Novel ESCC-related gene ZNF750 as potential Prognostic biomarker and inhibits Epithelial-Mesenchymal Transition through directly depressing SNAI1 promoter in ESCC

Bmal1-Mediated Circadian MELK Expression Potentiates MELK Inhibitor Chronotherapy for Esophageal Cancer

Esophageal squamous cell carcinoma (ESCC) remains a global health challenge. Circadian clock and maternal embryonic leucine zipper kinase (MELK) play a key role in tumorigenesis. However, a link between circadian clock dysregulation and MELK function in the occurrence and development of ESCC remains elusive. Here, In the in vivo and in vitro systems, we found for the first time that MELK exhibits pronounced circadian rhythms expression in mice esophageal tissue, xenograft model, and human ESCC cells. The diurnal differences expression between peak (ZT0) and trough (ZT12) points in normal esophageal tissue is nearly 10-fold. Circadian expression of MELK in ESCC cells was regulated by Bmal1 through binding to the MELK promoter. Supporting this, the levels of MELK were increased significantly in patients with ESCC and were accompanied by altered expression of core clock genes, especially, since Bmal1 is prominently upregulated. Most importantly, Bmal1-deleted eliminated the rhythmic expression of MELK, whereas the knockdown of other core genes had no effect on MELK expression. Furthermore, in nude mice with transplanted tumors, the anticancer effect of OTS167 at ZT0 administration is twice that of ZT12. Implications: Our findings suggest that MELK represents a therapeutic target, and can as a regulator of circadian control ESCC growth, with these findings advance our understanding of the clinical potential of chronotherapy and the importance of time-based MELK inhibition in cancer treatment.

SND1-SMARCA5 interaction strengthened by PIM promotes the proliferation, metastasis, and chemoresistance of esophageal squamous cell carcinoma

Chromatin remodeling plays a pivotal role in the progression of esophageal squamous cell carcinoma (ESCC), but the precise mechanisms remain poorly understood. Here, we elucidated the critical function of staphylococcal nuclease and tudor domain-containing 1 (SND1) in modulating chromatin dynamics, thereby driving ESCC progression in both in vitro and in vivo models. Our data revealed that SND1 was markedly overexpressed in ESCC cell lines. Silencing SND1 disrupted histone modifications, attenuated RNA polymerase II activity, and precipitated increased chromosomal aberrations and DNA damage, particularly following camptothecin treatment. These molecular perturbations culminated in diminished cellular proliferation, metastasis, and chemoresistance. We further identified that the regulatory effects of SND1 on chromatin were mediated through its interaction with SMARCA5, a process potentiated by PIM1-catalyzed phosphorylation of SND1 at serine 426. This SND1-SMARCA5 interaction was essential for the transcriptional activation of CUX1, a key oncogene implicated in ESCC progression. Notably, disruption of SND1S426 phosphorylation impaired the SND1-SMARCA5 interaction, leading to significant inhibition of ESCC tumor growth and metastatic potential in vivo. Our findings unveil a novel mechanistic axis involving SND1 and SMARCA5 in chromatin remodeling and oncogenesis, offering promising therapeutic targets for ESCC intervention.

FBXW7 metabolic reprogramming inhibits the development of colon cancer by down-regulating the activity of arginine/mToR pathways

FBXW7 is a tumor suppressor gene that regulates metabolism and is associated with the onset and progression of colorectal cancer (CRC)), however, the precise mechanism whereby FBXW7 participates in the metabolic reprogramming of CRC remains unclear. Here, the research aims to reveal the association between the expression of FBXW7 and clinical variables and to investigate the molecular mechanism by which FBXW7 plays a critical role in the development of CRC. The clinical importance of FBXW7 in CRC was determined by immunohistochemistry. Non-targeted metabolomics was utilized to explore the role of FBXW7 in the metabolic regulation of CRC. Low expression of FBXW7 was associated with poor prognosis in individuals with CRC, both at the mRNA and protein levels. FBXW7 over-expression inhibited CRC cell growth, colony formation, migration, and invasion. Non-targeted metabolomics unveiled that FBXW7 over-expression directly caused the deprivation of arginine which led to downmodulation of mTOR signaling pathway; meanwhile, FBXW7-related metabolites were primarily concentrated in the mTOR signaling pathway. In summary, the research identified a novel mechanism of action of FBXW7 in CRC. The research findings provide a theoretical foundation for the prognostic prediction and therapeutic planning of CRC based on metabolic reprogramming.

GPR37-enhanced ubiquitination of ATP1A1 inhibits tumor progression and radiation resistance in esophageal squamous cell carcinoma

Radiotherapy resistance is one of the main reasons for the dismal clinical outcome of patients with esophageal squamous cell carcinoma (ESCC). Therefore, clarifying the targets and molecular mechanisms of radiotherapy resistance in ESCC is of great theoretical and clinical significance to enhance the efficacy of radiotherapy. In this study, GPR37 was identified as a key factor facilitating ESCC radiosensitization. We found that GPR37 is lowly expressed in ESCC, especially in radioresistant ESCC tumors. And its insufficiency is related to the malignant characteristics and unfavorable prognosis in ESCC. Further investigation revealed that GPR37 level is inversely regulated by promoter methylation but positively regulated by ZNF750. Functionally, GPR37 could not only overcome radioresistance of ESCC, but also inhibit proliferation, migration, and invasion. Mechanistically, GPR37 interacts with the ATP1A1 protein, effectively promoting its ubiquitination-induced degradation, thereby limiting the activation of the AKT/mTOR signaling pathway. Additionally, GPR37 can be transported to recipient cells via exosomes and inhibit the malignant behavior of recipient cells. Overall, these findings suggest that GPR37-ATP1A1 axis holds potential as a therapeutic target for the management of ESCC, especially for overcoming radiation resistance.

TRIM-endous functional network of tripartite motif 29 (TRIM29) in cancer progression and beyond

While most Tripartite motif (TRIM) family proteins are E3 ubiquitin ligases, some members have functions beyond the regulation of ubiquitination, impacting normal physiological processes and disease progression. TRIM29, an important member of the TRIM family, exerts a predominant influence on cancer growth, epithelial-to-mesenchymal transition, stemness and metastatic progression by directly potentiating multiple canonical oncogenic pathways. The cancer-promoting effect of TRIM29 is also evident in metabolic interventions and interference with the efficacy of cancer therapeutics. As expected for any key node in cancer, the expression of TRIM29 is tightly regulated by non-coding RNAs, epigenetic modulation, and post-translational regulation. A systematic discussion of how TRIM29 is regulated in cancer, its influences on cancer progression, and its impact on cancer therapeutics is presented in this review. We also explore the context-dependent alterations between TRIM29 function from oncogenic to tumor suppression. As TRIM29 is involved in multiple aspects of cancer progression, a better understanding of its biological impact in cancer may help improve prognosis and develop novel therapeutic combinations, leading to improved personalized cancer care.

Oxymatrine inhibits migration and invasion of esophageal squamous cell carcinoma cell lines via the MEK1/ERK/β-catenin pathway

Esophageal, cancer is a prevalent malignant tumour of the digestive system in China, and esophageal squamous cell carcinoma (ESCC) accounts for 90 % of all esophageal cancer cases. Currently, the primary treatment involves surgical resection combined with postoperative radiotherapy. In this study, we used two ESCC cell lines to determine whether oxymatrine (OMT) inhibits ESCC, whether the mechanism involves the MEK1/ERK/β-catenin pathway, and how OMT modulates this pathway to affect the development of ESCC. The effects of OMT treatment were monitored with Cell Counting Kit-8 (CCK-8) assays as well as with clony formation, migration and invasion, wound healing, Hoechst 33258, and Western blot analyses. The relationship between OMT and the target was also evaluated by molecular docking and cell stability experiments. These findings suggest that ESCC development and metastasis may be inhibited by OMT and that OMT targets MEK1 through the ERK/β-catenin/EMT pathway to suppress ESCC cell migration and invasion. In addition, in vivo studies confirmed that OMT can inhibit the growth of ESCC cell lines in NOG mice without causing damage to other organs. In conclusion, in vitro experiments, revealed that OMT prevents the migration and invasiveness of ESCC cells by inhibiting the ERK/β-catenin/EMT pathway and thus targeting MAP2K1 (MEK1) in ESCC.

ZNF652 exerts a tumor suppressor role in lung cancer by transcriptionally downregulating cyclin D3

Dysfunction of zinc finger protein 652 (ZNF652) is associated with various malignant tumors. However, the role of ZNF652 in lung cancer (LC) is poorly understood. Here, we identified that ZNF652 was downregulated in human LC tissues and cell lines. Low ZNF652 expression was associated with poor survival in LC patients. Overexpression of ZNF652 inhibited cell viability, proliferation, migration, and invasion of LC cells, whereas ZNF652 knockdown promoted these malignant phenotypes. Using RNA-seq analysis revealed that ZNF652 overexpression resulted in obvious alterations of various biological processes, especially cell cycle and cellular senescence. Subsequently, we confirmed that ZNF652 overexpression arrested the cell cycle at the G1 phase, increased ROS-mediated DNA damage, induced LC cell senescence, and enhanced cisplatin-induced apoptosis in LC cells. Mechanistically, ZNF652 directly bound to the promoter of cyclin D3 (CCND3), inhibited its transcription, thereby arresting the cell cycle at the G1 phase. Ectopic expression of cyclin D3 rescued the decreased cell viability and cell cycle arrest induced by ZNF652. In vivo studies further showed that ZNF652 overexpression suppressed the tumorigenic potential of LC. Collectively, our findings reveal that ZNF652 exerts a tumor suppressor role in lung cancer by inducing cell cycle arrest and cellular senescence via transcriptionally downregulating cyclin D3. Thus, ZNF652 may be a prognostic predictive factor for LC patients.

FUT6 Suppresses the Proliferation, Migration, Invasion, and Epithelial-Mesenchymal Transition of Esophageal Carcinoma Cells via the Epidermal Growth Factor Receptor/Extracellular Signal-Regulated Kinase Signaling Pathway

Esophageal cancer (ESCA) is a high-incidence disease worldwide, of which the 5-year survival rate remains dismal since the cellular basis of ESCA remains largely unclear. Herein, we attempted to examine the manifestation of fucosyltransferase-6 (FUT6) in ESCA and the associated mechanisms. The GSE161533 dataset was used to analyze a crucial gene in ESCA. The expression of FUT6 was investigated in normal esophageal epithelial cells and ESCA cell lines. Following FUT6 knockdown or overexpression, cell proliferation, migration, invasion, and levels of epithelial–mesenchymal transition (EMT)-related and epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinase (ERK) signaling pathway-related proteins were evaluated using CCK-8, Transwell, and Western blotting with antibodies against EGFR, p-EGFR, E-cadherin, Vimentin, N-cadherin, ERK1/2, and p-ERK1/2), respectively. EGF was administered to stimulate the EGFR/ERK signaling pathway, followed by the assessment of cellular activity. Database analysis revealed that FUT6 was downregulated in the ESCA cells. Our study indicated that FUT6 is suppressed in various ESCA cell lines. Moreover, cell proliferation, invasion, migration, and EMT-related protein levels were conspicuously enhanced or restrained by FUT6 disruption or overexpression. FUT6 overexpression suppressed the malignant activities of the cells when stimulated by EGF, including inhibition of cell growth, movement, invasion, and EMT advancement, as well the reduction the levels of EGFR/ERK pathway proteins. In conclusion, FUT6 can suppress the EGFR/ERK signaling pathway activated by EGF, leading to the potential attenuation of ESCA cell proliferation, invasion, migration, and EMT.

Screening and verification of hub genes in esophageal squamous cell carcinoma by integrated analysis

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors. However, the mechanisms underlying ESCC tumorigenesis have not been fully elucidated. Thus, we aimed to determine the key genes involved in ESCC tumorigenesis. The following bioinformatics analyses were performed: identification of differentially expressed genes (DEGs); gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis; integrated analysis of the protein-protein interaction network and Gene Expression Profiling Interactive Analysis database for validation of hub genes. Finally, western blotting and qPCR were used to explore the expression of cell division cycle 6 (CDC6) in ESCC cell lines. Immunohistochemistry analysis of ESCC samples from patients and matched clinical characteristics was used to determine the effects of CDC6. A total of 494 DEGs were identified, and functional enrichment was mainly focused on cell cycle and DNA replication. Biological pathway analysis of the hub genes was closely related to the cell cycle. We found that CDC6 was upregulated in ESCC cell lines and patient tissues and was related to the clinicopathological characteristics of ESCC. In conclusion, this study identified hub genes and crucial biological pathways related to ESCC tumorigenesis and integrated analyses indicated that CDC6 may be a novel diagnostic and therapeutic target for ESCC.

Genetic and molecular characterization of metabolic pathway-based clusters in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive types of squamous cell carcinoma and represents a significant proportion of esophageal cancer. Metabolic reprogramming plays a key role in the occurrence and development of ESCC. Unsupervised clustering analysis was employed to stratify ESCC samples into three clusters: MPC1-lipid type, MPC2-amino acid type, and MPC3-energy type, based on the enrichment scores of metabolic pathways extracted from the Reactome database. The MPC3 cluster exhibited characteristics of energy metabolism, with heightened glycolysis, cofactors, and nucleotide metabolism, showing a trend toward increased aggressiveness and poorer survival rates. On the other hand, MPC1 and MPC2 primarily involved lipid and amino acid metabolism, respectively. In addition, liquid chromatography‒mass spectrometry-based metabolite profiles and potential therapeutic agents were explored and compared among ESCC cell lines with different MPCs. MPC3 amplified energy metabolism markers, especially carnitines. In contrast, MPC1 and MPC2 predominantly had elevated levels of lipids (primarily triacylglycerol) and amino acids, respectively. Furthermore, MPC3 demonstrated a suboptimal clinical response to PD-L1 immunotherapy but showed increased sensitivity to the doramapimod chemotherapy regimen, as evident from drug sensitivity evaluations. These insights pave the way for a more personalized therapeutic approach, potentially enhancing treatment precision for ESCC patients.

The role of zinc finger proteins in malignant tumors

Zinc finger proteins (ZNFs) are the largest family of transcriptional factors in mammalian cells. Recently, their role in the development, progression, and metastasis of malignant tumors via regulating gene transcription and translation processes has become evident. Besides, their possible involvement in drug resistance has also been found, indicating that ZNFs have the potential to become new biological markers and therapeutic targets. In this review, we summarize the oncogenic and suppressive roles of various ZNFs in malignant tumors, including lung, breast, liver, gastric, colorectal, pancreatic, and other cancers, highlighting their role as prognostic markers, and hopefully provide new ideas for the treatment of malignant tumors in the future.

TRIM29 hypermethylation drives esophageal cancer progression via suppression of ZNF750

Esophageal cancer (ESCA) is the seventh most frequent and deadly neoplasm. Due to the lack of early diagnosis and high invasion/metastasis, the prognosis of ESCA remains very poor. Herein, we identify skin-related signatures as the most deficient signatures in invasive ESCA, which are regulated by the transcription factor ZNF750. Of note, we find that TRIM29 level strongly correlated with the expression of many genes in the skin-related signatures, including ZNF750. TRIM29 is significantly down-regulated due to hypermethylation of its promoter in both ESCA and precancerous lesions compared to normal tissues. Low TRIM29 expression and high methylation levels of its promoter are associated with malignant progression and poor clinical outcomes in ESCA patients. Functionally, TRIM29 overexpression markedly hinders proliferation, migration, invasion, and epithelial-mesenchymal transition of esophageal cancer cells, whereas opposing results are observed when TRIM29 is silenced in vitro. In addition, TRIM29 inhibits metastasis in vivo. Mechanistically, TRIM29 downregulation suppresses the expression of the tumor suppressor ZNF750 by activating the STAT3 signaling pathway. Overall, our study demonstrates that TRIM29 expression and its promoter methylation status could be potential early diagnostic and prognostic markers. It highlights the role of the TRIM29-ZNF750 signaling axis in modulating tumorigenesis and metastasis of esophageal cancer.

Role of E2F transcription factor in Oral cancer: Recent Insight and Advancements

The family of mammalian E2F transcription factors (E2Fs) comprise of 8 members (E2F1-E2F8) classified as activators (E2F1-E2F3) and repressors (E2F4-E2F8) primarily regulating the expression of several genes related to cell proliferation, apoptosis and differentiation, mainly in a cell cycle-dependent manner. E2F activity is frequently controlled via the retinoblastoma protein (pRb), cyclins, p53 and the ubiquitin-proteasome pathway. Additionally, genetic or epigenetic changes result in the deregulation of E2F family genes expression altering S phase entry and apoptosis, an important hallmark for the onset and development of cancer. Although studies reveal E2Fs to be involved in several human malignancies, the mechanisms underlying the role of E2Fs in oral cancer lies nascent and needs further investigations. This review focuses on the role of E2Fs in oral cancer and the etiological factors regulating E2Fs activity, which in turn transcriptionally control the expression of their target genes, thus contributing to cell proliferation, metastasis, and drug/therapy resistance. Further, we will discuss therapeutic strategies for E2Fs, which may prevent oral tumor growth, metastasis, and drug resistance.

Identification of Tumor Suppressor Gene LHPP-Based 5-microRNA Signature That Predicts the Early- and Midstage Esophageal Squamous Cell Carcinoma: A Two-Stage Case-Control Study in the Chinese Han Population

Objective

To establish a novel approach for diagnosing early- and midstage esophageal squamous cell carcinoma (ESCC).

Methods

The tumor suppressor gene phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP)–based miRNA signature was identified using next-generation sequencing and 3 biological online prediction systems. This retrospective study established and validated an ESCC prediction model using a test cohort and a validation cohort.

Results

Immunohistochemical staining and real-time quantitative polymerase chain reaction (RT-qPCR) results showed that LHPP protein levels were significantly lower in tissues with early- and midstage ESCC than in adjacent tissues (P < .01). Further, we confirmed that miR-15b-5p, miR-424-5p, miR-497-5p, miR-363-5p, and miR-195-5p inhibited LHPP. These 5 miRNAs were significantly elevated in the plasma of early- and midstage ESCC (P < .05). An ESCC prediction model combining these 5 miRNAs was established. Finally, in the external validation cohort, the model exhibited high discriminative value (sensitivity/specificity: 84.4%/93.3%).

Conclusions

The prediction model has potential implications for diagnosis of early- and midstage ESCC.

Whole-genome sequencing of extrachromosomal circular DNA of cerebrospinal fluid of medulloblastoma

BACKGROUND

Medulloblastoma (MB) is a malignant tumor associated with a poor prognosis in part due to a lack of effective detection methods. Extrachromosomal circular DNA (eccDNA) has been associated with multiple tumors. Nonetheless, little is currently known on eccDNA in MB.

METHODS

Genomic features of eccDNAs were identified in MB tissues and matched cerebrospinal fluid (CSF) and compared with corresponding normal samples using Circle map. The nucleotides on both sides of the eccDNAs' breakpoint were analyzed to understand the mechanisms of eccDNA formation. Bioinformatics analysis combined with the Gene Expression Omnibus (GEO) database identified features of eccDNA-related genes in MB. Lasso Cox regression model, univariate and multivariate Cox regression analysis, time-dependent ROC, and Kaplan-Meier curve were used to assess the potential diagnostic and prognostic value of the hub genes.

RESULTS

EccDNA was profiled in matched tumor and CSF samples from MB patients, and control, eccDNA-related genes enriched in MB were identified. The distribution of eccDNAs in the genome was closely related to gene density and the mechanism of eccDNA formation was evaluated. EccDNAs in CSF exhibited similar distribution with matched MB tissues but were differentially expressed between tumor and normal. Ten hub genes prominent in both the eccDNA dataset and the GEO database were selected to classify MB patients to either high- or low-risk groups, and a prognostic nomogram was thus established.

CONCLUSIONS

This study provides preliminary evidence of the characteristics and formation mechanism of eccDNAs in MB and CSF. Importantly, eccDNA-associated hub genes in CSF could be used as diagnostic and prognostic biomarkers for MB.

Palbociclib Enhances Migration and Invasion of Cancer Cells via Senescence-Associated Secretory Phenotype-Related CCL5 in Non-Small-Cell Lung Cancer

Palbociclib is the first CDK4/6 inhibitor approved by FDA and has been studied in many types of cancer. However, some studies showed that it could induce epithelial-mesenchymal transition (EMT) of cancer cells. To test the effect of palbociclib on non-small-cell lung cancer (NSCLC) cells, we treated NSCLC cells with different concentrations of palbociclib and detected its effects via MTT, migration and invasion assays, and apoptosis test. Further RNA sequencing was performed in the cells treated with 2 μM palbociclib or control. And Gene Ontology, Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Set Enrichment Analysis (GSEA), and protein-protein interaction network (PPI) were analyzed to explore the mechanism of palbociclib. The results showed that palbociclib significantly inhibited the growth of NSCLC cells and promoted apoptosis of cells, however, enhanced the migration and invasion abilities of cancer cells. RNA sequencing showed that cell cycle, inflammation-/immunity-related signaling, cytokine-cytokine receptor interaction, and cell senescence pathways were involved in the process, and CCL5 was one of the significantly differential genes affected by palbociclib. Further experiments showed that blocking CCL5-related pathways could reverse the malignant phenotype induced by palbociclib. Our results revealed that palbociclib-induced invasion and migration might be due to senescence-associated secretory phenotype (SASP) rather than EMT and suggested that SASP could act as a potential target to potentiate the antitumor effects of palbociclib in cancer treatment.

ZNF750 exerted its Antitumor Action in Oral Squamous Cell Carcinoma by regulating E2F2

Cell cycle activator E2F transcription factor 2 (E2F2) play a key role in tumor development and metastasis. Previous RNA sequence analysis (GSE134835) revealed E2F2 was significantly reduced by Zinc-finger protein 750 (ZNF750) in oral squamous cell carcinoma (OSCC). This study was aimed to determine the involvement of E2F2 in antitumor action of ZNF750. The nude mouse xenograft model was established by subcutaneously injection of stable cell line CAL-27^oeZNF750 or CAL-27^shZNF750. Xenograft tumor volume and tumor weight was measured. The expression of E2F2, transcriptional repressors such as enhancer of zeste 2 (Ezh2), PHD finger protein 19 (PHF19), and the genes related to cell proliferation or metastasis was studied in vivo or in vitro. Luciferase assay was performed to investigate regulation effect of ZNF750 on E2F2 luciferase activity. The involvement of E2F2 in the antitumor action of ZNF750 was studied by cotransduced ZNF750 with E2F2 lentivirus. The tumor growth and metastasis was repressed by ZNF750 manifested by reduced tumor size, tumor weight and the genes related to cell proliferation and metastasis. However, all of these were reversed by knockdown of the ZNF750 gene. Furthermore, E2F2 luciferase activity was inhibited by ZNF750. E2F2 partly blocked the antitumor action of ZNF750 manifested by increased self-renewal, invasion, migration, elevated Ezh2 and MMP13 protein expression in ZNF750 + E2F2 groups. However, silenced E2F2 further enhanced the antitumor action of ZNF750. ZNF750 depressed E2F2 activity and played a critical role in regulating transcriptional repressors for inhibiting the OSCC growth and metastasis in OSCC.

PAX6 upstream antisense RNA (PAUPAR) inhibits colorectal cancer progression through modulation of the microRNA (miR)-17-5p / zinc finger protein 750 (ZNF750) axis

Researchers have demonstrated that long non-coding RNAs (lncRNAs) are vital in colorectal cancer (CRC) progression. Here, we aimed to explore the function of lncRNA PAX6 upstream antisense RNA (PAUPAR) in the development of CRC. In the present study, PAUPAR and microRNA (miR)-17-5p expression levels in CRC tissues and cells were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Western blot analysis was adopted to examine ZNF750 expression at the protein level in CRC cells. CRC cell proliferation was examined by colony formation experiment and 5-Bromo-2-deoxyUridine (BrdU) experiment. CRC cell migration and invasion were assessed by Transwell experiments. Apoptosis was measured using the TUNEL experiment. The targeting relationship between PAUPAR and miR-17-5p was confirmed using dual-luciferase reporter gene and RNA immunoprecipitation (RIP) experiments. We demonstrated that PAUPAR was markedly down-modulated in CRC, and its low expression was significantly related to increased T stage and local lymph node metastasis. Knockdown of PAUPAR enhanced CRC cell proliferation, migration and invasion, and restrained apoptosis relative to controls, whereas PAUPAR overexpression caused the opposite effects. Moreover, rescue experiments showed that miR-17-5p inhibitor could reverse the role of PAUPAR knockdown on the malignant phenotypes of CRC cells. Additionally, PAUPAR could positively regulate the expression of ZNF750 via repressing miR-17-5p. Taken together, these findings suggest that PAUPAR/miR-17-5p/ZNF750 axis is a novel mechanism implicated in CRC progression.

Construction and Validation of an Immune-Related Gene Prognostic Index for Esophageal Squamous Cell Carcinoma

Immune checkpoint inhibitor (ICI) therapy may benefit patients with advanced esophageal squamous cell carcinoma (ESCC); however, novel biomarkers are needed to help predict the response of patients to treatment. Differentially expressed immune-related genes within The Cancer Genome Atlas ESCC dataset were selected using the weighted gene coexpression network and lasso Cox regression analyses. Based on these data, an immune-related gene prognostic index (IRGPI) was constructed. The molecular characteristics of the different IRGPI subgroups were assessed using mutation information and gene set enrichment analysis. Differences in immune cell infiltration and the response to ICI therapy and other drugs were also analyzed. Additionally, tumor and adjacent control tissues were collected from six patients with ESCC and the expression of these genes was verified using real-time quantitative polymerase chain reaction. IRGPI was designed based on CLDN1, HCAR3, FNBP1L, and BRCA2, the expression of which was confirmed in ESCC samples. The prognosis of patients in the high-IRGPI group was poor, as verified using publicly available expression data. KMT2D mutations were more common in the high-IRGPI group. Enrichment analysis revealed an active immune response, and immune infiltration assessment showed that the high-IRGPI group had an increased infiltration degree of CD8 T cells, which contributed to the improved response to ICI treatment. Collectively, these data demonstrate that IRGPI is a robust biomarker for predicting the prognosis and response to therapy of patients with ESCC.

Site-specific glycoproteomic analysis revealing increased core-fucosylation on FOLR1 enhances folate uptake capacity of HCC cells to promote EMT

Rationale: Epithelial-mesenchymal transition (EMT) has been recognized as an important step toward high invasion and metastasis of many cancers including hepatocellular carcinoma (HCC), while the mechanism for EMT promotion is still ambiguous.

Methods: The dynamic alterations of site-specific glycosylation during HGF/TGF-β1-induced EMT process of three HCC cell lines were systematically investigated using precision glycoproteomic methods. The possible roles of EMT-related glycoproteins and site-specific glycans were further confirmed by various molecular biological approaches.

Results: Using mass spectrometry-based glycoproteomic methods, we totally identified 2306 unique intact glycopeptides from SMMC-7721 and HepG2 cell lines, and found that core-fucosylated glycans were accounted for the largest proportion of complex N-glycans. Through quantification analysis of intact glycopeptides, we found that the majority of core-fucosylated intact glycopeptides from folate receptor α (FOLR1) were up-regulated in the three HGF-treated cell lines. Similarly, core-fucosylation of FOLR1 were up-regulated in SMMC-7721 and Hep3B cells with TGF-β1 treatment. Using molecular approaches, we further demonstrated that FUT8 was a driver for HGF/TGF-β1-induced EMT. The silencing of FUT8 reduced core-fucosylation and partially blocked the progress of HGF-induced EMT. Finally, we confirmed that the level of core-fucosylation on FOLR1 especially at the glycosite Asn-201 positively regulated the cellular uptake capacity of folates, and enhanced uptake of folates could promote the EMT of HCC cells.

Conclusions: Based on the results, we proposed a potential pathway for HGF or TGF-β1-induced EMT of HCC cells: HGF or TGF-β1 treatment of HCC cells can increase the expression of glycosyltransferase FUT8 to up-regulate the core-fucosylation of N-glycans on glycoproteins including the FOLR1; core-fucosylation on FOLR1 can then enhance the folate uptake capacity to finally promote the EMT progress of HCC cells.

The PSMD14 inhibitor Thiolutin as a novel therapeutic approach for esophageal squamous cell carcinoma through facilitating SNAIL degradation

Metastasis and chemoresistance are major causes of poor prognosis in patients with esophageal squamous cell carcinoma (ESCC), manipulated by multiple factors including deubiquitinating enzyme (DUB). DUB PSMD14 is reported to be a promising therapeutic target in various cancers. Here, we explored the antitumor activity of Thiolutin (THL), the PSMD14 inhibitor, as a new therapy strategy in ESCC.

Methods: Through 4-NQO-induced murine ESCC model, we investigated the expression of PSMD14 in esophageal tumorigenesis. Ubiquitin-AMC assay was performed to evaluate DUB activity of PSMD14 with THL treatment. The effect of THL on epithelial-to-mesenchymal transition (EMT), invasion, stemness and chemosensitivity was detected by using in vitro and in vivo experiments. Immunoprecipitation and in vivo ubiquitination assay were conducted to examine whether THL could impair the deubiquitination and stability of SNAIL regulated by PSMD14.

Results: Compared with normal esophageal epithelium, PSMD14 was upregulated in 4-NQO-induced murine esophageal epithelium dysplasia and ESCC tissues. THL could significantly weaken DUB activity of PSMD14. Furthermore, the results of in vitro and in vivo assays showed that THL efficiently suppressed motility and stemness and increased sensitivity to cisplatin in ESCC. Mechanically, THL impaired the interaction between PSMD14 and SNAIL, then promoted the ubiquitination and degradation of SNAIL to inhibit EMT which plays a crucial role in ESCC metastasis, stemness and chemosensitivity. TCGA database analysis revealed that high concomitant PSMD14/SNAIL expression predicted shorter overall survival in esophageal cancer.

Conclusion: Our findings demonstrate for the first time that suppression of PSMD14/SNAIL axis by THL could be a novel and promising therapeutic approach for ESCC clinical therapy.

Polygalacin D suppresses esophageal squamous cell carcinoma growth and metastasis through regulating miR-142-5p/Nrf2 axis

Esophageal squamous cell carcinoma (ESCC) is a common malignancy worldwide with poor survival. High expression of nuclear factor erythroid 2-related factor 2 (Nrf2) is an antioxidant transcript factor that protects malignant cells from death. Polygalacin D (PGD), a bioactive compound isolated from Platycodongrandiflorum (Jacq.), has recently been reported to be an anti-tumor agent. This study aimed to investigate the anti-cancer effects of PGD and its underlying molecular mechanisms in human ESCC. Here, we confirmed that Nrf2 was over-expressed in clinical ESCC tissues and cell lines. PGD treatments markedly reduced Nrf2 expression in a dose- and time-dependent manner in ESCC cell lines. Importantly, we found that PGD significantly reduced proliferation, and induced G2/M cell cycle arrest and apoptosis in ESCC cells. Also, PGD dramatically triggered autophagy in ESCC cells, and autophagy inhibitor bafilomycinA1 (BafA1) greatly abrogated the inhibitory role of PGD in cell viability and apoptosis. In addition, PGD evidently provoked reactive oxygen species (ROS) accumulation in ESCC cells, and pre-treatment of ROS scavenger N-acetyl-l-cysteine (NAC) markedly abolished PGD-triggered cell death. PGD also dramatically repressed migration and invasion in ESCC cells. Mechanistic investigation revealed that Nrf2 gene was directly targeted by miR-142-5p. MiR-142-5p negatively regulated Nrf2 expression in ESCC cells. We notably found that PGD-inhibited proliferation, migration and invasion in ESCC were considerably rescued by miR-142-5p knockdown; however, ROS production, apoptosis and autophagy induced by PGD were almost eliminated when miR-142-5p was silenced. On the contrast, over-expressing miR-142-5p could remarkably promote the anti-ESCC effects of PGD. Experiments in vivo by the tumor xenograft model confirmed that miR-142-5p effectively improved the activity of PGD to repress tumor growth and lung metastasis. Both in vitro and in vivo studies showed that PGD had few side effects on normal cells and major organs. Collectively, our findings provided the first evidence that PGD could be an effective therapeutic strategy for ESCC treatment by regulating miR-142-5p/Nrf2 axis with few adverse effects.

PURα Promotes the Transcriptional Activation of PCK2 in Oesophageal Squamous Cell Carcinoma Cells

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal gastrointestinal malignancies due to its characteristics of local invasion and distant metastasis. Purine element binding protein α (PURα) is a DNA and RNA binding protein, and recent studies have showed that abnormal expression of PURα is associated with the progression of some tumors, but its oncogenic function, especially in ESCC progression, has not been determined. Based on the bioinformatic analysis of RNA-seq and ChIP-seq data, we found that PURα affected metabolic pathways, including oxidative phosphorylation and fatty acid metabolism, and we observed that it has binding peaks in the promoter of mitochondrial phosphoenolpyruvate carboxykinase (PCK2). Meanwhile, PURα significantly increased the activity of the PCK2 gene promoter by binding to the GGGAGGCGGA motif, as determined though luciferase assay and ChIP-PCR/qPCR. The results of Western blotting and qRT-PCR analysis showed that PURα overexpression enhances the protein and mRNA levels of PCK2 in KYSE510 cells, whereas PURα knockdown inhibits the protein and mRNA levels of PCK2 in KYSE170 cells. In addition, measurements of the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) indicated that PURα promoted the metabolism of ESCC cells. Taken together, our results help to elucidate the molecular mechanism by which PURα activates the transcription and expression of PCK2, which contributes to the development of a new therapeutic target for ESCC.