Domperidone inhibits cell proliferation via targeting MEK and CDK4 in esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the leading causes of digestive system tumor related death in the world. Unfortunately, effective chemopreventive agent is lack for patients with ESCC in clinical practice, which leads to the extremely high mortality rate. METHODS: A library of prescribed drugs was screened for finding critical anti-tumor properties in ESCC cells. The phosphoproteomics, kinase array, pulldown assay and drug affinity responsive target stabilization assay (DARTS) were applied to explore mechanisms and searched for synergistic targets. Established models of PDX in mice were used to determine the therapeutic effect of domperidone. RESULTS: After screening a library of prescribed drugs, we discovered that domperidone has anti-tumor properties. Domperidone, acting as a gastroprokinetic agent, has been widely used in clinic for gastrointestinal motility disorders. Despite limited research, there are indications that domperidone may have anti-tumor properties. In this study, we determined that domperidone significantly inhibited ESCC proliferation in vitro and in vivo. We employed phosphoproteomics to reveal p-ERK, and p-SMAD3 down-regulation upon domperidone treatment. Then, the results of kinase assay and pulldown assay further validated that domperidone directly combined with MEK1/2 and CDK4, leading to the inhibition of their kinase activity. Furthermore, our results revealed that MEK/ERK and CDK4/SMAD3 signal pathway were major pathways in domperidone against ESCC. CONCLUSION: Collectively, these findings suggest that domperidone serves as an effective "multi-target" inhibitor of MEK1/2 and CDK4, offering potential benefits for the chemoprevention of ESCC.

Dihydroartemisinin inhibits the development of colorectal cancer by GSK-3ß/TCF7/MMP9 pathway and synergies with capecitabine.

Patients with colorectal cancer (CRC) suffer from poor prognosis and lack effective drugs. Dihydroartemisinin (DHA) has anti-cancer potential but the mechanism remains unclear. We elucidated the effects and mechanism of DHA on CRC development with the aim of providing an effective, low-toxicity drug and a novel strategy for CRC. Herein, proliferation assay, transwell assay, tube formation assay, metastasis models, PDX model and AOM/DSS model were used to reveal the effects of DHA on CRC. The key pathway and target were identified by RNA-seq, ChIP, molecular docking, pull down and dual-luciferase reporter assays. As a result, DHA showed a strong inhibitory effect on the growth, metastasis and angiogenesis of CRC with no obvious toxicity, and the inhibitory effect was similar to that of the clinical drug Capecitabine (Cap). Indeed, DHA directly targeted GSK-3ß to inhibit CRC development through the GSK-3ß/TCF7/MMP9 pathway. Meaningfully, DHA in combination with Cap enhanced the anti-cancer effect, and alleviated Cap-induced diarrhoea, immunosuppression and inflammation. In conclusion, DHA has the potential to be an effective and low-toxicity drug for the treatment of CRC. Furthermore, DHA in combination with Cap could be a novel therapeutic strategy for CRC with improved efficacy and reduced side effects.

A novel Fc-enhanced humanized monoclonal antibody targeting B7-H3 suppresses the growth of ESCC.

Esophageal squamous cell carcinoma (ESCC) is a prevalent malignant tumor of the digestive tract with a low 5-year survival rate due to the lack of effective treatment methods. Although therapeutic monoclonal antibodies (mAbs) now play an important role in cancer therapy, effective targeted mAbs are still lacking for ESCC. B7-H3 is highly expressed in a variety of tumors and has emerged as a promising therapeutic target. Several mAbs against B7-H3 have advanced to clinical trials, but their development has not yet been pursued for ESCC. Here, we developed a humanized and Fc-engineered anti-B7H3 mAb 24F-Hu-mut2 and systematically evaluated its anti-tumor activity in vitro and in vivo. The 24F-Hu-mut2 was humanized and modified in Fc fragment to obtain stronger antibody-dependent cell-mediated cytotoxicity(ADCC) activity and nanomolar affinity. Furthermore, both of ESCC cell-derived xenograft (CDX) and patient-derived xenograft (PDX) mice models indicated that 24F-Hu-mut2 displayed potent in vivo anti-tumor activity. In addition, a computational docking model showed that the mAb bound to IgC1 and IgC2 domain of B7-H3, which is closer to the cell membrane. Consistently, our ELISA results verified the binding of 24F-Hu-WT and IgC1 and IgC2. Our results indicate that 24F-Hu-mut2 has significant anti-ESCC activity both in vitro and in vivo, and this monoclonal antibody may be a promising antibody against ESCC and other B7-H3 overexpressing tumors.

Structural stability design of an optical mirror mount adjustment mechanism.

The stability of beam pointing in a laser system depends on the consistency of the optical mirror mount. Typically, a locking mechanism is used to secure the adjustment mechanism after beam alignment, ensuring the mount's stability. However, this process can introduce errors, causing a drift in the optical path. To mitigate this issue, in this study, an interference fit adjustment screw was designed. This development enables the mechanism to self-lock after beam alignment, thereby preventing optical path drift and enhancing overall stability. Specifically, 14 long-term thermal shock stability tests, each lasting 2500 min, were conducted to validate the proposed design. The experimental results showed that the thermal drift of the interference fit adjustment screw was reduced by 47.16%, thermal shift was reduced by 79.59%, and the long-term stability improved by at least 48.67%.

Gain optimization of an erbium-ytterbium co-doped amplifier via a Si3N4 photonic platform.

Erbium-doped waveguide amplifiers enable the integration of various active functions on a silicon platform. Er3+ can provide the basis for efficient optical amplification of photonic integrated circuits, but the gain is limited by cooperative upconversion leading to doping concentration limitations and insufficient optimization of the waveguide structure. In this paper, an erbium-ytterbium co-doped Al2O3 amplifier has been innovatively implemented on a low loss Si3N4 waveguide by careful design and optimization with the finite difference method. A more accurate and comprehensive theoretical model of erbium-ytterbium co-doping is established, with consideration of upconversions, energy transfer, amplified spontaneous radiation and propagation loss to perform optimization of the high-gain erbium-ytterbium co-doped waveguide amplifier. The optimized waveguide amplifier achieves a small-signal gain of more than 36 dB at 1550 nm under Er3+ concentration of 3 × 1020 cm-3 and Yb3+ concentration of 3 × 1021 cm-3. Endowing Si3N4 photonic integrated circuits with gain can enable the miniaturization of various on-chip based active devices.

PGC-1α promotes colorectal carcinoma metastasis through regulating ABCA1 transcription.

Colorectal cancer (CRC) is a highly aggressive cancer in which metastasis plays a key role. However, the mechanisms underlying metastasis have not been fully elucidated. Peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), a regulator of mitochondrial function, has been reported as a complicated factor in cancer. In this study, we found that PGC-1α was highly expressed in CRC tissues and was positively correlated with lymph node and liver metastasis. Subsequently, PGC-1α knockdown was shown to inhibit CRC growth and metastasis in both in vitro and in vivo studies. Transcriptomic analysis revealed that PGC-1α regulated ATP-binding cassette transporter 1 (ABCA1) mediated cholesterol efflux. Mechanistically, PGC-1α interacted with YY1 to promote ABCA1 transcription, resulting in cholesterol efflux, which subsequently promoted CRC metastasis through epithelial-to-mesenchymal transition (EMT). In addition, the study identified the natural compound isoliquiritigenin (ISL) as an inhibitor that targeted ABCA1 and significantly reduced CRC metastasis induced by PGC-1α. Overall, this study sheds light on how PGC-1α promotes CRC metastasis by regulating ABCA1-mediated cholesterol efflux, providing a basis for further research to inhibit CRC metastasis.

PHGDH promotes esophageal squamous cell carcinoma progression via Wnt/ß-catenin pathway.

PURPOSE: Esophageal squamous carcinoma (ESCC) with a high incidence in China, lacks effective therapeutic targets. Phosphoglycerate dehydrogenase (PHGDH) is a key enzyme in serine biosynthesis. However, the biological role of PHGDH in ESCC has not been revealed. METHODS: The expression of PHGDH in ESCC was investigated by UALCAN. The relationship between PHGDH expression and its prognostic value was analyzed by Kaplan-Meier and univariate Cox regression. Further, the potential functions of PHGDH involved in ESCC were explored through DAVID database and GSEA software. In addition, the expression of PHGDH was verified in ESCC. Then, the effects of PHGDH knockdown on ESCC were evaluated in vitro and in vivo by cell proliferation, clone formation, cell cycle, apoptosis, tube formation assays and ESCC cells derived xenograft model. In addition, western blotting and immunohistochemistry were used to detect the expression of Wnt/ß-catenin pathway which was associated with PHGDH. RESULTS: Bioinformatics analysis found that PHGDH was highly expressed in ESCC, and meaningfully, patients with high PHGDH expression had a poor prognosis. Moreover, the overexpression of PHGDH was verified in ESCC. Afterwards, PHGDH knockdown inhibited the cell proliferation, induced cell cycle arrest and apoptosis in ESCC cells, and inhibited the angiogenesis of HUVECs induced by ESCC conditioned medium, as well as inhibited the growth of xenograft tumor. Mechanistically, PHGDH knockdown inhibited Wnt/ß-catenin signaling pathway in ESCC. CONCLUSION: High expression of PHGDH predicts a poor prognosis for ESCC. PHGDH knockdown inhibits ESCC progression by suppressing Wnt/ß-catenin signaling pathway, indicating that PHGDH might be a potential target for ESCC therapy.

TOPK promotes the growth of esophageal cancer in vitro and in vivo by enhancing YB1/eEF1A1 signal pathway.

T-LAK-originated protein kinase (TOPK), a dual specificity serine/threonine kinase, is up-regulated and related to poor prognosis in many types of cancers. Y-box binding protein 1 (YB1) is a DNA/RNA binding protein and serves important roles in multiple cellular processes. Here, we reported that TOPK and YB1 were both highly expressed in esophageal cancer (EC) and correlated with poor prognosis. TOPK knockout effectively suppressed EC cell proliferation and these effects were reversible by rescuing YB1 expression. Notably, TOPK phosphorylated YB1 at Thr 89 (T89) and Ser 209 (S209) amino acid residues, then the phosphorylated YB1 bound with the promoter of the eukaryotic translation elongation factor 1 alpha 1 (eEF1A1) to activate its transcription. Consequently, the AKT/mTOR signal pathway was activated by up-regulated eEF1A1 protein. Importantly, TOPK inhibitor HI-TOPK-032 suppressed the EC cell proliferation and tumor growth by TOPK/YB1/eEF1A1 signal pathway in vitro and in vivo. Taken together, our study reveals that TOPK and YB1 are essential for the growth of EC, and TOPK inhibitors may be applied to retard cell proliferation in EC. This study highlights the promising therapeutic potential of TOPK as a target for treatment of EC.

Diosmetin suppresses the progression of ESCC by CDK2/Rb/E2F2/RRM2 pathway and synergies with cisplatin.

Cisplatin (CDDP) is the first-line drug in the clinical treatment of esophageal squamous cell carcinoma (ESCC), which has severe nephrotoxicity. Diosmetin (DIOS) can protect kidney from oxidative damage, however, its function in ESCC is unknown. This study aims to explore the effect and mechanism of DIOS on ESCC and its combined effect with CDDP. Herein, we found that DIOS significantly inhibited the progression of ESCC in vitro and in vivo. Furthermore, the anti-tumor effect of DIOS was not statistically different from that of CDDP. Mechanically, transcriptomics revealed that DIOS inhibited the E2F2/RRM2 signaling pathway. The transcriptional regulation of RRM2 by E2F2 was verified by luciferase assay. Moreover, docking model, CETSA, pull-down assay and CDK2 inhibitor assay confirmed that DIOS directly targeted CDK2, leading to significant suppression of ESCC. Additionally, the patient-derived xenografts (PDX) model showed that the combination of DIOS and CDDP significantly inhibited the growth of ESCC. Importantly, the combined treatment with DIOS and CDDP significantly reduced the mRNA expression levels of kidney injury biomarkers KIM-1 and NGAL in renal tissue, as well as the levels of blood urea nitrogen, serum creatinine and blood uric acid compared to the single treatment with CDDP. In conclusion, DIOS could be an effective drug and a potential chemotherapeutic adjuvant for ESCC treatment. Furthermore, DIOS could reduce the nephrotoxicity of CDDP to some extent.

Design and optimization of GI-PCF supporting the orbital angular momentum modes based on negative curvature structure.

Based on the negative curvature structure, we design a graded-index photonic crystal fiber (GI-PCF) supporting the orbital angular momentum (OAM) mode transmission and discuss its optimization strategy. The core of the designed GI-PCF is sandwiched by three-layer inner air-hole arrays with gradually decreasing air-hole radii and a single outer air-hole array, where the inner side of the annular core forms a graded refractive index distribution. All these structures are clad with negative-curvature tubes. By optimizing characteristic structural parameters, including the air-filling fraction of the outer array, the air-hole radii of the inner arrays, and the thickness of the tubes, the GI-PCF can support 42 OAM modes and most of them have a purity greater than 85%. Compared with conventional structures, the present design of GI-PCF has better properties on an overall level, which can stably transmit multiple OAM modes with high mode purity. These results inject new interest in the flexible design of PCF and have potential applications in various fields, including but not limited to the mode division multiplexing system and terabit data transmission.

Tegaserod Maleate Suppresses the Growth of Gastric Cancer In Vivo and In Vitro by Targeting MEK1/2.

Gastric cancer (GC) ranks fifth in global incidence and fourth in mortality. The current treatments for GC include surgery, chemotherapy and radiotherapy. Although treatment strategies for GC have been improved over the last decade, the overall five-year survival rate remains less than 30%. Therefore, there is an urgent need to find novel therapeutic or preventive strategies to increase GC patient survival rates. In the current study, we found that tegaserod maleate, an FDA-approved drug, inhibited the proliferation of gastric cancer cells, bound to MEK1/2 and suppressed MEK1/2 kinase activity. Moreover, tegaserod maleate inhibited the progress of gastric cancer by depending on MEK1/2. Notably, we found that tegaserod maleate suppressed tumor growth in the patient-derived gastric xenograft (PDX) model. We further compared the effect between tegaserod maleate and trametinib, which is a clinical MEK1/2 inhibitor, and confirmed that tegaserod maleate has the same effect as trametinib in inhibiting the growth of GC. Our findings suggest that tegaserod maleate inhibited GC proliferation by targeting MEK1/2.

Preliminary study on the role and mechanism of KIRREL3 in the development of esophageal squamous cell carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor of the digestive tract, which is very harmful to human health. The JAK-STAT signaling pathway is a recognized carcinogenic pathway that plays a role in the proliferation, apoptosis, migration, and invasion of a variety of cancer cells. Some studies have shown that the activation status of STAT3 affects the expression of KIRREL3. However, the expression of KIRREL3 in ESCC and its relationship with KIRREL3 or the JAK-STAT signaling pathway is still unclear. METHODS: In this study, we used immunohistochemistry and western blotting to analyze the protein expression levels of KIRREL3 in tumor tissues and ESCC cell lines. We applied proliferation assays, plate clone formation assays, Transwell assays, flow cytometry analysis, and CDX animal models to examine the role of KIRREL3 in ESCC. RESULTS: The results indicate that KIRREL3 is highly expressed to varying degrees in ESCC tissues and cell lines. Knocking down KIRREL3 expression in ESCC cells could correspondingly inhibit cell proliferation, colony formation, invasion, and migration, and had some effects on cell cycle progression and apoptosis. In addition, overexpressing KIRREL3 in these cells had opposite effects. Tumor formation in nude mice experiments also confirmed that KIRREL3 is involved in the growth of ESCC cells in vivo. CONCLUSIONS: These data suggest that KIRREL3 plays a key role in the development of ESCC, and KIRREL3 is a potential new target for the early diagnosis and clinical treatment of this disease.

Immunogenomic Landscape Analysis of Prognostic Immune-Related Genes in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death. HBV infection is an important risk factor for the tumorigenesis of HCC, given that the inflammatory environment is closely related to morbidity and prognosis. Consequently, it is of urgent importance to explore the immunogenomic landscape to supplement the prognosis of HCC. The expression profiles of immune-related genes (IRGs) were integrated with 377 HCC patients to generate differentially expressed IRGs based on the Cancer Genome Atlas (TCGA) dataset. These IRGs were evaluated and assessed in terms of their diagnostic and prognostic values. A total of 32 differentially expressed immune-related genes resulted as significantly correlated with the overall survival of HCC patients. The Gene Ontology functional enrichment analysis revealed that these genes were actively involved in cytokine-cytokine receptor interaction. A prognostic signature based on IRGs (HSPA4, PSME3, PSMD14, FABP6, ISG20L2, TRAF3, NDRG1, NRAS, CSPG5, and IL17D) stratified patients into high-risk versus low-risk groups in terms of overall survival and remained as an independent prognostic factor in multivariate analyses after adjusting for clinical and pathologic factors. Several IRGs (HSPA4, PSME3, PSMD14, FABP6, ISG20L2, TRAF3, NDRG1, NRAS, CSPG5, and IL17D) of clinical significance were screened in the present study, revealing that the proposed clinical-immune signature is a promising risk score for predicting the prognosis of HCC.

AGT serves as a potential biomarker and drives tumor progression in colorectal carcinoma.

BACKGROUND: Colorectal carcinoma (CRC) is one of the most common aggressive tumors worldwide, and it is necessary to identify candidate biomarkers and therapeutic targets in CRC to improve patient outcomes. METHODS: The differentially expressed genes (DEGs) were obtained from CRC microarray. Functional enrichment was performed to explore the function of DEGs, and core genes were identified by Cytoscape. Then, the diagnosis and prognosis markers were identified by ROC curve and survival analyses. More importantly, a series of in vitro studies were conducted in CRC cells to explore the function of the selected biomarker. Further, the drug response was performed by Cancer Cell Line Encyclopedia (CCLE) and Cancer Therapy Response Portal (CTRP). In addition, the effect of drug on CRC cells was evaluated by functional experiments. RESULTS: The identified DEGs were mainly associated with the processes relating to tumorigenesis. 25 core genes were selected and angiotensinogen (AGT) was filtered out as a diagnosis and prognosis biomarker. Comprehensive in vitro experiments showed that AGT attributed to the proliferation, migration, and invasion of CRC cells, as well as angiogenesis of HUVECs induced by CRC conditional medium. Furthermore, drug response analysis implied that AGT expression was associated with isoliquiritigenins (ISL). Additionally, ISL could suppress the progression of CRC cells. CONCLUSIONS: AGT is identified as diagnosis and prognosis prediction of CRC. Moreover, AGT attributes to the progression of CRC. Additionally, AGT exhibits fine drug response to ISL, and ISL is also evaluated as potential therapy drug in CRC.

Cloperastine inhibits esophageal squamous cell carcinoma proliferation in vivo and in vitro by suppressing mitochondrial oxidative phosphorylation.

Esophageal squamous cell carcinoma (ESCC) is a major type of esophageal cancer. The prognosis of patients with ESCC remains poor because of the high morbidity and mortality of the disease. One strategy for drug discovery for ESCC treatment or prevention is screening FDA-approved drugs. In the present study, we found that the antitussive agent cloperastine can inhibit the proliferation of ESCC cells. However, the underlying mechanism was unclear. To determine the mechanism of this inhibitory effect, we performed proteomic analysis using KYSE150 cells treated with cloperastine and DMSO. The results identified several down-regulated signaling pathways included those of three key proteins (NADH dehydrogenase [ubiquinone] 1 alpha subcomplex 1, NADH ubiquinone oxidoreductase subunit S5, and cytochrome C oxidase subunit 6B1) involved in oxidative phosphorylation. Meanwhile, we observed that oxidative phosphorylation in mitochondria was inhibited by the drug. Importantly, cloperastine suppressed ESCC growth in a xenograft mouse model in vivo. Our findings revealed that cloperastine inhibits the proliferation of ESCC in vivo and in vitro by suppressing mitochondrial oxidative phosphorylation.

DNA polymerase ß deficiency promotes the occurrence of esophageal precancerous lesions in mice.

Esophageal mucosa undergoes mild, moderate, severe dysplasia, and other precancerous lesions and eventually develops into carcinoma in situ, and understanding the developmental progress of esophageal precancerous lesions is beneficial to prevent them from developing into cancer. DNA polymerase ß (Polß), a crucial enzyme of the base excision repair system, plays an important role in repairing damaged DNA and maintaining genomic stability. Abnormal expression or deletion mutation of Polß is related to the occurrence of esophageal cancer, but the role of Polß deficiency in the esophageal precancerous lesions is still unclear. Here, esophageal mucosa Polß-knockout mice were used to explore the relationship of Polß deficiency with esophageal precancerous lesions. First, we found the degree and number of esophageal precancerous lesions in Polß-KO mice were more serious than those in Polß-Loxp mice after N-nitrosomethylbenzylamine (NMBA) treatment. Whole exome sequencing revealed that deletion of Polß increased the frequency of gene mutations. Gene expression prolife analysis showed that the expression of proteins correlated to cell proliferation and the cell cycle was elevated in Polß-KO mice. We also found that deletion of Polß promoted the proliferation and clone formation as well as accelerated cell cycle progression of human immortalized esophageal epithelial cell line SHEE treated with NMBA. Our findings indicate that Polß knockout promotes the occurrence of esophageal precancerous lesions.

Bestatin Cream Impairs Solar Simulated Light‒Driven Skin Inflammation and Skin Carcinogenesis in Mice.

Leukotriene A4 hydrolase (LTA4H) is an enzyme that catalyzes the production of the inflammatory mediator leukotriene B4, which is involved in inflammatory responses mediated through the leukotriene B4/leukotriene B4 receptor type 1 (BLT1) signaling pathway. In this study, we investigated whether bestatin, an LTA4H inhibitor, could suppress skin acute inflammation and carcinogenesis. In the clinical sample, BLT1 was significantly induced in human skin tissues after acute solar simulated light (SSL) exposure. BLT1 and NF-κB p65 expressions were also increased in acute SSL‒induced mouse skin tissue. Furthermore, LTA4H and BLT1 were highly expressed in skin chronic inflammation and squamous cell carcinomas. More importantly, topical administration of bestatin cream dramatically inhibited BLT1 expression in acute SSL‒induced human skin tissues. BLT1 and NF-κB p65 expressions were also suppressed in acute SSL‒induced Lta4h-knockout and bestatin-treated mice skin tissues. Moreover, we conducted long-term prevention and therapeutic studies, which showed that bestatin significantly attenuated SSL-induced skin carcinogenesis. Mechanistic studies showed that bestatin inhibited skin carcinogenesis by suppressing cell proliferation and inducing cell apoptosis through LTA4H‒BLT1‒protein kinase B‒NF-κB p65 pathway. Overall, our results suggest that topical application of novel cream containing bestatin might open a helpful avenue for SSL-induced skin carcinogenesis.

Allogenic mouse cell vaccine inhibits lung cancer progression by inhibiting angiogenesis.

Aim: This research investigated the therapeutic effect of an allogeneic mouse brain microvascular endothelial cell vaccine on lung cancer and further elucidated its potential anti-angiogenic mechanism. Materials & methods: The immune effect of the allogeneic bEnd.3 vaccine and DC vaccine loaded with bEnd.3 antigen on the subcutaneous transplantation of Lewis lung cancer (LLC) was assessed by ELISA, the CCK test and the CTL killing test. The mechanism was preliminarily revealed by immunohistochemistry and immunoblot analysis. Results: This study revealed that tumor volume was decreased (p < .01) and the survival was prolonged significantly (p < .05) by the bEnd.3 vaccine in subcutaneous LLC transplantation in the vaccine prevention group. In contrast, both tumor volume in the serum therapeutic group and survival of bEnd.3 vaccine were not significantly different from those of the control group (p > .05). Importantly, tumor volume and survival of the T lymphocyte therapeutic group were decreased and prolonged (p < .05). In addition, both tumor volume and survival of DC vaccine loaded with bEnd.3 in the vaccine prevention group were decreased and prolonged significantly (p < .01). Furthermore, bEnd.3 vaccine and DC vaccine loaded with bEnd.3 both produced the activity of killing bEnd.3 target cells in vitro.The reason may induce the immune mice to produce anti-VEGFR-II, anti-endoglin and anti-integrin αν antibodies to have an anti-angiogenesis function. Conclusion: The allogeneic mouse bEnd.3 cell vaccine can block angiogenesis and prevent the development of lung cancer transplantation tumors.

p21-activated kinase 4 promotes the progression of esophageal squamous cell carcinoma by targeting LASP1.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors of the digestive tract in humans. Several studies have indicated that PAK4 is associated with the risk of ESCC and may be a potential druggable kinase for ESCC treatment. However, the underlying mechanism remains largely unknown. The aim of our study is to identify the functional role of PAK4 in ESCC. To determine the expression of PAK4 in ESCC, Western blot analysis and immunohistochemistry were performed, and the results showed that PAK4 is significantly upregulated in ESCC tissues and cell lines compared with normal controls and normal esophageal epithelial cell line. To further investigate the role of PAK4 in ESCC, cell viability assays, anchorage-independent cell growth assays, wound healing assays, cellular invasion assays, in vivo xenograft mouse models, and metastasis assays were conducted, and the results showed that PAK4 can significantly facilitate ESCC proliferation and metastasis in vitro and in vivo. To determine the potential target of PAK4 in ESCC progression, a pull-down assay was performed, and the results showed that LASP1 may be a potential target of PAK4. An immunoprecipitation assay and confocal microscopy analysis confirmed that PAK4 can bind to and colocalize with LASP1 in vitro and in cells. Notably, rescue experiments further illustrated the mechanistic network of PAK4/LASP1. Our research reveals the oncogenic roles of PAK4 in ESCC and preliminarily elucidates the mechanistic network of PAK4/LASP1 in ESCC.

Proteomics Reveal the Inhibitory Mechanism of Levodopa Against Esophageal Squamous Cell Carcinoma.

High recurrence rates and poor survival of patients with esophageal squamous cell carcinoma (ESCC) after treatment make ongoing research on chemoprevention drugs for ESCC particularly important. In this study, we screened a large number of FDA-approved drugs and found levodopa, a drug used to treat Parkinson's disease, had an inhibitory effect on the growth of ESCC cells. To elucidate the molecular mechanisms involved, we applied quantitative proteomics to investigate the anti-tumor activity of levodopa on ESCC. The results suggest that levodopa could down-regulate oxidative phosphorylation, non-alcoholic fatty liver disease, and Parkinson's disease pathways. Major mitochondrial respiratory compounds were involved in the pathways, including succinate dehydrogenase subunit D, NADH-ubiquinone oxidoreductase Fe-S protein 4, and mitochondrial cytochrome c oxidase subunit 3. Down-regulation of these proteins was associated with mitochondrial dysfunction. Western blotting and immunofluorescence results confirmed the proteomics findings. Cell viability assays indicated mitochondrial activity was suppressed after levodopa treatment. Reduced mitochondrial membrane potential was detected using JC-1 staining and TMRE assays. Transmission electron microscopy revealed changes in the morphology of mitochondria. Taken together, these results indicate that levodopa inhibited the growth of ESCC through restraining mitochondria function.