HIF-1α downregulation of miR-433-3p in adipocyte-derived exosomes contributes to NPC progression via targeting SCD1

Regulation of Cancer-Associated miRNAs Expression under Hypoxic Conditions

Solid tumors frequently experience hypoxia or low O2 levels. In these conditions, hypoxia-inducible factor 1 alpha (HIF-1α) is activated and acts as a transcription factor that regulates cancer cell adaptation to O2 and nutrient deprivation. HIF-1α controls gene expression associated with various signaling pathways that promote cancer cell proliferation and survival. MicroRNAs (miRNAs) are 22-nucleotide noncoding RNAs that play a role in various biological processes essential for cancer progression. This review presents an overview of how hypoxia regulates the expression of multiple miRNAs in the progression of cancer cells.

Obese Mouse Fat Cell-derived Extracellular Vesicles Transport miR-99a-5p to Mitigate the Proliferation and Migration of Non-small Cell Lung Cancer Cells

OBJECTIVE

Fat cells-derived extracellular vesicles (FC-EVs) play a role in regulating the tumor microenvironment in cancers by transporting RNAs. MicroRNAs (miRNAs) are vital regulators of cancer development. This study was conducted to explore the role of FC-EVs in the proliferation and migration of non-small cell lung cancer (NSCLC) cells, providing targets for NSCLC treatment.

METHODS

The obese mouse model was established via high-fat diet (HFD), followed by separation and characterization of FC-EVs (HFD-EVs). The levels of miR-99a-5p, precursor-miR-99a-5p, and heparan sulfate-glucosamine 3-sulfotransferase 3B1 (HS3ST3B1) were measured by RT-qPCR or Western blot assay. Cell proliferation and migration were evaluated by 3-(4, 5-dimethylthiazol- 2-yl)-2, 5-diphenyltetrazolium bromide and wound healing assays. The expression of Cy3-labeled miR-99a-5p in A549 cells (one NSCLC cell line) was observed via confocal microscopy. The binding of miR-99a-5p to HS3ST3B1 was analyzed by the dual luciferase assay. Rescue experiments were performed to confirm the role of HS3ST3B1 in NSCLC cells.

RESULTS

miR-99a-5p was upregulated in adipose tissues, FCs, and HFD-EVs. HFD-EVs mitigated the proliferation and migration of NSCLC cells. HFD-EVs transported miR-99a-5p into A549 cells, which upregulated miR-99a-5p expression and inhibited HS3ST3B1 expression in A549 cells. HS3ST3B1 overexpression reversed the inhibition of HFD-EVs on the proliferation and migration of NSCLC cells.

CONCLUSION

HFD-EVs transported miR-99a-5p into NSCLC cells and inhibited HS3ST3B1, thereby inhibiting proliferation and migration of NSCLC cells.

Circadian clock and lipid metabolism disorders: a potential therapeutic strategy for cancer

Recent research has emphasized the interaction between the circadian clock and lipid metabolism, particularly in relation to tumors. This review aims to explore how the circadian clock regulates lipid metabolism and its impact on carcinogenesis. Specifically, targeting key enzymes involved in fatty acid synthesis (SREBP, ACLY, ACC, FASN, and SCD) has been identified as a potential strategy for cancer therapy. By disrupting these enzymes, it may be possible to inhibit tumor growth by interfering with lipid metabolism. Transcription factors, like SREBP play a significant role in regulating fatty acid synthesis which is influenced by circadian clock genes such as BMAL1, REV-ERB and DEC. This suggests a strong connection between fatty acid synthesis and the circadian clock. Therefore, successful combination therapy should target fatty acid synthesis in addition to considering the timing and duration of drug use. Ultimately, personalized chronotherapy can enhance drug efficacy in cancer treatment and achieve treatment goals.

Recent advances in exosome-based immunotherapy applied to cancer

Cancer stands as a prominent contributor to global mortality rates, necessitating immediate attention toward the exploration of its treatment options. Extracellular vesicles have been investigated as a potential cancer therapy in recent years. Among them, exosomes, as cell-derived nanovesicles with functions such as immunogenicity and molecular transfer, offer new possibilities for immunotherapy of cancer. However, multiple studies have shown that exosomes of different cellular origins have different therapeutic effects. The immunomodulatory effects of exosomes include but are not limited to inhibiting or promoting the onset of immune responses, regulating the function of molecular signaling pathways, and serving as carriers of antitumor drugs. Therefore, this mini-review attempts to summarize and evaluate the development of strategies for using exosomes to package exogenous cargos to promote immunotherapy in cancer.

Exosomal noncoding RNA-mediated spatiotemporal regulation of lipid metabolism: Implications in immune evasion and chronic inflammation

The hallmark of chronic inflammatory diseases is immune evasion. Successful immune evasion involves numerous mechanisms to suppress both adaptive and innate immune responses. Either direct contact between cells or paracrine signaling triggers these responses. Exosomes are critical drivers of these interactions and exhibit both immunogenic and immune evasion properties during the development and progression of various chronic inflammatory diseases. Exosomes carry diverse molecular cargo, including lipids, proteins, and RNAs that are crucial for immunomodulation. Moreover, recent studies have revealed that exosomes and their cargo-loaded molecules are extensively involved in lipid remodeling and metabolism during immune surveillance and disease. Many studies have also shown the involvement of lipids in controlling immune cell activities and their crucial upstream functions in regulating inflammasome activation, suggesting that any perturbation in lipid metabolism results in abnormal immune responses. Strikingly, the expanded immunometabolic reprogramming capacities of exosomes and their contents provided insights into the novel mechanisms behind the prophylaxis of inflammatory diseases. By summarizing the tremendous therapeutic potential of exosomes, this review emphasizes the role of exosome-derived noncoding RNAs in regulating immune responses through the modulation of lipid metabolism and their promising therapeutic applications.

MicroRNA-199a-3p suppresses the invasion and metastasis of nasopharyngeal carcinoma through SCD1/PTEN/AKT signaling pathway

MicroRNAs (miRs) are 18-25 nucleotides non-coding RNAs, which contribute to tumorigenesis. Previous studies have demonstrated that miR-199a-3p is dysregulated in human nasopharyngeal carcinoma (NPC), but its role in NPC progression still largely unknown. The current study aimed to determine the potential role of miR-199a-3p in NPC progression and the underlying mechanisms. In this study, miR-199a-3p was found to be prominently down-regulated in NPC tissues and cells. The cellular assay showed that transfection of miR-199a-3p markedly repressed the migration, invasion and induced epithelial-mesenchymal transition (EMT) in both 5-8F and CNE-2 cell lines. By dual-luciferase reporter, western blotting and gas chromatography assays, we found that SCD1 is not only highly expressed in NPC tissues and negatively associated with the prognosis of NPC patients but also can be apparently downregulated by miR-199a-3p in NPC cells, suggesting that SCD1 is a direct target gene of miR-199a-3p. Moreover, inhibition of miR-199a-3p expression activated PI3K/Akt signaling and up-regulated the expression of MMP-2. With tumor xenograft models in nude mice, we also showed that miR-199a-3p repressed tumor growth in vivo. Our study demonstrated that miR-199a-3p inhibited migration and invasion of NPC cells through downregulating SCD1 expression, thus providing a potential target for the treatment of NPC.

Adipocyte-derived extracellular vesicles: bridging the communications between obesity and tumor microenvironment

By the year 2035 more than 4 billion people might be affected by obesity and being overweight. Adipocyte-derived Extracellular Vesicles (ADEVs/ADEV-singular) are essential for communication between the tumor microenvironment (TME) and obesity, emerging as a prominent mechanism of tumor progression. Adipose tissue (AT) becomes hypertrophic and hyperplastic in an obese state resulting in insulin resistance in the body. This modifies the energy supply to tumor cells and simultaneously stimulates the production of pro-inflammatory adipokines. In addition, obese AT has a dysregulated cargo content of discharged ADEVs, leading to elevated amounts of pro-inflammatory proteins, fatty acids, and carcinogenic microRNAs. ADEVs are strongly associated with hallmarks of cancer (proliferation and resistance to cell death, angiogenesis, invasion, metastasis, immunological response) and may be useful as biomarkers and antitumor therapy strategy. Given the present developments in obesity and cancer-related research, we conclude by outlining significant challenges and significant advances that must be addressed expeditiously to promote ADEVs research and clinical applications.

Can the apparent transverse relaxation rate (R2*) evaluate the efficacy of concurrent chemoradiotherapy in locally advanced nasopharyngeal carcinoma? a preliminary experience

BACKGROUND

The use of the apparent transverse relaxation rate (R2^*) in nasopharyngeal carcinoma (NPC) has not been previously reported in the literature. The aim of this study was to investigate the role of the R2^* value in evaluating response to concurrent chemoradiotherapy (CCRT) in patients with NPC.

METHODS

Forty-one patients with locoregionally advanced NPC confirmed by pathology were examined by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) before and after CCRT, and conventional MRI was performed 3 months after the completion of CCRT. All patients were divided into a responding group (RG) and a nonresponding group (NRG), according to MRI findings 3 months after the end of treatment. The R2^* values before (R2*_preT) and after (R2^*_postT) CCRT and the ΔR2^* (ΔR2^*=R2^*_postT - R2^*_preT) were calculated in the tumor.

RESULTS

Among the 41 patients, 26 were in the RG and 15 were in the NRG. There was no statistical difference in the R2^*_preT between RG and NRG (P = 0.307); however, there were significant differences in R2^*_postT and ΔR2^* (P < 0.001). The area under the curve of R2^*_postT and ΔR2^* for predicting the therapeutic response of NPC was 0.897 and 0.954, respectively, with cutoff values of 40.95 and 5.50 Hz, respectively.

CONCLUSION

The R2^* value can be used as a potential imaging indicator to evaluate the therapeutic response of locoregionally advanced NPC.

Extracellular Vesicles as Biomarkers in Head and Neck Squamous Cell Carcinoma: From Diagnosis to Disease-Free Survival

Head and neck squamous cell carcinomas (HNSCCs) arising from different anatomical sites present with different incidences and characteristics, which requires a personalized treatment strategy. Despite the extensive research that has conducted on this malignancy, HNSCC still has a poor overall survival rate. Many attempts have been made to improve the outcomes, but one of the bottlenecks is thought to be the lack of an effective biomarker with high sensitivity and specificity. Extracellular vesicles (EVs) are secreted by various cells and participate in a great number of intercellular communications. Based on liquid biopsy, EV detection in several biofluids, such as blood, saliva, and urine, has been applied to identify the existence and progression of a variety of cancers. In HNSCC, tumor-derived EVs exhibit many functionalities by transporting diverse cargoes, which highlights their importance in tumor screening, the determination of multidisciplinary therapy, prediction of prognosis, and evaluation of therapeutic effects. This review illustrates the classification and formation of EV subtypes, the cargoes conveyed by these vesicles, and their respective functions in HNSCC cancer biology, and discloses their potential as biomarkers during the whole process of tumor diagnosis, treatment, and follow-up.

Exosomal cargos-mediated metabolic reprogramming in tumor microenvironment

Metabolic reprogramming is one of the hallmarks of cancer. As nutrients are scarce in the tumor microenvironment (TME), tumor cells adopt multiple metabolic adaptations to meet their growth requirements. Metabolic reprogramming is not only present in tumor cells, but exosomal cargos mediates intercellular communication between tumor cells and non-tumor cells in the TME, inducing metabolic remodeling to create an outpost of microvascular enrichment and immune escape. Here, we highlight the composition and characteristics of TME, meanwhile summarize the components of exosomal cargos and their corresponding sorting mode. Functionally, these exosomal cargos-mediated metabolic reprogramming improves the "soil" for tumor growth and metastasis. Moreover, we discuss the abnormal tumor metabolism targeted by exosomal cargos and its potential antitumor therapy. In conclusion, this review updates the current role of exosomal cargos in TME metabolic reprogramming and enriches the future application scenarios of exosomes.

Application of small extracellular vesicles in the diagnosis and prognosis of nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant tumor originating from the epithelium of the nasopharynx. The disease is insidious, and most patients are diagnosed at the advanced stage, resulting in poor prognosis. Early diagnosis is important to reduce NPC mortality. Small extracellular vesicles (sEVs) are rich in a variety of bioactive molecules, such as proteins, nucleic acids, and lipids, which can participate in the physiological and pathological regulation of the body by affecting the function of target cells. Numerous studies have shown that some RNAs and proteins in sEVs of tumor origin have a key role in the development of NPC and are potential candidates for malignancy detection. Studying the relationship between the cargoes of these sEVs and NPC may help in the diagnosis of the disease. Here in this review, we summarize the application of sEVs as biomarkers in the diagnosis of NPC and their role in NPC metastasis and prognosis. In addition, we discuss possible future applications and limitations of sEVs as biomarkers.

EBV promotes vascular mimicry of dormant cancer cells by potentiating stemness and EMT

Vascular mimicry (VM) is defined as a vascular channel-like structure composed of tumor cells that correlates with the growth of cancer cells by providing blood circulation. However, whether VM can be formed in dormant cancer cells remains unclear. Our previous research revealed that polyploid giant cancer cells (PGCCs) are specific dormant cells related to the poor prognosis of head and neck cancer. Here, we demonstrated that EBV could promote VM formation by PGCCs in vivo and in vitro. Furthermore, we revealed that the activation of the ERK pathway partly mediated by LMP2A is responsible for stemness, and the acquisition of the stemness phenotype is crucial to the malignant biological behavior of PGCCs. The epithelial-to-mesenchymal transition (EMT) process plays a considerable role in PGCCs, and EMT progression is vital for EBV-positive PGCCs to form VM. This is the first study to reveal that EBV creates plasticity in PGCC-VM and provide a new strategy for targeted anti-tumor therapy.

The role of MiRNA ‐433 in malignant tumors of digestive tract as tumor suppressor

Background

MicroRNAs (miRNAs) are a class of short non‐coding RNAs with a length of approximate 22 nuclei acids that can be expressed both as an oncogene and tumor suppressor gene in human cancers. MiRNAs can participate in the post‐ transcriptional regulation of gene expression, and regulate the several cancer‐related processes, including proliferation, apoptosis, metastasis, etc.

Recent findings

Expression of miRNA‐433 has been reported to vary in different tumors and affected by various factors. We have summarized the different previous studies and found that miRNA‐433 can significantly inhibit the growth of the cancer cells not only in malignant tumors of the digestive tract, but also in lung cancer, breast cancer, cervical cancer, ovarian cancer, bladder cancer, renal carcinoma, glioma, retinoblastoma and osteosarcoma.

Conclusion

When the expression of miRNA‐433 was up‐regulated, the proliferation, metastasis and invasion abilities of the malignant tumor cells were significantly inhibited. At the same time, the potential mechanisms through which miRNA‐433 can suppress the growth and metastasis of the cancer cells were found to be basically the same, and involved modulation of the specific signaling pathways or target genes in the malignant tumors. Overall, it can be concluded that miRNA‐433 can serve as potential and valuable therapeutic target.

Emerging role of exosomes in cancer progression and tumor microenvironment remodeling

Cancer is one of the leading causes of death worldwide, and the factors responsible for its progression need to be elucidated. Exosomes are structures with an average size of 100 nm that can transport proteins, lipids, and nucleic acids. This review focuses on the role of exosomes in cancer progression and therapy. We discuss how exosomes are able to modulate components of the tumor microenvironment and influence proliferation and migration rates of cancer cells. We also highlight that, depending on their cargo, exosomes can suppress or promote tumor cell progression and can enhance or reduce cancer cell response to radio- and chemo-therapies. In addition, we describe how exosomes can trigger chronic inflammation and lead to immune evasion and tumor progression by focusing on their ability to transfer non-coding RNAs between cells and modulate other molecular signaling pathways such as PTEN and PI3K/Akt in cancer. Subsequently, we discuss the use of exosomes as carriers of anti-tumor agents and genetic tools to control cancer progression. We then discuss the role of tumor-derived exosomes in carcinogenesis. Finally, we devote a section to the study of exosomes as diagnostic and prognostic tools in clinical courses that is important for the treatment of cancer patients. This review provides a comprehensive understanding of the role of exosomes in cancer therapy, focusing on their therapeutic value in cancer progression and remodeling of the tumor microenvironment.

Prospective Application of Ferroptosis in Hypoxic Cells for Tumor Radiotherapy

Radiation therapy plays an increasingly important role in cancer treatment. It can inhibit the progression of various cancers through radiation-induced DNA breakage and reactive oxygen species (ROS) overload. Unfortunately, solid tumors, such as breast and lung cancer, often develop a hypoxic microenvironment due to insufficient blood supply and rapid tumor proliferation, thereby affecting the effectiveness of radiation therapy. Restraining hypoxia and improving the curative effect of radiotherapy have become difficult problems. Ferroptosis is a new type of cell death caused by lipid peroxidation due to iron metabolism disorders and ROS accumulation. It plays an important role in both hypoxia and radiotherapy and can enhance the radiosensitivity of hypoxic tumor cells by amplifying oxidative stress or inhibiting antioxidant regulation. In this review, we summarize the internal relationship and related mechanisms between ferroptosis and hypoxia, thus exploring the possibility of inducing ferroptosis to improve the prognosis of hypoxic tumors.

Hypoxia Induced Changes of Exosome Cargo and Subsequent Biological Effects

Exosomes are small extracellular vesicles that are secreted by almost all types of cells and exist in almost all extracellular spaces. As an important mediator of intercellular communication, exosomes encapsulate the miRNA, lncRNA, cirRNA, mRNA, cytokine, enzyme, lipid, and other components from the cytoplasm into its closed single membrane structure and transfer them to recipient units in an autocrine, paracrine, or endocrine manner. Hypoxia is a state of low oxygen tension and is involved in many pathological processes. Hypoxia influences the size, quantity, and expression of exosome cargos. Exosomes derived from hypoxic tumor cells transfer genetics, proteins, and lipids to the recipient units to exert pleiotropic effects. Different donor cells produce different cargo contents, target different recipient units and lead to different biological effects. Hypoxic exosomes derived from tumor cells uptaken by normoxic tumor cells lead to promoted proliferation, migration, and invasion; uptaken by extracellular space or liver lead to promoted metastasis; uptaken by endothelial cells lead to promoted angiogenesis; uptaken by immune cells lead to promoted macrophage polarization and changed tumor immune microenvironment. In addition to various types of tumors, hypoxic exosomes also participate in the development of diseases in the cardiovascular system, neuron system, respiratory system, hematology system, endocrine system, urinary system, reproduction system, and skeletomuscular system. Understanding the special characteristics of hypoxic exosomes provide new insight into elaborating the pathogenesis of hypoxia related disease. This review summarizes hypoxia induced cargo changes and the biological effects of hypoxic exosomes in tumors and non-malignant diseases in different systems.

Nasopharyngeal Carcinoma and Its Microenvironment: Past, Current, and Future Perspectives

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy that raises public health concerns in endemic countries. Despite breakthroughs in therapeutic strategies, late diagnosis and drug resistance often lead to unsatisfactory clinical outcomes in NPC patients. The tumor microenvironment (TME) is a complex niche consisting of tumor-associated cells, such as fibroblasts, endothelial cells, leukocytes, that influences tumor initiation, progression, invasion, and metastasis. Cells in the TME communicate through various mechanisms, of note, exosomes, ligand-receptor interactions, cytokines and chemokines are active players in the construction of TME, characterized by an abundance of immune infiltrates with suppressed immune activities. The NPC microenvironment serves as a target-rich niche for the discovery of potential promising predictive or diagnostic biomarkers and the development of therapeutic strategies. Thus, huge efforts have been made to exploit the role of the NPC microenvironment. The whole picture of the NPC microenvironment remains to be portrayed to understand the mechanisms underlying tumor biology and implement research into clinical practice. The current review discusses the recent insights into the role of TME in the development and progression of NPC which results in different clinical outcomes of patients. Clinical interventions with the use of TME components as potential biomarkers or therapeutic targets, their challenges, and future perspectives will be introduced. This review anticipates to provide insights to the researchers for future preclinical, translational and clinical research on the NPC microenvironment.

Exosomes in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a malignant epithelial tumor with a unique geographical distribution, primarily prevalent in East Africa and Asia. Although there is an increased understanding of the pathogenesis and risk factors of NPC, prevention and treatment efforts remain limited. Various studies have indicated that exosomes are actively involved in NPC by delivering biomolecules such as non-coding RNAs and proteins to target cells. In this review, we summarize the biological functions of exosomes in NPC and highlight their prospects as diagnostic biomarkers. In NPC, exosomes can manipulate the tumor microenvironment, participate in chemotherapy and radiation resistance, induce immune suppression, promote pathological angiogenesis, and support metastasis, and thus they could also be promising biomarkers. Because exosomes have essential effects and unusual biological properties, they have a promising future in diagnostic monitoring and prognostic evaluation. Although there are technical issues associated with using exosomes in large-scale applications, they have unparalleled advantages in assisting the clinical management of NPC.

HIF-1α downregulation of miR-433-3p in adipocyte-derived exosomes contributes to NPC progression via targeting SCD1

Resident adipocytes under a hypoxic tumor microenvironment exert an increasingly important role in cell growth, proliferation, and invasion in cancers. However, the communication between adipocytes and cancer cells during nasopharyngeal carcinoma (NPC) progression is poorly understood. Here, we demonstrate that hypoxic adipocyte‐derived exosomes are key information carriers that transfer low expression of miR‐433‐3p into NPC cells. In addition, luciferase reporter assays detected that hypoxia inducible factor‐1α (HIF‐1α) induced miR‐433‐3p transcription through five binding sites at its promoter region. Concordantly, the low expression of miR‐433‐3p promoted proliferation, migration, and lipid accumulation in NPC cells via targeting stearoyl‐CoA desaturase 1 (SCD1) are suggested by functional studies. Consistent with these findings, in tumor‐bearing mice, NPC cells with low HIF‐1α expression, high miR‐433‐3p expression, and low SCD1 expression were equally endowed with remarkably reduced potential of tumorigenesis. Collectively, our study highlights the critical role of the HIF‐1α‐miR‐433‐3p‐SCD1 axis in NPC progression, which can serve as a mechanism‐based potential therapeutic approach.