Tumor necrosis factor receptor 2 promotes endothelial cell-mediated suppression of CD8+ T cells through tuning glycolysis in chemoresistance of breast cancer.

BACKGROUND: T cells play a pivotal role in chemotherapy-triggered anti-tumor effects. Emerging evidence underscores the link between impaired anti-tumor immune responses and resistance to paclitaxel therapy in triple-negative breast cancer (TNBC). Tumor-related endothelial cells (ECs) have potential immunoregulatory activity. However, how ECs regulate T cell activity during TNBC chemotherapy remains poorly understood. METHODS: Single-cell analysis of ECs in patients with TNBC receiving paclitaxel therapy was performed using an accessible single-cell RNA sequencing (scRNA-seq) dataset to identify key EC subtypes and their immune characteristics. An integrated analysis of a tumor-bearing mouse model, immunofluorescence, and a spatial transcriptome dataset revealed the spatial relationship between ECs, especially Tumor necrosis factor receptor (TNFR) 2+ ECs, and CD8+ T cells. RNA sequencing, CD8+ T cell proliferation assays, flow cytometry, and bioinformatic analyses were performed to explore the immunosuppressive function of TNFR2 in ECs. The downstream metabolic mechanism of TNFR2 was further investigated using RNA sequencing, cellular glycolysis assays, and western blotting. RESULTS: In this study, we identified an immunoregulatory EC subtype, characterized by enhanced TNFR2 expression in non-responders. By a mouse model of TNBC, we revealed a dynamic reduction in the proportion of the CD8+ T cell-contacting tumor vessels that could co-localize spatially with CD8+ T cells during chemotherapy and an increased expression of TNFR2 by ECs. TNFR2 suppresses glycolytic activity in ECs by activating NF-κB signaling in vitro. Tuning endothelial glycolysis enhances programmed death-ligand (PD-L) 1-dependent inhibitory capacity, thereby inducing CD8+ T cell suppression. In addition, TNFR2+ ECs showed a greater spatial affinity for exhausted CD8+ T cells than for non-exhausted CD8+ T cells. TNFR2 blockade restores impaired anti-tumor immunity in vivo, leading to the loss of PD-L1 expression by ECs and enhancement of CD8+ T cell infiltration into the tumors. CONCLUSIONS: These findings reveal the suppression of CD8+ T cells by ECs in chemoresistance and indicate the critical role of TNFR2 in driving the immunosuppressive capacity of ECs via tuning glycolysis. Targeting endothelial TNFR2 may serve as a potent strategy for treating TNBC with paclitaxel.

Hyperexpression of tumor necrosis factor receptor 2 inhibits differentiation of myeloid-derived suppressor cells by instigating apolarity during ageing.

During the ageing process, TNF-α can promote the expansion of myeloid-derived suppressor cells (MDSCs). However, it remains unclear which receptor(s) of TNF-α are involved in and how they modulate this process. Here, we report that TNFR2 hyperexpression induced by either TNF-α or IL-6, two proinflammatory factors of senescence-associated secretory phenotype (SASP), causes cellular apolarity and differentiation inhibition in aged MDSCs. Ex vivo overexpression of TNFR2 in young MDSCs inhibited their polarity and differentiation, whereas in vivo depletion of Tnfr2 in aged MDSCs promotes their differentiation. Consequently, the age-dependent increase of TNFR2 versus unaltered TNFR1 expression in aged MDSCs significantly shifts the balance of TNF-α signaling toward the TNFR2-JNK axis, which accounts for JNK-induced impairment of cell polarity and differentiation failure of aged MDSCs. Consistently, inhibiting JNK attenuates apolarity and partially restores the differentiation capacity of aged MDSCs, suggesting that upregulated TNFR2/JNK signaling is a key factor limiting MDSC differentiation during organismal ageing. Therefore, abnormal hyperexpression of TNFR2 represents a general mechanism by which extrinsic SASP signals disrupt intrinsic cell polarity behavior, thereby arresting mature differentiation of MDSCs with ageing, suggesting that TNFR2 could be a potential therapeutic target for intervention of ageing through rejuvenation of aged MDSCs.

IFN-γ-responsiveness of lymphatic endothelial cells inhibits melanoma lymphatic dissemination via AMPK-mediated metabolic control.

The integrity of the lymphatic system is critical for preventing the dissemination of tumor cells, such as melanoma, to distant parts of the body. IFN-γ is well studied as a negative regulator for lymphangiogenesis, which is strongly associated with cancer metastasis. However, the exact mechanisms underlying this process remain unclear. In the present study, we investigated whether IFN-γ signaling in lymphatic endothelial cells (LECs) affects tumor cell dissemination by regulating the barrier function of tumor-associated lymphatic vessels. Using LEC-specific IFN-γ receptor (IFN-γR) knockout mice, we found that the loss of IFN-γR in LECs increased the dissemination of melanoma cells into the draining lymph nodes. Notably, IFN-γ signaling in LECs inhibited trans-lymphatic endothelial cell migration of melanoma cells, indicating its regulation of lymphatic barrier function. Further investigations revealed that IFN-γ upregulated the expression of the tight junction protein Claudin-3 in LECs, while knockdown of Claudin-3 in LECs abolished IFN-γ-induced inhibition of trans-lymphatic endothelial migration activity. Mechanistically, IFN-γ inhibits AMPK signaling activation, which is involved in the regulation of fatty acid metabolism. Modulating fatty acid metabolism and AMPK activation in LECs also affected the lymphatic dissemination of melanoma cells, further confirming that this process is involved in IFN-γ-induced regulation of lymphatic barrier function. These results provide novel insights into how IFN-γ modulates tight junctions in LECs, inhibiting the dissemination of melanoma cells via the lymphatic vessels.

Chemotherapy-induced PTEN-L secretion promotes the selection of PTEN-deficient tumor cells.

BACKGROUND: PTEN loss has been identified in various tumor types and is linked to unfavorable clinical outcomes. In addition to PTEN mutation, multiple mechanisms contribute to PTEN loss during tumor development. However, the natural selection process of PTEN-deficient tumor cells remains unclear. Here, we aimed at further elucidating the role of PTEN-L in tumor progression. METHODS: PTEN knockout cell lines were generated using CRISPR/Cas9 technology. Ni-NTA affinity column chromatography was employed for PTEN-L purification. Tumor cell metastasis was evaluated in murine models and observed using the IVIS Spectrum Imaging System. RNA-sequencing, western blotting, PCR, flow cytometry, and cell proliferation assays were employed to investigate tumor cell dormancy and related mechanisms. RESULTS: The chemotherapeutic drugs, cisplatin, paclitaxel, and doxorubicin, induced tumor cells to secrete PTEN-long (PTEN-L), which shields PTEN-deficient tumor cells from chemotherapy-induced apoptosis better than it shields PTEN-intact cells. Further investigation revealed that PTEN-L treatment induced dormancy in PTEN-null tumor cells, characterized by an increase in p16 and p27 levels, cell-cycle arrest, reduced cell proliferation, and enhanced DNA repair. Furthermore, PTEN-L treatment selectively promoted the accumulation and growth of PTEN-null tumor cells in the lungs of C57BL/6J mice, while evading immune surveillance. Mechanistically, PTEN-L induced dormancy in PTEN-null tumor cells by activating the p38 signaling pathway. Addition of a p38 inhibitor effectively reversed dormancy and growth of PTEN-deficient tumor cells in the lungs. We also demonstrated that PTEN expression played a pivotal role in determining the outcome of PTEN-L-mediated antitumor therapy. CONCLUSIONS: In summary, PTEN-L was identified as a potent inducer of dormancy in PTEN-deficient tumor cells, which increased their efficient selection within the tumor microenvironment.

The role of amino acid metabolism in autoimmune hepatitis.

Autoimmune hepatitis (AIH) is an inflammatory chronic liver disease with persistent and recurrent immune-mediated liver injury. The exact cause of AIH is still not fully understood, but it is believed to be primarily due to an abnormal activation of the immune system, leading to autoimmune injury caused by the breakdown of autoimmune tolerance. Although the pathogenesis of AIH remains unclear, recent studies have shown that abnormalities in amino acid metabolism play significant roles in its development. These abnormalities in amino acid metabolism can lead to remodeling of metabolic processes, activation of signaling pathways, and immune responses, which may present new opportunities for clinical intervention in AIH. In this paper, we first briefly outline the recent progress of clinically relevant research on AIH, focusing on the role of specific amino acid metabolism (including glutamine, cysteine, tryptophan, branched-chain amino acids, etc.) and their associated metabolites, as well as related pathways, in the development of AIH. Furthermore, we discuss the scientific issues that remain to be resolved regarding amino acid metabolism, AIH development and related clinical interventions, with the aim of contributing to the future development of amino acid metabolism-based as a new target for the clinical diagnosis and treatment of AIH.

Targeting lipid metabolism of macrophages: A new strategy for tumor therapy.

BACKGROUND: Lipid metabolism has been implicated in a variety of normal cellular processes and strongly related to the development of multiple diseases, including tumor. Tumor-associated macrophage (TAM) has emerged as a crucial regulator in tumorigenesis and promising target for tumor treatment. AIM OF REVIEW: A thorough understanding of TAM lipid metabolism and its value in tumorigenesis may provide new ideas for TAM-based anti-tumor therapy. Key scientific concepts of review: TAMs can be divided into two main types, M1-like TAMs and M2-like TAMs, which play anti-tumor and pro-tumor functions in tumor occurrence and development, respectively. Accumulating evidence has shown that lipid metabolic reprogramming, including fatty acid uptake and utilization, cholesterol expulsion, controls the polarization of TAMs and affects the tumorgenesis. These advances in uncovering the intricacies of lipid metabolism and TAMs have yielded new insights on tumor development and treatment. In this review, we aim to provide an update on the current understanding of the lipid metabolic reprogramming made by TAMs to adapt to the harsh tumor microenvironment (TME). In particular, we emphasize that there is complex lipid metabolism connections between TAMs and distinct tumors, which influences TAM to bias from M1 to M2 phenotype in tumor progression, and ultimately promotes tumor occurrence and development. Finally, we discuss the existing issues on therapeutic strategies by reprogramming TAMs based on lipid metabolism regulation (or increasing the ratio of M1/M2-like TAMs) that could be applied in the future to clinical tumor treatment.

Intestinal microbiota: A bridge between intermittent fasting and tumors.

Intestinal microbiota and their metabolites are essential for maintaining intestinal health, regulating inflammatory responses, and enhancing the body's immune function. An increasing number of studies have shown that the intestinal microbiota is tightly tied to tumorigenesis and intervention effects. Intermittent fasting (IF) is a method of cyclic dietary restriction that can improve energy metabolism, prolong lifespan, and reduce the progression of various diseases, including tumors. IF can affect the energy metabolism of tumor cells, inhibit tumor cell growth, improve the function of immune cells, and promote an anti-tumor immune response. Interestingly, recent research has further revealed that the intestinal microbiota can be impacted by IF, in particular by changes in microbial composition and metabolism. These findings suggest the complexity of the IF as a promising tumor intervention strategy, which merits further study to better understand and encourage the development of clinical tumor intervention strategies. In this review, we aimed to outline the characteristics of the intestinal microbiota and its mechanisms in different tumors. Of note, we summarized the impact of IF on intestinal microbiota and discussed its potential association with tumor suppressive effects. Finally, we proposed some key scientific issues that need to be addressed and envision relevant research prospects, which might provide a theoretical basis and be helpful for the application of IF and intestinal microbiota as new strategies for clinical interventions in the future.

A Comprehensive Review of Pea (Pisum sativum L.): Chemical Composition, Processing, Health Benefits, and Food Applications.

Pisum sativum L., commonly referred to as dry, green, or field pea, is one of the most common legumes that is popular and economically important. Due to its richness in a variety of nutritional and bioactive ingredients, the consumption of pea has been suggested to be associated with a wide range of health benefits, and there has been increasing focus on its potential as a functional food. However, there have been limited literature reviews concerning the bioactive compounds, health-promoting effects, and potential applications of pea up to now. This review, therefore, summarizes the literature from the last ten years regarding the chemical composition, physicochemical properties, processing, health benefits, and potential applications of pea. Whole peas are rich in macronutrients, including proteins, starches, dietary fiber, and non-starch polysaccharides. In addition, polyphenols, especially flavonoids and phenolic acids, are important bioactive ingredients that are mainly distributed in the pea coats. Anti-nutritional factors, such as phytic acid, lectin, and trypsin inhibitors, may hinder nutrient absorption. Whole pea seeds can be processed by different techniques such as drying, milling, soaking, and cooking to improve their functional properties. In addition, physicochemical and functional properties of pea starches and pea proteins can be improved by chemical, physical, enzymatic, and combined modification methods. Owing to the multiple bioactive ingredients in peas, the pea and its products exhibit various health benefits, such as antioxidant, anti-inflammatory, antimicrobial, anti-renal fibrosis, and regulation of metabolic syndrome effects. Peas have been processed into various products such as pea beverages, germinated pea products, pea flour-incorporated products, pea-based meat alternatives, and encapsulation and packing materials. Furthermore, recommendations are also provided on how to better utilize peas to promote their development as a sustainable and functional grain. Pea and its components can be further developed into more valuable and nutritious products.

IFNγ blockade in capillary leak site improves tumour chemotherapy by inhibiting lactate-induced endocytosis of vascular endothelial-cadherins.

IFNγ has long been recognised as a key mediator of tumour immunity and angiostasis. However, IFNγ modulation for cancer therapy is still unsuccessful due to its complex effects on various host cells. In this study, we found that treatment of Lewis lung carcinoma transplants with cisplatin often caused IFNγ-dependent tumour vascular damage. IFNγ induced endothelial glycolysis and lactate production, leading to enhanced endocytosis of vascular endothelial (VE)-cadherin and vessel leakage. We have also developed anti-IFNγ nanoparticles coated with a clot-binding peptide CREKA (CREKA-lipo-anti-IFNγ), which targets the fibrin-fibronectin complex that appears in the leaky site of damaged tumour blood vessels. Blocking IFNγ activity in the leakage site of capillaries using nanoparticles rescued VE-cadherin distribution on the endothelial cellular surface, promoted blood vessel integrity, and improved drug delivery. In conclusion, IFNγ blockade in capillary leak site protected tumour blood vessels from lactate-dependent VE-cadherin loss and enhanced drug delivery during chemotherapy, which provides a basis for tissue-specific IFNγ blockade for tumour therapy.

Transgelin promotes lung cancer progression via activation of cancer-associated fibroblasts with enhanced IL-6 release.

Cancer-associated fibroblasts (CAFs), the principal constituent of the heterogenous tumor microenvironment, have been shown to promote tumor progression; however, the underlying mechanism is still less clear. Here, we find that transgelin (TAGLN) protein levels increased in primary CAFs isolated from human lung cancer, compared with those in paired normal fibroblasts. Tumor microarrays (TMAs) revealed that increased stromal TAGLN levels correlates with more lymphatic metastasis of tumor cells. In a subcutaneous tumor transplantation model, overexpression of Tagln in fibroblasts also increased tumor cell spread in mice. Further experiments show that Tagln overexpression promoted fibroblast activation and mobility in vitro. And TAGLN facilitates p-p65 entry into the nucleus, thereby activating the NF-κB signaling pathway in fibroblasts. Activated fibroblasts promote lung cancer progression via enhancing the release of pro-inflammatory cytokines, especially interleukine-6 (IL-6). Our study revealed that the high levels of stromal TAGLN is a predictive risk factor for patients with lung cancer. Targeting stromal TAGLN may present an alternative therapeutic strategy against lung cancer progression.

S100A4-dependent glycolysis promotes lymphatic vessel sprouting in tumor.

Tumor-induced lymphangiogenesis promotes the formation of new lymphatic vessels, contributing to lymph nodes (LNs) metastasis of tumor cells in both mice and humans. Vessel sprouting appears to be a critical step in this process. However, how lymphatic vessels sprout during tumor lymphangiogenesis is not well-established. Here, we report that S100A4 expressed in lymphatic endothelial cells (LECs) promotes lymphatic vessel sprouting in a growing tumor by regulating glycolysis. In mice, the loss of S100A4 in a whole body (S100A4-/-), or specifically in LECs (S100A4ΔLYVE1) leads to impaired tumor lymphangiogenesis and disrupted metastasis of tumor cells to sentinel LNs. Using a 3D spheroid sprouting assay, we found that S100A4 in LECs was required for the lymphatic vessel sprouting. Further investigations revealed that S100A4 was essential for the position and motility of tip cells, where it activated AMPK-dependent glycolysis during lymphatic sprouting. In addition, the expression of S100A4 in LECs was upregulated under hypoxic conditions. These results suggest that S100A4 is a novel regulator of tumor-induced lymphangiogenesis. Targeting S100A4 in LECs may be a potential therapeutic strategy for lymphatic tumor metastasis.

A plant nonenveloped double-stranded RNA virus activates and co-opts BNIP3-mediated mitophagy to promote persistent infection in its insect vector.

Mitophagy that selectively eliminates damaged mitochondria is an essential mitochondrial quality control mechanism. Recently, mitophagy has been shown to be induced in host cells infected by a few animal viruses. Here, we report that southern rice black-streaked dwarf virus (SRBSDV), a plant nonenveloped double-stranded RNA virus, can also trigger mitophagy in its planthopper vector to prevent mitochondria-dependent apoptosis and promote persistent viral propagation. We find that the fibrillar structures constructed by the nonstructural protein P7-1 of SRBSDV directly target mitochondria via interaction with the mitophagy receptor BNIP3 (BCL2 interacting protein 3), and these mitochondria are then sequestered within autophagosomes to form mitophagosomes. Moreover, SRBSDV infection or P7-1 expression alone can promote BNIP3 dimerization on the mitochondria, and induce autophagy via the P7-1-ATG8 interaction. Furthermore, SRBSDV infection stimulates the phosphorylation of AMP-activated protein kinase (AMPK), resulting in BNIP3 phosphorylation via the AMPKα-BNIP3 interaction. Together, P7-1 induces BNIP3-mediated mitophagy by promoting the formation of phosphorylated BNIP3 dimers on the mitochondria. Silencing of ATG8, BNIP3, or AMPKα significantly reduces virus-induced mitophagy and viral propagation in insect vectors. These data suggest that in planthopper, SRBSDV-induced mitophagosomes are modified to accommodate virions and facilitate persistent viral propagation. In summary, our results demonstrate a previously unappreciated role of a viral protein in the induction of BNIP3-mediated mitophagy by bridging autophagosomes and mitochondria and reveal the functional importance of virus-induced mitophagy in maintaining persistent viral infection in insect vectors.Abbreviations: AMPK: AMP-activated protein kinase; ATG: autophagy related; BNIP3: BCL2 interacting protein 3; CASP3: caspase 3; dsRNA: double strand RNA; ER: endoplasmic reticulum; FITC: fluorescein isothiocyanate; FKBP8: FKBP prolyl isomerase 8; FUNDC1: FUN14 domain containing 1; GFP: green fluorescent protein; GST: glutathione S-transferase; padp: post-first access to diseased plants; Phos-tag: Phosphate-binding tag; PINK1: PTEN induced kinase 1; Sf9: Spodoptera frugiperda; SQSTM1: sequestosome 1; SRBSDV: southern rice black-streaked dwarf virus; STK11/LKB1: serine/threonine kinase 11; TOMM20: translocase of outer mitochondrial membrane 20; RBSDV: rice black-streaked dwarf virus; TUNEL: terminal deoxynucleotidyl dUTP nick end labeling; ULK1: unc-51 like autophagy activating kinase 1; VDAC1: voltage dependent anion channel 1.

Stearoyl-CoA Desaturase-1 dependent lipid droplets accumulation in cancer-associated fibroblasts facilitates the progression of lung cancer.

Rationale: Cancer-associated fibroblasts (CAFs) are the main components in the tumor microenvironment (TME) and facilitate lung cancer progression. Studies have reported that metabolic reprogramming can regulate the function of CAFs, especially abnormal lipid metabolism. Lipid droplets (LDs) are ubiquitous organelles that store neutral lipids and have a crucial role in lipid metabolism. However, little is known about the synthesis and functions of LDs in lung CAFs. Methods: TetO-EGFRL858R; CCSP-rtTA transgenic mouse model was used to establish a spontaneous pulmonary tumor model and investigate the accumulation of LDs in CAFs. The effect of LDs accumulation on the phenotype change of fibroblasts was estimated in vitro using mouse fibroblast cell lines. RNA sequencing, Western blotting, RT-PCR, and DNA-pull down were performed to determine the mechanism of LDs synthesis in fibroblasts. Results: We found that LDs were enriched in lung CAFs and induced the pro-tumoral phenotype of CAFs with increased expression of α-smooth muscle actin (α-SMA) and Collagen alpha-2 (I) chain (COL1A2). As the main regulator, hypoxia-inducible factor-1α (HIF-1α) was highly expressed in activated fibroblasts and increased the content of LDs. RNA-sequencing results showed that Stearoyl-CoA Desaturase1 (SCD1) was a downstream gene of HIF-1α, which upregulated the number of LDs in fibroblasts. Importantly, SCD1 inhibition reduced the growth of lung tumors, which was correlated with LDs decrease in CAFs. Analysis of human lung adenocarcinoma tissue chip revealed that CAFs with a high level of SCD1 were positively correlated with the expression of HIF-1α and poor survival in lung cancer patients. Conclusions: The HIF-1α/SCD1 axis regulates the accumulation of LDs in CAFs, which might represent a novel target for lung cancer therapy.

ZIP1+ fibroblasts protect lung cancer against chemotherapy via connexin-43 mediated intercellular Zn2+ transfer.

Tumour-stroma cell interactions impact cancer progression and therapy responses. Intercellular communication between fibroblasts and cancer cells using various soluble mediators has often been reported. In this study, we find that a zinc-transporter (ZIP1) positive tumour-associated fibroblast subset is enriched after chemotherapy and directly interconnects lung cancer cells with gap junctions. Using single-cell RNA sequencing, we identify several fibroblast subpopulations, among which Zip1+ fibroblasts are highly enriched in mouse lung tumours after doxorubicin treatment. ZIP1 expression on fibroblasts enhances gap junction formation in cancer cells by upregulating connexin-43. Acting as a Zn2+ reservoir, ZIP1+ fibroblasts absorb and transfer Zn2+ to cancer cells, leading to ABCB1-mediated chemoresistance. Clinically, ZIP1high stromal fibroblasts are also associated with chemoresistance in human lung cancers. Taken together, our results reveal a mechanism by which fibroblasts interact directly with tumour cells via gap junctions and contribute to chemoresistance in lung cancer.

Claudin-3 inhibits tumor-induced lymphangiogenesis via regulating the PI3K signaling pathway in lymphatic endothelial cells.

Claudin-3 is a tight junction protein that has often been associated with the progression and metastasis of various tumors. Here, the role of claudin-3 in tumor-induced lymphangiogenesis is investigated. We found an increased lymphangiogenesis in the B16F10 tumor in claudin-3 knockout mice, accompanied by augmented melanoma cell metastasis into sentinel lymph nodes. In vitro, the overexpression of claudin-3 on lymphatic endothelial cells inhibited tube formation by suppressing cell migration, resulting in restricted lymphangiogenesis. Further experiments showed that claudin-3 inhibited lymphatic endothelial cell migration by regulating the PI3K signaling pathway. Interestingly, the expression of claudin-3 in lymphatic endothelial cells is down-regulated by vascular endothelial growth factor C that is often present in the tumor microenvironment. This study indicates that claudin-3 plays an important role as a signaling molecule in lymphatic endothelial cell activity associated with tumor lymphangiogenesis, which may further contribute to melanoma metastasis.

The hnRNPK/A1/R/U Complex Regulates Gene Transcription and Translation and is a Favorable Prognostic Biomarker for Human Colorectal Adenocarcinoma.

Heterogeneous nuclear ribonucleoproteins (hnRNPs) are emerging as a crucially important protein family in tumors. However, it is unclear which family members are essential for cancer progression, and their diverse expression patterns and prognostic values are rarely reported. In this work, we found that the expression levels of hnRNPs were all upregulated in colon adenocarcinoma (COAD) and rectal adenocarcinoma (READ) tissues. Immunohistochemical staining revealed that hnRNPA1, hnRNPA2B1, hnRNPC, hnRNPK, hnRNPR, and hnRNPU are overexpressed in colorectal adenocarcinoma. Additionally, the promoter methylation levels of hnRNPs were significantly elevated or decreased, and multiple genetic alterations of hnRNPs were found in colorectal adenocarcinoma patients. Correlation analysis showed that the expression levels of hnRNPs were positively correlated with each other. Furthermore, we demonstrated that high expressions of hnRNPA1, hnRNPK, hnRNPR, and hnRNPU were associated with better overall survival rates for colorectal adenocarcinoma patients. The co-expression network and functional prediction analysis indicated that hnRNPK/A1/R/U was involved in cellular gene transcription and translation. Moreover, hnRNPK/A1/R/U complex was identified and confirmed by mass spectrometry and co-immunoprecipitation. RNA sequencing analysis revealed that the transcription factor hnRNPK regulated transcription and translation of related genes. Finally, through establishment of stable cell lines in vitro, we verified that hnRNPK was a favorable factor in human colorectal adenocarcinoma which promoted immune cell infiltration and inhibited tumor growth. Our findings illustrate that the hnRNPK/A1/R/U complex is a favorable prognostic biomarker for human colorectal adenocarcinoma. Targeting hnRNPK during transcription and translation could be a promising therapeutic strategy for colorectal adenocarcinoma treatment.

Tumor-derived exosomes drive pre-metastatic niche formation in lung via modulating CCL1+ fibroblast and CCR8+ Treg cell interactions.

BACKGROUND: Since the lung is one of the most common sites for cancer metastasis, it could provide a suitable microenvironment for pre-metastatic niche (PMN) formation to facilitate tumor cell colonization. Regulatory T cells (Tregs) are an immunosuppressive cell type found ubiquitously in tumors and may play a crucial role in PNM formation. In this study, we investigated tumor-derived exosome (TDE)-induced Treg differentiation in the lung PMN as well as the underlying mechanisms. METHODS: TDEs were isolated from the Lewis lung carcinoma cell line (LLC-exo) and their effects on mouse pulmonary fibroblasts was investigated in vitro as well as on lung tumor formation and metastasis in a pre-injected mouse model. Immune cell populations in the lung were analyzed by flow cytometry. Expression of CCL1 and CCR8 was evaluated by immunofluorescence staining, qRT-PCR and Western blot analyses. Cytokine expression was measured using mouse cytokine arrays and ELISA. RESULTS: The number of CD4+ FoxP3+ Tregs was significantly increased in lungs in a LLC-exo pre-injected mouse model. Lung fibroblasts secreted increased amounts of CCL1 after co-culture with LLC-exo, which induced Treg differentiation by activating its specific receptor CCR8, ultimately contributing to the establishment of an immunologically tolerant PMN. Moreover, inhibiting the release of LLC-exo by GW4869, or blocking the CCL1-CCR8 axis using AZ084, suppressed Tregs differentiation and tumor metastasis in the lung. CONCLUSIONS: Collectively, our study provides a novel mechanism by which Tregs are activated to form an immunologically tolerant PMN and demonstrates a critical link among lung fibroblasts, Tregs and metastatic tumor cells.

Paclitaxel treatment enhances lymphatic metastasis of B16F10 melanoma cells via CCL21/CCR7 axis.

Chemotherapeutic drugs have been successfully used to treat several cancers, including melanoma. However, metastasis occasionally occurs after chemotherapy. Here, we reported that paclitaxel (PTX) treatment for B16F10 tumour in mice led to an enhanced lymphatic metastasis of the melanoma cells, although a significant inhibition of tumour growth at the injection site was observed. Further study demonstrated that PTX upregulated the expression of C-C chemokine receptor type 7 (CCR7) in B16F10 cells, enhancing their migration through the activation of JNK and p38 signalling pathways. Loss of CCR7 or blockade of C-C motif chemokine ligand 21 (CCL21)/CCR7 axis abolished the pro-migration effect of PTX on B16F10 melanoma cells. Importantly, combination of PTX and CCR7 mAb could simultaneously delay the tumour growth and reduce the lymphatic metastasis in B16F10 melanoma. The blockade of CCL21/CCR7 axis may collectively serve as a strategy for lymphatic metastasis in some melanoma after chemotherapy.

Inhibiting collagen I production and tumor cell colonization in the lung via miR-29a-3p loading of exosome-/liposome-based nanovesicles.

The lung is one of the most common sites for cancer metastasis. Collagens in the lung provide a permissive microenvironment that supports the colonization and outgrowth of disseminated tumor cells. Therefore, down-regulating the production of collagens may contribute to the inhibition of lung metastasis. It has been suggested that miR-29 exhibits effective anti-fibrotic activity by negatively regulating the expression of collagens. Indeed, our clinical lung tumor data shows that miR-29a-3p expression negatively correlates with collagen I expression in lung tumors and positively correlates with patients' outcomes. However, suitable carriers need to be selected to deliver this therapeutic miRNA to the lungs. In this study, we found that the chemotherapy drug cisplatin facilitated miR-29a-3p accumulation in the exosomes of lung tumor cells, and this type of exosomes exhibited a specific lung-targeting effect and promising collagen down-regulation. To scale up the preparation and simplify the delivery system, we designed a lung-targeting liposomal nanovesicle (by adjusting the molar ratio of DOTAP/cholesterol-miRNAs to 4:1) to carry miR-29a-3p and mimic the exosomes. This liposomal nanovesicle delivery system significantly down-regulated collagen I secretion by lung fibroblasts in vivo, thus alleviating the establishment of a pro-metastatic environment for circulating lung tumor cells.