DUSP4 promotes esophageal squamous cell carcinoma progression by dephosphorylating HSP90β

GPR87 Promotes Angiogenesis in Esophageal Squamous Cell Carcinoma via VEGFA Regulation

The role and underlying mechanisms of G protein-coupled receptor 87 (GPR87) in esophageal squamous cell carcinoma (ESCC) remain unclear, despite its established oncogenic functions in other malignancies. This study examined the expression of GPR87 and its association with survival rate in ESCC using online databases. The expression of GPR87 in ESCC tissues was identified using immunohistochemistry, and a correlation analysis was carried out using ki-67 data. ESCC cells were transfected with GPR87 knockdown or overexpression plasmids, followed by functional assays such as, CCK-8 for cell viability, colony formation for proliferation, wound healing for migration, Transwell for invasion, and tube formation for angiogenesis. Western blot analysis was used to assess STAT3 phosphorylation and VEGFA expression. Additionally, a xenograft tumor model was established to investigate the effect of GPR87 on tumor growth in vivo. The findings demonstrated that GPR87 was highly expressed in ESCC tissues and its overexpression was associated with a poor patient survival. Transfection with a GPR87 overexpression plasmid increases the cell viability, invasion, proliferation, and angiogenesis of ESCC cells, while transfection with sh-GPR87 reversed these effects. Additionally, GPR87 controlled VEGFA expression levels by promoting STAT3 phosphorylation. Rescue trials further verified that GPR87 promotes the growth of ESCC by modulating STAT3. Moreover, in vivo studies validated that GPR87 knockdown suppressed tumor growth. In conclusion, the findings highlight GPR87 as a key regulator of VEGFA expression via STAT3 activation, contributing to ESCC malignancy. Targeting GPR87 may provide a potential therapeutic strategy for ESCC.

TCPTP inhibition as a novel therapeutic strategy for esophageal squamous cell carcinoma: discovery and efficacy of COH29

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor that poses a serious threat to human health and is often associated with poor prognosis. Therefore, it is urgent to explore new therapeutic strategies to improve the survival rate of patients with ESCC. T cell protein tyrosine phosphatase (TCPTP) has been reported as a complicated factor in cancer. In this study, we found that TCPTP was highly expressed in ESCC tissues and suppression of TCPTP can effectively inhibit the proliferation of ESCC cells in vitro and in vivo. To identify potential TCPTP inhibitors, we employed a comprehensive research approach encompassing virtual screening, pull down assay, and cellular thermal shift assay. This led to the discovery of two promising candidates: COH29 and gallocatechin gallate (GCG). Both compounds showed inhibitory effects on ESCC cell proliferation, with COH29 displaying superior efficacy. Further enzyme kinetics assay and molecular dynamics simulations confirmed COH29's unique ability to bind to both the substrate and allosteric sites of TCPTP, making it a promising lead compound for future inhibitor development. Flow cytometry analysis revealed that COH29 treatment caused cell cycle arrest in the G1 phase in ESCC cells. In vivo studies further validated COH29's robust growth suppression of ESCC, highlighting its potential as a therapeutic agent.

The transcription factor PITX1 cooperates with super-enhancers to regulate the expression of DUSP4 and inhibit pyroptosis in pulmonary artery smooth muscle cells

BACKGROUND

Pulmonary hypertension (PH) is a highly fatal pathophysiological syndrome. The group 1 pulmonary arterial hypertension (PAH) is characterized by acute pulmonary vasoconstriction and chronic vascular remodeling caused by hyperplasia and hypertrophy of pulmonary artery smooth muscle cells (PASMCs) and chronic inflammation. Pyroptosis is an inflammatory mode of cell death that is regulated by super-enhancers (SEs) and occurs in the setting of tumors and cardiovascular diseases. However, whether SEs are involved in the pathological process of pyroptosis in PAH and the specific mechanism involved remain unclear.

METHODS

Here, we identified the SE target gene DUSP4 via ChIP-seq with an anti-H3K27ac antibody, and bioinformatics predictions revealed that the transcription factor PITX1 can bind to the promoter and SE sequences of DUSP4. The AAV5 vector was used to deliver shRNAs targeting PITX1 and DUSP4 to PASMCs.

RESULTS

PITX1 overexpression reversed the increase in right ventricular systolic pressure and pulmonary vascular remodeling, restored the PAAT/PAVTI ratio in hypoxic pulmonary hypertension (HPH, Group 3 PH) and SuHx PAH (Group 1 PAH) mice, and suppressed pyroptosis in pulmonary vascular cells. However, knockdown of DUSP4 counteracted the effects of PITX1 overexpression. Similar results were obtained in cultured PASMCs. In addition, treatment with the SE inhibitors JQ1 and iBET decreased the transcription of DUSP4 and increased the expression of hypoxia-induced pyroptosis proteins in PASMCs.

CONCLUSION

We confirmed that PITX1 can promote DUSP4 expression by binding to the DUSP4 promoter and SE to reduce pyroptosis in hypoxic PASMCs, providing new insights into the role of SEs and pyroptosis in pulmonary vascular remodeling and a theoretical basis for the treatment of PAH and related diseases.

Echinococcus granulosus sensu lato promotes osteoclast differentiation through DUSP4-MAPK signaling in osseous echinococcosis

Introduction

Osseous echinococcosis, caused by Echinococcus granulosus infection, is characterized by progressive bone destruction driven by abnormal osteoclast activation. Dual-specificity phosphatase 4 (DUSP4), a key negative regulator of the MAPK pathway, inhibits osteoclast differentiation and bone resorption. This study aimed to elucidate the role of DUSP4 in E. granulosus-induced bone loss.

Methods

In vitro, a co-culture system of E. granulosus protoscoleces (PSCs) and bone marrow-derived macrophages (BMMs) was established. Osteoclast differentiation and bone resorption were assessed using TRAP staining and F-actin immunofluorescence. Transcriptome sequencing identified DUSP4 as a key regulator. DUSP4 overexpression was performed to evaluate its effects on osteoclast markers and MAPK signaling (ERK, JNK, p38). In vivo, a mouse model of osseous echinococcosis was developed, and DUSP4 overexpression was achieved via lentiviral transduction. Bone destruction was analyzed using X-ray, micro-CT, and histology.

Results

PSCs significantly enhanced osteoclast differentiation and bone resorption, upregulated osteoclast markers (CTSK, NFATc1), and activated MAPK signaling. DUSP4 overexpression reversed these effects, reducing osteoclast activity and MAPK phosphorylation. In vivo, PSC infection caused severe bone destruction, which was mitigated by DUSP4 overexpression.

Disscussion

This study reveals the molecular mechanism by which Echinococcus granulosus drives abnormal osteoclast activation through the DUSP4-MAPK signaling axis. Parasitic infection suppresses DUSP4 expression, relieving its negative regulation of the MAPK pathway and leading to excessive osteoclast differentiation. Restoring DUSP4 expression effectively reverses abnormal MAPK pathway activation, reducing osteoclast bone resorption activity to physiological levels. These findings not only provide new insights into the pathological mechanisms of bone destruction in osseous echinococcosis but also establish DUSP4 as a critical therapeutic target for pathological bone resorption, laying the groundwork for host-directed treatment strategies for parasitic bone diseases.

DUSP4 inhibited tumor cell proliferation by downregulating glycolysis via p-ERK/p-PGK1 signaling in ovarian cancer

Ovarian cancer (OC) remains a leading cause of gynecological cancer-related mortality, with poor prognosis and limited therapeutic options, underscoring the urgent need for a deeper understanding of OC biology. In this study, we identified a marked reduction in dual-specificity phosphatase 4 (DUSP4) expression in OC tissues compared to benign ovarian masses, with even further decreases observed in metastatic lesions. Moreover, DUSP4 expression varied among OC subtypes, with the lowest levels observed in serous ovarian cancer, and was associated with P53 and KI67 protein levels, altered TP53 mutation rates, advanced tumor stages, and poorer prognosis. Functional experiments demonstrated that DUSP4 overexpression suppressed OC cell proliferation, migration, and invasion in vitro. Phosphoproteomic profiling via LC-MS/MS analysis identified the MAPK pathway and cellular metabolism as key downstream targets of DUSP4. Notably, DUSP4 overexpression reduced phosphorylation of PGK1 at Ser203, a critical regulator of anaerobic glycolysis, and decreased its mitochondrial localization, leading to reduced lactate production and increased ROS levels. Mechanistically, DUSP4 dephosphorylated p-ERK, disrupting its interaction with PGK1 and subsequently reducing PGK1 S203 phosphorylation. In vivo, DUSP4 overexpression significantly inhibited tumor growth in mouse models, accompanied by decreased p-ERK and PGK1 S203 levels. These findings highlight a regulatory axis involving DUSP4, p-ERK, and PGK1, through which DUSP4 modulates glycolysis and tumor progression. This study establishes DUSP4 as a prognostic biomarker and a potential therapeutic target for OC, offering new insights into its role in tumor metabolism and growth.

Chronic stress-induced cholesterol metabolism abnormalities promote ESCC tumorigenesis and predict neoadjuvant therapy response

Recent studies have demonstrated that chronic stress can enhance the development of multiple human diseases, including cancer. However, the role of chronic stress in esophageal carcinogenesis and its underlying molecular mechanisms remain unclear. This study uncovered that dysregulated cholesterol metabolism significantly promotes esophageal carcinogenesis under chronic stress conditions. Our findings indicate that the persistent elevation of glucocorticoids induced by chronic stress stimulates cholesterol uptake, contributing to esophageal carcinogenesis. The activated glucocorticoid receptor (GCR) enrichment at the promoter region of High Mobility Group Box 2 (HMGB2) facilitates its transcription. As a transcription coactivator, HMGB2 enhances Sterol Regulatory Element Binding Transcription Factor 1 (SREBF1) transcription and regulates cholesterol metabolism through LDL particle uptake into cells via Low Density Lipoprotein Receptor (LDLR). These results emphasize the significant impact of chronic stress on esophageal carcinogenesis and establish cholesterol metabolism disorder as a crucial link between chronic stress and the development of ESCC. The implications suggest that effectively managing chronic stress may serve as a viable strategy for preventing and treating ESCC.

LncRNA HAR1A inhibits non-small cell lung cancer growth by downregulating c-MYC transcripts and facilitating its proteasomal degradation

Non-small cell lung cancer (NSCLC) is a primary cause of cancer-related mortality on a global scale. Research increasingly shows that long non-coding RNAs (lncRNAs) play crucial regulatory roles and serve as biomarkers for diagnosis, prognosis, therapy monitoring, and druggable targets in NSCLC. We previously identified HAR1A as a tumor-suppressing lncRNA in NSCLC, with its loss also observed in oral and hepatocellular carcinoma. This study aimed to expand the understanding of the functional role of HAR1A in NSCLC and uncover its underlying mechanisms. Our results demonstrated that elevating HAR1A levels impeded NSCLC cell proliferation and migration but promoted apoptosis, thereby boosting their susceptibility to cisplatin. Subsequently, we discovered that HAR1A enhanced cisplatin's cytotoxicity in NSCLC cells by curbing adaptive autophagy through the downregulation of MYC. Further analysis revealed that HAR1A suppresses MYC by both lowering its transcript levels and promoting protein ubiquitination and degradation, thereby restricting tumor cell proliferation, migration, and adaptive autophagy. In exploring MYC's targets, we observed that MYC upregulated the transcription of heat shock protein 90 alpha family class B member 1 (HSP90AB1/HSP90β) gene. Rescue experiments verified that HAR1A mitigated NSCLC cell proliferation and migration and induced apoptosis through the MYC/HSP90β axis. Finally, we confirmed that HAR1A overexpression increased cisplatin efficacy in nude mouse NSCLC xenograft models.In conclusion, the findings suggest that HAR1A could be a promising therapeutic target in treating NSCLC and biomarkers for predicting chemotherapy outcomes. This study provides new insights into the molecular mechanisms of chemoresistance in NSCLC and underscores the potential of lncRNA-based strategies in cancer therapy.

Targeting Galectin-1 Overcomes Paclitaxel Resistance in Esophageal Squamous Cell Carcinoma

Resistance to paclitaxel poses a major obstacle in esophageal squamous cell carcinoma (ESCC) treatment. A better understanding of the mechanisms underlying paclitaxel resistance could help identify prognostic biomarkers and improved therapeutic strategies. In this study, we established a patient-derived xenograft model of acquired paclitaxel resistance and used RNA sequencing to identify galectin-1, encoded by LGALS1, as a key mediator of resistance. Integrative analysis of clinical data and physiological studies indicated that serum galectin-1 levels were elevated in resistant patients and correlated with treatment outcomes before and during taxane therapy. Importantly, exposing cells to serum from resistant patients resulted in increased paclitaxel resistance compared to serum from sensitive patients, which was closely associated with galectin-1 concentrations in the serum. The specific clearance of galectin-1 from resistant patient serum significantly restored paclitaxel sensitivity, and inhibiting galectin-1, through knockdown or the pharmacologic inhibitor OTX008, increased sensitivity to paclitaxel. Galectin-1 inhibition reduced the activity of β-catenin, thereby inhibiting stem cell properties induced by the Wnt/β-catenin pathway. Furthermore, galectin-1 regulated MDR1 transcription through increased nuclear accumulation of β-catenin, thus increasing resistance to paclitaxel. Combining OTX008 with clinical taxane formulations effectively reversed paclitaxel resistance in vitro and in vivo. Elevated galectin-1 levels thus serve as an indicator of response to paclitaxel therapy in ESCC, offering a therapeutic intervention strategy to overcome drug resistance. Significance: Galectin-1 is a key mediator of paclitaxel resistance in esophageal squamous cell carcinoma that can be targeted to improve taxane efficacy, suggesting broad therapeutic potential for treating various cancer types.

siRNA-based strategies to combat drug resistance in gastric cancer

Chemotherapy is a key treatment option for gastric cancer, but over 50% of patients develop either inherent or acquired resistance to these drugs, resulting in a 5-year survival rate of only about 20%. The primary treatment for advanced gastric cancer typically involves chemotherapy based on platinum or fluorouracil. Several factors can contribute to platinum resistance, including decreased drug uptake, increased drug efflux or metabolism, enhanced DNA repair, activation of pro-survival pathways, and inhibition of pro-apoptotic pathways. In recent years, there has been significant progress in biology aimed at finding innovative and more effective methods to overcome chemotherapy resistance. Small interfering RNAs (siRNAs) have emerged as a significant advancement in gene expression regulation, showing promise in enhancing the sensitivity of gastric cancer cells to chemotherapy drugs. However, siRNA therapies still face major challenges, particularly in terms of stability and efficient delivery in vivo. This article discusses the advances in siRNA therapy and its potential role in overcoming resistance to chemotherapeutic drugs such as cisplatin, 5-FU, doxorubicin, and paclitaxel in the treatment of gastric cancer.

DUSP4 enhances therapeutic sensitivity in HER2-positive breast cancer by inhibiting the G6PD pathway and ROS metabolism by interacting with ALDOB

BACKGROUND

Breast cancer (BC) poses a global threat, with HER2-positive BC being a particularly hazardous subtype. Despite the promise shown by neoadjuvant therapy (NAT) in improving prognosis, resistance in HER2-positive BC persists despite emerging targeted therapies. The objective of this study is to identify markers that promote therapeutic sensitivity and unravel the underlying mechanisms.

METHODS

We conducted an analysis of 86 HER2-positive BC biopsy samples pre-NAT using RNA-seq. Validation was carried out using TCGA, Kaplan‒Meier Plotter, and Oncomine databases. Phenotype verification utilized IC50 assays, and prognostic validation involved IHC on tissue microarrays. RNA-seq was performed on wild-type/DUSP4-KO cells, while RT‒qPCR assessed ROS pathway regulation. Mechanistic insights were obtained through IP and MS assays.

RESULTS

Our findings reveal that DUSP4 enhances therapeutic efficacy in HER2-positive BC by inhibiting the ROS pathway. Elevated DUSP4 levels correlate with increased sensitivity to HER2-targeted therapies and improved clinical outcomes. DUSP4 independently predicts disease-free survival (DFS) and overall survival (OS) in HER2-positive BC. Moreover, DUSP4 hinders G6PD activity via ALDOB dephosphorylation, with a noteworthy association with heightened ROS levels.

CONCLUSIONS

In summary, our study unveils a metabolic reprogramming paradigm in BC, highlighting DUSP4's role in enhancing therapeutic sensitivity in HER2-positive BC cells. DUSP4 interacts with ALDOB, inhibiting G6PD activity and the ROS pathway, establishing it as an independent prognostic predictor for HER2-positive BC patients.

Directly selecting cell-type marker genes for single-cell clustering analyses

In single-cell RNA sequencing (scRNA-seq) studies, cell types and their marker genes are often identified by clustering and differentially expressed gene (DEG) analysis. A common practice is to select genes using surrogate criteria such as variance and deviance, then cluster them using selected genes and detect markers by DEG analysis assuming known cell types. The surrogate criteria can miss important genes or select unimportant genes, while DEG analysis has the selection-bias problem. We present Festem, a statistical method for the direct selection of cell-type markers for downstream clustering. Festem distinguishes marker genes with heterogeneous distribution across cells that are cluster informative. Simulation and scRNA-seq applications demonstrate that Festem can sensitively select markers with high precision and enables the identification of cell types often missed by other methods. In a large intrahepatic cholangiocarcinoma dataset, we identify diverse CD8+ T cell types and potential prognostic marker genes.

Design, Synthesis, and Biological Evaluation of Potent and Selective PROTAC Degraders of Oncogenic KRASG12D

KRASG12D, the most frequent KRAS oncogenic mutation, is a promising target for cancer therapy. Herein, we report the design, synthesis, and biological evaluation of a series of KRASG12D PROTACs by connecting the analogues of MRTX1133 and the VHL ligand. Structural modifications of the linker moiety and KRAS inhibitor part suggested a critical role of membrane permeability in the degradation activity of the KRASG12D PROTACs. Mechanism studies with the representative compound 8o demonstrated that the potent, rapid, and selective degradation of KRASG12D induced by 8o was via a VHL- and proteasome-dependent manner. This compound selectively and potently suppressed the growth of multiple KRASG12D mutant cancer cells, displayed favorable pharmacokinetic and pharmacodynamic properties in mice, and showed significant antitumor efficacy in the AsPC-1 xenograft mouse model. Further optimization of 8o appears to be promising for the development of a new chemotherapy for KRASG12D-driven cancers as the complementary therapeutic strategy to KRAS inhibition.