Ubiquitin-Conjugating Enzyme E2T is an Independent Prognostic Factor and Promotes Gastric Cancer Progression

Unraveling the Role of Ubiquitin-Conjugating Enzyme UBE2T in Tumorigenesis: A Comprehensive Review

Ubiquitin-conjugating enzyme E2 T (UBE2T) is a crucial E2 enzyme in the ubiquitin-proteasome system (UPS), playing a significant role in the ubiquitination of proteins and influencing a wide range of cellular processes, including proliferation, differentiation, apoptosis, invasion, and metabolism. Its overexpression has been implicated in various malignancies, such as lung adenocarcinoma, gastric cancer, pancreatic cancer, liver cancer, and ovarian cancer, where it correlates strongly with disease progression. UBE2T facilitates tumorigenesis and malignant behaviors by mediating essential functions such as DNA repair, apoptosis, cell cycle regulation, and the activation of oncogenic signaling pathways. High levels of UBE2T expression are associated with poor survival outcomes, highlighting its potential as a molecular biomarker for cancer prognosis. Increasing evidence suggests that UBE2T acts as an oncogene and could serve as a promising therapeutic target in cancer treatment. This review aims to provide a detailed overview of UBE2T's structure, functions, and molecular mechanisms involved in cancer progression as well as recent developments in UBE2T-targeted inhibitors. Such insights may pave the way for novel strategies in cancer diagnosis and treatment, enhancing our understanding of UBE2T's role in cancer biology and supporting the development of innovative therapeutic approaches.

Anti-UBE2T antibody: A novel biomarker of progressive-fibrosing interstitial lung disease

BACKGROUND

Anti-fibrotic therapy has demonstrated efficacy against progressive-fibrosing interstitial lung disease (PF-ILD); therefore, identifying disease behavior before progression has become a priority. As autoimmunity is implicated in the pathogenesis of various ILDs, this study explored circulating biomarkers that could predict the chronic progressive behavior of ILDs.

METHODS

A single-center retrospective cohort study was conducted. Circulating autoantibodies in patients with ILD were screened using microarray analysis to identify candidate biomarkers. An enzyme-linked immunosorbent assay was performed with a larger sample set for the quantification of antibodies. After 2 years of follow-up, ILDs were reclassified as PF or non-PF. The relationship between the participants' autoantibody levels measured at enrolment and final diagnosis of PF-ILD was determined.

RESULTS

In total, 61 healthy participants and 66 patients with ILDs were enrolled. Anti-ubiquitin-conjugating enzyme E2T (UBE2T) antibody was detected as a candidate biomarker. Anti-UBE2T antibody levels were elevated in patients with idiopathic pulmonary fibrosis (IPF). After following up on the study participants for 2 years, anti-UBE2T levels measured at enrolment significantly correlated with the new PF-ILD diagnosis. Immunohistochemical staining of normal lung tissues revealed sparsely located UBE2T in the bronchiole epithelium and macrophages, whereas IPF lung tissues showed robust expression in the epithelial lining of honeycomb structures.

CONCLUSION

To our knowledge, this is the first report to describe an anti-UBE2T antibody, a new biomarker that is significantly elevated in patients with ILD who present future disease progression.

UPS: Opportunities and challenges for gastric cancer treatment

Gastric cancer remains the fourth most frequently diagnosed malignancy and the fifth leading cause of cancer-related mortality worldwide owning to the lack of efficient drugs and targets for therapy. Accumulating evidence indicates that UPS, which consists of E1, E2, and E3 enzymes and proteasome, plays an important role in the GC tumorigenesis. The imbalance of UPS impairs the protein homeostasis network during development of GC. Therefore, modulating these enzymes and proteasome may be a promising strategy for GC target therapy. Besides, PROTAC, a strategy using UPS to degrade the target protein, is an emerging tool for drug development. Thus far, more and more PROTAC drugs enter clinical trials for cancer therapy. Here, we will analyze the abnormal expression enzymes in UPS and summarize the E3 enzymes which can be developed in PROTAC so that it can contribute to the development of UPS modulator and PROTAC technology for GC therapy.

UBE2T/STAT3 Signaling Promotes the Proliferation and Tumorigenesis in Retinoblastoma

Purpose

The purpose of this paper was to investigate the expression and function of Ubiquitin-conjugating enzyme 2T (UBE2T), a human E2 ubiquitin-conjugating enzyme, in human retinoblastoma.

Methods

The expression of UBE2T in normal retina and retinoblastoma was analyzed using the Gene Expression Omnibus (GEO) databases, and its expression was immunohistochemically evaluated in 29 retinoblastoma sections and 5 normal retinas. Then CCK-8, flow cytometry, RNA-sequencing analysis, and in vivo assays were performed to explore the exact role of UBE2T in retinoblastoma.

Results

We found that retinoblastoma showed higher UBE2T expression than normal retina in GEO datasets and tissues. The immunoreactive score of UBE2T ≥4 was associated with group E in IIRC, T2-T4b in pTNM staging, poorly differentiated retinoblastoma, and high-risk histopathological factors. Knockdown of UBE2T reduced the cell viability, increased the apoptosis cells and G0/G1 cells, and inhibited subcutaneous tumor growth in vivo. Mechanistic studies showed that UBE2T knockdown induced down-regulation of phosphorylation of STAT3 and its downstream genes in vitro and in vivo. Rescue assays confirmed that STAT3 signaling pathway was involved in the effect of reduced cell viability, elevated apoptosis cells, and G0/G1 cells mediated by UBE2T knockdown.

Conclusions

Our data indicate that UBE2T significantly participates in the proliferation of retinoblastoma via the STAT3 signaling pathway, suggesting the potential of UBE2T as a therapeutic target for retinoblastoma treatment.

E2F5 promotes proliferation and invasion of gastric cancer through directly upregulating UBE2T transcription

The underlying mechanisms of E2F5 upregulation and its pro-tumor functions have not been elucidated in gastric cancer (GC). Here, the expression, prognostic value, mutation status, and promoter methylation of E2F5 were evaluated. The effects of E2F5 depletion on cell proliferation and invasion in GC, were also assessed through in vitro experiments. Additionally, gene set enrichment analysis (GSEA) was applied to analyze the potential downstream regulator of E2F5. The study also assessed the correlation and transcription regulation between E2F5 and UBE2T. Finally, the roles of UBE2T in E2F5-related pro-tumor functions were examined. The findings revealed that E2F5 was upregulated and showed remarkable association with pathological variables and prognosis. Hypomethylation of the E2F5 promoter predicted poor prognosis and partially caused E2F5 upregulation in GC. E2F5 knockdown significantly inhibited the proliferation and invasion of GC cells. E2F5 had a significant positive correlation with UBE2T in GC. Mechanistically, E2F5 promoted UBE2T transcription and UBE2T overexpression reversed the effects of E2F5 depletion on the proliferation and invasion of cells in GC. Taken together, this study originally confirmed the upregulation of E2F5 in GC, revealed that E2F5 can directly upregulate UBE2T transcription, and subsequently promote the malignant progression, which highlights that the E2F5/UBE2T axis can potentially be used in the diagnosis and treatment of GC.

UBE2T is upregulated, predicts poor prognosis, and promotes cell proliferation and invasion by promoting epithelial-mesenchymal transition via inhibiting autophagy in an AKT/mTOR dependent manner in ovarian cancer

Aberrant upregulation and oncogenic roles of UBE2T are revealed in several cancers. However, the expression, clinical significance, and functions of UBE2T have not been explored in ovarian cancer (OC). In this study, the expression of UBE2T and its relation with clinicopathological features and prognosis of OC patients were explored by analyzing online data and experimental data. Besides, the functions of UBE2T in OC cells were investigated by in vitro experiments, including CCK-8, plate clone formation, and Transwell assays. Finally, the underlying mechanism of UBE2T associated functions in OC was analyzed. The results indicated that UBE2T was significantly upregulated in OC tissues. UBE2T expression was notably correlated with clinical features, such as primary T stage and FIGO stage in OC patients. UBE2T, acting as an independent prognostic indicator, was inversely associated with the prognosis of OC patients. The UBE2T knockdown remarkably suppressed the growth, proliferation, and invasion of OC cells, indicated by impaired cell viability, fewer cell clones, and invasive cells. Mechanistically, UBE2T depletion suppressed epithelial-mesenchymal transition (EMT), which was caused by autophagy activation due to inactivation of AKT/mTOR in OC cells with UBE2T knockdown. Collectively, our findings confirm that UBE2T upregulation predicts poor prognosis and promotes malignant progression in OC. UBE2T upregulation suppresses autophagy and subsequently boosts EMT via activating the AKT/mTOR axis, which accounts for the underlying mechanism of oncogenic roles of UBE2T in OC.

miR-498 Targets UBE2T to Inhibit the Proliferation of Malignant Melanoma Cells

Background: Malignant melanoma is a common malignant tumor and one of the tumors with the fastest growing incidence. The effect of microRNAs on the biological processing of malignant melanoma cells also have been reported. This study explores the ability of miR-498 to regulate the progression of malignant melanoma cells. Methods: The expression of miR-498 was detected by RT-qPCR. The proliferation, invasion, and migration of malignant melanoma cells were measured by cell counting kit-8, clone formation, and transwell assays. Flow cytometry assay detected the percentage of apoptotic cells. Western blot was used to detect the expression of markers related to epithelial-mesenchymal transition. The correction of miR-498 and UBE2T was explored by dual-luciferase assay and Western blot. Results: Overexpression of miR-498 inhibited the proliferation, invasion, migration, and induced cell apoptosis of M14 and A375 cells. In addition, the expression of epithelial-mesenchymal transition-related factors was altered by the overexpression of miR-498. miR-498 can directly target UBE2T 3'-UTR and inhibit UBE2T protein expression. The overexpression of UBE2T reversed the inhibitory effects of miR-498 on the progression of malignant melanoma cells. Furthermore, UBE2T mRNA was significantly highly expressed in malignant melanoma tissues. The high expression of UBE2T was associated with the poor overall survival rate of malignant melanoma patients. Conclusions: Altogether, our findings demonstrated that miR-498 significantly inhibited the proliferation, invasion, migration, and induced apoptosis of malignant melanoma cells and confirmed that miR-498 regulated malignant melanoma cell progression by targeting UBE2T.

The expression of circ_0090049 in hepatocellular carcinoma and the molecular regulation mechanism of other biological functions

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in liver cancer. Circular RNA_0090049 (circ_0090049) has been shown to be involved in the advance of HCC. However, the interaction between circ_0090049 and microRNA (miRNA) in HCC has not been studied. Quantitative real-time PCR was used to detect the expression of related genes. Through detection of cell proliferation, migration, invasion, and rate of tumor sphere formation, the capping experiment was carried out to verify the regulatory relationship between miRNA and circ_0090049 or circ_0090049 and ubiquitin-conjugating enzyme E2 T (UBE2T). The expression of related proteins was detected by Western blotting. The interaction of miRNA with circ_0090049 or UBE2T was notarized by Dual-luciferase reporter assay. Xenotransplantation experiments confirmed the function of circ_0090049 in vivo. Circ_0090049 and UBE2T were upregulated in liver cancer. Silencing circ_0090049 reduced the proliferation, migration, invasion, and tumor spheroid formation rate of Huh7 and HCCLM3 cells. MiR-605-5p and miR-548c-3p were identified as targets of circ_0090049, and UBE2T was the target of miR-605-5p and miR-548c-3p. Anti-miR-605-5p, anti-miR-548c-3p or UBE2T overexpression restored the inhibitory effect of circ_0090049 knockdown on HCC cells. Animal experiments confirmed the antitumor effect of silence circ_0090049. Circ_0090049 regulates the expression of UBE2T by regulating miR-605-5p or miR-548c-3p, thereby promoting the development of HCC cells.

LncRNA CASC11 Promotes Hepatocellular Carcinoma Progression via Upregulation of UBE2T in a m6A-Dependent Manner

Hepatocellular carcinoma (HCC) is one of the most frequent malignancies and the third leading cause of cancer-related deaths worldwide. Besides, it has been revealed that long non-coding RNA (LncRNA) cancer susceptibility candidate 11 (CASC11) is involved in cancer progression. However, the functional role and underlying mechanism of CASC11 in HCC remains largely unknown. In this context, here, it was found that CASC11 was upregulated in HCC tissues and associated with tumor grades, metastasis, and prognosis of HCC patients. Functionally, CASC11 facilitated HCC cell proliferation, migration, and invasion in vitro, and enhanced tumor growth and metastasis in vivo. Mechanistically, CASC11 associated with and stabilized Ubiquitin-conjugating enzyme E2T (UBE2T) mRNA. To be specific, it decreased UBE2T N⁶-methyladenosine (m⁶A) level via recruiting ALKBH5. Moreover, CASC11 inhibited the association between UBE2T mRNA and m⁶A reader protein YTHDF2. Taken together, our findings demonstrate the epigenetic mechanism of CASC11 in the regulation of UBE2T expression and possibly provide a novel therapeutic target for HCC treatment.

Ubiquitin-conjugating enzyme E2T promotes tumor stem cell characteristics and migration of cervical cancer cells by regulating the GRP78/FAK pathway

Ubiquitin-conjugating enzyme E2T (UBE2T) functions as an E2 ubiquitin-conjugating enzyme in the ubiquitin-proteasome degradation system and mediates cellular processes, such as cell cycle, proliferation, and differentiation. UBE2T has been considered to be an oncogene in a variety of tumors. However, the oncogenic role of UBE2T in cervical cancer remains unclear. In this study, our results first showed that the expression of UBE2T was higher in both of cervical cancer tissues and cells than that in the normal tissues and cells. Knockdown of UBE2T reduced cervical cancer cell viability and suppressed the proliferation, invasion, and migration. However, overexpression of UBE2T contributed to cervical cancer cell growth and metastasis. Moreover, UBE2T overexpression cervical cancer cells demonstrated enhanced self-renewal capacity with upregulation of SOX2, Oct-4, and Nanog protein. Silencing of UBE2T downregulated protein expression of SOX2, Oct-4, and Nanog in cervical cancer cells reduced self-renewal capacity. Furthermore, ectopic UBE2T expression promoted protein expression of glucose-regulated protein 78 (GRP78) and focal adhesion kinase (FAK) phosphorylation in cervical cancer cells. The knockdown of UBE2T reduced protein expression of GRP78 and FAK phosphorylation. Collectively, UBE2T promoted cervical cancer stem cell traits and exerted an oncogenic role through activation of the GRP78/FAK pathway.

The Molecular Basis of Ubiquitin-Conjugating Enzymes (E2s) as a Potential Target for Cancer Therapy

Ubiquitin-conjugating enzymes (E2s) are one of the three enzymes required by the ubiquitin-proteasome pathway to connect activated ubiquitin to target proteins via ubiquitin ligases. E2s determine the connection type of the ubiquitin chains, and different types of ubiquitin chains regulate the stability and activity of substrate proteins. Thus, E2s participate in the regulation of a variety of biological processes. In recent years, the importance of E2s in human health and diseases has been particularly emphasized. Studies have shown that E2s are dysregulated in variety of cancers, thus it might be a potential therapeutic target. However, the molecular basis of E2s as a therapeutic target has not been described systematically. We reviewed this issue from the perspective of the special position and role of E2s in the ubiquitin-proteasome pathway, the structure of E2s and biological processes they are involved in. In addition, the inhibitors and microRNAs targeting E2s are also summarized. This article not only provides a direction for the development of effective drugs but also lays a foundation for further study on this enzyme in the future.

Ubiquitin-conjugating enzyme E2T(UBE2T) promotes colorectal cancer progression by facilitating ubiquitination and degradation of p53

OBJECTIVES

The expression level of Ubiquitin-conjugating enzyme E2T (UBE2T) is upregulated in various types of human tumors. We explored the correlation and regulatory mechanism of UBE2T in the development of colorectal cancer (CRC).

METHODS

Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to examine the expression of UBE2T in the CRC tissues and cell lines. Immunohistochemical staining, spearman correlation analysis, and Kaplan Meier-survival analysis were used to demonstrate the correlation between UBE2T high expression level and the clinical characteristics of malignant patients and the overall survival. The proliferation, apoptosis, migration and invasion of CRC cells were analyzed by cell transfection, MTT, colony formation, scratch assay, transwell, and flow cytometry. Furthermore, the expression of cell proliferation and apoptosis related proteins and ubiquitination of p53 were detected by western blot.

RESULTS

UBE2T was up-regulated in CRC tissues and cell lines, and high expression level of UBE2T was correlated with the clinical characteristics of malignant of CRC patients (P<0.05), and patients with high expression level of UBE2T had lower overall survival (P=0.0455). In addition, UBE2T could promote the growth, proliferation, invasion and metastasis of CRC cells and inhibit the apoptosis. At the same time, knockdown of UBE2T inhibited the growth of transplanted tumor in mice of subcutaneous CRC model. Moreover, our experimental results proved that UBE2T regulated the expression of downstream related proteins through ubiquitination of p53 protein to promote the occurrence and development of CRC.

CONCLUSION

Our study elucidated that high expression of UBE2T would enhance the development of CRC, and then further explored its molecular mechanism both in vitro and in vivo. The results indicated that UBE2T facilitated ubiquitination and degradation of p53, which predicts the possibility of UBE2T as one of molecular diagnosis markers, prognostic indicators and therapeutic drug targets of CRC patients.

The interplay of UBE2T and Mule in regulating Wnt/β-catenin activation to promote hepatocellular carcinoma progression

Emerging evidence indicates the role of cancer stem cells (CSCs) in tumor relapse and therapeutic resistance in patients with hepatocellular carcinoma (HCC). To identify novel targets against liver CSCs, an integrative analysis of publicly available datasets involving HCC clinical and stemness-related data was employed to select genes that play crucial roles in HCC via regulation of liver CSCs. We revealed an enrichment of an interstrand cross-link repair pathway, in which ubiquitin-conjugating enzyme E2 T (UBE2T) was the most significantly upregulated. Consistently, our data showed that UBE2T was upregulated in enriched liver CSC populations. Clinically, UBE2T overexpression in HCC was further confirmed at mRNA and protein levels and was correlated with advanced tumor stage and poor patient survival. UBE2T was found to be critically involved in the regulation of liver CSCs, as evidenced by increases in self-renewal, drug resistance, tumorigenicity, and metastasis abilities. Mule, an E3 ubiquitin ligase, was identified to be the direct protein binding partner of UBE2T. Rather than the canonical role of acting as a mediator to transfer ubiquitin to E3 ligases, UBE2T is surprisingly able to physically bind and regulate the protein expression of Mule via ubiquitination. Mule was found to directly degrade β-catenin protein, and UBE2T was found to mediate liver CSC functions through direct regulation of Mule-mediated β-catenin degradation; this effect was abolished when the E2 activity of UBE2T was impaired. In conclusion, we revealed a novel UBE2T/Mule/β-catenin signaling cascade that is involved in the regulation of liver CSCs, which provides an attractive potential therapeutic target for HCC.

Downregulated genes by silencing MYC pathway identified with RNA-SEQ analysis as potential prognostic biomarkers in gastric adenocarcinoma

MYC overexpression is a common phenomenon in gastric carcinogenesis. In this study, we identified genes differentially expressed with a downregulated profile in gastric cancer (GC) cell lines with silenced MYC. The TTLL12, CDKN3, CDC16, PTPRA, MZT2B, UBE2T genes were validated using qRT-PCR, western blot and immunohistochemistry in tissues of 213 patients with diffuse and intestinal GC. We identified high levels of TTLL12, MZT2B, CDC16, UBE2T, associated with early and advanced stages, lymph nodes, distant metastases and risk factors such as H. pylori. Our results show that in the diffuse GC the overexpression of CDC16 and UBE2T indicate markers of poor prognosis higher than TTLL12. That is, patients with overexpression of these two genes live less than patients with overexpression of TTLL12. In the intestinal GC, patients who overexpressed CDC16 had a significantly lower survival rate than patients who overexpressed MZT2B and UBE2T, indicating in our data a worse prognostic value of CDC16 compared to the other two genes. PTPRA and CDKN3 proved to be important for assessing tumor progression in the early and advanced stages. In summary, in this study, we identified diagnostic and prognostic biomarkers of GC under the control of MYC, related to the cell cycle and the neoplastic process.

Expression of ubiquitin-conjugating enzyme E2T in colorectal cancers and clinical implications

Ubiquitin-conjugating enzyme E2T (UBE2T) plays a significant role in carcinogenesis. Previous studies have demonstrated that UBE2T promotes the development and progression of numerous types of cancer. However, the association between UBE2T expression and colorectal cancer (CRC) remains unclear. In the present study, UBE2T protein expression was examined in the tissues of patients with CRC via immunohistochemistry. In addition, UBE2T expression data and corresponding clinical information were obtained from The Cancer Genome Atlas (TCGA). In the clinical samples, the associations between UBE2T expression and clinicopathological factors were evaluated by the χ² or Fisher's exact tests. In TCGA data, associations between UBE2T expression and clinical characteristics were evaluated using a logistic regression model. Overall survival was analyzed using Kaplan-Meier and Cox regression analyses. Reverse transcription-quantitative PCR (RT-qPCR) and western blotting assays were used to examine UBE2T expression in normal and CRC cell lines. Gene set enrichment analysis (GSEA) was performed on the dataset from TCGA. UBE2T protein was highly expressed in the cytoplasm of tumor cells in 29/50 clinical samples, whereas in the adjacent normal tissues, it was only highly expressed in 2/50 samples. Furthermore, UBE2T expression was associated with the N classification (P<0.001), clinical TNM stage (P<0.001) and histological grade of tumors (P=0.010). Survival analysis showed an association between high UBE2T expression and poor survival rate in patients with CRC (P=0.002). Cox regression analysis also revealed that UBE2T expression was an independent prognostic factor for these patients (P=0.006). RT-qPCR and western blotting showed that UBE2T was expressed in CRC cell lines at higher levels than that in a normal colon cell line. Analysis of TCGA data revealed that UBE2T was highly expressed in tumor samples compared with normal samples, but was not associated with prognosis. GSEA showed that high expression of UBE2T was associated with the Kyoto Encyclopedia of Genes and Genomes pathways ‘cell cycle’, ‘oxidative phosphorylation’, ‘DNA replication’, ‘p53 signaling pathway’, ‘ubiquitin mediated proteolysis’ and ‘pentose phosphate pathway’. These results indicate that UBE2T may play an important role in the progression of CRC and serve as a potential prognostic factor during the treatment of cancer.

Overexpression of UBE2M through Wnt/β-Catenin signaling is associated with poor prognosis and chemotherapy resistance in colorectal cancer

Background

The expression of ubiquitin-conjugating enzyme E2 M (UBE2M) is elevated in colorectal carcinoma (CRC). However, the underlying mechanisms and effects of UBE2M on the prognosis and drug resistance in CRC have not been investigated.

Methods

CRC specimens and adjacent normal tissues were collected from 74 patients. The expression of UBE2M was measured by quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry. Multivariable cox regression analysis was used to analyze the risk factors for overall survival in clinical CRC patients. Human colorectal cancer cell lines HCT116 and SW480 were transfected with specific UBE2M small interfering ribonucleic acid (siRNA) or plasmid to either suppress or increase the expression of UBE2M for in vitro experiments. Also, chemotherapy-resistant HCT116 and SW480 cells were established by being treated with increasingly higher concentrations of fluorouracil (5-FU) or oxaliplatin. XAV-939 was used as a wingless/integrated-beta-catenin (Wnt/β-catenin) signaling inhibitor.

Results

According to quantitative real-time PCR and immunohistochemistry, the expression of UBE2M was elevated in CRC tissues compared to normal tissues. Based on cox regression analysis, the overexpression of UBE2M was a risk factor for overall survival of CRC patients. The expression of UBE2M was notably high in 5-FU- and oxaliplatin-resistant cells in in vitro experiments. Also, cells transfected with specific UBE2M siRNA or plasmid induced lower resistance to 5-FU and higher resistance to oxaliplatin. Finally, the expression of β-catenin was correlated with the expression of UBE2M in transfected cells and treatment with XAV939 decreased the degree of drug resistance in chemotherapy-resistant HCT116 cells.

Conclusions

Overexpression of UBE2M in CRC specimens contributes to a decreased overall survival of patients and mediates 5-FU and oxaliplatin resistance in CRC cells via the Wnt/β-catenin signaling pathway.

[MicroRNA-145-5p over-expression suppresses proliferation, migration and invasion and promotes apoptosis of human endometrial cancer cells by targeting dual specific phosphatase 6]

OBJECTIVE

To investigate the role of microRNA-145-5p (miR-145-5p) in regulating the proliferation, migration, invasion and apoptosis of human endometrial carcinoma cells.

METHODS

Human endometrial carcinoma Ishikawa cells were transfected with miR-145-5p mimic, miR-145-5p inhibitor, or their negative controls via liposome (Lipo2000), and the changes in the expression of miR-145-5p was verified by real-time PCR. The effects of overexpression or inhibition of miR-145-5p on the proliferation, migration, invasion and apoptosis of the cells were evaluated using MTT assay, wound healing assay, Transwell assay or flow cytometry. Bioinformatic analysis was performed to predict the target genes of miR-145-5p. The mRNA and protein expression levels of the downstream target of miR-145-5p, namely dual specific phosphatase 6 (DUSP6), were detected using real-time PCR and Western blotting.

RESULTS

Transfection of the cells with miR-145-5p mimic significantly suppressed the proliferation of Ishikawa cells, while transfection with miR-145-5p inhibitor obvious enhanced the proliferation of the cells (P < 0.05). Over-expression of miR-145-5p significantly suppressed the migration and invasion and promoted apoptosis of the cells, and inhibition of miR-145-5p caused the reverse changes (P < 0.05). Bioinformatic analysis showed that DUSP6 was the potential target gene of miR-145-5p. Over-expression of miR-145-5p significantly lowered while inhibition of miR-145-5p significantly enhanced the expression of DUSP6 protein (P < 0.05).

CONCLUSIONS

Overexpression of miR-145-5p inhibits the proliferation, migration and invasion and promotes apoptosis of endometrial cancer cells possibly by negative regulation of DUSP6 expression.

Role of ubiquitin-conjugating enzyme E2T in the carcinogenesis and progression of pancreatic cancer

Ubiquitin-conjugating enzyme E2T (UBE2T) is a recently discovered oncogenic protein. Numerous studies reported that UBE2T is highly expressed in various types of human cancer; however, its role in the carcinogenesis and progression of pancreatic cancer remains unknown. The aim of the present study was to investigate the role of UBE2T in pancreatic cancer progression through in vitro experiments in pancreatic cancer tissues and cell lines. The results obtained in the present study demonstrated that UBE2T served an important role in the initiation and progression of pancreatic cancer. Furthermore, increased expression of UBE2T in human pancreatic cancer tissues and pancreatic cancer cells was observed compared with normal tissues and cells. The effect of upregulating and downregulating UBE2T in pancreatic cancer cell lines was investigated using the MTT, wound-healing and migration and invasion assays. The results demonstrated that overexpression of UBE2T significantly promoted pancreatic cancer cell proliferation, migration and invasion compared with controls. However, UBE2T downregulation resulted in the inhibition of pancreatic cancer cell proliferation, migration and invasion. In addition, the results demonstrated that UBE2T may promote the epithelial mesenchymal transition in pancreatic cancer cells.

Screening of potential biomarkers and their predictive value in early stage non-small cell lung cancer: a bioinformatics analysis

BACKGROUND

Non-small cell lung cancer (NSCLC) remains the first leading cause of death in malignancies worldwide. Despite the early screening of NSCLC by low-dose spiral computed tomography (CT) in high-risk individuals caused a 20% reduction in the mortality, there still exists imperative needs for the identification of novel biomarkers for the diagnosis and treatment of lung cancer.

METHODS

mRNA microarray datasets GSE19188, GSE33532, and GSE44077 were searched, and the differentially expressed genes (DEGs) were obtained using GEO2R. Functional and pathway enrichment analyses were performed for the DEGs using DAVID database. Protein-protein interaction (PPI) network was plotted with STRING and visualized by Cytoscape. Module analysis of the PPI network was done through MCODE. The overall survival (OS) analysis of genes from MCODE was performed with the Kaplan Meier-plotter.

RESULTS

A total of 221 DEGs were obtained, which were mainly enriched in the terms related to cell division, cell proliferation, and signal transduction. A PPI network was constructed, consisting of 221 nodes and 739 edges. A significant module including 27 genes was identified in the PPI network. Elevated expression of these genes was associated with poor OS of NSCLC patients, including UBE2T, UNF2, CDKN3, ANLN, CCNB2, and CKAP2L. The enriched functions and pathways included protein binding, ATP binding, cell cycle, and p53 signaling pathway.

CONCLUSIONS

The DEGs in NSCLC have the potential to become useful targets for the diagnosis and treatment of NSCLC.

UBE2T promotes proliferation via G2/M checkpoint in hepatocellular carcinoma

Background

Growing evidence suggests that the ubiquitin-proteasome system is involved in the pathogenesis and recurrence of hepatocellular carcinoma (HCC); yet, little is known about the role of ubiquitin-conjugating enzyme E2T (UBE2T) in HCC.

Materials and methods

UBE2T levels were detected in HCC tissues and hepatoma cell lines using quantitative reserve transcriptase-polymerase chain reaction and Western blot analysis. Next, the changes of phenotypes after UBE2T knockdown or overexpression were evaluated using in vitro methods. Finally, the mechanism of UBE2T in HCC was tested using ex vivo and in vivo methods.

Results

In the present study, we reported that UBE2T mRNA and protein levels were significantly upregulated in HCC tissues compared to adjacent non-tumor tissues. Additionally, suppression of UBE2T expression inhibited proliferation, colony formation, tumorigenesis, migration, and invasion of hepatoma cells, whereas UBE2T overexpression led to the opposite outcomes. Moreover, suppression of UBE2T expression resulted in an increase in G2/M phase and a decrease in the percentage of cells in G1 phase, which indicated a cell cycle arrest at the G2/M phase. In contrast, the percentage of cells in G2/M phase decreased following UBE2T overexpression. Further study indicated that UBE2T regulated the G2/M transition by modulating cyclin B1 and cyclin-dependent kinase 1.

Conclusion

Taken together, the findings of the present study uncover biological functions of UBE2T in hepatoma cells, and delineate preliminary molecular mechanisms of UBE2T in modulating HCC development and progression.

MicroRNA-1305 Inhibits the Stemness of LCSCs and Tumorigenesis by Repressing the UBE2T-Dependent Akt-Signaling Pathway

MicroRNAs (miRNAs) are involved in the maintenance of the cancer stem cell (CSC) phenotype by binding to genes and proteins that modulate cell proliferation and/or cell apoptosis. In our study, we aimed to investigate the role of miR-1305 in the proliferation and self-renewal of liver CSCs (LCSCs) via the ubiquitin-conjugating enzyme E2T (UBE2T)-mediated Akt-signaling pathway. Differentially expressed genes in human hepatocellular carcinoma (HCC) were obtained by in silico analysis. The relationship between miR-1305 and UBE2T was verified by dual luciferase reporter gene assay. qRT-PCR and western blot analysis were performed to determine the expression of UBE2T, the Akt-signaling pathway, and stemness-related factors in LCSCs. In addition, miR-1305 disrupted the activation of the Akt-signaling pathway by targeting UBE2T, and, ultimately, it repressed the sphere formation, colony formation, and proliferation, as well as tumorigenicity of LCSCs. In summary, miR-1305 targeted UBE2T to inhibit the Akt-signaling pathway, thereby suppressing the self-renewal and tumorigenicity of LCSCs. Those findings may provide an enhanced understanding of miR-1305 as a therapeutic target to limit the progression of LCSCs.

UBE2T promotes proliferation and regulates PI3K/Akt signaling in renal cell carcinoma

Renal cell carcinoma (RCC) is a common malignant tumor globally. The overall survival of patients with RCC is poor; one important factor is tumor heterogeneity. Ubiquitin-conjugating enzyme E2T (UBE2T) has been reported to act as an oncogene in various types of cancer; however, its role in RCC has yet to be investigated. In the present study, UBE2T was demonstrated via reverse transcription-quantitative PCR analysis to be significantly upregulated in RCC samples and cell lines compared with in normal tissue and cells. Additionally, UBE2T expression was significantly associated with late tumor stage and high grade in patients with RCC, and patients with high UBE2T expression exhibited poor prognosis compared with patients with low expression. Following knockdown of UBE2T in 786-O cells using RNA interference technology, the proliferation and colony formation of cells were inhibited as determined by an MTT assay and crystal violet staining, respectively; however, the migration and invasion of 786-O cells were not affected, as determined by wound-healing assay and Transwell assays, respectively. Xenograft RCC tumor growth in vivo was also significantly suppressed. The expression levels of two mesenchymal cell markers, N-cadherin and vimentin, were reduced following UBE2T knockdown, whereas E-cadherin and fibronectin levels were increased as determined by western blotting, indicating that epithelial-mesenchymal transition was suppressed. In addition, the phosphorylation levels of PI3K, Akt and mTOR were notably decreased following UBE2T knockdown, but were increased when UBE2T was overexpressed. Wortmannin, an Akt inhibitor, reversed the UBE2T overexpression-induced increase in the phosphorylation of PI3K, Akt and mTOR. Similarly, the UBE2T overexpression-induced promotion of 786-O cell proliferation was also attenuated by wortmannin. In conclusion, UBE2T promoted the proliferation of RCC cells by regulating PI3K/Akt signaling, suggesting it may be a novel target for the treatment of patients with RCC.

New Insights into the Role of E2s in the Pathogenesis of Diseases: Lessons Learned from UBE2O

Intracellular communication via ubiquitin (Ub) signaling impacts all aspects of cell biology and regulates pathways critical to human development and viability; therefore aberrations or defects in Ub signaling can contribute to the pathogenesis of human diseases. Ubiquitination consists of the addition of Ub to a substrate protein via coordinated action of E1-activating, E2-conjugating and E3-ligating enzymes. Approximately 40 E2s have been identified in humans, and most are thought to be involved in Ub transfer; although little information is available regarding the majority of them, emerging evidence has highlighted their importance to human health and disease. In this review, we focus on recent insights into the pathogenetic roles of E2s (particularly the ubiquitin-conjugating enzyme E2O [UBE2O]) in debilitating diseases and cancer, and discuss the tantalizing prospect that E2s may someday serve as potential therapeutic targets for human diseases.

UBE2T promotes hepatocellular carcinoma cell growth via ubiquitination of p53

Deregulation of Ubiquitin-conjugating enzyme E2T (UBE2T) contributes to the progression of human cancers. However, its clinical significance and role in hepatocellular carcinoma (HCC) remain unclear. Here, we show that UBE2T is up-regulated in HCC and exerts oncogenic activities via ubiquitination of p53. High UBE2T expression was correlated with higher pathological grade, advanced TNM stage, tumor vascular invasion, and poor overall and disease-free survivals in two independent cohorts containing 827 patients with HCC. UBE2T was further identified as an independent factor for overall survival by multivariate analyses. Luciferase reporter assays confirmed that UBE2T was directly targeted by miR-543 which was down-regulated in HCC. In vitro experiments demonstrated that UBE2T overexpression promoted, whereas UBE2T knockdown inhibited HCC cell growth. Ectopic expression of UBE2T resulted in the decreases of p53, p21 and Noxa. Further studies revealed that UBE2T facilitated the degradation of p53 protein via enhancing its ubiquitination. Collectively, our findings suggest UBE2T serves as a promising prognostic factor for HCC and functions as an oncogene. The newly identified miR-543/UBE2T/p53 axis may represent a new potential therapeutic target for HCC intervention.

Mechanism and disease association of E2-conjugating enzymes: lessons from UBE2T and UBE2L3

Ubiquitin signalling is a fundamental eukaryotic regulatory system, controlling diverse cellular functions. A cascade of E1, E2, and E3 enzymes is required for assembly of distinct signals, whereas an array of deubiquitinases and ubiquitin-binding modules edit, remove, and translate the signals. In the centre of this cascade sits the E2-conjugating enzyme, relaying activated ubiquitin from the E1 activating enzyme to the substrate, usually via an E3 ubiquitin ligase. Many disease states are associated with dysfunction of ubiquitin signalling, with the E3s being a particular focus. However, recent evidence demonstrates that mutations or impairment of the E2s can lead to severe disease states, including chromosome instability syndromes, cancer predisposition, and immunological disorders. Given their relevance to diseases, E2s may represent an important class of therapeutic targets. In the present study, we review the current understanding of the mechanism of this important family of enzymes, and the role of selected E2s in disease.

Allosteric Targeting of the Fanconi Anemia Ubiquitin-Conjugating Enzyme Ube2T by Fragment Screening

Ube2T is the E2 ubiquitin-conjugating enzyme of the Fanconi anemia DNA repair pathway and it is overexpressed in several cancers, representing an attractive target for the development of inhibitors. Despite the extensive efforts in targeting the ubiquitin system, very few E2 binders have currently been discovered. Herein we report the identification of a new allosteric pocket on Ube2T through a fragment screening using biophysical methods. Several fragments binding to this site inhibit ubiquitin conjugation in vitro.

Knockdown of UBE2T Inhibits Osteosarcoma Cell Proliferation, Migration, and Invasion by Suppressing the PI3K/Akt Signaling Pathway

Ubiquitin-conjugating enzyme E2T (UBE2T), a member of the E2 family, was found to be overexpressed in a great many cancers such as bladder cancer, lung cancer, and prostate cancer. However, there have been no reports on the role of UBE2T in osteosarcoma. In this study, we tried to make the effects of UBE2T on osteosarcoma clear. The study results showed that UBE2T was overexpressed in osteosarcoma tissues and cell lines. Moreover, UBE2T knockdown inhibited osteosarcoma cell proliferation, migration, and invasion. We also observed that UBE2T downregulation could suppress the activity of the PI3K/Akt signaling pathway. Therefore, we concluded that UBE2T exerted its inhibitory effects on osteosarcoma cells via suppressing the PI3K/Akt signaling pathway. These findings indicated that UBE2T may be a potential therapeutic target for osteosarcoma treatment.