E2F3 promotes liver cancer progression under the regulation of circ-PRKAR1B

Dexamethasone-tamoxifen combination exerts synergistic therapeutic effects in tamoxifen-resistance breast cancer cells

Tamoxifen (TAM) is a key player in estrogen receptor-positive (ER+) breast cancer (BC); however, ∼30% of patients experience relapse and a lower survival rate due to TAM resistance. TAM resistance was related to the over expression of SOX-2 gene, which is regulated by the E2F3 transcription factor in the Wnt signaling pathway. It was suggested that SOX-2 overexpression was suppressed by dexamethasone (DEX), a glucocorticoid commonly prescribed to BC patients. The aim of the present study is to explore the effect of combining DEX and TAM on the inhibition of TAM-resistant LCC-2 cells (TAMR-1) through modulating the E2F3/SOX-2-mediated Wnt signaling pathway. The effect of the combination therapy on MCF-7 and TAMR-1 cell viability was assessed. Drug interactions were analyzed using CompuSyn and SynergyFinder softwares. Cell cycle distribution, apoptotic protein expression, gene expression levels of SOX-2 and E2F3, and cell migration were also assessed. Combining DEX with TAM led to synergistic inhibition of TAMR-1 cell proliferation and migration, induced apoptosis, reduced SOX-2 and E2F3 expression and was also associated with S and G2-M phase arrest. Therefore, combining DEX with TAM may present an effective therapeutic option to overcome TAM resistance, by targeting the E2F3/SOX-2/Wnt signaling pathway, in addition to its anti-inflammatory effect.

Circ_0001495 influences the development of endometriosis through the miRNA-34c-5p/E2F3 axis

Endometriosis is a chronic gynecological condition characterized by the presence of endometrial glands and stroma outside the uterine cavity., accounting for 7% of all female malignant tumors and 20%- 30% of malignant tumors of the female reproductive system. Multiple studies have shown that circular RNA (circRNA) has the potential to become a targeted target and marker for EM. However, the roles of circ_0001495 in EM are still unclear. Our research aims to reveal the molecular mechanism of circ_0001495 in EM. In this study, RT-PCR or western blot were conducted to determine mRNA and protein expression. cell viability, proliferation, migration, invasion, and apoptosis were assessed by CCK-8, EdU, wound healing, transwell, and flow cytometry analyses, respectively. Additionally, the targeting relationship between miR-34c-5p and circ_0001495 or E2F3 was confirmed through dual-luciferase reporter gene assay. We found significant overexpression of circ_0001495 in EM tissues and cells. Knockdown of circ_0001495 inhibited the proliferation, migration and invasion of ectopic endometrial stromal cells (EESCs) and increased cell apoptosis. Moreover, we found that circ_0001495 regulated E2F3 levels by interacting with miR-34c-5p in EESC. Furthermore, in vitro, miR-34c-5p inhibition or E2F3 overexpression could attenuate the effect of circ_0001495 silencing on EM progression. In addition, the vivo experiment demonstrated that inhibition of circ_0001495 could repress the development of endometriosis by regulating the miR-34c-5p/E2F3 axis. In conclusion, our study suggested that circ_0001495 promoted EM progression in vitro and in vivo through the miR-34c-5p/E2F3 axis, which might be a potential therapeutic target for EM.

Transcription factor E2F3 activates CDC25B to regulate DNA damage and promote mitoxantrone resistance in stomach adenocarcinoma

BACKGROUND

CDC25B, as a member of the cell cycle regulating protein family, is located in the cytoplasm and is involved in the transition of the cell cycle and mitosis. CDC25B is highly expressed in various tumors and is a newly discovered oncogene. This study aimed to investigate the impact of CDC25B on mitoxantrone resistance in stomach adenocarcinoma (STAD) and its possible mechanisms.

METHODS

This study analyzed the expression of CDC25B and its potential transcription factor E2F3 in STAD, as well as the IC50 values of tumor tissues by bioinformatics analysis. Expression levels of CDC25B and E2F3 in STAD cells were measured by qRT-PCR. MTT was utilized to evaluate cell viability and IC50 values of STAD cells, and comet assay was utilized to analyze the level of DNA damage in STAD cells. Western blot was used to analyze the expression of DNA damage-related proteins. The targeting relationship between E2F3 and CDC25B was validated by dual-luciferase and ChIP assays.

RESULTS

Bioinformatics analysis and molecular experiments showed that CDC25B and E2F3 were highly expressed in STAD, and CDC25B was enriched in the mismatch repair and nucleotide excision repair pathways. The IC50 values of tumor tissues with high expression of CDC25B were relatively high. Dual-luciferase and ChIP assays confirmed that CDC25B could be transcriptionally activated by E2F3. Cell experiments revealed that CDC25B promoted mitoxantrone resistance in STAD cells by regulating DNA damage. Further research found that low expression of E2F3 inhibited mitoxantrone resistance in STAD cells by DNA damage, but overexpression of CDC25B reversed the impact of E2F3 knockdown on mitoxantrone resistance in STAD cells.

CONCLUSION

This study confirmed a novel mechanism by which E2F3/CDC25B mediated DNA damage to promote mitoxantrone resistance in STAD cells, providing a new therapeutic target for STAD treatment.

E2F3/CDCA2 reduces radiosensitivity in gastric adenocarcinoma by activating PI3K/AKT pathway

OBJECTIVES

Gastric adenocarcinoma is primarily responsible for tumor-associated deaths and its incidence is increasing global. CDCA2 is a nuclear protein binding to protein phosphatase one γ (PP1γ) and plays a pro-oncogenic role in tumors. This study aimed to elucidate the biological function of CDCA2 in gastric adenocarcinoma progression and radiosensitivity, as well as its potential mechanisms.

METHODS

Differentially expressed mRNAs in gastric adenocarcinoma were obtained by bioinformatics and upstream regulatory factors were predicted. The correlation between their expressions was analyzed. The expressions of E2F3 and CDCA2 in cells were assayed by qRT-PCR and their regulatory relationship was validated by molecular experiments. Cell viability was tested via CCK-8. Cell proliferation and survival after radiotherapy were determined by colony formation assay. The expressions of PI3K/AKT pathway-related proteins were assessed through western blot.

RESULTS

CDCA2 was significantly upregulated in gastric adenocarcinoma tissues and cells, promoted cell proliferation, and reduced radiosensitivity. The impact of CDCA2 on cell proliferation and radiosensitivity was reversed by the PI3K/AKT inhibitor. Furthermore, the upstream transcription factor of CDCA2 was found to be E2F3, which was highly expressed in gastric adenocarcinoma. The binding relationship between the two was validated by dual luciferase and ChIP experiments. The rescue experiment showed that E2F3 activated CDCA2 to drive cell proliferation and reduce radiosensitivity through PI3K/AKT pathway in gastric adenocarcinoma.

CONCLUSION

In summary, this study found that E2F3 activated CDCA2 to drive cell proliferation and reduce radiosensitivity in gastric adenocarcinoma through the PI3K/AKT pathway, suggesting that E2F3/CDCA2 axis is a new therapeutic target for gastric adenocarcinoma.

ADVANCES IN KNOWLEDGE

1. CDCA2 reduced the radiosensitivity of gastric adenocarcinoma cells;2. CDCA2 reduced the radiosensitivity of gastric adenocarcinoma cells through the PI3K/AKT pathway;3. E2F3 activated CDCA2 to reduce the radiosensitivity of gastric adenocarcinoma cells through the PI3K/AKT pathway.

Identification of metabolic biomarkers associated with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease. Metabolism-related genes significantly influence the onset and progression of the disease. Hence, it is necessary to screen metabolism-related biomarkers for the diagnosis and treatment of NAFLD patients.

METHODS

GSE48452, GSE63067, and GSE89632 datasets including nonalcoholic steatohepatitis (NASH) and healthy controls (HC) analyzed in this study were retrieved from the Gene Expression Omnibus (GEO) database. First, differentially expressed genes (DEGs) between NASH and HC samples were obtained. Next, metabolism-related DEGs (MR-DEGs) were identified by overlapping DEGs and metabolism-related genes (MRG). Further, a protein-protein interaction (PPI) network was developed to show the interaction among MR-DEGs. Subsequently, the "Least absolute shrinkage and selection operator regression" and "Random Forest" algorithms were used to screen metabolism-related genes (MRGs) in patients with NAFLD. Next, immune cell infiltration and gene set enrichment analyses (GSEA) were performed on these metabolism-related genes. Finally, the expression of metabolism-related gene was determined at the transcription level.

RESULTS

First, 129 DEGs related to NAFLD development were identified among patients with nonalcoholic steatohepatitis (NASH) and healthy control. Next, 18 MR-DEGs were identified using the Venn diagram. Subsequently, four genes, including AMDHD1, FMO1, LPL, and P4HA1, were identified using machine learning algorithms. Moreover, a regulatory network consisting of four genes, 25 microRNAs (miRNAs), and 41 transcription factors (TFs) was constructed. Finally, a significant increase in FMO1 and LPL expression levels and a decrease in AMDHD1 and P4HA1 expression levels were observed in patients in the NASH group compared to the HC group.

CONCLUSION

Metabolism-related genes associated with NAFLD were identified, containing AMDHD1, FMO1, LPL, and P4HA1, which provide insights into diagnosing and treating patients with NAFLD.

FOXN Transcription Factors: Regulation and Significant Role in Cancer

A growing number of studies have demonstrated that cancer development is closely linked to abnormal gene expression, including alterations in the transcriptional activity of transcription factors. The Forkhead box class N (FOXN) proteins FOXN1-6 form a highly conserved class of transcription factors, which have been shown in recent years to be involved in the regulation of malignant progression in a variety of cancers. FOXNs mediate cell proliferation, cell-cycle progression, cell differentiation, metabolic homeostasis, embryonic development, DNA damage repair, tumor angiogenesis, and other critical biological processes. Therefore, transcriptional dysregulation of FOXNs can directly affect cellular physiology and promote cancer development. Numerous studies have demonstrated that the transcriptional activity of FOXNs is regulated by protein-protein interactions, microRNAs (miRNA), and posttranslational modifications (PTM). However, the mechanisms underlying the molecular regulation of FOXNs in cancer development are unclear. Here, we reviewed the molecular regulatory mechanisms of FOXNs expression and activity, their role in the malignant progression of tumors, and their value for clinical applications in cancer therapy. This review may help design experimental studies involving FOXN transcription factors, and enhance their therapeutic potential as antitumor targets.

E2F3 renders an immunosuppressive tumor microenvironment in nasopharyngeal carcinoma: Involvements of the transcription activation of PRC1 and BIRC5

BACKGROUND

E2F transcription factors are well-recognized oncogenic molecules, and their correlation with immune cell infiltration has recently been reported. This work studies the impacts and mechanism of E2F transcription factor 3 (E2F3) in the growth and tumor microenvironment (TME) of nasopharyngeal carcinoma (NPC).

METHODS

Aberrantly expressed transcription factors in NPC were screened by abundant bioinformatics analyses. Gene expression in NPC cells was analyzed by reverse transcription-quantitative polymerase chain reaction and Western blot analyses. Malignant behaviors of NPC cells were analyzed by cell counting kit-8, 5-ethynyl-2'-deoxyuridine labeling, Transwell assays, and xenograft tumor models. TPA-induced THP-1 cells (macrophages) were cultured in the conditioned medium of NPC cells to mimic tumor-associated macrophages (TAMs) in vivo, and these TAMs were cocultured with CD8+ T cells. Regulation of E2F3 on protein regulator of cytokinesis 1 (PRC1) and baculoviral IAP repeat containing 5 (BIRC5) was validated by chromatin immunoprecipitation and luciferase reporter assays.

RESULTS

E2F3 was highly expressed in NPC cells, and its knockdown suppressed malignant behavior and tumorigenic ability of the cells. The E2F3 knockdown condition downregulated M2 cytokines CD163 and interleukin-10 in TAMs, which further enhanced proliferation and activation of the cocultured CD8+ T cells. E2F3 promoted transcription of PRC1 and BRIC5. Furthermore, PRC1 or BRIC5 upregulation in NPC cells restored the malignant properties of NPC cells, reprogrammed the TAMs to M2 phenotype, and suppressed the CD8+ T cell proliferation and activation.

CONCLUSION

This work suggests that E2F3 renders an immunosuppressive TME in NPC by activating PRC1 and BIRC5. Suppression of any member involved might favor tumor elimination.

Circ_001422 aggravates osteosarcoma progression through targeting miR-497-5p/E2F3 axis

Circular RNAs exert vital functions in the pathogenesis of osteosarcoma (OS). Circ_001422 has been confirmed to be involved in regulating OS progression, but its specific mechanism has not been clearly studied. This work aimed to analyze circ_001422's role in OS cell biological behaviors and the possible molecular mechanisms. This work carried out reverse transcription-quantitative polymerase chain reaction for detecting circ_001422, E2F3 and miR-497-5p levels, whereas Cell counting kit-8 together with Transwell assays for measuring cell growth, migration as well as invasion abilities. Relation of miR-497-5p with E2F3, as well as circ_001422 with miR-497-5p was analyzed through dual-luciferase reporter gene assay. Protein level was identified by western blot. According to our results, circ_001422 expression within OS tissue significantly increased compared with corresponding healthy samples. Inhibition of circ_001422 significantly decreased OS cell growth, invasion and migration. From mechanism research, miR-497-5p was proved as circ_001422's target, and E2F3 was miR-497-5p's target. Besides, miR-497-5p downregulation or E2F3 overexpression abolished circ_001422 inhibition-mediated inhibition on OS cell proliferation, invasion and migration. Collectively, this study has first suggested circ_001422's role in enhancing OS proliferation, migration as well as invasion via miR-497-5p/E2F3 axis. Our results will offer new ideas and new anti-OS targets.

Androgen receptor suppresses lung cancer invasion and increases cisplatin response via decreasing TPD52 expression

Lung cancer, as the most commonly diagnosed malignancy, still accounts for the leading cause of cancer-related deaths worldwide. The high rate of mortality and tumor recurrence has prompted clinicians and scientists to urgently explore new targets for improved treatment. Previous studies have indicated a potential role of the androgen receptor (AR) in the progression of non-small cell lung cancer (NSCLC). However, the precise mechanisms underlying this association, particularly its relation to TPD52-mediated cell invasion and cisplatin (DDP) response, have not been fully elucidated. Therefore, further investigation is necessary to gain a better understanding of these mechanisms and their potential implications for lung cancer treatment. In this study, we discovered that AR can suppress NSCLC cell invasion and increase cisplatin response by downregulating the expression of circular RNA (circRNA), specifically circ-SLCO1B7. This suppression is achieved through the direct binding of AR to the 5' promoter region of the host gene SLCO1B7. The decreased expression of circ-SLCO1B7, mediated by AR, released miR-139-5p back to the RISC (RNA induced silencing complex), where it bonds to the 3' untranslated region (3'UTR) of Tumor Protein D52 (TPD52) messenger RNA, resulting in TPD52 reduction. The in vivo data also validated the functional contribution of AR/circ-SLCO1B7/miR-139-5p/TPD52 axis to lung cancer progression. Furthermore, analysis of human NSCLC databases and clinical specimens confirmed the association of the AR/circ-SLCO1B7/miR-139-5p/TPD52 signaling pathway with NSCLC progression. Collectively, the results from our study suggest that AR can suppress lung cancer cell invasion and increase DDP response by modulating the circ-SLCO1B7/miR-139-5p/TPD52 signaling pathway. Targeting this novel signaling pathway may be a new therapeutic strategy to effectively constrain NSCLC development.

E2F3 accelerates the stemness of colon cancer cells by activating the STAT3 pathway

Introduction

Colon cancer is one of the most prevalent malignancies and causes of cancer-related deaths worldwide. Thus, further research is required to explicate the latent molecular mechanisms and look for novel biomarkers. E2F3 has been confirmed to be an oncogene in a variety of cancers. However, the particular regulation of E2F3 in colon cancer needs further investigation.

Methods

The self-renewal ability was detected through a sphere formation assay. The tumorigenic ability was measured through nude mice in vivo assay. The protein expression of genes was examined through a Western blot. The expression of E2F3 in tumor tissues was detected through an IHC assay. The resistance to cisplatin was assessed through the CCK-8 assay. The cell migration and invasion abilities were measured after upregulating or suppressing E2F3 through the Transwell assay.

Results

Results uncovered that E2F3 was upregulated in spheroid cells. In addition, E2F3 facilitates stemness in colon cancer. Moreover, E2F3 facilitated colon cancer cell migration and invasion. Finally, it was revealed that E2F3 affected the STAT3 pathway to modulate stemness in colon cancer. E2F3 served as a promoter regulator in colon cancer, aggravating tumorigenesis and stemness in colon cancer progression through the STAT3 pathway.

Conclusion

E2F3 may be a useful biomarker for anticancer treatment in colon cancer.

Transcriptome analysis of newly established carboplatin-resistant ovarian cancer cell model reveals genes shared by drug resistance and drug-induced EMT

BACKGROUND

In ovarian cancer (OC) therapy, even initially responsive patients develop drug resistance.

METHODS

Here, we present an OC cell model composed of variants with differing degrees of acquired resistance to carboplatin (CBP), cross-resistance to paclitaxel, and CBP-induced metastatic properties (migration and invasion). Transcriptome data were analysed by two approaches identifying differentially expressed genes and CBP sensitivity-correlating genes. The impact of selected genes and signalling pathways on drug resistance and metastatic potential, along with their clinical relevance, was examined by in vitro and in silico approaches.

RESULTS

TMEM200A and PRKAR1B were recognised as potentially involved in both phenomena, also having high predictive and prognostic values for OC patients. CBP-resistant MES-OV CBP8 cells were more sensitive to PI3K/Akt/mTOR pathway inhibitors Rapamycin, Wortmannin, SB216763, and transcription inhibitor Triptolide compared with parental MES-OV cells. When combined with CBP, Rapamycin decreased the sensitivity of parental cells while Triptolide sensitised drug-resistant cells to CBP. Four PI3K/Akt/mTOR inhibitors reduced migration in both cell lines.

CONCLUSIONS

A newly established research model and two distinct transcriptome analysis approaches identified novel candidate genes enrolled in CBP resistance development and/or CBP-induced EMT and implied that one-gene targeting could be a better approach than signalling pathway inhibition for influencing both phenomena.

Identification of Methylation Signatures and Rules for Sarcoma Subtypes by Machine Learning Methods

Sarcoma, the second common type of solid tumor in children and adolescents, has a wide variety of subtypes that are often not properly diagnosed at an early stage, leading to late metastases and causing serious loss of life and property to patients and families. It exhibits a high degree of heterogeneity at the cellular, molecular, and epigenetic levels, where DNA methylation has been proposed to play a role in the diagnosis of sarcoma subtypes. Thus, this study is aimed at finding potential biomarkers at the DNA methylation level to distinguish different sarcoma subtypes. A machine learning process was designed to analyse sarcoma samples, each of which was represented by lots of methylation sites. Irrelevant sites were removed using the Boruta method, and remaining sites related to the target variables were kept for further analyses. Afterward, three feature ranking methods (LASSO, LightGBM, and MCFS) were adopted to rank these features, and six classification models were constructed by combining incremental feature selection and two classification algorithms (decision tree and random forest). Among these models, the performance of RF model was higher than that of DT model under all three ranking conditions. The specific expression of genes obtained from the annotation of highly correlated methylation site features, such as PRKAR1B, INPP5A, and GLI3, was proven to be associated with sarcoma by publications. Moreover, the quantitative rules obtained by decision tree algorithm helped us to understand the essential differences between various sarcoma types and classify sarcoma subtypes, providing a new means of clinical identification and determining new therapeutic targets.

Hsa_hsa_circ_0081069 promotes the progression of colorectal cancer through sponging miR-665 and regulating E2F3 expression

BACKGROUND

Circular RNAs (circRNAs) have been implicated in the initiation and development of various cancers. This study explored the potential contribution of hsa_hsa_circ_0081069 in the progression of colorectal cancer (CRC).

METHODS

The gene expression was analyzed by qRT-PCR. Functional roles of hsa_circ_0081069 were examined by shRNA-mediated silencing using CCK-8 proliferation assay, Transwell migration and invasion assay, tube formation assay. The tumorigenesis and metastasis of CRC cells were assess in a xenograft mouse model.

RESULTS

Hsa_circ_0081069 was significantly upregulated in CRC tissues and cells. Hsa_circ_0081069 knockdown suppressed the proliferation, migration and invasion in CRC cells, as well as the angiogenesis. Silencing hsa_circ_0081069 also impaired the tumorigenesis of CRC cells in a xenograft mouse model. Furthermore, miR-665 was identified as an interacting partner of hsa_circ_0081069, which was negatively regulated by hsa_circ_0081069. miR-665 targeted the mRNA of E2F3 to suppress its expression. We further demonsatred that miR-665/E2F3 axis mediated the functional role of hsa_circ_0081069 in regulating the malignant phenotype of CRC cells.

CONCLUSIONS

Collectively, our study suggests that hsa_circ_0081069 could serve as a prognostic marker in progression of CRC. Targeting hsa_circ_0081069 and miR-665/E2F3 axis could serve as potential therapeutic strategies for CRC treatment.