RESUMEN

N6-Methyladenosine (m6A) modification and its regulators play critical roles in human cancers, but their functions and regulatory mechanisms in adenocarcinoma of the esophagogastric junction (AEG) remain unclear. Here, we identified that IGF2BP3 is the most significantly up-regulated m6A regulator in AEG tumors versus paired normal adjacent tissues from the expression profile of m6A regulators in a large cohort of AEG patients. Silencing IGF2BP3 inhibits AEG progression in vitro and in vivo. By profiling transcriptome-wide targets of IGF2BP3 and the m6A methylome in AEG, we found that IGF2BP3-mediated stabilization and enhanced expression of m6A-modified targets, including targets of the cell cycle pathway, such as CDC25A, CDK4, and E2F1, are critical for AEG progression. Mechanistically, the increased m6A modification of CDC25A accelerates the G1-S transition. Clinically, up-regulated IGF2BP3, METTL3, and CDC25A show a strong positive correlation in TCGA pan-cancer, including AEG. In conclusion, our study highlights the role of post-transcriptional regulation in modulating AEG tumor progression and elucidates the functional importance of the m6A/IGF2BP3/CDC25A axis in AEG cells.

Asunto(s)

Adenocarcinoma , Adenosina , Ciclo Celular , Neoplasias Esofágicas , Proteínas de Unión al ARN , Fosfatasas cdc25 , Humanos , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/genética , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patología , Adenosina/análogos & derivados , Adenosina/metabolismo , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patología , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Animales , Unión Esofagogástrica/metabolismo , Unión Esofagogástrica/patología , Línea Celular Tumoral , Ratones , Regulación Neoplásica de la Expresión Génica , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patología , Ratones Desnudos , Metiltransferasas/metabolismo , Metiltransferasas/genética

RESUMEN

The cell division cycle 25 phosphatases CDC25A, B and C regulate cell cycle transitions by dephosphorylating residues in the conserved glycine-rich loop of CDKs to activate their activity. Here, we present the cryo-EM structure of CDK2-cyclin A in complex with CDC25A at 2.7 Å resolution, providing a detailed structural analysis of the overall complex architecture and key protein-protein interactions that underpin this 86 kDa complex. We further identify a CDC25A C-terminal helix that is critical for complex formation. Sequence conservation analysis suggests CDK1/2-cyclin A, CDK1-cyclin B and CDK2/3-cyclin E are suitable binding partners for CDC25A, whilst CDK4/6-cyclin D complexes appear unlikely substrates. A comparative structural analysis of CDK-containing complexes also confirms the functional importance of the conserved CDK1/2 GDSEID motif. This structure improves our understanding of the roles of CDC25 phosphatases in CDK regulation and may inform the development of CDC25-targeting anticancer strategies.

Asunto(s)

Microscopía por Crioelectrón , Ciclina A , Quinasa 2 Dependiente de la Ciclina , Fosfatasas cdc25 , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/química , Fosfatasas cdc25/ultraestructura , Fosfatasas cdc25/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Quinasa 2 Dependiente de la Ciclina/química , Quinasa 2 Dependiente de la Ciclina/ultraestructura , Humanos , Ciclina A/metabolismo , Ciclina A/química , Unión Proteica , Modelos Moleculares , Secuencia de Aminoácidos

RESUMEN

BACKGROUND: This study investigated the impact of salvianolic acids, derived from Danshen, on melanoma cell growth. Specifically, we assessed the ability of salvianolic acid A (Sal A) to modulate melanoma cell proliferation. METHODS: We used human melanoma A2058 and A375 cell lines to investigate the effects of Sal A on cell proliferation and death by measuring bromodeoxyuridine incorporation and lactate dehydrogenase release. We assessed cell viability and cycle progression using water soluble tetrazolium salt-1 (WST-1) mitochondrial staining and propidium iodide. Additionally, we used a phospho-kinase array to investigate intracellular kinase phosphorylation, specifically measuring the influence of Sal A on checkpoint kinase-2 (Chk-2) via western blot analysis. RESULTS: Sal A inhibited the growth of A2058 and A375 cells dose-responsively and induced cell cycle arrest at the G2/M phase. Notably, Sal A selectively induces Chk-2 phosphorylation without affecting Chk-1, thereby degrading Chk-2-regulated genes Cdc25A and Cdc2. However, Sal A does not affect the Chk1-Cdc25C pathway. CONCLUSIONS: Salvianolic acids, especially Sal A, effectively hinder melanoma cell growth by inducing Chk-2 phosphorylation and disrupting G2/M checkpoint regulation.

Asunto(s)

Ácidos Cafeicos , Proliferación Celular , Quinasa de Punto de Control 2 , Lactatos , Melanoma , Fosfatasas cdc25 , Humanos , Quinasa de Punto de Control 2/metabolismo , Quinasa de Punto de Control 2/genética , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/genética , Melanoma/tratamiento farmacológico , Melanoma/metabolismo , Melanoma/genética , Melanoma/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Lactatos/farmacología , Lactatos/metabolismo , Ácidos Cafeicos/farmacología , Transducción de Señal/efectos de los fármacos , Fosforilación/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos

RESUMEN

Fangchinoline (FA) is an alkaloid derived from the traditional Chinese medicine Fangji. Numerous studies have shown that FA has a toxic effect on various cancer cells, but little is known about its toxic effects on germ cells, especially oocytes. In this study, we investigated the effects of FA on mouse oocyte maturation and its potential mechanisms. Our results showed that FA did not affect meiosis resumption but inhibited the first polar body extrusion. This inhibition is not due to abnormalities at the organelle level, such as chromosomes and mitochondrial, which was proved by detection of DNA damage and reactive oxygen species. Further studies revealed that FA arrested the oocyte at the metaphase I stage, and this arrest was not caused by abnormal kinetochore-microtubule attachment or spindle assembly checkpoint activation. Instead, FA inhibits the activity of anaphase-promoting complexes (APC/C), as evidenced by the inhibition of CCNB1 degeneration. The decreased activity of APC/C may be due to a reduction in CDC25B activity as indicated by the high phosphorylation level of CDC25B (Ser323). This may further enhance Maturation-Promoting Factor (MPF) activity, which plays a critical role in meiosis. In conclusion, our study suggests that the metaphase I arrest caused by FA may be due to abnormalities in MPF and APC/C activity.

Asunto(s)

Bencilisoquinolinas , Factor Promotor de Maduración , Meiosis , Mesotelina , Oocitos , Animales , Meiosis/efectos de los fármacos , Oocitos/efectos de los fármacos , Femenino , Bencilisoquinolinas/farmacología , Factor Promotor de Maduración/metabolismo , Ratones , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/genética , Ciclosoma-Complejo Promotor de la Anafase/metabolismo , Ratones Endogámicos ICR , Especies Reactivas de Oxígeno/metabolismo , Daño del ADN/efectos de los fármacos , Ciclina B1/metabolismo , Ciclina B1/genética

RESUMEN

PURPOSE: Multiple myeloma (MM) is an incurable hematological malignancy characterized by clonal proliferation of malignant plasma B cells in bone marrow, and its pathogenesis remains unknown. The aim of this study was to determine the role of kinesin family member 22 (KIF22) in MM and elucidate its molecular mechanism. METHODS: The expression of KIF22 was detected in MM patients based upon the public datasets and clinical samples. Then, in vitro assays were performed to investigate the biological function of KIF22 in MM cell lines, and subcutaneous xenograft models in nude mice were conducted in vivo. Chromatin immunoprecipitation (ChIP) and luciferase reporter assay were used to determine the mechanism of KIF22-mediated regulation. RESULTS: The results demonstrated that the expression of KIF22 in MM patients was associated with several clinical features, including gender (P = 0.016), LDH (P < 0.001), ß2-MG (P = 0.003), percentage of tumor cells (BM) (P = 0.002) and poor prognosis (P < 0.0001). Furthermore, changing the expression of KIF22 mainly influenced the cell proliferation in vitro and tumor growth in vivo, and caused G2/M phase cell cycle dysfunction. Mechanically, KIF22 directly transcriptionally regulated cell division cycle 25C (CDC25C) by binding its promoter and indirectly influenced CDC25C expression by regulating the ERK pathway. KIF22 also regulated CDC25C/CDK1/cyclinB1 pathway. CONCLUSION: KIF22 could promote cell proliferation and cell cycle progression by transcriptionally regulating CDC25C and its downstream CDC25C/CDK1/cyclinB1 pathway to facilitate MM progression, which might be a potential therapeutic target in MM.

Asunto(s)

Proteína Quinasa CDC2 , Ciclina B1 , Proteínas de Unión al ADN , Cinesinas , Mieloma Múltiple , Fosfatasas cdc25 , Animales , Femenino , Humanos , Masculino , Ratones , Persona de Mediana Edad , Proteína Quinasa CDC2/metabolismo , Proteína Quinasa CDC2/genética , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/genética , Línea Celular Tumoral , Proliferación Celular , Ciclina B1/metabolismo , Ciclina B1/genética , Progresión de la Enfermedad , Regulación Neoplásica de la Expresión Génica , Cinesinas/metabolismo , Cinesinas/genética , Ratones Endogámicos BALB C , Ratones Desnudos , Mieloma Múltiple/patología , Mieloma Múltiple/metabolismo , Mieloma Múltiple/genética , Pronóstico , Transducción de Señal

RESUMEN

BACKGROUND: Cell division cyclin 25C (CDC25C) is a protein that plays a critical role in the cell cycle, specifically in the transition from the G2 phase to the M phase. Recent research has shown that CDC25C could be a potential therapeutic target for cancers, particularly for hepatocellular carcinoma (HCC). However, the specific regulatory mechanisms underlying the role of CDC25C in HCC tumorigenesis and development remain incompletely understood. AIM: To explore the impact of CDC25C on cell proliferation and apoptosis, as well as its regulatory mechanisms in HCC development. METHODS: Hepa1-6 and B16 cells were transduced with a lentiviral vector containing shRNA interference sequences (LV-CDC25C shRNA) to knock down CDC25C. Subsequently, a xenograft mouse model was established by subcutaneously injecting transduced Hepa1-6 cells into C57BL/6 mice to assess the effects of CDC25C knockdown on HCC development in vivo. Cell proliferation and migration were evaluated using a Cell Counting Kit-8 cell proliferation assays and wound healing assays, respectively. The expression of endoplasmic reticulum (ER) stress-related molecules (glucose-regulated protein 78, X-box binding protein-1, and C/EBP homologous protein) was measured in both cells and subcutaneous xenografts using quantitative real-time PCR (qRT-PCR) and western blotting. Additionally, apoptosis was investigated using flow cytometry, qRT-PCR, and western blotting. RESULTS: CDC25C was stably suppressed in Hepa1-6 and B16 cells through LV-CDC25C shRNA transduction. A xenograft model with CDC25C knockdown was successfully established and that downregulation of CDC25C expression significantly inhibited HCC growth in mice. CDC25C knockdown not only inhibited cell proliferation and migration but also significantly increased the ER stress response, ultimately promoting ER stress-induced apoptosis in HCC cells. CONCLUSION: The regulatory mechanism of CDC25C in HCC development may involve the activation of ER stress and the ER stress-induced apoptosis signaling pathway.

Asunto(s)

Carcinogénesis , Carcinoma Hepatocelular , Estrés del Retículo Endoplásmico , Neoplasias Hepáticas , Fosfatasas cdc25 , Animales , Humanos , Masculino , Ratones , Apoptosis , Carcinogénesis/genética , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/genética , Línea Celular Tumoral , Movimiento Celular , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Ratones Endogámicos C57BL , ARN Interferente Pequeño/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto

RESUMEN

Lung cancer (LC) is the most prevalent cancer type, with a high mortality rate worldwide. The current treatment options for LC have not been particularly successful in improving patient outcomes. Yifei Sanjie (YFSJ), a well-applicated traditional Chinese medicine formula, is widely used to treat pulmonary diseases, especially LC, yet little is known about its molecular mechanisms. This study was conducted to explore the molecular mechanism by which YFSJ ameliorated LC progression. The A549, NCI-H1975, and Calu-3 cells were treated with the YFSJ formula and observed for colony number, apoptosis, migration, and invasion properties recorded via corresponding assays. The PRMT6-YBX1-CDC25A axis was tested and verified through luciferase reporter, RNA immunoprecipitation, and chromatin immunoprecipitation assays and rescue experiments. Our results demonstrated that YFSJ ameliorated LC cell malignant behaviors by increasing apoptosis and suppressing proliferation, migration, and invasion processes. We also noticed that the xenograft mouse model treated with YFSJ significantly reduced tumor growth compared with the control untreated group in vivo. Mechanistically, it was found that YFSJ suppressed the expression of PRMT6, YBX1, and CDC25A, while the knockdown of these proteins significantly inhibited colony growth, migration, and invasion, and boosted apoptosis in LC cells. In summary, our results suggest that YFSJ alleviates LC progression via the PRMT6-YBX1-CDC25A axis, confirming its efficacy in clinical use. The findings of our study provide a new regulatory network for LC growth and metastasis, which could shed new insights into pulmonary medical research.

Asunto(s)

Neoplasias Pulmonares , MicroARNs , Humanos , Animales , Ratones , Neoplasias Pulmonares/patología , Proliferación Celular/genética , Movimiento Celular/genética , Pulmón/patología , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Proteína 1 de Unión a la Caja Y/genética , Proteína 1 de Unión a la Caja Y/metabolismo , Proteínas Nucleares/genética , Proteína-Arginina N-Metiltransferasas/genética , Proteína-Arginina N-Metiltransferasas/metabolismo , Proteína-Arginina N-Metiltransferasas/uso terapéutico , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo

RESUMEN

Endometriosis refers to as an estrogen-dependent disease. Estrogen receptor ß (ERß), the main estrogen receptor subtype which is encoded by the estrogen receptor 2 (ESR2) gene, can mediate the action of estrogen in endometriosis. Although selective estrogen receptor modulators can target the ERß, they are not specific due to the wide distribution of ERß. Recently, long noncoding RNAs have been implicated in endometriosis. Therefore, we aim to explore and validate the downstream regulatory mechanism of ERß, and to investigate the potential role of long intergenic noncoding RNA 1018 (LINC01018) as a nonhormonal treatment for endometriosis. Our study demonstrates that the expression levels of ESR2 and LINC01018 are increased in ectopic endometrial tissues and reveals a significant positive correlation between the ESR2 and LINC01018 expression. Mechanistically, ERß directly binds to an estrogen response element located in the LINC01018 promoter region and activates LINC01018 transcription. Functionally, ERß can regulate the CDC25C/CDK1/CyclinB1 pathway and promote ectopic endometrial stromal cell proliferation via LINC01018 in vitro. Consistent with these findings, the knockdown of LINC01018 inhibits endometriotic lesion proliferation in vivo. In summary, our study demonstrates that the ERß/LINC01018/CDC25C/CDK1/CyclinB1 signaling axis regulates endometriosis progression.

Asunto(s)

Proteína Quinasa CDC2 , Proliferación Celular , Ciclina B1 , Endometriosis , Receptor beta de Estrógeno , ARN Largo no Codificante , Transducción de Señal , Fosfatasas cdc25 , Endometriosis/genética , Endometriosis/patología , Endometriosis/metabolismo , Femenino , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Humanos , Receptor beta de Estrógeno/genética , Receptor beta de Estrógeno/metabolismo , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Proteína Quinasa CDC2/genética , Proteína Quinasa CDC2/metabolismo , Proliferación Celular/genética , Transducción de Señal/genética , Ciclina B1/genética , Ciclina B1/metabolismo , Ratones , Animales , Endometrio/metabolismo , Endometrio/patología

RESUMEN

BACKGROUND: CDC25B, as a member of the cell cycle regulating protein family, is located in the cytoplasm and is involved in the transition of the cell cycle and mitosis. CDC25B is highly expressed in various tumors and is a newly discovered oncogene. This study aimed to investigate the impact of CDC25B on mitoxantrone resistance in stomach adenocarcinoma (STAD) and its possible mechanisms. METHODS: This study analyzed the expression of CDC25B and its potential transcription factor E2F3 in STAD, as well as the IC50 values of tumor tissues by bioinformatics analysis. Expression levels of CDC25B and E2F3 in STAD cells were measured by qRT-PCR. MTT was utilized to evaluate cell viability and IC50 values of STAD cells, and comet assay was utilized to analyze the level of DNA damage in STAD cells. Western blot was used to analyze the expression of DNA damage-related proteins. The targeting relationship between E2F3 and CDC25B was validated by dual-luciferase and ChIP assays. RESULTS: Bioinformatics analysis and molecular experiments showed that CDC25B and E2F3 were highly expressed in STAD, and CDC25B was enriched in the mismatch repair and nucleotide excision repair pathways. The IC50 values of tumor tissues with high expression of CDC25B were relatively high. Dual-luciferase and ChIP assays confirmed that CDC25B could be transcriptionally activated by E2F3. Cell experiments revealed that CDC25B promoted mitoxantrone resistance in STAD cells by regulating DNA damage. Further research found that low expression of E2F3 inhibited mitoxantrone resistance in STAD cells by DNA damage, but overexpression of CDC25B reversed the impact of E2F3 knockdown on mitoxantrone resistance in STAD cells. CONCLUSION: This study confirmed a novel mechanism by which E2F3/CDC25B mediated DNA damage to promote mitoxantrone resistance in STAD cells, providing a new therapeutic target for STAD treatment.

Asunto(s)

Adenocarcinoma , Neoplasias Gástricas , Humanos , Mitoxantrona/farmacología , Neoplasias Gástricas/tratamiento farmacológico , Neoplasias Gástricas/genética , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/genética , Daño del ADN , Mitosis , Luciferasas , Factor de Transcripción E2F3 , Fosfatasas cdc25/genética

RESUMEN

Alternative splicing (AS) has been implicated in cell cycle regulation and cancer, but the underlying mechanisms are poorly understood. The poly(U)-binding splicing factor 60 (PUF60) is essential for embryonic development and is overexpressed in multiple types of cancer. Here, we report that PUF60 promotes mitotic cell cycle and lung cancer progression by controlling AS of the cell division cycle 25C (CDC25C). Systematic analysis of splicing factors deregulated in lung adenocarcinoma (LUAD) identifies that elevated copy number and expression of PUF60 correlate with poor prognosis. PUF60 depletion inhibits LUAD cell-cycle G2/M transition, cell proliferation, and tumor development. Mechanistically, PUF60 knockdown leads to exon skipping enriched in mitotic cell cycle genes, including CDC25C. Exon 3 skipping in the full-length CDC25C results in nonsense-mediated mRNA decay and a decrease of CDC25C protein, thereby inhibiting cell proliferation. This study establishes PUF60 as a cell cycle regulator and an oncogenic splicing factor in lung cancer.

Asunto(s)

Adenocarcinoma del Pulmón , Neoplasias Pulmonares , Humanos , Adenocarcinoma del Pulmón/genética , Empalme Alternativo/genética , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Ciclo Celular/genética , División Celular , Línea Celular Tumoral , Neoplasias Pulmonares/genética , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo

RESUMEN

Esophageal squamous cell carcinoma (ESCC) is a serious malignancy with poor prognosis, necessitating identification of oncogenic mechanisms for novel therapeutic strategies. Recent studies have highlighted the significance of the transcription factor forkhead box K1 (FOXK1) in diverse biological processes and carcinogenesis of multiple malignancies, including ESCC. However, the molecular pathways underlying FOXK1's role in ESCC progression are not fully understood, and its potential role in radiosensitivity remains unclear. Here, we aimed to elucidate the function of FOXK1 in ESCC and explore the underlying mechanisms. Elevated FOXK1 expression levels were found in ESCC cells and tissues, positively correlated with TNM stage, invasion depth, and lymph node metastasis. FOXK1 markedly enhanced the proliferative, migratory and invasive capacities of ESCC cells. Furthermore, silencing FOXK1 resulted in heightened radiosensitivity by impeding DNA damage repair, inducing G1 arrest, and promoting apoptosis. Subsequent studies demonstrated that FOXK1 directly bound to the promoter regions of CDC25A and CDK4, thereby activating their transcription in ESCC cells. Moreover, the biological effects mediated by FOXK1 overexpression could be reversed by knockdown of either CDC25A or CDK4. Collectively, FOXK1, along with its downstream target genes CDC25A and CDK4, may serve as a promising set of therapeutic and radiosensitizing targets for ESCC.

Asunto(s)

Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Factores de Transcripción Forkhead , Humanos , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Quinasa 4 Dependiente de la Ciclina/genética , Quinasa 4 Dependiente de la Ciclina/metabolismo , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/radioterapia , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Regulación Neoplásica de la Expresión Génica , Pronóstico , Tolerancia a Radiación/genética , Activación Transcripcional

RESUMEN

Nasopharyngeal carcinoma (NPC) is a primary malignancy that originates from the nasopharyngeal region. It has been demonstrated that a decrease in the expression level of cell division cycle gene 25A (CDC25A) suppresses cell viability and induces apoptosis in a variety of different types of cancer. However, at present, the role of CDC25A in NPC has yet to be fully elucidated. Therefore, the aim of the present study was to investigate the role of CDC25A in NPC progression and to explore the potential underlying mechanism. Reverse transcription­quantitative PCR was performed to detect the relative mRNA levels of CDC25A and E2F transcription factor 1 (E2F1). Western blot analysis was subsequently used to determine the expression levels of CDC25A, Ki67, proliferating cell nuclear antigen (PCNA) and E2F1. CCK8 assay was employed to measure cell viability and flow cytometric analysis was employed to analyze the cell cycle. The binding sites between the CDC25A promoter and E2F1 were predicted using bioinformatics tools. Finally, luciferase reporter gene and chromatin immunoprecipitation assays were performed to verify the interaction between CDC25A and E2F1. The results obtained suggested that CDC25A is highly expressed in NPC cell lines and CDC25A silencing was found to inhibit cell proliferation, reduce the protein expression levels of Ki67 and PCNA and induce G1 arrest of NPC cells. Furthermore, E2F1 could bind CDC25A and positively regulate its expression at the transcriptional level. In addition, CDC25A silencing abolished the effects of E2F1 overexpression on cell proliferation and the cell cycle in NPC. Taken together, the findings of the present study showed that CDC25A silencing attenuated cell proliferation and induced cell cycle arrest in NPC and CDC25A was regulated by E2F1. Hence, CDC25A may be a promising therapeutic target for treatment of NPC.

Asunto(s)

Genes cdc , Neoplasias Nasofaríngeas , Humanos , Carcinoma Nasofaríngeo/patología , Antígeno Nuclear de Célula en Proliferación/metabolismo , Antígeno Ki-67/metabolismo , Línea Celular Tumoral , Proliferación Celular , Puntos de Control del Ciclo Celular/genética , Ciclo Celular , Neoplasias Nasofaríngeas/patología , Regulación Neoplásica de la Expresión Génica , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo

RESUMEN

Cyclin A and CDC25A are both activators of cyclin-dependent kinases (CDKs): cyclin A acts as an activating subunit of CDKs and CDC25A a phosphatase of the inhibitory phosphorylation sites of the CDKs. In this study, we uncovered an inverse relationship between the two CDK activators. As cyclin A is an essential gene, we generated a conditional silencing cell line using a combination of CRISPR-Cas9 and degron-tagged cyclin A. Destruction of cyclin A promoted an acute accumulation of CDC25A. The increase of CDC25A after cyclin A depletion occurred throughout the cell cycle and was independent on cell cycle delay caused by cyclin A deficiency. Moreover, we determined that the inverse relationship with cyclin A was specific for CDC25A and not for other CDC25 family members or kinases that regulate the same sites in CDKs. Unexpectedly, the upregulation of CDC25A was mainly caused by an increase in transcriptional activity instead of a change in the stability of the protein. Reversing the accumulation of CDC25A severely delayed G2-M in cyclin A-depleted cells. Taken together, these data provide evidence of a compensatory mechanism involving CDC25A that ensures timely mitotic entry at different levels of cyclin A.

Asunto(s)

Ciclina A , Quinasas Ciclina-Dependientes , Fosfatasas cdc25 , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Ciclo Celular , División Celular , Ciclina A/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Fosforilación

RESUMEN

Cell division regulators play a vital role in neural progenitor cell (NPC) proliferation and differentiation. Cell division cycle 25C (CDC25C) is a member of the CDC25 family of phosphatases which positively regulate cell division by activating cyclin-dependent protein kinases (CDKs). However, mice with the Cdc25c gene knocked out were shown to be viable and lacked the apparent phenotype due to genetic compensation by Cdc25a and/or Cdc25b. Here, we investigate the function of Cdc25c in developing rat brains by knocking down Cdc25c in NPCs using in utero electroporation. Our results indicate that Cdc25c plays an essential role in maintaining the proliferative state of NPCs during cortical development. The knockdown of Cdc25c causes early cell cycle exit and the premature differentiation of NPCs. Our study uncovers a novel role of CDC25C in NPC division and cell fate determination. In addition, our study presents a functional approach to studying the role of genes, which elicit genetic compensation with knockout, in cortical neurogenesis by knocking down in vivo.

Asunto(s)

Proteínas de Ciclo Celular , Células-Madre Neurales , Neurogénesis , Fosfatasas cdc25 , Animales , Ratas , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Ciclo Celular , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Diferenciación Celular/genética , Quinasas Ciclina-Dependientes/metabolismo , Regulación hacia Abajo/genética , Neurogénesis/genética , Neurogénesis/fisiología , Células-Madre Neurales/metabolismo

RESUMEN

During development, cortical neurons are produced in a temporally regulated sequence from apical progenitors, directly or indirectly, through the production of intermediate basal progenitors. The balance between these major progenitor types is critical for the production of the proper number and types of neurons, and it is thus important to decipher the cellular and molecular cues controlling this equilibrium. Here we address the role of a cell cycle regulator, the CDC25B phosphatase, in this process. We show that, in the developing mouse neocortex of both sex, deleting CDC25B in apical progenitors leads to a transient increase in the production of TBR1+ neurons at the expense of TBR2+ basal progenitors. This phenotype is associated with lengthening of the G2 phase of the cell cycle, the total cell cycle length being unaffected. Using in utero electroporation and cortical slice cultures, we demonstrate that the defect in TBR2+ basal progenitor production requires interaction with CDK1 and is because of the G2 phase lengthening in CDC25B mutants. Together, this study identifies a new role for CDC25B and G2 phase length in direct versus indirect neurogenesis at early stages of cortical development.SIGNIFICANCE STATEMENT This study is the first analysis of the function of CDC25B, a G2/M regulator, in the developing neocortex. We show that removing CDC25B function leads to a transient increase in neuronal differentiation at early stages, occurring simultaneously with a decrease in basal intermediate progenitors (bIPs). Conversely, a CDC25B gain of function promotes production of bIPs, and this is directly related to CDC25B's ability to regulate CDK1 activity. This imbalance of neuron/progenitor production is linked to a G2 phase lengthening in apical progenitors; and using pharmacological treatments on cortical slice cultures, we show that shortening the G2 phase is sufficient to enhance bIP production. Our results reveal the importance of G2 phase length regulation for neural progenitor fate determination.

Asunto(s)

Neocórtex , Células-Madre Neurales , Neurogénesis , Animales , Ratones , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Células-Madre Neurales/metabolismo , Neurogénesis/genética , Neuronas/metabolismo

RESUMEN

Circular RNAs (circRNAs) have been extensively studied in tumor development and treatment. CircZNF609 (hsa_circ_0000615) has been shown to serve as an oncogene in all kinds of solid tumors and may act as the novel biomarker in tumor diagnosis and therapy in tumor early diagnosis and therapy. However, the underlying character and mechanism of circZNF609 in cisplatin chemosensitivity and bladder cancer (BCa) development were unknown. The expression level of cell division cycle 25B (CDC25B), microRNA 1200 (miR-1200), and circZNF609 in BCa cells and tissues depended on quantitative real-time PCR (qRT-PCR). CDC25B protein level was assayed with Western blot. Functional assays in vitro and in vivo had been conducted to inspect the important role of circZNF609 on BCa progression and cisplatin chemosensitivity in BCa. RNA sequencing and online databases were used to predict the interactions among circZNF609, miR-1200, and CDC25B. Mechanistic exploration was confirmed by RNA pull-down assay, RNA fluorescence in situ hybridization (FISH) and Dual luciferase reporter assay. CircZNF609 expression was increased significantly in BCa cell lines and tissues. For BCa patients, increased expression of circZNF609 was correlated with a worse survival. In vitro and in vivo, enforced expression of circZNF609 enhanced BCa cells proliferation, migration, and cisplatin chemoresistance. Mechanistically, circZNF609 alleviated the inhibition effect on target CDC25B expression by sponging miR-1200. CircZNF609 promoted tumor growth through novel circZNF609/miR-1200/CDC25B axis, implying that circZNF609 has significant potential to act as a new diagnostic biomarker and therapeutic target in BCa. Enhancing cisplatin sensitivity is an important direction for bladder cancer management. 1. This research reveals that circZNF609 improves bladder cancer progression and inhibits cisplatin sensitivity by inducing G1/S cell cycle arrest via a novel miR-1200/CDC25B cascades. 2. CircZNF609 was confirmed associated with worse survival of bladder cancer patients. 3. CircZNF609 act as a prognostic biomarker for bladder cancer treatment.

Asunto(s)

MicroARNs , Neoplasias de la Vejiga Urinaria , Humanos , Cisplatino/farmacología , Cisplatino/uso terapéutico , MicroARNs/genética , MicroARNs/metabolismo , Hibridación Fluorescente in Situ , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/metabolismo , ARN Circular/genética , ARN Circular/metabolismo , Proliferación Celular/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo

RESUMEN

Cisplatin broadly functions as a routine treatment for lung adenocarcinoma (LUAD) patients. However, primary and acquired cisplatin resistances frequently occur in the treatment of LUAD patients, seriously affecting the therapeutic effect of cisplatin in patients. We intended to illustrate the impact of let-7c-5p/cell division cycle 25A (CDC25A) axis on cisplatin resistance in LUAD. Expression of let-7c-5p and CDC25A was analyzed via quantitative real-time polymerase chain reaction. The interaction between the two was verified by dual-luciferase reporter detection. For detecting half-maximal inhibitory concentration value of cisplatin in LUAD cells and cell proliferation, we separately applied Cell Counting Kit-8 and colony formation assays. Furthermore, we measured cell apoptosis and cell cycle distribution via flow cytometry, as well as cell cycle-related protein expression via Western blot. Let-7c-5p was evidently downregulated in LUAD, while CDC25A was remarkably upregulated. Let-7c-5p upregulation arrested LUAD cells to proliferate, stimulated cell apoptosis, and arrested cell cycle in G0/G1 phase, thus enhancing sensitivity of LUAD cells to cisplatin. In terms of mechanism, CDC25A was directly targeted by let-7c-5p, and the influence of let-7c-5p overexpression on LUAD proliferation, apoptosis, cell cycle, and cisplatin resistance could be reversed by CDC25A upregulation. Let-7c-5p improved sensitivity of LUAD cells to cisplatin by modulating CDC25A, and let-7c-5p/CDC25A axis was an underlying target for the intervention of LUAD cisplatin resistance.

Asunto(s)

Adenocarcinoma del Pulmón , Neoplasias Pulmonares , MicroARNs , Humanos , Cisplatino/farmacología , MicroARNs/genética , MicroARNs/metabolismo , Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/genética , Adenocarcinoma del Pulmón/metabolismo , Proliferación Celular , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo , Fosfatasas cdc25/farmacología

RESUMEN

BACKGROUND: Alternative splicing (AS) events are extensively involved in the progression of diverse tumors, but how serine/arginine-rich splicing Factor 10 (SRSF10) behaves in hepatocellular carcinoma (HCC) has not been sufficiently studied. We aimed to determine SRSF10 associated AS mechanisms and their effects on HCC progression. METHODS: The expression of SRSF10 in HCC tissues was examined, and the in vitro and in vivo functions of SRSF10 were investigated. The downstream AS targets were screened using RNA sequencing. The interaction between SRSF10 protein and exclusion of cell division cycle 25 A (CDC25A) mRNA was identified using RNA immunoprecipitation and crosslinking immunoprecipitation q-PCR. The effects of SRSF10 on CDC25A posttranslational modification, subcellular distribution, and protein stability were verified through coimmunoprecipitation, immunofluorescence, and western blotting. RESULTS: SRSF10 was enriched in HCC tissues and facilitated HCC proliferation, cell cycle, and invasion. RNA sequencing showed that SRSF10 promotes exon 6 exclusion of CDC25A pre-mRNA splicing. As a crucial cell cycle mediator, the exon-skipped isoform CDC25A(△E6) was identified to be stabilized and retained in the nucleus due to the deletion of two ubiquitination (Lys150, Lys169) sites in exon 6. The stabilized isoform CDC25A(△E6) derived from AS had stronger cell cycle effects on HCC tumorigenesis, and playing a more significant role than the commonly expressed longer variant CDC25A(L). Interestingly, SRSF10 activated the carcinogenesis role of CDC25A through Ser178 dephosphorylation to cause nuclear retention. Moreover, CDC25A(△E6) was verified to be indispensable for SRSF10 to promote HCC development in vitro and in vivo. CONCLUSIONS: We reveal a regulatory pattern whereby SRSF10 contributes to a large proportion of stabilized CDC25A(△E6) production, which is indispensable for SRSF10 to promote HCC development. Our findings uncover AS mechanisms such as CDC25A that might serve as potential therapeutic targets to treat HCC.

Asunto(s)

Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patología , Neoplasias Hepáticas/genética , Isoformas de Proteínas , Carcinogénesis/genética , Exones , Factores de Empalme Serina-Arginina/genética , Factores de Empalme Serina-Arginina/metabolismo , Proteínas Represoras/metabolismo , Proteínas de Ciclo Celular/genética , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo

RESUMEN

Circular RNA (circRNAs) Fibronectin Type III Domain Containing 3B (FNDC3B) (circFNDC3B) has been revealed to be involved in the progression of oesophageal squamous cell carcinoma (ESCC). Hence, the potential regulatory network of circFNDC3B in ESCC was further investigated. Levels of genes and proteins were examined by qRT-PCR and Western blot. In vitro assays were performed using colony formation assay, 5-Ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, wound healing assay, and transwell assay. The target relationship between miR-214-3p and circFNDC3B or cell division cycle 25 homologue A (CDC25A) was verified by dual-luciferase reporter and RIP assays. In vivo assay was carried out using the xenograft nude mice model. CircFNDC3B was highly expressed in ESCC, and high circFNDC3B expression was tightly associated with poor prognosis in ESCC patients. Functionally, circFNDC3B knockdown not only suppressed ESCC cell growth, migration and invasion in vitro, but hindered ESCC tumour growth in vivo. Mechanistically, circFNDC3B acted as a sponge for miR-214-3p to up-regulate the expression of its target CDC25A. Rescue experiments showed that miR-214-3p inhibitor reversed the anticancer effects of circFNDC3B knockdown. Moreover, forced expression of miR-214-3p suppressed the malignant phenotypes mentioned above, while this condition was abolished by CDC25A overexpression. CircFNDC3B silencing restrains the tumorigenesis of oesophageal squamous cell carcinoma through miR-214-3p/CDC25A axis, which opens a new window to the development of novel therapeutic strategy for ESCC patients.

Asunto(s)

Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , MicroARNs , Animales , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas de Esófago/patología , Regulación Neoplásica de la Expresión Génica , Humanos , Ratones , Ratones Desnudos , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo

RESUMEN

Glioblastoma is a malignant CNS tumor with an extremely poor prognosis. F-box protein 11 (FBXO11) has E3 ubiquitin ligase activity and participates in the pathogenesis of multiple tumors but the role and mechanism of FBXO11 activity in glioblastoma remain unknown. In this study, FBXO11 was first observed to be downregulated in glioblastoma tissues and cell lines. 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) and colony formation assays and enzyme linked immunosorbent assay (ELISA) demonstrated that overexpression of FBXO11 suppressed proliferation and aerobic glycolysis and induced cell cycle arrest in U251-MG and A172 cells. FBXO1 decreased cell division cycle 25 A (Cdc25A) expression through ubiquitin degradation in a coprecipitation assay. A Western blot assay validated FBXO11 suppression of PKM2 dephosphorylation and c-Myc-mediated aerobic glycolysis via reduction of Cdc25A. In addition, a rescue experiment revealed that FBXO11 suppressed proliferation and aerobic glycolysis, both of which were reversed by overexpression of Cdc25A. FBXO11 overexpression also inhibited tumorigenesis via suppressing Cdc25A expression in vivo. These findings indicate that FBXO11 suppresses cell proliferation and aerobic glycolysis in glioblastomas by mediating the ubiquitin degradation of Cdc25A thereby providing insight into mechanisms of glioblastoma tumorigenesis and identifying a new potential therapeutic strategy.

Asunto(s)

Proteínas F-Box , Glioblastoma , Carcinogénesis , Línea Celular Tumoral , Proliferación Celular , Proteínas F-Box/metabolismo , Glioblastoma/patología , Glucólisis , Humanos , Proteína-Arginina N-Metiltransferasas/metabolismo , Ubiquitina/metabolismo , Fosfatasas cdc25/genética , Fosfatasas cdc25/metabolismo