Endometrial cancer (EC) is a common gynaecological cancer worldwide. Exosomes, secreted by living cells and detected in various body fluids, can exchange information between organs and compartments ...to affect cellular functions, such as proliferation, apoptosis, migration and angiogenesis. We hypothesise that plasma exosomal contents are altered during cancer progression and promote cancer growth and angiogenesis by delivering biomolecules to cancer and vascular endothelial cells. In this study, circulating exosomes derived from EC patients and age-matched healthy people were acquired by commercial kits. Cell counting kit-8, Transwell and Matrigel tube formation assays showed that circulating exosomes from EC patients promote EC cell growth and human umbilical vein endothelial cell (HUVEC) angiogenesis. Next, proteomic analysis and ELISA revealed that plasma exosomal lectin galactoside-binding soluble 3 binding protein (LGALS3BP) increased during EC progression. Moreover, to explore the function of exosomal LGALS3BP, we acquired exosomes containing high levels of LGALS3BP by overexpressing LGALS3BP in human embryonic kidney 293 cells, and we demonstrated that highly contained exosomal LGALS3BP contributed to EC cell proliferation and migration and HUVEC functions via the activation of the PI3K/AKT/VEGFA signalling pathway both in vitro and in vivo. Finally, high LGALS3BP expression was observed in human EC tissue, which indicated a poor prognosis. In addition, immunohistochemical analysis of human EC tissues revealed that LGALS3BP expression was correlated with VEGFA expression and blood vessel density. Hence, we proposed that plasma exosomes containing LGALS3BP contributed to EC growth and angiogenesis during EC progression, which also provided a novel perspective on EC diagnosis and prognosis.
To investigate the correlation between colorectal polyps (CRP) and Helicobacter pylori (H. pylori) infection, and the correlation between CRP and the expression of phosphorylated ribosomal protein S6 ...kinase (p-S6K1). Besides, its related influencing factors were determined in the present study. A total of 191 subjects who underwent colonoscopy in our hospital from January 2020 to February 2022 were selected for this study. Among them, 141 patients were diagnosed with CRP, and the other 50 subjects were no significant colorectal abnormalities. 141 CRP patients were divided into H. pylori-positive group (n = 89) and H. pylori-negative group (n = 52) according to the results of the H. pylori test. The expression of p-S6K1 in CRP tissue was detected. The relationship between the p-S6K1 expression and the clinicopathological characteristics of CRP patients was analyzed. The logistic analysis of factors influencing the occurrence of CRP was performed. There were significant differences in pathological type, site of disease, the number and size of polyps between the H. pylori negative group and the H. pylori positive group (P < 0.001, P = 0.037, P = 0.042 and P = 0.039). The percentage of the p-S6K1 positive expression in polyp tissues was higher than that in normal tissue and parapolyp tissues (P < 0.001). The p-S6K1 negative group showed significant difference in the number and pathological type of polyps and the presence or absence of a pedicle as compared with the p-S6K1 positive group (P = 0.006, P < 0.001 and P = 0.012). Logistic multifactor analysis showed that BMI, H. pylori infection, smoking history, ApoB, Lp(a) and the p-S6K1 positive expression were all risk factors for the development of CRP (P = 0.025, P = 0.020, P = 0.010, P = 0.005, P = 0.043 and P < 0.001). H. pylori infection was closely related to the pathological type, location, and the number and size of CRP. p-S6K1 was highly expressed in CRP, and was positively related to the number, the pathological type and pedicle of polyps. H. pylori infection and the positive p-S6K1 expression were independent risk factors for CRP. By exploring the association between H. pylori infection as well as p-S6K1 and CRP, it is hoped that it will help to formulate a more rigorous colorectal cancer screening program for H. pylori-positive individuals, and at the same time find a new direction for the prevention of CRP and colorectal cancer, and provide some help for future research.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In ovarian cancer, CD44+/CD117+ stem cells, also known as cancer‐initiating cells (CICs), are highly proliferative, have a low degree of differentiation, and are resistant to chemotherapeutics. ...Therefore, the CD44+/CD117+ subpopulation is thought to be an important target for novel therapeutic strategies. In this study, we investigated the role of microRNA‐199a (miR‐199a) in ovarian cancer stem cells. Luciferase reporter gene assays confirmed that miR‐199a targets CD44 via an miR‐199a‐binding site in the 3′‐UTR. CD44+/CD117+ ovarian CICs were enriched from human primary ovarian tumor tissues and confirmed by flow cytometric sorting. miR‐199a was cloned and transfected into ovarian CICs. CD44 mRNA and protein expression was significantly decreased in miR‐199a‐transfected ovarian CICs as compared with miR‐199a mutant‐transfected and untransfected cells. Cell cycle analysis, 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐tetrazolium bromide proliferation assays, the colony formation assay and the transwell migration assay indicated that miR‐199a significantly affected cell cycle regulation and suppressed the proliferation and invasive capacity of ovarian CICs in vitro. miR‐199a significantly increased the chemosensitivity of ovarian CICs to cisplatin, pacitaxel, and adriamycin, and reduced mRNA expression of the multidrug resistance gene ABCG2 as compared with miR‐199a mutant‐transfected and untransfected cells. The expression of stemness markers was also significantly reduced in miR‐199a‐transfected CICs as compared with miR‐199a mutant‐transfected and untransfected ovarian cells. Furthermore, xenograft experiments confirmed that miR‐199a suppressed the growth of xenograft tumors formed by ovarian CICs in vivo. Thus, expression of endogenous mature miR‐199a may prevent tumorigenesis in human ovarian cancer by regulating expression of its target gene CD44.
The experiments confirmed that miR‐199a significantly affected cell cycle regulation and suppressed the proliferation and invasive capacity of ovarian CICs, and significantly increased the chemosensitivity of ovarian CICs to chemotherapeutic drugs in vitro. Furthermore, xenograft experiments confirmed that miR‐199a suppressed the growth of xenograft tumors formed by ovarian CICs in vivo. Thus, miR‐199a may prevent tumorigenesis in human ovarian cancer.
Arrhythmias originating in scarred ventricular myocardium are a major cause of death, but the underlying mechanism allowing these rhythms to exist remains unknown. This gap in knowledge critically ...limits identification of at-risk patients and treatment once arrhythmias become manifest. Here we show that potassium voltage-gated channel subfamily E regulatory subunits 3 and 4 (KCNE3, KCNE4) are uniquely upregulated at arrhythmia sites within scarred myocardium. Ventricular arrhythmias occur in areas with a distinctive cardiomyocyte repolarization pattern, where myocyte tracts with short repolarization times connect to myocytes tracts with long repolarization times. We found this unique pattern of repolarization heterogeneity only in ventricular arrhythmia circuits. In contrast, conduction abnormalities were ubiquitous within scar. These repolarization heterogeneities are consistent with known functional effects of KCNE3 and KCNE4 on the slow delayed-rectifier potassium current. We observed repolarization heterogeneity using conventional cardiac electrophysiologic techniques that could potentially translate to identification of at-risk patients. The neutralization of the repolarization heterogeneities could represent a potential strategy for the elimination of ventricular arrhythmia circuits.
Previous studies have revealed the critical roles of N6-methyladenosine (m6A) modification of mRNA in embryonic stem cells (ESCs), but the biological function of m6A in large intergenic noncoding RNA ...(lincRNA) is unknown. Here, we showed that the internal m6A modification of linc1281 mediates a competing endogenous RNA (ceRNA) model to regulate mouse ESC (mESC) differentiation. We demonstrated that loss of linc1281 compromises mESC differentiation and that m6A is highly enriched within linc1281 transcripts. Linc1281 with RRACU m6A sequence motifs, but not an m6A-deficient mutant, restored the phenotype in linc1281-depleted mESCs. Mechanistic analyses revealed that linc1281 ensures mESC identity by sequestering pluripotency-related let-7 family microRNAs (miRNAs), and this RNA-RNA interaction is m6A dependent. Collectively, these findings elucidated the functional roles of linc1281 and its m6A modification in mESCs and identified a novel RNA regulatory mechanism, providing a basis for further exploration of broad RNA epigenetic regulatory patterns.
Immune checkpoint blockade of the inhibitory immune receptors PD-L1, PD-1 and CTLA-4 has emerged as a successful treatment strategy for several advanced cancers. Here we demonstrate that miR-424(322) ...regulates the PD-L1/PD-1 and CD80/CTLA-4 pathways in chemoresistant ovarian cancer. miR-424(322) is inversely correlated with PD-L1, PD-1, CD80 and CTLA-4 expression. High levels of miR-424(322) in the tumours are positively correlated with the progression-free survival of ovarian cancer patients. Mechanistic investigations demonstrated that miR-424(322) inhibited PD-L1 and CD80 expression through direct binding to the 3'-untranslated region. Restoration of miR-424(322) expression reverses chemoresistance, which is accompanied by blockage of the PD-L1 immune checkpoint. The synergistic effect of chemotherapy and immunotherapy is associated with the proliferation of functional cytotoxic CD8+ T cells and the inhibition of myeloid-derived suppressive cells and regulatory T cells. Collectively, our data suggest a biological and functional interaction between PD-L1 and chemoresistance through the microRNA regulatory cascade.
Fast opening and closing of voltage-gated sodium channels are crucial for proper propagation of the action potential through excitable tissues. Unlike potassium channels, sodium channel α-subunits ...are believed to form functional monomers. Yet, an increasing body of literature shows inconsistency with the traditional idea of a single α-subunit functioning as a monomer. Here we demonstrate that sodium channel α-subunits not only physically interact with each other but they actually assemble, function and gate as a dimer. We identify the region involved in the dimerization and demonstrate that 14-3-3 protein mediates the coupled gating. Importantly we show conservation of this mechanism among mammalian sodium channels. Our study not only shifts conventional paradigms in regard to sodium channel assembly, structure, and function but importantly this discovery of the mechanism involved in channel dimerization and biophysical coupling could open the door to new approaches and targets to treat and/or prevent sodium channelopathies.
Computational modeling indicates that cardiac conduction may involve ephaptic coupling - intercellular communication involving electrochemical signaling across narrow extracellular clefts between ...cardiomyocytes. We hypothesized that β1(SCN1B) -mediated adhesion scaffolds
-activating Na
1.5 (SCN5A) channels within narrow (<30 nm) perinexal clefts adjacent to gap junctions (GJs), facilitating ephaptic coupling. Super-resolution imaging indicated preferential β1 localization at the perinexus, where it co-locates with Na
1.5. Smart patch clamp (SPC) indicated greater sodium current density (I
) at perinexi, relative to non-junctional sites. A novel, rationally designed peptide, βadp1, potently and selectively inhibited β1-mediated adhesion, in electric cell-substrate impedance sensing studies. βadp1 significantly widened perinexi in guinea pig ventricles, and selectively reduced perinexal I
, but not whole cell I
, in myocyte monolayers. In optical mapping studies, βadp1 precipitated arrhythmogenic conduction slowing. In summary, β1-mediated adhesion at the perinexus facilitates action potential propagation between cardiomyocytes, and may represent a novel target for anti-arrhythmic therapies.
Objectives The aim of this study was to evaluate the links between connexin43 (Cx43) expression, myocardial conduction velocity, and ventricular tachycardia in a model of healed myocardial ...infarction. Background Post-infarction ventricular arrhythmias frequently cause sudden death. Impaired myocardial conduction has previously been linked to ventricular arrhythmias. Altered connexin expression is a potential source of conduction slowing identified in healed scar border tissues. The functional effect of increasing border-zone Cx43 has not been previously evaluated. Methods Twenty-five Yorkshire pigs underwent anterior infarction by transient left anterior descending coronary artery occlusion, followed by weekly testing for arrhythmia inducibility. Twenty animals with reproducibly inducible sustained monomorphic ventricular tachycardia were randomized 2:1:1 to receive AdCx43, Adβgal, or no gene transfer. One week later, animals underwent follow-up electrophysiologic study and tissue assessment for several functional and molecular measures. Results Animals receiving AdCx43 had less electrogram fractionation and faster conduction velocity in the anterior-septal border zone. Only 40% of AdCx43 animals remained inducible for ventricular tachycardia, while 100% of controls were inducible after gene transfer. AdCx43 animals had 2-fold higher Cx43 protein levels in the anterior-septal infarct border, with similar percents of phosphorylated and intercalated disk-localized Cx43 compared with controls. Conclusions These data mechanistically link Cx43 expression to slow conduction and arrhythmia susceptibility in the healed scar border zone. Targeted manipulation of Cx43 levels improved conduction velocity and reduced ventricular tachycardia susceptibility. Cx43 gene transfer represents a novel treatment strategy for post-infarction arrhythmias.
Directly modulating the choice between homologous recombination (HR) and non-homologous end joining (NHEJ) - two independent pathways for repairing DNA double-strand breaks (DSBs) - has the potential ...to improve the efficiency of gene targeting by CRISPR/Cas9. Here, we have developed a rapid and easy-to-score screening approach for identifying small molecules that affect the choice between the two DSB repair pathways. Using this tool, we identified a small molecule, farrerol, that promotes HR but does not affect NHEJ. Further mechanistic studies indicate that farrerol functions through stimulating the recruitment of RAD51 to DSB sites. Importantly, we demonstrated that farrerol effectively promotes precise targeted integration in human cells, mouse cells and mouse embryos at multiple genomic loci. In addition, treating cells with farrerol did not have any obvious negative effect on genomic stability. Moreover, farrerol significantly improved the knock-in efficiency in blastocysts, and the subsequently generated knock-in mice retained the capacity for germline transmission.
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