GTSE1: a novel TEAD4-E2F1 target gene involved in cell protrusions formation in triple-negative breast cancer cell models

Pan cancer characterization of genes whose expression has been associated with LINE-1 antisense promoter activity

BACKGROUND

Long interspersed nuclear element-1 (LINE-1 or L1) comprises 17% of the human genome. As the only autonomous and active retrotransposons, L1 may take part in cancer initiation and progression in some ways. The studies of L1 in cancer mainly focus on the impact of L1 insertion into the new genome locus. The L1 5´ untranslated region (UTR) also contains antisense promoter (ASP) activity, generating L1-gene chimeric transcripts to a neighbor exon. Some of these ASP-associated genes have been reported to be overexpressed in cancer and promote cancer cell growth. However, little is known about overall expression patterns and the roles of L1 ASP-associated genes in human cancers.

RESULTS

L1 ASP-associated genes were frequently dysregulated in cancer and associated with the cell cycle, the PI3K/AKT pathway, and the GTPase signaling pathway. The expression of L1 ASP-associated genes was correlated with tumor patient prognosis. Hub L1 ASP-associated genes CENPU and MCM2 showed a correlation with immune infiltration, clinical T stage, and cancer stemness in pan-cancer. Knockdown of L1 ASP-associated gene LINC00491 resulted in a significant decrease in tumor growth and migration ability.

CONCLUSIONS

The expression of L1 ASP-associated genes is significantly dysregulated at the pan-cancer level, which is closely related to the tumor microenvironment, progression, and patient prognosis. Hub genes CENPU and MCM2 are expected to be new tumor diagnostic markers and therapeutic targets.

Gene Silencing of Transcription Factor TEAD4 Inhibits Esophageal Cancer Cells by Regulating TCF7

Background: The procancer effect of TEA domain transcription factor 4 (TEAD4) has been gradually discovered. However, its expression in esophageal cancer (EC) cells and its effect on proliferation and apoptosis have not been reported. In this study, we investigated the possible role of TEAD4 in EC cells. Materials and Methods: TEAD4 messenger RNA and protein expression were assessed in EC cell lines by real-time quantitative-PCR and Western blot. Gene silencing approach was employed to investigate the potential role of TEAD4 in cellular growth, proliferation, migration, and invasion in EC cells. The interaction between TEAD4 and transcription factor 7 (TCF7) was verified by co-immunoprecipitation reaction. The cell apoptosis rates of KYSE-30 cells were detected by flow cytometry. Meanwhile, the expression of apoptosis-related proteins in KYSE-30 cells was detected by Western blot analysis. Results: TEAD4 was significantly increased in EC cell lines, interference of TEAD4 inhibited EC cell viability, invasion, and migration, and promotes apoptosis. TCF7 was found when using STRING website to interact with TEAD4 proteins and TCF7 was significantly increased in EC and knockdown expression of TEAD4 hindered biological function of KYSE-30 cells and this effect was reversed by overexpression of TCF7. Conclusions: The findings concluded that TEAD4 is highly expressed in EC cells and gene silencing of TEAD4 inhibits proliferation and promotes apoptosis of EC cells by regulating TCF7. These findings suggested that TEAD4 might be a novel therapeutic target for the prevention of EC.

Transcription profiling of feline mammary carcinomas and derived cell lines reveals biomarkers and drug targets associated with metabolic and cell cycle pathways

The molecular heterogeneity of feline mammary carcinomas (FMCs) represents a prognostic and therapeutic challenge. RNA-Seq-based comparative transcriptomic profiling serves to identify recurrent and exclusive differentially expressed genes (DEGs) across sample types and molecular subtypes. Using mass-parallel RNA-Seq, we identified DEGs and performed comparative function-based analysis across 15 tumours (four basal-like triple-negative [TN], eight normal-like TN, and three luminal B fHER2 negative [LB fHER2-]), two cell lines (CL, TiHo-0906, and TiHo-1403) isolated from the primary tumours (LB fHER2-) of two cats included in this study, and 13 healthy mammary tissue controls. DEGs in tumours were predominantly upregulated; dysregulation of CLs transcriptome was more extensive, including mostly downregulated genes. Cell-cycle and metabolic-related DEGs were upregulated in both tumours and CLs, including therapeutically-targetable cell cycle regulators (e.g. CCNB1, CCNB2, CDK1, CDK4, GTSE1, MCM4, and MCM5), metabolic-related genes (e.g. FADS2 and SLC16A3), heat-shock proteins (e.g. HSPH1, HSP90B1, and HSPA5), genes controlling centrosome disjunction (e.g. RACGAP1 and NEK2), and collagen molecules (e.g. COL2A1). DEGs specifically upregulated in basal-like TN tumours were involved in antigen processing and presentation, in normal-like TN tumours encoded G protein-coupled receptors (GPCRs), and in LB fHER2- tumours were associated with lysosomes, phagosomes, and endosomes formation. Downregulated DEGs in CLs were associated with structural and signalling cell surface components. Hence, our results suggest that upregulation of genes enhancing proliferation and metabolism is a common feature among FMCs and derived CLs. In contrast, the dissimilarities observed in dysregulation of membrane components highlight CLs' disconnection with the tumour microenvironment. Furthermore, recurrent and exclusive DEGs associated with dysregulated pathways might be useful for the development of prognostically and therapeutically-relevant targeted panels.

Downregulation of GTSE1 leads to the inhibition of proliferation, migration, and Warburg effect in cervical cancer by blocking LHDA expression

AIM

G2 and S phase-expressed-1 (GTSE1) has been identified to play a vital role in several kinds of cancers, but its role in cervical cancer development remains unknown. Herein, we aimed to reveal the role and underlying mechanism of GTSE1 in cervical cancer cell growth, migration, and aerobic glycolysis.

METHODS

GTSE1 expression levels in cervical cancer tissues and normal cervical tissues were determined by real time PCR and immunohistochemistry. Human short hairpin RNA was used to downregulate GTSE1 level in cervical cancer cells SiHa and HeLa cells. Colony formation, cell counting kit-8, and wound-healing assays were used for cell function evaluation. Lactate production, lactate dehydrogenase activity, and glucose concentration were tested to assess the Warburg effect.

RESULTS

GTSE1 expressions at both mRNA and protein levels were significantly elevated in cervical cancer tissues compared with normal tissues. Downregulation of GTSE1 induced significant repressions in cell colony formation, viability and migration, and Warburg effect, as well as reduced expression of lactate dehydrogenase isoform A (LDHA) at mRNA and protein levels. Additionally, downregulation of GTSE1 weakened the tumorigenesis of HeLa and SiHa cells in vivo.

CONCLUSION

This study demonstrated that downregulation of GTSE1 led to significant inhibitions in cell proliferation, migration, tumorigenesis, and Warburg effect in cervical cancer by blocking the expression of LHDA.

TEAD4 is an Immune Regulating-Related Prognostic Biomarker for Bladder Cancer and Possesses Generalization Value in Pan-Cancer

Recent studies have revealed the significant role of TEA domain family member 4 (TEAD4) in the development and progression of cancer. However, the potential role of TEAD4 in the progression of bladder cancer (BC) remains to be explored. The aim of this study was to determine whether TEAD4 could serve as a pan-cancer predictor of the prognosis for BC. Based on data mined from public databases, expression levels and clinical value of TEAD4 were identified in BC and human pan-cancers. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis was performed to detect the TEAD4 expression levels in BC cell lines. Gene Set Enrichment Analysis (GSEA) was carried out for functional analysis in BC, and the relationship between infiltrating immune cells and TEAD4 expression was evaluated by the CIBERSORT algorithm in BC and pan-cancer data. TEAD4 was overexpressed and associated with poor prognosis in BC and several types of cancers. GSEA and CIBERSORT algorithm suggested that various pathways including immune-related pathways were enriched in TEAD4 high expression group and several immunocytes infiltrated were correlated with the expression of TEAD4. This study revealed TEAD4 is an immune regulating-related predictor of prognosis for BC and has generalization value in pan-cancer.

Verteporfin induces apoptosis and reduces the stem cell-like properties in Neuroblastoma tumour-initiating cells through inhibition of the YAP/TAZ pathway

Neuroblastoma is an embryonal malignancy of early childhood arising from the embryonic sympatho-adrenal lineage of the neural crest. About half of all cases are currently classified as high-risk of disease recurrence, with an overall survival rate of less than 40% at 5 years despite intensive therapy. Recent studies on matched primary tumours and at the relapse revealed downregulation of genes transcriptionally silenced by YAP as significant association with neuroblastoma relapse. Here, we evaluated the pharmacological targeting of YAP/TAZ with the YAP/TAZ-TEAD inhibitor Verteporfin (VP) in Tumour Initiating Cells (TICs) derived from High-Risk Neuroblastoma patients. VP treatment suppresses YAP/TAZ expression, induces apoptosis and causes the re-organization of the cytoskeleton reducing cells migration and clonogenic ability. Moreover, VP reduces the percentage of side population cells and ABC transporters involved in drug resistance, and the percentage of stem cell subpopulations CD133+ and CD44⁺ of TICs. Finally, we demonstrated that VP sensitizes TICs to the standard drugs used for neuroblastoma therapy etoposide and cis-platin opening the way to use VP as drug repositioning candidate for recurrent neuroblastoma.

DNMT3A inhibits E2F1-induced arterial marker expression and impairs angiogenesis in human umbilical artery endothelial cells

Arterial marker genes EphrinB2 and HEY2 are essential for cardiovascular development and postnatal neovascularization. Our previous study confirmed that E2F1 could activate the transcription of EphrinB2 and HEY2 in human mesenchymal stem cells; however, the detailed mechanism has not been resolved yet. In this study, we focused on the interaction between E2F1 and DNMT3A, a de novo DNA methyltransferase, on regulating the expression of EphrinB2 and HEY2, and explored the potential mechanisms. Gain- and loss-of-function experiments implicated the positive effect of E2F1 on the expression of EphrinB2 and HEY2 and tube formation in human umbilical artery endothelial cells. Accumulation of DNMT3A decreased the levels of EphrinB2 and HEY2, and impaired tube formation induced by E2F1, while inhibiting DNMT3A by RNA interference augmented their expression and angiogenesis in E2F1-trasfected cells. We then asked whether the low expressions of EphrinB2 and HEY2 induced by DNMT3A are related to the methylation status of their promoters. Surprisingly, the methylation status of the CpG islands in the promoter region was not significantly affected by overexpression of exogenous DNMT3A. Furthermore, the interaction between E2F1 and DNMT3A was confirmed by co-immunoprecipitation. DNMT3A could inhibit the transcription of EphrinB2 and HEY2 promoters by affecting the binding of E2F1 to its recognition sequences as revealed by luciferase reporter assay and chromatin immunoprecipitation. These results identified a novel mechanism underlying the cooperation of DNMT3A with E2F1 on regulating target gene expression, and revealed their roles in the angiogenic process.

Molecular Mechanism of Hippo-YAP1/TAZ Pathway in Heart Development, Disease, and Regeneration

The Hippo-YAP1/TAZ pathway is a highly conserved central mechanism that controls organ size through the regulation of cell proliferation and other physical attributes of cells. The transcriptional factors Yes-associated protein 1 (YAP1) and PDZ-binding motif (TAZ) act as downstream effectors of the Hippo pathway, and their subcellular location and transcriptional activities are affected by multiple post-translational modifications (PTMs). Studies have conclusively demonstrated a pivotal role of the Hippo-YAP1/TAZ pathway in cardiac development, disease, and regeneration. Targeted therapeutics for the YAP1/TAZ could be an effective treatment option for cardiac regeneration and disease. This review article provides an overview of the Hippo-YAP1/TAZ pathway and the increasing impact of PTMs in fine-tuning YAP1/TAZ activation; in addition, we discuss the potential contributions of the Hippo-YAP1/TAZ pathway in cardiac development, disease, and regeneration.

Knockdown GTSE1 enhances radiosensitivity in non-small-cell lung cancer through DNA damage repair pathway

Radiotherapy is an important strategy for NSCLC. However, although a variety of comprehensive radiotherapy-based treatments have dominated the treatment of NSCLC, it cannot be avoided to overcome the growing radioresistance during radiotherapy. The purpose of this study was to elucidate the radiosensitizing effects of NSCLC via knockdown GTSE1 expression and its mechanism. Experiments were performed by using multiple NSCLC cells such as A549, H460 and H1299. Firstly, we found GTSE1 conferred to radioresistance via clonogenic assay and apoptosis assay. Then, we detected the level of DNA damage through comet assay and γH2AX foci, which we could clearly observe knockdown GTSE1 enhance DNA damage after IR. Furthermore, through using laser assay and detecting DNA damage repair early protein expression, we found radiation could induce GTSE1 recruited to DSB site and initiate DNA damage response. Our finding demonstrated that knockdown GTSE1 enhances radiosensitivity in NSCLC through DNA damage repair pathway. This novel observation may have therapeutic implications to improve therapeutic efficacy of radiation.

Clinical and Expression Significance of AKT1 by Co-expression Network Analysis in Endometrial Cancer

Introduction: Endometrial cancer is one of the most common uterine cancers worldwide. AKT is reported to regulate progesterone receptor B dependent transcription and angiogenesis in endometrial cancer. However, the potential mechanisms of AKT in the tumor progression of endometrial cancer remain unclear.

Methods: We used GSE72708 with gene expression profiles of AKT regulation from the GEO database. We performed GSEA analysis to explore pathway enrichments. We found that most upregulated enriched pathways in siAKT group were associated with acid metabolism and immune network. Endometrial cancer and various signaling pathways were downregulated enriched. Moreover, different molecular mechanism of regulation between progestin (R5020) and AKT was identified, which were related to VEGF signaling pathway. The hub genes were evaluated by immunohistochemical staining of endometrial cancer tissues.

Results: We screened out a total of 623 differentially expressed genes among different groups. According to weighted gene co-expression network analysis (WGCNA) method, four distinct modules were identified. We found brown module showed a very high positive correlation with siAKT group and a very high negative correlation with R5020 group. A total of six hub genes including PBK, BIRC5, AURKA, GTSE1, KNSTRN, and PSMB10 were finally identified associated with AKT1. In addition, the data also shows that the higher expression of AKT1, GTSE1, BIRC5, AURKA, and KNSTRN is significantly associate with poor prognosis of endometrial cancer.

Conclusion: Our study identified six hub genes related to the prognosis of endometrial cancer, which may provide new insights into the underlying biological mechanisms driving the tumorigenesis of endometrial cancer, especially in AKT1 regulation.

GTSE1 is involved in breast cancer progression in p53 mutation-dependent manner

Background

With the rapid development of the high throughput detection techniques, tumor-related Omics data has become an important source for studying the mechanism of tumor progression including breast cancer, one of the major malignancies worldwide. A previous study has shown that the G2 and S phase-expressed-1 (GTSE1) can act as an oncogene in several human cancers. However, its functional roles in breast cancer remain elusive.

Method

In this study, we analyzed breast cancer data downloaded from The Cancer Genome Atlas (TCGA) databases and other online database including the Oncomine, bc-GenExMiner and PROGgeneV2 database to identify the molecules contributing to the progression of breast cancer. The GTSE1 expression levels were investigated using qRT-PCR, immunoblotting and IHC. The biological function of GTSE1 in the growth, migration and invasion of breast cancer was examined in MDA-MB-231, MDA-MB-468 and MCF7 cell lines. The in vitro cell proliferative, migratory and invasive abilities were evaluated by MTS, colony formation and transwell assay, respectively. The role of GTSE1 in the growth and metastasis of breast cancer were revealed by in vivo investigation using BALB/c nude mice.

Results

We showed that the expression level of GTSE1 was upregulated in breast cancer specimens and cell lines, especially in triple negative breast cancer (TNBC) and p53 mutated breast cancer cell lines. Importantly, high GTSE1 expression was positively correlated with histological grade and poor survival. We demonstrated that GTSE1 could promote breast cancer cell growth by activating the AKT pathway and enhance metastasis by regulating the Epithelial-Mesenchymal transition (EMT) pathway. Furthermore, it could cause multidrug resistance in breast cancer cells. Interestingly, we found that GTSE1 could regulate the p53 function to alter the cell cycle distribution dependent on the mutation state of p53.

Conclusion

Our results reveal that GTSE1 played a key role in the progression of breast cancer, indicating that GTSE1 could serve as a novel biomarker to aid in the assessment of the prognosis of breast cancer.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1157-4) contains supplementary material, which is available to authorized users.

Overexpression of G2 and S phase-expressed-1 contributes to cell proliferation, migration, and invasion via regulating p53/FoxM1/CCNB1 pathway and predicts poor prognosis in bladder cancer

Bladder cancer is one of the most common urogenital tumors worldwide. The specific function and molecular mechanism of GTSE1 in bladder cancer remain unknown. In the present study, real-time quantitative polymerase chain reaction and Western blotting were used to identify GTSE1 expression in bladder cancer tissues and cells, and immunohistochemical assays were conducted to investigate GTSE1 expression in tissue microarray. Regression analyses explored the relationship between GTSE1 expression and pathological characteristics. A series of functional tests were performed to observe the effects of GTSE1 knockdown or overexpression, and the related mechanism was also performed. GTSE1 expression was significantly higher in bladder cancer tissues; overexpression of GTSE1 was positively associated with disease recurrence history, lymph node invasion, and progression. Patients with higher GTSE1 expression were more likely to experience shorter survival time, and GTSE1 expression served as a prognostic factor for the disease progression. Knockdown of GTSE1 obviously suppressed the proliferation, migration, and invasion capacity whereas increasing GTSE1 led to the opposite trend, which suggested that GTSE1 could serve as a potential therapeutic target for bladder cancer. GTSE1 overexpression in bladder cancer might participate in the regulation of FoxM1/CCNB1 expression via the induction of the transfer of p53 to cytoplasm.

Overexpression of TEAD4 correlates with poor prognosis of glioma and promotes cell invasion

This study aimed to reveal the correlation of increased TEA domain transcription factor 4 (TEAD4) expression and disease prognosis in glioma. The expression data of TEAD4 mRNA in glioma were collected from GEO database (GSE4290), and the expression of TEAD4 protein in glioma was confirmed using western blot and Immunohistochemistry. Kaplan-Meier analysis with the log-rank test was used to reveal the correlation of TEAD4 expression level and patients' survival. The effects of TEAD4 on migration and invasion were separately examined by Transwell assay and Boyden assay. Gene set enrichment analysis (GSEA) was performed to predict the possible biological function of TEAD4 in glioma. The results showed that TEAD4 mRNA and protein expression were upregulated in glioma tissues compared to normal brain tissues. Furthermore, overexpression of TEAD4 correlated with poor prognosis in glioma patients. Knockdown of TEAD4 markedly inhibited glioma cells migration and invasion in vitro. Consistent with the result that TEAD4 was associated with epithelial-mesenchymal transition (EMT) closely by GESA, knockdown of TEAD4 resulted in N-cadherin, vimentin and Slug downregulated but E-cadherin upregulated. Our study indicated that overexpression of TEAD4 may represent as a potential unfavorable marker for poor survival and prognosis in glioma. Knockdown of TEAD4 led to suppressed glioma migration and invasion.