A natural acylphloroglucinol exerts anti-erythroleukemia effects via targeting STAT3 and p38-MAPK, and inhibiting PI3K/AKT/mTOR signaling pathway.

Erythroleukemia, a subtype of acute myeloid leukemia (AML), is a life-threatening malignancy that affects the blood and bone marrow. Despite the availability of clinical treatments, the complex pathogenesis of the disease and the severe side effects of chemotherapy continue to impede therapeutic progress in leukemia. In this study, we investigated the antitumor activity of L76, an acylphloroglucinol compound derived from Callistemon salignus DC., against erythroleukemia, along with its underlying mechanisms. MTT assays were performed to evaluate the inhibitory effects of L76 on cancer cell viability, while flow cytometry was used to analyze apoptosis and cell cycle arrest in HEL cells. The molecular mechanisms of L76 were further explored using Western blotting, microscopic analysis, and cellular thermal shift assays (CETSA). Our in vitro experiments demonstrated that L76 inhibits proliferation, induces G1/S cell cycle arrest, and promotes apoptosis in human leukemia cells. Mechanistically, L76 exerts its effects by targeting STAT3 and p38-MAPK, and by inhibiting the PI3K/AKT/mTOR signaling pathway. In conclusion, this study highlights the potential of L76 as an anti-erythroleukemia agent, demonstrating its ability to target STAT3 and p38-MAPK, and to inhibit the PI3K/AKT/mTOR signaling pathway. These findings suggest that L76 could be a promising candidate for the treatment of erythroleukemia.

Brown adipose tissue-derived exosomes improve polycystic ovary syndrome in mice via STAT3/GPX4 signaling pathway.

Polycystic ovary syndrome (PCOS) is associated with impaired adipose tissue physiology. Elevated brown adipose tissue (BAT) mass or activity has shown potential in the treatment of PCOS. In this study, we aimed to investigate whether BAT-derived exosomes (BAT-Exos), as potential biomarkers of BAT activity, exert similar benefits as BAT in the treatment of PCOS. PCOS was induced in female C57BL/6J mice orally administered 1 mg/kg of letrozole for 21 days. Subsequently, the animals underwent transplantation with BAT or administered BAT-Exos (200 µg) isolated from young healthy mice via the tail vein; healthy female mice were used as controls. The results indicate that BAT-Exos treatment significantly reduced body weight and improved insulin resistance in PCOS mice. In addition, BAT-Exos improved ovulation function by reversing the acyclicity of the estrous cycle, decreasing circulating luteinizing hormone and testosterone, recovering ovarian performance, and improving oocyte quality, leading to a higher pregnancy rate and litter size. Furthermore, western blotting revealed reduced expression of signal transducer and activator of transcription 3 (STAT3) and increased expression of glutathione peroxidase 4 (GPX4) in the ovaries of mice in the BAT-Exos group. To further explore the role of the STAT3/GPX4 signaling pathway in PCOS mice, we treated the mice with an intraperitoneal injection of 5 mg/kg stattic, a STAT3 inhibitor. Consistent with BAT-Exos treatment, the administration of stattic rescued letrozole-induced PCOS phenotypes. These findings suggest that BAT-Exos treatment might be a potential therapeutic strategy for PCOS and that the STAT3/GPX4 signaling pathway is a critical therapeutic target for PCOS.

Bacterial Extracellular Vesicles as Potential Promoting Factors for Oral Lichen Planus Pathogenesis.

Oral lichen planus (OLP) is a chronic inflammatory disease characterized by an intensive infiltration of cytotoxic T cells, which causes keratinocyte death. Abnormal changes within keratinocytes might be critical for OLP onset and progression, but the pathogenic mechanism of OLP is still uncertain. The human oral microbiota, consisting of approximately 50-100 billion bacterial entities, encompasses around 200 dominant bacterial species. These bacteria continuously produce and release extracellular vesicles (EVs), which play a significant role in host-microbe interactions. However, the impact of these bacterial EVs on the progression of OLP has not been fully elucidated. In this study, through comprehensive database analysis and experimental validation, we observed that OLP lesions exhibit elevated inflammatory signatures and significantly increased phosphorylation of STAT3 compared to non-OLP tissues. Notably, EVs derived from key periodontal pathogens, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, were shown to induce an inflammatory response and activate STAT3 signaling pathways, closely mirroring the pathophysiological features observed in OLP. These results underscore the potential role of bacterial EVs in the pathogenesis of OLP and highlight STAT3 as a critical mediator in this process.

JAK inhibitors to treat STAT3 gain-of-function: a single-center report and literature review.

Objective: The signal transducer and activator of transcription 3 (STAT3) gain-of-function (GOF) syndrome (STAT3-GOF) is an inborn error of immunity (IEI) characterized by diverse manifestations of immune dysregulation that necessitate systemic immunomodulatory treatment. The blockade of the interleukin-6 receptor and/or the inhibition of the Janus kinases has been commonly employed to treat diverse STAT3-GOF-associated manifestations. However, evidence on long-term treatment outcome, especially in the case of adult patients, is scarce. Methods: Clinical data, including laboratory findings and medical imaging, were collected from all seven patients, diagnosed with STAT3-GOF, who have been treated at the Hannover University School, focusing on those who received a Janus kinase (JAK) inhibitor (JAKi). Previously published cases of STAT3-GOF patients who received a JAKi were evaluated, focusing on reported treatment efficacy with respect to diverse STAT3-GOF-associated manifestations of immune dysregulation and safety. Results: Five out of seven patients diagnosed with STAT3-GOF were treated with a JAKi, each for a different indication. Including these patients, outcomes of JAKi treatment have been reported for a total of 41 patients. Treatment with a JAKi led to improvement of diverse autoimmune, inflammatory, or lymphoproliferative manifestations of STAT3-GOF and a therapeutic benefit could be documented for all except two patients. Considering all reported manifestations of immune dysregulation in each patient, complete remission was achieved in 10/41 (24.4%) treated patients. Conclusions: JAKi treatment improved diverse manifestations of immune dysregulation in the majority of STAT3-GOF patients, representing a promising therapeutic approach. Long-term follow-up data are needed to evaluate possible risks of prolonged treatment with a JAKi.

Induction, growth, drug resistance, and metastasis: A comprehensive summary of the relationship between STAT3 and gastric cancer.

Gastric cancer is a prevalent and highly lethal malignancy that poses substantial challenges to healthcare systems globally. Owing to its often asymptomatic nature in early stages, diagnosis frequently occurs at advanced stages when surgical intervention is no longer a viable option, forcing most patients to rely on nonsurgical treatments such as chemotherapy, targeted therapies, and emerging immunotherapies. Unfortunately, the therapeutic response rates for these treatments are suboptimal, and even among responders, the eventual development of drug resistance remains a significant clinical hurdle. Signal transducer and activator of transcription 3 (STAT3) is a widely expressed cellular protein that plays crucial roles in regulating cellular processes such as growth, metabolism, and immune function. Aberrant activation of the STAT3 pathway has been implicated in the initiation, progression, and therapeutic resistance of several cancers, with gastric cancer being particularly affected. Dysregulated STAT3 signaling not only drives tumorigenesis but also facilitates the development of resistance to chemotherapy and targeted therapies, as well as promotes metastatic dissemination. In this study, we explored the critical role of the STAT3 signaling cascade in the pathogenesis of gastric cancer, its contribution to drug resistance, and its involvement in the metastatic process. Furthermore, we assess recent advances in the development of STAT3 inhibitors and their potential application as therapeutic agents in the treatment of gastric cancer. This work provides a comprehensive overview of the current understanding of STAT3 in gastric cancer and offers a foundation for future research aimed at improving therapeutic outcomes in this challenging disease.

Neutralization of TLR2 in combination with either TNF-α or IL-1ß antibody reduces the severity of septic arthritis through STAT3/mTOR signalling in lymphocytes.

Staphylococcus aureus induced Septic arthritis is considered a medical concern. S.aureus binds TLR2 to induce an array of inflammatory responses. Generation of pro-inflammatory cytokines induces T cell responses and control Th17/Treg cell balance. Regulation of T cell-mediated immunity in response to inflammation is significantly influenced by mTOR. Presence of elevated TNF-α, IL-1ß decreases Treg cell activity through STAT3/mTOR, promoting proliferation of T cells towards Th17 cells. Therefore, we postulated, neutralizing TLR2 with either TNF-α or IL-1ß in combination could be useful in modifying Th17/Treg cell ratio in order to treat septic arthritis by suppressing expression of mTOR/STAT3. To date, no studies have reported effects of neutralization of TLR2 along with either TNF-α or IL-1ß on amelioration of arthritis correlating with mTOR/STAT3 expression. Contribution of T lymphocytes collected from blood, spleen, synovial tissues, their derived cytokines IFN-γ, IL-6, IL-17, TGF-ß, IL-10 were noted. Expression of TLR2, TNFR1, TNFR2, NF-κB along with mTOR/STAT3 also recorded. Neutralization of TLR2 along with TNF-α and IL-1ß were able to shift Th17 cells into immunosuppressive Treg cells. Furthermore,elevated expression of IL-10, TNFR2 and demoted expression of mTOR/ STAT3 along with NF-κB in lymphocytes confirms its role in resolution of arthritis. It was also effective in reducing oxidative stress via increasing expression of the antioxidant enzymes. As a result, it can be inferred that Treg-derived IL-10, which may mitigate inflammatory effects of septic arthritis by influencing the mTOR/STAT3 interaction in lymphocytes, may be selected as a different therapeutic strategy for reducing the impact of septic arthritis.

The promotion of cell proliferation and invasion in cutaneous squamous cell carcinomas after ARNT downregulation is associated with CXCL3.

The aryl hydrocarbon receptor nuclear translocator (ARNT) is a transcription factor associated with adaptive responses to cellular stress. Its role in cutaneous squamous cell carcinoma (cSCC) remains poorly understood. The aim of this study was to investigate the role of ARNT in cSCC. Immunohistochemistry revealed downregulation of ARNT in cSCC, precancerous lesions (actinic keratosis), and cells. Knockdown of ARNT in A431 and SCL-1 cells significantly enhanced cell growth and metastasis. Microarray analysis and Ingenuity Pathway Analysis confirmed that loss of ARNT in A431 cells was highly correlated with cell growth and movement and upregulated CXCL3 expression. Cellular and xenograft experiments further confirmed that ARNT regulates cSCC proliferation and invasiveness in a CXCL3-dependent manner. ARNT may regulate CXCL3 expression through ROS-STAT3 pathway. In conclusion, this study demonstrates that ARNT plays a critical role in the development of cSCC and significantly affects the proliferation and metastatic ability of cSCC cells. It has the potential to serve as an ideal treatment target for cSCC.

PLXDC1 serves as a potential prognostic marker and involves in malignant progression and macrophage polarization in colon cancer.

The malignant behavior and immune escape ability of cancer cells lead to therapeutic failure and poor prognosis for patients with various cancers, including colon cancer. Plexin domain containing 1 (PLXDC1) was initially identified to exert key roles in tumor by regulating angiogenesis and has recently proved to be involved in cell proliferation and migration of glioblastoma and gastric cancer cells. However, its roles in colon cancer remain unclear. In this study, the online bioinformatics databases confirmed high expression of PLXDC1 in colon cancer specimens, which was associated with cancer stages and nodal metastasis. Similarly, the increased expression of PLXDC1 was also validated in our collected samples and colon cancer cells. Moreover, patients with high expression of PLXDC1 had shorter survival, indicating that PLXDC1 might be a potential prognostic predictor for colon cancer patients. Notably, targeting PLXDC1 inhibited cancer cell viability and invasion, and enhanced cell apoptosis. Intriguingly, Tumor Immune Estimation Resource database confirmed that PLXDC1 expression was related to various tumor-infiltrating immune cells in colon adenocarcinoma including macrophages, and its expression was also correlated with M2-like macrophage markers. In vitro, colon cancer cells with PLXDC1 downregulation had a reduced ability to recruit and polarize macrophage towards M2 phenotype by decreasing the percentage of CD206+ cells and M2-like markers (CD206, CD163, arginase1, and interleukin 10 [IL-10]). Moreover, PLXDC1 knockdown attenuated M2 macrophage-mediated promotion in cancer cell viability and invasion. Mechanically, inhibition of PLXDC1 suppressed activation of the IL-6/Signal transducer and activator of transcription 3 (STAT3) signaling. Reactivating the above pathway by transfection with IL-6 plasmids reversed the suppressive effects of PLXDC1 knockdown on cancer cell malignant behaviors, macrophage recruitment and M2-like polarization. Thus, PLXDC1 downregulation may inhibit the malignancy of colon cancer cells and their ability to recruit and polarize macrophages towards M2 phenotype by blocking the IL-6/STAT3 pathway. Together, targeting PLXDC1 may attenuate the progression of colon cancer by direct roles in cancer cells and indirect roles in macrophage polarization, representing a promising therapeutic target for colon cancer patients.

Protein Kinase C-Delta Mediates Cell Cycle Reentry and Apoptosis Induced by Amyloid-Beta Peptide in Post-Mitotic Cortical Neurons.

Amyloid-beta peptide (Aß) is a neurotoxic constituent of senile plaques in the brains of Alzheimer's disease (AD) patients. The detailed mechanisms by which protein kinase C-delta (PKCδ) contributes to Aß toxicity is not yet entirely understood. Using fully differentiated primary rat cortical neurons, we found that inhibition of Aß25-35-induced PKCδ increased cell viability with restoration of neuronal morphology. Using cyclin D1, proliferating cell nuclear antigen (PCNA), and histone H3 phosphorylated at Ser-10 (p-Histone H3) as the respective markers for the G1-, S-, and G2/M-phases, PKCδ inhibition mitigated cell cycle reentry (CCR) and subsequent caspase-3 cleavage induced by both Aß25-35 and Aß1-42 in the post-mitotic cortical neurons. Upstream of PKCδ, signal transducers and activators of transcription (STAT)-3 mediated PKCδ induction, CCR, and caspase-3 cleavage upon Aß exposure. Downstream of PKCδ, aberrant neuronal CCR was triggered by overactivating cyclin-dependent kinase-5 (CDK5) via calpain2-dependent p35 cleavage into p25. Finally, PKCδ and CDK5 also contributed to Aß25-35 induction of p53-upregulated modulator of apoptosis (PUMA) in cortical neurons. Together, we demonstrated that, in the post-mitotic neurons exposed to Aßs, STAT3-dependent PKCδ expression triggers calpain2-mediated p35 cleavage into p25 to overactivate CDK5, thus leading to aberrant CCR, PUMA induction, caspase-3 cleavage, and ultimately apoptosis.

Tumor-derived exosome PPP3CB induce gemcitabine resistance by regulating miR-298/STAT3 in pancreatic cancer.

Purpose: Due to resistance to gemcitabine (GEM), patients with pancreatic cancer (PC) usually have poor prognosis and low survival rate. The purpose of our research was to explore the impact of exosome PPP3CB on GEM resistance in PC, and concurrently analyze the regulatory role of the miR-298/STAT3 signaling pathway. Methods: Exosomes isolated from PC cells were verified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blotting (WB). The interaction between PPP3CB and miR-298 was verified using dual-luciferase reporter gene assay, followed by evaluation of cell growth and death using CCK8 assay, EdU staining, and flow cytometry. Results: Increased PPP3CB expression was observed in GEM-resistant PC cells. Exosomes from PC cells and GEM-resistant PC cells were successfully extracted by ultra-high speed centrifugation. Confocal microscopy showed internalization of fluorescein amide (FAM)-labeled GEM-resistant exosomes by PC cells. PPP3CB enhanced the proliferation of GEM-resistant PC cells and inhibited their apoptosis, whereas down-regulation of PPP3CB promoted the death of PC cells and inhibited the proliferation of GEM-resistant PC cells, and enhance the susceptibility of PC cells to GEM. Additionally, PPP3CB positively regulated STAT3 expression in PC cells by down-regulating miR-298, thus promoting the growth and inhibiting the death of PC cells. Conclusion: PC cell-derived exosome PPP3CB enhances STAT3 expression by downregulating miR-298, stimulating cell growth, and suppressing cell death, thereby increasing the resistance of PC cells to GEM.

Alantolactone alleviates epithelial-mesenchymal transition by regulating the TGF-ß/STAT3 signaling pathway in renal fibrosis.

Objective: The epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs) plays a crucial role in renal interstitial fibrosis and inflammation, which are key components of chronic kidney disease (CKD). Alantolactone, a selective inhibitor of signal transducer and activator of transcription 3 (STAT3), is used in Chinese herbal medicine. Despite its use, the effects of alnatolactone on EMT of RTECs has not been fully elucidated. Methods: In this study, we investigated the potential of alantolactone to EMT in vivo and in vitro. Our experiments were performed using a unilateral ureteral obstruction (UUO) models and HK-2 cells, RTECs, treated with transforming growth factor (TGF-ß). Results: Alantolactone decreased tubular injury and reduced the expression of vimentin, a key EMT marker, while increasing E-cadherin expression in UUO kidneys. Similarly, in RTECs, alantolactone inhibited TGF-ß-induced EMT and its markers. Furthermore, alantolactone attenuated UUO- and TGF-ß-induced STAT3 phosphorylation both in vivo and in vitro, and inhibited the expression of TWIST, an EMT transcription factor, in both models. Conclusion: Alantolactone improves EMT in RTECs by inhibiting STAT3 phosphorylation and Twist expression, suggesting its potential as a therapeutic agent for kidney fibrosis.

The Atypical Dual Specificity Phosphatase DUSP15 Regulates Jak1-Mediated STAT3 Activation.

The signal transducer and activator of transcription 3 (STAT3) protein is a key regulator of cell differentiation, proliferation, and survival in hematopoiesis, immune responses, and other biological systems. STAT3 transcriptional activity is strictly regulated through various mechanisms, such as phosphorylation and dephosphorylation. In this study, we attempted to identify novel phosphatases which regulate STAT3 activity in response to cytokine stimulations. To this end, leukemia inhibitory factor (LIF)/STAT3 dependent phosphatase induction was evaluated in the mouse hepatoma cell line Hepa1-6. After LIF stimulation, the expression of several atypical dual specific phosphatases (aDUSPs) was upregulated in Hepa1-6 cells. Among the LIF-induced aDUSPs, we focused on DUSP15 and clarified its functions in LIF/STAT3 signaling using RNA interference. DUSP15 knockdown decreased LIF-induced Socs3 mRNA expression and STAT3 translocation. Furthermore, loss of DUSP15 reduced the phosphorylation of STAT3 at Tyr705 and Janus family tyrosine kinase 1 (Jak1) at Tyr1034/1035 in response to LIF. The interaction between Jak1 and DUSP15 was observed in LIF-stimulated Hepa1-6 cells. We also demonstrated the suppression of granulocyte colony-stimulating factor (G-CSF)-mediated gp130/STAT3-dependent cell growth of Ba/F-G133 cells via DUSP15 knockdown. Therefore, DUSP15 functions as a positive feedback regulator in the Jak1/STAT3 signaling cascade.

Modulation of esophageal squamous cell carcinoma progression: the impact of CCR7 on JAK2/STAT3 signaling pathway.

BACKGROUND: Existing studies have already revealed the involvement of C-C chemokine receptor type 7 (CCR7) in diverse human cancers, including esophageal cell squamous carcinoma (ESCA). Our current study, aims to explore the relevant mechanisms implicated. METHODS: ESCA cell lines were collected for CCR7 expression quantification using western blot. Following the transfection, the viability, migration and invasion of ESCA cells were evaluated via cell counting kit-8 and Transwell assays. The specific molecular mechanisms underlying the effects of CCR7 in ESCA cells were explored via calculating the expressions of proteins related to metastasis and Janus kinase 2/signal transduction and transcription activation 3 (JAK2/STAT3) signaling pathway via western blot. The correlation between CCR7 and metastasis-related proteins was explored via Pearson's correlation test. RESULTS: CCR7 was high-expressed in ESCA cells and CCR7 knockdown repressed the viability, migration and invasion of ESCA cells, concurrent with the increased expression of E-cadherin (E-cad, which was also known as CDH1 and lowly expressed in ESCA cells) and the decreased expressions of vimentin (Vim, which was highly expressed in ESCA cells) and matrix metalloproteinase-9 (MMP-9, which was also highly expressed in ESCA cells). Meanwhile, CCR7 was positively correlated with Vim and MMP-9 yet negatively correlated with E-cad in ESCA cells, which indicated that CCR7 has a role in promoting tumor progression in ESCA cells. Besides, the phosphorylation of STAT3 and JAK2 in ESCA cells was elevated, which was diminished following CCR7 knockdown. CONCLUSION: This study proves the modulation of CCR7 on ESCA in vitro, which was achieved via JAK2/STAT3 signaling pathway. Our discovery will provide new therapeutic basis and insights for ESCA.

A TCM formula assists temozolomide in anti-melanoma therapy by suppressing the STAT3 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Temozolomide (TMZ) is a first-line therapeutic medication for melanoma. Nonetheless, it exhibits a relatively elevated toxicity profile, and falls short in terms of both effectiveness and median survival rate. Clinical research has demonstrated that the integration of traditional Chinese medicine (TCM) with chemotherapy in the treatment of melanoma can enhance efficacy and reduce toxicity. A TCM formula (SLE) containing Lonicera japonica Thunb. and Robinia pseudoacacia L. has shown anti-melanoma properties through the inhibition of STAT3 phosphorylation. In the genesis and advancement of melanoma, the STAT3 signaling pathway is essential. AIM OF THE STUDY: The aim of this study was to evaluate the effect of SLE combined with TMZ (SLE/TMZ) in inhibiting melanoma, and to explore the contribution of inhibiting the STAT3 signaling pathway in this effect. MATERIALS AND METHODS: Both A375 cells and B16F10 tumor-bearing mice were used for in vitro and in vivo experiments, respectively. In vitro assays included CCK8, crystal violet staining, flow cytometry, qRT-PCR, and Western blotting. Animal experiment indicators included tumor volume, tumor weight, mouse weight, and the proportion of mouse immune cells. RESULTS: SLE/TMZ inhibited the proliferation and growth of A375 cells, and also induced apoptosis. Additionally, SLE/TMZ synergistically inhibited tumor growth in the B16F10 melanoma mouse model and had immunomodulatory effects, increasing the proportion of Th, Tc, and NK cells and decreasing the proportion of MDSCs in the spleen of melanoma-bearing mice. qRT-PCR and Western blotting results confirmed that SLE/TMZ inhibited STAT3 phosphorylation and regulated its downstream factors, including Bcl2, Mcl1, CCND1, MYC, MMP2, MMP9, VEGFA, and FGF2. The inhibitory effect of SLE/TMZ on melanoma cell growth was considerably lessened when STAT3 was overexpressed at the cellular level. CONCLUSION: Synergistic anti-melanoma effects of SLE/TMZ have been observed in animal and cellular models. One of the mechanisms of SLE/TMZ that underlies its anti-melanoma actions is inhibition of the STAT3 pathway. This work offers pre-clinical pharmacological backing for the advancement of SLE as a therapeutic agent to be used in conjunction with TMZ for the treatment of melanoma.

Inhibition of STAT3 by 2-Methoxyestradiol suppresses M2 polarization and protumoral functions of macrophages in breast cancer.

BACKGROUND: Breast cancer metastasis remains the leading cause of cancer-related deaths in women worldwide. Infiltration of tumor-associated macrophages (TAMs) in the tumor stroma is known to be correlated with reduced overall survival. The inhibitors of TAMs are sought after for reprogramming the tumor microenvironment. Signal transducer and activator of transcription 3 (STAT3) is well known to contribute in pro-tumoral properties of TAMs. 2-Methoxyestradiol (2ME2), a potent anticancer and antiangiogenic agent, has been in clinical trials for treatment of breast cancer. Here, we investigated the potential of 2ME2 in modulating the pro-tumoral effects of TAMs in breast cancer. METHODS: THP-1-derived macrophages were polarized to macrophages with or without 2ME2. The effect of 2ME2 on macrophage surface markers and anti-inflammatory genes was determined by Western blotting, flow cytometry, immunofluorescence, qRT‒PCR. The concentration of cytokines secreted by cells was monitored by ELISA. The effect of M2 macrophages on malignant properties of breast cancer cells was determined using colony formation, wound healing, transwell, and gelatin zymography assays. An orthotopic model of breast cancer was used to determine the effect of 2ME2 on macrophage polarization and metastasis in vivo. RESULTS: First, our study found that polarization of monocytes to alternatively activated M2 macrophages is associated with the reorganization of the microtubule cytoskeleton. At lower concentrations, 2ME2 treatment depolymerized microtubules and reduced the expression of CD206 and CD163, suggesting that it inhibits the polarization of macrophages to M2 phenotype. However, the M1 polarization was not significantly affected at these concentrations. Importantly, 2ME2 inhibited the expression of several anti-inflammatory cytokines and growth factors, including CCL18, TGF-ß, IL-10, FNT, arginase, CXCL12, MMP9, and VEGF-A, and hindered the metastasis-promoting effects of M2 macrophages. Concurrently, 2ME2 treatment reduced the expression of CD163 in tumors and inhibited lung metastasis in the orthotopic breast cancer model. Mechanistically, 2ME2 treatment reduced the phosphorylation and nuclear translocation of STAT3, an effect which was abrogated by colivelin. CONCLUSIONS: Our study presents novel findings on mechanism of 2ME2 from the perspective of its effects on the polarization of the TAMs via the STAT3 signaling in breast cancer. Altogether, the data supports further clinical investigation of 2ME2 and its derivatives as therapeutic agents to modulate the tumor microenvironment and immune response in breast carcinoma.

Interleukin 6 and cancer resistance in glioblastoma multiforme.

Despite unprecedented survival in patients with glioblastoma (GB), the aggressive primary brain cancer remains largely incurable and its mechanisms of treatment resistance have gained particular attention. The cytokine interleukin 6 (IL-6) and its receptor weave through the hallmarks of malignant gliomas and may represent a key vulnerability to GB. Known for activating the STAT3 pathway in autocrine fashion, IL-6 is amplified in GB and has been recognized as a negative biomarker for GB prognosis, rendering it a putative target of novel GB therapies. While it has been recognized as a biologically active component of GB for three decades only with concurrent advances in understanding of complementary immunotherapy has the concept of targeting IL-6 for a human clinical trial gained scientific footing.

IL-22 resolves MASLD via enterocyte STAT3 restoration of diet-perturbed intestinal homeostasis.

The exponential rise in metabolic dysfunction-associated steatotic liver disease (MASLD) parallels the ever-increasing consumption of energy-dense diets, underscoring the need for effective MASLD-resolving drugs. MASLD pathogenesis is linked to obesity, diabetes, "gut-liver axis" alterations, and defective interleukin-22 (IL-22) signaling. Although barrier-protective IL-22 blunts diet-induced metabolic alterations, inhibits lipid intake, and reverses microbial dysbiosis, obesogenic diets rapidly suppress its production by small intestine-localized innate lymphocytes. This results in STAT3 inhibition in intestinal epithelial cells (IECs) and expansion of the absorptive enterocyte compartment. These MASLD-sustaining aberrations were reversed by administration of recombinant IL-22, which resolved hepatosteatosis, inflammation, fibrosis, and insulin resistance. Exogenous IL-22 exerted its therapeutic effects through its IEC receptor, rather than hepatocytes, activating STAT3 and inhibiting WNT-ß-catenin signaling to shrink the absorptive enterocyte compartment. By reversing diet-reinforced macronutrient absorption, the main source of liver lipids, IL-22 signaling restoration represents a potentially effective interception of dietary obesity and MASLD.

CXCR4 orchestrates the TOX-programmed exhausted phenotype of CD8+ T cells via JAK2/STAT3 pathway.

Evidence from clinical trials suggests that CXCR4 antagonists enhance immunotherapy effectiveness in several cancers. However, the specific mechanisms through which CXCR4 contributes to immune cell phenotypes are not fully understood. Here, we employed single-cell transcriptomic analysis and identified CXCR4 as a marker gene in T cells, with CD8+PD-1high exhausted T (Tex) cells exhibiting high CXCR4 expression. By blocking CXCR4, the Tex phenotype was attenuated in vivo. Mechanistically, CXCR4-blocking T cells mitigated the Tex phenotype by regulating the JAK2-STAT3 pathway. Single-cell RNA/TCR/ATAC-seq confirmed that Cxcr4-deficient CD8+ T cells epigenetically mitigated the transition from functional to exhausted phenotypes. Notably, clinical sample analysis revealed that CXCR4+CD8+ T cells showed higher expression in patients with a non-complete pathological response. Collectively, these findings demonstrate the mechanism by which CXCR4 orchestrates CD8+ Tex cells and provide a rationale for combining CXCR4 antagonists with immunotherapy in clinical trials.

pSTAT3 activation of Foxl2 initiates the female pathway underlying temperature-dependent sex determination.

Ovarian development was traditionally recognized as a "default" sexual outcome and therefore received much less scientific attention than testis development. In turtles with temperature-dependent sex determination (TSD), how the female pathway is initiated to induce ovary development remains unknown. In this study, we have found that phosphorylation of the signal transducer and activator of transcription 3 (pSTAT3) and Foxl2 exhibit temperature-dependent sexually dimorphic patterns and tempo-spatial coexpression in early embryos of the red-eared slider turtle (Trachemys scripta elegans). Inhibition of pSTAT3 at a female-producing temperature of 31 °C induces 64.7% female-to-male sex reversal, whereas activation of pSTAT3 at a male-producing temperature of 26 °C triggers 75.6% male-to-female sex reversal. In addition, pSTAT3 directly binds to the locus of the female sex-determining gene Foxl2 and promotes Foxl2 transcription. Overexpression or knockdown of Foxl2 can rescue the sex reversal induced by inhibition or activation of pSTAT3. This study has established a direct genetic link between warm temperature-induced STAT3 phosphorylation and female pathway initiation in a TSD system, highlighting the critical role of pSTAT3 in the cross talk between female and male pathways.

Anti-Cancer Potential of Isoflavone-Enriched Fraction from Traditional Thai Fermented Soybean against Hela Cervical Cancer Cells.

Cervical cancer is a leading cause of gynecological malignancies and cancer-related deaths among women worldwide. This study investigates the anti-cancer activity of Thua Nao, a Thai fermented soybean, against HeLa cervical carcinoma cells, and explores its underlying mechanisms. Our findings reveal that the ethyl acetate fraction of Thua Nao (TN-EA) exhibits strong anti-cancer potential against HeLa cells. High-performance liquid chromatography (HPLC) analysis identified genistein and daidzein as the major isoflavones in TN-EA responsible for its anti-cancer activity. TN-EA and genistein reduced cell proliferation and induced G2/M phase arrest, while daidzein induced G1 arrest. These responses were associated with the downregulation of cell cycle regulators, including Cyclin B1, cycle 25C (Cdc25C), and phosphorylated cyclin-dependent kinase 1 (CDK-1), and the upregulation of the cell cycle inhibitor p21. Moreover, TN-EA and its active isoflavones promoted apoptosis in HeLa cells through the intrinsic pathway, evidenced by increased levels of cleaved Poly (ADP-ribose) polymerase (PARP) and caspase-3, loss of mitochondrial membrane potential, and the downregulation of anti-apoptotic proteins B-cell leukemia/lymphoma 2 (Bcl-2), B-cell lymphoma-extra-large (Bcl-xL), cellular inhibitor of apoptosis proteins 1 (cIAP), and survivin. Additionally, TN-EA and its active isoflavones effectively reduced cell invasion and migration by downregulating extracellular matrix degradation enzymes, including Membrane type 1-matrix metalloproteinase (MT1-MMP), urokinase-type plasminogen activator (uPA), and urokinase-type plasminogen activator receptor (uPAR), and reduced the levels of the mesenchymal marker N-cadherin. At the molecular level, TN-EA suppressed STAT3 activation via the regulation of JNK and Erk1/2 signaling pathways, leading to reduced proliferation and invasion of HeLa cells.