NEK2 promotes the migration, invasion, proliferation of ESCC and mediates ESCC immunotherapy

Purpose

Esophageal squamous cell carcinoma (ESCC) is a disease with a high incidence rate and high mortality worldwide. The Never in Mitosis A (NIMA) family member NIMA-related kinase 2 (NEK2) plays an important role in mitosis. However, the role of NEK2 in the pathogenesis of ESCC remains unclear.

Patients and methods

The expression and function of NEK2 in TCGA and GEO data sets were analyzed by bioinformatics. We verified the expression of NEK2 in ESCC tissues and cell lines by Western blotting and immunohistochemical methods and further explored the relationship between tumor stage and NEK2 expression. The differences in NEK2 expression and survival in patients with EC were verified by bioinformatics analysis. ESCC cell lines with stable knockdown of NEK2 were established by lentivirus-mediated shRNA delivery. The effects of NEK2 on ESCC cells were analyzed on the cytological level with assays including CCK-8, EdU, cell scratch, Transwell migration and invasion, colony formation, flow cytometry and apoptosis assays. Tumor growth was measured in a mouse xenograft model.

Results

We found that NEK2 is highly expressed in ESCC tissues and ESCC cells and that the high expression of NEK2 is associated with poor tumor healing. Knockdown of the NEK2 gene inhibits the migration, proliferation, invasion and cell cycle of ESCC cells. Biologic analysis shows that NEK2 is involved in biological processes such as progression and apoptosis of esophageal cancer, and is related to E2F.Mechanistically, NEK2 knockdown decreases the expression levels of E2F1 and IGF2. NEK2 competes with the transcription factor E2F1 to bind CDC20, resulting in decreased degradation and increased expression of E2F1. IGF2 expression is also increased, which promotes the expression of thymidylate synthase, further promoting the drug resistance of ESCC cells. NEK2 is associated with immune infiltration in esophageal cancer.

Conclusion

NEK2 is highly expressed in ESCC and can promote the migration, proliferation and invasion of ESCC cells. NEK2 mediates ESCC immunotherapy.

E2F transcription factors promote tumorigenicity in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers with limited treatment options, illustrating an urgent need to identify new drugable targets in PDACs.

OBJECTIVE

Using the similarities between tumor development and normal embryonic development, which is accompanied by rapid cell expansion, we aimed to identify and characterize embryonic signaling pathways that were reinitiated during tumor formation and expansion.

METHODS AND RESULTS

Here, we report that the transcription factors E2F1 and E2F8 are potential key regulators in PDAC. E2F1 and E2F8 RNA expression is mainly localized in proliferating cells in the developing pancreas and in malignant ductal cells in PDAC. Silencing of E2F1 and E2F8 in PANC-1 pancreatic tumor cells inhibited cell proliferation and impaired cell spreading and migration. Moreover, loss of E2F1 also affected cell viability and apoptosis with E2F expression in PDAC tissues correlating with expression of apoptosis and mitosis pathway genes, suggesting that E2F factors promote cell cycle regulation and tumorigenesis in PDAC cells.

CONCLUSION

Our findings illustrate that E2F1 and E2F8 transcription factors are expressed in pancreatic progenitor and PDAC cells, where they contribute to tumor cell expansion by regulation of cell proliferation, viability, and cell migration making these genes attractive therapeutic targets and potential prognostic markers for pancreatic cancer.

CENPK orchestrates ovarian cancer progression via GOLPH3-Mediated activation of mTOR signaling

Ovarian cancer stands as a formidable clinical challenge, with limited therapeutic options. This investigation delves into the intricate molecular mechanisms governing ovarian cancer progression and uncovers Centromere Protein K (CENPK) as a central figure in disease pathogenesis. Elevated CENPK levels within ovarian cancer tissues conspicuously align with adverse clinical outcomes, positioning CENPK as a promising prognostic biomarker. Deeper exploration reveals a direct transcriptional connection between CENPK and the E2F1 transcription factor and clearly establishes E2F1's role as the master regulator of CENPK expression in ovarian cancer. Our inquiry revealing a suppression of tumor-promoting signaling pathways, most notably the mTOR pathway, upon CENPK silencing. Intriguingly, CENPK renders ovarian cancer cells more responsive to the mTOR inhibitor rapamycin, introducing a promising avenue for therapeutic intervention. In summation, our study unravels the multifaceted role of CENPK in ovarian cancer progression. It emerges as a prognostic indicator, a pivotal mediator of cell proliferation and tumorigenicity, and a regulator of the mTOR pathway, shedding light on potential therapeutic avenues for this formidable disease.

Curcumin suppresses the malignant phenotype of laryngeal squamous cell carcinoma through downregulating E2F1 to inhibit FLNA

Curcumin is a kind of polyphenol substance extracted from the rhizome of Curcuma longa. Because of its good biological activity and pharmacological effects, it has been used in anti-tumor research. The aim of this study was to investigate the anti-cancer mechanism of curcumin on laryngeal squamous cell carcinoma (LSCC). Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to check the expression level of transcription factor E2F1 (E2F1) and filamin A (FLNA) mRNA. E2F1 and FLNA protein and proliferation-associated protein were detected through western blot. Cell viability was showed by MTT assay, and flow cytometry was used to exhibit cell cycle distribution and cell apoptosis. Tube formation assay was used to detect the angiogenesis ability of cells. Transwell was used as a method to observe cell migration and invasion. The online website JASPAR predicted the binding site of E2F1 and FLNA promoter, and chromatin immunoprecipitation (ChIP) and dual-luciferase report experiment verified the combination. Curcumin treatment made LSCC cells viability reduce, cell cycle retardant, angiogenesis decrease, metastasis inhibition and apoptosis increase. And curcumin treatment could downregulate the expression of E2F1, and E2F1 overexpression would reverse the influence of curcumin treatment in LSCC cells. Moreover, E2F1 could bind to FLAN promoter and promote FLNA expression. The expression level of FLNA was higher in LSCC tissue and cells compared with normal tissue and cells. E2F1 knockdown inhibited malignant phenotype of LSCC cells, which would be reversed by FLNA addition. In addition, FLNA had high level in LSCC tissue and cells. Curcumin regulated FLNA expression via inhibiting E2F1. Finally, in vivo assay showed that curcumin inhibition restrained LSCC tumor formation. Curcumin downregulated FLNA expression through inhibiting E2F1, thereby suppressing the malignant phenotype and angiogenesis of LSCC cells, which was a new regulatory pathway in LSCC.

E2F transcription factor-1 modulates expression of glutamine metabolic genes in mouse embryonic fibroblasts and uterine sarcoma cells

Metabolic reprogramming is considered as a hallmark of cancer and is clinically exploited as a novel target for therapy. The E2F transcription factor-1 (E2F1) regulates various cellular processes, including proliferative and metabolic pathways, and acts, depending on the cellular and molecular context, as an oncogene or tumor suppressor. The latter is evident by the observation that E2f1-knockout mice develop spontaneous tumors, including uterine sarcomas. This dual role warrants a detailed investigation of how E2F1 loss impacts metabolic pathways related to cancer progression. Our data indicate that E2F1 binds to the promoter of several glutamine metabolism-related genes. Interestingly, the expression of genes in the glutamine metabolic pathway were increased in mouse embryonic fibroblasts (MEFs) lacking E2F1. In addition, we confirm that E2f1-/- MEFs are more efficient in metabolizing glutamine and producing glutamine-derived precursors for proliferation. Mechanistically, we observe a co-occupancy of E2F1 and MYC on glutamine metabolic promoters, increased MYC binding after E2F1 depletion and that silencing of MYC decreased the expression of glutamine-related genes in E2f1-/- MEFs. Analyses of transcriptomic profiles in 29 different human cancers identified uterine sarcoma that showed a negative correlation between E2F1 and glutamine metabolic genes. CRISPR/Cas9 knockout of E2F1 in the uterine sarcoma cell line SK-UT-1 confirmed elevated glutamine metabolic gene expression, increased proliferation and increased MYC binding to glutamine-related promoters upon E2F1 loss. Together, our data suggest a crucial role of E2F1 in energy metabolism and metabolic adaptation in uterine sarcoma cells.

Identification of arnicolide C as a novel chemosensitizer to suppress mTOR/E2F1/FANCD2 axis in non-small cell lung cancer

BACKGROUND AND PURPOSE

The mammalian target of rapamycin (mTOR) pathway plays critical roles in intrinsic chemoresistance by regulating Fanconi anaemia complementation group D2 (FANCD2) expression. However, the mechanisms by which mTOR regulates FANCD2 expression and related inhibitors are not clearly elucidated. Extracts of Centipeda minima (C. minima) showed promising chemosensitizing effects by inhibiting FANCD2 activity. Here, we have aimed to identify the bioactive chemosensitizer in C. minima extracts and elucidate its underlying mechanism.

EXPERIMENTAL APPROACH

The chemosensitizing effects of arnicolide C (ArC), a bioactive compound in C. minima, on non-small cell lung cancer (NSCLC) were investigated using immunoblotting, immunofluorescence, flow cytometry, the comet assay, small interfering RNA (siRNA) transfection and animal models. The online SynergyFinder software was used to determine the synergistic effects of ArC and chemotherapeutic drugs on NSCLC cells.

KEY RESULTS

ArC had synergistic cytotoxic effects with DNA cross-linking drugs such as cisplatin and mitomycin C in NSCLC cells. ArC treatment markedly decreased FANCD2 expression in NSCLC cells, thus attenuating cisplatin-induced FANCD2 nuclear foci formation, leading to DNA damage and apoptosis. ArC inhibited the mTOR pathway and attenuated mTOR-mediated expression of E2F1, a critical transcription factor of FANCD2. Co-administration of ArC and cisplatin exerted synergistic anticancer effects in the A549 xenograft mouse model by suppressing mTOR/FANCD2 signalling in tumour tissues.

CONCLUSION AND IMPLICATIONS

ArC suppressed DNA cross-linking drug-induced DNA damage response by inhibiting the mTOR/E2F1/FANCD2 signalling axis, serving as a chemosensitizing agent. This provides insight into the anticancer mechanisms of ArC and offers a potential combinatorial anticancer therapeutic strategy.

E2F1 promotes cell migration in hepatocellular carcinoma via FNDC3B

FNDC3B (fibronectin type III domain containing 3B) is highly expressed in hepatocellular carcinoma (HCC) and other cancer types, and fusion genes involving FNDC3B have been identified in HCC and leukemia. Growing evidence suggests the significance of FNDC3B in tumorigenesis, particularly in cell migration and tumor metastasis. However, its regulatory mechanisms remain elusive. In this study, we employed bioinformatic, gene regulation, and protein-DNA interaction screening to investigate the transcription factors (TFs) involved in regulating FNDC3B. Initially, 338 candidate TFs were selected based on previous chromatin immunoprecipitation (ChIP)-seq experiments available in public domain databases. Through TF knockdown screening and ChIP coupled with Droplet Digital PCR assays, we identified that E2F1 (E2F transcription factor 1) is crucial for the activation of FNDC3B. Overexpression or knockdown of E2F1 significantly impacts the expression of FNDC3B. In conclusion, our study elucidated the mechanistic link between FNDC3B and E2F1. These findings contribute to a better understanding of FNDC3B in tumorigenesis and provide insights into potential therapeutic targets for cancer treatment.

Regulation of Cell Cycle Progression through RB Phosphorylation by Nilotinib and AT-9283 in Human Melanoma A375P Cells

BCR-ABL tyrosine kinase inhibitors are commonly employed for the treatment of chronic myeloid leukemia, yet their impact on human malignant melanoma remains uncertain. In this study, we delved into the underlying mechanisms of specific BCR-ABL tyrosine kinase inhibitors (imatinib, nilotinib, ZM-306416, and AT-9283) in human melanoma A375P cells. We first evaluated the influence of these inhibitors on cell growth using cell proliferation and wound-healing assays. Subsequently, we scrutinized cell cycle regulation in drug-treated A375P cells using flow cytometry and Western blot assays. Notably, imatinib, nilotinib, ZM-306416, and AT-9283 significantly reduced cell proliferation and migration in A375P cells. In particular, nilotinib and AT-9283 impeded the G1/S transition of the cell cycle by down-regulating cell cycle-associated proteins, including cyclin E, cyclin A, and CDK2. Moreover, these inhibitors reduced RB phosphorylation, subsequently inhibiting E2F transcriptional activity. Consequently, the expression of the E2F target genes (CCNA2, CCNE1, POLA1, and TK-1) was markedly suppressed in nilotinib and AT9283-treated A375P cells. In summary, our findings suggest that BCR-ABL tyrosine kinase inhibitors may regulate the G1-to-S transition in human melanoma A375P cells by modulating the RB-E2F complex.

Analysis of E2F1 single-nucleotide polymorphisms reveals deleterious non-synonymous substitutions that disrupt E2F1-RB protein interaction in cancer

Cancer is a medical condition that is caused by the abnormal growth and division of cells, leading to the formation of tumors. The E2F1 and RB pathways are critical in regulating cell cycle, and their dysregulation can contribute to the development of cancer. In this study, we analyzed experimentally reported SNPs in E2F1 and assessed their effects on the binding affinity with RB. Out of 46, nine mutations were predicted as deleterious, and further analysis revealed four highly destabilizing mutations (L206W, R232C, I254T, A267T) that significantly altered the protein structure. Molecular docking of wild-type and mutant E2F1 with RB revealed a docking score of -242 kcal/mol for wild-type, while the mutant complexes had scores ranging from -217 to -220 kcal/mol. Molecular simulation analysis revealed variations in the dynamics features of both mutant and wild-type complexes due to the acquired mutations. Furthermore, the total binding free energy for the wild-type E2F1-RB complex was -64.89 kcal/mol, while those of the L206W, R232C, I254T, and A267T E2F1-RB mutants were -45.90 kcal/mol, -53.52 kcal/mol, -55.67 kcal/mol, and -61.22 kcal/mol, respectively. Our study is the first to extensively analyze E2F1 gene mutations and identifies candidate mutations for further validation and potential targeting for cancer therapeutics.

E2F1 Mediates Traumatic Brain Injury and Regulates BDNF-AS to Promote the Progression of Alzheimer's Disease

Traumatic brain injury (TBI) is one of the important risk factors for the development of Alzheimer's disease (AD). However, the molecular mechanism by which TBI promotes the progression of AD is not elucidated. In this study, we showed that the abnormal production of E2F1 is a major factor in promoting the neuropathological and cognitive deterioration of AD post-TBI. We found that repeated mild TBI can aggravate the neuropathology of AD in APP/PS1 mice. At the same time, the co-expression of E2F1 and beta-site APP cleaving enzyme 1 (BACE1) was upregulated when the mouse hippocampus was dissected. BACE1 is recognized as a rate-limiting enzyme for the production of Aβ. Here, we speculate that E2F1 may play a role in promoting BACE1 expression in AD. Therefore, we collected peripheral blood from patients with AD. Interestingly, there is a positive correlation between E2F1 and brain-derived neurotrophic factor-antisense (BDNF-AS), whereas BDNF-AS in AD can promote the expression of BACE1 and exhibit a neurotoxic effect. We established a cell model and found a regulatory relationship between E2F1 and BDNF-AS. Therefore, based on our results, we concluded that E2F1 regulates BDNF-AS, promotes the expression of BACE1, and affects the progression of AD. Furthermore, E2F1 mediates the TBI-induced neurotoxicity of AD.

The association of E2F1 and E2F2 single nucleotide polymorphisms with laryngeal squamous cell carcinoma pathomorphological features

BACKGROUND

Laryngeal squamous cell carcinoma (LSCC) is one of the most common types of cancer in the upper respiratory tract. It is well-known that it has a high mortality rate and poor prognosis in advanced stages. There are well-known risk factors for LSCC, though new specific and prognostic blood-based markers for LSCC development and prognosis are essential. The current study aimed to evaluate the impact of four different single nucleotide polymorphisms (SNPs), E2F1 (rs3213183 and rs3213180) and E2F2 (rs2075993 and rs3820028), on LSCC development, morphological features, and patient 5-year survival rate.

METHODS

A total of 200 LSCC patients and 200 controls were included in this study; both groups were matched by age and sex. In the present study, we analyzed four single nucleotide polymorphisms (SNPs) in the genes E2F1 (rs3213183 and rs3213180) and E2F2 (rs2075993 and rs3820028) and evaluated their associations with the risk of LSCC development, its clinical and morphological manifestation, and patients 5-year survival rate. Genotyping was carried out using RT-PCR.

RESULTS

None of the analyzed SNPs showed a direct association with LSCC development. E2F2 rs2075993 G allele carriers (OR = 4.589, 95% CI 1.050-20.051, p = 0.043) and rs3820028 A allele carriers (OR = 4.750, 95% CI 1.088-20.736, p = 0.038) had a statistically significantly higher risk for poor differentiated or undifferentiated LSCC than non-carriers. E2F1 rs3213180 GC heterozygotes were found to have a 3.7-fold increased risk for lymph node involvement (OR = 3.710, 95% CI 1.452-9.479, p = 0.006). There was no statistically significant association between investigated SNPs and patient 5-year survival rate.

CONCLUSIONS

The present study indicates that E2F2 rs2075993 and rs3820028 impact LSCC differentiation, whereas E2F1 rs3213180 - on lymph node involvement.

Transcriptional mechanism of E2F1/TFAP2C/NRF1 in regulating KANK2 gene in nephrotic syndrome

The mortality rate linked with nephrotic syndrome (NS) is quite high. The renal tubular injury influences the response of NS patients to steroid treatment. KN motif and ankyrin repeat domains 2 (KANK2) regulates actin polymerization, which is required for renal tubular cells to maintain their function. In this study, we found that the levels of KANK2 in patients with NS were considerably lower than those in healthy controls, especially in NS patients with acute kidney injury (AKI). To get a deeper understanding of the KANK2 transcriptional control mechanism, the core promoter region of the KANK2 gene was identified. KANK2 was further found to be positively regulated by E2F Transcription Factor 1 (E2F1), Transcription Factor AP-2 Gamma (TFAP2C), and Nuclear Respiratory Factor 1 (NRF1), both at mRNA and protein levels. Knocking down E2F1, TFAP2C, or NRF1 deformed the cytoskeleton of renal tubular cells and reduced F-actin content. EMSA and ChIP assays confirmed that all three transcription factors could bind to the upstream promoter transcription site of KANK2 to transactivate KANK2 in renal tubular epithelial cells. Our study suggests that E2F1, TFAP2C, and NRF1 play essential roles in regulating the KANK2 transcription, therefore shedding fresh light on the development of putative therapeutic options for the treatment of NS patients.

E2F1 Reduces Sorafenib's Sensitivity of Esophageal Carcinoma Cells via Modulating the miR-29c-3p/COL11A1 Signaling Axis

OBJECTIVE

Esophageal carcinoma (ESCA) is a common malignancy characterized by high morbidity and mortality. Our work managed to dissect the modulatory mechanism of E2F1/miR-29c-3p/COL11A1 in the malignant progression and sensitivity of ESCA cells to sorafenib.

METHODS

Via bioinformatics approaches, we identified the target miRNA. Subsequently, CCK-8, cell cycle analysis, and flow cytometry were used to check the biological influences of miR-29c-3p on ESCA cells. TransmiR, mirDIP, miRPathDB, and miRDB databases were used as tools for the prediction of upstream transcription factors and downstream genes of miR-29c-3p. The targeting relationship of genes was detected via RNA immunoprecipitation and chromatin immunoprecipitation, which was further validated by dual-luciferase assay. Finally, in vitro experiments revealed the way E2F1/miR-29c-3p/COL11A1 affected sorafenib's sensitivity, and in vivo experiments were used to verify the way E2F1 and sorafenib impacted ESCA tumor growth.

RESULTS

miR-29c-3p, downregulated in ESCA, could suppress ESCA cell viability, arrest the cell cycle in the G0/G1 phase, and impel apoptosis. E2F1 was found to be upregulated in ESCA and it could abate the transcriptional activity of miR-29c-3p. COL11A1 was found to be a downstream target of miR-29c-3p to enhance cell viability, induce cell cycle arrest in S phase, and constrain apoptosis. Cellular and animal experiments together demonstrated that E2F1 abated the sorafenib's sensitivity of ESCA cells via miR-29c-3p/COL11A1.

CONCLUSION

E2F1 affected the viability, cell cycle, and apoptosis of ESCA cells by modulating miR-29c-3p/COL11A1, and it attenuated the sensitivity of ESCA cells to sorafenib, shedding new light on the treatment of ESCA.

LncRNA LINC01703 promotes the proliferation, migration, and invasion of colorectal cancer by activating PI3K/AKT pathway

The role of LINC01703 in cancers, especially in colorectal cancer (CRC), is still largely unclear. Bioinformatics prediction, real-time quantitative polymerase chain reaction (RT-qPCR), 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assay, colony formation assay, Transwell assays, in vivo animal experiments, IF, luciferase reporter assay, and Western blot were carried out for the exploration of the potential involvement and underlying molecular mechanisms of LINC01703 in CRC cells. The results showed that LINC01703 appeared upregulated in CRC and was linked to poor prognosis. LINC01703 acted as an oncogene in both in vitro and in vivo CRC cell environments. LINC01703 activated the PI3K/AKT signaling pathway by mediating the miR-205-5p/E2F1 axis in CRC. In summary, LINC01703 possesses an oncogenic function and can be a possible biomarker or target to treat CRC.

E2F1 rs3213150 polymorphism influences cytarabine sensitivity and prognosis in patients with acute myeloid leukemia

Cytarabine (Ara-C) plays an irreplaceable role in the treatment of acute myeloid leukemia (AML). However, there are significant differences in efficacy among patients. Our previous studies found that E2F1 rs3213150 polymorphism was associated with remission rate of Ara-C chemotherapy, but the specific mechanism is not clear. This study aimed to further confirm the correlation between E2F1 rs3213150 polymorphism and Ara-C resistance and prognosis in AML patients, and to provide valuable information for elucidating the molecular mechanisms involved.

METHODS

Rs3213150 genotyping was performed in 922 AML patients by Sanger sequencing, and the effects of different genotypes on chemosensitivity and prognosis were analyzed by Logistic regression and Cox regression. Meanwhile, a prediction model of Ara-C chemotherapy resistance was established. The impact of rs3213150 polymorphism on E2F1 expression level was determined by luciferase reporter gene assay, and differentially expressed genes between patients with different genotypes were identified by RNA sequencing.

RESULTS

Compared with rs3213150 G allele carriers, patients with AA genotype had more obvious Ara-C resistance (41.94% vs. 27.94%, P = 0.002), shorter overall survival (529 d vs. 644 d, P = 0.008) and disease-free survival (519 d vs. 556 d, P = 0.023). Rs3213150G > A mutation resulted in decreased E2F1 expression.

CONCLUSION

E2F1 rs3213150 polymorphism influences the chemosensitivity and prognosis of Ara-C in Chinese AML patients.

Isoliquiritigenin suppresses the progression of malignant melanoma via targeting H2A.Z.1-E2F1 pathway

Cutaneous melanoma is one of the most prevalent tumors, and it is still a huge challenge in the current clinical treatment. Isoliquiritigenin (ISL), which is isolated from Glycyrrhiza uralensis Fisch., has been reported for its anti-tumor effect. However, the underlying mechanism and targets of ISL are still not be revealed clearly. In this study, differentiallyexpressedproteins were identified bylabel-free quantitative mass spectrometry. Two isoforms of the histone variant H2A.Z, including H2A.Z.1 and H2A.Z.2, were significantly down regulated after administration of ISL in melanoma. H2A.Z.1 was highly expressed in melanoma and correlated with poor prognosis of melanoma. The expression of H2A.Z was inhibited by ISL in a concentration-dependent manner. Overexpression of H2A.Z.1 in melanoma cell lines partly restored the repressed cell proliferation and cell cycle by ISL. Moreover, E2F1 was identified as one downstream target of H2A.Z.1, which was also highly expressed in melanoma and correlated with poor prognosis of melanoma. Furthermore, in vivo assays validated the inhibitory role of ISL in melanoma proliferation and the expression of H2A.Z.1 and E2F1.Aboveall,it is indicated that ISL inhibit melanoma proliferation via targeting H2A.Z.1-E2F1 pathway. These findings explain the anti-tumor mechanism of ISL and provide potential therapeutic targets for melanoma.

Logic-based modeling and drug repurposing for the prediction of novel therapeutic targets and combination regimens against E2F1-driven melanoma progression

Melanoma presents increasing prevalence and poor outcomes. Progression to aggressive stages is characterized by overexpression of the transcription factor E2F1 and activation of downstream prometastatic gene regulatory networks (GRNs). Appropriate therapeutic manipulation of the E2F1-governed GRNs holds the potential to prevent metastasis however, these networks entail complex feedback and feedforward regulatory motifs among various regulatory layers, which make it difficult to identify druggable components. To this end, computational approaches such as mathematical modeling and virtual screening are important tools to unveil the dynamics of these signaling networks and identify critical components that could be further explored as therapeutic targets. Herein, we integrated a well-established E2F1-mediated epithelial-mesenchymal transition (EMT) map with transcriptomics data from E2F1-expressing melanoma cells to reconstruct a core regulatory network underlying aggressive melanoma. Using logic-based in silico perturbation experiments of a core regulatory network, we identified that simultaneous perturbation of Protein kinase B (AKT1) and oncoprotein murine double minute 2 (MDM2) drastically reduces EMT in melanoma. Using the structures of the two protein signatures, virtual screening strategies were performed with the FDA-approved drug library. Furthermore, by combining drug repurposing and computer-aided drug design techniques, followed by molecular dynamics simulation analysis, we identified two potent drugs (Tadalafil and Finasteride) that can efficiently inhibit AKT1 and MDM2 proteins. We propose that these two drugs could be considered for the development of therapeutic strategies for the management of aggressive melanoma.

Exosomes Derived from E2F1-/- Adipose-Derived Stem Cells Promote Skin Wound Healing via miR-130b-5p/TGFBR3 Axis

Background

Skin wound is a widespread health problem and brings extraordinary burdens to patients. Exosomes derived from adipose-derived stem cells (ADSC-Exos) are considered promising strategies for repairing skin wounds. E2F1 is a member of the E2F family of transcription factors involved in cell growth and apoptosis. E2F1 deficiency in mice enhances wound healing by improving collagen deposition and angiogenesis. Additionally, E2F1 can regulate the transcription and paracrine activity of multiple miRNAs, which will inevitably reshape the paracrine expression profile of ADSC-Exos. This study aimed to investigate the impact of transcription factor E2F1 deficiency on the functions of ADSC-Exos in promoting wound healing.

Methods

First, we obtained ADSCs from subcutaneous adipose tissues of WT and E2F1-/- C57BL/6 mice and separated their exosomes, denoted as ADSCWT-Exos and ADSCE2F1-/--Exos. The wound healing effects of ADSCWT-Exos and ADSCE2F1-/--Exos in full-thickness skin wound models were investigated by wound images, H&E staining, and immunohistochemical staining. For the in vitro study, the abilities of ADSCWT-Exos and ADSCE2F1-/--Exos to promote cell activities, collagen formation, and angiogenesis were evaluated. The potential mechanism by which ADSCE2F1-/--Exos promote wound healing was determined by miRNA sequencing, ChIP‒qPCR, and dual-luciferase assays.

Results

ADSCE2F1-/--Exos accelerated wound healing by promoting collagen formation and angiogenesis. As a result, compared with the lower wound healing rate of 30.5% within 7 days in the control group and 42.3% in the ADSCWT-Exo group, ADSCE2F1-/--Exos significantly increased the wound healing rate to 72.5%. In vitro, ADSCE2F1-/--Exos activated the function of fibroblasts and vascular endothelial cells. The loss of E2F1 promoted miR-130b-5p expression in ADSCE2F1-/--Exos through transcriptional regulation. MiRNA high-throughput sequencing identified 12 differently expressed miRNAs between ADSCE2F1-/- and ADSCWT. ADSCE2F1-/--Exos enhanced fibroblast activities via the miR-130b-5p/TGFBR3 axis and TGF-β activation.

Conclusion

Our results indicated that ADSCE2F1-/--Exos effectively promoted wound healing by regulating the miR-130b-5p/TGFBR3 axis, thus providing a novel strategy of gene-engineered stem cell exosomes for accelerating wound healing.

Nonstructural maintenance of chromatin condensin I complex subunit G promotes the progression of glioblastoma by facilitating Poly (ADP-ribose) polymerase 1-mediated E2F1 transactivation

BACKGROUND

Nonstructural maintenance of chromatin condensin I complex subunit G (NCAPG), also known as non-structural maintenance of chromosomes condensin I complex subunit G, is mitosis-related protein that widely existed in eukaryotic cells. Increasing evidence has demonstrated that aberrant NCAPG expression was strongly associated with various tumors. However, little is known about the function and mechanism of NCAPG in glioblastoma (GBM).

METHODS

The expression and prognostic value of NCAPG were detected in the clinical databases and tumor samples. The function effects of NCAPG downregulation or overexpression were evaluated in GBM cell proliferation, migration, invasion, and self-renewal in vitro and in tumor growth in vivo. The molecular mechanism of NCAPG was researched.

RESULTS

We identified that NCAPG was upregulated in GBM and associated with poor prognosis. Loss of NCAPG suppressed the progression of GBM cells in vitro and prolonged survival in mouse models of GBM in vivo. Mechanistically, we revealed that NCAPG positively regulated E2F transcription factor 1 (E2F1) pathway activity. By directly interacting with Poly (ADP-ribose) polymerase 1, a co-activator of E2F1, and facilitating the PARP1-E2F1 interaction to activate E2F1 target gene expression. Intriguingly, we also discovered that NCAPG functioned as a downstream target of E2F1, which was proved by the ChIP and Dual-Luciferase results. Comprehensive data mining and immunocytochemistry analysis revealed that NCAPG expression was positively associated with the PARP1/E2F1 signaling axis.

CONCLUSIONS

Our findings indicate that NCAPG promotes GBM progression by facilitating PARP1-mediated E2F1 transactivation, suggesting that NCAPG is a potential target for anticancer therapy.

Mechanism of E2F1 in the proliferation, migration, and invasion of endometrial carcinoma cells via the regulation of BMI1 transcription

BACKGROUND

Endometrial carcinoma (EC) is the most prevalent gynecological cancer. Transcription factor (TF) regulates a large number of downstream target genes and is a key determinant of all physiological activities, including cell proliferation, differentiation, apoptosis, and cell cycle. The transcription factor E2F1 shows prominent roles in EC. BMI1 is a member of Polycomb suppressor Complex 1 (PRC1) and has been shown to be associated with EC invasiveness. It is currently unclear whether E2F1 can participate in the proliferation, migration, and invasion processes of EC cells by regulating BMI1 transcription.

OBJECTIVE

We investigated whether E2F1 could participate in the proliferation, migration, and invasion processes of EC cells by regulating BMI1 transcription, in order to further clarify the pathogenesis and etiology of EC, and provide reference for identifying potential therapeutic targets and developing effective prevention and treatment strategies for this disease.

METHODS

Human endometrial epithelial cells (hEECs) and human EC cell lines were selected. E2F1 expression was assessed by Western blot. E2F1 was silenced in AN3CA or overexpressed in HEC-1 by transfections, or E2F1 was silenced and BMI1 was overexpressed in AN3CA by cotransfection. Cell proliferation, migration, and invasion were detected by MTT, wound healing, and Transwell assays. The binding sites between E2F1 and BMI1 promoters were predicted through JASPAR website, and the targeted binding was verified by dual-luciferase report and ChIP assays.

RESULTS

E2F1 was up-regulated in human EC cell lines, with its expression highest in AN3CA, and lowest in HEC-1. AN3CA invasion, migration, and proliferation were repressed by E2F1 knockdown, while those of HEC-1 cells were promoted by E2F1 overexpression. E2F1 overexpression increased the activity of wild type BMI1 reporter vector promoter, while this promotion was weakened after mutation of the predicted binding site in the BMI1 promoter. In the precipitated E2F1, BMI1 promoter site level was higher than that of IgG immunoprecipitant. BMI1 silencing suppressed AN3CA cell growth. BMI1 overexpression partially abrogated E2F1 silencing-inhibited EC cell growth.

CONCLUSION

E2F1 promoted EC cell proliferation, invasion, and migration by promoting the transcription of BMI1.

Methylation of the transcription factor E2F1 by SETD6 regulates SETD6 expression via a positive feedback mechanism

The protein lysine methyltransferase SET domain-containing protein 6 (SETD6) has been shown to influence different cellular activities and to be critically involved in the regulation of diverse developmental and pathological processes. However, the upstream signals that regulate the mRNA expression of SETD6 are not known. Bioinformatic analysis revealed that the SETD6 promoter has a binding site for the transcription factor E2F1. Using various experimental approaches, we show that E2F1 binds to the SETD6 promoter and regulates SETD6 mRNA expression. Our further observation that this phenomenon is SETD6 dependent suggested that SETD6 and E2F1 are linked. We next demonstrate that SETD6 monomethylates E2F1 specifically at K117 in vitro and in cells. Finally, we show that E2F1 methylation at K117 positively regulates the expression level of SETD6 mRNA. Depletion of SETD6 or overexpression of E2F1 K117R mutant, which cannot be methylated by SETD6, reverses the effect. Taken together, our data provide evidence for a positive feedback mechanism, which regulates the expression of SETD6 by E2F1 in a SETD6 methylation-dependent manner, and highlight the importance of protein lysine methyltransferases and lysine methylation signaling in the regulation of gene transcription.

Thyroid hormone enhances estrogen-mediated proliferation and cell cycle regulatory pathways in steroid receptor-positive breast Cancer

Estrogen receptor (ER) α expression and associated signaling is a major driver of over two-thirds of all breast cancers (BC). ER targeting strategies are typically used as a first-line therapy in patients with steroid receptor positive (SR+) disease. Secondary resistance to anti-estrogenic agents may occur with clonal expansion and disease progression. Mechanisms underlying hormone resistance are an expanding field of significant translational importance. Cross-talk with other nuclear hormones, receptors, and signaling pathways, including thyroid hormones (TH) and their receptors (THRs), have been shown to promote endocrine therapy resistance in some studies. We have shown that TH replacement therapy (THRT) was independently and significantly associated with higher rates of relapse and mortality in SR positive (+), node-negative (LN-) BC patients, whereas it showed no association with outcomes in SR negative (-) patients. LN-, SR+ patients receiving THRT and tamoxifen had the worst outcomes, suggesting a pro-carcinogenic interaction that significantly and independently shortened survival and increased mortality. Using in vivo and in vitro models, we previously showed hormonal cross-talk, altered gene signaling, target gene activation, and resistance to tamoxifen in the presence of TH. In this report, we show TH ± E2 ± tamoxifen inhibits cell cycle control signaling, reduces apoptosis, and enhances cell proliferation, tumor growth, tamoxifen resistance, and clonal expansion. Mechanistically these changes involve numerous genes and pathways, including critical cell cycle regulatory proteins and genes identified using various molecular methods. These studies facilitate a greater mechanistic understanding of the biological and molecular impact of TH on SR+ BC.

PP2A and its adapter protein IER5 induce the DNA-binding ability and target gene expression of E2F1 via dephosphorylation at serine 375

The transcription factor E2F1 participates in cell cycle control through transcriptional activation of genes that promote S-phase entry. E2F1 is also linked to the expression of proapoptotic genes, and the loss of E2F1 activity facilitates tumor progression by reducing cellular apoptosis. Phosphorylation controlled by protein kinases and phosphatases is the major posttranslational modification and regulates the cellular levels and transactivator function of E2F1. Here, we characterize the regulatory roles of serine-375 (S375), one of the major phosphorylation sites of E2F1. Cyclin-dependent kinases such as CDK8 phosphorylate at S375 of E2F1, which is dephosphorylated by protein phosphatase 2A (PP2A) containing the B55 regulatory subunit. The PP2A adapter protein IER5 binds to both PP2A/B55 and E2F1 and assists dephosphorylation at S375 by PP2A. S375-dephosphorylated E2F1 exhibits higher DNA-binding affinity than the phosphorylated form. Although the promoter regions of proapoptotic genes are less occupied by E2F1 in cells, an increase in S375-dephosphorylated E2F1 induces preferential binding of E2F1 to the proapoptotic gene promoters and their expression. Our data identify PP2A/B55-IER5 as a critical regulator of E2F1 and suggest that the phosphorylation state of E2F1 is an important determinant for the expression of proapoptotic genes.

Clinical evidence for a role of E2F1-induced replication stress in modulating tumor mutational burden and immune microenvironment

DNA replication stress (RS) is frequently induced by oncogene activation and is believed to promote tumorigenesis. However, clinical evidence for the role of oncogene-induced RS in tumorigenesis remains scarce, and the mechanisms by which RS promotes cancer development remain incompletely understood. By performing a series of bioinformatic analyses on the oncogene E2F1, other RS-inducing factors, and replication fork processing factors in TCGA cancer database using previously established tools, we show that hyperactivity of E2F1 likely promotes the expression of several of these factors in virtually all types of cancer to induce RS and cytosolic self-DNA production. In addition, the expression of these factors positively correlates with that of ATR and Chk1 that govern the cellular response to RS, the tumor mutational load, and tumor infiltration of immune-suppressive CD4+Th2 cells and myeloid-derived suppressor cells (MDSCs). Consistently, high expression of these factors is associated with poor patient survival. Our study provides new insights into the role of E2F1-induced RS in tumorigenesis and suggests therapeutic approaches for E2F1-overexpressing cancers by targeting genomic instability, cytosolic self-DNA and the tumor immune microenvironment.

GSG2 facilitates the progression of human breast cancer through MDM2-mediated ubiquitination of E2F1

BACKGROUND

Breast cancer (BC) has posed a great threat to world health as the leading cause of cancer death among women. Previous evidence demonstrated that germ cell-specific gene 2 (GSG2) was involved in the regulation of multiple cancers. Thus, the clinical value, biological function and underlying mechanism of GSG2 in BC were investigated in this study.

METHODS

The expression of GSG2 in BC was revealed by immunohistochemistry (IHC), qPCR and western blotting. Secondly, the biological function of GSG2 in BC was evaluated by MTT assay, flow cytometry, Transwell assay and wound healing assay. Furthermore, the potential molecular mechanism of GSG2 regulating the progression of BC by co-immunoprecipitation (Co-IP) and protein stability detection.

RESULTS

Our data indicated that GSG2 was frequently overexpressed in BC. Moreover, there was a significant correlation between the GSG2 expression and the poor prognosis of BC patients. Functionally, GSG2 knockdown inhibited the malignant progression of BC characterized by reduced proliferation, enhanced apoptosis and attenuated tumor growth. Migration inhibition of GSG2 knockdown BC cells via epithelial-mesenchymal transition (EMT), such as downregulation of Vimentin and Snail. In addition, E2F transcription factor 1 (E2F1) was regarded as a target protein of GSG2. Downregulation of E2F1 attenuated the promoting role of GSG2 on BC cells. Mechanistically, knockdown of GSG2 accelerated the ubiquitination of E2F1 protein, which was mediated by E3 ubiquitin ligase MDM2.

CONCLUSIONS

GSG2 facilitated the development and progression of BC through MDM2-mediated ubiquitination of E2F1, which may be a promising candidate target with potential therapeutic value.

HBx promotes hepatocellular carcinoma progression by repressing the transcription level of miR-187-5p

HBV-associated hepatitis B virus x protein (HBx) plays multiple roles in the development of hepatocellular carcinoma. In our prior study, we discovered that miR-187-5p expression was inhibited by HBx. To investigate the underlying molecular mechanism of HBx-mediated miR-187-5p downregulation in hepatocellular carcinoma cells, effects of HBx and miR-187-5p on hepatoma carcinoma cell were observed, as well as their interactions. Through in vitro and in vivo experiments, we demonstrated that overexpression of miR-187-5p inhibited proliferation, migration, and invasion. Simultaneously, we observed a dysregulation in the expression of miR-187-5p in liver cancer cell lines, which may be attributed to transcriptional inhibition through the E2F1/FoxP3 axis. Additionally, we noted that HBx protein is capable of enhancing the expression of E2F1, a transcription factor that promotes the expression of FoxP3. In conclusion, our results suggest that the inhibitory effect of HBx on miR-187-5p is mediated through the E2F1/FoxP3 axis. As shown in this work, HBx promotes hepatoma carcinoma cell proliferation, migration, and invasion through the E2F1/FoxP3/miR-187 axis. It provides a theoretical basis for finding therapeutic targets that will help clinic treatment for HCC.

E2F family play important roles in tumorigenesis

Tumors are serious threats to human health. The transcription factors are regarded as the potential targets for tumor treatment. As an important family of transcription factors, E2F family transcription factors (E2Fs) play vital roles in cell proliferation and regulation. However, the expression feature, gene functions, and molecular interactions of E2Fs in tumorigenesis are not clear. In this study, the transcriptome data, mutation data, and protein-protein interaction data of 10 high-incidence tumors in China from the TCGA database were integrated and analyzed to explore the expression, structure, function, mutation, and phylogenetic characteristics of E2Fs. The results showed that E2F1 and E2F7 were regularly upregulated in the tumor samples. Moreover, E2Fs participated in the regulation of the cell cycle, cell aging, and other signaling pathways. As an important regulator, E2F1 interacted with more proteins than other E2Fs. At the same time, the genetic mutation types of E2Fs varied in tumor type and patient sex, of which gene amplification accounts for the largest proportion. Phylogenetic analysis showed that E2Fs were conserved in 41 species, including fruit flies, nematodes, and humans. Meanwhile, E2Fs had a tendency for gene expansion during evolution. In conclusion, this study clarified the expression pattern, mutation characteristics, and evolutionary trend of E2Fs in high-incidence tumors in China, and suggested that E2F family transcription factors could be novel diagnostic markers for tumor diseases. Furthermore, this work can provide a theoretical basis for the development of anti-tumor-targeted drugs.

SENP5 deteriorates traumatic brain injury via SUMO2-dependent suppression of E2F1 SUMOylation

Traumatic brain injury (TBI) represents a main public health concern during the past decade, attracting considerable interest because of its rising prevalence, wide-ranging risk factors and lifelong familial and societal influence. SUMO2 can conjugate to substrates upon various cellular stresses. Nevertheless, whether and how SUMO2-specific proteases partake in TBI is less understood. The aim of this study is to dissect the effects of SUMO-specific peptidase 5 (SENP5) on accentuating TBI in rats in an effort to unveil its underlying mechanism. SENP5 is overexpressed in hippocampal tissues of TBI rats, and inhibition of SENP5 reduces neurological function scores, decreases brain water content, inhibits apoptosis in hippocampal tissues, and attenuates brain injury caused in rats. Moreover, SENP5 inhibits the SUMOylation level of E2F transcription factor 1 (E2F1) and increases the protein expression of E2F1. Silencing of E2F1 blocks the p53 signaling pathway. Overexpression of E2F1 partially reverses the protective effect of sh-SENP5 on TBI in rats. These findings reveal an essential role of SENP5 and the SUMOylation status of E2F1 in the TBI development.

The E2F1/MELTF axis fosters the progression of lung adenocarcinoma by regulating the Notch signaling pathway

BACKGROUND

Lung adenocarcinoma (LUAD) represents the predominant subtype of lung cancer. MELTF, an oncogene, exhibits high expression in various cancer tissues. Nevertheless, the precise role of MELTF in the progression of LUAD remains enigmatic. This work was devised to investigate the effect of MELTF on LUAD progression and its underlying mechanism.

METHODS

mRNA expression data of LUAD were from The Cancer Genome Atlas database, and the enrichment pathway of MELTF was analyzed. The upstream transcription factors of MELTF were predicted, and the correlation between MELTF and E2F1 as well as the expression of the two in LUAD tissues were dissected by bioinformatics. The expression of MELTF and E2F1 in LUAD tissues and cells was assayed by qRT-PCR. Effects of MELTF/E2F1 on proliferation, migration, and invasion of LUAD cells were tested by CCK-8, colony formation, and Transwell assays. The binding relationship between E2F1 and MELTF was estimated by dual-luciferase reporter gene assay and ChIP assay. Western blot was utilized to assay the expression of Notch signaling pathway-related proteins in different treatment groups.

RESULTS

Bioinformatics analysis and qRT-PCR results exhibited high expression of E2F1 and MELTF in LUAD tissues and cells, respectively. Dual-luciferase reporter gene assay and ChIP assay ascertained the binding of E2F1 to MELTF. MELTF was ascertained to enrich the Notch signaling pathway by bioinformatics means. In cell experiments, MELTF was shown to foster the malignant progression of LUAD cells and promoted the expression of NOTCH1 and HES1 proteins, but RO4929097 offset the effect of MELTF on cells. Rescue assay confirmed that E2F1 activated MELTF to promote LUAD progression via the Notch signaling pathway.

CONCLUSION

Together, our outcomes demonstrated that E2F1 fostered LUAD progression by activating MELTF via the Notch signaling activity. Hence, MELTF emerged as a feasible target for treating LUAD.

PRB inhibited cell proliferation through let-7b-E2F1 in breast cancer

The presence of progesterone receptor (PR) and PR isoform B (PRB) in breast cancer is generally correlated with better clinical outcomes. Additionally, the significance of hormone-independent effects of PR/PRB correlated with better prognosis has been reported in non-small cell lung cancer (NSCLC). However, the detailed mechanism of that still remains unclear. In this study, we examined how microRNAs (miRNAs) could contribute to tumor inhibition via PR/PRB expression, in order to find miRNAs that have tumor-agnostic effects between breast cancer and NSCLC. We obtained miRNA data using human tissues of breast cancer and NSCLC from The Cancer Genome Atlas (TCGA) database and PCR array from NSCLC patients of our cohort. Subsequently, we examined the function of the miRNA through in vitro study using breast cancer cell lines. As a result, only let-7b expression was significantly correlated with PR expression in both cancers. Additionally, the expression of let-7b significantly inhibited cell proliferation by inducing PR and PRB expression in breast cancer cell lines. However, the positive correlation of let-7b and PRB required a mediated factor, E2 promoter binding factor 1 (E2F1), obtained from TCGA database analysis. In vitro experiments showed that let-7b significantly inhibited E2F1, and E2F1 significantly inhibited PRB. This study revealed that PRB inhibits the proliferation of breast cancer cells by the let-7b-E2F1 interaction. In addition, the immunohistochemical analysis in NSCLC was also consistent with these in vitro data. Our results could contribute to developing novel therapeutic strategies for patients with PR/PRB-positive cancer by targeting let-7b or PRB expression in breast cancer and possibly NSCLC.

Prognostic role of E2F1 gene expression in human cancer: a meta-analysis

OBJECTIVE

E2F1 has been confirmed to be highly expressed in a variety of cancers. To better understand the prognostic value of E2F1 in cancer patients, this study was conducted to comprehensively evaluate the prognostic value of E2F1 in cancer according to published data.

METHOD

PubMed, Web of Science and CNKI database were searched until May 31^th, 2022 by using key words to retrieve the published essays on the role of E2F1 expression in the prognostic value of cancer. The essays were identified according to the inclusion and exclusion criteria. The pooled result of hazard ratio and 95% confidence interval was calculated with Stata17.0 software.

RESULT

A total of 17 articles were included in this study involved in 4481 cancer patients. The pooled results showed that higher E2F1 expression was significantly correlated with unfavorable overall survival (HR = 1.10, I² = 95.3%, *P_{Heterogeneity} = 0.000) and disease-free survival (HR = 1.41, I² = 95.2%, *P_{Heterogeneity} = 0.000) of cancer patients. Such a significant association of was maintained subgroup of sample size of patients (> 150: for OS, HR = 1.77, and for DFS, HR = 0.91; or < 150: for OS, HR = 1.93, and for DFS, HR = 4.39), ethnicity (Asian: for OS, HR = 1.65, and for DFS, HR = 1.08; or not Asian: HR = 3.55, and for DFS, HR = 2.87), the data from database (clinical: for OS, HR = 1.24, and for DFS, HR = 1.40; or database: for OS, HR = 2.29, and for DFS, HR = 3.09), paper published year (after 2014: for OS, HR = 1.90;and for DFS,HR = 1.87; or before 2014: for OS, HR = 1.40, and for DFS, HR = 1.22); cancer type (female specific cancer: for OS, HR = 1.41, and for DFS, HR = 0.64; or non-gender specific cancers: for OS, HR = 2.00, and for DFS, HR = 2.95). In addition, according to the database data, we also found that higher E2F1 expression level would lead to worse prognosis of patients, and the results were consistent with the statistical analysis results in the paper.

CONCLUSION

E2F1 could be served as a prognostic biomarker in cancer patients and higher levels of in cancer patients could predict shorter overall survival and disease-free survival.

The E2F1-HOXB9/PBX2-CDK6 axis drives gastric tumorigenesis and serves as a therapeutic target in gastric cancer

Homeobox genes include HOX and non-HOX genes. HOX proteins play fundamental roles during ontogenesis by interacting with other non-HOX gene-encoded partners and performing transcriptional functions, whereas aberrant activation of HOX family members drives tumorigenesis. In this study, gastric cancer (GC) expression microarray data indicated that HOXB9 is a prominent upregulated HOX member in GC samples significantly associated with clinical outcomes and advanced TNM stages. However, the functional role of HOXB9 in GC remains contradictory in previous reports, and the regulatory mechanisms are elusive. By in silico and experimental analyses, we found that HOXB9 was upregulated by a vital cell cycle-related transcription factor, E2F1. Depleting HOXB9 causes G1-phase cell cycle arrest by downregulating CDK6 and a subset of cell cycle-related genes. Meanwhile, HOXB9 contributes to cell division and maintains the cytoskeleton in GC cells. We verified that HOXB9 interacts with PBX2 to form a heterodimer, which transcriptionally upregulates CDK6. Knocking down CDK6 can phenocopy the tumor-suppressive effects caused by HOXB9 depletion. Blocking HOXB9 can enhance the anti-tumor effect of CDK6 inhibitors. In conclusion, we elucidate the oncogenic role of HOXB9 in GC and reveal CDK6 as its potent downstream effector. The E2F1-HOXB9/PBX2-CDK6 axis represents a novel mechanism driving gastric carcinogenesis and conveys prognostic and therapeutic implications. © 2023 The Pathological Society of Great Britain and Ireland.

Identification of the E2F1-RAD51AP1 axis as a key factor in MGMT-methylated GBM TMZ resistance

OBJECTIVE

Epidermal growth factor receptor variant III (EGFRvIII) is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme (GBM). Temozolomide (TMZ) is a standard chemotherapeutic for GBM, but TMZ treatment benefits are compromised by chemoresistance. This study aimed to elucidate the crucial mechanisms leading to EGFRvIII and TMZ resistance.

METHODS

CRISPR-Cas13a single-cell RNA-seq was performed to thoroughly mine EGFRvIII function in GBM. Western blot, real-time PCR, flow cytometry, and immunofluorescence were used to determine the chemoresistance role of E2F1 and RAD51-associated protein 1 (RAD51AP1).

RESULTS

Bioinformatic analysis identified E2F1 as the key transcription factor in EGFRvIII-positive living cells. Bulk RNA-seq analysis revealed that E2F1 is a crucial transcription factor under TMZ treatment. Western blot suggested enhanced expression of E2F1 in EGFRvIII-positive and TMZ-treated glioma cells. Knockdown of E2F1 increased sensitivity to TMZ. Venn diagram profiling showed that RAD51AP1 is positively correlated with E2F1, mediates TMZ resistance, and has a potential E2F1 binding site on the promoter. Knockdown of RAD51AP1 enhanced the sensitivity of TMZ; however, overexpression of RAD51AP1 was not sufficient to cause chemotherapy resistance in glioma cells. Furthermore, RAD51AP1 did not impact TMZ sensitivity in GBM cells with high O⁶-methylguanine-DNA methyltransferase (MGMT) expression. The level of RAD51AP1 expression correlated with the survival rate in MGMT-methylated, but not MGMT-unmethylated TMZ-treated GBM patients.

CONCLUSIONS

Our results suggest that E2F1 is a key transcription factor in EGFRvIII-positive glioma cells and quickly responds to TMZ treatment. RAD51AP1 was shown to be upregulated by E2F1 for DNA double strand break repair. Targeting RAD51AP1 could facilitate achieving an ideal therapeutic effect in MGMT-methylated GBM cells.

Prognostic stratification of endometrial cancers with high microsatellite instability or no specific molecular profile

Objective

To identify high-risk disease in clinicopathologic low-risk endometrial cancer (EC) with high microsatellite instability (MSI-H) or no specific molecular profile (NSMP) and therapeutic insensitivity in clinicopathologic high-risk MSI-H/NSMP EC.

Methods

We searched The Cancer Genome Atlas for DNA sequencing, RNA expression, and surveillance data regarding MSI-H/NSMP EC. We used a molecular classification system of E2F1 and CCNA2 expression and sequence variations in POLE, PPP2R1A, or FBXW7 (ECPPF) to prognostically stratify MSI-H/NSMP ECs. Clinical outcomes were annotated after integrating ECPPF and sequence variations in homologous recombination (HR) genes.

Results

Data were available for 239 patients with EC, which included 58 MSI-H and 89 NSMP cases. ECPPF effectively stratified MSI-H/NSMP EC into distinct molecular groups with prognostic implications: molecular low risk (MLR), with low CCNA2 and E2F1 expression, and molecular high risk (MHR), with high CCNA2 and E2F1 expression and/or PPP2R1A and/or FBXW7 variants. The 3-year disease-free survival (DFS) rate was 43.8% in the MHR group with clinicopathologic low-risk indicators and 93.9% in the MLR group (P<.001). In the MHR group, wild-type HR genes were present in 28% of cases but in 81% of documented recurrences. The 3-year DFS rate in patients with MSI-H/NSMP EC with clinicopathologic high-risk indicators was significantly higher in the MLR (94.1%) and MHR/HR variant gene (88.9%) groups than in the MHR/HR wild-type gene group (50.3%, P<.001).

Conclusion

ECPPF may resolve prognostic challenges for MSI-H/NSMP EC by identifying occult high-risk disease in EC with clinicopathologic low-risk indicators and therapeutic insensitivity in EC with clinicopathologic high-risk indicators.

Normal cell cycle progression requires negative regulation of E2F1 by Groucho during S-phase and its relief at G2-phase

The cell cycle depends on a sequence of steps that are triggered and terminated via the synthesis and degradation of phase-specific transcripts and proteins. While much is known about how stage-specific transcription is activated, less is understood about how inappropriate gene expression is suppressed. In this paper we demonstrate that Groucho, the Drosophila orthologue of TLE1 and other related human transcriptional corepressors, regulates normal cell cycle progression in vivo. We show that although Groucho is expressed throughout the cell cycle, its activity is selectively inactivated by phosphorylation, except in S-phase when it negatively regulates E2F1. Constitutive Groucho activity, as well as its depletion and the consequent derepression of e2f1, cause cell cycle phenotypes. Our results suggest that Cdk1 contributes to phase-specific phosphorylation of Groucho in vivo. We propose that Groucho and its orthologues play a role in the metazoan cell cycle that may explain the links between TLE corepressors and several types of human cancer.

ANKRD22 promotes glioma proliferation, migration, invasion, and epithelial-mesenchymal transition by upregulating E2F1-mediated MELK expression

Ankyrin repeat domain protein 22 (ANKRD22) has been implicated in various types of cancers but its expression and potential functions have not been investigated in gliomas. In this study, the high expression of ANKRD22 in gliomas and its correlation with survival were identified based on the Cancer Genome Atlas database. Similar expression trends were observed in glioma tissues and cell lines. Functionally, the loss of ANKRD22 suppressed glioma cell proliferation, migration, and invasion and cell cycle progression in vitro and tumor growth in vivo. Mechanistically, ANKRD22 interacted with the E2F transcription factor 1 (E2F1), thereby upregulating maternal embryonic leucine zipper kinase (MELK) protein expression. Moreover, E2F1 overexpression partly restored ANKRD22 silence-mediated tumor suppressive effects in glioma cells. In conclusion, our data highlight the oncogenic role of ANKRD22 in gliomas via E2F1/MELK signaling, which may serve as a promising target for glioma treatment.

Silencing of RAB42 down-regulated PD-L1 expression to inhibit the immune escape of hepatocellular carcinoma cells through inhibiting the E2F signaling pathway

OBJECTIVE

To investigate the mechanistic role of RAB42 and corresponding regulatory path in hepatocellular carcinoma (HCC).

METHODS

The expression of RAB42 in HCC tissue was checked by RT-qPCR and immunohistochemical staining assay. Cell proliferation was checked by colony formation and CCK-8 assay. Cell apoptosis and cycle distribution were analyzed with flow cytometry. The relevance of RAB42 and PD-L1 was analyzed from TCGA database. The binding of E2F1 to PD-L1 was detected by JASPAR database, luciferase and ChIP assay. The expression of PD-L1, cell apoptosis- and E2F pathway-related proteins were checked by western blotting.

RESULTS

RAB42 was highly expressed in HCC tissue. RAB42 silencing could inhibit proliferation and induce G1 phase arrest and apoptosis of HCC cells. TCGA database disclosed that PD-L1 was highly associated with RAB42 expression. Silencing of RAB42 could retard PD-L1 expression in HCC cells. GSEA analysis showed RAB42 could activate E2F signaling pathway. Silencing of RAB42 could observably weaken the expression of E2F1, CDK1 and CDC20 in HCC cells. JASPAR database predicted the binding site between E2F1 and PD-L1, and E2F1 overexpression could promote PD-L1 expression. Overexpression of E2F1 could reverse the biological function of RAB42 silencing in HCC cells.

CONCLUSION

Silencing of RAB42 could down-regulate PD-L1 expression to inhibit immune escape through inhibiting E2F signaling pathway in HCC cells. RAB42 may become a novel clinical diagnostic and therapy marker for HCC.

E2F1-mediated ectopic expression of PP1A promotes breast cancer progression via activation of YAP1

Hormone receptor-positive breast cancer is the most common subtype of breast cancer. The protein phosphatase PP1A gene is described as an oncogene in several tumor types; however, the biological function of PP1A in hormone receptor-positive breast cancer remains unclear. The Cancer Genome Atlas data indicates PP1A expression is upregulated in hormone receptor-positive breast cancer tissues than in normal breast tissues. We explored the biological function of PP1A in hormone receptor-positive breast cancer using MTT assays, colony formation assays, and a xenograft mouse model. The results indicated that PP1A promoted hormone receptor-positive breast cancer proliferation, both in vitro and in vivo. Mechanistically, LINC02754 recruited the binding of the transcription factor E2F1 to the PP1A promotor, thereby increasing PP1A expression. The PP1A then interacted with and dephosphorylated YAP1, resulting in YAP1 activation. The dephosphorylated YAP1 moved to the nucleus and increased the expression of the downstream oncogene CTGF, promoting hormone receptor-positive breast cancer progression. Our findings reveal the function of the LINC02754/E2F1/PP1A/YAP1 axis in hormone receptor-positive breast cancer and provide new insight into hormone receptor-positive breast cancer progression.

The SARS-CoV-2 spike S1 protein induces global proteomic changes in ATII-like rat L2 cells that are attenuated by hyaluronan

The COVID-19 pandemic continues to impose a major impact on global health and economy since its identification in early 2020, causing significant morbidity and mortality worldwide. Caused by the SARS-CoV-2 virus, along with a growing number of variants, COVID-19 has led to 651,918,402 confirmed cases and 6,656,601 deaths worldwide (as of December 27, 2022; https://covid19.who.int/). Despite advances in our understanding of COVID-19 pathogenesis, the precise mechanism by which SARS-CoV2 causes epithelial injury is incompletely understood. In this current study, robust application of global-discovery proteomics identified highly significant induced changes by the Spike S1 protein of SARS-CoV-2 in the proteome of alveolar type II (ATII)-like rat L2 cells that lack ACE2 receptors. Systems biology analysis revealed that the S1-induced proteomics changes were associated with three significant network hubs: E2F1, CREB1/RelA, and ROCK2/RhoA. We also found that pretreatment of L2 cells with high molecular weight hyaluronan (HMW-HA) greatly attenuated the S1 effects on the proteome. Western blotting analysis and cell cycle measurements confirmed the S1 upregulation of E2F1 and ROCK2/RhoA in L2 cells and the protective effects of HMW-HA. Taken as a whole, our studies revealed profound and novel biological changes that contribute to our current understanding of both S1 and hyaluronan biology. These data show that the S1 protein may contribute to epithelial injury induced by SARS-CoV-2. In addition, our work supports the potential benefit of HMW-HA in ameliorating SARS CoV-2-induced cell injury.

Adaptations in Nucleus Accumbens Neuron Subtypes Mediate Negative Affective Behaviors in Fentanyl Abstinence

BACKGROUND

Opioid discontinuation generates a withdrawal syndrome marked by increased negative affect. Increased symptoms of anxiety and dysphoria during opioid discontinuation are significant barriers to achieving long-term abstinence in opioid-dependent individuals. While adaptations in the nucleus accumbens are implicated in opioid abstinence syndrome, the precise neural mechanisms are poorly understood. Additionally, our current knowledge is limited to changes following natural and semisynthetic opioids, despite recent increases in synthetic opioid use and overdose.

METHODS

We used a combination of cell subtype-specific viral labeling and electrophysiology in male and female mice to investigate structural and functional plasticity in nucleus accumbens medium spiny neuron (MSN) subtypes after fentanyl abstinence. We characterized molecular adaptations after fentanyl abstinence with subtype-specific RNA sequencing and weighted gene co-expression network analysis. We used viral-mediated gene transfer to manipulate the molecular signature of fentanyl abstinence in D1-MSNs.

RESULTS

Here, we show that fentanyl abstinence increases anxiety-like behavior, decreases social interaction, and engenders MSN subtype-specific plasticity in both sexes. D1-MSNs, but not D2-MSNs, exhibit dendritic atrophy and an increase in excitatory drive. We identified a cluster of coexpressed dendritic morphology genes downregulated selectively in D1-MSNs that are transcriptionally coregulated by E2F1. E2f1 expression in D1-MSNs protects against loss of dendritic complexity, altered physiology, and negative affect-like behaviors caused by fentanyl abstinence.

CONCLUSIONS

Our findings indicate that fentanyl abstinence causes unique structural, functional, and molecular changes in nucleus accumbens D1-MSNs that can be targeted to alleviate negative affective symptoms during abstinence.

SNHG15 enhances cisplatin resistance in lung adenocarcinoma by affecting the DNA repair capacity of cancer cells

BACKGROUND

Lung adenocarcinoma (LUAD) is a prevalent malignancy. SNHG15 has been demonstrated to be oncogenic in many kinds of cancers, however the mechanism of SNHG15 in LUAD cisplatin (DDP) resistance remains unclear. In this study, we demonstrated the effect of SNHG15 on DDP resistance in LUAD and its related mechanism.

METHODS

Bioinformatics analysis was adopted to assess SNHG15 expression in LUAD tissues and predict the downstream genes of SNHG15. The binding relationship between SNHG15 and downstream regulatory genes was proved through RNA immunoprecipitation, chromatin immunoprecipitation and dual-luciferase reporter assays. Cell counting kit-8 assay was adopted to evaluate LUAD cell viability, and gene expression was determined by Western blot and quantitative real-time polymerase chain reaction. We then performed comet assay to assess DNA damage. Cell apoptosis was detected by Tunnel assay. Xenograft animal models were created to test the function of SNHG15 in vivo.

RESULTS

SNHG15 was up-regulated in LUAD cells. Moreover, SNHG15 was also highly expressed in drug-resistant LUAD cells. Down-regulated SNHG15 strengthened the sensitivity of LUAD cells to DDP and induced DNA damage. SNHG15 could elevate ECE2 expression through binding with E2F1, and it could induce DDP resistance by modulating the E2F1/ECE2 axis. In vivo experiments verified that the SNHG15 could enhance DDP resistance in LUAD tissue.

CONCLUSION

The results suggested that SNHG15 could up-regulate ECE2 expression by recruiting E2F1, thereby enhancing the DDP resistance of LUAD.

Circ_0001982 Up-regulates the Expression of E2F1 by Adsorbing miR-1205 to Facilitate the Progression of Glioma

This study was aimed at probing into the regulatory effects of circular RNA (circRNA)_0001982 on glioma cell proliferation, migration, invasion, and cell cycle, and its underlying mechanism. CircRNA expression profile of glioma tissues/normal brain tissues was downloaded from the Gene Expression Omnibus (GEO) database and analyzed. Circ_0001982, microRNA (miRNA, miR)-1205, and E2F transcription factor 1 (E2F1) expressions in glioma tissues and cell lines were quantified using quantitative real-time polymerase chain reaction (qRT-PCR) and/or Western blot. Glioma cell proliferation, migration, invasion, and cell cycle were detected employing cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), scratch-healing, Transwell, and flow cytometry assays, respectively. The targeting relationships between miR-1205 and circ_0001982, and miR-1205 and E2F1 3'UTR were verified using bioinformatics, dual-luciferase reporter experiments, and RNA immunoprecipitation (RIP) assay. Pearson's correlation analysis was applied to detect the correlations among circ_0001982, miR-1205, and E2F1 expression levels. Circ_0001982 expression level was increased in glioma tissues and correlated with larger tumor size. Circ_0001982 overexpression enhanced glioma cell proliferation, migration, and invasion, and accelerated cell cycle progression while knocking down circ_0001982 exerted opposite effects. Circ_0001982 directly targeted miR-1205, and miR-1205 directly targeted E2F1. Besides, circ_0001982 could up-regulate E2F1 expression via repressing miR-1205 expression. Circ_0001982 accelerates glioma progression by modulating the miR-1205/E2F1 axis.

hMSH2 coordinated with the expression of E2F1 promotes platinum response in epithelial ovarian cancer

OBJECTIVE

To explore underlying mechanisms that regulate hMSH2 expression and drug susceptibility in epithelial ovarian cancer (EOC).

METHODS

Using data from the Cancer Genome Atlas (TCGA) we used bioinformatical analysis to predict transcription factors (TFs) that potentially regulate hMSH2. RT-qPCR, Western blot, and luciferase assays were undertaken using ovarian cancer cell lines to verify the identified TF. Expressions of the TF were modulated using overexpression or knockdown, and the corresponding cellular responses to cisplatin were examined.

RESULTS

The TF, E2F1, was found to regulate the hMSH2 gene. The expression level of E2F1 correlated with cisplatin susceptibility in vitro. Kaplan-Meier analysis of 77 patients with EOC showed that low E2F1 expression was associated with worse survival.

CONCLUSIONS

To our knowledge, this is the first report of E2F1 regulated MSH2 expression playing a role in drug resistance of platinum-based treatments for patients with EOC. Further work is need to confirm our results.

PLAGL2 promotes the stemness and is upregulated by transcription factor E2F1 in human lung cancer

This study mainly focuses on revealing the role of PLAGL2 in lung cancer stemness. In vitro and in vivo experiments were performed to evaluate the effects of PLAGL2 on lung cancer cell stemness. Mechanistic analysis using luciferase reporter and ChIP assays were implemented to reveal the underlying mechanisms. The transcriptional factor E2F1 transcriptionally activated PLAGL2 expression via directly binding to PLAGL2 promoter in lung cancer cells. Moreover, PLAGL2 promoted the stemness of lung cancer cells dependent on E2F1-mediated transcriptional activation. This study provides a potential target for lung cancer progression.

LncRNA LIMp27 Regulates the DNA Damage Response through p27 in p53-Defective Cancer Cells

P53 inactivation occurs in about 50% of human cancers, where p53-driven p21 activity is devoid and p27 becomes essential for the establishment of the G1/S checkpoint upon DNA damage. Here, this work shows that the E2F1-responsive lncRNA LIMp27 selectively represses p27 expression and contributes to proliferation, tumorigenicity, and treatment resistance in p53-defective colon adenocarcinoma (COAD) cells. LIMp27 competes with p27 mRNA for binding to cytoplasmically localized hnRNA0, which otherwise stabilizes p27 mRNA leading to cell cycle arrest at the G0/G1 phase. In response to DNA damage, LIMp27 is upregulated in both wild-type and p53-mutant COAD cells, whereas cytoplasmic hnRNPA0 is only increased in p53-mutant COAD cells due to translocation from the nucleus. Moreover, high LIMp27 expression is associated with poor survival of p53-mutant but not wild-type p53 COAD patients. These results uncover an lncRNA mechanism that promotes p53-defective cancer pathogenesis and suggest that LIMp27 may constitute a target for the treatment of such cancers.

A Simple, Test-Based Method to Control the Overestimation Bias in the Analysis of Potential Prognostic Tumour Markers

The early evaluation of prognostic tumour markers is commonly performed by comparing the survival of two groups of patients identified on the basis of a cut-off value. The corresponding hazard ratio (HR) is usually estimated, representing a measure of the relative risk between patients with marker values above and below the cut-off. A posteriori methods identifying an optimal cut-off are appropriate when the functional form of the relation between the marker distribution and patient survival is unknown, but they are prone to an overestimation bias. In the presence of a small sample size, which is typical of rare diseases, the external validation sets are hardly available and internal cross-validation could be unfeasible. We describe a new method to obtain an unbiased estimate of the HR at an optimal cut-off, exploiting the simple relation between the HR and the associated p-value estimated by a random permutation analysis. We validate the method on both simulated data and set of gene expression profiles from two large, publicly available data sets. Furthermore, a reanalysis of a previously published study, which included 134 Stage 4S neuroblastoma patients, allowed for the identification of E2F1 as a new gene with potential oncogenic activity. This finding was confirmed by an immunofluorescence analysis on an independent cohort.

Knockout of ICAT in Adipose Tissue Alleviates Fibro-inflammation in Obese Mice

The E2 promoter binding factor 1 (E2F1) and the Wnt/β-catenin signaling are crucial in regulating metabolic homeostasis including obesity. The β-catenin interacting protein 1 (CTNNBIP1), also known as the inhibitor of β-catenin and TCF4 (ICAT), is required for E2F1 to inhibit the activity of β-catenin. However, the role of ICAT in E2F1 regulating obesity-related metabolic disorders remains unknown. In the present study, male adipose tissue-specific ICAT knockout (ICAT^adi-/-) C57BL/6 J mice and control littermates aged 6-8 weeks were fed with high-fat diet (HFD) for 12 weeks to explore the effect of ICAT on lipid metabolism and obesity-related disorders. Results showed that the adipose tissue-specific ICAT knockout had negligible effect on lipid metabolism, reflected by no difference in body weight, fat mass, and the expression of proteins involved in lipid metabolism in white adipose tissue (WAT) and the liver between the ICAT^adi-/- mice and the control littermate (ICAT^fl/fl) mice. However, the knockout of ICAT reduced inflammatory response in WAT and the liver. Additionally, Sirius red staining results showed that deletion of ICAT attenuated fibrosis and reduced mRNA levels of transforming growth factor β1(TGF-β1), matrix metallopeptidase 2 (Mmp2), Mmp3, and collagen, type V, alpha 1 (Col5a1) in WAT and the liver. These results suggested that knockout of ICAT improved the metabolic abnormalities of obese mice through attenuating adipose tissue and the liver inflammation as well as fibrosis. Our findings may provide a new insight to understand the role of ICAT in inflammation and fibrosis.

SNHG3 regulates NEIL3 via transcription factor E2F1 to mediate malignant proliferation of hepatocellular carcinoma

The involvement of small nucleolar RNA host gene 3 (SNHG3) in cancer regulation has been reported. This study attempted to deeply investigate the molecular regulatory mechanism of SNHG3 on malignant progression of hepatocellular carcinoma (HCC). According to TCGA analysis, high SNHG3 expression was a risk factor for poor prognosis of HCC patients. Therefore, we further detected the mRNA level of SNHG3 in HCC tissue and cells. It was found that SNHG3 was upregulated in HCC tissue and cells. Afterwards, CCK-8 and flow cytometry assays further proved that silencing SNHG3 inhibited HCC cell proliferation while inducing cell apoptosis and G0/G1 phase arrest. It was also attested in vivo experiments that silencing SNHG3 could reduce the volume and weight of tumors and downregulate the Ki-67 expression to suppress HCC tumor growth. Next, it was discovered that SNHG3 increased the binding of E2F1 and NEIL3 promoter region, thereby activating the transcription feature of NEIL3. Lastly, rescue assays indicated that NEIL3 participated in SNHG3-mediated HCC cell cycle, apoptosis and proliferation. All in all, this study revealed the specific regulatory mechanism of SNHG3 in HCC to enable SNHG3 a hopeful marker for HCC diagnosis and treatment.

E2F1 combined with LINC01004 super-enhancer to promote hepatocellular carcinoma cell proliferation and metastasis

INTRODUCTION

Super-enhancer-associated lncRNAs play important roles in the occurrence and development of malignant tumors, including hepatocellular carcinoma (HCC).

OBJECTIVES

The current work aimed to identify and characterize super-enhancer-associated lncRNAs in the pathogenesis of HCC.

METHODS

H3K27ac ChIP-seq data from HepG2 cell line and two HCC tissues were used to identify super-enhancer-associated lncRNAs in HCC. JQ-1 treatment and CRISPR-dCas9 system were performed to confirm super-enhancer activity. Quantitative real-time PCR (qPCR), ChIP-qPCR, and dual-luciferase reporter system assay demonstrated the regulation of E2F1 on super-enhancer. Functional loss experiment was used to identify the function of LINC01004.

RESULTS

In this study, we identified and characterized LINC01004, a novel super-enhancer-associated lncRNA, as a crucial oncogene in HCC. LINC01004 was upregulated in liver cancer tissues and was associated with poor patient prognosis. Moreover, LINC01004 promoted cell proliferation and metastasis of HCC. The binding of E2F1 to the super-enhancer could promote the transcription of LINC01004, while the inhibition of super-enhancer activity decreased LINC01004 expression.

CONCLUSION

This finding might provide mechanistic insights into the molecular mechanisms underlying hepatocarcinogenesis and the biological function of super-enhancer. LINC01004 can serve as a potential therapeutic target for HCC patient.