STAT proteins in cancer: orchestration of metabolism

Dimethyl fumarate ameliorated pyroptosis in contrast-induced acute renal injury by regulating endoplasmic reticulum stress and JAK2-STAT3 pathway

BACKGROUND

Inflammation and oxidative stress are important pathological processes of contrast-induced acute renal injury (CIAKI). This study explored whether DMF had therapeutic effects and investigated the underlying mechanism in CIAKI.

METHODS

A CIAKI animal model was established in C57BL/6J mice with iohexol, and DMF was used as an intervention. In vitro, HK-2 cells were treated with iohexol and DMF. RNA-seq analysis was performed on the renal tissue of the mice. Protein-protein interaction (PPI), and enrichment analysis were subsequently conducted. In addition, endoplasmic reticulum stress (ERS) activation and STAT3 inhibition were used to study the relationships among ERS, the JAK2-STAT3 pathway and pyroptosis.

RESULTS

DMF improved the renal function of CIAKI model mice. Enrichment analysis revealed that the differentially expressed genes (DEGs) were enriched mostly in the acute phase response and the JAK-STAT pathway. The results revealed that inflammation, ERS and pyroptosis increased in the CIAKI group but decreased after DMF treatment. Further study revealed that the JAK2-STAT3 pathway was overactivated in vivo and in vitro and that DMF inhibited the JAK2-STAT3 pathway. In addition, ERS activation could increase the JAK2-STAT3 pathway and pyroptosis, while STAT3 knockdown could reverse pyroptosis, indicating that ERS could activate the JAK2-STAT3 pathway, further triggering pyroptosis. DMF ameliorated pyroptosis through regulating ERS and the JAK2-STAT3 pathway in CIAKI.

CONCLUSION

This study demonstrated that DMF had renoprotective effects on CIAKI. DMF ameliorated pyroptosis through the inhibition of ERS and the JAK2-STAT3 pathway.

Indole-3-lactic acid suppresses colorectal cancer via metabolic reprogramming

Research indicates that abnormal gut microbiota metabolism is linked to colorectal cancer (CRC) progression, but the role of microbiota-related tryptophan metabolism disruption remains unclear. Using metagenomic sequencing and targeted Trp metabolomics, our research identified that CRC patients had abnormal indole-3-lactic acid (ILA) levels, which were related to tumor malignancy. Exogenous ILA administration suppressed CRC development in AOM/DSS induced and xenograft mice models. Furthermore, in vitro experiments demonstrated that ILA inhibits tumor cell proliferation, migration, and anti-apoptotic capabilities. Mechanistically, ILA appears to directly occupy the phosphorylation sites of STAT3, leading to a reduction in intracellular phosphorylated STAT3 (p-STAT3) levels and the inhibition of the HK2 pathway, thereby downregulating glucose metabolism in cancer cells. Notably, this inhibition is independent of the aryl hydrocarbon receptor (AHR). In conclusion, our research findings demonstrate that alterations in tryptophan metabolism among CRC patients can influence tumor progression and reveal a novel mechanism through which ILA exerts its inhibitory effects on CRC. These findings offer new insights into the role of gut microbiota in CRC and identify potential clinical therapeutic targets.

Brain-targeted polymersomes mediating RNAi of STAT3 sensitize glioblastoma to temozolomide and immunotherapy

Glioblastoma (GBM) is among the most aggressive brain tumors, presenting significant therapeutic challenges due to intrinsic and acquired resistance to treatment, alongside a highly immunosuppressive tumor microenvironment (TME). While temozolomide (TMZ) is the standard chemotherapeutic agent with the ability to penetrate the blood-brain barrier (BBB), its clinical efficacy is often limited. Here, we report a strategy employing Apolipoprotein E (ApoE) peptide-functionalized polymersomes loaded with small interfering RNA (siRNA) targeting signal transducer and activator of transcription 3 (Apstat3) to amplify the anti-GBM effects of TMZ and immunotherapy. Apstat3 demonstrated small, uniform particle sizes, stability in siRNA encapsulation, and effective downregulation of STAT3 and O⁶-methylguanine-DNA methyltransferase (MGMT) in GL261 cells, sensitizing these tumor cells to TMZ. The combinatorial approach not only significantly inhibited GBM cell proliferation, migration and invasion but also improved dendritic cells (DCs) maturation under TME-mimicking environment. In orthotopic GL261 mouse models, intravenous injection of Apstat3 co-administered with oral TMZ resulted in a twofold increase in median survival and reshaped the TME. Notably, combined treatment with anti-CTLA4 therapy tripled median survival to 64 days, achieving complete remission observed in 20% of the mice. This siSTAT3 delivery strategy holds promise for enhancing GBM treatment outcomes.

Crosstalk of glutamine metabolism between cancer-associated fibroblasts and cancer cells

Glutamine (Gln), a critical metabolic substrate, fuels the uncontrolled proliferation of cancer cells. Cancer-associated fibroblasts (CAFs), essential components of the tumor microenvironment, facilitate tumor progression by supplying Gln to cancer cells and driving drug resistance through metabolic reprogramming. This review highlights the key processes of Gln uptake, transport, and catabolism and explores the metabolic crosstalk between CAFs and cancer cells. It also examines the roles of major oncogenic regulators-c-Myc, mTORC, KRAS, p53, and HIF-in controlling Gln metabolism and shaping therapeutic resistance. Current pharmacological approaches targeting Gln metabolism, including enzyme inhibitors and transporter blockers, are discussed alongside emerging therapeutic strategies and ongoing clinical trials. Lastly, we underscore the importance of integrating advanced technologies like artificial intelligence and spatial omics to refine treatment targeting and develop more effective, personalized therapeutic interventions.

The role of quercetin in modulating lipid metabolism and enhancing chemotherapy via the STAT3-CPT1B pathway in pancreatic cancer

BACKGROUND

Pancreatic cancer is a highly aggressive gastrointestinal tumor with limited treatment options, such as surgery and chemotherapy. Thus, further research into its pathogenesis and new treatments is necessary.

METHODS

Fluorescence-activated cell sorting was employed to sort pancreatic cancer stem cells (PCSCs). Sphere formation assays and Cell Counting Kit-8 (CCK-8) assays were conducted to assess stemness and proliferation capacity. Quantitative real-time PCR and Western blot analysis were employed to assess gene expression levels. Furthermore, immunofluorescence microscopy and chromatin immunoprecipitation assays were conducted to examine alterations in signaling pathways and gene expression.

RESULTS

Quercetin and gemcitabine may inhibit PANC-1 cells and PCSCs by affecting energy metabolism. Chromatin immunoprecipitation assays revealed an interaction between STAT3 and CPT1B in PCSCs. Quercetin and gemcitabine might affect energy metabolism by inhibiting STAT3 and CPT1B. Manipulating STAT3 expression (overexpression plasmids and siRNA knockdown) altered CPT1B mRNA and protein expression. Although acetyl-CoA reversed the quercetin- and gemcitabine-induced expression of N-cadherin, DECR1, and ALDH, it had minimal influence on CPT1B and STAT3 levels.

CONCLUSION

Quercetin inhibits the expression of CPT1B via the STAT3 signaling pathway, affecting lipid metabolism and exerting antitumor effects. Furthermore, the combined administration of quercetin and gemcitabine exhibits enhanced therapeutic efficacy.

Exploring the novel role and mechanistic insights of skeletal muscle relaxant cyclobenzaprine hydrochloride in esophageal squamous cell carcinoma treatment

OBJECTIVE

Cyclobenzaprine hydrochloride (Flexeril) is a muscle relaxant primarily used to relieve muscle pain and spasms. However, its potential anti-cancer role remains largely unexplored. This study aims to investigate the inhibitory effect of Flexeril on esophageal squamous cell carcinoma (ESCC) and to uncover the molecular mechanisms through which it affects the proliferation and metastasis of ESCC.

METHODS

A compound library approved by the FDA was employed to screen drugs with inhibitory effects on ESCC. Cell viability was assessed using the Cell Counting Kit-8 (CCK-8) assay, and Plate colony formation was analyzed to evaluate the proliferative ability of ESCC cell lines (KYSE150 and Eca109) after treatment with Flexeril. Migratory ability was examined through Transwell and Scratch assays. Proteomics was performed to identify proteins regulated by Flexeril in KYSE150 and Eca109 cells. RT-PCR and Western blot were used to detect changes in related genes at the mRNA and protein levels after treatment with Flexeril. Drug affinity responsive target stability (DARTS) assay and cellular thermal shift assay (CETSA) were employed to identify the binding of Flexeril and JAK1 protein. Additionally, the comet assay was conducted to assess the DNA damage response in ESCC cells following WDHD1 knockdown or Flexeril exposure. Finally, tumor‑bearing nude mice model were constructed to evaluate the in vivo anticancer effects of Flexeril on ESCC.

RESULTS

Flexeril significantly inhibited the proliferation and migration of ESCC cells in a time- and dose-dependent manner. Proteomics analysis identified WDHD1 as a downstream target of Flexeril exposure, and knockdown of WDHD1 mimicked the effects of Flexeril on proliferation and migration of ESCC. Conversely, overexpression of WDHD1 attenuated the inhibitory effects of Flexeril on ESCC. Mechanistically, the JAK1-STAT3 signaling pathway, but not the JAK2-STAT3 or PI3K-Akt-mTOR pathways, was involved in regulating WDHD1 expression in ESCC cells following Flexeril treatment. Overexpression of STAT3 or WDHD1 mitigated the inhibitory effects of Flexeril on ESCC proliferation and migration. Moreover, both Flexeril exposure and WDHD1 knockdown induced a DNA damage response (DDR) in ESCC cells. In addition, Flexeril significantly inhibited the growth of ESCC tumors in nude mice, downregulating the JAK1-STAT3-WDHD1 signaling pathway, with no significant damage observed in vital organs such as the heart, liver, spleen, lungs, or kidneys, as shown by histological examination.

CONCLUSION

Flexeril exhibits anti-cancer effects in ESCC by inhibiting the JAK1-STAT3-WDHD1 axis and inducing DDR. These findings suggest that Flexeril may serve as a potential novel therapeutic agent for the treatment of ESCC.

Lactobacillus plantarum-derived extracellular vesicles from dietary barley leaf supplementation attenuate Citrobacter rodentium infection and intestinal inflammation

BACKGROUND

Inflammatory bowel disease (IBD) is a gastrointestinal inflammatory disorder characterized by disturbed interactions between gut microbiota and host immune response. Barley leaf (BL) is a traditional Chinese herb recorded to have health-promoting effects. However, little is known about the beneficial role of BL against enteric infection-induced intestinal inflammation. Here, we uncover that BL protects against Citrobacter rodentium (C. rodentium)-induced infectious colitis by improving host-microbiota interactions.

METHODS

C3H/HeN mice were fed a diet with/without BL and infected with C. rodentium. Transcriptome sequencing, anti-CD4 antibody treatment, and flow cytometry were conducted to investigate the mechanisms of T cell immune modulation. The intervention involved administering anti-CD4 antibody at 500 µg each time for three times before and during C. rodentium infection. Analysis of gut microbiota composition was performed by 16S rRNA gene sequencing on fecal samples. Fecal microbiota transplantation was conducted by administering microbiota from donor group to recipient group via oral gavage to investigate the role of intestinal microbiota in immune modulation.

RESULTS

BL ameliorated the severity of C. rodentium-induced colitis, and this effect was linked to improved gut homeostasis and enhanced mucosal barrier function. BL enriched the pathways of T helper 1 (Th1)/Th2 and Th17 cell differentiation in the colon, suggesting the involvement of CD4+ T cells. Consistent with this, anti-CD4 antibody treatment abrogated the effect of BL and flow cytometry analysis revealed that BL mitigated C. rodentium-induced pro-inflammatory Th1 immune response. Moreover, the protective effect of BL was associated with alleviation of gut microbiota dysbiosis and increased abundance of Lactobacillus. Our in vivo studies further revealed that live Lactobacillus plantarum (L. plantarum) administration attenuated the pathogenic effects induced by C. rodentium infection, whereas heat-inactivated L. plantarum did not show the same results. Mechanistically, BL supplementation enriched L. plantarum, which subsequently released nanosized extracellular vesicles (EVs) that serve as a key mediator in alleviating C. rodentium-associated pathology and Th1 cell dysregulation.

CONCLUSIONS

Our work thus provides evidence for utilizing BL and L. plantarum-derived EVs to manage enteric infection-associated IBD.

Linghe granules reduces hepatic lipid accumulation in Non-alcoholic fatty liver disease through regulating lipid metabolism and redox balance

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a prevalent liver disorder with no approved pharmacological therapies. Linghe granules, a hospital-based formulation derived from a classic prescription, have demonstrated potential in reducing hepatic fat accumulation and improving metabolic health. This study provides a novel, comprehensive assessment of Linghe granules, integrating clinical, preclinical, and molecular analyses for NAFLD management.

PURPOSE

This study aims to evaluate the therapeutic efficacy of Linghe granules in alleviating NAFLD through an integrated approach.

METHODS

A clinical trial involving 40 patients with NAFLD was conducted, with participants divided into a control group (lifestyle interventions) and a treatment group (lifestyle interventions plus oral Linghe granules). Various metabolic and liver function indicators were assessed before and after treatment. Additionally, a high-fat diet (HFD) was used to induce a NAFLD model in rat, followed by treatment with different doses of Linghe granules. In vitro studies on HepG2 and L02 cells were performed to the effects of the granules on lipid metabolism. Transcriptomic profiling, Weighted Gene Co-expression Network Analysis (WGCNA), Dynamic Network Biomarkers (DNB) analysis, and molecular docking were employed to explore the underlying mechanisms.

RESULTS

Linghe granules led to significant reductions in BMI, liver enzymes (AST, ALT), triglycerides, LDL-C, and GGT in patients with NAFLD, accompanied by a notable decrease in hepatic fat accumulation. In the rat model, treatment improved liver weight, liver function, and lipid metabolism. In vitro, Linghe granules decreased lipid accumulation and regulated key lipid metabolism markers, including sterol regulatory element-binding protein 1 (SREBP-1), stearoyl-CoA desaturase 1 (SCD1), and fatty acid-binding protein 5 (FABP5). Mechanistic analyses revealed that Linghe granules modulated oxidative stress-related pathways and genes involved in lipid metabolism.

CONCLUSION

This study represents the first integrated evaluation of Linghe granules' efficacy and mechanisms in treating NAFLD, demonstrating their potential to improve liver function, reduce lipid accumulation, and modulate key metabolic markers. These results suggest that Linghe granules may serve as an effective adjunctive treatment for NAFLD.

STK31 drives tumor immune evasion through STAT3-IL-6 mediated CD8+ T cell exhaustion

Dysregulations in protein kinases significantly contribute to the initiation, progression, and drug resistance in non-small cell lung cancer (NSCLC). Identification of novel oncogenic drivers within the human kinome is crucial for targeted therapy. In this study, we conducted a comprehensive analysis of the TCGA database and literature, pinpointing 16 candidate genes in lung cancer exhibiting frequent dysregulation and limited research. Our functional analysis revealed Serine/threonine kinase 31 (STK31) as a key player in driving tumor growth, in immune-competent mice, with minimal impact in nude mice. Further investigations unveiled upregulation of STK31 led to CD8+ T cell exhaustion. Mechanistically, STK31 induced CD8+ T cell exhaustion through the signal transducer and activator of transcription 3 (STAT3) - interleukin 6 (IL-6) signaling pathway. Direct interaction between STK31 and STAT3 activated the transcription of downstream oncogenic targets, such as IL-6, facilitating immune escape. Moreover, STK31 exhibited elevated expression levels in lung cancer tissues compared to adjacent tissues and displayed a significant correlation with poor prognosis in lung cancer patients. This study defines a critical role of STK31 in promoting immune escape through STAT3 activation, positioning it as a promising therapeutic target for lung cancer.

The key regulator circPDE3B promotes arsenic-induced bladder carcinogenesis by affecting STAT3 and NF-κB stability

Long-term exposure to arsenic (As), which is a ubiquitous environmental contaminant, significantly enhances the risk of multiple cancers, including bladder and lung cancers. In recent years, the important roles of circular RNAs (circRNAs) in tumorigenesis and development have attracted widespread attention. However, the specific molecular mechanisms by which circRNAs promote bladder cancer development following exposure to arsenic remain incompletely understood. This study is the first to demonstrate that circPDE3B is significantly upregulated in a cell model of transformation triggered by arsenic and that it promotes this transformation process. Our study elucidated the biological function of circPDE3B in vitro, in SV-HUC-1 cells, showing that it accelerates the malignant transformation from arsenic via increasing cell proliferation and inhibiting apoptosis. Furthermore, we delineated a novel molecular mechanism whereby circPDE3B directly binds to NF-κB and STAT3, inhibiting their ubiquitination and increasing their stability. This, in turn, affects downstream HIF-1α expression, promoting the malignant transformation of SV-HUC-1 cells and eventually resulting in bladder carcinogenesis. Our research reveals the critical regulatory role of circPDE3B in the arsenic-triggered malignant transformation within SV-HUC-1 cells. This study offers broader perspectives on the molecular mechanisms driving bladder cancer progression, while also identifying potential targets for early diagnosis and treatment of bladder tumour.

L-Kynurenine regulates immune response in ICIs-associated myocarditis via JAK/STAT pathway

BACKGROUND

Immune checkpoint inhibitor associated myocarditis (ICIAM) is a drug-induced myocarditis characterized by the infiltration of immune cells into cardiac. However, the mechanisms are unknown and effective drug therapies are lacking in clinical practice. This study aims to explore the relationship between plasma metabolites and the treatment of ICIAM.

METHODS

Human plasma metabolites were analyzed using untargeted metabolomics for characteristic metabolites. For in vivo experiments, Male Balb/c mice were divided into six groups: PBS, L-Kynurenine, cTNI+PD-1 inhibitor (ICIs), ICIs+L-Kynurenine, ICIs+RO8191, ICIs+RO8191+L-Kynurenine. On day 21 post-modeling, echocardiography, ELISA and histopathology were employed to evaluate the therapeutic effect of L-Kynurenine. Flow cytometry was used to determine the proportion of immune cells in the heart and spleen. Bulk-RNAseq was conducted to analyze differential genes, and q-PCR, immunofluorescence and western blot were performed for validation experiments.

RESULTS

Untargeted metabolomics verified that indoleamine 2,3 dioxygenase-1 (IDO1)-derived L-Kynurenine level was higher in the serum of ICIAM compared to non-ICIAM patients. Meanwhile, in vitro and in vivo experiments showed that L-Kynurenine exhibited a therapeutic ability in ICIAM by inhibiting the pro-inflammatory polarization of immune cells and the secretion of pro-inflammatory cytokines. Mechanistically, L-Kynurenine improved cardiac functions majorly by the inhibition of the JAK1/STAT3 signaling pathway.

CONCLUSION

L-Kynurenine exhibits significant therapeutic potential in ICIAM. The multi-roles of L-Kynurenine in regulating immune responses make it possible to be used as a targeted drug for ICIAM therapy.

Synergistic effects and mechanism of recombinant viral vector-mediated STAT1 overexpression and STAT3 silencing on glioma U251 apoptosis

BACKGROUND

In the present study, the synergistic effects and mechanism of recombinant viral vector-mediated co-expression plasmids stat1 and stat3-siRNA on glioma were investigated in vivo and in vitro.

METHODS

Co-expression plasmids for stat1/stat3-siRNA were constructed and packaged into lentivirus and adenovirus for cell and animal experiments. Real-time PCR and Western blot analyses were used to detect the expression of STAT1 and STAT3 at gene and protein levels in U251 cells. CCK-8, TUNEL, flow cytometry, and cell scratching assays were performed to detect the therapeutic effect of the co-expression plasmid stat1/stat3-siRNA on glioma in vitro. U251 glioma cells were injected into nude mice to observe therapeutic effect of stat1/stat3-siRNA.Transcriptome sequencing was utilized to further explore the possible mechanism.

RESULTS

Treatment of glioma cells and xenograft animal model with the co-expression plasmid stat1/stat3-siRNA led to a significant increase in STAT1 and a marked decrease in STAT3 expression at both mRNA and protein expression levels. Compared to the single-gene stat1 and stat3-siRNA groups, stat1/stat3-siRNA group demonstrated a more pronounced promoting apoptosis of U251, but cell viability and migration, as well as reduced tumor growth in nude mice were not significant. Transcriptome sequencing results indicated that the modulation of multiple nodes within the FOXO signaling pathway may represent the main mechanism by which co-expression of lenti-stat1/stat3-SiRNA induces U251 cell apoptosis.

CONCLUSIONS

The co-expression plasmid stat1/stat3-siRNA significantly induces apoptosis more effectively than individual stat1 and stat3-siRNA constructs. The potential mechanism involves the alternation of multiple nodes in the FOXO signaling pathway.

Downregulation of MPC1 promotes HCC cell proliferation and metastasis via the STAT3 pathway

Hepatocellular carcinoma (HCC) is prevalent globally, and the discovery of new targets is vital for the treatment of HCC. Mitochondrial pyruvate carrier 1 (MPC1) has been found to exhibit reduced expression and promote tumour progression in some cancers, although its role in HCC needs to be explored. Using GEO datasets and Kaplan‒Meier plotter, the clinicopathological features and patient prognosis were analysed by assessing the expression levels of MPC1 in HCC tissues. After MPC1-knockdown and MPC1-overexpressing cell lines were constructed, the effects of modulating MPC1 expression on the malignant phenotype of HCC cells were tested via CCK8, colony formation, and scratch assays and flow cytometry. The effects of MPC1 on HCC cells and mitochondria were examined via MitoTracker Red CMXRos staining, cytoskeleton staining and cellular energy metabolism assays. MPC1 expression was found to be reduced in HCC patients and correlated with prognosis and clinicopathological features. It was found that low expression of MPC1 promotes the malignant phenotype of HCC cells and affects the mitochondrial energy metabolism of HCC cells to support the tumour microenvironment, and that MPC1 may act through signal transducer and activator of transcription 3 (STAT3). MPC1 might play a tumor-suppressing role in HCC through its interaction with STAT3, and this discovery could offer novel perspectives for HCC treatment.

STAT5 and STAT3 balance shapes dendritic cell function and tumour immunity

Immune checkpoint blockade (ICB) has transformed cancer therapy1,2. The efficacy of immunotherapy depends on dendritic cell-mediated tumour antigen presentation, T cell priming and activation3,4. However, the relationship between the key transcription factors in dendritic cells and ICB efficacy remains unknown. Here we found that ICB reprograms the interplay between the STAT3 and STAT5 transcriptional pathways in dendritic cells, thereby activating T cell immunity and enabling ICB efficacy. Mechanistically, STAT3 restrained the JAK2 and STAT5 transcriptional pathway, determining the fate of dendritic cell function. As STAT3 is often activated in the tumour microenvironment5, we developed two distinct PROTAC (proteolysis-targeting chimera) degraders of STAT3, SD-36 and SD-2301. STAT3 degraders effectively degraded STAT3 in dendritic cells and reprogrammed the dendritic cell-transcriptional network towards immunogenicity. Furthermore, STAT3 degrader monotherapy was efficacious in treatment of advanced tumours and ICB-resistant tumours without toxicity in mice. Thus, the crosstalk between STAT3 and STAT5 transcriptional pathways determines the dendritic cell phenotype in the tumour microenvironment and STAT3 degraders hold promise for cancer immunotherapy.

STAT3-mediated upregulation of TRIM6 promotes hepatocellular carcinoma invasion through the DDX58-Snail1 axis

Hepatocellular carcinoma (HCC) is a highly aggressive malignancy with poor prognosis, driven by complex molecular mechanisms that remain inadequately understood. Among these, the ubiquitin-proteasome system plays a crucial role in regulating protein stability and function, with E3 ubiquitin ligases emerging as key players in cancer progression. Here, we identify Tripartite Motif-containing 6 (TRIM6), an E3 ubiquitin ligase, as a critical regulator of HCC metastasis. We demonstrate that TRIM6 is significantly upregulated in HCC tissues and correlates with poor overall survival. Mechanistically, we uncover that STAT3 directly regulates TRIM6 by binding to its promoter and enhancing its transcription. Functionally, TRIM6 promotes epithelial-mesenchymal transition (EMT) and cell invasion by upregulating the key EMT transcription factor Snail1. Importantly, we reveal that TRIM6 interacts with and ubiquitinates DDX58 (RIG-I), leading to its proteasomal degradation. The degradation of DDX58 by TRIM6 alleviates its inhibitory effects on Snail1, thereby facilitating EMT and enhancing the invasive potential of HCC cells. These findings establish the STAT3-TRIM6-DDX58-Snail1 axis as a pivotal pathway in HCC progression, offering novel insights into the molecular underpinnings of HCC metastasis and highlighting TRIM6 as a potential therapeutic target and prognostic biomarker in HCC.

SYT7 accelerates nasopharyngeal carcinoma progression via ALDH1A3-mediated STAT3 signaling activation

Nasopharyngeal carcinoma (NPC) is a special histological and ethical type of head and neck cancer with unsatisfactory clinical outcome. Thus, exploring effective molecular targets is critical for NPC treatment. We observed increased expression levels of synaptotagmin-7 (SYT7) in NPC tissues, which correlated with unfavorable prognoses. Furthermore, knockdown of SYT7 in NPC cells suppressed proliferation and migration rates, and enhanced apoptosis. In contrast, overexpression of SYT7 accelerated NPC tumor growth. Using whole-genome gene arrays and immunoprecipitation-mass spectrometry assays, aldehyde dehydrogenase 1 family member A3 (ALDH1A3), a regulator of glycolytic metabolism, was identified as a critical downstream target of SYT7. Mechanistically, SYT7 binds and promotes ALDH1A3 deubiquitination, resulting in decreased ALDH1A3 degradation. Notably, we also observed an increased expression of ALDH1A3 in NPC. More importantly, the knockdown of ALDH1A3 resulted in suppressed proliferation, migration, glycolysis, and promoted apoptosis, all of which could be restored by the overexpression of SYT7 in NPC cells. Taken together, we found that SYT7 increases ALDH1A3-mediated STAT3 activation and glycolysis, contributing to NPC progression, which provides a possible molecular mechanism for the development of targeted therapeutics interventions.

Integrated analysis identifies P4HA2 as a key regulator of STAT1-mediated colorectal cancer progression and a potential biomarker for precision therapy

Introduction

P4HA2 is implicated in regulating tumor microenvironment formation and may play roles in inflammation and tumor immunity. However, its mechanistic involvement in colorectal cancer (CRC) remains largely unexplored.

Methods

We analyzed P4HA2 expression in CRC tissues and correlated it with clinicopathological features. Functional assays (CCK8, wound healing, Transwell) were performed to assess proliferation and migration. Proteomic analysis identified downstream targets, with STAT1/PD-L1 pathway validation.

Results

High P4HA2 expression correlated with advanced T/M stages and served as an independent poor prognostic factor. Functional experiments confirmed P4HA2's role in promoting CRC proliferation and migration. Mechanistically, P4HA2 bound to and downregulated STAT1, subsequently modulating the STAT1/PD-L1 pathway.

Discussion

Our findings reveal P4HA2 promotes CRC progression and suppresses anti-tumor immunity via STAT1/PD-L1 axis regulation. This study uncovers a novel pathogenic mechanism, positioning P4HA2 as a potential therapeutic target in CRC.

Metabolic-Immune Suppression Mediated by the SIRT1-CX3CL1 Axis Induces Functional Enhancement of Regulatory T Cells in Colorectal Carcinoma

Metabolic reprogramming of tumor cells dynamically reshapes the distribution of nutrients and signals in the tumor microenvironment (TME), affecting intercellular interactions and resulting in metabolic immune suppression. Increased glucose uptake and metabolism are characteristic of many tumors. Meanwhile, the progression of colorectal carcinoma (CRC) relies on lipid metabolism. Therefore, investigating the role of glucolipid metabolic reprogramming on tumor immunity contributes to identifying new targets for immune suppression intervention in CRC. Our previous work demonstrated that SIRT1 is the hub gene involved in glucolipid metabolic conversion in CRC. Here, it is found that upregulated SIRT1 in CRC cells increases Treg functionality by promoting the secretion of CX3CL1. The CX3CL1-CX3CR1 signaling activated transcription factors SATB1 and BTG2, promoting the differentiation of TCF7+ Treg cells into functionally enhanced TNFRSF9+ Treg cells. Multiplex immunofluorescence (mIHC) analysis of a CRC tissue microarray confirmed the promoting effect of CX3CL1 on Treg infiltration. Additionally, the therapeutic efficacy of CX3CR1 inhibitor monotherapy and combination therapy is validated with the PD-1 antibody in the humanized subcutaneous CRC mouse model. This study elucidates a potential mechanism that metabolic reprogramming of cancer cells collaborates with subsequent immunosuppression to promote CRC progression.

Integration of Bioinformatics and Machine Learning Strategies Identifies Ferroptosis and Immune Infiltration Signatures in Peri-Implantitis

Peri-implantitis (PI) is a chronic inflammatory disease that ultimately leads to the dysfunction and loss of implants with established osseointegration. Ferroptosis has been implicated in the progression of PI, but its precise mechanisms remain unclear. This study explores the molecular mechanisms of ferroptosis in the pathology of PI through bioinformatics, offering new insights into its diagnosis and treatment. The microarray datasets for PI (GSE33774 and GSE106090) were retrieved from the GEO database. The differentially expressed genes (DEGs) and ferroptosis-related genes (FRGs) were intersected to obtain PI-Ferr-DEGs. Using three machine learning algorithms, the Least Absolute Shrinkage and Selection Operator (LASSO), Support Vector Machine-Recursive Feature Elimination (SVM-RFE), and Boruta, we successfully identified the most crucial biomarkers. Additionally, these key biomarkers were validated using a verification dataset (GSE223924). Gene set enrichment analysis (GSEA) was also utilized to analyze the associated gene enrichment pathways. Moreover, immune cell infiltration analysis compared the differential immune cell profiles between PI and control samples. Also, we targeted biomarkers for drug prediction and conducted molecular docking analysis on drugs with potential development value. A total of 13 PI-Ferr-DEGs were recognized. Machine learning and validation confirmed toll-like receptor-4 (TLR4) and FMS-like tyrosine kinase 3 (FLT3) as ferroptosis biomarkers in PI. In addition, GSEA was significantly enriched by the biomarkers in the cytokine-cytokine receptor interaction and chemokine signaling pathway. Immune infiltration analysis revealed that the levels of B cells, M1 macrophages, and natural killer cells differed significantly in PI. Ibudilast and fedratinib were predicted as potential drugs for PI that target TLR4 and FLT3, respectively. Finally, the occurrence of ferroptosis and the expression of the identified key markers in gingival fibroblasts under inflammatory conditions were validated by RT-qPCR and immunofluorescence analysis. This study identified TLR4 and FLT3 as ferroptosis and immune cell infiltration signatures in PI, unraveling potential novel targets to treat PI.

The roles of enhancer, especially super-enhancer-driven genes in tumor metabolism and immunity

Abnormal metabolism is a characteristic of malignant tumors. Numerous factors play roles in the regulation of tumor metabolism. As epigenetic regulators, enhancers, especially the super-enhancers (SEs), serve as platforms for transcription factors that regulate the expression of metabolism-related enzymes or transporters at the gene level. In this study, we review the effects of enhancer/ SE-driven genes on tumor metabolism and immunity. Enhancers/SEs play regulatory roles in glucose metabolism (glycolysis, gluconeogenesis, tricarboxylic acid (TCA) cycle, pyruvate, and pentose phosphate pathway, lipid metabolism (cholesterol, fatty acid, phosphatide, and sphingolipid), and amino acid metabolism (glutamine, tryptophan, arginine, and cystine). By regulating tumor metabolism, enhancers and SEs can reprogram tumor microenvironment, especially the status of various immune cells. Therefore, interfering enhancers/SEs that regulate the tumor metabolism is likely to enhance the effectiveness of immunotherapy.

The effects of interleukin-21 in the biology of transplant rejection

Interleukin-21 (IL-21) is a cytokine that plays a crucial role in regulating immune responses, affecting various immune cell types, including T cells, B cells, natural killer (NK) cells, and dendritic cells. IL-21 is primarily produced by CD4+ T cells, particularly follicular helper T (Tfh) cells and Th17 cells, and has been shown to be extensively involved in regulating both innate and adaptive immunity. IL-21 is particularly significant in the differentiation, proliferation, and effector functions of T cells and B cells. In the context of organ transplantation, IL-21 contributes to the promotion of acute transplant rejection and the development of chronic rejection, which is primarily antibody-mediated. This review summarizes relevant studies on IL-21 and discusses its multifaceted roles in transplant immune rejection, providing insights into therapeutic strategies for either inhibiting graft rejection or promoting tolerance. It also explores the feasibility of blocking the IL-21 signaling pathway within current immunosuppressive regimens, aiming to provide further clinical references.

Research on Peripheral Nerve Aging and Degeneration: Cellular Changes and Mechanism Exploration From the Perspective of Single-Cell Sequencing

As age increases, there are structural and functional alterations in the peripheral nervous system (PNS), significantly affecting movement, sensation and autonomic function. Understanding the characteristics and mechanisms of PNS aging is crucial for preventing and treating related diseases. This study employed single-cell sequencing technology to analyse the dorsal root ganglia (DRG) and sciatic nerve (SN) of aging rats, in comparison with adult rats. The research investigated the mechanisms underlying PNS aging and degeneration, revealing the transcriptional profiles of various cell types. Significant differences were observed in the proportion of Schwann cells between the DRG and SN of adult and aged rats. The Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO) and Gene Set Enrichment Analysis (GSEA) revealed that pathways related to neurodegeneration were upregulated in Schwann cells. Additionally, lipid metabolism pathways were upregulated in the SN of aged rats, suggesting that certain lipid signalling molecules may influence cell proliferation. Through further re-clustering of myelinating Schwann cells, six distinct subtypes were identified. The anti-aging protein protocadherin 9 (PCDH9) was preliminarily screened and found to be significantly downregulated with age. In vitro experiments confirmed that PCDH9 expression is associated with Schwann cell proliferation and differentiation. By using gene expression analysis and cell type across several age groups, this study offers important insights into the mechanisms of PNS aging and degeneration.

CXCL6 Reshapes Lipid Metabolism and Induces Neutrophil Extracellular Trap Formation in Cholangiocarcinoma Progression and Immunotherapy Resistance

The chemokine CXCL6 is identified as a pivotal regulator of biological processes across multiple malignancies. However, its function in cholangiocarcinoma (CCA) is underexplored. Tumor profiling for CXCL6 is performed using a public database. Both in vitro and in vivo experiments are utilized to evaluate the oncogenic effects of CXCL6 on CCA. Additionally, RNA-Seq is employed to detect transcriptomic changes related to CXCL6 expression in CCA cells and neutrophils. Molecular docking, fluorescence colocalization, and Co-IP are used to elucidate a direct interaction between JAKs and CXCR1/2. Additionally, LC-MS lipidomics and explored the impact of CXCL6 on immunotherapy in vivo. CXCL6 is upregulated in CCA tissues and promoted the proliferation and metastasis of CCA. Mechanistically, CXCL6 regulated the CXCR1/2-JAK-STAT/PI3K axis in CCA via autocrine signaling, leading to lipid metabolic reprogramming, and promoted neutrophil extracellular traps (NETs) formation by activating the RAS/MAPK pathway in neutrophils. Eventually, NETs formation induced immunotherapy resistance in CCA by blocking CD8+T cell infiltration. CXCL6 modulates CCA progression through the CXCR1/2-JAK-STAT/PI3K axis and reshaping its lipid metabolism. CXCL6 also mediates immunotherapy resistance through NETs, which may be a potential therapeutic target and biomarker for CCA.

Novel inhibitors of STAT3: an updated patent review (2022-present)

INTRODUCTION

Signal transducer and activator of transcription 3 (STAT3), a member of the STAT protein family, serves as both a signal transducer and a transcription factor. Previous studies have highlighted its pivotal roles in regulating cell proliferation, differentiation, apoptosis, as well as immune and inflammatory responses. Consequently, targeting STAT3 has emerged as a promising therapeutic strategy for addressing related diseases.

AREAS COVERED

This review offers a comprehensive summary of the progress in discovering STAT3 inhibitors, with a focus on their structural diversity and structure-activity relationships as presented in patent literature from 2022 to the present.

EXPERT OPINION

Over the past decades, significant progress has transformed STAT3 into a target of interest for drug development. Despite these advances, no STAT3-targeting drugs have successfully progressed through late-phase clinical trials, largely due to challenges such as limited selectivity and undesirable side effects. These obstacles highlight the inherent complexity of developing safe and effective STAT3 inhibitors. Nevertheless, STAT3 remains a highly promising therapeutic target, and ongoing advancements in this field hold the potential to unlock novel strategies for addressing STAT3-related diseases.

JAK-STAT pathway, type I/II cytokines, and new potential therapeutic strategy for autoimmune bullous diseases: update on pemphigus vulgaris and bullous pemphigoid

Autoimmune Bullous Diseases (AIBDs), characterized by the formation of blisters due to autoantibodies targeting structural proteins, pose significant therapeutic challenges. Current treatments, often involving glucocorticoids or traditional immunosuppressants, are limited by their non-specificity and side effects. Cytokines play a pivotal role in AIBDs pathogenesis by driving inflammation and immune responses. The JAK-STAT pathway is central to the biological effects of various type I and II cytokines, making it an attractive therapeutic target. Preliminary reports suggest that JAK inhibitors may be a promising approach in PV and BP, but further clinical validation is required. In AIBDs, particularly bullous pemphigoid (BP) and pemphigus vulgaris (PV), JAK inhibitors have shown promise in modulating pathogenic cytokine signaling. However, the safety and selectivity of JAK inhibitors remain critical considerations, with the potential for adverse effects and the need for tailored treatment strategies. This review explores the role of cytokines and the JAK-STAT pathway in BP and PV, evaluating the therapeutic potential and challenges associated with JAK inhibitors in managing these complex disorders.

STAT3/TGFBI signaling promotes the temozolomide resistance of glioblastoma through upregulating glycolysis by inducing cellular senescence

Glioblastoma (GBM) is the most lethal type of brain tumor. Recent studies have indicated that cellular senescence-targeted therapy is a promising approach for cancer treatment. However, the underlying mechanisms remain to be clarified. In this study, 101 unique combinations of 10 machine learning algorithms were used to construct prognostic models based on cellular senescence-related genes (CSRGs). We developed the CSRG signature (CSRGS) using machine learning models that exhibited optimal performance. GBM samples were stratified into high- and low-CSRGS groups based on CSRGS scores. Patients in the high-CSRGS group exhibited a worse prognosis, higher immune infiltration, and increased sensitivity to immune checkpoint blockade therapy. Furthermore, senescence-related pathways were significantly correlated with glycolysis, indicating upregulated glycolytic metabolism in senescent GBM cells. We identified TGFBI as a key regulator that played vital roles in both glycolysis and cellular senescence in GBM. TGFBI was overexpressed in GBM samples compared to normal brain tissues, and its knockdown via shRNA inhibited cellular senescence, glycolysis, and temozolomide resistance. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays confirmed that TGFBI is a direct STAT3 target and is required for the STAT3-induced promotion of cellular senescence, glycolysis, and drug resistance. The STAT3-TGFBI axis could be a potential target for senescence-targeted GBM therapy.

o8G-modified circKIAA1797 promotes lung cancer development by inhibiting cuproptosis

BACKGROUND

Lung cancer is a serious threat to human life and health, but effective screening and treatment methods are lacking. Circular RNAs (circRNAs) have important biological functions and are closely related to tumour development. Some studies have shown that the 8-oxo-7,8-dihydroguanosine (o8G) modification plays a key role in the disease process, but the effect of the o8G modification on circRNAs has not been elucidated. Moreover, cuproptosis is a novel mode of cell death in which copper ions directly promote protein aggregation and the disruption of cellular metabolic pathways. The present study revealed that the o8G modification of circKIAA1797 occurs and promotes lung cancer development by inhibiting cuproptosis, which provides new perspectives for epitranscriptomic studies and the development of novel therapeutic approaches for lung cancer.

METHODS

circRNA differential expression profiles in lung cancer were revealed via RNA high-throughput sequencing, and circKIAA1797 expression in lung cancer cell lines and tissues was detected using qPCR. Experiments such as o8G RNA immunoprecipitation (o8G RIP) and crosslinking immunoprecipitation (CLIP) were performed to explore the presence of o8G on circKIAA1797. The regulation of circKIAA1797 by the o8G reader Y-box binding protein 1 (YBX1) was explored using nuclear-cytoplasmic fractionation, actinomycin D (Act D) stability experiments and other experiments. circKIAA1797 silencing and overexpression systems were constructed for in vivo and in vitro experiments to study the role of circKIAA1797 in lung cancer development. Tagged RNA affinity purification (TRAP), RNA immunoprecipitation (RIP), coimmunoprecipitation (Co-IP), and immunofluorescence (IF) staining were subsequently conducted to reveal the molecular mechanism by which circKIAA1797 regulates cuproptosis and promotes lung cancer development.

RESULTS

This study is the first to reveal the presence of o8G on circKIAA1797 and that YBX1 is a reader that recognises ROS-induced circKIAA1797 o8G modifications and increases the stability and cytoplasmic expression of circKIAA1797. circKIAA1797, which is associated with the tumour stage and prognosis, has been shown to significantly promote the biological function of lung cancer development both in vivo and in vitro. This study revealed that circKIAA1797 inhibits intracellular cuproptosis by binding to the ferredoxin 1 (FDX1) mRNA, decreasing FDX1 mRNA stability, inhibiting FDX1 expression, and binding to the signal transducer and activator of transcription 1 (STAT1) protein and inhibiting lipoyltransferase 1 (LIPT1) transcription; moreover, circKIAA1797 promotes the closure of the mitochondrial permeability transition pore (mPTP), inhibits cuproptosis, and ultimately promotes lung cancer development.

CONCLUSIONS

This study revealed the presence of the o8G modification in circKIAA1797, which plays an important role in the development of lung cancer. circKIAA1797 can inhibit cuproptosis by inhibiting key cuproptosis proteins and promoting mPTP closure, ultimately promoting the development of lung cancer. This study provides not only a new theoretical basis for an in-depth understanding of the molecular mechanisms of lung cancer development but also a potential target for lung cancer treatment.

Discovery of benzethonium chloride as a potent STAT3 inhibitor for the treatment of HNSCC

Head and neck squamous cell carcinoma (HNSCC) is a prevalent malignancy with high mortality, and effective treatment strategies remain limited. This study investigated the effects of benzethonium chloride (BZN), an FDA-approved anti-infective agent, on HNSCC cell lines and its underlying mechanisms. BZN significantly inhibited the proliferation of HNSCC cell lines CAL27 and FaDu and induced apoptosis in both cell lines in vitro. In a subcutaneous tumor model, BZN markedly suppressed tumor growth in the mouse HNSCC cell line MOC1. Mechanistically, BZN may directly bind to the SH2 domain of STAT3, inhibit its dimerization, prevent the nuclear translocation of phosphorylated STAT3 (p-STAT3), downregulate the expression of the downstream protein MCL-1, and induce mitochondrial-mediated apoptosis in FaDu and CAL27 cells. These findings highlight BZN as a potential therapeutic agent for HNSCC, offering a novel approach to improve treatment outcomes in clinical settings.

STAT3 Signaling Pathway in Health and Disease

Signal transducer and activator of transcription 3 (STAT3) is a critical transcription factor involved in multiple physiological and pathological processes. While STAT3 plays an essential role in homeostasis, its persistent activation has been implicated in the pathogenesis of various diseases, particularly cancer, bone-related diseases, autoimmune disorders, inflammatory diseases, cardiovascular diseases, and neurodegenerative conditions. The interleukin-6/Janus kinase (JAK)/STAT3 signaling axis is central to STAT3 activation, influencing tumor microenvironment remodeling, angiogenesis, immune evasion, and therapy resistance. Despite extensive research, the precise mechanisms underlying dysregulated STAT3 signaling in disease progression remain incompletely understood, and no United States Food and Drug Administration (USFDA)-approved direct STAT3 inhibitors currently exist. This review provides a comprehensive evaluation of STAT3's role in health and disease, emphasizing its involvement in cancer stem cell maintenance, metastasis, inflammation, and drug resistance. We systematically discuss therapeutic strategies, including JAK inhibitors (tofacitinib, ruxolitinib), Src Homology 2 domain inhibitors (S3I-201, STATTIC), antisense oligonucleotides (AZD9150), and nanomedicine-based drug delivery systems, which enhance specificity and bioavailability while reducing toxicity. By integrating molecular mechanisms, disease pathology, and emerging therapeutic interventions, this review fills a critical knowledge gap in STAT3-targeted therapy. Our insights into STAT3 signaling crosstalk, epigenetic regulation, and resistance mechanisms offer a foundation for developing next-generation STAT3 inhibitors with greater clinical efficacy and translational potential.

Decoy-PROTAC for specific degradation of "Undruggable" STAT3 transcription factor

Signal transducer and activator of transcription 3 (STAT3) is widely recognized as an attractive target for cancer therapy due to its significant role in the initiation and progression of tumorigenesis. However, existing STAT3 inhibitors have suffered from drawbacks including poor efficacy, limited specificity, and undesirable off-target effects, due to the challenging nature of identifying active sites or allosteric regulatory pockets on STAT3 amenable to small-molecule inhibition. In response to these obstacles, we utilize the innovative proteolysis targeting chimera (PROTAC) technology to create a highly specific decoy-targeted protein degradation system for STAT3 protein, termed D-PROTAC. This system fuses DNA decoy that targets STAT3 with an E3 ligase ligand, utilizing a click chemistry approach. Experimental results demonstrate that D-PROTAC efficiently mediates the degradation of the STAT3 protein across various cancer cell types, leading to the downregulation of crucial downstream STAT3 targets, inhibiting tumor cell growth, triggering cell cycle arrest and apoptosis, and suppressing tumor immune evasion. Furthermore, D-PROTAC is capable of achieving significant tumor suppression in xenograft models. Overall, our research validates that D-PROTAC can successfully target and eliminate the "undruggable" STAT3, showcasing specificity and potent antitumor effects. This strategy will suggest a promising avenue for the development of targeted therapies against the critical functions of STAT3 in human cancers and potentially other diseases.

Tumor Cell-Expressed Herpesvirus Entry Mediator Regulates Proliferation and Adaptive Immunity in Ovarian Cancer

BACKGROUND

Ovarian cancer (OvCa) is a prevalent gynecological malignancy with an increasing incidence and high mortality rate. Although the role of the herpesvirus entry mediator (HVEM), encoded by the TNFRSF14 gene, is currently considered pivotal in various types of cancer, the regulation of tumor cell-expressed HVEM in OvCa remains inadequately understood.

METHODS

Specimens were used to detect HVEM expression via quantitative RT-PCR and flow cytometry. The proliferation of the murine OvCa cell line ID8 was determined using the Cell Counting Kit-8, colony formation, and EdU staining assays. The immune constituents within the ascites fluid and spleen of tumor-bearing mice were analyzed by flow cytometry. Bioinformatics analysis was performed to explore cytokines, chemokines, and signaling pathways regulated by HVEM, and differential expression levels were confirmed via quantitative RT-PCR and western blot analysis.

RESULTS

Herein, we identified a significant upregulation of HVEM in OvCa tissues compared with that in benign tissues and observed dominant expression of HVEM in CD45⁻EpCAM⁺ subsets in OvCa specimens. Tumor cell-expressed HVEM was found to promote OvCa cell proliferation by partly activating spliced X-box-binding protein 1 (XBP1s)-c-Myc signaling. In mouse models, knockdown of Tnfrsf14 in ID8 cells alleviated OvCa progression and specifically affected the frequency and function of T cells in the ascites fluid and spleen. In addition, tumor cell-expressed HVEM altered chemokine expression (CXCL1/9/10/11 and CCL2/4/5) and STAT signal activation (STAT5 and STAT6) in ID8 cells.

CONCLUSION

This study investigated the effects of HVEM on OvCa and validated its potential as a therapeutic marker for treating OvCa.

Targeting STAT3 for Cancer Therapy: Focusing on Y705, S727, or Dual Inhibition?

BACKGROUND/OBJECTIVES

Signal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor that is strongly implicated in various cancers. In its canonical signaling pathway, Janus kinases (JAKs) phosphorylate STAT3 at the Y705 residue in response to cytokines or growth factors, with pY705 serving as a key marker of STAT3 oncogenic activity. Elevated pY705 levels correlate with poor prognosis, and numerous small-molecule inhibitors have been developed to block this phosphorylation site. More recently, phosphorylation at the S727 residue (pS727) has emerged as a critical contributor to STAT3-mediated oncogenesis, particularly due to its role in mitochondrial translocation. Evidence suggests that pS727 may even surpass pY705 in driving oncogenic activity. These findings prompt an important question: Which residue should be prioritized for effective STAT3 inhibition in cancer therapy?

METHODS

This review compiles and critically analyzes the current literature on STAT3 inhibitors targeting pY705 and/or pS727, evaluating their therapeutic efficacy in vitro, in vivo, and in clinical trials. We assess the unique effects of targeting each residue on downstream signaling, toxicity, and clinical outcomes.

RESULTS

Our analysis indicates that inhibitors targeting both pY705 and pS727 achieve the greatest therapeutic effectiveness. However, pS727 targeting is associated with higher toxicity risks.

CONCLUSIONS

Comprehensive evaluation of STAT3 inhibitors underscores the importance of targeting pY705 for maximum therapeutic benefit. The analysis also shows that co-targeting pS727 may increase overall efficacy. However, pS727 inhibition should be approached with lower affinity to minimize toxicity and enhance the clinical feasibility of dual-targeting strategies.

circ0066187 promotes pulmonary fibrogenesis through targeting STAT3-mediated metabolism signal pathway

Idiopathic pulmonary fibrosis (IPF) is a chronic and progressive interstitial pneumonia, with increasing incidence and prevalence. One of the cellular characteristics is the differentiation of fibroblasts to myofibroblasts. However, the metabolic-related signaling pathway regulated by circular RNAs (circRNAs) during this process remains unclear. Here, we demonstrated that circ0066187 promoted fibroblast-to-myofibroblast differentiation by metabolic-related signaling pathway. Mechanism analysis research identified that circ0066187 directly targeted signal transducer and activator of transcription 3 (STAT3)-mediated metabolism signal pathway to enhance fibroblast-to-myofibroblast differentiation by sponging miR-29b-2-5p, resulting in pulmonary fibrosis. Integrative multi-omics analysis of metabolomics and proteomics revealed three pathways co-enriched in proteomics and metabolomics, namely, Protein digestion and absorption, PI3K-Akt signaling pathway, and FoxO signaling pathway. In these three signaling pathways, seven differentially expressed metabolites such as L-glutamine, L-proline, adenosine monophosphate (AMP), L-arginine, L-phenylalanine, L-lysine and L-tryptophan, and six differentially expressed proteins containing dipeptidyl peptidase-4 (DPP4), cyclin D1 (CCND1), cyclin-dependent kinase 2 (CDK2), fibroblast growth factor 2 (FGF2), collagen type VI alpha 1 (COL6A1) and superoxide dismutase 2 (SOD2) were co-enriched. Gain-and loss-of-function studies and rescue experiments were performed to verify that circ0066187 promoted STAT3 expression by inhibiting miR-29b-2-5p expression to control the above metabolites and proteins. As a result, these metabolites and proteins provided the material basis and energy requirements for the progression of pulmonary fibrosis. In conclusion, circ0066187 can function as a profibrotic metabolism-related factor, and interference with circ0066187 can prevent pulmonary fibrosis. The finding supported that circ0066187 can be a metabolism-related therapeutic target for IPF treatment.

Advances in the study of CCT3 in malignant tumors: A review

Malignant tumors are among the leading causes of death worldwide, with their underlying mechanisms remaining largely unclear. Tumorigenesis is a complex process involving multiple factors, genes, and pathways. Tumor cells are characterized by abnormal proliferation, infiltration, invasion, and metastasis. Improving tumor diagnosis rates and identifying novel molecular therapeutic targets are of great significance for the advancement of modern medicine. Chaperonin containing TCP-1 subunit 3 (CCT3) is one of the subunits of the chaperonin containing TCP-1 complex, a molecular chaperone involved in protein folding and remodeling. CCT3 plays a crucial role in maintaining protein homeostasis, with key substrates including tubulin and actin. In recent years, CCT3 has been reported to be abnormally expressed in various cancers, correlating with prognosis and therapeutic outcomes. In this review, we summarize the basic structure and function of chaperonin containing TCP-1 complex and CCT3, and discuss the role of CCT3 in tumor development. Additionally, we explore its potential applications in cancer diagnosis and treatment.

l-[5-11C]Glutamine PET imaging noninvasively tracks dynamic responses of glutaminolysis in non-alcoholic steatohepatitis

Inhibiting glutamine metabolism has been proposed as a potential treatment strategy for improving non-alcoholic steatohepatitis (NASH). However, effective methods for assessing dynamic metabolic responses during interventions targeting glutaminolysis have not yet emerged. Here, we developed a positron emission tomography (PET) imaging platform using l-[5-11C]glutamine ([11C]Gln) and evaluated its efficacy in NASH mice undergoing metabolic therapy with bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl)ethyl sulfide (BPTES), a glutaminase 1 (GLS1) inhibitor that intervenes in the first and rate-limiting step of glutaminolysis. PET imaging with [11C]Gln effectively delineated the pharmacokinetics of l-glutamine, capturing its temporal-spatial pattern of action within the body. Furthermore, [11C]Gln PET imaging revealed a significant increase in hepatic uptake in methionine and choline deficient (MCD)-fed NASH mice, whereas systemic therapeutic interventions with BPTES reduced the hepatic avidity of [11C]Gln in MCD-fed mice. This reduction in [11C]Gln uptake correlated with a decrease in GLS1 burden and improvements in liver damage, indicating the efficacy of BPTES in mitigating NASH-related metabolic abnormalities. These results suggest that [11C]Gln PET imaging can serve as a noninvasive diagnostic platform for whole-body, real-time tracking of responses of glutaminolysis to GLS1 manipulation in NASH, and it may be a valuable tool for the clinical management of patients with NASH undergoing glutaminolysis-based metabolic therapy.

Transcription factors in the development and treatment of immune disorders

Immune function is highly controlled at the transcriptional level by the binding of transcription factors (TFs) to promoter and enhancer elements. Several TF families play major roles in immune gene expression, including NF-κB, STAT, IRF, AP-1, NRs, and NFAT, which trigger anti-pathogen responses, promote cell differentiation, and maintain immune system homeostasis. Aberrant expression, activation, or sequence of isoforms and variants of these TFs can result in autoimmune and inflammatory diseases as well as hematological and solid tumor cancers. For this reason, TFs have become attractive drug targets, even though most were previously deemed "undruggable" due to their lack of small molecule binding pockets and the presence of intrinsically disordered regions. However, several aspects of TF structure and function can be targeted for therapeutic intervention, such as ligand-binding domains, protein-protein interactions between TFs and with cofactors, TF-DNA binding, TF stability, upstream signaling pathways, and TF expression. In this review, we provide an overview of each of the important TF families, how they function in immunity, and some related diseases they are involved in. Additionally, we discuss the ways of targeting TFs with drugs along with recent research developments in these areas and their clinical applications, followed by the advantages and disadvantages of targeting TFs for the treatment of immune disorders.

Tumor Microenvironment-Responsive Nanoparticles Enhance IDO1 Blockade Immunotherapy by Remodeling Metabolic Immunosuppression

The clinical efficacy of immune checkpoint blockade (ICB) therapy is significantly compromised in the metabolically disordered tumor microenvironment (TME), posing a formidable challenge that cannot be ignored in current antitumor strategies. In this study, TME-responsive nanoparticles (HMP1G NPs) loaded with 1-methyltryptophan (1-MT; an indoleamine 2,3-dioxygenase 1 [IDO1] inhibitor,) and S-nitrosoglutathione (GSNO; a nitric oxide donor) is developed to enhance the therapeutic efficacy of 1-MT-mediated ICB. The HMP1G NPs responded to H+ and glutathione in the TME, releasing Mn2+, GSNO, and 1-MT. The released Mn2+ catalyzed the production of abundant reactive oxygen species and nitric oxide from hydrogen peroxide and GSNO, and the generated nitric oxide, synergistically with 1-MT, inhibited the accumulation of kynurenine mediated by IDO1 in the tumor. Mechanistically, HMP1G NPs downregulated tumor cell-derived IDO1 via the aryl hydrocarbon receptor/signal transducer and activator of transcription 3/interleukin signaling axis to improve kynurenine/tryptophan metabolism and immunosuppression. In a murine breast cancer model, treatment with HMP1G NPs elicited effective antitumor immunity and enhanced survival outcomes. This study highlights a novel nano-platform that simultaneously improves metabolism and enhances ICB efficacy to achieve a new and efficient antitumor strategy.

Minocycline Ameliorates Staphylococcus aureus-Induced Neuroinflammation and Anxiety-like Behaviors by Regulating the TLR2 and STAT3 Pathways in Microglia

Background: Anxiety disorders are the most common mental illnesses. S. aureus is a Gram-positive opportunistic pathogen most commonly associated with anxiety-like behaviors. Minocycline ameliorates Gram-negative bacterial LPS-induced anxiety-like behaviors by suppressing microglia activation. However, the effects of minocycline on anxiety-like behaviors caused by S. aureus infections have received little attention. In this study, we aimed to investigate the molecular mechanism and effect of minocycline on anxiety-like behaviors caused by S. aureus infection. Methods: BV2 and N9 microglial cells were treated in vitro. The effects of minocycline on lipoteichoic acid (LTA)-stimulated inflammatory responses, STAT3 activation, and GLS1 expression were assessed using Western blotting, and cytokine secretion was determined using an ELISA. A mouse model was used to evaluate the capacity of minocycline to ameliorate anxiety-like behaviors caused by S. aureus infection. Results: We found that ≥100 μmol/L of minocycline remarkably attenuated LTA-induced TLR2 signaling pathway activation and proinflammatory cytokine expression in microglial cells. Minocycline prevented LTA-stimulated STAT3 activation and GLS1 expression in vitro. LTA-induced TLR2, TNF-α, IL-6, and GLS1 expression was markedly reduced by the inhibition of STAT3 phosphorylation. Mice were pretreated with 50 mg/kg of minocycline, significantly attenuating microglial activation and neuroinflammation. Minocycline also effectively alleviated the anxiety-like behaviors induced by S. aureus infection. Conclusions: Our findings indicate that minocycline alleviates S. aureus infection-induced anxiety-like behaviors by suppressing microglia activation.

DNA Tetrahedron-Driven Multivalent Proteolysis-Targeting Chimeras: Enhancing Protein Degradation Efficiency and Tumor Targeting

Proteolysis-targeting chimeras (PROTACs) are dual-functional molecules composed of a protein of interest (POI) ligand and an E3 ligase ligand connected by a linker, which can recruit POI and E3 ligases simultaneously, thereby inducing the degradation of POI and showing great potential in disease treatment. A challenge in developing PROTACs is the design of linkers and the modification of ligands to establish a multifunctional platform that enhances degradation efficiency and antitumor activity. As a programmable and modifiable nanomaterial, DNA tetrahedron can precisely assemble and selectively recognize molecules and flexibly adjust the distance between molecules, making them ideal linkers. Herein, we developed a multivalent PROTAC based on a DNA tetrahedron, named AS-TD2-PRO. Using DNA tetrahedron as a linker, we combined modules targeting tumor cells, recognizing E3 ligases, and multiple POI together. We took the undruggable target protein signal transducer and activator of transcription 3 (STAT3), associated with the etiology and progression in a variety of malignant tumors, as an example in this study. AS-TD2-PRO with two STAT3 recognition modules demonstrated good potential in enhancing tumor-specific targeting and degradation efficiency compared to traditional bivalent PROTACs. Furthermore, in a mouse tumor model, the superior therapeutic activity of AS-TD2-PRO was observed. Overall, DNA tetrahedron-driven multivalent PROTACs both serve as a proof of principle for multifunctional PROTAC design and introduce a promising avenue for cancer treatment strategies.

Resveratrol-driven macrophage polarization: unveiling mechanisms and therapeutic potential

Resveratrol, a polyphenolic compound known for its diverse biological activities, has demonstrated multiple pharmacological effects, including anti-inflammatory, anti-aging, anti-diabetic, anti-cancer, and cardiovascular protective properties. Recent studies suggest that these effects are partly mediated through the regulation of macrophage polarization, wherein macrophages differentiate into pro-inflammatory M1 or anti-inflammatory M2 phenotypes. Our review highlights how resveratrol modulates macrophage polarization through various signaling pathways to achieve therapeutic effects. For example, resveratrol can activate the senescence-associated secretory phenotype (SASP) pathway and inhibit the signal transducer and activator of transcription (STAT3) and sphingosine-1-phosphate (S1P)-YAP signaling axes, promoting M1 polarization or suppressing M2 polarization, thereby inhibiting tumor growth. Conversely, it can promote M2 polarization or suppress M1 polarization by inhibiting the NF-κB signaling pathway or activating the PI3K/Akt and AMP-activated protein kinase (AMPK) pathways, thus alleviating inflammatory responses. Notably, the effect of resveratrol on macrophage polarization is concentration-dependent; moderate concentrations tend to promote M1 polarization, while higher concentrations may favor M2 polarization. This concentration dependence offers new perspectives for clinical treatment but also underscores the necessity for precise dosage control when using resveratrol. In summary, resveratrol exhibits significant potential in regulating macrophage polarization and treating related diseases.

The immune checkpoint molecule B7-H4 regulates β-cell mass and insulin secretion by modulating cholesterol metabolism through Stat5 signalling

OBJECTIVE

B7-H4 (B7S1, B7x, VTCN1) is an important immune checkpoint molecule that maintains immune homeostasis and is also expressed in pancreatic β cells. The polymorphism of B7-H4 influences the prevalence of Type 2 diabetes (T2D), suggesting a potential role of B7-H4 in the physiological function of pancreatic β cells and the pathogenesis of T2D.

METHODS

β-cell-specific B7-H4 knockout mice (B7-H4 cKO mice) and their wild-type littermates were used to investigate the in vivo effects of B7-H4 on pancreatic β-cell morphology and function. AAV2/8-ins2-B7H4 and a control virus were infused via the pancreatic intraduct into high-fat diet (HFD)-treated mice to elucidate the therapeutic effect of B7-H4. RNA sequencing was conducted on primary islets. A Luminex assay was used to quantify cytokine changes in B7-H4 cKO mice. Electron microscopy imaging was used to observe insulin secretory vesicles in pancreatic β cells.

RESULTS

Lesion of B7-H4 in β cells results in glucose intolerance due to reduced β-cell mass and deficient insulin secretion, whereas overexpression of B7-H4 in β cells ameliorates glucose intolerance in HFD-fed mice. Mechanistically, B7-H4 deficiency activates signal transducer and activator of transcription 5 (Stat5) signalling, which inhibits the expression of apolipoprotein F (Apof), leading to reduced cholesterol efflux and accumulated cholesterol in β cells, thereby impairing insulin processing and secretion. Overexpression of Apof in β cells or intraperitoneal injection of a Stat5 inhibitor reverses the metabolic phenotype and insulin secretion deficiency in B7-H4 cKO mice.

CONCLUSION

Our study demonstrated that B7-H4 plays an important role in regulating β-cell mass and insulin secretion, which may shed new light on the development of novel strategies for T2D treatment.

Icariin promoted ferroptosis by activating mitochondrial dysfunction to inhibit colorectal cancer and synergistically enhanced the efficacy of PD-1 inhibitors

BACKGROUND

A controlled type of cell death called ferroptosis is linked to increased reactive oxygen species (ROS), lipid peroxidation, and iron buildup. Furthermore, evidence indicates that ferroptosis may act as an immunogenic form of cell death with potential physiological functions in tumors and immunosuppression. Inducing ferroptosis in tumor cells may have the potential to complement cancer immunotherapy strategies. The development of colorectal cancer (CRC) and the poor efficacy of immunotherapy are associated with the crosstalk of cellular ferroptosis. Currently, Icariin (ICA), the main bioactive component extracted from Epimedium, has been shown to inhibit a variety of cancers. However, the specific role and potential mechanism of ICA in regulating ferroptosis in CRC remains unclear.

PURPOSE

The aim of this investigation was to clarify the mechanism underlying the anti-CRC cancer properties of ICA and how it induces ferroptosis to enhance immunotherapy.

METHODS

To evaluate cell viability, the Cell Counting Kit-8 (CCK-8) test was utilized. The transwell test and the wound healing assay were used to assess cell migration. A subcutaneous graft tumor model was constructed with C57BL/6 mice using MC38 colorectal cancer cell lines. The inhibitory effect of ICA on CRC, ferroptosis level and immunomodulatory effects were detected by serum biochemical assay, cytokine assay, hematoxylin-eosin (H&E) staining, immunofluorescence staining, CyTOF mass spectrometry flow screening and Western blotting. Western blotting, proteomics, molecular docking and microscale thermophoresis (MST) were used to forecast and confirm ICA's binding and interaction with HMGA2, STAT3, and HIF-1α. Moreover, the levels of lipid peroxidation and ferroptosis were assessed through the use of the C11-BODIPY fluorescent probe, the FerroOrange fluorescent probe, the iron level, the malondialdehyde (MDA) and reduced glutathione (GSH) assay kit, and Western blotting analysis. To assess alterations in mitochondrial structure and membrane potential, transmission electron microscopy (TEM) and JC-1 immunofluorescence were employed.

RESULTS

It was demonstrated in the current study that ICA treatment inhibits CRC and enhances anti-PD-1 therapy efficacy by inciting ferroptosis. As shown in vitro, ICA inhibits CRC cell proliferation, migration, and apoptosis. As demonstrated in vivo, ICA has a dose-dependent tumor suppressor effect when combined with anti-PD-1, it can significantly inhibit tumor growth, increase the expression of serum TNF-α, IFN-γ, and granzyme B, and promote CD69+CD8+ T, CD69+CD8+Tem, CD69+CD8+Teff, TCRβ+CD8+ T, TCRβ+CD8+ T, TCRβ+CD8+Tem, TCRβ+CD8+Teff. The inhibitory effect of ICA on CRC was associated with the binding of HMGA2, STAT3, and HIF-1α proteins, which inhibited CRC by increasing the levels of reactive oxygen species (ROS) and malondialdehyde (MDA), promoting the accumulation of iron (Fe2+), depletion of reduced glutathione (GSH), inhibiting SLC7A11 and GPX4 expressions, thereby inducing ferroptosis in CRC. As a consequence of ICA-induced ferroptosis, mitochondria are dysfunctional, with increased ROS production, membrane potential depolarization (MMP), and ATP production reduced. This process can be efficiently reversed by the mitochondria-targeted antioxidant Mito-Q. It is noteworthy that the ferroptosis inhibitor liproxstatin-1 (lip-1), anti-CD8, and anti-IFN-γ exhibited a significant inhibitory effect on the level of ferroptosis and antitumor capacity of ICA combined with anti-PD-1. This finding suggests that the antitumor immunopotentiating effect of ICA on anti-PD-1 is dependent on the secretion of IFN-γ-induced ferroptosis of CRC cells by the CD8+ T cell.

CONCLUSION

Our study represents the inaugural demonstration of the mechanism whereby ICA exerts anti-CRC effects and synergistically enhances the efficacy of anti-PD-1, inducing mitochondrial damage and leading to ferroptosis. ICA promotes ferroptosis of CRC cells by inducing mitochondrial dysfunction, and ICA combined with anti-PD-1 significantly promotes CD69, TCRβ signalling, activates effector CD8+ T cells to secrete IFN-γ, and achieves immunopotentiation by promoting ferroptosis of CRC cells, thus inhibiting CRC development. This study is built upon existing research into the pharmacodynamic mechanisms of ICA in the context of CRC, and offers a novel therapeutic approach in addressing the issue of CRC immunotherapy potentiation.

The role of acetylation and deacetylation in cancer metabolism

As a hallmark of cancer, metabolic reprogramming adjusts macromolecular synthesis, energy metabolism and redox homeostasis processes to adapt to and promote the complex biological processes of abnormal growth and proliferation. The complexity of metabolic reprogramming lies in its precise regulation by multiple levels and factors, including the interplay of multiple signalling pathways, precise regulation of transcription factors and dynamic adjustments in metabolic enzyme activity. In this complex regulatory network, acetylation and deacetylation, which are important post-translational modifications, regulate key molecules and processes related to metabolic reprogramming by affecting protein function and stability. Dysregulation of acetylation and deacetylation may alter cancer cell metabolic patterns by affecting signalling pathways, transcription factors and metabolic enzyme activity related to metabolic reprogramming, increasing the susceptibility to rapid proliferation and survival. In this review, we focus on discussing how acetylation and deacetylation regulate cancer metabolism, thereby highlighting the central role of these post-translational modifications in metabolic reprogramming, and hoping to provide strong support for the development of novel cancer treatment strategies. KEY POINTS: Protein acetylation and deacetylation are key regulators of metabolic reprogramming in tumour cells. These modifications influence signalling pathways critical for tumour metabolism. They modulate the activity of transcription factors that drive gene expression changes. Metabolic enzymes are also affected, altering cellular metabolism to support tumour growth.

The structural influence of the oncogenic driver mutation N642H in the STAT5B SH2 domain

The point mutation N642H of the signal transducer and activator of transcription 5B (STAT5B) protein is associated with aggressive and drug-resistant forms of leukemia. This mutation is thought to promote cancer due to hyperactivation of STAT5B caused by increased stability of the active, parallel dimer state. However, the molecular mechanism leading to this stabilization is not well understood as there is currently no structure of the parallel dimer. To investigate the mutation's mechanism of action, we conducted extensive all-atom molecular dynamics simulations of multiple oligomeric forms of both STAT5B and STAT5BN642H, including a model for the parallel dimer. The N642H mutation directly affects the hydrogen bonding network within the phosphotyrosine (pY)-binding pocket of the parallel dimer, enhancing the pY-binding interaction. The simulations indicate that apo STAT5B is highly flexible, exploring a diverse conformational space. In contrast, apo STAT5BN642H accesses two distinct conformational states, one of which resembles the conformation of the parallel dimer. The simulation predictions of the effects of the mutation on structure and dynamics are supported by the results of hydrogen-deuterium exchange (HDX) mass spectrometry measurements carried out on STAT5B and STAT5BN642H in which a phosphopeptide was used to mimic the effects of parallel dimerization on the SH2 domain. The molecular-level information uncovered in this work contributes to our understanding of STAT5B hyperactivation by the N642H mutation and could help pave the way for novel therapeutic strategies targeting this mutation.

Design, synthesis, and biological evaluation of novel 5,7,4'-trimethoxyflavone sulfonamide-based derivatives as highly potent inhibitors of LRPPRC/STAT3/CDK1

Leucine-rich pentatricopeptide repeat-containing protein (LRPPRC), signal transducer and activator of transcription 3 (STAT3), and cyclin-dependent kinase 1 (CDK1) are promising therapeutic targets for cancer treatment. However, there is a lack of effective inhibitors of LRPPRC, STAT3, and CDK1 in clinic. Our previous study has proved that 5,7,4'-Trimethoxyflavone (TMF) is a novel inhibitor of LRPPRC/STAT3/CDK1. However, the extraction rate of TMF from Tangerine Peel is quite low, and the doses of TMF in cells and mice are rather high. Herein, structural modifications of TMF have led to two series of TMF derivatives including sulfonamide substituted at 3'-position (7a-m) and 3',8-position (11a-m). Among all compounds, 7e, 7k, 11e, and 11g exhibited as effective, broad-spectrum, and potent anticancer agents in vitro. Moreover, 7e, 7k, 11e, and 11g showed better antitumor effects than TMF and clinical used chemotherapy drug capecitabine in vivo with no obvious toxicity. Mechanism studies showed that 11g could bind to LRPPRC, STAT3, and CDK1 to disassociate the LRPPRC-JAK2-STAT3 and JAK2-STAT3-CDK1 complexes, resulting in suppression of JAK2/STAT3 signaling pathway. These findings suggest that 11g may serve as a leading compound for cancer therapy as a triple-target (LRPPRC, STAT3, and CDK1) inhibitor.

Understanding the role of TNFR2 signaling in the tumor microenvironment of breast cancer

Breast cancer (BC) is the most frequently diagnosed malignancy among women. It is characterized by a high level of heterogeneity that emerges from the interaction of several cellular and soluble components in the tumor microenvironment (TME), such as cytokines, tumor cells and tumor-associated immune cells. Tumor necrosis factor (TNF) receptor 2 (TNFR2) appears to play a significant role in microenvironmental regulation, tumor progression, immune evasion, drug resistance, and metastasis of many types of cancer, including BC. However, the significance of TNFR2 in BC biology is not fully understood. This review provides an overview of TNFR2 biology, detailing its activation and its interactions with important signaling pathways in the TME (e.g., NF-κB, MAPK, and PI3K/Akt pathways). We discuss potential therapeutic strategies targeting TNFR2, with the aim of enhancing the antitumor immune response to BC. This review provides insights into role of TNFR2 as a major immune checkpoint for the future treatment of patients with BC.

STAT3 drives the expression of HIF1alpha in cancer cells through a novel super-enhancer

Aerobic glycolysis is one of the major hallmarks of malignant tumors. This metabolic reprogramming benefits the rapid proliferation of cancer cells, facilitates the formation of tumor microenvironment to support their growth and survival, and impairs the efficacy of various tumor therapies. Therefore, the elucidation of the mechanisms driving aerobic glycolysis in tumors represents a pivotal breakthrough in developing therapeutic strategies for solid tumors. HIF1α serves as a central regulator of aerobic glycolysis with elevated mRNA and protein expression across multiple tumor types. However, the mechanisms contributing to this upregulation remain elusive. This study reports the identification of a novel HIF1α super enhancer (HSE) in multiple cancer cells using bioinformatics analysis, chromosome conformation capture (3C), chromatin immunoprecipitation (ChIP), and CRISPR/Cas9 genome editing techniques. Deletion of HSE in cancer cells significantly reduces the expression of HIF1α, glycolysis, cell proliferation, colony and tumor formation ability, confirming the role of HSE as the enhancer of HIF1α in cancer cells. Particularly, we demonstrated that STAT3 promotes the expression of HIF1α by binding to HSE. The discovery of HSE will help elucidate the pathways driving tumor aerobic glycolysis, offering new therapeutic targets and potentially resolving the bottleneck in solid tumor treatment.

Fatty acid metabolism affects hepatocellular carcinoma progression via the PPAR-γ signaling pathway and fatty acid β-oxidation

PURPOSE

This study aimed to explore novel targets for hepatocellular carcinoma (HCC) treatment by investigating the role of fatty acid metabolism.

METHODS

RNA-seq and clinical data of HCC were obtained from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Bioinformatic analyses were employed to identify differentially expressed genes (DEGs) related to prognosis. A signature was then constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression to classify HCC patients from the TCGA database into low-risk and high-risk groups. The predictive performance of the signature was evaluated through principal components analysis (PCA), Kaplan Meier (KM) survival analysis, receiver operating characteristics (ROC) curves, nomogram, genetic mutations, drug sensitivity analysis, immunological correlation analysis, and enrichment analysis. Single-cell maps were constructed to illustrate the distribution of core genes. Immunohistochemistry (IHC), quantitative real-time PCR (qRT-PCR), and western blot were employed to verify the expression of core genes. The function of one core gene was validated through a series of in vitro assays, including cell viability, colony formation, wound healing, trans-well migration, and invasion assays. The results were analyzed in the context of relevant signaling pathways.

RESULTS

Bioinformatic analyses identified 15 FAMGs that were related to prognosis. A 4-gene signature was constructed, and patients were divided into high- and low-risk groups according to the signature. The high-risk group exhibited a poorer prognosis compared to the low-risk group in both the training (P < 0.001) and validation (P = 0.020) sets. Furthermore, the risk score was identified as an independent predictor of OS (P < 0.001, HR = 8.005). The incorporation of the risk score and clinicopathologic features into a nomogram enabled the effective prediction of patient prognosis. The model was able to effectively predict the immune microenvironment, drug sensitivity to chemotherapy, and gene mutation for each group. Single-cell maps demonstrated that FAMGs in the model were distributed in tumor cells. Enrichment analyses revealed that the cell cycle, fatty acid β oxidation and PPAR signaling pathways were the most significant pathways. Among the four key prognostically related FAMGs, Spermine Synthase (SMS) was selected and validated as a potential oncogene affecting cell cycle, PPAR-γ signaling pathway and fatty acid β oxidation in HCC.

CONCLUSIONS

The risk characteristics based on FAMGs could serve as independent prognostic indicators for predicting HCC prognosis and could also serve as evaluation criteria for gene mutations, immunity, and chemotherapy drug therapy in HCC patients. Meanwhile, targeted fatty acid metabolism could be used to treat HCC through related signaling pathways.

Association Between Phosphorylated AXL Expression and Survival in Patients with Gastric Cancer

Background: Gastric cancer (GC) is a leading cause of cancer-related mortality, particularly in East Asia. Despite treatment advances, the prognosis remains poor owing to late diagnosis and high metastatic potential. Phosphorylated AXL (pAXL), a receptor tyrosine kinase, promotes cancer progression, including epithelial-mesenchymal transition (EMT), tumor growth, and metastasis. In this study, we aimed to investigate the relationship between pAXL expression and prognosis in patients with GC, focusing on survival outcomes and other biomarkers such as fibronectin and phosphorylated AKT (pAkt). Methods: Immunohistochemistry was performed to assess the expression of pAXL, fibronectin, and pAkt in 188 GC specimens collected between 2000 and 2013. H-scores were calculated based on staining intensity and percentage. The association between pAXL expression and patient outcomes was assessed using Kaplan-Meier survival analysis and multivariate logistic regression. Results: Higher pAXL expression was significantly associated with improved survival, particularly in male patients. pAXL expression positively correlated with fibronectin and pAkt upregulation, suggesting its role in promoting tumor invasion and EMT. Multivariate analysis identified pAXL, fibronectin, and pAkt as significant prognostic indicators, whereas other factors such as age, tumor grade, and tumor size were not statistically significant. Conclusions: This study identified pAXL as a valuable prognostic marker in GC, with higher expression levels associated with better survival outcomes, particularly in male patients. pAXL enhanced the invasive potential of GC cells through fibronectin and pAkt regulation, making it a promising therapeutic target. Further research is needed to explore the potential of pAXL-targeted therapies and better understand their role in cancer progression and treatment response.

MiR-301b-3p promotes breast cancer development through inhibiting the expression of transforming growth factor-beta receptor 2

Background

Breast cancer (BC) is a serious health threat to the patients. The present work explored the mechanism of miR-301b-3p and transforming growth factor-beta receptor 2 (TGFBR2 ) in affecting BC progression.

Methods

The miR-301b-3p-inhibitor and si-TGFBR2 solution were added to the DEME/F12 medium to culture the BC and normal breast epithelial cell lines to prepare negative control, miR-301b-3p-IN and miR-301b-3p-IN+si-TGFBR2 in the two types of cell lines. The relative expression of target genes and the interference effect were analyzed by quantitative real-time PCR (qRT- PCR). Cell viability was detected applying cell counting kit-8 (CCK-8) assay. Transwell and wound healing assay were conducted to evaluate the invasion and migration of BC cells after miR-301b-3p inhibition. Additionally, cell apoptosis and the expression STAT protein were measured by flow cytometry and Western blot, respectively.

Results

The qRT-PCR results showed that miR-301b-3p were high-expressed but the level of TGFBR2 was significantly inhibited in BC cells. The miR-301b-3p-inhibitor significantly downregulated the expression of miR-301b-3p and upregulated that of TGFBR2. Meanwhile, inhibition of miR-301b-3p suppressed the cell viability, invasion, and migration of BC cells, which, however, were restored by the inhibition of TGFBR2. MiR-301b-3p conferred anti-apoptosis ability to BC cells, while TGFBR2 promoted apoptosis of BC cells through producing an antagonistic effect with miR-301b-3p. We found that miR-301b-3p played a crucial role in the phosphorylation of STAT1 and STAT3 to promote BC progression.

Conclusion

The present findings demonstrated that miR-301b-3p played a crucial role in promoting BC cell growth, invasion and migration and anti-apoptosis, and that targeting TGFBR2 could inhibit the tumor-promoting effect of miR-301b-3p.