Cucurbitacin B targets STAT3 to induce ferroptosis in non-small cell lung cancer.

Cucurbitacin B (CuB) is a compound found in plants like Cucurbitaceae that has shown promise in fighting cancer, particularly in lung cancer. However, the specific impact of CuB on ferroptosis and how it works in lung cancer cells has not been fully understood. Our research has discovered that CuB can effectively slow down the growth of non-small cell lung cancer (NSCLC) cells. Even in small amounts, it was able to inhibit the growth of various NSCLC cell lines. This inhibitory effect was reversed when ferroptosis inhibitors DFO, Lip-1 and Fer-1 were introduced. CuB was found to increase the levels of reactive oxygen species (ROS), lipid ROS, MDA, and ferrous ions within H358 lung cancer cells, leading to a decrease in GSH, mitochondrial membrane potential (MMP) and changes in ferroptosis-related proteins in a dose-dependent manner. These findings were also confirmed in A549 lung cancer cells. In A549 cells, different concentrations of CuB induced the accumulation of intracellular lipid ROS, ferrous ions and changes in ferroptosis-related indicators in a concentration-dependent manner. Meanwhile, the cytotoxic effect induced by CuB in A549 cells was counteracted by ferroptosis inhibitors DFO and Fer-1. Through network pharmacology, we identified potential targets related to ferroptosis in NSCLC cells treated with CuB, with STAT3 targets showing high scores. Further experiments using molecular docking and cell thermal shift assay (CETSA) revealed that CuB interacts with the STAT3 protein. Western blot and immunofluorescence staining demonstrated that CuB inhibits the phosphorylation of STAT3 (P-STAT3) in H358 cells. Silencing STAT3 enhanced CuB-induced accumulation of lipid ROS and iron ions, as well as the expression of ferroptosis-related proteins. On the other hand, overexpression of STAT3 reversed the effects of CuB-induced ferroptosis. The results indicate that CuB has the capability to suppress STAT3 activation, resulting in ferroptosis, and could be a promising treatment choice for NSCLC.

ISG15 promotes tumor progression via IL6/JAK2/STAT3 signaling pathway in ccRCC.

Although renal cell carcinoma (RCC) is a prevalent type of cancer, the most common pathological subtype, clear cell renal cell carcinoma (ccRCC), still has poorly understood molecular mechanisms of progression. Moreover, interferon-stimulated gene 15 (ISG15) is associated with various types of cancer; however, its biological role in ccRCC remains unclear.This study aimed to explore the role of ISG15 in ccRCC progression.ISG15 expression was upregulated in ccRCC and associated with poor prognosis. RNA sequence analysis and subsequent experiments indicated that ISG15 modulated IL6/JAK2/STAT3 signaling to promote ccRCC proliferation, migration, and invasion. Additionally, our animal experiments confirmed that sustained ISG15 knockdown reduced tumor growth rate in nude mice and promoted cell apoptosis. ISG15 modulates the IL6/JAK2/STAT3 pathway, making it a potential therapeutic target and prognostic biomarker for ccRCC.

Equisetin protects from atherosclerosis in vivo by binding to STAT3 and inhibiting its activity.

Atherosclerosis is a chronic inflammatory vascular disease characterized by lipid metabolism disorder and lipid accumulation. Equisetin (EQST) is a hemiterpene compound isolated from fungus of marine sponge origin, which has antibacterial, anti-inflammatory, lipid-lowering, and weight loss effects. Whether EQST has anti-atherosclerotic activity has not been reported. In this study, we revealed that EQST displayed anti- atherosclerosis effects through inhibiting macrophage inflammatory response, lipid uptake and foam cell formation in vitro, and finally ameliorated high-fat diet (HFD)-induced atherosclerosis in AopE-/- mice in vivo. Mechanistically, EQST directly bound to STAT3 with high-affinity by forming hydrophobic bonds at GLN247 and GLN326 residues, as well as hydrogen bonds at ARG325 and THR346 residues. EQST interacted with STAT3 physically, and functionally inhibited the transcription activity of STAT3, thereby regulating atherosclerosis. Therefore, these results supports EQST as a candidate for developing anti-atherosclerosis therapeutic agent.

DDR2/STAT3 positive feedback loop mediates the immunosuppressive microenvironment by upregulating PD-L1 and recruiting MDSCs in oxaliplatin-resistant HCC.

BACKGROUND & AIMS: Transcriptome sequencing revealed high expression of discoidin domain receptor 2 (DDR2) in oxaliplatin-resistant hepatocellular carcinoma (HCC). This study aimed to explore the role of DDR2 in oxaliplatin resistance and immune evasion in HCC. METHODS: Oxaliplatin-resistant HCC cell lines were established. The interaction between DDR2 and STAT3 was investigated, along with the mechanisms involved in DDR2/STAT3-mediated PD-L1 upregulation and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) accumulation both in vitro and in vivo. RESULTS: DDR2 was found to induce the phosphorylation of STAT3, leading to its nuclear translocation. Conversely, the activation of STAT3 enhanced DDR2 expression. A positive feedback loop involving DDR2/STAT3 was identified in oxaliplatin-resistant HCC, associated with PD-L1 upregulation and PMN-MDSCs accumulation was identified in oxaliplatin-resistant HCC. Knockdown of DDR2 and STAT3 sensitized oxaliplatin-resistant HCC cells to oxaliplatin and resulted in decreased PMN-MDSCs and increased CD8+ T cells in the tumor microenvironment. ELISA array and MDSC transwell migration assays indicated that oxaliplatin-resistant HCC cells recruited PMN-MDSCs through CCL20. Dual luciferase reporter assays demonstrated that STAT3 can directly enhance the transcription of PD-L1 and CCL20. Furthermore, treatment with a PD-L1 antibody in combination with CCL20 blockade had significant antitumor effects on oxaliplatin-resistant HCC. CONCLUSIONS: Our findings revealed a positive feedback mechanism involving DDR2 and STAT3 that mediates the immunosuppressive microenvironment and promotes oxaliplatin resistance and immune evasion via PD-L1 upregulation and PMN-MDSCs recruitment. Targeting the DDR2/STAT3 pathway may be a promising therapeutic strategy to overcome immune escape and chemoresistance in HCC.

Chlorogenic acid alleviates renal fibrosis by reducing lipid accumulation in diabetic kidney disease through suppressing the Notch1 and Stat3 signaling pathway.

AIMS: Abnormal renal lipid metabolism causes renal lipid deposition, which leads to the development of renal fibrosis in diabetic kidney disease (DKD). The aim of this study was to investigate the effect and mechanism of chlorogenic acid (CA) on reducing renal lipid accumulation and improving DKD renal fibrosis. METHODS: This study evaluated the effects of CA on renal fibrosis, lipid deposition and lipid metabolism by constructing in vitro and in vivo models of DKD, and detected the improvement of Notch1 and Stat3 signaling pathways. Molecular docking was used to predict the binding between CA and the extracellular domain NRR1 of Notch1 protein. RESULTS: In vitro studies have shown that CA decreased the expression of Fibronectin, α-smooth muscle actin (α-SMA), p-smad3/smad3, alleviated lipid deposition, promoted the expression of carnitine palmitoyl transferase 1 A (CPT1A), and inhibited the expression of cholesterol regulatory element binding protein 1c (SREBP1c). The expression of Notch1, Cleaved Notch1, Hes1, and p-stat3/stat3 were inhibited. These results suggested that CA might reduce intercellular lipid deposition in human kidney cells (HK2) by inhibiting Notch1 and stat3 signaling pathways, thereby improving fibrosis. Further, in vivo studies demonstrated that CA improved renal fibrosis and renal lipid deposition in DKD mice by inhibiting Notch1 and stat3 signaling pathways. Finally, molecular docking experiments showed that the binding energy of CA and NRR1 was -6.6 kcal/mol, which preliminarily predicted the possible action of CA on Notch1 extracellular domain NRR1. CONCLUSION: CA reduces renal lipid accumulation and improves DKD renal fibrosis by inhibiting Notch1 and stat3 signaling pathways.

Inhibition of Th17 cell differentiation by aerobic exercise improves vasodilatation in diabetic mice.

BACKGROUND: Aortic endothelial diastolic dysfunction is an early complication of diabetes and the abnormal differentiation of Th17 cells is involved in the development of diabetes. However, the exact role of exercise on regulating the Th17 cells differentiation and the underlying molecular mechanisms remain to be elucidated in diabetic mice. METHODS: db/db and db/m+ mice were randomly divided into exercise and sedentary groups. Mice in exercise group were exercised daily, 6 days/week, for 6 weeks and mice in sedentary groups were placed on a nonmoving treadmill for 6 weeks. Vascular endothelial function was measured via wire myograph and the frequencies of Th17 from peripheral blood in mice were assessed via flow cytometry. RESULTS: Our data showed that exercise improved insulin resistance and aortic endothelial diastolic function in db/db mice. In addition, the proportion of Th17 cells and IL-17A level in peripheral blood of db/db mice were significantly increased, and exercise could promote Th17 cell differentiation and reduce IL-17A level. More importantly, STAT3 or ROR-γt inhibitors could promote Th17 cell differentiation in db/db mice, while exercise significantly down-regulated p-STAT3/ROR-γt signaling in db/db mice, suggesting that exercise regulated Th17 differentiation through STAT3/ROR-γt signaling. CONCLUSIONS: This study demonstrated that exercise improved vascular endothelial function in diabetic mice via reducing Th17 cell differentiation through p-STAT3/ROR-γt pathway, suggesting exercise may be an important non-pharmacological intervention strategy for the treatment of diabetes-related vascular complications.

Interleukin-5 alleviates cardiac remodelling via the STAT3 pathway in angiotensin II-infused mice.

Interleukin-5 (IL-5) has been reported to be involved in cardiovascular diseases, such as atherosclerosis and cardiac injury. This study aimed to investigate the effects of IL-5 on cardiac remodelling. Mice were infused with angiotensin II (Ang II), and the expression and source of cardiac IL-5 were analysed. The results showed that cardiac IL-5 expression was time- and dose-dependently decreased after Ang II infusion, and was mainly derived from cardiac macrophages. Additionally, IL-5-knockout (IL-5-/-) mice were used to observe the effects of IL-5 knockout on Ang II-induced cardiac remodelling. We found knockout of IL-5 significantly increased the expression of cardiac hypertrophy markers, elevated myocardial cell cross-sectional areas and worsened cardiac dysfunction in Ang II-infused mice. IL-5 deletion also promoted M2 macrophage differentiation and exacerbated cardiac fibrosis. Furthermore, the effects of IL-5 deletion on cardiac remodelling was detected after the STAT3 pathway was inhibited by S31-201. The effects of IL-5 on cardiac remodelling and M2 macrophage differentiation were reversed by S31-201. Finally, the effects of IL-5 on macrophage differentiation and macrophage-related cardiac hypertrophy and fibrosis were analysed in vitro. IL-5 knockout significantly increased the Ang II-induced mRNA expression of cardiac hypertrophy markers in myocardial cells that were co-cultured with macrophages, and this effect was reversed by S31-201. Similar trends in the mRNA levels of fibrosis markers were observed when cardiac fibroblasts and macrophages were co-cultured. In conclusions, IL-5 deficiency promote the differentiation of M2 macrophages by activating the STAT3 pathway, thereby exacerbating cardiac remodelling in Ang II-infused mice. IL-5 may be a potential target for the clinical prevention of cardiac remodelling.

Treatment of HNSC and pulmonary metastasis using the anti-helminthic drug niclosamide to modulate Stat3 signaling activity.

Background: Head and neck squamous cell carcinoma (HNSC) is a dangerous cancer that represents an important threat to human health. Niclosamide is an anti-helminthic drug that has received FDA approval. In drug repurposing screens, niclosamide was found to inhibit proliferative activity for a range of tumor types. Its functional effects in HNSC, however, have yet to be established. Methods: MTT and colony formation assays were used to explore the impact of niclosamide on the proliferation of HNSC cells, while wound healing and Transwell assays were employed to assess migration and invasivity. Flow cytometry and Western immunoblotting were respectively used to assess cellular apoptosis and protein expression patterns. An HNSC xenograft tumor model system was used to evaluate the in vivo antitumor activity of niclosamide, and immunofluorescent staining was employed to assess cleaved Caspase3 and Ki67 expression. The ability of niclosamide to prevent metastatic progression in vivo was assessed with a model of pulmonary metastasis. Results: These analyses revealed the ability of niclosamide to suppress HNSC cell migration, proliferation, and invasivity in vitro while promoting apoptotic death. From a mechanistic perspective, this drug suppressed Stat3 phosphorylation and ß-catenin expression, while increasing cleaved Caspase3 levels in HNSC cells and reducing Bcl-2 levels. Importantly, this drug was able to suppress in vivo tumor growth and pulmonary metastasis formation, with immunofluorescent staining confirming that it reduced Ki67 levels and increased cleaved Caspase3 content. Conclusion: In conclusion, these analyses highlight the ability of niclosamide to inhibit HNSC cell migration and proliferative activity while provoking apoptotic death mediated via p-Stat3 and ß-catenin pathway inactivation. Niclosamide thus holds promise for repurposing as a candidate drug for the more effective clinical management of HNSC.

Tanreqing injection inhibits stemness and enhances sensitivity of non-small cell lung cancer models to gefitinib through ROS/STAT3 signaling pathway.

Resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has emerged as a significant obstacle in managing patients with EGFR-mutant non-small-cell lung cancer (NSCLC), necessitating the exploration of novel therapeutic approaches. Tanreqing injection (TRQ) is a kind of Chinese patent medicine known for its heat-clearing and detoxifying properties. Studies have shown a correlation between tumor drug resistance and enrichment of cancer stem cells (CSCs). We aim to investigate the feasibility of TRQ enhancing sensitivity to gefitinib by targeting CSCs and reactive oxygen species (ROS). In our study, TRQ significantly inhibited cell proliferation in gefitinib-resistant non-small-cell lung cancer (NSCLC) models including 2D cell lines, 3D cell spheres, tumor-bearing animal and organoids. Compared with the gefitinib group alone, addition of TRQ elevated ROS levels, attenuated upregulation of the protein levels of sex-determining region Y-box 2 (SOX2) and aldehyde dehydrogenase 1 family member A1 (ALDH1A1) induced by gefitinib treatment, and inhibited the phosphorylation of signal transducer and activator of transcription 3 (STAT3). Scavenging ROS could restore tumor stemness, attenuate the inhibitory effect on the phosphorylation of STAT3, and promote cell proliferation. These results suggested that TRQ could enhance sensitivity of NSCLC models to gefitinib, providing a new combined treatment strategy.

STAT3 drives the malignant progression of low-grade gliomas through modulating the expression of STAT1, FOXO1, and MYC.

Low-grade glioma (LGG) is a prevalent and lethal primary brain malignancy, with most patients succumbing to recurrence and progression. The signal transducer and activator of transcription (STAT) family has long been implicated in tumor initiation and progression. However, a comprehensive evaluation of the expression status and overall function of STAT genes in LGG remains largely unreported. In this study, we investigated the association between the expression of STAT family genes and the progression of LGG. Through a comprehensive analysis that combined bioinformatics screening and validation assays, we determined that STAT1, STAT3, and STAT5A were upregulated and contributed to the malignant progression of LGG. Notably, our findings suggest that STAT3 is a critical prognostic marker that regulates the progression of LGG. STAT3 emerged as the most significant prognostic indicator governing the advancement of LGG. Additionally, our inquiry into the STAT3-binding proteins and differentially expressed-correlated genes (DEGs) revealed that STAT3 played a pivotal role in the progression of LGG by stimulating the expression of STAT1, FOXO1, and MYC. In summary, our recent study conducted a thorough analysis of the STAT family genes and revealed that directing therapeutic interventions towards STAT3 holds potential as a viable strategy for treating patients with LGG.

Britannin suppresses MCF-7 breast cancer cell growth by inducing apoptosis and inhibiting autophagy.

Objective: Breast cancer is the main reason for cancer-related death in women. Britannin is a sesquiterpene lactone compound derived from Inula aucheriana with anti-tumor properties. We aimed to explore the impacts of britannin on apoptosis and autophagy in MCF-7 breast cancer cell line. Materials and Methods: The cytotoxic influences of britannin on MCF-7 cells were estimated by the MTT method. The expression levels of apoptosis-associated genes such as CASP3, BCL2, BCL2L1, STAT3, and JAK2 and transcripts of autophagy markers including ATG1, ATG4, ATG5, ATG7, ATG12, BECN1, and MAP1LC3A were quantified using quantitative real time-PCR (qRT-PCR). Western blotting method was used to evaluate the amount of caspase 3, phosphorylated JAK2, phosphorylated STAT3, ATG1, ATG4, ATG5, Beclin1, and LC-III. Results: Treatment of MCF-7 cells with various concentrations of britannin remarkably hindered the viability of these cells compared to the controls. This compound significantly elevated the expression of pro-apoptotic caspase-3 but did not influence the levels of anti-apoptotic BCL2 and BCL2L1. Britannin decreased the levels of phosphorylated forms of JAK2 and STAT3 proteins causing the blockage of the JAK/STAT pathway. Four autophagy factors expressions, including ATG4, ATG5, Beclin1, and LCIII, were reduced due to the effect of britannin on MCF-7 cells. Conclusion: Britannin triggered apoptosis in MCF-7 cells by a mechanism that led to the blockade of the JAK/STAT pathway. Moreover, britannin prohibited autophagy in these cancer cells. This may suggest britannin as an agent for the suppression of breast tumors or as an adjutant for the enhancement of anti-breast cancer drugs effect.

Deleterious Anti-Inflammatory Macrophage Recruitment in Early Post-Infarction Phase: Unraveling the IL-6/MCP-1/STAT3 Axis.

Using a translational approach with an ST-segment myocardial infarction (STEMI) cohort and mouse model of myocardial infarction, we highlighted the role of the secreted IL-6 and MCP-1 cytokines and the STAT3 pathway in heart macrophage recruitment and activation. Cardiac myocytes secrete IL-6 and MCP-1 in response to hypoxic stress, leading to a recruitment and/or polarization of anti-inflammatory macrophages via the STAT3 pathway. In our preclinical model of myocardial infarction, neutralization of IL-6 and MCP-1 or STAT3 pathway reduced infarct size. Together, our data demonstrate that anti-inflammatory macrophages can be deleterious in the acute phase of STEMI.

E3 ubiquitin ligase RNF128 attenuates colitis and colorectal tumorigenesis by triggering the degradation of IL-6 receptors.

INTRODUCTION: Intestinal immune dysregulation is strongly linked to the occurrence and formation of tumors. RING finger protein 128 (RNF128) has been identified to play distinct immunoregulatory functions in innate and adaptive systems. However, the physiological roles of RNF128 in intestinal inflammatory conditions such as colitis and colorectal cancer (CRC) remain controversial. OBJECTIVES: To elucidate the function and mechanism of RNF128 in colitis and CRC. METHODS: Animal models of dextran sodium sulfate (DSS)-induced colitis and azoxymethane (AOM)/DSS-induced CRC were established in WT and Rnf128-deficient mice and evaluated by histopathology. Co-immunoprecipitation and ubiquitination analyses were employed to investigate the role of RNF128 in IL-6-STAT3 signaling. RESULTS: RNF128 was significantly downregulated in clinical CRC tissues compared with paired peritumoral tissues. Rnf128-deficient mice were hypersusceptible to both colitis induced by DSS and CRC induced by AOM/DSS or APC mutation. Loss of RNF128 promoted the proliferation of CRC cells and STAT3 activation during the early transformative stage of carcinogenesis in vivo and in vitro when stimulated by IL-6. Mechanistically, RNF128 interacted with the IL-6 receptor α subunit (IL-6Rα) and membrane glycoprotein gp130 and mediated their lysosomal degradation in ligase activity-dependent manner. Through a series of point mutations in the IL-6 receptor, we identified that RNF128 promoted K48-linked polyubiquitination of IL-6Rα at K398/K401 and gp130 at K718/K816/K866. Additionally, blocking STAT3 activation effectively eradicated the inflammatory damage of Rnf128-deficient mice during the transformative stage of carcinogenesis. CONCLUSION: RNF128 attenuates colitis and colorectal tumorigenesis by inhibiting IL-6-STAT3 signaling, which sheds novel insights into the modulation of IL-6 receptors and the inflammation-to-cancer transition.

Glycyrrhetinic acid triggers a protective autophagy by inhibiting the JAK2/STAT3 pathway in cerebral ischemia/reperfusion injury.

Cerebral ischemia/reperfusion injury (CIRI) is a common feature of ischemic stroke leading to a poor prognosis. Effective treatments targeting I/R injury are still insufficient. The study aimed to investigate the mechanisms, by which glycyrrhizic acid (18ß-GA) in ameliorates CIRI. Our results showed that 18ß-GA significantly decreased the infarct volume, neurological deficit scores, and pathological changes in the brain tissue of rats after middle cerebral artery occlusion. Western blotting showed that 18ß-GA inhibited the expression levels of phosphorylated JAK2 and phosphorylated STAT3. Meanwhile, 18ß-GA increased LC3-II protein levels in a reperfusion duration-dependent manner, which was accompanied by an increase in the Bcl-2/Bax ratio. Inhibition of 18ß-GA-induced autophagy by 3-methyladenine (3-MA) enhanced apoptotic cell death. In addition, 18ß-GA inhibited the JAK2/STAT3 pathway, which was largely activated in response to oxygen-glucose deprivation/reoxygenation. However, the JAK2/STAT3 activator colivelin TFA abolished the inhibitory effect of 18ß-GA, suppressed autophagy, and significantly decreased the Bcl-2/Bax ratio. Taken together, these findings suggested that 18ß-GA pretreatment ameliorated CIRI partly by triggering a protective autophagy via the JAK2/STAT3 pathway. Therefore might be a potential drug candidate for treating ischemic stroke.

Ursolic acid improves necroptosis via STAT3 signaling in intestinal ischemia/reperfusion injury.

Intestinal ischemia/reperfusion injury (IRI) poses a serious threat to human survival and quality of life with high mortality and morbidity rates. The current absence of effective treatments for intestinal IRI highlights the urgent need to identify new therapeutic targets. Ursolic acid (UA), a pentacyclic triterpene natural compound, has been shown to possess various pharmacological properties including intestinal protection. However, its potential protective efficacy on intestinal IRI remains elusive. This study aimed to investigate the effect of UA on intestinal IRI and explore the underlying mechanisms. To achieve this, we utilized network pharmacology to analyze the mechanism of UA in intestinal IRI and assessed UA's effects on intestinal IRI using a mouse model of superior mesenteric artery occlusion/reperfusion and an in vitro model of oxygen-glucose deprivation and reperfusion-induced IEC-6 cells. Our results demonstrated that UA improved necroptosis through the RIP1/RIP3/MLKL pathway, reduced necroinflammation via the HMGB1/TLR4/NF-κB pathway, attenuated morphological damage, and enhanced intestinal barrier function. Furthermore, UA pretreatment downregulated the phosphorylation level of signal transducer and activator of transcription 3 (STAT3). The effects of UA were attenuated by the STAT3 agonist Colivelin. In conclusion, our study suggests that UA can improve intestinal IRI by inhibiting necroptosis in enterocytes via the suppression of STAT3 activation. These results provide a theoretical basis for UA treatment of intestinal IRI and related clinical diseases.

α7nAChR-mediated astrocytic activation: a novel mechanism of Xiongzhi Dilong decoction in ameliorating chronic migraine.

ETHNOPHARMACOLOGICAL RELEVANCE: Alpha 7 nicotinic acetylcholine receptor (α7nAChR)-mediated astrocytic activation is closely related to central sensitization of chronic migraine (CM). Xiongzhi Dilong decoction (XZDL), originated from Xiongzhi Shigao decoction of Yi-zong-jin-jian, has been confirmed to relieve CM in experiment and clinic. However, its underlying mechanism for treating CM has not been elucidated. AIM OF THE STUDY: To reveal the underlying mechanisms of XZDL to alleviate CM in vivo focusing mainly on α7nAChR-mediated astrocytic activation and central sensitization in TNC. MATERIALS AND METHODS: CM rat model was established by subcutaneous injection of nitroglycerin (NTG) recurrently, and treated with XZDL simultaneously. Migraine-like behaviors of rats (ear redness, head scratching, and cage climbing) and pain-related reactions (mechanical hind-paw withdrawal threshold) of rats were evaluated before and after NTG injection and XZDL administration at different points in time for nine days. The immunofluorescence single and double staining were applied to detect the levels of CGRP, c-Fos, GFAP and α7nAChR in NTG-induced CM rats. ELISA kits were employed to quantify levels of TNF-α, IL-1ß, and IL-6 in medulla oblongata of CM rats. The expression levels of target proteins were examined using western blotting. Finally, methyllycaconitine citrate (MLA, a specific antagonist of α7nAChR) was applied to further validate the mechanisms of XZDL in vivo. RESULTS: XZDL significantly attenuated the pain-related behaviors of the NTG-induced CM rats, manifesting as constraints of aberrant migraine-like behaviors including elongated latency of ear redness and decreased numbers of head scratching and cage climbing, and increment of mechanical withdrawal threshold. Moreover, XZDL markedly lowered levels of CGRP and c-Fos, as well as inflammatory cytokines (IL-1ß, IL-6 and TNF-α) in CM rats. Furthermore, XZDL significantly enhanced α7nAChR expression and its co-localization with GFAP, while markedly inhibited the expression of GFAP and the activation of JAK2/STAT3/NF-κB pathway in the TNC of CM rats. Finally, blocking α7nAChR with MLA reversed the effects of XZDL on astrocytic activation, central sensitization, and the pain-related behaviors in vivo. CONCLUSION: XZDL inhibited astrocytic activation and central sensitization in NTG-induced CM rats by facilitating α7nAChR expression and suppressing JAK2/STAT3/NF-κB pathway, implying that the regulation of α7nAChR-mediated astrocytic activation represents a novel mechanism of XZDL for relieving CM.

MicroRNA-513b-5p inhibits epithelial mesenchymal transition of colon cancer stem cells through IL-6/STAT3 signaling pathway.

OBJECTIVE: To reveal the mechanisms by which miR-513b-5p inhibits metastasis of colon cancer stem cells (CCSCs) through IL-6/STAT3 in HCT116 cells. METHODS: Sphere formation media and magnetic cell sorting were used to enrich and screen CCSCs. We used a colony formation assay, cell proliferation and viability assays, and a nude mouse transplantation tumor assay to identify CCSCs. ELISA was performed to identify IL-6 in the cell culture medium, and the growth, viability, wound healing, and transwell migration of distinct cell groups were compared to differentiate them. Dual-luciferase reporter assay, RT-PCR, and/or Western Blot analysis were conducted to determine the correlation between them. RESULTS: CD133+CD44+ HCT116 cells were shown to have higher cloning efficiency, greater proliferation ability and viability, and stronger tumorigenicity. A dual-luciferase reporter assay revealed that miR-513b-5p negatively affected STAT3 expression. RT-PCR and/or Western Blot analysis suggested that miR-513b-5p negatively affected STAT3 and Vimentin, while positively affecting E-cadherin expression. The STAT3 overexpression vector + miR-513b-5p inhibitor cell group had the highest efficiency, greatest proliferation ability and viability, and the highest IL-6 level in the experiments. CONCLUSIONS: Mir-513b-5p inhibited the epithelial-mesenchymal transition (EMT) of CCSCs through IL-6/STAT3. This potential mechanism may provide a new therapeutic target for colon cancer.

Tumor cell-intrinsic MELK enhanced CCL2-dependent immunosuppression to exacerbate hepatocarcinogenesis and confer resistance of HCC to radiotherapy.

BACKGROUND: The outcome of hepatocellular carcinoma (HCC) is limited by its complex molecular characteristics and changeable tumor microenvironment (TME). Here we focused on elucidating the functional consequences of Maternal embryonic leucine zipper kinase (MELK) in the tumorigenesis, progression and metastasis of HCC, and exploring the effect of MELK on immune cell regulation in the TME, meanwhile clarifying the corresponding signaling networks. METHODS: Bioinformatic analysis was used to validate the prognostic value of MELK for HCC. Murine xenograft assays and HCC lung metastasis mouse model confirmed the role of MELK in tumorigenesis and metastasis in HCC. Luciferase assays, RNA sequencing, immunopurification-mass spectrometry (IP-MS) and coimmunoprecipitation (CoIP) were applied to explore the upstream regulators, downstream essential molecules and corresponding mechanisms of MELK in HCC. RESULTS: We confirmed MELK to be a reliable prognostic factor of HCC and identified MELK as an effective candidate in facilitating the tumorigenesis, progression, and metastasis of HCC; the effects of MELK depended on the targeted regulation of the upstream factor miR-505-3p and interaction with STAT3, which induced STAT3 phosphorylation and increased the expression of its target gene CCL2 in HCC. In addition, we confirmed that tumor cell-intrinsic MELK inhibition is beneficial in stimulating M1 macrophage polarization, hindering M2 macrophage polarization and inducing CD8 + T-cell recruitment, which are dependent on the alteration of CCL2 expression. Importantly, MELK inhibition amplified RT-related immune effects, thereby synergizing with RT to exert substantial antitumor effects. OTS167, an inhibitor of MELK, was also proven to effectively impair the growth and progression of HCC and exert a superior antitumor effect in combination with radiotherapy (RT). CONCLUSIONS: Altogether, our findings highlight the functional role of MELK as a promising target in molecular therapy and in the combination of RT therapy to improve antitumor effect for HCC.

Thrombocytopenia and hyperprogression after radiotherapy and camrelizumab treatment in an esophageal cancer patient with increased JAK2 gene copies: a case report.

Radiotherapy (RT) and immune checkpoint inhibitor (ICI) are important treatments for esophageal cancer. Some studies have confirmed the safety and effectiveness of using RT in combination with ICI, while serious side effects have been exhibited by some patients. We report a patient with metastatic esophageal cancer who received RT combined with ICI. The patient experienced severe thrombocytopenia, and treatment with thrombopoietin and corticosteroids were ineffective. Finally, the patient developed abscopal hyperprogression outside the radiation field. Interestingly, next-generation sequencing revealed increased JAK2 gene copies in the surgical slices. The JAK2/STAT3 pathway is involved in the regulation of megakaryocyte development. Recurrent thrombocytopenia may activate the JAK2/STAT3 pathway, leading to megakaryocyte differentiation and platelet biogenesis. However, persistent activation of the JAK2/STAT3 pathway has been associated with immune ICI resistance and tumor progression. This case indicates that thrombocytopenia and increased JAK2 gene copies may be risk factors for poor prognosis after ICI and RT treatment.