HMGB1 knock-down promoting tumor cells viability and arrest pro-apoptotic proteins via Stat3/NFκB in HepG2 cells

Deficiency of smooth muscle cell ILF3 alleviates intimal hyperplasia via HMGB1 mRNA degradation-mediated regulation of the STAT3/DUSP16 axis

Intimal hyperplasia is a complicated pathophysiological phenomenon attributable to in-stent restenosis, and the underlying mechanism remains unclear. Interleukin enhancer-binding factor 3 (ILF3), a double-stranded RNA-binding protein involved in regulating mRNA stability, has been recently demonstrated to assume a crucial role in cardiovascular disease; nevertheless, its impact on intimal hyperplasia remains unknown. In current study, we used samples of human restenotic arteries and rodent models of intimal hyperplasia, we found that vascular smooth muscle cell (VSMC) ILF3 expression was markedly elevated in human restenotic arteries and murine ligated carotid arteries. SMC-specific ILF3 knockout mice significantly suppressed injury induced neointimal formation. In vitro, platelet-derived growth factor type BB (PDGF-BB) treatment elevated the level of VSMC ILF3 in a dose- and time-dependent manner. ILF3 silencing markedly inhibited PDGF-BB-induced phenotype switching, proliferation, and migration in VSMCs. Transcriptome sequencing and RNA immunoprecipitation sequencing depicted that ILF3 maintained its stability upon binding to the mRNA of the high-mobility group box 1 protein (HMGB1), thereby exerting an inhibitory effect on the transcription of dual specificity phosphatase 16 (DUSP16) through enhanced phosphorylation of signal transducer and activator of transcription 3 (STAT3). Therefore, the results both in vitro and in vivo indicated that the loss of ILF3 in VSMC ameliorated neointimal hyperplasia by regulating the STAT3/DUSP16 axis through the degradation of HMGB1 mRNA. Our findings revealed that vascular injury activates VSMC ILF3, which in turn promotes intima formation. Consequently, targeting specific VSMC ILF3 may present a potential therapeutic strategy for ameliorating cardiovascular restenosis.

Aucubin protects against myocardial ischemia-reperfusion injury by regulating STAT3/NF-κB/HMGB-1 pathway

The main characteristics of the myocardial ischemia/reperfusion injury (MI/RI) are oxidative stress, apoptosis, and an inflammatory response. Aucubin (AU) is an iridoid glycoside that possesses various biological properties and has been discovered to demonstrate antioxidant and anti-inflammatory impacts in pathological processes, such as ischemia-reperfusion. The objective of this research was to investigate if AU treatment could mitigate myocardial inflammation and apoptosis caused by ischemia/reperfusion (I/R) in both laboratory and animal models, and to elucidate its underlying mechanism. By ligating the coronary artery on the left anterior descending side, a successful MI/RI rat model was created. Additionally, H9C2 cells were subjected to hypoxia/reoxygenation (H/R) in order to imitate the injury caused by ischemia/reperfusion (I/R). Furthermore, various concentrations of AU were administered to H9C2 cells or rats before H/R stimulation or myocardial I/R surgery, respectively. In vitro, the assessment was conducted on cardiac function, inflammatory markers, and myocardial pathology. In vivo, we examined the viability of cells, as well as factors related to apoptosis and oxidative stress. Furthermore, the presence of proteins belonging to the STAT3/NF-κB/HMGB1 signaling pathway was observed both in vivo and in vitro. AU effectively improved cardiomyocyte injury caused by H/R and myocardial injury caused by I/R. Furthermore, AU suppressed the production of reactive oxygen species and inflammatory molecules (TNF-alpha, IL-1β, and IL-6) and proteins associated with cell death (caspase-3 and Bax), while enhancing the levels of anti-inflammatory agents (IL-10) and the anti-apoptotic protein Bcl-2.AU mechanistically affected the phosphorylation of STAT3 at the Ser727 site and Tyr705 following H/R by modulating the signaling pathway involving signal transducer and activator of transcription 3 (STAT3)/nuclear factor-κB (NF-κB)/high mobility group box 1 (HMGB1), while also suppressing the nuclear translocation of NF-κB p65 and HMGB1 exonucleation. In conclusion, the use of AU treatment might offer protection against myocardial infarction and injury by reducing oxidative stress, suppressing apoptosis, and mitigating inflammation. The regulation of the STAT3/NF-κB/HMGB-1 pathway may contribute to this phenomenon by affecting STAT3 phosphorylation and controlling NF-κB and HMGB-1 translocation. Contributes to identifying possible objectives for myocardial ischemia/reperfusion damage.

Switch receptor T3/28 improves long-term persistence and antitumor efficacy of CAR-T cells

Background

Chimeric antigen receptor (CAR) T cells have been successfully used in tumor immunotherapy due to their strong antitumor responses, especially in hematological malignancies such as B cell acute lymphoid leukemia. However, on-target off-tumor toxicity and poor persistence severely limit the clinical application of CAR-T cell therapy.

Methods

T-cell immunoglobulin mucin domain molecule 3 (TIM-3) was used to develop a second-generation 41BB CD19 CAR linked with a T3/28 chimera, in which truncated extracellular TIM-3 was fused with the CD28 transmembrane and cytoplasmic domains. The efficacy of T3/28 CAR-T cells was evaluated in vitro and in vivo.

Results

We demonstrated that the switch receptor T3/28 preserved the T_CM phenotype, improved proliferative capacity, and reduced exhaustion of CAR-T cells, resulting in superior in vitro and in vivo antitumor activity in B lymphoma. Importantly, the switch receptor T3/28 substantially prolonged the persistence of CAR-T cells, and the interleukin-21/Stat3 axis probably contributed to the enhanced cytotoxicity of T3/28 CAR-T cells.

Conclusion

Overall, the T3/28 chimera significantly prolonged the persistence of CAR-T cells, and T3/28 CAR-T cells possessed potent antitumor activity in mice, shedding new light on potential improvements in adoptive T cell therapies.

EPHB4 Regulates the Proliferation and Metastasis of Oral Squamous Cell Carcinoma through the HMGB1/NF-κB Signalling Pathway

Background: Malignant proliferation and cervical lymphatic metastasis restrict the prognosis of oral squamous cell carcinoma (OSCC). Erythropoietin-producing human hepatocellular B4 (EPHB4) regulates a series of tumour functions involving tumourigenesis, cancer cell attachment and metastasis. However, the mechanism of EphB4 regulating the malignant progression of OSCC has not been fully elucidated. Methods: EPHB4 expression was analysed in 65 OSCC samples and adjacent noncancerous tissues through immunohistochemistry (IHC). siRNA and overexpression plasmids were transfected into OSCC cells to modify EPHB4 expression, and then, regulatory functions were explored in vitro and in vivo. Co-immunoprecipitation (Co-IP) and mass spectrometry were applied to detect proteins interacting with EPHB4. Subsequently, protein stability assays and NF-κB pathway inhibition assays were used to verify the regulation of EPHB4, high-mobility group box 1 (HMGB1) and nuclear factor-κB (NF-κB) activation. Results: EPHB4 was found to be highly expressed in OSCC tissues, which was related to tumour stage and lymphatic metastasis and resulted in a poor prognosis. Cellular experiments and mouse tongue xenograft models further confirmed that high EPHB4 expression promoted the proliferation and metastasis of OSCC tumours. Mechanistically, co-IP and mass spectrometry studies indicated that EPHB4 could bind to HMGB1 and maintain HMGB1 stability. Downregulation of HMGB1 inhibited the proliferation and metastasis of OSCC cells and inhibited NF-κB phosphorylation activation but did not affect EPHB4 expression. Conclusion: This study revealed the mechanism by which EPHB4 promotes the proliferation and metastasis of OSCC by activating the HMGB1-mediated NF-κB signalling pathway, which can be exploited as a novel marker or therapeutic target to control metastasis and improve the survival rate of OSCC.

PIGU promotes hepatocellular carcinoma progression through activating NF-κB pathway and increasing immune escape

Hepatocellular carcinoma (HCC) is the sixth most common malignancy and has the third highest mortality rate among all tumors. Previous studies found that phosphatidylinositol glycan anchor biosynthesis class U (PIGU) was highly expressed in hepatocellular carcinoma (HCC), while the function of PIGU in HCC remains unknown. Here, we deeply investigated this issue. The expression levels of PIGU in HCC cells were measured by Western blotting. The functions of PIGU in HCC cells were assessed in vitro, followed by assessing the nuclear factor-kappa B (NF-κB) pathway-related protein levels. The xenograft mouse models were conducted to investigate the effects of PIGU in vivo. Moreover, the effects of PIGU downregulation on natural killer (NK)-92 cell-mediated cell killing were detected. The results showed that PIGU was highly expressed in HCC cells compared with normal liver cells. Functional studies showed that PIGU promoted viability, cell cycle progression, migration, and invasion and suppressed apoptosis in HCC cells. Mechanism studies indicated that PIGU silencing blocked the NF-κB pathway and the blockade of the NF-κB pathway reversed the effects of PIGU overexpression on HCC cell function, including cell viability, migration, invasion, and apoptosis. In vivo studies further verified the effects of PIGU on HCC cell function, and demonstrated that PIGU knockdown suppressed tumorigenesis. Additionally, we proved that PIGU downregulation significantly enhanced the sensitivity of HCC cells to NK-92 cell cytolysis. Collectively, PIGU may promote HCC progression through activating the NF-κB pathway and promoting immune escape, indicating that PIGU may serve as a promising therapeutic target for HCC treatment.

OLFM4 Enhances STAT3 Activation and Promotes Tumor Progression by Inhibiting GRIM19 Expression in Human Hepatocellular Carcinoma

Olfactomedin 4 (OLFM4) induces signal transducer and activator of transcription 3 (STAT3) activation by inhibiting gene associated with retinoid‐interferon‐induced mortality 19 (GRIM19), a strong STAT3 suppressor gene; however, the mechanisms of OLFM4 for regulating GRIM19‐STAT3 cascade in hepatocellular carcinoma (HCC) remain unclear. The functions and regulations of OLFM4, GRIM19, and STAT3 activation in HCC progression were evaluated using surgical specimens collected from 111 HCC patients or 2 HCC cell lines in vitro. Moreover, the cancer stem cell–like property of OLFM4 mediated by leucine‐rich repeat‐containing G protein‐coupled receptor 5 (LGR5), known as an intestinal stem cell marker, was investigated. OLFM4 was increased in HCC compared with adjacent liver tissue. The multivariate analysis revealed that high OLFM4 expression was an independent factor for poor prognosis. OLFM4 expression was negatively correlated with GRIM19 expression and positively correlated with STAT3 activation in HCC, thereby increasing cell cycle progression. OLFM4 knockdown in HCC cells increased GRIM19 expression and inhibited STAT3 activation; however, after double knockdown of GRIM19 and OLFM4, STAT3 activation decreased by OLFM4 knockdown was increased again. OLFM4 knockdown increased cell apoptosis, inhibited cell proliferation, and suppressed cancer stem cell–like property in HCC cells. The incidence of hematogenous recurrence was higher in HCC patients with high OLFM4 expression, suggesting that anoikis resistance of HCC was enhanced by OLFM4. In clinical cases, LGR5 expression and CD133 expression was correlated with OLFM4 expression in HCC, leading to poor patient prognosis. In vitro, LGR5 enhanced cancer stem cell–like property by up‐regulating OLFM4 through the Wnt signaling pathway. Conclusion: OLFM4 is induced by the LGR5‐Wnt signaling pathway and is strongly associated with aggressive tumor progression and poor prognosis in HCC by regulating STAT3‐induced tumor cell proliferation and cancer stem cell–like property. Therefore, OLFM4 is a novel prognostic predictor and a potential therapeutic target for patients with HCC.