F2RL3 Regulates Epithelial-Mesenchymal Transition and Angiogenesis in Gastric Cancer through the Rap1/MAPK Signaling Pathway.

BACKGROUND: Gastric cancer (GC) is frequently diagnosed at advanced stages, when cancer cells have already metastasized. Therefore, patients with GC have a low survival rate and poor prognosis even after treatment. METHODS: We downloaded GC-related RNA sequencing (RNA-Seq) data, copy number variation (CNV) data, and clinical data for bioinformatics analysis to screen prognostic genes of GC. Single-sample gene set enrichment analysis and survival analyses were performed on the RNA-Seq data, and differential and correlation analyses were conducted on the CNV data to obtain CNV-driven differentially expressed genes (DEGs). Prognostic genes were identified through univariate Cox analyses of the CNV-driven DEGs, combined with the clinical data. F2R like thrombin or trypsin receptor 3 (F2RL3) was finally selected for verification after functional and survival analyses of the prognostic genes. RESULTS: F2RL3 expression was lower in paracancer tissue than in GC tissue, and lower in GES-1 gastric epithelial cells than in GC cells. The cell culture supernatants from F2RL3-knockdown GC cells were collected and used to culture human umbilical vein endothelial cells (HUVECs). It was observed that F2RL3 enhanced the activity, metastasis, invasion, and angiogenesis of GC cells; promoted the epithelial-mesenchymal transition (EMT) of GC cells; and impacted the Ras-associated protein 1 (Rap1)/mitogen-activated protein kinase (MAPK) pathway. To further explore the involvement of the Rap1/MAPK pathway in GC development, a pathway activator was added to GC cells with knockdown of F2RL3 expression. This pathway activator not only enhanced the activity, invasion, and migration of GC cells but also promoted the EMT and blood vessel formation. CONCLUSIONS: F2RL3 regulates the angiogenesis and EMT of GC cells through the Rap1/MAPK pathway, thus influencing the onset and progression of GC.

Disulfidptosis-related genes of prognostic signature and immune infiltration features in hepatocellular carcinoma supported by bulk and single-cell RNA sequencing data.

Background: Disulfidptosis is a new type of cellular death triggered in response to disulfide stress and is strongly linked to the progression of malignancies. Hepatocellular carcinoma (HCC) is a very common malignancy. Some reports have suggested a link between disulfidptosis-related genes (DRGs) and cancer; however, further research needs to be conducted. Methods: In this study, HCC data from the Cancer Genome Atlas-Liver Hepatocellular Carcinoma and Gene Expression Omnibus data sets were collected and analyzed. A univariate Cox regression analysis, least absolute shrinkage and selection operator, and multivariate Cox regression analysis were conducted to identify the hub DRGs signature for prognosis. The HCC patients were allocated to high- and low-risk groups based on their disulfidptosis risk scores. The model was validated with a high degree of precision using both internal and external validation data sets. "ESTIMATE" and "CIBERSORT" packages were employed to assess the immunological landscapes and immune cell infiltration. The IMvigor210 cohort was chosen to validate the immunotherapy results. A drug sensitivity analysis was conducted to identify targeted medications. The expression of the hub DRGs in the HCC cells was confirmed using cytological techniques. Results: The bioinformatic analysis revealed that 16 genes showed differential expression. A prognostic model was developed based on four genes: RPN1, SLC2A1, SLC2A4, and SLC7A11. A notable difference in prognosis was observed between the two risk groups. Based on the results of the immune microenvironment, tumor mutation burden, immunotherapy, and drug screening analyses, the DRGs signature can be employed in HCC immunotherapy decision making. Further, the expression levels of the hub DRGs were significantly upregulated in the HCC cells. Conclusions: Our four-DRGs signature could be used to predict HCC prognosis. Further, this study showed that the hub DRGs could serve as biomarkers for immunotherapy prediction and could potentially guide targeted therapies.

Relationship between HuR and tumor drug resistance

Human resistance protein R (HuR), also known as embryonic lethal abnormal visual-like protein (ELAVL1), is an RNA-binding protein widely expressed in vivo that affects the mRNA stability of targeted and is involved in post-transcriptional regulation. Recent studies have shown that HuR is aberrantly expressed in different human cancers and is an essential factor in poor clinical prognosis. The role of HuR in numerous tumors suggests that it could be a new target for tumor therapy and as a marker for efficacy and prognostic assessment. This review focuses on the relationship between HuR and drug resistance in different tumors and briefly describes the structure, function, and inhibitors of HuR. We summarize the mechanisms by which HuR causes tumor resistance and the molecular targets affected (AU)

Hypoxia-induced UBE2K promotes the malignant progression of HCC.

BACKGROUND: Hypoxia critically drives malignant tumor development and is characteristic of hepatocellular carcinoma (HCC), where HIF-1α plays a crucial role. The ubiquitin-conjugating enzyme E2K (UBE2K) is known to participate in the advancement of several human cancers. However, the role of UBE2K in HCC or whether it is a hypoxia-responsive gene remains to be further identified. METHOD: We performed a microarray to measure the gene expression differences between normoxia and hypoxia. CoCl2 mimicked the hypoxic condition. The protein and RNA expression of HIF-1α, UBE2K, and Actin in HCC cells were measured by western blotting(WB) and RT-qPCR, respectively. Immunohistochemical (IHC) staining analyzed the expression of UBE2K and HIF-1α in HCC tissues. CCK-8 and colony formation assay evaluated the HCC cell growth. Scratch healing and transwell assays were used to detect the migration capability of the cells. Lipofectamine 3000 was used to transfect the plasmids or siRNAs to HCC cells. RESULTS: We identified UBE2K as a potential hypoxia-responsive gene. Our study showed that hypoxia induced HIF-1α-mediated increase of UBE2K levels in HCC cells, which decreased under HIF-1α deficiency under hypoxia. Further bioinformatics analysis based on UALCAN and GEPIA databases confirmed that UBE2K was highly expressed in HCC tissues and positively associated with HIF-1α expression. Functionally, Hep3B and Huh7 cell proliferation and migration were stimulated upon UBE2K overexpression, while the UBE2K knockdown suppressed such effect. Furthermore, functional rescue experiment proved that depletion of UBE2K inhibited hypoxia-induced cell proliferation and migration in HCC cells. In contrast, enhancing UBE2K levels rescued cell proliferation and migration repression caused by HIF-1α deficiency in hypoxia. CONCLUSION: Our results established UBE2K as a potential hypoxia-inducible gene in HCC cells, positively regulated by HIF-1α in hypoxia. Moreover, UBE2K served as an oncogene and cooperated with HIF-1α to form a functional HIF-1α/UBE2K axis to trigger HCC progression, highlighting a potential application of UBE2K as a therapeutic target for HCC treatment.

Stable Lanthanide-Organic Frameworks: Crystal Structure, Photoluminescence, and Chemical Sensing of Vanillylmandelic Acid as a Biomarker of Pheochromocytoma.

Several isostructural lanthanide metal-organic frameworks, viz. [Ln(DCHB)1.5phen]n (Ln-MOFs, where Ln = Eu for 1, Tb for 2, Sm for 3 and Dy for 4), are successfully synthesized through the hydrothermal reactions of 4'-di(4-carboxylphenoxy)hydroxyl-2, 2'-bipyridyl (H2DCHB) and lanthanide nitrates as well as chelator 1,10-phenantroline (phen). These structures are characterized by single-crystal X-ray diffraction, and the representative Ln-MOF 1 is a fivefold interpenetrated framework with the uncoordinated Lewis base N sites form DCHB2- ligands. The photoluminescence research studies reveal that Ln-MOFs 1-4 exhibit characteristic fluorescent emissions from ligand-induced lanthanide Ln(III) ions, while the single-component emission spectra of Ln-MOF 4 are all located in a white region under different excitations. The absence of coordinated water and the interpenetration property of the structures are conducive to the structure rigidity, and the results display that Ln-MOF 1 has high thermal/chemical stabilities in common solvents and a wide pH range as well as the boiling water. Notably, luminescent sensing studies reveal that Ln-MOF 1 with prominent fluorescence properties can perform in highly sensitive and selective sensing of vanillylmandelic acid (VMA) in aqueous systems (KSV = 562.8 L·mol-1; LOD = 4.6 × 10-4 M), which can potentially establish a detection platform for the diagnosis of pheochromocytoma via multiquenching mechanisms. Moreover, the 1@MMMs sensing membranes comprised of Ln-MOF 1 and a poly(vinylidene fluoride) (PVDF) polymer can also be facilely developed for VMA detection in aqueous media, suggesting the enhanced convenience and efficiency of practical sensing applications.

Relationship between HuR and tumor drug resistance.

Human resistance protein R (HuR), also known as embryonic lethal abnormal visual-like protein (ELAVL1), is an RNA-binding protein widely expressed in vivo that affects the mRNA stability of targeted and is involved in post-transcriptional regulation. Recent studies have shown that HuR is aberrantly expressed in different human cancers and is an essential factor in poor clinical prognosis. The role of HuR in numerous tumors suggests that it could be a new target for tumor therapy and as a marker for efficacy and prognostic assessment. This review focuses on the relationship between HuR and drug resistance in different tumors and briefly describes the structure, function, and inhibitors of HuR. We summarize the mechanisms by which HuR causes tumor resistance and the molecular targets affected.

UCHL3 promotes hepatocellular carcinoma cell migration by de-ubiquitinating and stabilizing Vimentin.

Background: Hepatocellular carcinoma (HCC) is a common malignant tumor associated with a poor prognosis. Ubiquitin carboxyl-terminal hydrolase L3 (UCHL3) has been reported to promote diverse tumors, but little is known about its role in HCC. Methods: Expression levels of UCHL3 in Huh7 and Hep3B cells were measured by qRT-PCR. UCHL3, Vimentin protein levels, and ubiquitination levels were determined by Western blot assay. co-immunoprecipitation, Immunofluorescence, and IHC were used to detect the interaction and expression association between UCHL3 and Vimentin in the cells. Wound healing and Transwell assays were used to measure cell migration. Spheroid formation assay were used to assess stem-like properties. Results: UCHL3 expression was found to be significantly elevated in HCC and associated with poor prognosis. UCHL3 promoted migration and stem-like properties of HCC cells. Vimentin was identified as a potential de-ubiquitination substrate of UCHL3 and UCHL3 interacted with and promoted the de-ubiquitination of Vimentin, enhancing its stability. Moreover, the suppression of UCHL3 by siRNA or the inhibition by TCID upregulated ubiquitinated Vimentin. Vimentin attenuated the suppression of cell migration caused by knockdown of UCHL3. Conclusion: UCHL3 was highly expressed in HCC and functioned as an oncogene. Vimentin is a novel substrate of UCHL3 and its stabilization and de-ubiquitination enhanced HCC cell migration.

UBE2K regulated by IGF2BP3 promotes cell proliferation and stemness in pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a noteworthy malignant carcinoma with an unsatisfactory prognosis attributed to late diagnosis. Ubiquitin­conjugating enzyme E2K (UBE2K) has been found to serve important roles in a number of diseases. However, its function and the exact molecular mechanism of UBE2K in PDAC remain to be elucidated. The present study discovered that UBE2K was expressed at high levels and indicated the poor prognosis of patients with PDAC. Following this, the CCK­8, colony formation, and sphere formation assays showed that UBE2K promoted proliferation and the stemness phenotype of PDAC cells in vitro. Evidence from subcutaneous tumor­bearing nude mice experiments further confirmed that UBE2K enhanced PDAC cell tumorigenesis in vivo. Additionally, the present study demonstrated that insulin­like growth factor 2 RNA binding protein 3 (IGF2BP3) functioned as an RNA­binding protein to increase UBE2K expression by enhancing the RNA stability of UBE2K. The knockdown or overexpression of IGF2BP3 could attenuate the change in cells growth induced by the overexpression or knockdown of UBE2K. In summary, the findings indicated the oncogenic roles of UBE2K in PDAC. In addition, IGF2BP3 and UBE2K constitute a functional axis to regulate the malignant progression of PDAC.

LncRNA FRMD6-AS1 promotes hepatocellular carcinoma cell migration and stemness by regulating SENP1/HIF-1α axis.

BACKGROUND: Long non-cording RNAs (lncRNAs) drive the malignant progression of hepatocellular carcinoma (HCC), a cancer with high mortality rates but the function of FERM Domain Containing 6 antisense RNA 1 (FRMD6-AS1) in HCC has not been fully addressed. Hypoxia-inducible factors (HIFs) are transcription factors relevant to HCC under hypoxia and are regulated by SUMO-specific protease 1 (SENP1) through its deSUMOylation of HIF-1α. The current study investigated the role of FRMD6-AS1 in the regulation of SENP1-mediated deSUMOylation of HIF-1α. METHODS: HUH7 and MHCC97H cells were treated with CoCl2 to mimic hypoxia in vitro and lentiviral vector-mediated FRMD6-AS1 overexpressing HCC cells were established. Wound-healing, Transwell, sphere formation assay, Western blotting analysis and animal experiments were performed. Expression of FRMD6-AS1, SENP1 mRNA and HIF-1α mRNA was assessed by RT-qPCR and of HIF-1α and SENP1 protein by Western blot. DeSUMOylation of HIF-1α was detected by immunoprecipitation. RNA immunoprecipitation with SENP1 antibody or IgG was performed to assess endogenous interactions between SENP1 and FRMD6-AS1. RESULTS: FRMD6-AS1 was upregulated in HCC tissues and cells and its upregulation indicated poor prognosis for HCC patients. FRMD6-AS1 promoted HCC cells migration and stemness in vitro and also promoted tumor growth in an in vivo mouse xenograft model. Mechanistic studies showed that FRMD6-AS1 regulated the level of HIF-1α protein but not the mRNA and this effect was achieved by binding to SENP1 protein and enhancing its protease activity. Rescue experiments demonstrated the oncogenic role of the FRMD6-AS1/SENP1/ HIF-1α axis in HCC cells. CONCLUSIONS: High FRMD6-AS1 expression was associated with poor prognosis of HCC patients. FRMD6-AS1 may have an oncogenic role in HCC via regulation of the SENP1/HIF-1α axis and may be a prognostic biomarker for HCC. Blockade of FRMD6-AS1 may offer a novel therapeutic approach to restrict HCC progression.

Ubiquitin­conjugating enzymes as potential biomarkers and therapeutic targets for digestive system cancers (Review).

Digestive system cancers are the leading cause of cancer­related death worldwide due to their high morbidity and mortality rates. The current treatment methods include surgical treatment, chemotherapy, radiotherapy and endoscopic treatment, and the precisely targeted therapy of digestive system cancers requires to be further studied. The ubiquitin­proteasome system is the main pathway for protein degradation in cells and the ubiquitin­conjugating enzymes (E2s) have a decisive role in the specific selection of target proteins for degradation. The E2s have an important physiological role in digestive system cancers, which is related to the clinical tumor stage, differentiation degree and poor prognosis. Furthermore, they are involved in the physiological processes of digestive system tumor cell proliferation, migration, invasion, stemness, drug resistance and autophagy. In the present article, the progress and achievements of the E2s in gastric cancer, hepatocellular carcinoma, pancreatic cancer, colorectal cancer, intrahepatic cholangiocarcinoma, gallbladder cancer and esophageal squamous cell carcinoma were reviewed, which may provide early screening indicators and reliable therapeutic targets for digestive system cancers.

UBE2K promotes the malignant progression of hepatocellular carcinoma by regulating c-Myc.

Hepatocellular carcinoma (HCC) is a serious threat to human health and life due to its high morbidity and mortality. Ubiquitin-conjugating enzymes are players in the ubiquitin proteasome system and are responsible for a great number of physiological activities in cells. The action of ubiquitin-conjugating enzyme UBE2K in HCC has not been reported. Therefore, we studied the function and role of UBE2K in the malignant progression of HCC. An analysis of UBE2K expression in HCC cells was performed using RT-qPCR and protein immunoblotting. CCK-8, Transwell and sphere formation assays were used to identify the potential effects of UBE2K in HCC cell proliferation, migration and stemness property. RT-qPCR, and protein immunoblotting experiments was taken to explore the regulation between UBE2K and c-Myc. Here, we discovered that UBE2K expression was elevated in HCC cells, and elevated UBE2K predicts worse prognosis for HCC patients. Functionally, UBE2K promote, while UBE2K knockdown suppressed cell proliferation, migration and stemness property of HCC cells. Furthermore, c-Myc was identified as a downstream target of UBE2K. Moreover, functional rescue experiments finally proved that UBE2K facilitates the malignant progression of HCC cells by upregulating c-Myc. We clarified through in vivo experiments that UBE2K expression promotes tumor growth in HCC. Taken together, our study results proved the molecular regulation of UBE2K and c-Myc in HCC and the oncogenic role of UBE2K/c-Myc axis in HCC progression, thus it provides a promising molecular target for the diagnosis and treatment of HCC.

LncRNA ALKBH3-AS1 enhances ALKBH3 mRNA stability to promote hepatocellular carcinoma cell proliferation and invasion.

Long noncoding RNAs (lncRNAs) are confirmed as the key regulators of hepatocellular carcinoma (HCC) occurrence and progression, but the role of AlkB homologue 3 antisense RNA 1 (ALKBH3-AS1) in HCC is unclear. We revealed the overexpression of ALKBH3-AS1 in HCC tissues. The upregulated levels of ALKBH3-AS1 were observed in HCC cells. ALKBH3-AS1 was expressed in the nucleus and cytoplasm of HCC cells. The high ALKBH3-AS1 expression was markedly associated with a decreased survival rate of HCC patients. ALKBH3-AS1 knockdown repressed and ALKBH3-AS1 overexpression enhanced HCC cell invasion and proliferation. ALKBH3-AS1 silencing restricted HCC growth in vivo. A significant positive correlation between ALKBH3-AS1 and ALKBH3 mRNA levels was confirmed in HCC specimens. ALKBH3-AS1 silencing reduced ALKBH3 expression by stabilizing its mRNA stability in HCC cells. Notably, the impact of ALKBH3 silencing on HCC cells was similar to that of ALKBH3-AS1 knockdown. ALKBH3 restoration prominently attenuated the suppressive effects resulting from ALKBH3-AS1 silencing in HCCLM3 cells. Hypoxia-inducible factor-1α (HIF-1α) transcriptionally activated ALKBH3-AS1 expression in hypoxic HCC cells. ALKBH3-AS1 knockdown markedly attenuated cell proliferation and invasion in hypoxic Huh7 cells. Collectively, HIF-1α-activated ALKBH3-AS1 exerted an oncogenic role by enhancing ALKBH3 mRNA stability in HCC cells.

The Emerging Role of RNA N6-Methyladenosine Modification in Pancreatic Cancer.

Pancreatic cancer (PC) is one of the most common malignant cancers, ranking the seventh highest causes of cancer-related deaths globally. Recently, RNA N6-methyladenosine (m6A) is emerging as one of the most abundant RNA modifications in eukaryote cells, involved in multiple RNA processes including RNA translocation, alternative splicing, maturation, stability, and degradation. As reported, m6A was dynamically and reversibly regulated by its "writers", "erasers", and "readers", Increasing evidence has revealed the vital role of m6A modification in the development of multiple types of cancers including PC. Currently, aberrant m6A modification level has been found in both PC tissues and cell lines. Moreover, abnormal expressions of m6A regulators and m6A-modified genes have been reported to contribute to the malignant development of PC. Here in this review, we will focus on the function and molecular mechanism of m6A-modulated RNAs including coding RNAs as well as non-coding RNAs. Then the m6A regulators will be summarized to reveal their potential applications in the clinical diagnosis, prognosis, and therapeutics of PC.

A case of infectious mononucleosis complicated with spontaneous atraumatic splenic rapture caused by Epstein-Barr virus infection.

Splenic rupture is the most serious complication of infectious mononucleosis (IM) caused by Epstein-Barr virus (EBV) infection, with a mortality rate of over 1 in 10. We reported a case of spontaneous atraumatic splenic rupture secondary to IM in a young man. The patient presented with abdominal pain caused by splenic rupture as the initial symptom. The diagnosis and treatment process went through a series of twists and turns, including the emergency department, general surgery department, and infection department. This case suggests that clinicians should consider the possibility of EBV infection in young patients with spleen rupture without obvious cause to avoid misdiagnosis and missed diagnosis.

Research Progress of DUB Enzyme in Hepatocellular Carcinoma.

According to GLOBOCAN 2021 cancer incidence and mortality statistics compiled by the International Agency for Research on Cancer, hepatocellular carcinoma (HCC) is the most common malignancy in the human liver and one of the leading causes of cancer death worldwide. Although there have been great advances in the treatment of HCC, such as regofenib, sorafenib, and lomvatinib, which have been developed and approved for the clinical treatment of advanced or metastatic HCC. However, they only prolong survival by a few months, and patients with advanced liver cancer are susceptible to tumor invasion metastasis and drug resistance. Ubiquitination modification is a type of post-translational modification of proteins. It can affect the physiological activity of cells by regulating the localization, stability and activity of proteins, such as: gene transcription, DNA damage signaling and other pathways. The reversible process of ubiquitination is called de-ubiquitination: it is the process of re-releasing ubiquitinated substrates with the participation of de-ubiquitinases (DUBs) and other active substances. There is growing evidence that many dysregulations of DUBs are associated with tumorigenesis. Although dysregulation of deuquitinase function is often found in HCC and other cancers, The mechanisms of action of many DUBs in HCC have not been elucidated. In this review, we focused on several deubiquitinases (DUBs) associated with hepatocellular carcinoma, including their structure, function, and relationship to hepatocellular carcinoma. hepatocellular carcinoma was highlighted, as well as the latest research reports. Among them, we focus on the USP family and OTU family which are more studied in the HCC. In addition, we discussed the prospects and significance of targeting DUBs as a new strategy for the treatment of hepatocellular carcinoma. It also briefly summarizes the research progress of some DUB-related small molecule inhibitors and their clinical application significance as a treatment for HCC in the future.

HIF-1/2α-Activated RNF146 Enhances the Proliferation and Glycolysis of Hepatocellular Carcinoma Cells via the PTEN/AKT/mTOR Pathway.

Hypoxia microenvironment, a critical feature of hepatocellular carcinoma, contributes to hepatocarcinogenesis, tumor progression and therapeutic resistance. Hypoxia-inducible factors (HIFs)-activated target genes are the main effectors in hypoxia-induced HCC progression. In this study, we identified ubiquitin E3 ligase ring finger protein 146 (RNF146) as a novel HIFs target gene. Either HIF-1α or HIF-2α knockdown significantly repressed hypoxia-induced RNF146 upregulation in Hep3B and Huh7 cells. TCGA data and our immunohistochemistry analysis consistently revealed the overexpression of RNF146 in HCC tissues. The upregulated expression of RNF146 was also detected in HCC cell lines. The high RNF146 level was correlated with poor clinical features and predicted a shorter overall survival of patients with HCC. RNF146 knockdown suppressed the proliferation, colony formation and glycolysis of HCC cells, but suppressed but RNF146 overexpression promoted these malignant behaviors. Moreover, RNF146 silencing weakened HCC growth in mice. RNF146 inversely regulated phosphatase and tensin homolog (PTEN) protein level, thereby activating the AKT/mechanistic target of rapamycin kinase (mTOR) pathway in HCC cells. MG132 reversed RNF146 overexpression-induced PTEN reduction. RNF146 knockdown decreased the ubiquitination and degradation of PTEN in HCC cells. Therefore, we clarified that PTEN knockdown notably abolished the effects of RNF146 silencing on the AKT/mTOR pathway and Hep3B cells' proliferation, colony formation and glycolysis. To conclude, our data confirmed that RNF146 was transcriptionally regulated by HIF-1/2α and activated the AKT/mTOR pathway by promoting the ubiquitin proteolysis of PTEN, thereby contributing to HCC progression. RNF146 may be a potential new drug target for anti-HCC.

Case Report: Retroperitoneal Sarcoma in Six Operations: Our Experience in Operative Management of Blood Vessels.

Here we introduce a case of retroperitoneal liposarcoma, which is characterized by repeated recurrences after surgery, and has undergone a total of 6 operations. The diameter of the tumor was about 26 cm at the time of the patient's diagnosis. The imaging examination revealed that the surrounding organs and blood vessels were invaded, which brought great challenges to radical resection. The postoperative pathology of the patient's first operation was dedifferentiated liposarcoma, and some areas showed myxofibrosarcoma differentiation. With the recurrence of sarcoma, myxofibrosarcoma dedifferentiated into rhabdomyosarcoma, and malignant fibrous histiocytoma appeared in some areas. How to treat this type of patient after recurrence? How to deal with blood vessels wrapped by sarcoma during surgery? The medical community has not yet reached the same conclusion. We describe the process of treating the patient and the experience of dealing with blood vessels during surgery.

UBE2O promotes hepatocellular carcinoma cell proliferation and invasion by regulating the AMPKα2/mTOR pathway.

The ubiquitin-conjugating enzyme (E2) is a critical component of the ubiquitin-proteasome system and regulates hepatocarcinogenesis by controlling protein degradation. Ubiquitin-conjugating enzyme E2 O (UBE2O), a member of the E2 family, functions as an oncogene in human cancers. Nevertheless, the role of UBE2O in hepatocellular carcinoma (HCC) remains unknown yet. Here, we demonstrated that the UBE2O level was markedly upregulated in HCC compared with adjacent noncancerous tissues. UBE2O overexpression was also confirmed in HCC cell lines. UBE2O overexpression was prominently associated with advanced tumor stage, high tumor grade, venous infiltration, and reduced HCC patients' survivals. UBE2O knockdown inhibited the migration, invasion, and proliferation of HCCLM3 cells. UBE2O overexpression enhanced the proliferation and mobility of Huh7 cells. Mechanistically, UBE2O mediated the ubiquitination and degradation of AMP-activated protein kinase α2 (AMPKα2) in HCC cells. UBE2O silencing prominently increased AMPKα2 level and reduced phosphorylated mechanistic target of rapamycin kinase (p-mTOR), MYC, Cyclin D1, HIF1α, and SREBP1 levels in HCCLM3 cells. UBE2O depletion markedly activated the AMPKα2/mTOR pathway in Huh7 cells. Moreover, AMPKα2 silencing reversed UBE2O downregulation-induced mTOR pathway inactivation. Rapamycin, an inhibitor of mTOR, remarkably abolished UBE2O-induced mTOR phosphorylation and HCC cell proliferation and mobility. To conclude, UBE2O was highly expressed in HCC and its overexpression conferred to the poor clinical outcomes of patients. UBE2O contributed to the malignant behaviors of HCC cells, including cell proliferation, migration, and invasion, by reducing AMPKα2 stability and activating the mTOR pathway.

LncRNA TMEM220-AS1 suppresses hepatocellular carcinoma cell proliferation and invasion by regulating the TMEM220/ß-catenin axis.

Long non-coding RNAs (lncRNAs) are critical drivers and suppressors of human hepatocellular carcinoma (HCC). The downregulation of transmembrane protein 220 antisense RNA 1 (TMEM220-AS1) is correlated with poor prognosis in HCC. Nevertheless, the role of TMEM220-AS1 in HCC and the underlying mechanism remains unclear. In this study, TMEM220-AS1 levels were markedly reduced in HCC tissues compared with noncancerous tissues. TMEM220-AS1 downregulation was confirmed in HCC cell lines. TMEM220-AS1 expression was associated with tumor stage, venous infiltration, tumor size, and survival of HCC patients. TMEM220-AS1 overexpression suppressed the migration, invasion, and proliferation of HCC cells. Interestingly, ectopic expression of TMEM220-AS1 increased TMEM220 levels in HCC cells. Decreased TMEM220 levels were observed in HCC tissues and cell lines. TMEM220 expression was positively correlated with TMEM220-AS1 levels in HCC tissue samples and TMEM220 downregulation was significantly correlated with reduced patient survival. TMEM220 overexpression suppressed HCC cell proliferation and mobility. TMEM220 knockdown eliminated the suppressive effect of TMEM220-AS1 in HCCLM3 cells. Mechanistically, TMEM220 overexpression reduced the nuclear accumulation of ß-catenin and decreased MYC, Cyclin D1, and Snail1 mRNA levels in HCCLM3 cells. BIO, a GSK3ß inhibitor, eliminated TMEM220-induced Wnt/ß-catenin pathway inactivation and inhibited HCC cell proliferation and mobility. In conclusion, TMEM220-AS1 and TMEM220 were expressed at low levels in HCC patients. TMEM220-AS1 inhibited the malignant behavior of HCC cells by enhancing TMEM220 expression and subsequently inactivating the Wnt/ß-catenin pathway.

Erratum: Long noncoding RNA LINC01123 promotes the proliferation and invasion of hepatocellular carcinoma cells by modulating the miR-34a-5p/TUFT1 axis: Erratum.

[This corrects the article DOI: 10.7150/ijbs.45457.].