E2F Transcription Factor Research Articles

E2F8 facilitates malignant phenotypes of muscle-invasive bladder cancer via increasing MCM7 expression.

E2F transcription factor 8 (E2F8) is an important regulator of the cell cycle. In this study, we first assessed the expression of E2F8 in bladder cancer and examined its effects in the malignant phenotypes of bladder cancer cell lines. We found that E2F8 was upregulated in bladder cancer tissues, and the increased expression was positively associated with higher clinical stage. E2F8 knockdown suppressed bladder cancer cell proliferation, accompanied by the performance of G1 phase arrest and the upregulated Cyclin D1 protein expression. The migrative and invasive capability was reduced in E2F8-depleted bladder cancer cells. Cisplatin resistance is an important cause of bladder cancer relapse. E2F8 downregulation facilitated cisplatin-induced apoptosis of bladder cancer cells. MCM7 is regulated by E2F and has been shown to participate in bladder cancer. There was a positive correlation between E2F8 and MCM7 expression in bladder cancer. We confirmed that E2F8 bound to the promoter region of MCM7 and activated MCM7 transcription. MCM7 overexpression abrogated the suppressive effects of E2F8 knockdown on malignant phenotypes of bladder cancer cells. We also demonstrated that E2F8 knockdown suppressed bladder cancer progression in vivo. In conclusion, we verify that E2F8 functioned in bladder cancer, and might exert its function via MCM7.

E2F1 Promotes the Occurrence of Head and Neck Squamous Cell Carcinoma and Serves as a Prognostic Biomarker.

Head and neck squamous cell carcinoma (HNSCC) is a common malignant tumor occurring in various sites such as the oral cavity, pharynx, larynx, and nasal cavity. This study aimed to explore the biological functions and prognostic value of E2F transcription factor 1 (E2F1) in HNSCC. Transcriptome and single-cell sequencing (scRNA-seq) data of HNSCC patients were analyzed using data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO). All samples were divided into high and low expression groups based on the expression levels of E2F1. A risk model was constructed based on Lasso-Cox regression, and the differences between the two groups in terms of prognosis were explored. The scRNA-seq data of HNSCC samples were analyzed using the Seurat package to identify cell types. AUCell was used to score different types of cells, and subsequently, the interaction pathways between the high-scoring cell population and other cell populations were explored using the CellChat package. The expression level of E2F1 in tumor tissues was higher than that in normal tissues, which was confirmed by in vitro experiments. Analysis of transcriptome data from TCGA revealed significant differences in overall survival (OS) between the high and low expression groups. Prognostic genes were selected based on DEGs between the two groups, and a risk model was constructed. Subsequently, a nomogram model was constructed based on clinical factors and risk scores, which exhibited good predictive performance. The expression landscape of prognostic genes in different cell types was explored using scRNA-seq data of HNSCC samples. Dendritic cell populations were identified as high-scoring cell populations, and the pathways of interaction between this cell population and other cell populations were explored. We identified E2F1 as an independent prognostic factor closely associated with the prognosis and immune response of HNSCC.

DTL promotes the growth and migration of melanoma cells through the ERK/E2F1/BUB1 axis

Melanoma is the most dangerous form of skin cancer. Hence, a better understanding of molecular mechanisms in melanoma pathogenesis is urgently needed, which provides a new insight into the therapy of melanoma. DTL gene is screened out in melanoma pathogenesis by integrated bioinformatics analysis, and its expression is validated in the tissue and cell samples of melanoma. Forced DTL expression facilitates the proliferation, invasion, migration and EMT of melanoma cells, while DTL knockdown suppresses the biological behavior of melanoma cells. In addition, DTL promotes the malignancy of melanoma in vivo. Mechanistically, BUB1 is the crucial downstream target of DTL. Reduced DTL expression suppresses BUB1 expression, while enhanced DTL expression induces BUB1 upregulation. Rescue experiments showed that growing and migrating of melanoma cells induced by DTL are partially impaired by BUB1 inhibition. In addition, the expression of phosphorylated ERK (p-ERK) and the downstream transcription factor E2F1 are reduced when DTL expression is blocked. Meanwhile, BUB1 levels are decreased when the expression of p-ERK or E2F1 is repressed. Notably, the growth and migration of melanoma cells by inhibition of ERK and knockdown of E2F1 was rescued by overexpressing BUB1. DTL gene may be a prognosis marker and represent a unique potential target for melanoma patients. DTL supports the biologically malignant activity of melanoma cells via the ERK/E2F1/BUB1 axis.

E2F1-induced autocrine IL-6 inflammatory loop mediates cancer-immune crosstalk that predicts T cell phenotype switching and therapeutic responsiveness.

Melanoma is a metastatic, drug-refractory cancer with the ability to evade immunosurveillance. Cancer immune evasion involves interaction between tumor intrinsic properties and the microenvironment. The transcription factor E2F1 is a key driver of tumor evolution and metastasis. To explore E2F1's role in immune regulation in presence of aggressive melanoma cells, we established a coculture system and utilized transcriptome and cytokine arrays combined with bioinformatics and structural modeling. We identified an E2F1-dependent gene regulatory network with IL6 as a central hub. E2F1-induced IL-6 secretion unleashes an autocrine inflammatory feedback loop driving invasiveness and epithelial-to-mesenchymal transition. IL-6-activated STAT3 physically interacts with E2F1 and cooperatively enhances IL-6 expression by binding to an E2F1-STAT3-responsive promoter element. The E2F1-STAT3/IL-6 axis strongly modulates the immune niche and generates a crosstalk with CD4+ cells resulting in transcriptional changes of immunoregulatory genes in melanoma and immune cells that is indicative of an inflammatory and immunosuppressive environment. Clinical data from TCGA demonstrated that elevated E2F1, STAT3, and IL-6 correlate with infiltration of Th2, while simultaneously blocking Th1 in primary and metastatic melanomas. Strikingly, E2F1 depletion reduces the secretion of typical type-2 cytokines thereby launching a Th2-to-Th1 phenotype shift towards an antitumor immune response. The impact of activated E2F1-STAT3/IL-6 axis on melanoma-immune cell communication and its prognostic/therapeutic value was validated by mathematical modeling. This study addresses important molecular aspects of the tumor-associated microenvironment in modulating immune responses, and will contribute significantly to the improvement of future cancer therapies.

The N-Terminal Region of the Transcription Factor E2F1 Contains a Novel Transactivation Domain and Recruits General Transcription Factor GTF2H2.

The transcription factor E2F1 is the principal target of the tumor suppressor pRB. E2F1 promotes cell proliferation by activating growth-promoting genes upon growth stimulation. In contrast, E2F1 contributes to tumor suppression by activating tumor suppressor genes, such as ARF, upon loss of pRB function, a major oncogenic change. The transactivation domain of E2F1 has previously been mapped to the C-terminal region. We show here that the N-terminal region of E2F1 is critical for the activation of tumor suppressor genes. Deletion of the N-terminal region dramatically compromised E2F1 activation of tumor suppressor genes. The N-terminal region showed transactivation ability when fused to the DNA-binding domain of GAL4. A search for novel interacting factors with the N-terminal region, using a yeast two-hybrid system, identified the general transcription factor GTF2H2. Overexpression of GTF2H2 enhanced E2F1 activation of tumor suppressor genes and induction of cell death. Conversely, the knockdown of GTF2H2 compromised both. E2F1 binding enhanced the binding of GTF2H2 to target promoters depending on the integrity of the N-terminal region. Taken together, these results suggest that the N-terminal region of E2F1 contains a novel transactivation domain that mediates the activation of tumor suppressor genes, at least in part, by recruiting GTF2H2.

ALYREF recruits ELAVL1 to promote colorectal tumorigenesis via facilitating RNA m5C recognition and nuclear export

ALYREF can recognize 5-methylcytosine (m5C) decoration throughout RNAs to regulate RNA metabolism. However, its implications in cancer and precise regulatory mechanisms remain largely elusive. Here, we demonstrated that ALYREF supported colorectal cancer (CRC) growth and migration. Integrated analysis of ALYREF-RIP-Bis-seq and transcriptome profiles identified ribosomal protein S6 kinase B2 (RPS6KB2) and regulatory-associated protein of mTOR (RPTOR) as ALYREF’s possible downstream effectors. Mechanistically, ALYREF formed a complex with ELAV like RNA binding protein 1 (ELAVL1) to cooperatively promote m5C recognition and nuclear export of the two mRNAs. Moreover, ALYREF protein was highly expressed in tumor tissues of CRC patients, which predicted their poor prognosis. E2F transcription factor 6 (E2F6)-mediated transactivation gave a molecular insight into ALYREF overexpression. Collectively, ALYREF recruits ELAVL1 to collaboratively facilitate m5C recognition and nuclear export of RPS6KB2 and RPTOR transcripts for colorectal tumorigenesis, providing RNA m5C methylation as promising therapeutic targets and prognostic biomarkers for CRC.

MiR-195-5p inhibits cisplatin resistance in lung adenocarcinoma by regulating DNA damage via targeting E2F7.

Lung adenocarcinoma (LUAD) emerges as one of the most lethal malignant tumors worldwide. Platinum-based combination chemotherapy remains one of the main methods for patients with advanced LUAD. Due to the resistance, the effect of this chemotherapy was not satisfactory. Therefore, studying the mechanism of cisplatin (DDP) resistance is essential for promoting the effect of this therapeutic strategy. Therefore, this work sought to probe the impact of E2F Transcription Factor 7 (E2F7) on LUAD resistance and the molecular regulatory mechanism. The mRNA expression level of the target gene E2F7 in LUAD was predicted by bioinformatics analysis, and regulatory miRNA upstream of the target gene was identified. The mRNA and protein expression of E2F7 in LUAD cells was detected through quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and Western blot, respectively. The expression of miR-195-5p in LUAD cells was measured via qRT-PCR. E2F7 high and low expression groups underwent enrichment analysis by utilizing Gene Set Enrichment Analysis software. The targeting relationship of miR-195-5p and E2F7 was validated by conducting a dual-luciferase reporter assay. The cell viability was tested through cell counting kit-8. The cell cycle was examined by flow cytometry. DNA damage level was determined via Comet assay and Western blot assay. The findings indicated that the mRNA and protein levels of E2F7 were high in LUAD. MiR-195-5p was the regulatory miRNA upstream of E2F7, and lowly expressed in LUAD. The cell experiments suggested that E2F7 advanced the DDP resistance of LUAD cells by repressing DNA damage. Finally, the rescue assay manifested that miR-195-5p overexpression could abate inhibition of E2F7 overexpression on the DNA damage and the DDP sensitivity of LUAD cells. MiR-195-5p raised the DDP sensitivity of LUAD cells by advancing the DNA damage in LUAD cells via inhibition of E2F7.

E2F1-induced upregulation of TROAP contributes to endometrial cancer progression.

To investigate the role of Trophinin-associated protein (TROAP) in endometrial cancer (EC) progression and elucidate how the transcription factor E2F transcription factor 1 (E2F1) modulates EC by upregulating TROAP expression. TROAP expression in EC tissues and cell lines was analyzed using bioinformatics databases, quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry. TROAP was knocked down in EC cells to assess its effects on proliferation, migration, invasion, and glycolysis. Potential transcription factors regulating TROAP were identified, and the relationship between E2F1 and TROAP gene regulation was examined using dual luciferase assay. In vivo tumor growth was evaluated using a mouse xenograft model. TROAP was overexpressed in EC tissues and cell lines compared with normal controls. High TROAP expression correlated with poor differentiation, advanced stage, lymph node metastasis, and worse overall survival in EC patients. Knockdown of TROAP inhibited the proliferation, migration, invasion, and glycolytic capacity of EC cells. E2F1 was identified as a transcriptional activator of TROAP. E2F1 overexpression enhanced TROAP expression and promoted EC cell proliferation, migration, and glycolysis in a TROAP-dependent manner. TROAP knockdown suppressed tumor growth in vivo. TROAP is transcriptionally activated by E2F1 and promotes EC progression by enhancing cell proliferation, metastasis, and glycolysis. The E2F1-TROAP axis may serve as a potential therapeutic target for EC treatment.

CHAC1 blockade suppresses progression of lung adenocarcinoma by interfering with glucose metabolism via hijacking PKM2 nuclear translocation.

Patients with lung adenocarcinoma (LUAD) generally have poor prognosis. Abnormal cellular energy metabolism is a hallmark of LUAD. Glutathione-specific gamma-glutamylcyclotransferase 1 (CHAC1) is a member of the γ-glutamylcyclotransferase family and an unfolded protein response pathway regulatory gene. Its biological function and molecular regulatory mechanism, especially regarding energy metabolism underlying LUAD, remain unclear. By utilizing tissue microarray and data from The Cancer Genome Atlas and Gene Expression Omnibus, we found that CHAC1 expression was markedly higher in LUAD tissues than in non-tumor tissues, and was positively correlated with poor prognosis. Phenotypically, CHAC1 overexpression enhanced the proliferation, migration, invasion, tumor sphere formation, and glycolysis ability of LUAD cells, resulting in tumor growth both in vitro and in vivo. Mechanistically, through a shotgun mass spectrometry-based proteomic approach and high-throughput RNA sequencing, we found that CHAC1 acted as a bridge connecting UBA2 and PKM2, enhancing the SUMOylation of PKM2. The SUMOylated PKM2 then transferred from the cytoplasm to the nucleus, activating the expression of glycolysis-related genes and enhancing the Warburg effect. Lastly, E2F Transcription Factor 1 potently activated CHAC1 transcription by directly binding to the CHAC1 promoter in LUAD cells. The results of this study implied that CHAC1 regulates energy metabolism and promotes glycolysis in LUAD progression.

Calcineurin-mediated dephosphorylation stabilizes E2F1 protein by suppressing binding of the FBXW7 ubiquitin ligase subunit

The transcription factor E2F1 serves as a regulator of the cell cycle and promotes cell proliferation. It is highly expressed in cancer tissues and contributes to their malignant transformation. Degradation by the ubiquitin-proteasome system may help to prevent such overexpression of E2F1 and thereby to suppress carcinogenesis. A detailed understanding of the mechanisms underlying E2F1 degradation may therefore inform the development of new cancer treatments. We here identified SCFFBXW7 as a ubiquitin ligase for E2F1 by comprehensive analysis. We found that phosphorylation of E2F1 at serine-403 promotes its binding to FBXW7 (F-box/WD repeat-containing protein 7) followed by its ubiquitination and degradation. Furthermore, calcineurin, a Ca2+/calmodulin-dependent serine-threonine phosphatase, was shown to stabilize E2F1 by mediating its dephosphorylation at serine-403 and thereby preventing FBXW7 binding. Treatment of cells with Ca2+ channel blockers resulted in downregulation of both E2F1 protein and the expression of E2F1 target genes, whereas treatment with the Ca2+ ionophore ionomycin induced upregulation of E2F1. Finally, the calcineurin inhibitor FK506 attenuated xenograft tumor growth in mice in association with downregulation of E2F1 in the tumor tissue. Impairment of the balance between the opposing actions of FBXW7 and calcineurin in the regulation of E2F1 abundance may therefore play an important role in carcinogenesis.

Insight into mammary gland development and tumor progression in an E2F5 conditional knockout mouse model

Development of breast cancer is linked to altered regulation of mammary gland developmental processes. A better understanding of normal mammary gland development can thus reveal possible mechanisms of how normal cells are re-programmed to become malignant. E2Fs 1-4 are part of the E2F transcription factor family with varied roles in mammary development, but little is known about the role of E2F5. A combination of scRNAseq and predictive signature tools demonstrated the presence of E2F5 in the mammary gland and showed changes in predicted activity during the various phases of mammary gland development. Testing the hypothesis that E2F5 regulates mammary function, we generated a mammary-specific E2F5 knockout mouse model, resulting in modest mammary gland development changes. However, after a prolonged latency the E2F5 conditional knockout mice developed highly metastatic mammary tumors. Whole genome sequencing revealed significant intertumor heterogeneity. RNAseq and protein analysis identified altered levels of Cyclin D1, with similarities to MMTV-Neu tumors, suggesting that E2F5 conditional knockout mammary glands and tumors may be dependent on Cyclin D1. Transplantation of the tumors revealed metastases to lymph nodes that were enriched through serial transplantation in immune competent recipients. Based on these findings, we propose that loss of E2F5 leads to altered regulation of Cyclin D1, which facilitates the development of metastatic mammary tumors after long latency. More importantly, this study demonstrates that conditional loss of E2F5 in the mammary gland leads to tumor formation, revealing its role as a transcription factor regulating a network of genes that normally result in a tumor suppressor function.

A mathematical treatment of the impact of p53 signalling on the expression of the transcription factor E2F in the CycE/Cdk2 subsystem in cancerous cells

Complex networks of proteins and genes control cell growth until mitosis. These components play crucial roles in determining the characteristics and timing of each reaction in the cell. A family of cyclins and cyclin-dependent kinases regulates the progression of the cell from one stage to the next, while certain inhibitors regulate cell proliferation, significantly impacting this process. We examine the impact of p53 protein production in the cyclin E/cyclin-dependent kinase 2 (CycE/CDK2) subsystem. Although the precise functioning of the p53 protein is not fully understood, it is known to exhibit pulsatile behaviour, triggered in response to DNA damage. Consequently, the expression of the p53 protein within the cell system increases with the severity of DNA damage. Similarly, levels of CycE/CDK2 are substantially elevated in instances of DNA damage.To investigate this subsystem, we have developed a mathematical model of the CycE/CDK2 subsystem, presented as non-linear ordinary differential equations. Our primary aim is to determine the conditions that could theoretically result in tumorigenesis. We conduct a dynamical systems analysis to investigate the presence of stable limit cycles, which indicate the standard operational states of cells. Our investigation reveals the levels of p53 protein at which the cell can correct defects, undergo apoptosis, or enter quiescence, and where the system exhibits a Hopf-bifurcation (limit cycles). This is the novelty of our study, as previous research has primarily focused on numerical simulations.Using MATLAB simulations, we produced various results in response to different expressions and concentrations of the p53 protein, allowing us to assess its influence on malignant cells. By altering the concentration of protein p53, we ascertain the specific cellular circumstances that facilitate its natural growth, self-correction in the presence of defective activity, and entry into a state of quiescence.This investigation is motivated by the significant role of oscillations in driving, controlling, and managing the cellular oversight machinery. These aspects are incorporated into developing a mathematical model that emulates cellular operations. From this research, we establish that E2F is a critical target to mitigate oncogenic activity, achievable by managing the pulsatile behaviour of the inhibitor p53 or inhibiting its production process within the cell machinery.

Identification of Hotspot Regions for Candidate Genes Associated with Peanut (Arachis hypogaea L.) Pod and Seed Size on Chromosome A05

The size of peanut pods and seeds, which directly affects yield and quality, also has significant implications for mechanized production and market efficiency. Identifying relevant loci and mining candidate genes is crucial for cultivating high-yield peanut varieties. In this study, we employed advanced generation recombinant inbred lines developed by crossbreeding Huayu 44 and DF12 as the experimental material. Quantitative trait locus (QTL) mapping for traits related to pod and seed size was conducted across six environments. A total of 44 QTLs were detected, distributed on chromosomes A02, A05, B04, B08, and B10. An enrichment region for multiple QTLs was also identified on chromosome A05 (19.28~52.32 cm). In this region, 10 KASP markers were developed, narrowing the enrichment area to two candidate gene hotspot regions of 600.9 kb and 721.2 kb. By combining gene prediction and functional annotation within the intervals, 10 candidate genes, including those encoding cytochrome P450 protein, polyamine synthase, mannose-1-phosphate guanylyltransferase, pentatricopeptide repeat protein, and E2F transcription factor, were identified as regulators of pod and seed size. This study provides technical support for the genetic improvement and key gene identification of peanut pod and seed size.

Transcription factor E2F4 facilitates SUMOylation to promote HCC progression through interaction with LIN9.

SUMOylation plays a crucial role in numerous cellular biological and pathophysiological processes associated with human disease; however, the mechanisms regulating the genes involved in SUMOylation remain unclear. In the present study, E2F transcription factor 4 (E2F4) was identified as an E2F member related to hepatocellular carcinoma (HCC) progression by public database analysis. It was found that E2F4 promoted the proliferation and invasiveness of HCC cells via SUMOylation using Soft agar and Transwell migration assays. Mechanistically, it was demonstrated that E2F4 upregulated the transcript and protein expression levels of baculoviral IAP repeat containing 5, cell division cycle associated 8 and DNA topoisomerase II α using western blotting. Furthermore, the interaction between E2F4 with lin‑9 DREAM multi‑vulva class B core complex component (LIN9) was explored by co‑immunoprecipitation, immunofluorescence co‑localization and bimolecular fluorescence complementation assays. Moreover, it was demonstrated that E2F4 promoted the progression of HCC cells via LIN9. Rescue experiments revealed that LIN9 facilitated the SUMOylation and proliferation of HCC cells, which was prevented by knocking down E2F4 expression. In conclusion, the findings of the present study indicated that E2F4 plays a major role in the proliferation of HCC cells and may be a potential therapeutic target in the future.

Deubiquitylase USP31 Induces Autophagy and Promotes the Progression in Lung Squamous Cell Carcinoma Cells by Stabilizing E2F1 Expression.

Autophagy exerts a vital role in the progression of lung squamous cell carcinoma (LUSC). Ubiquitin-specific peptidase 31 (USP31) has recently been found to be involved in the development of a variety of cancers. However, whether USP31 modulates autophagy in LUSC remains unclear. This study revealed that high levels of USP31 were discovered in LUSC tissue samples employing the Gene Expression Profiling Interactive Analysis (GEPIA) database, quantitative real- time PCR (qRT-PCR), and Western blot analysis. Cell proliferation was tested via cell counting kit 8 (CCK-8) as well as colony formation, demonstrating that USP31-stable knockdown reduced cell viability. Immunofluorescence analysis illustrated that USP31 knockdown blocked the occurrence of LUSC autophagy. Meanwhile, USP31 has been shown to stabilize the expression of E2F transcription factor 1 (E2F1) through the proteasome pathway. Furthermore, overexpressed E2F1 effectively eliminated the effect of USP31 knockdown on LUSC cell proliferation and autophagy. In summary, this investigation proved that USP31 promoted LUSC cell growth and autophagy, at least in part by stabilizing E2F1 expression, which provided a potential therapeutic gene for the treatment of LUSC.

The novel circFKBP8/miR-432-5p/E2F7 cascade functions as a regulatory network in breast cancer

BackgroundCircular RNAs (circRNAs) are capable of affecting breast cancer (BC) development. However, the role and underneath mechanism of circFKBP8 (also known as hsa_circ_0000915) in BC remain largely unknown.MethodsExpression analyses were performed using quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry (IHC) assays. Effects on cell functional phenotypes were determined by assessing cell proliferation, migratory capacity, invasion, and stemness in vitro. The relationship between microRNA (miR)-432-5p and circFKBP8 or E2F transcription factor 7 (E2F7) was examined by RNA pull-down, dual-luciferase reporter, and RNA immunoprecipitation (RIP) assays. Xenograft assays were used to identify the function of circFKBP8 in vivo.ResultsCircFKBP8 was presented at high levels in BC tissues and cells. High circFKBP8 expression was associated with worse overall survival in BC patients. CircFKBP8 suppression inhibited BC cell proliferation, migratory capacity, invasion and stemness in vitro. CircFKBP8 suppression blocked xenograft tumor growth in vivo. Mechanistically, circFKBP8 functioned as a miR-432-5p sponge to modulate E2F7 expression. CircFKBP8 modulated BC cell malignant behaviors by miR-432-5p, and miR-432-5p affected these cell phenotypes through E2F7.ConclusionOur observations prove that circFKBP8 promotes BC malignant phenotypes through the miR-432-5p/E2F7 cascade, offering a promising therapeutic and prognostic target for BC.

Relationship Between Changes in the Expression Levels of miR-134 and E2F6 in Mediating Control of Apoptosis in NMDA-Induced Glaucomatous Mice

Objective This investigation was to determine the relationship between changes in the expression levels of miR-134 and the E2F transcription factor 6 (E2F6) in mediating control of apoptosis in N-methyl-D-aspartate (NMDA)-induced glaucomatous mice. Methods Morphological and structural changes were quantitatively analyzed along with apoptosis in the retinal ganglion cell (RGC) layer, internal plexiform layer and RGCs. Glaucomatous RGCs were transfected, and cell viability and apoptosis were examined. The targeting relationship between miR-134 and E2F6 was analyzed, as well as their expression pattern. Results Intravitreal injection of NMDA induced a significant reduction in the number of RGCs and thinning of IPL thickness. miR-134 was highly expressed and E2F6 was lowly expressed in glaucoma mice. Suppression of miR-134 or E2F6 overexpression inhibited apoptosis in the glaucomatous RGCs and instead their proliferative activity. MiR-134 targeted inhibition of E2F6 expression. Suppressing rises in E2F6 expression reduced the interfering effect of miR-134 on glaucomatous RGC development. Conclusion Depleting miR134 expression increases, in turn, E2F6 expression levels and in turn reduces glaucomatous RGC apoptosis expression.

Histone demethylase KDM2A recruits HCFC1 and E2F1 to orchestrate male germ cell meiotic entry and progression

In mammals, the transition from mitosis to meiosis facilitates the successful production of gametes. However, the regulatory mechanisms that control meiotic initiation remain unclear, particularly in the context of complex histone modifications. Herein, we show that KDM2A, acting as a lysine demethylase targeting H3K36me3 in male germ cells, plays an essential role in modulating meiotic entry and progression. Conditional deletion of Kdm2a in mouse pre-meiotic germ cells results in complete male sterility, with spermatogenesis ultimately arrested at the zygotene stage of meiosis. KDM2A deficiency disrupts H3K36me2/3 deposition in c-KIT+ germ cells, characterized by a reduction in H3K36me2 but a dramatic increase in H3K36me3. Furthermore, KDM2A recruits the transcription factor E2F1 and its co-factor HCFC1 to the promoters of key genes required for meiosis entry and progression, such as Stra8, Meiosin, Spo11, and Sycp1. Collectively, our study unveils an essential role for KDM2A in mediating H3K36me2/3 deposition and controlling the programmed gene expression necessary for the transition from mitosis to meiosis during spermatogenesis.

Cucurbitacin I exerts its anticancer effects by inducing cell cycle arrest via the KAT2a-ube2C/E2F1 pathway and inhibiting HepG2-induced macrophage M2 polarization

Hepatocellular carcinoma (HCC) is one of the most common malignancies globally, particularly prevalent in China, where it accounts for nearly half of the world's new cases and deaths each year, but has limited therapeutic options. This study systematically investigated the impact of cucurbitacin I on HCC cell lines including SK-Hep-1, Huh-7, and HepG2. The results revealed that cucurbitacin I not only inhibited cell proliferation, cell migration and colony formation, but also induced apoptosis in HCC cells. The apoptotic induction was accompanied by a decrease in the expression of the anti-apoptotic factor B-cell lymphoma 2 (Bcl2), and an elevation in the expression levels of pro-apoptotic factors, including tumor protein p53 (P53), bcl2 associated X-apoptosis regulator (Bax), and caspase3 (Cas3). Additionally, cucurbitacin I caused cell cycle arrest by modulating the lysine acetyltransferase 2A (KAT2A)-E2F transcription factor 1 (E2F1)/Ubiquitin-conjugating enzyme E2 C (UBE2C) signaling axis. In terms of regulation on tumor microenvironment, cucurbitacin I was demonstrated the ability to inhibit HCC cell-induced M2 polarization of macrophages. This comprehensive study unveils the multifaceted anti-cancer mechanisms of cucurbitacin I, providing robust support for its potential application in the treatment of HCC, offering new avenues for the future development of HCC treatment strategies.

Molecular findings and virological assessment of bladder papillomavirus infection in cattle

Bovine and ovine papillomaviruses (BPVs – OaPVs) are infectious agents that have an important role in bladder carcinogenesis of cattle. In an attempt to better understand territorial prevalence of papillomavirus genotypes and gain insights into their molecular pathway(s), a virological assessment of papillomavirus infection was performed on 52 bladder tumors in cattle using droplet digital polymerase chain reaction (ddPCR), an improved version of conventional PCR. ddPCR detected and quantified BPV DNA and mRNAs in all tumor samples, showing that these viruses play a determinant role in bovine bladder carcinogenesis. OaPV DNA and mRNA were detected and quantified in 45 bladder tumors. BPV14, BPV13, BPV2, OaPV2, OaPV1, and OaPV3 were the genotypes most closely related to bladder tumors. ddPCR quantified BPV1 and OaPV4 DNA and their transcripts less frequently. Western blot analysis revealed a significant overexpression of the phosphorylated platelet derived growth factor β receptor (PDGFβR) as well as the transcription factor E2F3, which modulate cell cycle progression in urothelial neoplasia. Furthermore, significant overexpression of calpain1, a Cys protease, was observed in bladder tumors related to BPVs alone and in BPV and OaPV coinfection. Calpain1 has been shown to play a role in producing free transcription factors of the E2F family, and molecular findings suggest that calpain family members work cooperatively to mutually regulate their protease activities in cattle bladder tumors. Altogether, these results showed territorial prevalence of BPV and OaPV genotypes and suggested that PDGFβR and the calpain system appeared to be molecular partners of both BPVs and OaPVs.