IntroductionKawasaki disease (KD) is an acute systemic vasculitis with an unknown etiology, and the underlying molecular mechanisms of vascular inflammation remain unclear. Mononuclear phagocyte activation is a prominent feature of the acute phase, but the upstream regulators of this process remain incompletely understood. This study aimed to investigate the role of heme oxygenase-1 in mononuclear phagocyte inflammation in KD.MethodsIntegrating single-cell RNA sequencing (scRNA-Seq) and bulk RNA sequencing (bulk RNA-Seq) data, we analyzed differences in peripheral blood immune cell composition and key molecular expression profiles in children with KD to identify potential targets linked to mononuclear phagocyte activation. We collected clinical samples from KD patients to measure HMOX1 expression in peripheral blood mononuclear cells (PBMCs) and corresponding changes in serum inflammatory cytokines for validation. A KD mouse model was established via intraperitoneal injection of CAWS, and a separate therapeutic model was generated using SnMP. We then employed western blot, hematoxylin and eosin (HE) staining, cardiac ultrasound, and immunohistochemical staining to assess HMOX1 expression, coronary artery inflammatory infiltration, changes in coronary artery internal diameter, and macrophage infiltration.ResultsIntegrated analysis of single-cell and bulk RNA sequencing data showed elevated HMOX1 expression in mononuclear phagocytes from KD patients, correlating with reactive oxygen species and nuclear factor kappa B signaling pathways. In clinical samples, HMOX1 expression was increased in peripheral blood mononuclear cells, and serum tumor necrosis factor-alpha levels were elevated. In KD murine models, perivascular inflammatory infiltration, mononuclear phagocyte infiltration, and increased expression of HMOX1 in mononuclear phagocytes were observed, accompanied by elevated tumor necrosis factor-alpha expression. Notably, treatment with SnMP attenuated these pathological changes.ConclusionsOur study suggests that HMOX1 is upregulated in mononuclear phagocytes during acute Kawasaki disease and is associated with activation of inflammatory pathways. The HMOX1 inhibitor SnMP alleviated vascular inflammatory injury, indicating its potential as a therapeutic target for KD.

Transfer RNA-derived small RNAs (tsRNAs) have been implicated in tumor progression and immune regulation in recent years. However, the specific role of tRNA halves (tiRNAs), a subclass of tsRNAs, in modulating immunotherapy response remains unexplored. In this study, 5’-tiRNAGly levels were examined in gastric cancer (GC) patients and found to be upregulated, especially in non-responders to anti-PD-1 therapy. Elevated 5’-tiRNAGly levels were also associated with diminished oxoglutarate dehydrogenase-like (OGDHL) expression. Further exploration revealed that 5’-tiRNAGly bound to DLST and promoted OGDHL destabilization, whereas targeted inhibition of 5’-tiRNAGly restored OGDHL stability through succinylation at lysine 910, enhanced tricarboxylic acid (TCA) cycle activity, and reduced glutamine-derived metabolic reprogramming. Additionally, 5’-tiRNAGly was found to decrease the activity of α-ketoglutarate dehydrogenase and inhibit succinylation of histone H3 at lysine 79 (H3K79suc), thereby downregulating PD-L1 transcription and reducing therapeutic responsiveness to PD-1 inhibitors. Conversely, restoration of this epigenetic modification upon 5’-tiRNAGly inhibition facilitated PD-L1 transcription, thereby sensitizing tumors to anti-PD-1 therapy. Our findings indicate that targeting 5’-tiRNAGly may represent a promising strategy to enhance responsiveness to anti-PD-1 therapy in GC patients.

OBJECTIVE:This study explores the relationship between T helper 17 (Th17)/regulatory T (Treg) cell balance, human umbilical cord mesenchymal stem cells (hUC-MSCs), and immune dysregulation in Henoch-Schönlein purpura (HSP). METHODS:Peripheral blood and clinical data were collected from children with acute HSP and healthy controls. Th17/Treg-related transcription factors and cytokines were measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA). In vitro, human umbilical vein endothelial cells were stimulated with HSP serum and co-cultured with hUC-MSCs, with or without the signal transducer and activator of transcription 3 (STAT3) agonist colivelin TFA. STAT3 signaling, interleukin-6 (IL-6) expression, and endothelial migration were analyzed. In vivo, an ovalbumin-induced HSP rat model was treated with hUC-MSCs or stem cells plus colivelin TFA, followed by evaluation of pathological injury, STAT3 activation, and splenic Th17/Treg ratios. RESULTS:Children with HSP exhibited significant Th17/Treg imbalance, with elevated RORγt and IL-17 and decreased FOXP3 and IL-10 (P < 0.05). In vitro, stem cells suppressed IL-6/STAT3 signaling, reduced STAT3 phosphorylation, and promoted endothelial repair, whereas colivelin TFA abolished these effects. In the rat model, stem cell transplantation alleviated inflammation in skin, kidney, joint, and intestinal tissues by downregulating the IL-6/STAT3/RORγt axis and restoring Th17/Treg balance; these benefits were negated by colivelin TFA. CONCLUSION:Th17/Treg imbalance is an immunopathological feature of HSP. hUC-MSCs restore immune homeostasis by inhibiting STAT3 signaling, highlighting STAT3 as a potential therapeutic target and supporting further investigation of stem cell-based therapy.

BACKGROUND:Hepatocellular carcinoma (HCC) is a globally prevalent malignancy associated with high morbidity and mortality. Transfer RNA (tRNA)-derived small RNAs (tsRNAs), a class of small non-coding RNAs originating from tRNA, have emerged as potential therapeutic targets in cancers, including HCC. However, the specific tsRNAs involved in HCC and their precise mechanisms remain largely unknown. In this study, we identify and characterize specific tsRNAs involved in the development and progression of HCC, discovering their potential as novel biomarkers for early detection and potential therapeutic targets. AIM:To investigate differentially expressed tsRNAs in HCC, identify potential biomarkers, and elucidate the functions and mechanisms of tsRNAs in HCC. METHODS:Differentially expressed tsRNAs in Barcelona Clinic Liver Cancer 0/A-stage HCC tissues were identified through high-throughput sequencing. Agarose gel electrophoresis, Sanger sequencing, and quantitative polymerase chain reaction were conducted to detect 5'-tRNA halve (tiRNA)-lysine (Lys)-CTT in tissues and serum samples. The diagnostic performance of 5'-tiRNA-Lys-CTT was evaluated using receiver operating characteristic analysis. HCC cell proliferation was examined using the Cell Counting Kit-8 assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine staining. Additionally, the migratory capability of HCC cells was investigated using Transwell assays. RESULTS:The 5'-tiRNA-Lys-CTT demonstrated excellent stability and can be easily detected. Its expression was significantly upregulated in 50 HCC tissues, 110 HCC serum samples, and 5 HCC cell lines vs control groups, and the differences were all significant. This elevated expression was strongly associated with clinicopathological characteristics, particularly tumor size, Barcelona Clinic Liver Cancer stage, and cirrhosis of the liver. Receiver operating characteristic analysis revealed superior detection efficiency of 5'-tiRNA-Lys-CTT exhibits for early-stage HCC compared to established markers. Functional assays revealed that 5'-tiRNA-Lys-CTT overexpression promoted cell proliferation and migration, while its inhibition had the opposite effect. Bioinformatics predictions suggest that 5'-tiRNA-Lys-CTT may influence the development and progression of liver cancer by targeting downstream mRNA via metabolic pathways, cancer pathways, and HCC-specific pathways. CONCLUSION:The 5'-tiRNA-Lys-CTT levels were higher in early HCC patients. 5'-tiRNA-Lys-CTT is a promising diagnostic biomarker for early-stage HCC and may play an oncogenic role in HCC by interacting with downstream mRNA targets via specific pathways.

Gastric cancer (GC) is globally recognized as one of the most widespread malignant tumors. As the symptoms of patients with early GC are ambiguous, the majority of patients are given a diagnosis of advanced GC. Therefore, this necessitates the search for new biomarkers to be utilized in the early diagnosis and screening of GC. Enhancer RNA (eRNA) is a non-coding RNA in transcription by enhancers that is tumor-specific and has a critical function in cancer progression. Our research investigates new eRNAs as bio-diagnostic markers for GC. Four eRNAs with good differential expression in GC were screened by TCGA and University of California, Santa Cruz databases. Quantitative real-time PCR was utilized for testing the level of RASSF8-AS1. The diagnostic effect of RASSF8-AS1 was evaluated using the receiver operating characteristic (ROC). Functional experiments were used to detect the ability of RASSF8-AS1 to affect the metastasis and proliferation in GC cells. The expression of RASSF8-AS1 was obviously elevated in both GC tissues and serum, whereas it was decreased in the serum levels of postoperative GC patients. ROC showed that RASSF8-AS1 was more diagnostically efficient than common diagnostic biomarkers for GC and that diagnostic effectiveness could be better than combining them. The findings of in vitro experiments showed that knocking down the level of RASSF8-AS1 clearly suppressed the ability of growth and metastasis in GC cells. Studies have shown that serum RASSF8-AS1 has the potential to contribute to the progression of GC as a biomarker for diagnosis and prognostic monitoring of GC.

OBJECTIVES:Gastric cancer (GC) is a global health challenge due to its asymptomatic early stages, low sensitivity of traditional serum biomarkers, and the invasiveness of endoscopy, resulting in delayed diagnosis and poor prognosis. The expression levels of tRNA-derived small RNAs (tsRNAs) significantly influence the emergence and development of malignancies. This study focused on the potential of tsRNAs as serum biomarkers for diagnosing GC. METHODS:Quantitative real-time PCR was used to measure 5'tRF-Lys expression levels, validated by agarose gel electrophoresis and Sanger sequencing. Kaplan-Meier survival curves assessed the association between 5'tRF-Lys expression levels and patient outcomes, while receiver operating characteristic (ROC) curves evaluated diagnostic accuracy. ROC curves showed that 5'tRF-Lys outperformed traditional serum biomarkers, and combining these markers can enhance diagnostic accuracy. RESULTS:The expression level of 5'tRF-Lys effectively differentiated GC patients from gastritis patients and healthy subjects. 5'tRF-Lys expression is negatively correlated with the T stage, lymph node metastasis, tumor-node-metastasis stage, neuro/vascular invasion, and positively correlated with tumor differentiation. Patients with low serum 5'tRF-Lys had a lower survival rate. CONCLUSIONS:5'tRF-Lys shows promise as a sensitive and specific biomarker for GC, including early-stage detection and survival prognosis, offering potential clinical applications.

Since gastric cancer (GC) shows no apparent signs in its early stages, most patients are diagnosed later with a poor prognosis. We therefore seek more sensitive and specific GC biomarkers. Small RNAs formed from tRNAs represent a novel class of non-coding RNAs that are highly abundant in bodily fluids and essential to biological metabolism. This study explores the potential of i-tRF-AsnGTT in gastric cancer diagnostics. To begin with, we sequenced i-tRF-AsnGTT using high-throughput methods. i-tRF-AsnGTT expression levels in GC were determined using real-time fluorescence polymerase chain reaction. Agarose gel electrophoresis, Sanger sequencing, and repeated freezing and thawing were performed to verify molecular properties. A correlation was found between clinical and pathological parameters and i-tRF-AsnGTT expression levels through the χ2 test, and receiver operating characteristic was used to analyze its diagnostic value in GC. In serum, i-tRF-AsnGTT has a low and stable expression level. It can differentiate between patients with gastric cancer and gastritis and healthy donors with better diagnostic efficacy. In combination with clinicopathological parameters, i-tRF-AsnGTT correlates with tumor differentiation; infiltration depth of tumors; tumor, node, metastasis stage; lymph node metastases; and neural/vascular invasion. Serum i-tRF-AsnGTT expression is low in GC patients. Serum from postoperative patients shows increased i-tRF-AsnGTT expression levels. Potentially, this could be used as a biomarker to help diagnose gastric cancer and monitor its prognosis.

Gastric cancer is one of the malignant tumors with the highest morbidity and mortality rates worldwide. Yet, there is a lack of diagnostic markers with high sensitivity in the clinic. tRNA-derived small RNAs are a novel type of non-coding small RNAs, which are abundant in tumor cells and body fluids. In this study, we explored the potential of 3'-tRFArg as a tumor marker for the diagnosis of GC. Differential expression of 3'-tRFArg was screened by high-throughput sequencing, and Quantitative real-time PCR confirmed its low expression in GC serum with good stability. Differential expression of serum 3'-tRFArg could distinguish between GC patients, gastritis patients, and healthy donors and was significantly correlated with clinical pathological features such as tumor differentiation, lymph node metastasis, and TNM staging. The receiver operating characteristic curve showed that 3'-tRFArg had a higher diagnostic value compared with conventional biomarkers, especially in the diagnosis of early gastric cancer. In conclusion, our results suggest that 3'-tRFArg can serve as a highly sensitive biomarker with a certain value for monitoring tumor development and prognosis.

OBJECTIVES:To investigate the role and mechanism of copper overload-mediated endoplasmic reticulum stress (ERS) in vascular endothelial injury in Kawasaki disease (KD). METHODS:Four-week-old male C57BL/6 mice were randomly divided into four groups: control, KD, KD plus copper chelator tetrathiomolybdate (TTM), and KD plus ERS inhibitor AMG PERK 44 (AMG) (n=20 per group). A KD mouse model was established using Candida albicans extract. Human umbilical vein endothelial cells (HUVECs) were divided into control (intervention with healthy children's serum), KD (intervention with KD patients' serum), and KD+TTM (intervention with KD patients' serum plus 20 µmol/L TTM). Copper deposition in mouse heart tissue was assessed using rubeanic acid staining. Vascular pathological changes were observed using hematoxylin-eosin staining and measurement of abdominal aortic diameter and area. ERS activation was detected by transmission electron microscopy and immunofluorescence. HUVEC viability, apoptosis, and functional changes were evaluated using CCK8, flow cytometry, cell scratch assay, and angiogenesis experiments. ERS marker protein expression levels were measured by Western blot. RESULTS:Compared to the KD group, the KD+TTM and KD+AMG groups showed reduced copper deposition in the vascular wall, decreased swelling of coronary endothelial cells and endoplasmic reticulum, reduced inflammatory cell infiltration, and less abdominal aortic lesion expansion. The abdominal aortic diameter and area, and the fluorescence intensity of ERS marker proteins (GRP78 and CHOP) were significantly lower (P<0.05). Compared to the KD group, the KD+TTM group exhibited increased cell viability, tube number, and scratch healing rate, along with decreased apoptosis rate and expression of ERS marker proteins (GRP78, CHOP, ATF6, and p-PERK) (P<0.05). CONCLUSIONS:Copper overload aggravates vascular endothelial injury in KD by activating the ERS pathway. TTM can exert protective effects on the endothelium by regulating copper metabolism and inhibiting the ERS pathway.

INTRODUCTION:Gastric cancer (GC) is a lethal malignant tumor necessitating high-sensitivity detection to improve diagnostic accuracy and the prognosis of patients. Alterations in long noncoding RNAs can influence cancer progression through various mechanisms. Our study tried to explore the potential of STARD4 antisense RNA 1 (STARD4-AS1) as a GC biomarker and its mechanism of action in GC development. METHODS:Pan-cancer analysis using The Cancer Genome Atlas database identified STARD4-AS1. Serum STARD4-AS1 levels in patients with GC were measured by quantitative real-time PCR, and diagnostic efficiency was assessed using receiver operating characteristic curves. Functional inactivation experiments and western blotting evaluated the biological role of STARD4-AS1 in GC cells. Bioinformatics analysis explored its potential role in GC immunotherapy and underlying mechanisms. RESULTS:Pan-cancer analysis revealed lower overall survival in GC patients with higher STARD4-AS1 expression. Quantitative real-time PCR confirmed the reproducibility and stability of STARD4-AS1 as a marker. Serum STARD4-AS1 levels in patients with GC were significantly higher than those in healthy subjects and gastritis patients. Receiver operating characteristic analysis demonstrated that STARD4-AS1 outperformed carcinoembryonic antigen, carbohydrate antigen 199 , and carbohydrate antigen 724 in differentiating GC from gastritis, with optimal diagnostic power when combined with these markers. Knockdown of STARD4-AS1 inhibited GC cell proliferation and metastasis and inhibited the epithelial-mesenchymal transition process. Biosignature prediction indicated that higher STARD4-AS1 expression could evaluate prognosis, as well as regulate GC progression through phosphatidylinositol-mediated signaling, and transmembrane receptor protein tyrosine phosphatase signaling pathway. DISCUSSION:Serum STARD4-AS1 may serve as a diagnostic biomarker and oncogene function for GC for improving diagnosis, monitoring progression, and evaluating prognosis of GC.

Kawasaki disease (KD) is an immune vasculitis of unknown origin, characterized by transient inflammation. The activation of the cGAS-STING pathway, triggered by mitochondrial DNA (mtDNA) release, has been implicated in the onset of KD. However, its specific role in the progression of inflammation during KD's acute phase remains unclear. We measured mtDNA and 2’3’-cGAMP expression in KD patient serum using RT-qPCR and ELISA. A murine model of KD was induced by injecting Lactobacillus casei cell wall extract (LCWE), after which cGAS-STING pathway activation and inflammatory markers were assessed via immunohistochemistry, western blot, and RT-qPCR. Human umbilical vein endothelial cells (HUVECs) were treated with KD serum and modulators of the cGAS-STING pathway for comparative analysis. Mitochondrial function was evaluated using Mitosox staining, mPTP opening was quantified by fluorescence microscopy, and mitochondrial membrane potential (MMP) was determined with JC-1 staining. KD patient serum exhibited increased mtDNA and 2’3’-cGAMP expression, with elevated levels of pathway-related proteins and inflammatory markers observed in both in vivo and in vitro models. TEM confirmed mitochondrial damage, and further studies demonstrated that inhibition of mPTP opening reduced mtDNA release, abrogated cGAS-STING pathway activation, and mitigated inflammation. These findings indicate that mtDNA released through the mPTP is a critical activator of the cGAS-STING pathway, contributing significantly to KD-associated inflammation. Targeting mtDNA release or the cGAS-STING pathway may offer novel therapeutic approaches for KD management.

OBJECTIVES:To study the role and mechanism of platelet-derived growth factor BB (PDGF-BB) on platelet production in Kawasaki disease (KD) mice and human megakaryocytic Dami cells through in vitro and invivo experiments.METHODS:ELISA was used to measure the expression of PDGF in the serum of 40 children with KD and 40 healthy children. C57BL/6 mice were used to establish a model of KD and were then randomly divided into a normal group, a KD group, and an imatinib group (30 mice in each group). Routine blood test was performed for each group, and the expression of PDGF-BB, megakaryocyte colony forming unit (CFU-MK), and the megakaryocyte marker CD41 were measured. CCK-8, flow cytometry, quantitative real-time PCR, and Western blot were used to analyze the role and mechanism of PDGF-BB in platelet production in Dami cells.RESULTS:PDGF-BB was highly expressed in the serum of KD children (P<0.001). The KD group had a higher expression level of PDGF-BB in serum (P<0.05) and significant increases in the expression of CFU-MK and CD41 (P<0.001), and the imatinib group had significant reductions in the expression of CFU-MK and CD41 (P<0.001). In vitro experiments showed that PDGF-BB promoted Dami cell proliferation, platelet production, mRNA expression of PDGFR-β, and protein expression of p-Akt (P<0.05). Compared with the PDGF-BB group, the combination group (PDGF-BB 25 ng/mL + imatinib 20 μmol/L) had significantly lower levels of platelet production, mRNA expression of PDGFR-β, and protein expression of p-Akt (P<0.05).CONCLUSIONS:PDGF-BB may promote megakaryocyte proliferation, differentiation, and platelet production by binding to PDGFR-β and activating the PI3K/Akt pathway, and the PDGFR-β inhibitor imatinib can reduce platelet production, which provides a new strategy for the treatment of thrombocytosis in KD.

Glycerophospholipid signal and fatty acid metabolism are closely related to the occurrence and progression of tumours, and metabolic reprogramming caused by hydrolytic enzymes plays an important role in gastric cancer (GC). Here, we performed whole transcriptome sequencing and combined qRT-PCR to screen out the significantly high expression of fatty acid amide hydrolase (FAAH) in GC tissues, which was further verified in both TCGA and Oncomine databases. Functional tests confirmed that FAAH played an oncogene role in GC, and silencing FAAH could delay tumour growth, inhibit tumour metastasis, and promote cell apoptosis both in vitro and in vivo. FAAH-mediated lipid metabolism reprogramming through coordinated regulation of arachidonoyl ethanolamide (AEA)/lysophosphatidic acid (LPA) signalling and activated the cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) axis to promote GC progression. Luciferase reporter assay and immunofluorescence-fluorescence in situ hybridization (IF-FISH) were applied to validate the interactions of miR-1275/FAAH. Overexpression and knockdown of miR-1275 in vitro could indirectly modulate the above lipid signalling by targeting FAAH, thereby affecting GC progression. Our study indicates that deregulated FAAH is a key lipid signal and the miR-1275/FAAH/AEA/LPA axis can serve as a diagnostic biomarker for GC or as a target for therapy development.

Taurine upregulated gene 1 (TUG1) has been implicated in the onset and progression of various malignancies. The current study aimed to evaluate the biological function and potential mechanisms of TUG1 in multiple myeloma (MM) progression. TUG1 knockdown in MM cells was investigated in vitro and in vivo to evaluate the role of TUG1. We also predicted the transcription factor (TF) that bound to TUG1 together with the downstream target genes of the TUG1-TF interaction, and evaluated the regulatory mechanism of TUG1 in cell assays. TUG1 knockdown reduced the cell's proliferative and migratory capabilities while increasing apoptosis and bortezomib sensitivity in vitro and inhibiting tumorigenesis in vivo. TUG1 was found in the nucleus of MM cells and was found to be positively regulated by the TF-YY1. Further in vitro mechanistic investigations indicated that the YY1-TUG1 complex targeted YOD1 to regulate MM progression.

Vascular endothelial inflammation and endothelial dysfunction are the main causes of endothelial injury in Kawasaki disease (KD). Human umbilical cord–derived mesenchymal stem cells (Huc-MSCs) have multiple functions in immune regulation. This study examined whether Huc-MSCs inhibited endothelial inflammation and improved endothelial function in KD through constructing cell and in vivo animal KD vasculitis models. The pyroptosis factor NOD-like receptor protein 3 (NLRP3) was involved in the inflammatory process in the acute phase of KD. After tail vein injection of Huc-MSCs, inflammatory cell infiltration and the expression of pyroptosis-related proteins in the LCWE-induced KD mouse vasculitis model were significantly reduced. In vitro, NLRP3-dependent pyroptosis successfully induced human umbilical vein endothelial cell (HUVEC) damage. Huc-MSCs effectively increased the abilities of impaired HUVECs to proliferate, migrate, invade, and form vessel-like tubes, while inhibiting their apoptosis, suggesting that Huc-MSCs can reduce inflammation and improve vascular endothelial function by inhibiting the NLRP3-dependent pyroptosis pathway in KD, providing a possibility and novel target for KD endothelial injury and dysfunction.

Objective:To investigate the expression of hsa_circ_0000437 in the serum of patients with gastric cancer and its clinical value.Methods:The serum samples from 80 patients (57 males and 23 females) with pathologically confirmed gastric cancer (GC), 50 gastric benign disease (28 males and 22 females) and 80 healthy controls (46 males and 34 females) were collected from October 2018 to December 2020 in Affiliated Hospital of Nantong University.Serum samples from 35 of 80 gastric cancer patients after operation were collected. The expression of serum hsa_circ_0000437 was determined by real-time fluorescent quantitative PCR (RT-qPCR). Serum carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA 199) and carbohydrate antigen 724 (CA724) were determined by chemiluminescence method.Comparisons of serum hsa_circ_0000437 between groups were performed by Mann-Whitney U test.The correlation between serum expression of hsa_circ_0000437 in gastric cancer patients and its clinical pathological characteristics was performed by χ 2 test.Receiver operating characteristic (ROC) curve and the area under the curve of ROC (AUC) were used to evaluate their diagnosis efficiency. Kaplan-Meier survival curve analysis was used to analyze the relationship between the expression level of serum hsa_circ_0000437 and the prognosis of patients. Results:The relative expression of hsa_circ_0000437 in GC, gastric benign disease, healthy controls were 2.252 (1.235, 4.765), 1.598(1.139, 1.982) and 1.000 (0.818, 1.385) respectively.The relative expression of hsa_circ_0000437 in GC was significantly higher than that in gastric benign disease ( P<0.001) and healthy controls ( P<0.001). The difference between gastric benign disease and healthy controls was also statistically significant ( P<0.001).The differences of serum hsa_circ_0000437 expression in GC patients between T stage, N stage, and tumor differentiation were statistically significant. The AUC of hsa_circ_0000437, CEA, CA199 and CA724 in GC patients were 0.863, 0.619, 657 and 0.608 respectively compared with healthy controls. The AUC of above four-parameter panel was 0.892 and the sensitivity was up to 97.5% (78/80). Kaplan-Meier survival curve showed that the overall survival rate of patients with high serum hsa_circ_0000437 expression was significantly lower than that of patients with low expression ( P=0.008). Conclusion:Serum hsa_circ_0000437 could be a biomarker for the auxiliary diagnosis and prognosis of GC.

Cellular communication between gastric cancer (GC) cells with different metastatic potentials and microenvironments and resultant cancer progression is not fully understood. Circular RNAs (circRNAs) and exosomal circRNAs are known to play extremely important regulatory roles in GC occurrence and progression. Here, we revealed significant differences in coronin-like actin-binding protein 1C (CORO1C) derived circRNA hsa_circ_0000437 between GC and para-cancer tissues. Hsa_circ_0000437 regulated GC cell proliferation, invasion, migration and apoptosis by targeting Ser/Arg-rich splicing factor 3 (SRSF3) and inhibiting programmed cell death 4 (PDCD4). The ectopic expression of hsa_circ_0000437 dramatically promoted tumor growth in nude mice in vivo. Furthermore, both gain-of-function and loss-of-function experiments demonstrated that hsa_circ_0000437 promoted human lymphatic endothelial cells (HLECs) invasion, migration, and tube formation in vitro and also promoted lymphangiogenesis and lymph node metastasis (LNM) in popliteal LNM model in vivo, when it was enriched in GC-secreted exosomes and transferred into HLECs. Mechanistically, exosomal hsa_circ_0000437 induced LNM via HSPA2-ERK signaling pathway independent of VEGF-C. Clinical data showed that exosomal hsa_circ_0000437 was enriched in the serum of GC patients, which was associated with LNM. In summary, these findings highlight the potential role of hsa_circ_0000437 as an outcome biomarker in GC patients with LNM, which may provide a novel target for GC therapy.

Emerging evidence indicates that exosomes can be used as a potential biomarker for monitoring diseases, including cancer. However, enhancing the sensing performance in terms of convenience and sensitivity remains an urgent demand for exosomes detection. In this study, a pH-sensitive colorimetric biosensing strategy was developed for exosomes detection by integrating stimuli-responsive DNA microcapsules and acetylcholinesterase to produce acetic acid. The constructed DNA microcapsules consisted of DNA shells crosslinked by anti-CD63 aptamers and loaded with acetylcholinesterase. With exosomes addition, an energetically stabilized aptamer-CD63 compound was produced and microcapsules dissociated due to the reaction of surface protein CD63 of exosomes and aptamer of CD63, resulting in the release of encapsulated AChE. Through a simple centrifugation separation, unreacted DNA microcapsules were removed and the supernatant containing released acetylcholinesterase collected, which was then used for colorimetric exosomes detection through the ability of acetylcholinesterase to hydrolyze acetylcholine to release acetic acid. The resulting decreased solution pH was detected with phenol red indicator, with the sharp color transition conveniently by naked eye. Exosomes quantification was also achieved using the solution's absorption intensity ratio of 558 vs. 432 nm. The linear range was from 2.0 × 103 to 5.0 × 105 particles/μL, and the limit of detection and limit of quantification were 1.2 × 103 particles/μL and 2.2 × 103 particles/μL, respectively. In addition, this proposed strategy for exosomes detection showed a relative standard deviation of 3.1% and high recovery efficiency (>94%), exhibiting a bright application future in exsomes analysis.