Crocin alleviates neurotoxicity induced by bupivacaine in SH-SY5Y cells with inhibition of PI3K/AKT signaling.

BACKGROUND: Bupivacaine, a common local anesthetic, can cause neurotoxicity and permanent neurological disorders. Crocin has been widely reported as a potential neuroprotective agent in neural injury models. OBJECTIVE: The aim of this study was to investigate the role and regulatory mechanism of crocin underlying bupivacaine-induced neurotoxicity. METHOD: Human neuroblastoma SH-SY5Y cells were treated with bupivacaine and/or crocin for 24 h, followed by detecting cell viability using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay. The effect of crocin or bupivacaine on SH-SY5Y cell proliferation was measured by Ki67 immunofluorescence assay. The levels of apoptosis-related proteins and the markers in the PI3K/Akt signaling pathway were examined using western blot analysis. The activities of caspase 3, catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were tested using respective commercial assay kits. Flow cytometry analysis was executed for detecting SH-SY5Y cell apoptosis. RESULT: Crocin attenuated bupivacaine-induced neurotoxicity in SH-SY5Y cells. Meanwhile, crocin inhibited SH-SY5Y cell apoptosis induced by bupivacaine via repressing the activity of caspase-3, reducing Bax expression, and elevating Bcl-2 expression. Moreover, crocin mitigated oxidative stress in SH-SY5Y cells by increasing the content of CAT, SOD, GSH-Px and reducing the content of MDA. Additionally, crocin protected against bupivacaine-induced dephosphorylation of Akt and GSK-3ß. The protective effects of crocin against bupivacaine-induced neurotoxicity in SH-SY5Y cells were counteracted by the Akt inhibitor. CONCLUSION: These results suggested that crocin may exert a neuroprotective function by promoting cell proliferation and suppressing apoptosis and oxidative stress in SH-SY5Y cells. Thus, crocin might become a promising drug for the treatment of bupivacaine-induced neurotoxicity.

The impact of empirical Marshall vein ethanol infusion as a first-choice intraoperative strategy on the long-term outcomes in patients with persistent atrial fibrillation undergoing mitral isthmus ablation.

Background: Marshall vein ethanol infusion (MVEI) as an additional therapy to conventional catheter ablation (CA) has been proved to be efficacious in patients with persistent atrial fibrillation (PeAF). However, whether empirical MVEI could be the first-line strategy in mitral isthmus (MI) ablation has seldom been investigated. Here, we aim to compare the efficacy, safety, and long-term outcomes between provisional and empirical MVEI in PeAF patients undergoing the index MI ablation procedure. Methods: We enrolled 133 patients with PeAF either in the provisional group (n = 38, MVEI was performed when conventional endocardial and/or epicardial ablation procedures were inadequate to achieve bidirectional MI block) or in the empirical group (n = 95, MVEI was performed empirically before MI CA). Results: All of the baseline characteristics were comparable. Less spontaneous or inducible atrial tachycardias (ATs) were encountered in the empirical group of patients (P < 0.001). More epicardial ablations were applied (26.3% vs. 9.5%, P = 0.016) and a higher incidence of CA-facilitated restoration of sinus rhythm was recorded (86.8% vs. 11.7%, P < 0.001) in the provisional group of patients. Although more fluoroscopy time (6.4[4.2, 9.3] vs. 9.5[5.9, 11.6] min, P = 0.019) and radiation exposure (69.0[25.3, 160.2] vs. 122.0[62.5, 234.1] mGy, P = 0.010) were documented in the empirical group with comparable procedure time, less time (455.9 ± 192.2 vs. 366.5 ± 161.3 s, P = 0.038) was consumed to achieve bidirectional MI block during endocardial ablation in the provisional group. Incidences of procedure-related complications were similar between the two groups. During a 16.5 ± 4.4-month follow-up, the empirical group of patients showed a significantly higher rate of freedom from AT recurrence (95.8% vs. 81.6%, log-rank P = 0.003), while the rate of freedom from AF or atrial tachyarrhythmias (combining AF and AT) was similar. Both univariate (HR 0.19, 95% CI 0.05-0.64, P = 0.008) and multivariate (HR 0.25, 95% CI 0.07-0.92, P = 0.037) Cox regression analyses indicated that empirical MVEI was independently associated with lower long-term AT recurrence. Conclusion: Among patients with PeAF who underwent the index MI ablation procedure, empirical MVEI could reduce endocardial MI ablation time and provide greater long-term freedom from AT recurrence.

Visfatin aggravates transverse aortic constriction-induced cardiac remodelling by enhancing macrophage-mediated oxidative stress in mice.

Previous studies have reported that visfatin can regulate macrophage polarisation, which has been demonstrated to participate in cardiac remodelling. The aims of this study were to investigate whether visfatin participates in transverse aortic constriction (TAC)-induced cardiac remodelling by regulating macrophage polarisation. First, TAC surgery and angiotensin II (Ang II) infusion were used to establish a mouse cardiac remodelling model, visfatin expression was measured, and the results showed that TAC surgery or Ang II infusion increased visfatin expression in the serum and heart in mice, and phenylephrine or hydrogen peroxide promoted the release of visfatin from macrophages in vitro. All these effects were dose-dependently reduced by superoxide dismutase. Second, visfatin was administered to TAC mice to observe the effects of visfatin on cardiac remodelling. We found that visfatin increased the cross-sectional area of cardiomyocytes, aggravated cardiac fibrosis, exacerbated cardiac dysfunction, further regulated macrophage polarisation and aggravated oxidative stress in TAC mice. Finally, macrophages were depleted in TAC mice to investigate whether macrophages mediate the regulatory effect of visfatin on cardiac remodelling, and the results showed that the aggravating effects of visfatin on oxidative stress and cardiac remodelling were abrogated. Our study suggests that visfatin enhances cardiac remodelling by promoting macrophage polarisation and enhancing oxidative stress. Visfatin may be a potential target for the prevention and treatment of clinical cardiac remodelling.

CTRP5 Attenuates Doxorubicin-Induced Cardiotoxicity Via Inhibiting TLR4/NLRP3 Signaling.

BACKGROUND: C1q/tumor necrosis factor-related protein 5 (CTRP5) has been reported to be a crucial regulator in cardiac ischemia/reperfusion (I/R) injury. Nevertheless, the potential role of CTRP5 in doxorubicin (DOX)-induced cardiotoxicity and the potential mechanisms remain largely unclear. METHODS: We overexpressed CTRP5 in the hearts using an adeno-associated virus 9 (AAV9) system through tail vein injection. C57BL/6 mice were subjected to DOX (15 mg/kg/day, i.p.) to generate DOX-induced cardiotoxicity for 4 weeks. Subsequently, cardiac staining and molecular biological analysis were performed to analyze the morphological and biochemical effects of CTRP5 on the cardiac injury. H9c2 cells were used for validation in vitro. RESULTS: CTRP5 expression was down-regulated after DOX treatment both in vivo and in vitro. CTRP5 overexpression significantly attenuated DOX-induced cardiac injury, cardiac dysfunction, inhibited oxidative stress and inflammatory response. Mechanistically, CTRP5 overexpression markedly decreased the protein expression of toll-like receptor 4 (TLR4), NLRP3, cleaved caspase-1 and caspase-1, indicating TLR/NLRP3 signaling contributes to the cardioprotective role of CTRP5 in DOX-induced cardiotoxicity. CONCLUSIONS: Together, our findings demonstrated that CTRP5 overexpression could protect the heart from oxidative stress and inflammatory injury induced by DOX through inhibiting TLR4/NLRP3 signaling, suggesting that CTRP5 might be a potential therapeutic target in the prevention of DOX-induced cardiotoxicity.

Antiresistin Neutralizing Antibody Alleviates Doxorubicin-Induced Cardiac Injury in Mice.

Background: Resistin is closely related to cardiovascular diseases, and this study is aimed at examining the role of resistin in doxorubicin- (DOX-) induced cardiac injury. Methods: First, 48 mice were divided into 2 groups and treated with saline or DOX, and the expression of resistin at different time points was examined (N = 24). A total of 40 mice were pretreated with the antiresistin neutralizing antibody (nAb) or isotype IgG for 1 hour and further administered DOX or saline for 5 days. The mice were divided into 4 groups: saline-IgG, saline-nAb, DOX-IgG, and DOX-nAb (N = 10). Cardiac injury, cardiomyocyte apoptosis, inflammatory factors, and the biomarkers of M1 and M2 macrophages in each group were analyzed. Result: DOX administration increased the expression of resistin. DOX treatment exacerbated the loss of body and heart weight and cardiac vacuolation in mice. The antiresistin nAb reversed these conditions, downregulated the expression of myocardial injury markers, and decreased apoptosis. In addition, the antiresistin nAb decreased p65 pathway activation, decreased M1 macrophage differentiation and the expression of related inflammatory factors, and increased M2 macrophage differentiation and the expression of related inflammatory factors. Conclusion: The antiresistin nAb protected against DOX-induced cardiac injury by reducing cardiac inflammation and may be a promising target to relieve DOX-related cardiac injury.

Mitochondrial derived peptide MOTS-c prevents the development of heart failure under pressure overload conditions in mice.

MOTS-c, a mitochondrial-derived peptide (MDP), has been shown to have multiple biological activities such as antioxidation, anti-inflammation, and anti-apoptosis properties. In the present study, we aimed at evaluating the therapeutic effect of MOTS-c peptide in an animal model of heart failure. The heart failure mouse model was made by transverse aortic constriction (TAC) operations. The MOTS-c peptide was administrated subcutaneously by using an osmotic pump. At the end of the animal experiment, cardiac function was evaluated by echocardiography, and heart tissues were subjected to histological and molecular analysis. In vitro cultured H9C2 cells were used to test the effects of MOTS-c overexpression on cell death in response to H2 O2 stimulation. Our study showed that MOTS-c peptide attenuated TAC-induced cardiac dysfunction and remodelling. In addition, the MOTS-c peptide reduced the inflammatory response and upregulated the antioxidant capacity, coupled with the activation of the AMPK pathway in the heart of the TAC mouse model. In in vitro cultured cardiac cells, overexpression of MOTS-c was shown to activate the AMPK pathway and protect cell apoptosis in response to H2 O2 stimulation. Taken together, our study suggested that MOTS-c peptides may have therapeutic potential in treating HF.

Gab1 Overexpression Alleviates Doxorubicin-Induced Cardiac Oxidative Stress, Inflammation, and Apoptosis Through PI3K/Akt Signaling Pathway.

ABSTRACT: Grb2-associated binding protein 1 (Gab1), an intracellular scaffolding adaptor, was involved in several cardiovascular diseases. However, the role of Gab1 in doxorubicin (DOX)-induced cardiotoxicity remains largely unknown. The present study investigated whether Gab1 protected against DOX-induced cardiotoxicity and the underlying mechanism. We overexpressed Gab1 in the hearts using an adeno-associated virus 9 system through tail vein injection. C57BL/6 mice were subjected to DOX (15 mg/kg/d, i.p.) to generate DOX-induced cardiotoxicity. Echocardiography, histological analysis, immunofluorescence and enzyme-linked immunosorbent assay (ELISA) kits, Western blotting, and quantitative real-time polymerase chain reaction (PCR) evaluated DOX-induced cardiotoxicity and the underlying mechanisms. Myocardial Gab1 protein and messenger RNA (mRNA) levels were markedly decreased in DOX-administered mice. Overexpression of Gab1 in myocardium significantly improved cardiac function and attenuated cardiac oxidative stress, inflammatory response, and apoptosis induced by DOX. Mechanistically, we found that PI3K/Akt signaling pathway was downregulated after DOX treatment, and Gab1 overexpression activated PI3K/Akt signaling pathway, whereas PI3K/Akt signaling pathway inhibition abolished the beneficial effect of Gab1 overexpression in the heart. Collectively, our results indicated that Gab1 is essential for cardioprotection against DOX-induced oxidative stress, inflammatory response, and apoptosis by mediating PI3K/Akt signaling pathway. And cardiac gene therapy with Gab1 provides a novel therapeutic strategy against DOX-induced cardiotoxicity.

The Mitochondrial-Derived Peptide MOTS-c Attenuates Oxidative Stress Injury and the Inflammatory Response of H9c2 Cells Through the Nrf2/ARE and NF-κB Pathways.

AIM: Oxidative stress and the inflammatory response contribute to the progression of cardiovascular disease. The present study aimed to investigate whether the mitochondrial-derived peptide MOTS-c could alleviate H2O2-induced oxidative stress and inflammatory status in H9c2 cells through activation of nuclear factor erythroid 2-related Factor 2 (Nrf2)/antioxidative response element (ARE) and inhibition of the NF-κB pathway. METHODS: Rat H9c2 cardiomyocytes were obtained, and 10, 20 or 50 µM MOTS-c was pretreated for 24 h before treatment with H2O2. Then, the cell was treated with 100 µM H2O2 for 1 h to induce oxidative stress. An inhibition model of sh-Nrf2 was constructed via a lentivirus expression system, and an activation model of NF-κB was achieved using phorbol 12-myristate-13-acetate (PMA). Cell viability was determined using a Cell Counting kit-8 assay. Relative measurement of relative protein and mRNA expression used western blotting and qRT-PCR, respectively. Intracellular reactive oxygen species (ROS) levels were detected using dichlorodihydrofluorescein diacetate, and malondialdehyde (MDA) and superoxide dismutase (SOD) levels were determined via commercial kits. The protein expression and distribution in the cells were visualized by immunofluorescence analysis. Enzyme-linked immunosorbent assay was used to detect the levels of inflammatory cytokines, including TNF-α, IL-6 and IL-1ß. RESULTS: We found that H2O2 treatment significantly decreased cell viability and the level of SOD, increased the levels of ROS and MDA, and upregulated the expression of inflammatory cytokines, including TNF-α, IL-6 and IL-1ß, in H9c2 cells. The expression levels of Nrf2, HO-1 and NQO-1 were significantly downregulated in the H2O2, while the phosphorylation of NF-κBp65 was promoted by H2O2. However, pretreatment with MOTS-c significantly reversed H2O2-induced damage in H9c2 cells. Moreover, both inhibition of the Nrf2/ARE pathway and activation of the NF-κB pathway significantly decreased the effects of MOTS-c, suggesting that MOTS-c might play a role in alleviating oxidative damage via the Nrf2/ARE and NF-κB pathways. CONCLUSIONS: Our investigation indicated that MOTS-c could protect against H2O2-induced inflammation and oxidative stress in H9c2 cells by inhibiting NF-κB and activating the Nrf2/ARE pathways.

The Akt pathway mediates the protective effects of myeloid differentiation protein 1 in pathological cardiac remodelling.

AIMS: Myeloid differentiation protein 1 (MD1) was shown to ameliorate pressure overload-induced cardiac hypertrophy and fibrosis by negatively regulating the MEK-ERK1/2 and NF-κB pathways. However, whether MD1 modulates cardiac function and whether the Akt pathway mediates the benefits of MD1 in pressure overload-induced cardiac remodelling remain unclear. METHODS AND RESULTS: Male cardiac-specific transgenic MD1 (MD1-TG) mice, MD1-knockout (KO) mice and wild-type (WT) littermates aged 8-10 weeks were subjected to sham operation and aortic banding (AB) for 4 weeks. Then, left ventricular (LV) hypertrophy, fibrosis and function of the mice were assessed. When compared with WT-AB mice, MD1-TGs showed decreased cross-sectional area (CSA) of cardiomyocytes (P < 0.001), mRNA expression of ß-myosin heavy chain (ß-MHC) (P < 0.02), ratios of heart weight/body weight and heart weight/tibia length (P < 0.04) and collagen volume fraction (P < 0.001). The LV end-diastolic diameter was reduced, and LV ejection fraction and fractional shortening were improved in MD1-TG-AB mice than in WT-AB mice (P < 0.05). In cultured H9C2 cells, adenovirus vector-mediated MD1 overexpression decreased angiotensin II-induced mRNA expression of brain natriuretic peptide (BNP) and ß-MHC and cell CSA (P < 0.002), whereas knockdown of MD1 by shRNA exhibited opposite effects (P < 0.04). Mechanistically, MD1 suppressed pathological cardiac remodelling at least partly by blocking Akt pathway. Akt inactivation by MK2206 largely offset the pro-hypertrophic effects of MD1 deficiency in angiotensin II-stimulated cardiomyocytes. CONCLUSIONS: The Akt pathway mediates the protective effects of MD1 in pressure overload-induced cardiac remodelling in mice. Targeting MD1 may provide therapeutic strategy for the treatment of pathological cardiac remodelling and heart failure.

Left atrial appendage closure with zero fluoroscopic exposure via intracardiac echocardiographic guidance.

BACKGROUND/PURPOSE: Left atrial appendage closure (LAAC) is conventionally guided by fluoroscopy and transesophageal echocardiography. We introduce an LAAC technique without fluoroscopy exposure using intracardiac echocardiography (ICE) and electroanatomic mapping system (EAMS) under local anesthesia. METHODS: Seven non-valvular atrial fibrillation patients who underwent LAAC with the LAmbre devices under the ICE and EAMS guidance were compared to 7 patients following the conventional approach by propensity score matching. ICE probe was advanced into the left atrium (LA) to guide sizing and device implantation following the orthogonal tri-axial technique (Axis-X: from left pulmonary veins [PVs] to LAA; Axis-Y: from right PV ostium to LAA; Axis-Z: from lower LA to LAA). RESULTS: The mean diameters of ostia and landing zone were 21.4 ± 3.9 mm and 20.4 ± 4.2 mm, respectively. LAmbre devices with a mean umbrella diameter of 23.7 ± 4.2 mm and cover disc diameter of 29.4 ± 3.6 mm were successfully implanted and acute complete LAA sealing without peri-device leak (PDL) were achieved in all cases. Neither fluoroscopy exposure nor contrast consumption was recorded. No procedure related complications were documented. The mean procedural time and PDLs at follow-ups were comparable to those in the conventional group. No stroke or thromboembolic events were documented. CONCLUSION: The fluoroscopy exposure could be minimized, even to zero, in the ICEguided LAAC procedures feasibly and safely using LAmbre devices. The orthogonal triaxial technique is considered efficacious and safe for the procedures.

Myeloid differentiation protein 1 protected myocardial function against high-fat stimulation induced pathological remodelling.

Myeloid differentiation 1 (MD-1) is a secreted protein that regulates the immune response of B cell through interacting with radioprotective 105 (RP105). Disrupted immune response may contribute to the development of cardiac diseases, while the roles of MD-1 remain elusive. Our studies aimed to explore the functions and molecular mechanisms of MD-1 in obesity-induced cardiomyopathy. H9C2 myocardial cells were treated with free fatty acid (FFA) containing palmitic acid and oleic acid to challenge high-fat stimulation and adenoviruses harbouring human MD-1 coding sequences or shRNA for MD-1 overexpression or knockdown in vitro. MD-1 overexpression or knockdown transgenic mice were generated to assess the effects of MD-1 on high-fat diet (HD) induced cardiomyopathy in vivo. Our results showed that MD-1 was down-regulated in H9C2 cells exposed to FFA stimulation for 48 hours and in obesity mice induced by HD for 20 weeks. Both in vivo and in vitro, silencing of MD-1 accelerated myocardial function injury induced by HD stimulation through increased cardiac hypertrophy and fibrosis, while overexpression of MD-1 alleviated the effects of HD by inhibiting the process of cardiac remodelling. Moreover, the MAPK and NF-κB pathways were overactivated in MD-1 deficient mice and H9C2 cells after high-fat treatment. Inhibition of MAPK and NF-κB pathways played a cardioprotective role against the adverse effects of MD-1 silencing on high-fat stimulation induced pathological remodelling. In conclusion, MD-1 protected myocardial function against high-fat stimulation induced cardiac pathological remodelling through negative regulation for MAPK/NF-κB signalling pathways, providing feasible strategies for obesity cardiomyopathy.

Targeted ablation of cardiac sympathetic neurons attenuates adverse postinfarction remodelling and left ventricular dysfunction.

NEW FINDINGS: What is the central question of this study? Can targeted ablation of cardiac sympathetic neurons suppress myocardial infarction-induced adverse cardiac remodelling and left ventricular dysfunction? What is the main finding and its importance? Targeted ablation of cardiac sympathetic neurons significantly alleviated sympathetic remodelling and neuroendocrine activation, attenuated cardiac hypertrophy and fibrosis and improved left ventricular function. Thus, targeted ablation of cardiac sympathetic neurons might have a beneficial effect on adverse postinfarction remodelling and left ventricular dysfunction. ABSTRACT: Sympathetic overactivation is crucial in the development and progression of adverse cardiac remodelling and dysfunction. Targeted ablation of cardiac sympathetic neurons (TACSN) is an effective approach to inhibit overactivation of the sympathetic nervous system. The aim of this study was to investigate whether TACSN could suppress myocardial infarction (MI)-induced adverse cardiac remodelling and dysfunction, thereby producing protective effects. Thirty-eight dogs were randomly assigned into the sham-operated, MI or MI-TACSN group. The TACSN was induced by injecting cholera toxin B subunit-saporin compound into the stellate ganglia 1 week after MI. Five weeks after MI surgery, echocardiographic and haemodynamic parameters of cardiac function were significantly improved in the TACSN group compared with the MI group. In addition, TACSN attenuated the extent of cardiac hypertrophy and fibrosis and suppressed the increase in the plasma concentrations of noradrenaline, nerve growth factor, atrial natriuretic peptide, brain natriuretic peptide, angiotensin II and aldosterone. Furthermore, TACSN alleviated the growth associated protein-43-positive and tyrosine hydroxylase-positive nerve densities in the infarcted border zone and restored protein expression of the ß1 -adrenergic receptor in the left ventricular myocardium. These findings indicate that TACSN might have a beneficial effect on adverse postinfarction remodelling and left ventricular dysfunction, which might be attributable, at least in part, to the attenuation of both sympathetic remodelling and the cardiac neuroendocrine system.

Targeted ablation of cardiac sympathetic neurons improves ventricular electrical remodelling in a canine model of chronic myocardial infarction.

Aims: The purpose of this study was to evaluate the cardiac electrophysiologic effects of targeted ablation of cardiac sympathetic neurons (TACSN) in a canine model of chronic myocardial infarction (MI). Methods and results: Thirty-eight anaesthetized dogs were randomly assigned into the sham-operated, MI, and MI-TACSN groups, respectively. Myocardial infarction-targeted ablation of cardiac sympathetic neuron was induced by injecting cholera toxin B subunit-saporin compound in the left stellate ganglion (LSG). Five weeks after surgery, the cardiac function, heart rate variability (HRV), ventricular electrophysiological parameters, LSG function and neural activity, serum norepinephrine (NE), nerve growth factor (NGF), and brain natriuretic peptide (BNP) levels were measured. Cardiac sympathetic innervation was determined with immunofluorescence staining of growth associated protein-43 (GAP43) and tyrosine hydroxylase (TH). Compared with MI group, TACSN significantly improved HRV, attenuated LSG function and activity, prolonged corrected QT interval, decreased Tpeak-Tend interval, prolonged ventricular effective refractory period (ERP), and action potential duration (APD), decreased the slopes of APD restitution curves, suppressed the APD alternans, increased ventricular fibrillation threshold, and reduced serum NE, NGF, and BNP levels. Moreover, the densities of GAP43 and TH-positive nerve fibres in the infarcted border zone in the MI-TACSN group were lower than those in the MI group. Conclusion: Targeted ablation of cardiac sympathetic neuron attenuates sympathetic remodelling and improves ventricular electrical remodelling in the chronic phase of MI. These data suggest that TACSN may be a novel approach to treating ventricular arrhythmias.

Forkhead box protein k1 recruits TET1 to act as a tumor suppressor and is associated with MRI detection.

OBJECTIVE: Today, more and more evidence suggests that Foxk proteins (Foxk1 and Foxk2) work as transcriptional repressors in different kinds of cancer, but whether Foxk1 has a role in mediating tumorigenesis in breast cancer, the evidence is rare. METHODS: MCF-7 cells transfected with shFoxk1 displayed a mesenchymal morphology and reduced the expression of E-cadherin, and increased the expression of N-cadherin. Transwell invasion assay and living imaging assay show that the overexpression of Foxk1 could inhibit metastasis in vitro and in vivo. Ribonucleic acid sequencing revealed that the knockdown of Foxk1 resulted in the up-regulation of different oncogenes, which was implicated in metastasis and tumor angiopoiesis. Quantitative chromatin immunoprecipitation, chromatin immunoprecipitation and Luciferase reporter assays suggested that Foxk1 could bind to the promoter of epithelial-mesenchymal transition inducer Twist and vascular endothelial growth factor, VEGF. Mass Spectrometry, co-immunoprecipitation assays and glutathione-S-transferase pull-down assay detected that Foxk1 was physically associated with Ten-eleven translocation 1, TET1, in vivo and in vitro. RESULTS: We reported that the mean expression level of Foxk1 in breast cancer was significantly lower than the adjacent noncarcinoma tissue. The higher Foxk1 expression was associated with better prognosis. Endothelial tube formation assays indicated that Foxk1 might regulate breast cancer angiogenesis through transcriptional repression of vascular endothelial growth factor. Furthermore, in vivo magnetic resonance imaging revealed the overexpression of Foxk1 could enhance the detection of the tumors. Further, a strong negative correlation was observed between Foxk1 and Twsit or between Foxk1 and vascular endothelial growth factor, and the higher Foxk1 expression is correlated with better over all survivals and better relapse-free survivals. CONCLUSIONS: Together, our data indicated the function of Foxk1 as a tumor suppressor in facilitating angiogenesis and metastasis in breast cancer.