Elevating PLK1 overcomes BETi resistance in prostate cancer via triggering BRD4 phosphorylation-dependent degradation in mitosis.

Bromodomain-containing protein 4 (BRD4) has emerged as a promising therapeutic target in prostate cancer (PCa). Understanding the mechanisms of BRD4 stability could enhance the clinical response to BRD4-targeted therapy. In this study, we report that BRD4 protein levels are significantly decreased during mitosis in a PLK1-dependent manner. Mechanistically, we show that BRD4 is primarily phosphorylated at T1186 by the CDK1/cyclin B complex, recruiting PLK1 to phosphorylate BRD4 at S24/S1100, which are recognized by the APC/CCdh1 complex for proteasome pathway degradation. We find that PLK1 overexpression lowers SPOP mutation-stabilized BRD4, consequently rendering PCa cells re-sensitized to BRD4 inhibitors. Intriguingly, we report that sequential treatment of docetaxel and JQ1 resulted in significant inhibition of PCa. Collectively, the results support that PLK1-phosphorylated BRD4 triggers its degradation at M phase. Sequential treatment of docetaxel and JQ1 overcomes BRD4 accumulation-associated bromodomain and extra-terminal inhibitor (BETi) resistance, which may shed light on the development of strategies to treat PCa.

Hypoxia inhibits the iMo/cDC2/CD8+ TRMs immune axis in the tumor microenvironment of human esophageal cancer.

BACKGROUND: Esophageal cancer (ESCA) is a form of malignant tumor associated with chronic inflammation and immune dysregulation. However, the specific immune status and key mechanisms of immune regulation in this disease require further exploration. METHODS: To investigate the features of the human ESCA tumor immune microenvironment and its possible regulation, we performed mass cytometry by time of flight, single-cell RNA sequencing, multicolor fluorescence staining of tissue, and flow cytometry analyses on tumor and paracancerous tissue from treatment-naïve patients. RESULTS: We depicted the immune landscape of the ESCA and revealed that CD8+ (tissue-resident memory CD8+ T cells (CD8+ TRMs) were closely related to disease progression. We also revealed the heterogeneity of CD8+ TRMs in the ESCA tumor microenvironment (TME), which was associated with their differentiation and function. Moreover, the subset of CD8+ TRMs in tumor (called tTRMs) that expressed high levels of granzyme B and immune checkpoints was markedly decreased in the TME of advanced ESCA. We showed that tTRMs are tumor effector cells preactivated in the TME. We then demonstrated that conventional dendritic cells (cDC2s) derived from intermediate monocytes (iMos) are essential for maintaining the proliferation of CD8+ TRMs in the TME. Our preliminary study showed that hypoxia can promote the apoptosis of iMos and impede the maturation of cDC2s, which in turn reduces the proliferative capacity of CD8+ TRMs, thereby contributing to the progression of cancer. CONCLUSIONS: Our study revealed the essential antitumor roles of CD8+ TRMs and preliminarily explored the regulation of the iMo/cDC2/CD8+ TRM immune axis in the human ESCA TME.

Study on the mechanism of quercetin in Sini Decoction Plus Ginseng Soup to inhibit liver cancer and HBV virus replication through CDK1.

BACKGROUND: To explore the anti-tumor and anti-virus key active ingredients of Sini Decoction Plus Ginseng Soup (SNRS) and their mechanisms. METHODS: The main ingredients of SNRS were analyzed by network pharmacology, and quercetin was identified as the key active ingredient. Then, we obtained the targets of quercetin by using Drugbank, PharmMapper, and SwissTargetPrediction databases. Then, the targets of HBV-related hepatocellular carcinoma (HBV-related HCC) were obtained by using Genecards database. In addition, using the gene expression profiles of HBV-related HCC patients in GEO database and the genes with the greatest survival difference in GEPIA 2 database identified the potential targets of quercetin. In addition, the mechanism of potential genes was studied through GO, KEGG analysis, and PPI network. Using AUC and survival analysis to evaluate the diagnostic and prognostic value of cyclin-dependent kinase 1 (CDK1) and CCNB1. Finally, the effects of quercetin on proliferation of Hep3B and HepG2215 cells and the level of CDK1 and CCNB1 were verified in vitro. ELISA was used to measure the expression levels of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) after the intervention by quercetin for 24 h and 48 h in HepG2215 cell. RESULTS: The first 10 key ingredients of SNRS were identified, and quercetin was the most key ingredient. The 101 potential quercetin targets were identified for the treatment of HBV-related HCC. GO and KEGG showed that 101 potential target enrichment in cancer and cell cycle regulation. By Venn analysis, CDK1 and CCNB1 were intersection targets, which could be used as potential targets for the action of quercetin on HBV-related HCC. Moreover, the expression of CDK1 and CCNB1 was highly expressed in the high-risk group, while the OS rate was low. The 1-year, 3-year and 5-year area under the curve (AUC) curves of CDK1 and CCNB1 were 0.724, 0.676, 0.622 and 0.745, 0.678, 0.634, respectively. Moreover, experimental results also showed that quercetin inhibited cell proliferation and reduced CDK1 expression in Hep3B and HepG2215 cells. The expressions of HBsAg and HBeAg in HepG2215 cell supernatant and cell gradually decreased with the increase of intervention time of quercetin and CDK1 inhibitor. CONCLUSIONS: Quercetin is a key ingredient of anti-HBV-related HCC activity and inhibits HBV replication in SNRS by inhibiting CDK1.

Hyperactivation of p53 contributes to mitotic catastrophe in podocytes through regulation of the Wee1/CDK1/cyclin B1 axis.

Podocyte loss in glomeruli is a fundamental event in the pathogenesis of chronic kidney diseases. Currently, mitotic catastrophe (MC) has emerged as the main cause of podocyte loss. However, the regulation of MC in podocytes has yet to be elucidated. The current work aimed to study the role and mechanism of p53 in regulating the MC of podocytes using adriamycin (ADR)-induced nephropathy. In vitro podocyte stimulation with ADR triggered the occurrence of MC, which was accompanied by hyperactivation of p53 and cyclin-dependent kinase (CDK1)/cyclin B1. The inhibition of p53 reversed ADR-evoked MC in podocytes and protected against podocyte injury and loss. Further investigation showed that p53 mediated the activation of CDK1/cyclin B1 by regulating the expression of Wee1. Restraining Wee1 abolished the regulatory effect of p53 inhibition on CDK1/cyclin B1 and rebooted MC in ADR-stimulated podocytes via p53 inhibition. In a mouse model of ADR nephropathy, the inhibition of p53 ameliorated proteinuria and podocyte injury. Moreover, the inhibition of p53 blocked the progression of MC in podocytes in ADR nephropathy mice through the regulation of the Wee1/CDK1/cyclin B1 axis. Our findings confirm that p53 contributes to MC in podocytes through regulation of the Wee1/CDK1/Cyclin B1 axis, which may represent a novel mechanism underlying podocyte injury and loss during the progression of chronic kidney disorder.

ARID1A loss promotes RNA editing of CDK13 in an ADAR1-dependent manner.

BACKGROUND: ARID1A, a subunit of the SWI/SNF chromatin remodeling complex, is thought to play a significant role both in tumor suppression and tumor initiation, which is highly dependent upon context. Previous studies have suggested that ARID1A deficiency may contribute to cancer development. The specific mechanisms of whether ARID1A loss affects tumorigenesis by RNA editing remain unclear. RESULTS: Our findings indicate that the deficiency of ARID1A leads to an increase in RNA editing levels and alterations in RNA editing categories mediated by adenosine deaminases acting on RNA 1 (ADAR1). ADAR1 edits the CDK13 gene at two previously unidentified sites, namely Q113R and K117R. Given the crucial role of CDK13 as a cyclin-dependent kinase, we further observed that ADAR1 deficiency results in changes in the cell cycle. Importantly, the sensitivity of ARID1A-deficient tumor cells to SR-4835, a CDK12/CDK13 inhibitor, suggests a promising therapeutic approach for individuals with ARID1A-mutant tumors. Knockdown of ADAR1 restored the sensitivity of ARID1A deficient cells to SR-4835 treatment. CONCLUSIONS: ARID1A deficiency promotes RNA editing of CDK13 by regulating ADAR1.

Down-regulation of SLC14A1 in prostate cancer activates CDK1/CCNB1 and mTOR pathways and promotes tumor progression.

Prostate cancer (PCa) is the most common cancer among men in the United States and the leading cause of cancer-related death. The Solute Carrier Family 14 Member 1 (SLC14A1) is a member of urea transporters which are important for the regulation of urine concentration. However, the physiological significance of SLC14A1 in PCa still remains unclear. In the present study, via bioinformatics analysis and experiments, we found that expression of SLC14A1 is significantly decreased in PCa progression, which could be attributed to hypermethylation on SLC14A1 promoter region. Moreover, its low expression and hypermethylation on SLC14A1 promoter are closely related to the poor prognosis of PCa patients. On the other hand, overexpression of SLC14A1 inhibited cell proliferation and metastasis while its overexpression also suppressed CDK1/CCNB1 pathway and mTOR/MMP-9 signaling pathway. Additionally, SLC14A1 expression is enriched in prostate basal-type cells. In summary, our study indicates that its low expression level and promoter hypermethylation of SLC14A1 may represent novel indicators for PCa progression and prognosis, and SLC14A1 could inhibit the progression of PCa.

SRSF9 promotes cell proliferation and migration of glioblastoma through enhancing CDK1 expression.

BACKGROUND: Glioblastoma (GBM) is a highly aggressive and prevalent brain tumor that poses significant challenges in treatment. SRSF9, an RNA-binding protein, is essential for cellular processes and implicated in cancer progression. Yet, its function and mechanism in GBM need clarification. METHODS: Bioinformatics analysis was performed to explore differential expression of SRSF9 in GBM and its prognostic relevance to glioma patients. SRSF9 and CDK1 expression in GBM cell lines and patients' tissues were quantified by RT-qPCR, Western blot or immunofluorescence assay. The role of SRSF9 in GBM cell proliferation and migration was assessed by MTT, Transwell and colony formation assays. Additionally, transcriptional regulation of CDK1 by SRSF9 was investigated using ChIP-PCR and dual-luciferase assays. RESULTS: The elevated SRSF9 expression correlates to GBM stages and poor survival of glioma patients. Through gain-of-function and loss-of-function strategies, SRSF9 was demonstrated to promote proliferation and migration of GBM cells. Bioinformatics analysis showed that SRSF9 has an impact on cell growth pathways including cell cycle checkpoints and E2F targets. Mechanistically, SRSF9 appears to bind to the promoter of CDK1 gene and increase its transcription level, thus promoting GBM cell proliferation. CONCLUSIONS: These findings uncover the cellular function of SRSF9 in GBM and highlight its therapeutic potential for GBM.

A CDK1 phosphorylation site on Drosophila PAR-3 regulates neuroblast polarisation and sensory organ formation.

The generation of distinct cell fates during development depends on asymmetric cell division of progenitor cells. In the central and peripheral nervous system of Drosophila, progenitor cells respectively called neuroblasts or sensory organ precursors use PAR polarity during mitosis to control cell fate determination in their daughter cells. How polarity and the cell cycle are coupled, and how the cell cycle machinery regulates PAR protein function and cell fate determination is poorly understood. Here, we generate an analog sensitive allele of CDK1 and reveal that its partial inhibition weakens but does not abolish apical polarity in embryonic and larval neuroblasts and leads to defects in polarisation of fate determinants. We describe a novel in vivo phosphorylation of Bazooka, the Drosophila homolog of PAR-3, on Serine180, a consensus CDK phosphorylation site. In some tissular contexts, phosphorylation of Serine180 occurs in asymmetrically dividing cells but not in their symmetrically dividing neighbours. In neuroblasts, Serine180 phosphomutants disrupt the timing of basal polarisation. Serine180 phosphomutants also affect the specification and binary cell fate determination of sensory organ precursors as well as Baz localisation during their asymmetric cell divisions. Finally, we show that CDK1 phosphorylates Serine-S180 and an equivalent Serine on human PAR-3 in vitro.

KIF22 promotes multiple myeloma progression by regulating the CDC25C/CDK1/cyclinB1 pathway.

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.

NANOG regulate the JAK/STAT3 pathway to promote trophoblast cell migration and epithelial-mesenchymal transition (EMT) in hypertensive disorders of pregnancy (HDP) through protein interaction with CDK1.

PROBLEM: Hypertensive disorders of pregnancy (HDP) are a common pregnancy disease. NANOG and Cyclin-dependent kinase 1 (CDK1) are essential for regulating the function of cell proliferation and apoptosis. However, the mechanism of action in HDP is yet unclear. METHOD: The microarray dataset GSE6573 was downloaded from the GEO database. Emt-related gene set was downloaded from Epithelial-Mesenchymal Transition gene database 2.0 were screened differentially expressed genes by bioinformatics analysis. Pathway Commons and Scansite 4.0 databases were used to predict the interaction between proteins. Placental tissue samples were collected from HDP patients and patients with uneventful pregnancies. RT-qPCR, Western blot and immunohistochemistry were used to detect the expression of NANOG, CDK1, MMP-2, MMP-9, EMT markers and the JAK/STAT3 pathway proteins. Transfection NANOG overexpression/knockdown, and CDK1 knockdown into the human chorionic trophoblast cells (HTR-8/Svneo). CCK-8, Transwell and Wound-healing assay were used to evaluate cell proliferation, invasion and migration. CO-IP and GST pull-down assays were used to confirm the protein interaction. RESULTS: A total obtained seven EMT-related differentially expressed genes, wherein NANOG, NODAL and LIN28A had protein interaction. In the HDP patients' tissue found that NANOG and CDK1 had lower expression. NANOG overexpression promoted HTR-8/Svneo proliferation, migration and EMT, while NANOG knockdown had the opposite effect. Further a protein interaction between STAT3 and CDK1 with NANOG. NANOG overexpression downregulated the JAK/STAT3 pathway to promote HTR-8/Svneo proliferation, migration and EMT, which was reversed by CDK1 knockdown. CONCLUSIONS: NANOG downregulated the JAK/STAT3 pathway to promote trophoblast cell proliferation, migration and EMT through protein interaction with CDK1.

WTAP mediated m6A-modified circ_0056856 contributes to the proliferation, migration, and invasion of IL-22-stimulated human keratinocyte by miR-197-3p/CDK1 axis.

BACKGROUND: Psoriasis is a chronic inflammation-associated skin disorder, and interleukin-22 (IL-22) is involved in psoriasis pathogenesis by boosting the proliferation and migration of keratinocytes. Mounting evidence has shown that circRNAs might play an important role in several aspects of psoriasis. This study is designed to explore the role and mechanism of circ_0056856 in regulating the phenotypes of IL-22-induced keratinocytes (HaCaT cells). METHODS: Circ_0056856, microRNA-197-3p (miR-197-3p), Cyclin-dependent kinase 1 (CDK1), and Wilms tumor 1-associated protein (WTAP) levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, proliferation, migration, and invasion were analyzed using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Wound scratch, and Transwell assays. After being predicted by Circinteractome or TargetScan, binding between miR-197-3p and circ_0056856 or CDK1 was verified by a dual-luciferase reporter assay. CDK1 and WTAP protein levels were determined using Western blot. Interaction between WTAP and circ_0056856 was assessed using methylated RNA immunoprecipitation (MeRIP) assay. RESULTS: Increased circ_0056856, CDK1, and WTAP were observed in psoriasis patients and IL-22-treated HaCaT cells. Moreover, circ_0056856 knockdown might repress IL-22-induced HaCaT cell proliferation, migration, and invasion in vitro. In mechanism, circ_0056856 might function as a sponge of miR-197-3p to modulate CDK1 expression, and WTAP improved circ_0056856 expression via m6A methylation. CONCLUSION: WTAP-guided m6A modified circ_0056856 facilitates IL-22-stimulated HaCaT cell damage through the miR-197-3p/CDK1 axis, which could provide novel insights into psoriasis treatment.

Targeting leucine-rich PPR motif-containing protein/LRPPRC by 5,7,4'-trimethoxyflavone suppresses esophageal squamous cell carcinoma progression.

JAK2/STAT3/MYC axis is dysregulated in nearly 70 % of human cancers, but targeting this pathway therapeutically remains a big challenge in cancer therapy. In this study, genes associated with JAK2, STAT3, and MYC were analyzed, and potential target genes were selected. Leucine-rich PPR motif-containing protein (LRPPRC) whose function and regulation are not fully understood, emerged as one of top 3 genes in terms of RNA epigenetic modification. Here, we demonstrate LRPPRC may be an independent prognostic indicator besides JAK2, STAT3, and MYC. Mechanistically, LRPPRC impairs N6-methyladenosine (m6A) modification of JAK2, STAT3, and MYC to facilitate nuclear mRNA export and expression. Meanwhile, excess LRPPRC act as a scaffold protein binding to JAK2 and STAT3 to enhance stability of JAK2-STAT3 complex, thereby facilitating JAK2/STAT3/MYC axis activation to promote esophageal squamous cell carcinoma (ESCC) progression. Furthermore, 5,7,4'-trimethoxyflavone was verified to bind to LRPPRC, STAT3, and CDK1, dissociating LRPPRC-JAK2-STAT3 and JAK2-STAT3-CDK1 interaction, leading to impaired tumorigenesis in 4-Nitroquinoline N-oxide induced ESCC mouse models and suppressed tumor growth in ESCC patient derived xenograft mouse models. In summary, this study suggests regulation of m6A modification by LRPPRC, and identifies a novel triplex target compound, suggesting that targeting LRPPRC-mediated JAK2/STAT3/MYC axis may overcome JAK2/STAT3/MYC dependent tumor therapeutic dilemma.

Knockdown of NFIC Promotes Bovine Myoblast Proliferation through the CENPF/CDK1 Axis.

As cellular transcription factors and DNA replicators, nuclear factor I (NFI) family members play an important role in mammalian development. However, there is still a lack of research on the muscle regeneration of NFI family members in cattle. In this study, the analysis of NFI family factors was conducted on their characterization, phylogenetics, and functional domains. We found that NFI family members were relatively conserved among different species, but there was heterogeneity in amino acid sequences, DNA coding sequences, and functional domain among members. Furthermore, among NFI family factors, we observed that NFIC exhibited highly expression in bovine muscle tissues, particularly influencing the expression of proliferation marker genes in myoblasts. To investigate the influence of NFIC on myoblast proliferation, we knocked down NFIC (si-NFIC) and found that the proliferation of myoblasts was significantly promoted. In terms of regulation mechanism, we identified that si-NFIC could counteract the inhibitory effect of the cell cycle inhibitor RO-3306. Interestingly, CENPF, as the downstream target gene of NFIC, could affect the expression of CDK1, CCNB1, and actively regulate the cell cycle pathway and cell proliferation. In addition, when CENPF was knocked down, the phosphorylation of p53 and the expression of Bax were increased, but the expression of Bcl2 was inhibited. Our findings mainly highlight the mechanism by which NFIC acts on the CENPF/CDK1 axis to regulate the proliferation of bovine myoblasts.

Multiple intersecting pathways are involved in CPEB1 phosphorylation and regulation of translation during mouse oocyte meiosis.

The RNA-binding protein cytoplasmic polyadenylation element binding 1 (CPEB1) plays a fundamental role in regulating mRNA translation in oocytes. However, the specifics of how and which protein kinase cascades modulate CPEB1 activity are still controversial. Using genetic and pharmacological tools, and detailed time courses, we have re-evaluated the relationship between CPEB1 phosphorylation and translation activation during mouse oocyte maturation. We show that both the CDK1/MAPK and AURKA/PLK1 pathways converge on CPEB1 phosphorylation during prometaphase of meiosis I. Only inactivation of the CDK1/MAPK pathway disrupts translation, whereas inactivation of either pathway alone leads to CPEB1 stabilization. However, CPEB1 stabilization induced by inactivation of the AURKA/PLK1 pathway does not affect translation, indicating that destabilization and/or degradation is not linked to translational activation. The accumulation of endogenous CCNB1 protein closely recapitulates the translation data that use an exogenous template. These findings support the overarching hypothesis that the activation of translation during prometaphase in mouse oocytes relies on a CDK1/MAPK-dependent CPEB1 phosphorylation, and that translational activation precedes CPEB1 destabilization.

Japanese encephalitis virus NS1 and NS1' proteins induce vimentin rearrangement via the CDK1-PLK1 axis to promote viral replication.

The host cytoskeleton plays crucial roles in various stages of virus infection, including viral entry, transport, replication, and release. However, the specific mechanisms by which intermediate filaments are involved in orthoflavivirus infection have not been well understood. In this study, we demonstrate that the Japanese encephalitis virus (JEV) remodels the vimentin network, resulting in the formation of cage-like structures that support viral replication. Mechanistically, JEV NS1 and NS1' proteins induce the translocation of CDK1 from the nucleus to the cytoplasm and interact with it, leading to the phosphorylation of vimentin at Ser56. This phosphorylation event recruits PLK1, which further phosphorylates vimentin at Ser83. Consequently, these phosphorylation modifications convert the typically filamentous vimentin into non-filamentous "particles" or "squiggles." These vimentin "particles" or "squiggles" are then transported retrogradely along microtubules to the endoplasmic reticulum, where they form cage-like structures. Notably, NS1' is more effective than NS1 in triggering the CDK1-PLK1 cascade response. Overall, our study provides new insights into how JEV NS1 and NS1' proteins manipulate the vimentin network to facilitate efficient viral replication. IMPORTANCE: Japanese encephalitis virus (JEV) is a mosquito-borne orthoflavivirus that causes severe encephalitis in humans, particularly in Asia. Despite the availability of a safe and effective vaccine, JEV infection remains a significant public health threat due to limited vaccination coverage. Understanding the interactions between JEV and host proteins is essential for developing more effective antiviral strategies. In this study, we investigated the role of vimentin, an intermediate filament protein, in JEV replication. Our findings reveal that JEV NS1 and NS1' proteins induce vimentin rearrangement, resulting in the formation of cage-like structures that envelop the viral replication factories (RFs), thus facilitating efficient viral replication. Our research highlights the importance of the interplay between the cytoskeleton and orthoflavivirus, suggesting that targeting vimentin could be a promising approach for the development of antiviral strategies to inhibit JEV propagation.

CDK1-PP2A-B55 interplay ensures cell cycle oscillation via Apc1-loop300.

Cell cycle control relies on a delicate balance of phosphorylation with CDK1 and phosphatases like PP1 and PP2A-B55. Yet, identifying the primary substrate responsible for cell cycle oscillations remains a challenge. We uncover the pivotal role of phospho-regulation in the anaphase-promoting complex/cyclosome (APC/C), particularly through the Apc1-loop300 domain (Apc1-300L), orchestrated by CDK1 and PP2A-B55. Premature activation of PP2A-B55 during mitosis, induced by Greatwall kinase depletion, leads to Apc1-300L dephosphorylation, stalling APC/C activity and delaying Cyclin B degradation. This effect can be counteracted using the B55-specific inhibitor pEnsa or by removing Apc1-300L. We also show Cdc20's dynamic APC/C interaction across cell cycle stages, but dephosphorylation of Apc1-300L specifically inhibits further Cdc20 recruitment. Our study underscores APC/C's central role in cell cycle oscillation, identifying it as a primary substrate regulated by the CDK-PP2A partnership.

CDK1 and CCNA2 play important roles in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is a malignant tumor that occurs in oral cavity and is dominated by squamous cells. The relationship between CDK1, CCNA2, and OSCC is still unclear. The OSCC datasets GSE74530 and GSE85195 configuration files were downloaded from the Gene Expression Omnibus (GEO) database and were derived from platforms GPL570 and GPL6480. Differentially expressed genes (DEGs) were screened. The weighted gene co-expression network analysis, functional enrichment analysis, gene set enrichment analysis, construction and analysis of protein-protein interaction (PPI) network, Comparative Toxicogenomics Database analysis were performed. Gene expression heatmap was drawn. TargetScan was used to screen miRNAs that regulate central DEGs. A total of 1756 DEGs were identified. According to Gene Ontology (GO) analysis, they were predominantly enriched in processes related to organic acid catabolic metabolism, centromeric, and chromosomal region condensation, and oxidoreductase activity. In Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the DEGs were mainly concentrated in metabolic pathways, P53 signaling pathway, and PPAR signaling pathway. Weighted gene co-expression network analysis was performed with a soft-thresholding power set at 9, leading to the identification of 6 core genes (BUB1B, CCNB1, KIF20A, CCNA2, CDCA8, CDK1). The gene expression heatmap revealed that core genes (CDK1, CCNA2) were highly expressed in OSCC samples. Comparative Toxicogenomics Database analysis demonstrated associations between the 6 genes (BUB1B, CCNB1, KIF20A, CCNA2, CDCA8, CDK1) and oral tumors, precancerous lesions, inflammation, immune system disorders, and tongue tumors. The associated miRNAs for CDK1 gene were hsa-miR-203a-3p.2, while for CCNA2 gene, they were hsa-miR-6766-3p, hsa-miR-4782-3p, and hsa-miR-219a-5p. CDK1 and CCNA2 are highly expressed in OSCC. The higher the expression of CDK1 and CCNA2, the worse the prognosis.

LncRNA NR_030777 promotes mitophagy by targeting CDK1-related mitochondrial fission and ATG12 to attenuate paraquat-induced Parkinson's disease.

With the evidence emerging that abnormal expression of long noncoding RNAs (lncRNAs) are involved in onset of Parkinson's disease (PD), the role of NR_030777 contributing to this disease is of great interest. We recently found that a novel lncRNA "NR_030777" demonstrates protective effects on PQ-induced neurodegeneration. However, the underlying molecular mechanisms of NR_030777 in the regulation of mitochondrial fission and mitophagy involved in PQ-induced neuronal damage remain to be explored. NR_030777 brain conditional overexpressing mice as well as in vitro primary neuronal cells from cerebral cortex and Neuro2a cells were adopted. Immunofluorescence, Immunohistochemistry, qRT-PCR and Western blotting were used to evaluate the expression levels of RNA and proteins. RNA immunoprecipitation and RNA pulldown experiment were used to evaluate the interaction of NR_030777 with its target proteins. NR_030777 and mitophagy were increased, and tyrosine hydroxylase (TH) levels recovered after NR_030777 overexpression upon PQ treatment. The overexpression and knockdown of NR_030777 unveiled that NR_030777 positively regulated mitophagy such as the upregulation of LC3B-II:I, ATG12-ATG5, p62 and NBR1. Moreover, the application of mdivi-1, a DRP-1 inhibitor, in combination with NR_030777 genetic modified cells unveiled that NR_030777 promoted DRP1-mediated mitochondrial fission and mitophagy. Furthermore, NR_030777 were directly bound to CDK1 to increase p-DRP1 levels at the Ser616 site, leading to mitochondrial fission and mitophagy. On the other hand, NR_030777 acted directly on ATG12 within the ATG12-ATG5 complex in the 800-1400 nt region to modulate the membrane formation. Accordingly, NR_030777 deficiency in neuron cells compromised cell mitophagy. Finally, the above findings were confirmed using NR_030777-overexpressing mice. NR_030777 exerted a protective effect on PQ-exposed mice by enhancing mitophagy. Our data provide the first scientific evidence for the precise invention of PQ-induced PD. Our findings further propose a breakthrough for understanding the regulatory relationship between NR_030777, CDK1, ATG12 and mitophagy in PQ-induced PD.

Lethal Giant Disc is a target of Cdk1 and regulates ESCRT-III localization during germline stem cell abscission.

Abscission is the final step of cytokinesis that allows the physical separation of sister cells through the scission of the cellular membrane. This deformation is driven by ESCRT-III proteins, which can bind membranes and form dynamic helices. A crucial step in abscission is the recruitment of ESCRT-III proteins at the right time and place. Alix is one of the best characterized proteins that recruits ESCRT-III proteins from yeast to mammals. However, recent studies in vivo have revealed that pathways acting independently or redundantly with Alix are also required at abscission sites in different cellular contexts. Here, we show that Lgd acts redundantly with Alix to properly localize ESCRT-III to the abscission site in germline stem cells (GSCs) during Drosophila oogenesis. We further demonstrate that Lgd is phosphorylated at multiple sites by the CycB/Cdk1 kinase. We found that these phosphorylation events potentiate the activity of Shrub, a Drosophila ESCRT-III, during abscission of GSCs. Our study reveals that redundancy between Lgd and Alix, and coordination with the cell cycle kinase Cdk1, confers robust and timely abscission of Drosophila germline stem cells.

Molecular mechanisms of Codonopsis pilosula in inhibiting hepatocellular carcinoma growth and metastasis.

BACKGROUND: Liver cancer, one of the most common types of cancer worldwide, accounts for millions of cases annually. With its multi-target and wide-ranging therapeutic effects, traditional Chinese medicine has emerged as a potential approach for treating various tumors. Codonopsis pilosula, a traditional herb, is known for its anti-inflammatory and antioxidant properties. In this study, we investigated the potential molecular mechanisms of Codonopsis pilosula in regulating the inhibition of CDK1 and the modulation of PDK1/ß-catenin, which are involved in hepatocellular carcinoma growth and metastasis. STUDY DESIGN/METHODS: Firstly, we screened the active chemical constituents of Codonopsis pilosula and identified their respective target proteins using the Herb database. Then, we applied the GeneCards database and transcriptome sequencing analysis to screen for critical genes associated with the occurrence and development of liver cancer. The intersection of the target proteins and disease-related genes was used to determine the potential targets of Codonopsis pilosula in hepatocellular carcinoma. Protein-protein interaction analysis and GO/KEGG analysis were subsequently performed to uncover the pathways through which Codonopsis pilosula acts on liver cancer. The Huh-7 cell line, exhibiting the highest sensitivity to Codonopsis pilosula polysaccharide solution (CPP) intervention, was chosen for subsequent studies. Cell viability was evaluated using the CCK-8 assay, colony formation assay was conducted to determine cell proliferation capacity, flow cytometry was used to analyze cell cycle, TUNEL staining was performed to assess cell apoptosis, scratch assay was carried out to evaluate cell migration ability, the expression of EMT-related proteins was detected and analyzed, and cell sphere formation assay was conducted to investigate cell stemness. Finally, a liver cancer animal model was established, and different doses of CPP were administered via gavage the next day. The expression levels of CDK1, PDK1, and ß-catenin in mouse liver tissues were detected and analyzed, immunohistochemistry staining was performed to assess the expression of tumor cell proliferation-related proteins Ki67 and PCNA in mouse xenografts, and TUNEL staining was carried out to evaluate cell apoptosis in mouse liver tissues. After intervention with CDK1 expression, the expression levels of CDK1, PDK1, and ß-catenin proteins and mRNA in each group of cells were detected using Western blot and RT-qPCR. RESULTS: Through network pharmacology analysis, transcriptome sequencing, and bioinformatics analysis, 35 target genes through which Codonopsis pilosula acts on liver cancer were identified. Among them, CDK1, with the highest degree in the PPI network, was considered an essential target protein for Codonopsis pilosula in treating liver cancer. In vitro cell experiments revealed that CPP could inhibit the expression of CDK1/PDK1/ß-catenin signaling axis factors, suppress cell proliferation, decrease cell migration ability, influence the EMT process, and reduce cell stemness by inhibiting CDK1 and affecting the PDK1/ß-catenin signaling axis. Similarly, in vivo experiments demonstrated that CPP could regulate the CDK1/PDK1/ß-catenin signaling axis, inhibit tumor growth, and induce cell apoptosis. CONCLUSION: Codonopsis pilosula may inhibit hepatocellular carcinoma growth by suppressing CDK1 and affecting the PDK1/ß-catenin signaling axis, limiting cell EMT and reducing cell stemness. These findings provide insights into the potential therapeutic role of Codonopsis pilosula in liver cancer.