer. Functionally, circ_0044362 promotes the malignant phenotypes of ovarian cancer cells. Further analysis revealed that circ_0044362 facilitates the transcriptional activation of its parental gene HOXB4 by directly guiding U1 small nuclear ribonucleoprotein (snRNP) to its promoter region, thereby enhancing the oncogenic behaviors of ovarian cancer cells. Furthermore, HOXB4 positively regulates runt-related transcription factor 1 (RUNX1) expression, with RUNX1 serving as a transcription factor to promote the transcription of insulin-like growth factor binding protein-3 (IGFBP3). Notably, inhibitors of either HOXB4, RUNX1, or IGFBP3 could reverse the oncogenic activity mediated by circ_0044362. Collectively, our findings reveal the involvement of the circ_0044362/HOXB4 pathway in ovarian cancer progression and provide potential therapeutic strategies for ovarian cancer treatment.

Dysregulated circular RNA and long non-coding RNA-Mediated regulatory competing endogenous RNA networks (ceRNETs) in ovarian and cervical cancers: A non-coding RNA-Mediated mechanism of chemotherapeutic resistance with new emerging clinical capacities

Cervical cancer (CC) and ovarian cancer (OC) are among the most common gynecological cancers with significant mortality in women, and their incidence is increasing. In addition to the prominent role of the malignant aspect of these cancers in cancer-related women deaths, chemotherapy drug resistance is a major factor that contributes to their mortality and presents a clinical obstacle. Although the exact mechanisms behind the chemoresistance in these cancers has not been revealed, accumulating evidence points to the dysregulation of non-coding RNAs (ncRNAs), particularly long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as key contributors. These ncRNAs perform the roles of regulators of signaling pathways linked to tumor formation and chemoresistance. Strong data from various recent studies have uncovered that the main mechanism of these ncRNAs in the induction of chemoresistance of CC and OC is done through a dysregulated miRNA sponge activity as competing endogenous RNA (ceRNA) in the competing endogenous RNA networks (ceRNETs), where a miRNA regulating a messenger RNA (mRNA) is trapped, thereby removing its inhibitory effect on the desired mRNA. Understanding these mechanisms is essential to enhancing treatment outcomes and managing the problem of drug resistance. This review provides a comprehensive overview of lncRNA- and circRNA-mediated ceRNETs as the core process of chemoresistance against the commonly used chemotherapeutics, including cisplatin, paclitaxel, oxaliplatin, carboplatin, and docetaxel in CC and OC. Furthermore, we highlight the clinical potential of these ncRNAs serving as diagnostic indicators of chemotherapy responses and therapeutic targets.

Cinobufagin regulates the microRNA-149-3p/AFF4 axis to affect the proliferation and apoptosis of cisplatin-resistant ovarian cancer cells

Although cinobufagin has been demonstrated to inhibit the growth of various malignant tumors, its functional role in ovarian cancer remains unclear. In light of this, the present study aims to thoroughly investigate the effects of cinobufagin on ovarian cancer progression and elucidate its underlying molecular mechanisms, thereby providing novel insights into future therapeutic strategies. A2780/DDP, a cisplatin-resistant cell line for ovarian cancer, was treated with gradient doses of cinobufagin. The microRNA-149-3p and AFF4 binding sites were predicted by bioinformatics. In cisplatin-resistant ovarian cancer cells, microRNA-149-3p and AFF4 expression were detected using qRT-PCR, and the binding association between microRNA-149-3p and AFF4 was confirmed by dual-luciferase and RIP assays. Cell viability was assessed using the CCK-8 test, cell proliferation was identified using the EdU assay and colony formation, and cell apoptosis was identified using flow cytometry. The results showed that cinobufagin inhibited the proliferation and promoted apoptosis of cisplatin-resistant ovarian cancer cells. microRNA-149-3p was highly expressed in cisplatin-resistant ovarian cancer cells, while AFF4 was lowly expressed in these cells. Overexpression of microRNA-149-3p promoted the proliferation and inhibited the apoptosis of cisplatin-resistant ovarian cancer cells, which was reversed by the addition of cinobufagin. Overexpression of AFF4 suppressed proliferation and promoted apoptosis of cisplatin-resistant ovarian cancer cells. MicroRNA-149-3p repressed AFF4 expression, and partial attenuation of the effects of AFF4 overexpression on cell phenotype was observed when microRNA-149-3p was overexpressed. In conclusion,cinobufagin regulated microRNA-149-3p/AFF4 axis to inhibit proliferation of ovarian cancer cells and promote cell apoptosis. Targeting the microRNA-149-3p/AFF4 axis with cinobufagin could represent a novel therapeutic strategy for ovarian cancer.

Tumor-associated macrophages remodel the suppressive tumor immune microenvironment and targeted therapy for immunotherapy

Despite the significant advances in the development of immune checkpoint inhibitors (ICI), primary and acquired ICI resistance remains the primary impediment to effective cancer immunotherapy. Residing in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) play a pivotal role in tumor progression by regulating diverse signaling pathways. Notably, accumulating evidence has confirmed that TAMs interplay with various cellular components within the TME directly or indirectly to maintain the dynamic balance of the M1/M2 ratio and shape an immunosuppressive TME, consequently conferring immune evasion and immunotherapy tolerance. Detailed investigation of the communication network around TAMs could provide potential molecular targets and optimize ICI therapies. In this review, we systematically summarize the latest advances in understanding the origin and functional plasticity of TAMs, with a focus on the key signaling pathways driving macrophage polarization and the diverse stimuli that regulate this dynamic process. Moreover, we elaborate on the intricate interplay between TAMs and other cellular constituents within the TME, that is driving tumor initiation, progression and immune evasion, exploring novel targets for cancer immunotherapy. We further discuss current challenges and future research directions, emphasizing the need to decode TAM-TME interactions and translate preclinical findings into clinical breakthroughs. In conclusion, while TAM-targeted therapies hold significant promise for enhancing immunotherapy outcomes, addressing key challenges-such as TAM heterogeneity, context-dependent plasticity, and therapeutic resistance-remains critical to achieving optimal clinical efficacy.

Immunomodulatory role of RNA modifications in sex hormone-dependent cancers

Recent studies have identified that RNA epigenetic modifications, including m6A, m1A, m5C, etc, play pivotal roles in tumor progression. These modifications influence mRNA stability, RNA processing, translational efficiency, and decoding precision. However, comprehensive reviews detailing the connection between m6A RNA modifications and hormone-dependent cancers in both male and female populations remain scarce(breast cancer, ovarian cancer, and endometrial cancer, prostate cancer). In this article, we explore the cellular and molecular roles of various RNA modifications alongside the key elements of the tumor microenvironment. We examine how these RNA modifications influence the development of hormone-dependent cancers through their impact on immune mechanisms. By enhancing our understanding of the function of RNA modifications within the immune systems of four specific tumors, we offer fresh insights for their potential applications in diagnosis and treatment.

CircRNAs in the tumor microenvironment: new frontiers in cancer progression and therapy

The tumor microenvironment (TME), a dynamic ecosystem which including immune cells, cancer-associated fibroblasts (CAFs), endothelial cells, pericytes and acellular components, is orchestrating cancer progression through crosstalk between malignant cells and stromal components and increasingly recognized as a therapeutic frontier. Within this intricate network, circular RNAs (circRNAs) have emerged as pivotal regulators due to their unique covalently closed structures, which confer exceptional stability and multifunctional capabilities. This regulation is mediated through multiple mechanisms, such as acting as microRNA (miRNA) sponges, interacting with proteins, and, in certain instances, encoding functional peptides. The interaction between circRNAs and the TME not only affects cancer growth and metastasis but also influences immune evasion and therapeutic resistance. Elucidating the mechanisms by which circRNAs orchestrate these interactions is essential for identifying novel diagnostic biomarkers and developing effective therapeutic strategies. Such insights are expected to bridge gaps in current cancer biology, offering promising avenues for precision oncology and ultimately improving clinical outcomes for cancer patients.

Oligonucleotide-Based Modulation of Macrophage Polarization: Emerging Strategies in Immunotherapy

BACKGROUND

Recent advances in immunotherapy have spotlighted macrophages as central mediators of disease treatment. Their polarization into pro‑inflammatory (M1) or anti‑inflammatory (M2) states critically influences outcomes in cancer, autoimmunity, and chronic inflammation. Oligonucleotides have emerged as highly specific, scalable, and cost‑effective agents for reprogramming macrophage phenotypes.

OBJECTIVE

To review oligonucleotide strategies-including ASOs, siRNAs, miRNA mimics/inhibitors, and aptamers-for directing macrophage polarization and their therapeutic implications.

REVIEW SCOPE

We examine key signaling pathways governing M1/M2 phenotypes, describe four classes of oligonucleotides and their mechanisms, and highlight representative preclinical and clinical applications.

KEY INSIGHTS

Agents such as AZD9150, MRX34, and AS1411 demonstrate macrophage reprogramming in cancer, inflammation, and infection models. Advances in ligand‑conjugated nanoparticles and chemical modifications improve delivery and stability, yet immunogenicity, off‑target effects, and formulation challenges remain significant barriers.

FUTURE PERSPECTIVES

Optimizing delivery platforms, enhancing molecular stability, and rigorous safety profiling are critical. Integration with emerging modalities-such as engineered CAR‑macrophages-will enable precise, disease‑specific interventions, and advance oligonucleotide‑guided macrophage modulation toward clinical translation.

A Novel Neutrophil Extracellular Trap Signature Predicts Patient Chemotherapy Resistance and Prognosis in Lung Adenocarcinoma

Chemoresistance is a key obstacle in the long-term survival of patients with locally and advanced lung adenocarcinoma (LUAD). This study used bioinformatic analysis to reveal the chemoresistance of gene-neutrophil extracellular traps (NETs) associated with LUAD. RNA sequencing data and LUAD expression patterns were obtained from the Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, respectively. The GeneCards database was used to identify NETosis-related genes (NRGs). To identify hub genes with significant and consistent expression, differential analysis was performed using the TCGA-LUAD and GEO datasets. LUAD subtypes were determined based on these hub genes, followed by prognostic analysis. Immunological scoring and infiltration analysis were conducted using NETosis scores (N-scores) derived from the TCGA-LUAD dataset. A clinical prognostic model was established and analyzed, and its clinical applications explored. Twenty-two hub genes were identified, and consensus clustering was used to identify two subgroups based on their expression levels. The Kaplan-Meier (KM) curves demonstrated statistically significant differences in prognosis between the two LUAD subtypes. Based on the median score, patients were further divided into high and low N-score groups, and KM curves showed that the N-scores were more precise at predicting the prognosis of patients with LUAD for overall survival (OS). Immunological infiltration analysis revealed significant differences in the abundances of 10 immune cell infiltrates between the high and low N-score groups. Risk scores indicated significant differences in prognosis between the two extreme score groups. The risk scores for the prognostic model also indicated significant differences between the two groups. The results provide new insights into NETosis-related differentially expressed genes (NRDEGs) associated with chemotherapy resistance in patients with LUAD. The established prognostic model is promising and could help with clinical applications to evaluate patient survival and therapeutic efficiency.

Recent advances in the role of circRNA in cisplatin resistance in tumors

Cancer remains a major threat to human health, with chemotherapy serving as one of the main treatment strategies to alleviate patient suffering. However, prolonged chemotherapy often leads to the development of drug resistance, complicating treatment outcomes. Cisplatin, a commonly utilized chemotherapeutic agent, demonstrates efficacy against a range of cancers but frequently encounters resistance, posing a significant challenge in tumor management and prognosis. Drug resistance not only facilitates tumor progression but also reduces survival rates, highlighting the urgent need for innovative strategies to overcome this issue. In recent years, non-coding RNAs, particularly circular RNAs (circRNAs), have gained attention in cancer therapy due to their stability and specificity. Moreover, an increasing number of studies have reported that circRNAs are involved in cisplatin resistance across various types of cancer. This paper primarily reviews the mechanisms and roles of circRNA in mediating cisplatin resistance over the past 3 years. These findings highlight circRNAs as promising therapeutic targets for overcoming cancer drug resistance.

Cisplatin reduces immunosuppression caused by tumor-associated macrophages through downregulating CD47-SIRPα signaling in glioblastoma

The poor prognosis of glioblastoma (GBM) is partly attributed to the immunosuppressive microenvironment. The combination of standard temozolomide and other chemotherapy drugs can significantly enhance the therapeutic effect by reshaping the immune microenvironment. Cisplatin treatment induces immunogenic cell death in tumor cells, stimulating an immune response. Here, we investigated the immune-activating effect of cisplatin on tumor-associated macrophages (TAMs). The therapeutic benefit of temozolomide plus cisplatin was showed in a murine model of GBM, accompanied by the inhibition of tumor growth and enhancement of pro-inflammatory activation of TAMs. Furthermore, cisplatin treatment downregulated the expression of CD47 in glioma stem cells, SIRPα, and IL-6 in TAMs, thus promoting M1-like polarization of TAMs to enhance an immune-activating tumor microenvironment. Mechanically, cisplatin decreases the production of lactic acid by downregulating LDHA expression. A low level of lactate reduces histone H3K18 lactylation on the CD47 and IL-6 promoters, thereby suppressing gene transcription. Our study reveals a new mechanism by which cisplatin remodels the immune tumor microenvironment, suggesting that combining temozolomide with cisplatin chemotherapy may be a new treatment option for GBM.

The role of macrophage polarization in ovarian cancer: from molecular mechanism to therapeutic potentials

Ovarian cancer (OC) remains the most lethal gynecological malignancy, primarily due to its late-stage diagnosis, frequent recurrence, and resistance to conventional chemotherapy. A critical factor contributing to OC's aggressiveness is the tumor microenvironment (TME), particularly the presence and polarization of tumor-associated macrophages (TAMs). TAMs, often skewed toward an immunosuppressive M2-like phenotype, facilitate tumor growth, angiogenesis, metastasis, and resistance to therapy. This comprehensive review delves into the multifaceted regulation of macrophage polarization in OC, highlighting key molecular pathways such as PTEN loss, Wnt/β-catenin signaling, NF-κB, Myc, STAT3, and JNK, among others. Additionally, it explores the role of chemokines, non-coding RNAs, and various proteins in modulating TAM phenotypes. Emerging evidence underscores the significance of extracellular vesicles (EVs) and ovarian cancer stem cells (CSCs) in promoting M2 polarization, thereby enhancing tumor progression and therapy resistance. The review also identifies critical biomarkers associated with macrophage polarization, including CD163, LILRB1, MUC2, and others, which hold prognostic and therapeutic potential. Therapeutic strategies targeting TAMs are extensively discussed, encompassing oncolytic viruses, engineered EVs, immunotherapies, nanoparticles, targeted therapies, and natural products. These approaches aim to reprogram TAMs from a pro-tumorigenic M2 state to an anti-tumorigenic M1 phenotype, thereby enhancing immune responses and overcoming resistance to treatments such as chemotherapy and immune checkpoint inhibitors. Furthermore, the review addresses the interplay between macrophage polarization and therapy resistance, emphasizing the need for novel interventions to modulate the TME effectively. By synthesizing current knowledge on macrophage polarization in ovarian cancer, this study underscores the potential of targeting TAMs to improve clinical outcomes and personalize treatment strategies for OC patients. Continued research in this domain is essential to develop robust therapeutic frameworks that can mitigate the immunosuppressive TME and enhance the efficacy of existing and novel cancer therapies.

The interaction between IL-33 and TRIM28 in the regulation of macrophage polarization in an ST2-independent manner

The tumor microenvironment provides optimal condition for the growth of ovarian cancer. Macrophages display a highly functional plasticity to respond various signals. Switching macrophages' phenotype is a potential therapeutic strategy for the treatment of cancer. We used RNA-sequencing(RNA-Seq) and Chromatin immunoprecipitation-sequencing(ChIP-Seq) analyses in bone-marrow-derived macrophages (BMDMs) from wild-type (WT) and its receptor interleukin-1 receptor like-1 (IL1RL1 or ST2) knockout(ST2-/-) mice revealed that the interaction between IL-33 and TRIM28, which plays an antioxidant role, regulates glycolysis in BMDMs by promoting the PI3K/Akt pathway in ST2-independent manner, thereby reducing M2 polarization of macrophages is a way to inhibit ovarian cancer growth.

Hyperinflammatory repolarisation of ovarian cancer patient macrophages by anti-tumour IgE antibody, MOv18, restricts an immunosuppressive macrophage:Treg cell interaction

Ovarian cancer is the most lethal gynaecological cancer and treatment options remain limited. In a recent first-in-class Phase I trial, the monoclonal IgE antibody MOv18, specific for the tumour-associated antigen Folate Receptor-α, was well-tolerated and preliminary anti-tumoural activity observed. Pre-clinical studies identified macrophages as mediators of tumour restriction and pro-inflammatory activation by IgE. However, the mechanisms of IgE-mediated modulation of macrophages and downstream tumour immunity in human cancer remain unclear. Here we study macrophages from patients with epithelial ovarian cancers naive to IgE therapy. High-dimensional flow cytometry and RNA-seq demonstrate immunosuppressive, FcεR-expressing macrophage phenotypes. Ex vivo co-cultures and RNA-seq interaction analyses reveal immunosuppressive associations between patient-derived macrophages and regulatory T (Treg) cells. MOv18 IgE-engaged patient-derived macrophages undergo pro-inflammatory repolarisation ex vivo and display induction of a hyperinflammatory, T cell-stimulatory subset. IgE reverses macrophage-promoted Treg cell induction to increase CD8+ T cell expansion, a signature associated with improved patient prognosis. On-treatment tumours from the MOv18 IgE Phase I trial show evidence of this IgE-driven immune signature, with increased CD68+ and CD3+ cell infiltration. We demonstrate that IgE induces hyperinflammatory repolarised states of patient-derived macrophages to inhibit Treg cell immunosuppression. These processes may collectively promote immune activation in ovarian cancer patients receiving IgE therapy.

IGF2BP2: an m6A reader that affects cellular function and disease progression

Insulin-like growth factor 2 messenger RNA (mRNA)-binding protein 2 (IGF2BP2) is a widely studied N6-methyladenosine (m6A) modification reader, primarily functioning to recognize and bind to m6A modification sites on the mRNA of downstream target genes, thereby enhancing their stability. Previous studies have suggested that the IGF2BP2-m6A modification plays an essential role in cellular functions and the progression of various diseases. In this review, we focus on summarizing the molecular mechanisms by which IGF2BP2 enhances the mRNA stability of downstream target genes through m6A modification, thereby regulating cell ferroptosis, epithelial-mesenchymal transition (EMT), stemness, angiogenesis, inflammatory responses, and lipid metabolism, ultimately affecting disease progression. Additionally, we update the related research progress on IGF2BP2. This article aims to elucidate the effects of IGF2BP2 on cell ferroptosis, EMT, stemness, angiogenesis, inflammatory responses, and lipid metabolism, providing a new perspective for a comprehensive understanding of the relationship between IGF2BP2 and cell functions such as ferroptosis and EMT, as well as the potential for targeted IGF2BP2 therapy for tumors and other diseases.

Effects of circulating RNAs on tumor metabolism in lung cancer (Review)

During the development and progression of lung cancer, cell metabolism function is altered. Thus, cells rely on aerobic glycolysis and abnormal lipid and amino acid metabolism to obtain energy and nutrients for growth, proliferation and drug resistance. Circular RNAs (circRNAs), a class of non-coding RNAs, serve important biological roles in the growth and development of tumors. Functionally, circRNAs act as molecular sponges that absorb microRNAs (miRNAs) and RNA-binding proteins and as protein scaffolds that regulate gene transcription and translation through the maintenance of mRNA stability. In addition, circRNAs are important regulators of tumor metabolism and promote tumor progression through mediating tumor cell proliferation, metastasis and the induction of chemoresistance. Results of previous studies reveal that circRNAs may serve a key role in regulating tumor metabolic processes in lung cancer, through miRNA sponging and alternative mechanisms. Thus, circRNAs demonstrate potential as therapeutic targets for lung cancer. The present study aimed to review the effects of circRNAs on lung cancer cell metabolism and provide novel insights into the clinical treatment of lung cancer. The present review may also provide a novel theoretical basis for the development of lung cancer drug targets.

CpG-Based Nanovaccines Enhance Ovarian Cancer Immune Response by Gbp2-Mediated Remodeling of Tumor-Associated Macrophages

CpG oligodeoxynucleotides (CpG), as an immunoadjuvant, can facilitate the transformation of tumor-associated macrophages (TAMs)into tumoricidal M1 macrophages. However, the accumulation of free CpG in tumor tissues remains a substantial challenge. To address this, a nanovaccine (PLGA-CpG@ID8-M) is engineered by encapsulating CpG within PLGA using ID8 ovarian cancer cell membranes (ID8-M). This nanovaccine demonstrates remarkable efficacy in reprogramming TAMs in ovarian cancer and significantly extends survival in ID8-bearing mice. Notably, these findings indicate that the nanovaccine can also mitigate chemotherapy-induced immunosuppression by increasing the proportion of M1-like TAMs and reducing the expression of CD47 on tumor cells, thereby achieving a synergistic effect in tumor immunotherapy. Mechanistically, through transcriptome sequencing (RNA-seq), single-cell RNA sequencing (scRNA-seq), and mass spectrometry-based proteomics, it is elucidated that the nanovaccine enhances the expression of Gbp2 and promotes the recruitment of Pin1, which activates the NFκB signaling pathway, leading to the M1 polarization of TAMs. Furthermore, macrophages with elevated Gbp2 expression significantly inhibit tumor growth in both ID8 ovarian cancer and 4T1 breast cancer models. Conversely, targeting Gbp2 diminishes the antitumor efficacy of the nanovaccine in vivo. This study offers an innovative approach to immunotherapy and elucidates a novel mechanism (Gbp2-Pin1-NFκB pathway) for remodeling TAMs.

Circular RNAs modulate cancer drug resistance: advances and challenges

Acquired drug resistance is a main factor contributing to cancer therapy failure and high cancer mortality, highlighting the necessity to develop novel intervention targets. Circular RNAs (circRNAs), an abundant class of RNA molecules with a closed loop structure, possess characteristics including high stability, which provide unique advantages in clinical application. Growing evidence indicates that aberrantly expressed circRNAs are associated with resistance against various cancer treatments, including targeted therapy, chemotherapy, radiotherapy, and immunotherapy. Therefore, targeting these aberrant circRNAs may offer a strategy to improve the efficiency of cancer therapy. Herein, we present a summary of the most recently studied circRNAs and their regulatory roles on cancer drug resistance. With the advances in artificial intelligence (AI)-based bioinformatics algorithms, circRNAs could emerge as promising biomarkers and intervention targets in cancer therapy.

Organoid models of ovarian cancer: resolving immune mechanisms of metabolic reprogramming and drug resistance

Metabolic reprogramming is a hallmark of ovarian cancer, enabling tumor progression, immune evasion and drug resistance. The tumor microenvironment (TME) further shapes metabolic adaptations, enabling cancer cells to withstand hypoxia and nutrient deprivation. While organoid models provide a physiologically relevant platform for studying these processes, they still lack immune and vascular components, limiting their ability to fully recapitulate tumor metabolism and drug responses. In this study, we investigated the key metabolic mechanisms involved in ovarian cancer progression, focusing on glycolysis, lipid metabolism and amino acid metabolism. We integrated metabolomic analyses and drug sensitivity assays to explore metabolic-TME interactions using patient-derived, adult stem cell-derived and iPSC-derived organ tissues. Among these, we found that glycolysis, lipid metabolism and amino acid metabolism play a central role in tumor progression and chemotherapy resistance. We identified methylglyoxal (MGO)-mediated BRCA2 dysfunction as a driver of immune escape, a role for sphingolipid signaling in tumor proliferation and a role for kynurenine metabolism in CD8+ T cell suppression. In addition, PI3K/AKT/mTOR and Wnt/β-catenin pathways promote chemoresistance through metabolic adaptation. By elucidating the link between metabolic reprogramming and immune evasion, this study identifies key metabolic vulnerabilities and potential drug targets in ovarian cancer. Our findings support the development of metabolically targeted therapies and increase the utility of organoid-based precision medicine models.

Tumor microenvironment: recent advances in understanding and its role in modulating cancer therapies

Tumor microenvironment (TME) denotes the non-cancerous cells and components presented in the tumor, including molecules produced and released by them. Interactions between cancer cells, immune cells, stromal cells, and the extracellular matrix within the TME create a dynamic ecosystem that can either promote or hinder tumor growth and spread. The TME plays a pivotal role in either promoting or inhibiting tumor growth and dissemination, making it a critical factor to consider in the development of effective cancer therapies. Understanding the intricate interplay within the TME is crucial for devising effective cancer therapies. Combination therapies involving inhibitors of immune checkpoint blockade (ICB), and/or chemotherapy now offer new approaches for cancer therapy. However, it remains uncertain how to best utilize these strategies in the context of the complex tumor microenvironment. Oncogene-driven changes in tumor cell metabolism can impact the TME to limit immune responses and present barriers to cancer therapy. Cellular and acellular components in tumor microenvironment can reprogram tumor initiation, growth, invasion, metastasis, and response to therapies. Components in the TME can reprogram tumor behavior and influence responses to treatments, facilitating immune evasion, nutrient deprivation, and therapeutic resistance. Moreover, the TME can influence angiogenesis, promoting the formation of blood vessels that sustain tumor growth. Notably, the TME facilitates immune evasion, establishes a nutrient-deprived milieu, and induces therapeutic resistance, hindering treatment efficacy. A paradigm shift from a cancer-centric model to a TME-centric one has revolutionized cancer research and treatment. However, effectively targeting specific cells or pathways within the TME remains a challenge, as the complexity of the TME poses hurdles in designing precise and effective therapies. This review highlights challenges in targeting the tumor microenvironment to achieve therapeutic efficacy; explore new approaches and technologies to better decipher the tumor microenvironment; and discuss strategies to intervene in the tumor microenvironment and maximize therapeutic benefits.

Precision Medicine in High-Grade Serous Ovarian Cancer: Targeted Therapies and the Challenge of Chemoresistance

The poor prognosis for high-grade serous ovarian cancer (HGSOC), the dominant subtype of ovarian cancer, reflects its aggressive nature, late diagnosis, and the highest mortality rate among all gynaecologic cancers. Apart from late diagnosis, the main reason for the poor prognosis and its unsuccessful treatment is primarily the emergence of chemoresistance to carboplatin. Although there is a good response to primary treatment, the disease recurs in 80% of cases, at which point it is largely resistant to carboplatin. The introduction of novel targeted therapies in the second decade of the 21st century has begun to transform the treatment of HGSOC, although their impact on overall survival remains unsatisfactory. Targeting the specific pathways known to be abnormally activated in HGSOC is especially difficult due to the molecular diversity of its subtypes. Moreover, a range of molecular changes are associated with acquired chemoresistance, e.g., reversion of BRCA1 and BRCA2 germline alleles. In this review, we examine the advantages and disadvantages of approved targeted therapies, including bevacizumab, PARP inhibitors (PARPis), and treatments targeting cells with neurotrophic tyrosine receptor kinase (NTRK), B-rapidly accelerated fibrosarcoma (BRAF), and rearranged during transfection (RET) gene alterations, as well as antibody-drug conjugates. Additionally, we explore promising new targets under investigation in ongoing clinical trials, such as immune checkpoint inhibitors, anti-angiogenic agents, phosphatidylinositol-3-kinase (PI3K) inhibitors, Wee1 kinase inhibitors, and ataxia telangiectasia and Rad3-related protein (ATR) inhibitors for platinum-resistant disease. Despite the development of new targeted therapies, carboplatin remains the fundamental medicine in HGSOC therapy. The correct choice of treatment strategy for better survival of patients with advanced HGSOC should therefore include a prediction of patients' risks of developing chemoresistance to platinum-based chemotherapy. Moreover, effective targeted therapy requires the selection of patients who are likely to derive clinical benefit while minimizing potential adverse effects, underscoring the essence of precision medicine.

Periplocin improves the sensitivity of oxaliplatin-resistant hepatocellular carcinoma cells by inhibiting M2 macrophage polarization

The aim of this research was to investigate the impact of periplocin (PPLN) on oxaliplatin (OXA) resistance in hepatocellular carcinoma (HCC) cells and offer insights for improving clinical treatment of HCC. The IC50 value of HCC cell lines against OXA was detected by the CCK-8 assay, and an OXA-resistant HepG2 cell line (HepG2/OXA) was constructed. THP-1 cells were induced into M1 or M2 macrophages, and M2 macrophage-conditioned medium (M2-CM) was prepared. M1 and M2 macrophage polarization were detected using RT-qPCR and flow cytometry. CCK-8, EdU staining, clone formation assay, flow cytometry, and western blotting were used to assess the proliferation and apoptosis of HepG2/OXA cells treated with PPLN and M2-CM. Additionally, a nude mouse subcutaneous graft tumor model was constructed. PPLN enhanced the sensitivity of HepG2/OXA cells to OXA, reduced their clone-forming ability, and promoted their apoptosis. Notably, PPLN hindered M0 macrophage polarization to M2 macrophages, while M1 polarization remained unaffected. The proliferation-inhibiting and apoptosis-promoting effects of OXA+PPLN on HepG2/OXA cells were significantly attenuated by the addition of M2-CM, suggesting that PPLN improves the OXA sensitivity of HepG2/OXA cells by hindering M2 macrophage polarization. Furthermore, PPLN inhibited M2 macrophage polarization and improved the OXA sensitivity of HepG2/OXA cells in vivo. In conclusion, PPLN inhibited the proliferation of HepG2/OXA cells, promoted their apoptosis, and inhibited M2 macrophage polarization both in vivo and in vitro, which in turn enhanced the OXA sensitivity of HepG2/OXA cells.

Circular RNAs as key regulators in cancer hallmarks: New progress and therapeutic opportunities

Circular RNAs (circRNAs) have emerged as critical regulators in cancer biology, contributing to various cancer hallmarks, including cell proliferation, apoptosis, metastasis, and drug resistance. Defined by their covalently closed loop structure, circRNAs possess unique characteristics like high stability, abundance, and tissue-specific expression. These non-coding RNAs function through mechanisms such as miRNA sponging, interactions with RNA-binding proteins (RBPs), and modulating transcription and splicing. Advances in RNA sequencing and bioinformatics tools have enabled the identification and functional annotation of circRNAs across different cancer types. Clinically, circRNAs demonstrate high specificity and sensitivity in samples, offering potential as diagnostic and prognostic biomarkers. Additionally, therapeutic strategies involving circRNA mimics, inhibitors, and delivery systems are under investigation. However, their precise mechanisms remain unclear, and more clinical evidence is needed regarding their roles in cancer hallmarks. Understanding circRNAs will pave the way for novel diagnostic and therapeutic approaches, potentially improving patient outcomes.

Hsa_circ_0087784 enhances non-small cell lung cancer progression via the miR-576-5p/CDCA4 axis

BACKGROUND

Circular RNAs (circRNAs) belong to a family of covalently closed single-stranded RNAs that have been implicated in cancer progression. Previous studies have reported that hsa_circ_0087784 was abnormally expressed in breast cancer. However, the role of hsa_circ_0087784 in non-small cell lung cancer (NSCLC) is unknown.

METHODS

Here, we used RT-qPCR and FISH to examine hsa_circ_0087784 expression in NSCLC cells and tissue samples. The dual-luciferase reporter assay was used to identify downstream targets of hsa_circ_0087784. Transwell migration, 5-ethynyl-2´-deoxyuridine, and CCK-8 assays were used to examine migration and proliferation. Tumorigenesis and metastasis assays were used to determine the role of hsa_circ_0087784 in NSCLC progression in a mouse tumor xenograft model in vivo.

RESULTS

We found that hsa_circ_0087784 was expressed at significantly high levels in NSCLC tissue samples and cell lines. Downregulation of hsa_circ_0087784 suppressed NSCLC cellular proliferation, as well as migration. Our dual-luciferase reporter assay revealed that miR-576-5p and CDCA4 were downstream targets of hsa_circ_0087784. CDCA4 overexpression or miR-576-5p suppression reversed the effects of hsa_circ_0087784 silencing on NSCLC cell migration, and EMT-related protein expression levels.

CONCLUSION

Our findings suggested that downregulation of hsa_circ_0087784 inhibited NSCLC metastasis and progression through the regulation of CDCA4 expression and miR-576-5p sponging.

Identifying macrophage-associated subtypes in patients with serous ovarian cancer and exploring potential personalized therapeutic drugs using combined single-cell and bulk RNA sequencing omics

Purpose

We aimed to analyze the sensitivity of patients to chemotherapy drugs and actively explore potential new intervention targets, providing an essential reference for personalized treatment.

Methods

Candidate markers with significant differential expression in macrophages were identified by analyzing gene expression at the single-cell level. A weighted gene co-expression network (WGCN) was constructed on the GSE26712 dataset to explore the modules most relevant to macrophages. Differentially expressed genes for specific markers were identified. A multi-factor regulatory network was constructed based on single-cell dataset markers screening, differentially expressed genes, and genes commonly present in WGCNA modules. Different macrophage subtypes were identified using this network. Machine learning was used to filter and predict the markers' drug sensitivity, and the potential therapeutic compounds for specific markers were screened.

Results

We identified 14 and 17 of M1 and M2 macrophage candidate markers, respectively. In the multi-factor regulatory network of M1 macrophages, 6 out of 14 markers recognized 159 transcription factors (TFs) and 48 micro RNAs (miRNAs), whereas 13 of 17 markers recognized 191 TFs and 182 miRNAs in the multi-factor regulatory network of M2 macrophages. Filtering of the identified differentially expressed genes using random forests yielded 15 M1 and M2 macrophage-specific markers. Drug sensitivity prediction analysis and in vitro experiments revealed the close association of these markers with common chemotherapy drug sensitivity.

Conclusion

We identified specific M1 and M2 macrophage markers and found potential therapeutic compounds (dasatinib and afatinib) in these specific markers. These potential therapeutic compounds provide insight into the underlying mechanisms of serous ovarian cancer (OC) and inspire more effective treatment methods.

TAM-derived exosomal miR-589-3p accelerates ovarian cancer progression through BCL2L13

BACKGROUND

Tumor-associated macrophages (TAM) are critical elements of intercellular communication in tumor microenvironment (TME), and exosomes are key mediators between tumor cells and the TME. According to previous reports, miRNAs exert a pivotal role in ovarian cancer (OC) development. The purpose of this work was to explore the function of TAM-derived exosomal miR-589-3p in OC development and elucidate the underlying molecular mechanisms.

METHODS

First, peripheral blood mononuclear cells (PBMC) were treated with IL-4 and IL-13 to polarize them into M2-type macrophages. Exosomes were separated from M2-type macrophages, and the physical properties of exosomes were evaluated using transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA). Next, quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was applied to examine the expression of relevant genes. Subsequently, Targetscan and miRDB were utilized to predict miR-589-3p target genes, and then the interaction between miR-589-3p and BCL2L13 was verified by dual luciferase assay and RNA Binding Protein Immunoprecipitation (RIP) assay. Finally, Cell Counting Kit-8 (CCK-8) and flow cytometry experiments were employed to explore the changes in the proliferative and apoptotic abilities of OC cells.

RESULTS

In this research, we demonstrated that TAM-derived exosomes facilitated OC cell proliferation and suppressed OC cell apoptosis. Then, qRT-PCR results indicated that miR-589-3p were markedly elevated after co-culture of TAM-derived exosomes with OC cells. In addition, we discovered that miR-589-3p was bound to BCL-2-like protein 13 (BCL2L13), which was confirmed through luciferase assay and RIP assay. Furthermore, functional analysis displayed that TAM-derived exosomes treated with miR-589-3p inhibitor attenuated the promotion of OC cell progression by exosomes.

CONCLUSION

TAM-derived exosomal miR-589-3p enhanced OC progression through BCL2L13, which offers a novel for OC therapy.

Circular RNAs in cancer

Circular RNA (circRNA), a subtype of noncoding RNA, has emerged as a significant focus in RNA research due to its distinctive covalently closed loop structure. CircRNAs play pivotal roles in diverse physiological and pathological processes, functioning through mechanisms such as miRNAs or proteins sponging, regulation of splicing and gene expression, and serving as translation templates, particularly in the context of various cancers. The hallmarks of cancer comprise functional capabilities acquired during carcinogenesis and tumor progression, providing a conceptual framework that elucidates the nature of the malignant transformation. Although numerous studies have elucidated the role of circRNAs in the hallmarks of cancers, their functions in the development of chemoradiotherapy resistance remain unexplored and the clinical applications of circRNA-based translational therapeutics are still in their infancy. This review provides a comprehensive overview of circRNAs, covering their biogenesis, unique characteristics, functions, and turnover mechanisms. We also summarize the involvement of circRNAs in cancer hallmarks and their clinical relevance as biomarkers and therapeutic targets, especially in thyroid cancer (TC). Considering the potential of circRNAs as biomarkers and the fascination of circRNA-based therapeutics, the "Ying-Yang" dynamic regulations of circRNAs in TC warrant vastly dedicated investigations.

Mechanisms and therapeutic implications of gene expression regulation by circRNA-protein interactions in cancer

Circular RNAs (circRNAs) have garnered substantial attention due to their distinctive circular structure and gene regulatory functions, establishing them as a significant class of functional non-coding RNAs in eukaryotes. Studies have demonstrated that circRNAs can interact with RNA-binding proteins (RBPs), which play crucial roles in tumorigenesis, metastasis, and drug response in cancer by influencing gene expression and altering the processes of tumor initiation and progression. This review aims to summarize the recent advances in research on circRNA-protein interactions (CPIs) and discuss the functions and mode of action of CPIs at various stages of gene expression, including transcription, splicing, translation, and post-translational modifications in the context of cancer. Additionally, we explore the role of CPIs in tumor drug resistance to gain a deeper understanding of their potential applications in the development of new anti-cancer therapeutic approaches.

Novel insights into the interaction between IGF2BPs and ncRNAs in cancers

Insulin-like growth factor II mRNA-binding proteins (IGF2BPs), a family of RNA-binding proteins, are pivotal in regulating RNA dynamics, encompassing processes such as localization, metabolism, stability, and translation through the formation of ribonucleoprotein complexes. First identified in 1999 for their affinity to insulin-like growth factor II mRNA, IGF2BPs have been implicated in promoting tumor malignancy behaviors, including proliferation, metastasis, and the maintenance of stemness, which are associated with unfavorable outcomes in various cancers. Additionally, non-coding RNAs (ncRNAs), particularly long non-coding RNAs, circular RNAs, and microRNAs, play critical roles in cancer progression through intricate protein-RNA interactions. Recent studies, predominantly from 2018 onward, indicate that IGF2BPs can recognize and modulate ncRNAs via N6-methyladenosine (m6A) modifications, enriching the regulatory landscape of RNA-protein interactions in the context of cancer. This review explores the latest insights into the interplay between IGF2BPs and ncRNAs, emphasizing their potential influence on cancer biology.

Knockdown of IGF2BP2 overcomes cisplatin-resistance in lung cancer through downregulating Spon2 gene

BACKGROUND

Cisplatin (DDP) resistance has long posed a challenge in the clinical treatment of lung cancer (LC). Insulin-like growth factor 2 binding protein 2 (IGF2BP2) has been identified as an oncogenic factor in LC, whereas its specific role in DDP resistance in LC remains unclear.

RESULTS

In this study, we investigated the role of IGF2BP2 on DDP resistance in DDP-resistant A549 cells (A549/DDP) in vitro and in a DDP-resistant lung tumor-bearing mouse model in vivo. Additionally, methylated RNA immunoprecipitation sequencing (MeRIP-seq) was conducted to identify the potential mRNAs regulated by IGF2BP2, an N6-methyladenosine (m6A) regulator, in the tumor tissues of mice. Compared to normal tissues, IGF2BP2 levels were increased in LC tissues and in relapsed/resistant LC tissues. Most importantly, IGF2BP2 levels were significantly higher in relapsed/resistant LC tissues than in LC tissues. Significantly, knockdown of IGF2BP2 or DDP treatment inhibited A549 cell viability, migration, and cell cycle progression. Consistently, DDP treatment suppressed the viability and migration and triggered cell cycle arrest in A549/DDP cells in vitro, as well as reduced tumor volume and weight of A549/DDP tumor-bearing mice; meanwhile, the combination of DDP and IGF2BP2 siRNA further significantly inhibited A549/DDP cell growth in vitro and in vivo compared to DDP treatment alone. Furthermore, MeRIP-seq data showed that IGF2BP2 downregulation remarkably elevated m6A levels of spondin 2 (Spon2) and reduced mRNA levels of Spon2 in tumor tissues from A549 tumor-bearing mice. Meanwhile, the combination of DDP and IGF2BP2 siRNA notably reduced Spon2 levels, as well as inhibited the viability and induced apoptosis in A549/DDP cells; however, these effects were reversed by Spon2 overexpression.

CONCLUSION

Collectively, downregulation of IGF2BP2 could overcome DDP resistance in LC through declining the Spon2 gene expression in an m6A-dependent manner. These results may provide a new strategy for overcoming DDP resistance in LC.

The role and research progress of tumor-associated macrophages in cervical cancer

Tumor-associated macrophages (TAMs) are important immune cells in the tumor micro-environment (TME) and play a key role in the occurrence and development of cervical cancer. Besides, targeting TAMs can significantly inhibit cervical cancer tumor growth, invasion, metastasis, and angiogenesis as well as affect immune regulation. This review summarizes the correlation between TAM and tumors, the mechanism of action of TAM in cervical cancer, and the potential application of TAM in the treatment of cervical cancer. Therefore, this study may provide new ideas and targets for the development of further treatment strategies for cervical cancer patients.

Ovarian tumor microenvironment contributes to tumor progression and chemoresistance

Ovarian cancer is one of the deadliest gynecologic cancers affecting the female reproductive tract. This is largely attributed to frequent recurrence and development of resistance to the platinum-based drugs cisplatin and carboplatin. One of the major contributing factors to increased cancer progression and resistance to chemotherapy is the tumor microenvironment (TME). Extracellular signaling from cells within the microenvironment heavily influences progression and drug resistance in ovarian cancer. This is frequently done through metabolic reprogramming, the process where cancer cells switch between biochemical pathways to increase their chances of survival and proliferation. Here, we focus on how crosstalk between components of the TME and the tumor promotes resistance to platinum-based chemotherapy. We highlight the role of cancer-associated fibroblasts, immune cells, adipocytes, and endothelial cells in ovarian tumor progression, invasion, metastasis, and chemoresistance. We also highlight recent advancements in targeting components of the TME as a novel therapeutic avenue to combat chemoresistance in ovarian cancer.

The emerging role of circular RNAs in cisplatin resistance in ovarian cancer: From molecular mechanism to future potential

Ovarian cancer (OC) is the most common cause of death in female cancers. The prognosis of OC is very poor due to delayed diagnosis and identification of most patients in advanced stages, metastasis, recurrence, and resistance to chemotherapy. As chemotherapy with platinum-based drugs such as cisplatin (DDP) is the main treatment in most OC cases, resistance to DDP is an important obstacle to achieving satisfactory therapeutic efficacy. Consequently, knowing the different molecular mechanisms involved in resistance to DDP is necessary to achieve new therapeutic approaches. According to numerous recent studies, non-coding RNAs (ncRNAs) could regulate proliferation, differentiation, apoptosis, and chemoresistance in many cancers, including OC. Most of these ncRNAs are released by tumor cells into human fluid, allowing them to be used as tools for diagnosis. CircRNAs are ncRNA family members that have a role in the initiation, progression, and chemoresistance regulation of various cancers. In the current study, we investigated the roles of several circRNAs and their signaling pathways on OC progression and also on DDP resistance during chemotherapy.

Beyond tumor‑associated macrophages involved in spheroid formation and dissemination: Novel insights for ovarian cancer therapy (Review)

Ovarian cancer (OC) is the most common and deadly malignant tumor of the female reproductive system. When OC cells detach from the primary tumor and enter the ascitic microenvironment, they are present as individual cells or multicellular spheroids in ascites. These spheroids, composed of cancer and non‑malignant cells, are metastatic units and play a crucial role in the progression of OC. However, little is known about the mechanism of spheroid formation and dissemination. Tumor‑associated macrophages (TAMs) in the center of spheroids are key in spheroid formation and metastasis and provide a potential target for OC therapy. The present review summarizes the key biological features of spheroids, focusing on the role of TAMs in spheroid formation, survival and peritoneal metastasis, and the strategies targeting TAMs to provide new insights in treating OC.

The Emerging Role of IGF2BP2 in Cancer Therapy Resistance: From Molecular Mechanism to Future Potential

Tumor resistance is one of the primary reasons for cancer treatment failure, significantly limiting the options and efficacy of cancer therapies. Therefore, overcoming resistance has become a critical factor in improving cancer treatment outcomes. IGF2BP2, as a reader of m6A methylation, plays a pivotal role in the post-transcriptional regulation of RNA through the methylation of m6A sites. It not only contributes to cancer initiation and progression but also plays a key role in tumor drug resistance. This review provides a comprehensive summary of the mechanisms by which IGF2BP2 contributes to therapy resistance, with the aim of improving the efficacy of chemotherapy in cancer treatment. Advancing research in this area is crucial for developing more effective therapies that could significantly improve the quality of life for cancer patients.

Unlocking the potential of extracellular vesicle circRNAs in breast cancer: From molecular mechanisms to therapeutic horizons

Breast cancer remains the leading cause of cancer-related morbidity and mortality among women worldwide, underscoring the urgent need for novel diagnostic and therapeutic strategies. This review explores the emerging roles of circular RNAs (circRNAs) within extracellular vesicles (exosomes) in breast cancer. circRNAs, known for their stability and tissue-specific expression, are aberrantly expressed in breast cancer and regulate critical cellular processes such as proliferation, migration, and apoptosis, positioning them as promising biomarkers. Exosomes facilitate intercellular communication by delivering circRNAs, reflecting the physiological and pathological state of their source cells. This review highlights the multifaceted roles of exosomal circRNAs in promoting tumor growth, metastasis, and drug resistance through their modulation of tumor metabolism, the tumor microenvironment, and immune responses. In particular, we emphasize their contributions to chemotherapy resistance and their potential as both diagnostic markers and therapeutic targets. By synthesizing current research, this review provides novel insights into the clinical applications of exosomal circRNAs, offering a foundation for future studies aimed at improving breast cancer management through non-invasive diagnostics and targeted therapies.

Circular RNAs in programmed cell death: Regulation mechanisms and potential clinical applications in cancer: A review

Circular RNAs (circRNAs) are a novel class of non-coding RNAs with covalently closed structures formed by reverse splicing of precursor mRNAs. The widespread expression of circRNAs across species has been revealed by high-throughput sequencing and bioinformatics approaches, indicating their unique properties and diverse functions including acting as microRNA sponges and interacting with RNA-binding proteins. Programmed cell death (PCD), encompassing various forms such as apoptosis, necroptosis, pyroptosis, autophagy, and ferroptosis, is an essential process for maintaining normal development and homeostasis in the human body by eliminating damaged, infected, and aging cells. Many studies have demonstrated that circRNAs play crucial roles in tumourigenesis and development by regulating PCD in tumor cells, showing that circRNAs have the potential to be biomarkers and therapeutic targets in cancer. This review aims to comprehensively summarize the intricate associations between circRNAs and diverse PCD pathways in tumor cells, which play crucial roles in cancer development. Additionally, this review provides a detailed overview of the underlying mechanisms by which circRNAs modulate various forms of PCD for the first time. The ultimate objective is to offer valuable insights into the potential clinical significance of developing novel strategies based on circRNAs and PCD for cancer diagnosis, prognosis, and treatment.

Decoding the epitranscriptome: a new frontier for cancer therapy and drug resistance

As the role of RNA modification in gene expression regulation and human diseases, the "epitranscriptome" has been shown to be an important player in regulating many physiological and pathological processes. Meanwhile, the phenomenon of cancer drug resistance is becoming more and more frequent, especially in the case of cancer chemotherapy resistance. In recent years, research on relationship between post-transcriptional modification and cancer including drug resistance has become a hot topic, especially the methylation of the sixth nitrogen site of RNA adenosine-m6A (N6-methyladenosine). m6A modification is the most common post-transcriptional modification of eukaryotic mRNA, accounting for 80% of RNA methylation modifications. At the same time, several other modifications of RNA, such as N1-methyladenosine (m1A), 5-methylcytosine (m5C), 3-methylcytosine (m3C), pseudouridine (Ψ) and N7-methylguanosine (m7G) have also been demonstrated to be involved in cancer and drug resistance. This review mainly discusses the research progress of RNA modifications in the field of cancer and drug resistance and targeting of m6A regulators by small molecule modulators, providing reference for future study and development of combination therapy to reverse cancer drug resistance.

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.

Novel insights into immune cells modulation of tumor resistance

Tumor resistance poses a significant challenge to effective cancer treatment, making it imperative to explore new therapeutic strategies. Recent studies have highlighted the profound involvement of immune cells in the development of tumor resistance. Within the tumor microenvironment, macrophages undergo polarization into the M2 phenotype, thus promoting the emergence of drug-resistant tumors. Neutrophils contribute to tumor resistance by forming extracellular traps. While T cells and natural killer (NK) cells exert their impact through direct cytotoxicity against tumor cells. Additionally, dendritic cells (DCs) have been implicated in preventing tumor drug resistance by stimulating T cell activation. In this review, we provide a comprehensive summary of the current knowledge regarding immune cell-mediated modulation of tumor resistance at the molecular level, with a particular focus on macrophages, neutrophils, DCs, T cells, and NK cells. The targeting of immune cell modulation exhibits considerable potential for addressing drug resistance, and an in-depth understanding of the molecular interactions between immune cells and tumor cells holds promise for the development of innovative therapies. Furthermore, we explore the clinical implications of these immune cells in the treatment of drug-resistant tumors. This review emphasizes the exploration of novel approaches that harness the functional capabilities of immune cells to effectively overcome drug-resistant tumors.

CYP24A1 affected macrophage polarization through degradation of vitamin D as a candidate biomarker for ovarian cancer prognosis

Ovarian cancer (OC) is a fatal gynecological malignancy with a poor prognosis in which mitochondria-related genes are involved deeply. In this study, we aim to screen mitochondria-related genes that play a role in OC prognosis and investigate its effects. Through single-cell sequencing technology and bioinformatics analysis, including TCGA ovarian cancer data analysis, gene expression signature analysis (GES), immune infiltration analysis, Gene Ontology (GO) enrichment analysis, Gene Set Enrichment Analysis (GSEA), and Principal Component Analysis (PCA), our findings revealed that CYP24A1 regulated macrophage polarization through vitamin D (VD) degradation and served as a target gene for the second malignant subtype of OC through bioinformatics analyses. For further validation, the expression and function of CYP24A1 in OC cells was investigated. And the expression of CYP24A1 was much higher in carcinoma than in paracancerous tissue, whereas the VD content decreased in the OC cell lines with CYP24A1 overexpression. Moreover, macrophages were polarized towards M1 after the intervention of VD-treated OC cell lines and inhibited the malignant phenotypes of OC. However, the effect could be reversed by overexpressing CYP24A1, resulting in the polarization of M2 macrophages, thereby promoting tumor progression, as verified by constructing xenograft models in vitro. In conclusion, our findings suggested that CYP24A1 induced M2 macrophage polarization through interaction with VD, thus promoting the malignant progression of OC.

Exosomes: Key Factors in Ovarian Cancer Peritoneal Metastasis and Drug Resistance

Ovarian cancer remains a leading cause of death among gynecological cancers, largely due to its propensity for peritoneal metastasis and the development of drug resistance. This review concentrates on the molecular underpinnings of these two critical challenges. We delve into the role of exosomes, the nano-sized vesicles integral to cellular communication, in orchestrating the complex interactions within the tumor microenvironment that facilitate metastatic spread and thwart therapeutic efforts. Specifically, we explore how exosomes drive peritoneal metastasis by promoting epithelial-mesenchymal transition in peritoneal mesothelial cells, altering the extracellular matrix, and supporting angiogenesis, which collectively enable the dissemination of cancer cells across the peritoneal cavity. Furthermore, we dissect the mechanisms by which exosomes contribute to the emergence of drug resistance, including the sequestration and expulsion of chemotherapeutic agents, the horizontal transfer of drug resistance genes, and the modulation of critical DNA repair and apoptotic pathways. By shedding light on these exosome-mediated processes, we underscore the potential of exosomal pathways as novel therapeutic targets, offering hope for more effective interventions against ovarian cancer's relentless progression.

Circ_103809 Aggravates the Malignant Phenotype of Pancreatic Cancer Through Modulating miR-197-3p/TSPAN3 Axis

Pancreatic cancer (PC) is a malignant tumor with insidious clinical manifestations and dismal prognosis. Emerging reports have demonstrated that circRNAs exert pivotal biological function in PC. Here, we investigated the crucial biological role and underlying regulatory mechanisms of differentially expressed circ_103809 in PC. In this study, hsa_circ_103809 (hsa_circ_0072088) was identified as the research object via analyzing and screening the aberrantly expressed circRNAs in PC by GSE69362 dataset. The levels of circ_103809 in PC tissues and cells were assessed via qRT-PCR. Functional assays were conducted to monitor the impacts of circ_103809 on PC cells. Additionally, the downstream molecular targets and regulatory networks of circ_103809 were predicted by bioinformatics and validated using luciferase assays and rescue experiments. We found that circ_103809 was substantially upregulated in PC tissues and cells. Silencing circ_103809 restrained the growth viability, clonogenic rate, migration, and invasion capabilities of PC cells. Further mechanistic exploration disclosed that miR-197-3p was the downstream gene of circ_103809, while Tetraspanin-3 (TSPAN3) was a direct target of miR-197-3p. The suppressive effect of circ_103809 knockdown on malignant processes of PC cells was eliminated by miR-197-3p downregulation or TSPAN3 upregulation. Our study demonstrated that circ_103809 served as an innovative positive regulator in the growth and metastasis of PC cells. Furthermore, circ_103809 mediated the miR-197-3p/TSPAN3 axis to modulate the malignant progression of PC cells, which was prospected to be a probable biomarker and an efficient therapeutic target for PC.

Drug resistance in human cancers - Mechanisms and implications

Cancers have complex etiology and pose a significant impact from the health care perspective apart from the socio-economic implications. The enormity of challenge posed by cancers can be understood from the fact that clinical trials for cancer therapy has yielded minimum potential promises compared to those obtained for other diseases. Surgery, chemotherapy and radiotherapy continue to be the mainstay therapeutic options for cancers. Among the challenges posed by these options, induced resistance to chemotherapeutic drugs is probably the most significant contributor for poor prognosis and ineffectiveness of the therapy. Drug resistance is a property exhibited by almost all cancer types including carcinomas, leukemias, myelomas, sarcomas and lymphomas. The mechanisms by which drug resistance is induced include the factors within the tumor microenvironment, mutations in the genes responsible for drug metabolism, changes in the surface drug receptors and increased drug efflux. We present here comprehensively the drug resistance in cancers along with their mechanisms. Also, apart from resistance to regularly used chemotherapeutic drugs, we present resistance induction to new generation therapeutic agents such as monoclonal antibodies. Finally, we have discussed the experimental approaches to understand the mechanisms underlying induction of drug resistance and potential ways to mitigate induced drug resistance.

Emerging Roles of Circular RNA in Macrophage Activation and Inflammatory Lung Responses

Circular RNA (circRNA) is a type of single-stranded RNA that forms a covalently closed continuous loop, unlike linear RNA. The expression of circRNAs in mammals is often conserved across species and shows tissue and cell specificity. Some circRNA serve as gene regulators. However, the biological function of most circRNAs is unclear. CircRNA does not have 5' or 3' ends. The unique structure of circRNAs provides them with a much longer half-life and more resistance to RNase R than linear RNAs. Inflammatory lung responses occur in the pathogenesis and recovery of many lung diseases. Macrophages form the first line of host defense/innate immune responses and initiate/mediate lung inflammation. For example, in bacterial pneumonia, upon pro-inflammatory activation, they release early response cytokines/chemokines that recruit neutrophils, macrophages, and lymphocytes to sites of infection and clear pathogens. The functional effects and mechanisms by which circRNAs exert physiological or pathological roles in macrophage activation and lung inflammation remain poorly understood. In this article, we will review the current understanding and progress of circRNA biogenesis, regulation, secretion, and degradation. Furthermore, we will review the current reports on the role of circRNAs in macrophage activation and polarization, as well as in the process of inflammatory lung responses.

circADAMTS6 via stabilizing CAMK2A is involved in smoking-induced emphysema through driving M2 macrophage polarization

Cigarette smoke (CS), an indoor environmental pollutant, is a prominent risk factor for emphysema, which is a pathological feature of chronic obstructive pulmonary disease (COPD). Emerging function of circRNAs in immune responses and disease progression shed new light to explore the pathogenesis of emphysema. In this research, we demonstrated, by single-cell RNA sequencing (scRNAseq), that the ratio of M2 macrophages were increased in lung tissues of humans and mice with smoking-related emphysema. Further, our data showed that circADAMTS6 was associated with cigarette smoke extract (CSE)-induced M2 macrophage polarization. Mechanistically, in macrophages, circADAMTS6 stabilized CAMK2A mRNA via forming a circADAMTS6/IGF2BP2/CAMK2A RNA-protein ternary complex to activate CREB, which drives M2 macrophage polarization and leads to emphysema. In addition, in macrophages of mouse lung tissues, downregulation of circADAMTS6 reversed M2 macrophage polarization, the proteinase/anti-proteinase imbalance, and the elastin degradation, which protecting against CS-induced emphysema. Moreover, for macrophages and in a model with co-cultured lung organoids, the target of circADAMTS6 restored the growth of lung organoids compared to CSE-treated macrophages. Our results also demonstrated that, for smokers and COPD smokers, elevation of circADAMTS6 negatively correlated with lung function. Overall, this study reveals a novel mechanism for circADAMTS6-driven M2 macrophage polarization in smoking-related emphysema and postulates that circADAMTS6 could serve as a diagnostic and therapeutic marker for smoking-related emphysema.

Identification and Comprehensive Analysis of circRNA-miRNA-mRNA Regulatory Networks in A2780 Cells Treated with Resveratrol

Ovarian cancer (OC) is one of the most commonplace gynecological malignancies. This study explored the effects of resveratrol (RES) on OC cell proliferation and apoptosis. Proliferation activity was measured for A2780 cells treated with RES for 24 h and 48 h at concentrations of 0, 10, 25, 50, 75, 100, 150, 200, and 300 μM. RNA sequencing (RNA-seq) was performed to analyze the circular RNA (circRNA), microRNA (miRNA), and messenger RNA (mRNA) expression spectrum. The differentially expressed genes included 460 circRNAs, 1988 miRNAs, and 1671 mRNAs, and they were subjected to analyses including Gene Ontology, the Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome enrichment. We selected signaling pathways enriched in the cell processes by mRNA KEGG, comprehensively analyzed the circRNA-miRNA-mRNA regulatory network, and verified several miRNAs expressed in the regulatory network diagram using the quantitative real-time polymerase chain reaction. The data showed that the cell proliferation of A2780 cells treated with RES for 24 h or 48 h decreased with increasing concentrations of RES. The circRNA-miRNA-mRNA regulatory network that we constructed provides new insights into the ability of RES to inhibit cell proliferation and promote apoptosis in A2780 cells.

Recent Advances in Nanoimmunotherapy by Modulating Tumor-Associated Macrophages for Cancer Therapy

Cancer immunotherapy has yielded remarkable results across a variety of tumor types. Nevertheless, the complex and immunosuppressive microenvironment within solid tumors poses significant challenges to established therapies such as immune checkpoint blockade (ICB) and chimeric antigen receptor T-cell (CAR-T) therapy. Within the milieu, tumor-associated macrophages (TAMs) play a significant role by directly suppressing T-cell functionality and fostering an immunosuppressive environment. Effective regulation of TAMs is, therefore, crucial to enhancing the efficacy of immunotherapies. Various therapeutic strategies targeting TAM modulation have emerged, including blocking TAM recruitment, direct elimination, promoting repolarization toward the M1 phenotype, and enhancing phagocytic capacity against tumor cells. The recently introduced CAR macrophage (CAR-M) therapy opens new possibilities for macrophage-based immunotherapy. Compared with CAR-T, CAR-M may demonstrate superior targeting and infiltration capabilities toward solid tumors. This review predominantly delves into the origin and development process of TAMs, their role in promoting tumor growth, and provides a comprehensive overview of immunotherapies targeting TAMs. It underscores the significance of regulating TAMs in bolstering antitumor therapies while discussing the potential and challenges of developing TAMs as targets for immunotherapy.

m6A reader IGF2BP2 promotes M2 macrophage polarization and malignant biological behavior of bladder cancer by stabilizing NRP1 mRNA expression

BACKGROUND

Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) has been confirmed to play oncogenic role in many cancers. However, the role and mechanism of IGF2BP2 in bladder cancer (BCa) still deserves to be further revealed.

METHODS

The mRNA and protein levels of IGF2BP2 and neuronilin-1 (NRP1) were detected by real-time quantitative PCR (RT-qPCR) and western blot. Cell proliferation, apoptosis, migration and invasion were determined using colony formation assay, EdU assay, CCK8 assay, flow cytometry and transwell assay. Xenograft tumor model was conducted to evaluate the role of IGF2BP2 in vivo. THP-1-M0 macrophages were co-cultured with the condition medium (CM) of BCa cells to induce polarization. M2 macrophage polarization was assessed by detecting the mRNA levels of M2 macrophage markers using RT-qPCR and measuring the proportion of M2 macrophage markers using flow cytometry. Moreover, MeRIP and RIP assay were performed to assess m6A level and the interaction between IGF2BP2 and NRP1.

RESULTS

IGF2BP2 and NRP1 were upregulated in BCa tissues and cells. IGF2BP2 knockdown suppressed BCa cell growth and metastasis, as well as inhibited BCa tumor growth. After THP-1-M0 macrophages were co-cultured with the CM of BCa cells, the levels of M2 macrophage markers were markedly enhanced, while this effect was abolished by IGF2BP2 knockdown. IGF2BP2 level was positively correlated with NRP1 level, and it could increase NRP1 mRNA stability. NRP1 overexpression reversed the suppressive effect of IGF2BP2 knockdown on M2 macrophage polarization and BCa cell progression.

CONCLUSION

m6A-reader IGF2BP2 enhanced M2 macrophage polarization and BCa cell progression by promoting NRP1 mRNA stability.

Single-cell RNA sequencing in ovarian cancer: revealing new perspectives in the tumor microenvironment

Single-cell sequencing technology has emerged as a pivotal tool for unraveling the complexities of the ovarian tumor microenvironment (TME), which is characterized by its cellular heterogeneity and intricate cell-to-cell interactions. Ovarian cancer (OC), known for its high lethality among gynecologic malignancies, presents significant challenges in treatment and diagnosis, partly due to the complexity of its TME. The application of single-cell sequencing in ovarian cancer research has enabled the detailed characterization of gene expression profiles at the single-cell level, shedding light on the diverse cell populations within the TME, including cancer cells, stromal cells, and immune cells. This high-resolution mapping has been instrumental in understanding the roles of these cells in tumor progression, invasion, metastasis, and drug resistance. By providing insight into the signaling pathways and cell-to-cell communication mechanisms, single-cell sequencing facilitates the identification of novel therapeutic targets and the development of personalized medicine approaches. This review summarizes the advancement and application of single-cell sequencing in studying the stromal components and the broader TME in OC, highlighting its implications for improving diagnosis, treatment strategies, and understanding of the disease's underlying biology.