Comparison of metastasis and prognosis between early-onset and late-onset hepatocellular carcinoma: A population-based study.

Background: While hepatocellular carcinoma (HCC) represents a highly heterogeneous disease with variable oncogenesis mechanisms and biological features, little is understood about differences in distant metastasis (DM) and prognosis between early-onset and late-onset HCC. This study defined early-onset disease as cancer diagnosed at age younger than 50 years and aimed to present a comprehensive analysis to characterize these disparities based on age. Methods: Information of HCC patients was retrospectively collected from the SEER database and our hospital. Patient demographics, tumor characteristics, and survival were compared between the two groups. A 1:1 propensity score matching (PSM) was adopted to adjust confounding factors. Logistic and cox analysis were utilized to explore risk factors of DM and prognosis, respectively. Besides, the survival differences were assessed by the Kaplan-Meier curve and log-rank test. Results: In total, 19187 HCC patients obtained from the SEER database and 129 HCC patients obtained from our own center were enrolled. Among 19187 patients with HCC, 3376 were identified in the matched cohort, including 1688 early-onset patients and 1688 late-onset patients. Compared with late-onset HCC, early-onset HCC was more likely to occur in female (25.2% vs. 22.9%, P = 0.030), have large tumors (>10.0 cm, 24.1% vs. 14.6%, P = 0.000), harbor poorly differentiated/undifferentiated cancers (17.0% vs. 14.0%, P = 0.003), present advanced clinical stage (T3+T4, 33.7% vs. 28.5%; N1, 9.2% vs. 6.7%; P = 0.000), and develop DM (13.0% vs. 9.5%, P = 0.000). After adjustment for confounders by PSM, we discovered that early-onset HCC remained an independent risk factor for DM. However, combined with Kaplan-Meier curve and cox analysis, early-onset HCC was an independent favorable predictor of survival. We validated these data on an independent cohort from our hospital. Conclusion: In this population-based study, despite developing DM more frequently, early-onset HCC exhibited a superior prognosis than late-onset HCC. Nevertheless, further research is warranted to understand the underlying aetiologic basis for the disparities.

O-GlcNAcylation promotes the progression of nonalcoholic fatty liver disease by upregulating the expression and function of CD36.

BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) and its progressive variant, nonalcoholic steatohepatitis (NASH), constitute a burgeoning worldwide epidemic with no FDA-approved pharmacotherapies. The multifunctional immunometabolic receptor, fatty acid translocase CD36 (CD36), plays an important role in the progression of hepatic steatosis. O-GlcNAcylation is a crucial posttranslational modification that mediates the distribution and function of CD36, but its involvement in NAFLD remains poorly understood. METHODS: O-GlcNAcylation and CD36 expression were evaluated in human liver tissues obtained from NASH patients and normal control. Mice with hepatocyte-specific CD36 knockout were administered adeno-associated viral vectors expressing wild-type CD36 (WT-CD36) or CD36 O-GlcNAcylation site mutants (S468A&T470A-CD36) and were provided with a high-fat/high-cholesterol (HFHC) diet for 3 months. RT-qPCR analysis, immunoblotting, dual-luciferase reporter assays, chromatin immunoprecipitation, and coimmunoprecipitation were performed to explore the mechanisms by which O-GlcNAcylation regulates CD36 expression. Membrane protein extraction, immunofluorescence analysis, site-directed mutagenesis, and fatty acid uptake assays were conducted to elucidate the impact of O-GlcNAcylation on CD36 function. RESULTS: O-GlcNAcylation and CD36 expression were significantly increased in patients with NASH, mouse models of NASH, and palmitic acid-stimulated hepatocytes. Mechanistically, the increase in O-GlcNAcylation facilitated the transcription of CD36 via the NF-κB signalling pathway and stabilized the CD36 protein by inhibiting its ubiquitination, thereby promoting CD36 expression. On the other hand, O-GlcNAcylation facilitated the membrane localization of CD36, fatty acid uptake, and lipid accumulation. However, site-directed mutagenesis of residues S468 and T470 of CD36 reversed these effects. Furthermore, compared with their WT-CD36 counterparts, HFHC-fed S468A&T470A-CD36 mice exhibited decreases in systemic insulin resistance, steatosis severity, inflammation and fibrosis. Pharmacological inhibition of O-GlcNAcylation and CD36 also mitigated the progression of NASH. CONCLUSIONS: O-GlcNAcylation promotes the progression of NAFLD by upregulating CD36 expression and function. Inhibition of CD36 O-GlcNAcylation protects against NASH, highlighting a potentially effective therapeutic approach for individuals with NASH.

Protective and Adverse Roles of DDX3X in Different Cell Types in Nonalcoholic Steatohepatitis Progression.

Persistent hepatic cellular metabolic stress and liver inflammatory stimuli are key signatures of nonalcoholic steatohepatitis (NASH). DDX3X is a vital molecule involved in cell fate decisions in both pro-survival stress granule (SG) and pro-death NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome assembly in response to stress signals. However, the role of DDX3X in NASH remains unclear. We characterized the cell type-specific roles of DDX3X in NASH. Human liver tissues from NASH patients and normal control subjects were collected to assess DDX3X expression and distribution. Nutritional steatohepatitis models were constructed by feeding macrophage-specific DDX3X knockout (DDX3XΔMφ), hepatocyte-specific DDX3X knockout (DDX3XΔhep), and wild-type control (DDX3Xfl/fl) mice a high-fat and high-cholesterol (HFHC) diet, a methionine- and choline-deficient (MCD) diet, and a high-fat/high-iron/high-fructose/high-cholesterol, low-methionine, and choline-deficient (HFHIHFHC-MCD) diet. The study demonstrated that DDX3X was predominantly expressed in macrophages and hepatocytes in control liver tissues, and its expression was down-regulated in patients or mice with NASH. Compared to DDX3Xfl/fl littermates, DDX3XΔMφ mice showed improved liver histology in nutritional steatohepatitis models. Loss of macrophage DDX3X inhibited NLRP3 inflammasome-mediated pyroptosis, causing anti-inflammatory M2 polarization and alleviating hepatocyte steatohepatitic changes. DDX3XΔhep mice developed marked steatohepatitis in multiple nutritional steatohepatitis models compared to DDX3Xfl/fl littermates. DDX3X-deleted hepatocytes showed impaired SG assembly, leading to increased sensitivity and intolerance to metabolic stimulation and resultant steatohepatitis. In conclusion, DDX3X plays opposite roles in different cell types during the progression of NASH. A better understanding of the cell-specific differences in the crosstalk between SG formation and NLRP3 activation is crucial for developing prospective targeted DDX3X inhibitors for the treatment of NASH.

Hepatocyte DDX3X protects against drug-induced acute liver injury via controlling stress granule formation and oxidative stress.

Drug-induced liver injury (DILI) is the leading cause of acute liver failure (ALF). Continuous and prolonged hepatic cellular oxidative stress and liver inflammatory stimuli are key signatures of DILI. DEAD-box helicase 3, X-linked (DDX3X) is a central regulator in pro-survival stress granule (SG) assembly in response to stress signals. However, the role of DDX3X in DILI remains unknown. Herein, we characterized the hepatocyte-specific role of DDX3X in DILI. Human liver tissues of DILI patients and control subjects were used to evaluate DDX3X expression. APAP, CCl4 and TAA models of DILI were established and compared between hepatocyte-specific DDX3X knockout (DDX3XΔhep) and wild-type control (DDX3Xfl/fl) mice. Hepatic expression of DDX3X was significantly decreased in the pathogenesis of DILI compared with controls in human and mice. Compared to DDX3Xfl/fl mice, DDX3XΔhep mice developed significant liver injury in multiple DILI models. DDX3X deficiency aggravates APAP induced oxidative stress and hepatocyte death by affecting the pro-survival stress granule (SG) assembly. Moreover, DDX3X deficiency induces inflammatory responses and causes pronounced macrophage infiltration. The use of targeted DDX3X drug maybe promising for the treatment of DILI in human.

TAF15 exacerbates nonalcoholic steatohepatitis progression by regulating lipid metabolism and inflammation via FASN and p65 NF-κB.

BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) consists of a broad spectrum of conditions, and nonalcoholic steatohepatitis (NASH) is the advanced form of NAFLD. TAF15 is a DNA and RNA binding protein and is involved in crucial inflammatory signalling pathways. We aimed to investigate the role of TAF15 in the progression of NASH and the underlying molecular mechanism. METHODS: We generated mice with hepatocyte-specific knockdown and overexpression of TAF15 using a specific adeno-associated virus (AAV). NASH models were established by feeding mice high-fat and high-cholesterol diets and methionine- and choline-deficient diets. Cleavage under targets and tagmentation and dual-luciferase reporter assays were performed to investigate the effect of TAF15 on FASN transcription. Coimmunoprecipitation and immunofluorescence assays were conducted to explore the interaction of TAF15 and p65. In vitro coculture systems were established to study the interactions of hepatocytes, macrophages and HSCs. RESULTS: TAF15 was significantly increased in the livers of mouse NASH models and primary hepatocyte NASH model. Knockdown of TAF15 inhibited steatosis, inflammation and fibrosis, while overexpression of TAF15 promoted NASH phenotypes. Mechanistically, TAF15 bound directly to the promoter region of FASN to facilitate its expression, thereby promoting steatosis. Moreover, TAF15 interacted with p65 and activated the NF-κB signalling pathway, increasing the secretion of proinflammatory cytokines and triggering M1 macrophage polarization. Treatment with the FASN inhibitor orlistat partially reversed the phenotypes. CONCLUSIONS: These results suggested that TAF15 exacerbated NASH progression by regulating lipid metabolism and inflammation via transcriptional activation of FASN and interacting with p65 to activate the NF-κB signalling pathway.

Endoplasmic reticulum-resident protein Sec62 drives colorectal cancer metastasis via MAPK/ATF2/UCA1 axis.

OBJECTIVE: Metastasis is responsible for the poor prognosis of patients with colorectal cancer (CRC), and the role of aberrant expression of endoplasmic reticulum (ER) receptors in tumour metastasis has not been fully elucidated. The aim of the study is to ensure the role of ER-resident protein Sec62 in CRC metastasis and illuminate associated molecular mechanisms. MATERIALS AND METHODS: Bioinformatics analysis, qRT-PCR, western blot and immunohistochemistry assays were performed to evaluate the expression level and clinical significance of Sec62 in CRC. The specific role of Sec62 in CRC was identified by a series of functional experiments. We conducted RNA sequencing and rescue experiments to analyse the differentially expressed genes and identified UCA1 as a novel pro-metastasis target of Sec62 in CRC. Besides, the efficacy of MAPK/JNK inhibitor or agonist on Sec62-mediated CRC metastasis was evaluated by trans-well and wound healing assays. Finally, luciferase reporter and ChIP assay were employed to further explore the potential mechanisms. RESULTS: The abnormally elevated expression of Sec62 predicted poor prognosis of CRC patients and facilitated malignant metastasis of CRC cells. Mechanistically, Sec62 enhanced UCA1 expression through activating MAPK/JNK signalling pathway. And the p-JNK activating ATF2 could transcriptionally regulate UCA1 expression. Furthermore, blocking or activating MAPK/JNK signalling with JNK inhibitor or agonist potently suppressed or enhanced Sec62 mediated CRC metastatic process. CONCLUSIONS: Our study reports for the first time that the Sec62/MAPK/ATF2 /UCA1 axis exists in CRC metastatic process, which could be a potential treatment target of metastatic CRC.

Long noncoding RNA LINC00239 inhibits ferroptosis in colorectal cancer by binding to Keap1 to stabilize Nrf2.

Ferroptosis, a novel regulated cell death induced by iron-dependent lipid peroxidation, plays an important role in tumor development and drug resistance. Long noncoding RNAs (lncRNAs) are associated with various types of cancer. However, the precise roles of many lncRNAs in tumorigenesis remain elusive. Here we explored the transcriptomic profiles of lncRNAs in primary CRC tissues and corresponding paired adjacent non-tumor tissues by RNA-seq and found that LINC00239 was significantly overexpressed in colorectal cancer tissues. Abnormally high expression of LINC00239 predicts poorer survival and prognosis in colorectal cancer patients. Concurrently, we elucidated the role of LINC00239 as a tumor-promoting factor in CRC through in vitro functional studies and in vivo tumor xenograft models. Importantly, overexpression of LINC00239 decreased the anti-tumor activity of erastin and RSL3 by inhibiting ferroptosis. Collectively, these data suggest that LINC00239 plays a novel and indispensable role in ferroptosis by nucleotides 1-315 of LINC00239 to interact with the Kelch domain (Nrf2-binding site) of Keap1, inhibiting Nrf2 ubiquitination and increasing Nrf2 protein stability. Considering the recurrence and chemoresistance constitute the leading cause of death in colorectal cancer (CRC), ferroptosis induction may be a promising therapeutic strategy for CRC patients with low LINC00239 expression.

Tubulin-binding peptide RR-171 derived from human umbilical cord serum displays antitumor activity against hepatocellular carcinoma via inducing apoptosis and activating the NF-kappa B pathway.

OBJECTIVES: Hepatocellular carcinoma (HCC) still presents a high incidence of malignant tumours with poor prognosis. There is an urgent need for new therapeutic agents with high specificity, low toxicity and favourable solubility for the clinical treatment of HCC. MATERIALS AND METHODS: The bioactivity of human umbilical cord serum was investigated by proteomics biotechnology and a primitive peptide with certain biological activity was identified. The antitumour effect of RR-171 was detected by cell viability assay in vitro, and determined by subcutaneous xenograft models assay and miniPDX assay in vivo. Pull-down experiments were conducted to identify the potential targeting proteins of RR-171. Immunofluorescence assay and tubulin polymerization assay were conducted to explore the relationship between RR-171 and α-tubulin. Fluorescence imaging in xenograft models was used to explore the biodistribution of RR-171 in vivo. A phosphospecific protein microarray was performed to uncover the underlying signalling pathway by which RR-171 induces tumour cell death. RESULTS: The results indicated that RR-171 could be effective in the treatment of HCC in vivo and in vitro. RR-171 could aggregate significantly in solid tumours and had no obvious systemic toxicity in vivo. RR-171 could interact with α-tubulin and activate the NF-Kappa B pathway in HCC cells. CONCLUSIONS: Taken together, RR-171 exhibited significant antitumour activity against HCC in vivo and in vitro and could potentially be used in the clinical application of HCC.

Development and validation of prognostic nomograms for patients with metastatic small bowel adenocarcinoma: a retrospective cohort study.

We aimed to explore factors associated with prognosis in patients with metastatic small bowel adenocarcinoma (SBA) as well as to develop and validate nomograms to predict overall survival (OS) and cancer-specific survival (CSS). Relevant information of patients diagnosed between 2004 and 2016 was extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Nomograms for predicting 1- and 3-year OS and CSS were established with potential risk factors screened from multivariate cox regression analysis. The discrimination and accuracy of the nomograms were assessed by concordance index (C-index), calibration plots, and the area under receiver operating characteristic curve (AUC). In total, 373 SBA patients with M1 category were enrolled. Multivariate analysis revealed that age, size and grade of primary tumor, primary tumor surgery, and chemotherapy were significant variables associated with OS and CSS. The C-index values of the nomogram for OS were 0.715 and 0.687 in the training and validation cohorts, respectively. For CSS, it was 0.711 and 0.690, respectively. Through AUC, decision curve analysis (DCA) and calibration plots, the nomograms displayed satisfactory prognostic predicted ability and clinical application both in the OS and CSS. Our models could be served as a reliable tool for prognostic evaluation of patients with metastatic SBA, which are favorable in facilitating individualized survival predictions and clinical decision-making.

Sec62 promotes gastric cancer metastasis through mediating UPR-induced autophagy activation.

BACKGROUND AND AIMS: Sec62 is a membrane protein of the endoplasmic reticulum that facilitates protein transport. Its role in cancer is increasingly recognised, but remains largely unknown. We investigated the functional role of Sec62 in gastric cancer (GC) and its underlying mechanism. METHODS: Bioinformatics, tissue microarray, immunohistochemistry (IHC), western blotting (WB), quantitative polymerase chain reaction (qPCR), and immunofluorescence were used to examine the expression of target genes. Transwell, scratch healing assays, and xenograft models were used to evaluate cell migration and invasion. Transmission electron microscopy and mRFP-GFP-LC3 double-labeled adenoviruses were used to monitor autophagy. Co-immunoprecipitation (CO-IP) was performed to evaluate the binding activity between the proteins. RESULTS: Sec62 expression was upregulated in GC, and Sec62 upregulation was an independent predictor of poor prognosis. Sec62 overexpression promoted GC cell migration and invasion both in vitro and in vivo. Sec62 promoted migration and invasion by affecting TIMP-1 and MMP2/9 balance. Moreover, Sec62 could activate autophagy by upregulating PERK/ATF4 expression and binding to LC3II with concomitant FIP200/Beclin-1/Atg5 activation. Furthermore, autophagy blockage impaired the promotive effects of Sec62 on GC cell migration and invasion, whereas autophagy activation rescued the inhibitory effect of Sec62 knockdown on GC metastasis. Notably, Sec62 inhibition combined with autophagy blockage exerted a synergetic anti-metastatic effect in vitro and in vivo. CONCLUSION: Sec62 promotes GC metastasis by activating autophagy and subsequently regulating TIMP-1 and MMP2/9 balance. The activation of autophagy by Sec62 may involve the unfolded protein response (UPR)-related PERK/ATF4 pathway and binding of LC3II during UPR recovery involving FIP200/Beclin-1/Atg5 upregulation. Specifically, the dual inhibition of Sec62 and autophagy may provide a promising therapeutic strategy for GC metastasis.

Proteomic analysis of human umbilical cord serum exosomes using mass spectrometry and preliminary study of their biological activities in liver cancer cell lines.

Exosomes are membranous extracellular vesicles 50-100 nm in size, which are involved in cellular communication via the delivery of proteins, lipids and RNA. Emerging evidence shows that exosomes play a critical role in cancer. It has recently been revealed that maternal and umbilical cord serum (UCS)-derived exosomes may enhance endothelial cell proliferation and migration. However, the role of exosomes isolated from the human umbilical cord in cancer development has not been investigated. To explore the potential differences in the composition and function of proteins from umbilical serum exosomes (UEs) and maternal serum exosomes, a proteomic analysis of exosomes was conducted using mass spectrometry and bioinformatics. Moreover, Cell Counting Kit-8 assays and flow cytometry were used to study the biological effects of UEs on liver cancer cell lines. The present study demonstrated that UCS was enriched with proteins involved in extracellular matrix-receptor interactions, which may be closely related to cell metastasis and proliferation. The findings further indicated that exosomes derived from human umbilical serum could inhibit the viability and induce apoptosis of liver cancer cells. This suggests that UCS-derived exosomes may represent potential leads for the development of biotherapy for liver cancer.

ETV4 promotes pancreatic ductal adenocarcinoma metastasis through activation of the CXCL13/CXCR5 signaling axis.

Pancreatic ductal adenocarcinoma (PDAC) has the highest fatality rate of any solid tumor, with a five-year survival rate of only 10% in the USA. PDAC is characterized by early metastasis. More than 50% of patients present with distant metastases at the time of diagnosis, and the majority of patients will develop metastasis within 4 years after tumor resection. Despite extensive studies, the molecular mechanisms underlying PDAC metastasis remain unclear. The polyoma enhancer activator protein (PEA3) subfamily was reported to play a vital role in the initiation and progression of multiple tumors. Herein, we found that ETS variant 4 (ETV4) was highly expressed in PDAC tissues and associated with poor survival. Univariate and multivariate analyses revealed that ETV4 expression was an independent prognostic factor for patient survival. Further experiments showed that ETV4 overexpression promoted PDAC invasion and metastasis both in vitro and in vivo. For the first time, we demonstrated that, mechanistically, ETV4 increased CXCR5 expression by directly binding to the CXCR5 promoter region. Knockdown of CXCR5 significantly reversed ETV4-mediated PDAC migration and invasion, while CXCR5 overexpression exerted the opposite effects. Intriguingly, we found that CXCL13, a specific ligand of CXCR5, increased ETV4 expression and promoted PDAC invasion and metastasis by activating the ERK1/2 pathway. ETV4 knockdown significantly abrogated the enhanced migratory and invasive abilities induced by the CXCL13/CXCR5 axis. In addition, a CXCR5 neutralizing antibody disrupted the CXCL13/ETV4/CXCR5 positive feedback loop and inhibited cell migration and invasion. Overall, in this study, we demonstrated that ETV4 plays a vital role in PDAC metastasis and defined a novel CXCL13/ETV4/CXCR5 positive feedback loop. Targeting this pathway has implications for potential therapeutic strategies for PDAC treatment.

Timing of endoscopic intervention in patients with cirrhosis with acute variceal haemorrhage (TEACH trial): protocol for a randomised clinical trial (RCT).

INTRODUCTION: Acute variceal haemorrhage (AVH) in patients with cirrhosis remains a topic of great interest. Although several guidelines recommend endoscopy within 24 hours after AVH, there is no consensus on the most appropriate time to perform this intervention. The purpose of this study is to identify whether urgent endoscopy (within 6 hours after gastroenterological consultation) is superior to non-urgent endoscopy (between 6 hours and 24 hours after gastroenterological consultation) in reducing the rebleeding rate of these patients. METHODS AND ANALYSIS: This is a single-centred, prospective, randomised clinical trial. Between March 2021 and December 2023, an estimated 400 patients will be randomised in a 1:1 ratio to receive endoscopic intervention either within 6 hours or between 6 and 24 hours after gastroenterological consultation. Randomisation will be conducted by permuted block randomisation, with stratification by age, systolic blood pressure and pulse rate. The primary efficacy endpoint is rebleeding within 42 days after control of AVH. The secondary efficacy endpoints mainly include all-cause mortality within 42 days after randomisation, persistent bleeding, length of hospitalisation, etc. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethical Committees of Jinling Hospital (authorised ethics no. DZQH-KYLL-21-01). This trial will provide valuable insights into the timing of endoscopic intervention for AVH in patients with cirrhosis. Furthermore, the trial results and conclusions could provide high-quality evidence to guide clinical research and treatment. TRIAL REGISTRATION NUMBER: NCT04786743.

Prediction of overall survival in patients with Stage I esophageal cancer: A novel web-based calculator.

BACKGROUND AND AIMS: In this study, we aimed to develop a convenient web-based calculator to predict the overall survival (OS) of patients with Stage I esophageal cancer (EC). METHODS: Data of 1664 patients, between 2004 and 2015, were extracted from the Surveillance, Epidemiology, and End Results database. Least absolute shrinkage and selection operator regression was employed to sift variables; subsequently, Cox proportional hazards regression model was built. We applied the enhanced bootstrap validation to appraise the discrimination and calibration of the model. Clinical benefit was measured using decision curve analysis (DCA). Thereafter, a web-based calculator based on the model, which could be used to predict the 1-, 3-, and 5-year OS rates, was developed. RESULTS: Race, age, histologic type, grade, N stage, and therapeutic methods were selected. C-indices of the prediction model in the training and validation groups were 0.726 (95% confidence interval [CI], 0.679-0.773) and 0.724 (95% CI, 0.679-0.769), respectively. Calibration curves showed good agreement between the groups. The DCA demonstrated that the prediction model is clinically useful. CONCLUSIONS: The prediction model we developed showed a good performance in calculating the OS rates in patients with Stage I EC. The web-based calculator is available at https://championship.shinyapps.io/dynnomapp/.

ARL4C might serve as a prognostic factor and a novel therapeutic target for gastric cancer: bioinformatics analyses and biological experiments.

The ADP-ribosylation factor-like proteins (ARLs) have been proved to regulate the malignant phenotypes of several cancers. However, the exact role of ARLs in gastric cancer (GC) remains elusive. In this study, we systematically investigate the expression status, interactive relations, potential pathways, genetic variations and clinical values of ARLs in GC. We find that ARLs are significantly dysregulated in GC and involved in various cancer-related pathways. Subsequently, machine learning models identify ARL4C as one of the two most significant clinical indicators among ARLs for GC. Furthermore, ARL4C silencing remarkably inhibits the growth and metastasis of GC cells both in vitro and in vivo. Moreover, enrichment analysis indicates that ARL4C is highly correlated with TGF-ß1 signalling. Correspondingly, TGF-ß1 treatment dramatically increases ARL4C expression and ARL4C knockdown inhibits the phosphorylation level of Smads, downstream factors of TGF-ß1. Meanwhile, the coexpression of ARL4C and TGF-ß1 worsens the prognosis of GC patients. Our work comprehensively demonstrates the crucial role of ARLs in the carcinogenesis of GC and the specific mechanisms underlying the GC-promoting effects of TGF-ß1. More importantly, we uncover the great promise of ARL4C-targeted therapy in improving the efficacy of TGF-ß1 inhibitors for GC patients.

LINC00941 promotes CRC metastasis through preventing SMAD4 protein degradation and activating the TGF-ß/SMAD2/3 signaling pathway.

ABSTRICT: LINC00941 is a novel lncRNA that has been found to exhibit protumorigenic and prometastatic behaviors during tumorigenesis. However, its role in metastatic CRC remains unknown. We aimed to investigate the functions and mechanisms of LINC00941 in CRC metastasis. LINC00941 was shown to be upregulated in CRC, and upregulated LINC00941 was associated with poor prognosis. Functionally, LINC00941 promoted migratory and invasive capacities and accelerated lung metastasis in nude mice. Mechanistically, LINC00941 activated EMT in CRC cells, as indicated by the increased expression of key molecular markers of cell invasion and metastasis (Vimentin, Fibronectin, and Twist1) and simultaneous decreased expression of the main invasion suppressors E-cadherin and ZO-1. LINC00941 was found to activate EMT by directly binding the SMAD4 protein MH2 domain and competing with ß-TrCP to prevent SMAD4 protein degradation, thus activating the TGF-ß/SMAD2/3 signaling pathway. Our data reveal the essential role of LINC00941 in metastatic CRC via activation of the TGF-ß/SMAD2/3 axis, which provides new insight into the mechanism of metastatic CRC and a novel potential therapeutic target for advanced CRC.

O-GlcNAcylation of SIX1 enhances its stability and promotes Hepatocellular Carcinoma Proliferation.

It is universally accepted that aberrant metabolism facilitates tumor growth. However, how cancer cells coordinate glucose metabolism and tumor proliferation is largely unknown. Sine oculis homeobox homolog 1 (SIX1) is a transcription factor that belongs to the SIX family and is believed to play an important role in the regulation of the Warburg effect in tumors. However, whether the role of SIX1 and the molecular mechanisms that regulate its activity are similar in hepatocellular carcinoma (HCC) still needs further investigation. Methods: Western blotting was performed to determine the levels of SIX1 and O-linked ß-N-acetylglucosaminylation (O-GlcNAcylation) in HCC tissues. Cell Counting Kit 8 (CCK8), colony formation and mouse tumor model assays were used to establish the role of SIX1 and O-GlcNAcylation in HCC processes. Mass spectrometry, immunoprecipitation and site-directed mutagenesis were performed to confirm the O-GlcNAcylation of SIX1. Results: Here, we demonstrated that SIX1, the key transcription factor regulating the Warburg effect in cancer, promotes HCC growth in vitro and in vivo. Furthermore, we revealed that SIX1 could also enhance the levels of a posttranslational modification called O-GlcNAcylation. Importantly, we found that SIX1 was also highly modified by O-GlcNAcylation and that O-GlcNAcylation inhibited the ubiquitination degradation of SIX1. In addition, site-directed mutagenesis at position 276 (T276A) decreased the O-GlcNAcylation level and reversed the protumor effect of SIX1. Conclusions: We conclude that O-GlcNAcylation of SIX1 enhances its stability and promotes HCC proliferation. Our findings illustrate a novel feedback loop of SIX1 and O-GlcNAcylation and show that O-GlcNAcylation of SIX1 is an important way to coordinate glucose metabolism and tumor progression.

SOX13 promotes colorectal cancer metastasis by transactivating SNAI2 and c-MET.

Metastasis is a major cause of high recurrence and poor survival of patients with colorectal cancer (CRC), although the mechanisms associated with this process remain poorly understood. In this study, we report a novel mechanism by which SOX13 promotes CRC metastasis by transactivating SNAI2 and c-MET. SOX13 overexpression was significantly correlated with more aggressive clinicopathological features of CRC and indicated poor prognosis in two independent cohorts of CRC patients (cohort I, n = 363; cohort II, n = 390). Overexpression of SOX13-promoted CRC migration, invasion, and metastasis, whereas SOX13 downregulation caused the opposite effects. Further mechanistic investigation identified SNAI2 and MET as important target genes of SOX13 using serial deletion and site-directed mutagenesis luciferase reporter and chromatin immunoprecipitation (ChIP) assays, as well as functional complementation analyses. In addition, SOX13 was shown to be a direct target of HGF/STAT3 signaling, and the c-MET inhibitor crizotinib blocked the HGF/STAT3/SOX13/c-MET axis, significantly inhibiting SOX13-mediated CRC migration, invasion and metastasis. Moreover, in clinical CRC tissues, SOX13 expression was positively correlated with the expression of SNAI2, c-MET, and HGF. CRC patients with positive coexpression of SOX13/SNAI2, SOX13/c-MET, or HGF/SOX13 exhibited a worse prognosis. In summary, SOX13 is a promising prognostic biomarker in patients with CRC, and blocking the HGF/STAT3/SOX13/c-MET axis with crizotinib could be a new therapeutic strategy to prevent SOX13-mediated CRC metastasis.

Dysbindin promotes pancreatic ductal adenocarcinoma metastasis by activating NF-κB/MDM2 via miR-342-3p.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most invasive solid tumours and has the highest cancer-related mortality rate. Despite intense investigation, the molecular mechanisms underlying the invasiveness and aetiology of PDAC remain elusive. MicroRNAs (miRNAs) are key regulators of tumour cell plasticity, but their roles in PDAC metastasis have not been characterized. Our early studies showed that dysbindin protein levels are elevated in PDAC patients compared with control individuals and that dysbindin upregulation elicits PDAC cell proliferation via the PI3K pathway. Here, we show that dysbindin promoted PDAC metastasis via the NF-κB/MDM2 signalling axis. Increased dysbindin levels correlated with aggressive features in PDAC, and the overexpression of dysbindin significantly promoted PDAC metastasis and invasion in vitro and in vivo. Surprisingly, dysbindin was identified as a direct target of miR-342-3p, which promotes NF-κB activation and PDAC metastasis. Thus, dysbindin-mediated NF-κB activation via miR-342-3p represents a context-dependent switch that enables PDAC cell proliferation and metastasis. Our data suggest that dysbindin and miR-342-3p are potential leads for the development of targeted therapy for PDAC.

O-GlcNAcase targets pyruvate kinase M2 to regulate tumor growth.

Cancer cells are known to adopt aerobic glycolysis in order to fuel tumor growth, but the molecular basis of this metabolic shift remains largely undefined. O-GlcNAcase (OGA) is an enzyme harboring O-linked ß-N-acetylglucosamine (O-GlcNAc) hydrolase and cryptic lysine acetyltransferase activities. Here, we report that OGA is upregulated in a wide range of human cancers and drives aerobic glycolysis and tumor growth by inhibiting pyruvate kinase M2 (PKM2). PKM2 is dynamically O-GlcNAcylated in response to changes in glucose availability. Under high glucose conditions, PKM2 is a target of OGA-associated acetyltransferase activity, which facilitates O-GlcNAcylation of PKM2 by O-GlcNAc transferase (OGT). O-GlcNAcylation inhibits PKM2 catalytic activity and thereby promotes aerobic glycolysis and tumor growth. These studies define a causative role for OGA in tumor progression and reveal PKM2 O-GlcNAcylation as a metabolic rheostat that mediates exquisite control of aerobic glycolysis.