A novel selenium analog of HDACi-based twin drug induces apoptosis and cell cycle arrest via CDC25A to improve prostate cancer therapy.

Cancer therapy has moved from single agents to more mechanism-based targeted approaches. In recent years, the combination of HDAC inhibitors and other anticancer chemicals has produced exciting progress in cancer treatment. Herein, we developed a novel prodrug via the ligation of dichloroacetate to selenium-containing potent HDAC inhibitors. The effect and mechanism of this compound in the treatment of prostate cancer were also studied. Methods: The concerned prodrug SeSA-DCA was designed and synthesized under mild conditions. This compound's preclinical studies, including the pharmacokinetics, cell toxicity, and anti-tumor effect on prostate cancer cell lines, were thoroughly investigated, and its possible synergistic mechanism was also explored and discussed. Results: SeSA-DCA showed good stability in physiological conditions and could be rapidly decomposed into DCA and selenium analog of SAHA (SeSAHA) in the tumor microenvironment. CCK-8 experiments identified that SeSA-DCA could effectively inhibit the proliferation of a variety of tumor cell lines, especially in prostate cancer. In further studies, we found that SeSA-DCA could also inhibit the metastasis of prostate cancer cell lines and promote cell apoptosis. At the animal level, oral administration of SeSA-DCA led to significant tumor regression without obvious toxicity. Moreover, as a bimolecular coupling compound, SeSA-DCA exhibited vastly superior efficacy than the mixture with equimolar SeSAHA and DCA both in vitro and in vivo. Our findings provide an important theoretical basis for clinical prostate cancer treatment. Conclusions: Our in vivo and in vitro results showed that SeSA-DCA is a highly effective anti-tumor compound for PCa. It can effectively induce cell cycle arrest and growth suppression and inhibit the migration and metastasis of PCa cell lines compared with monotherapy. SeSA-DCA's ability to decrease the growth of xenografts is a little better than that of docetaxel without any apparent signs of toxicity. Our findings provide an important theoretical basis for clinical prostate cancer treatment.

Inhibition of Melanoma Cell Growth by Salvianolic Acid A through CHK2-CDC25A Pathway Modulation.

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.

P53-Independent G1-Cell Cycle Arrest Increases SARS-CoV-2 RNA Replication.

While having already killed more than 7 million of people worldwide in 4 years, SARS-CoV-2, the etiological agent of COVID-19, is still circulating and evolving. Understanding the pathogenesis of the virus is of capital importance. It was shown that in vitro and in vivo infection with SARS-CoV-2 can lead to cell cycle arrest but the effect of the cell cycle arrest on the virus infection and the associated mechanisms are still unclear. By stopping cells in the G1 phase as well as targeting several pathways involved using inhibitors and small interfering RNAs, we were able to determine that the cell cycle arrest in the late G1 is beneficial for SARS-CoV-2 replication. This cell cycle arrest is independent of p53 but is dependent on the CDC25A-CDK2/cyclin E pathway. These data give a new understanding in SARS-CoV-2 pathogenesis and highlight some possible targets for the development of novel therapeutic approaches.

Ginsenoside 20(S)-Rg3 reduces KIF20A expression and promotes CDC25A proteasomal degradation in epithelial ovarian cancer.

Background: Ginsenoside 20(S)-Rg3 shows promising tumor-suppressive effects in ovarian cancer via inhibiting NF-κB signaling. This study aimed to explore the downstream tumor suppressive mechanisms of ginsenoside Rg3 via this signaling pathway. Materials and methods: A systematical screening was applied to examine the expression profile of 41 kinesin family member genes in ovarian cancer. The regulatory effect of ginsenoside Rg3 on KIF20A expression was studied. In addition, we explored interacting proteins of KIF20A and their molecular regulations in ovarian cancer. RNA-seq data from The Cancer Genome Atlas (TCGA) was used for bioinformatic analysis. Epithelial ovarian cancer cell lines SKOV3 and A2780 were used as in vitro and in vivo cell models. Commercial human ovarian cancer tissue arrays were used for immunohistochemistry staining. Results: KIF20A is a biomarker of poor prognosis among the kinesin genes. It promotes ovarian cancer cell growth in vitro and in vivo. Ginsenoside Rg3 can suppress the transcription of KIF20A. GST pull-down and co-immunoprecipitation (IP) assays confirmed that KIF20A physically interacts with BTRC (ß-TrCP1), a substrate recognition subunit for SCFß-TrCP E3 ubiquitin ligase. In vitro ubiquitination and cycloheximide (CHX) chase assays showed that via interacting with BTRC, KIF20A reduces BTRC-mediated CDC25A poly-ubiquitination and enhances its stability. Ginsenoside Rg3 treatment partly abrogates KIF20A overexpression-induced CDC25A upregulation. Conclusion: This study revealed a novel anti-tumor mechanism of ginsenoside Rg3. It can inhibit KIF20A transcription and promote CDC25A proteasomal degradation in epithelial ovarian cancer.

Usf2 Deficiency Promotes Autophagy to Alleviate Cerebral Ischemia-Reperfusion Injury Through Suppressing YTHDF1-m6A-Mediated Cdc25A Translation.

Autophagy has been involved in protection of ischemia/reperfusion (I/R)-induced injury in many tissues including the brain. The upstream stimulatory factor 2 (Usf2) was proposed as a regulator in aging and degenerative brain diseases; however, the its role in autophagy during cerebral I/R injury remains unclear. Here, the middle cerebral artery occlusion (MCAO) operation was applied to establish an I/R mouse model. We showed that Usf2 was significantly upregulated in I/R-injured brain, accompanied by decreased levels of autophagy. Then, oxygen-glucose deprivation/recovery (OGD/R) treatment was used to establish a cellular I/R model in HT22 neurons, and lentiviral interference vector against Usf2 (LV-sh-Usf2) was used to infect the neurons. Our results showed that Usf2 was significantly upregulated in OGD/R-treated HT22 neurons that displayed an increased level in cell apoptosis and decreased levels in cell viability and autophagy, and interference of Usf2 largely rescued the effects of OGD/R on cell viability, apoptosis, and autophagy, suggesting an important role of Usf2 in neuron autophagy. In the mechanism exploration, we found that, as a transcription factor, Usf2 bound to the promoter of YTHDF1, a famous reader of N6-Methyladenosine (m6A), also induced by OGD/R, and promoted its transcription. Overexpression of YTHDF1 was able to reverse the improvement of Usf2 interference on viability and autophagy of HT22 neurons. Moreover, YTHDF1 suppressed autophagy to induce HT22 cell apoptosis through increasing m6A-mediated stability of Cdc25A, a newly identified autophagy inhibitor. Finally, we demonstrated that interference of Usf2 markedly improved autophagy and alleviated I/R-induced injury in MCAO mice.

Insulin-like Growth Factor II mRNA-Binding Protein 1 Regulates Pancreatic Cancer Cell Growth through the Surveillance of CDC25A mRNA.

A number of data indicate that the sources of different kinds of PDAC may be discovered at the transcription/transduction stage. RNA metabolism is manipulated at various steps by different RNA-binding proteins (RBPs), and the deregulation or irregular activity of RBPs is known to contribute to tumor promotion and progression. The insulin-like growth factor 2 mRNA-binding protein family (IMPs), and IMP1 in particular, has been linked with a poor prognosis in PDAC patients; however, little is known about its contribution in PDAC carcinogenesis. In this study, we investigated the function of IMP1 in PDAC. To evaluate IMP1 expression and correlation with PDAC prognosis, we utilized several public databases. Using a specific siRNA IMP1, we analyzed cell death and cell cycle progression in PDAC cell lines and 3D spheroids. The role of IMP1 was also evaluated in vivo in a Panc-1-derived tumor xenograft murine model. Public data suggest that PDAC patients with higher expression of IMP1 showed poor overall and progression-free survival. IMP1 silencing leads to reduced cell growth in PDAC cells and three-dimensional spheroids. Abrogation of IMP1 in PDAC cells showed lower levels of CDC25A, increased phosphorylation of the cyclin-dependent kinase (CDK)2, and accumulation of PDAC cells in the G1 phase. Immunoprecipitation experiments revealed that IMP1 binds CDC25A mRNA, thus controlling cell-cycle progression. Ultimately, we proved that suppression of IMP1 blocked in vivo growth of Panc-1 transferred into immunodeficient mice. Our results indicate that IMP1 drives the PDCA cell cycle and represents a novel strategy for overcoming PDCA cell proliferation.

CHK1-CDC25A-CDK1 regulate cell cycle progression and protect genome integrity in early mouse embryos.

After fertilization, remodeling of the oocyte and sperm genomes is essential to convert these highly differentiated and transcriptionally quiescent cells into early cleavage-stage blastomeres that are transcriptionally active and totipotent. This developmental transition is accompanied by cell cycle adaptation, such as lengthening or shortening of the gap phases G1 and G2. However, regulation of these cell cycle changes is poorly understood, especially in mammals. Checkpoint kinase 1 (CHK1) is a protein kinase that regulates cell cycle progression in somatic cells. Here, we show that CHK1 regulates cell cycle progression in early mouse embryos by restraining CDK1 kinase activity due to CDC25A phosphatase degradation. CHK1 kinase also ensures the long G2 phase needed for genome activation and reprogramming gene expression in two-cell stage mouse embryos. Finally, Chk1 depletion leads to DNA damage and chromosome segregation errors that result in aneuploidy and infertility.

Inherited CHEK2 p.H371Y mutation in solitary rectal ulcer syndrome among familial patients: A case report.

BACKGROUND: Solitary rectal ulcer syndrome (SRUS) is a rare rectal disease with unknown etiology. Data on the genetic background in SRUS is lacking. CASE SUMMARY: Here, we report the first case of SRUS in a mother-son relationship. Gene sequencing was conducted on the whole family, which revealed an inherited CHEK2 p.H371Y mutation. The experiment preliminarily revealed that the CHEK2 mutation did not affect the expression of CHEK2 protein, but affected the function of CHEK2, resulting in the expression level changes of downstream genes such as CDC25A. CONCLUSION: SRUS is a genetic susceptibility disease where CHEK2 p.H371Y mutation may play a crucial role in the development and prognosis of SRUS.

CircCCL22 Regulates CDC25A via Sponging miR-543 and Promotes Proliferation and Metastasis in Endometrial Cancer.

Endometrial cancer (EC) is the most common gynecological tumor. Circular RNAs are a novel type of non-coding RNA that have important regulatory functions, particularly in the pathogenic progression of cancer. In this study, we investigated the function of circCCL22, and elucidated its molecular mechanism in EC progresssion. The expression of circCCL22, miR-543 and CDC25A in EC tissues and cells were determined by qRT-PCR and western blot. Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, wound healing and transwell assays were executed to assess the cell viability, proliferation, migration and invasion. Dual-luciferase report assay was utilized to investigate the interaction of miR-543 with circCCL22 and CDC25A. The role of circCCL22 in EC in vivo was investigated by xenograft assay. CircCCL22 was notably upregulated in EC tissues and cells. Functionally, circCCL22 knockdown suppressed EC cell proliferation, migration and invasion in vitro, and inhibited tumor growth in vivo. Mechanistically, circCCL22 acted as "miR-543 sponges" to regulate its targeted gene CDC25A expression in EC cells. The inhibiting effect induced by circCCL22 knockdown on EC cell proliferation, migration and invasion was greatly reversed by miR-543 inhibition or CDC25A overexpression. Our results revealed that circCCL22 regulated EC progression through targeting miR-543/CDC25A axis, and it could be a novel therapeutic target of EC.

Metronomic dosing of ovarian cancer cells with the ATR inhibitor AZD6738 leads to loss of CDC25A expression and resistance to ATRi treatment.

OBJECTIVE: ATR kinase inhibitors promote cell killing by inducing replication stress and through potentiation of genotoxic agents in gynecologic cancer cells. To explore mechanisms of acquired resistance to ATRi in ovarian cancer, we characterized ATRi-resistant ovarian cancer cells generated by metronomic dosing with the clinical ATR inhibitor AZD6738. METHODS: ATRi-resistant ovarian cancer cells (OVCAR3 and OV90) were generated by dosing with AZD6738 and assessed for sensitivity to Chk1i (LY2603618), PARPi (Olaparib) and combination with cisplatin or a CDK4/6 inhibitor (Palbociclib). Models were characterized by diverse methods including silencing CDC25A in OV90 cells and assessing impact on ATRi response. Serum proteomic analysis of ATRi-resistant OV90 xenografts was performed to identify circulating biomarker candidates of ATRi-resistance. RESULTS: AZD6738-resistant cell lines are refractory to LY2603618, but not to Olaparib or combinations with cisplatin. Cell cycle analyses showed ATRi-resistant cells exhibit G1/S arrest following AZD6738 treatment. Accordingly, combination with Palbociclib confers resistance to AZD6738. AZD6738-resistant cells exhibit altered abundances of G1/S phase regulatory proteins, including loss of CDC25A in AZD6738-resistant OV90 cells. Silencing of CDC25A in OV90 cells confers resistance to AZD6738. Serum proteomics from AZD6738-resistant OV90 xenografts identified Vitamin D-Binding Protein (GC), Apolipoprotein E (APOE) and A1 (APOA1) as significantly elevated in AZD6738-resistant backgrounds. CONCLUSIONS: We show that metronomic dosing of ovarian cancer cells with AZD6738 results in resistance to ATR/ Chk1 inhibitors, that loss of CDC25A expression represents a mechanism of resistance to ATRi treatment in ovarian cancer cells and identify several circulating biomarker candidates of CDC25A low, AZD6738-resistant ovarian cancer cells.

Zinc-finger protein 382 antagonises CDC25A and ZEB1 signaling pathway in breast cancer.

Our previous studies found that Zinc-finger protein 382 (ZNF382) played as a tumor suppressor gene in esophageal and gastric cancers, and a positive correlation between the high expression of ZNF382 and better outcome in breast cancer patients. However, the biological roles and mechanisms of ZNF382 in breast cancer remains unclear. We detected ZNF382 expression by reverse-transcription PCR (RT-PCR) and real-time quantitative PCR (qRT-PCR) in breast cancer cells and tissues, and explored the impacts and mechanisms of ectopic ZNF382 expression in breast cancer cells in vitro and in vivo, respectively. Our results revealed that ZNF382 was significantly down-regulated in breast cancer tissues compared with adjacent non-cancer tissues. Restoration of ZNF382 expression in silenced breast cancer cells not only inhibited tumor cell colony formation, viability, migration and invasion, and epithelial-mesenchymal-transition (EMT), but also induced apoptosis and G0/G1 arrest. In conclusion, ZNF382 could induce G0/G1 cell cycle arrest through inhibiting CDC25A signaling, and, inhibit cell migration, invasion and EMT by antagonizing ZEB1 signaling in breast cancer cells.

Zanthoxylum bungeanum seed oil inhibits tumorigenesis of human melanoma A375 by regulating CDC25A/CyclinB1/CDK1 signaling pathways in vitro and in vivo.

Background: Zanthoxylum bungeanum seed oil (ZBSO) is extracted from the seeds of the traditional Chinese medicine Z. bungeanum Maxim, which has been shown to have anti-melanoma effects. However, the specific mechanisms are not illustrated adequately. Aims: To further investigate the mechanism by which ZBSO inhibits melanoma and to provide scientific evidence to support ZBSO as a potential melanoma therapeutic candidate. Methods: CCK-8 assays were used to detect the function of ZBSO on A375 cells. Based on transcriptomics analyses, Western blot analysis was applied to determine whether an association existed in ZBSO with the CDC25A/CyclinB1/CDK1 signaling pathway. In addition, RT-qPCR and immunohistochemistry analysis validated that ZBSO has the anti-melanoma effect in a nude mouse xenograft model of human melanoma. Then, 16S rRNA sequencing was used to detect the regulation of gut microbes. Results: Cellular assays revealed that ZBSO could inhibit A375 cell viability by regulating the cell cycle pathway. Further studies presented that ZBSO could constrain CDC25A/CyclinB1/CDK1 signaling pathway in vitro and in vivo models of melanoma. ZBSO did not produce toxicity in mice, and significantly reduced tumor volume in xenotransplants of A375 cells. Genome analysis indicated that ZBSO successfully altered specific gut microbes. Conclusion: ZBSO inhibited the growth of A375 cells by regulating CDC25A/cyclinB1/CDK1 signaling pathway both in vitro and in vivo, suggesting that ZBSO may be a novel potential therapeutic agent.

PLCε promotes the Warburg effect and tumorigenesis through AKT/GSK3ß/Cdc25a in bladder cancer.

Phospholipase C epsilon (PLCε) is a oncogene in various malignancies and regulates diverse cellular functions. But understanding of the relation between PLCε and glycolytic pathways has not been clearly identified. In the present study, we explored the effect of PLCε on the Warburg effect and tumorigenesis in bladder cancer (BCa). In our study, we showed that PLCε expression was elevated in BCa samples compared with matched adjacent nonmalignant bladder tissues. PLCε depletion using Lentivirus-shPLCε (LV-shPLCε) dramatically decreased cell growth, glucose consumption and lactate production, arresting T24 and BIU cells in the S phase of the cell cycle. We also observed that PLCε was correlated with the activation of protein kinase B (AKT) and cell division cycle 25 homolog A (Cdc25a) overexpression. In addition, we demonstrated that AKT/glycogen synthase kinase 3 beta (GSK3ß)/Cdc25a signaling pathways are involved in the PLCε-mediated Warburg effect in BCa. Moreover, we showed that PLCε had an effect on tumorigenesis in in vivo experiments. In summary, our findings demonstrate that AKT/GSK3ß/Cdc25a is critical for the effect PLCε on Warburg effect and tumorigenesis.

Molecular and Biological Investigation of Isolated Marine Fungal Metabolites as Anticancer Agents: A Multi-Target Approach.

Cancer is the leading cause of death globally, with an increasing number of cases being annually reported. Nature-derived metabolites have been widely studied for their potential programmed necrosis, cytotoxicity, and anti-proliferation leading to enrichment for the modern medicine, particularly within the last couple of decades. At a more rapid pace, the concept of multi-target agents has evolved from being an innovative approach into a regular drug development procedure for hampering the multi-fashioned pathophysiology and high-resistance nature of cancer cells. With the advent of the Red Sea Penicillium chrysogenum strain S003-isolated indole-based alkaloids, we thoroughly investigated the molecular aspects for three major metabolites: meleagrin (MEL), roquefortine C (ROC), and isoroquefortine C (ISO) against three cancer-associated biological targets Cdc-25A, PTP-1B, and c-Met kinase. The study presented, for the first time, the detailed molecular insights and near-physiological affinity for these marine indole alkaloids against the assign targets through molecular docking-coupled all-atom dynamic simulation analysis. Findings highlighted the superiority of MEL's binding affinity/stability being quite in concordance with the in vitro anticancer activity profile conducted via sulforhodamine B bioassay on different cancerous cell lines reaching down to low micromolar or even nanomolar potencies. The advent of lengthy structural topologies via the metabolites' extended tetracyclic cores and aromatic imidazole arm permitted multi-pocket accommodation addressing the selectivity concerns. Additionally, the presence decorating polar functionalities on the core hydrophobic tetracyclic ring contributed compound's pharmacodynamic preferentiality. Introducing ionizable functionality with more lipophilic characters was highlighted to improve binding affinities which was also in concordance with the conducted drug-likeness/pharmacokinetic profiling for obtaining a balanced pharmacokinetic/dynamic profile. Our study adds to the knowledge regarding drug development and optimization of marine-isolated indole-based alkaloids for future iterative synthesis and pre-clinical investigations as multi-target anticancer agents.

Let-7c-5p Represses Cisplatin Resistance of Lung Adenocarcinoma Cells by Targeting CDC25A.

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.

Dichloroacetate and vitamin C synergistically suppress proliferation, migration and invasion of glioma U87 and U251 cells / 中国药理学通报

Aim To investigate the effects of dichloroacetate(DCA)combined with vitamin C(VC)on the malignant behavior of glioma U87 and U251 cells, and to explore the potential mechanism. Methods U87 and U251 cells were treated with different concentrations of DCA alone or in combination with 5 mmol·L-1 VC. The proliferation rate of each group was detected by CCK-8 method and the cooperative index was calculated. U87 and U251 cells were treated with DMSO, 15 mmol·L-1 DCA, 5 mmol·L-1 VC and their combination. The changes of clonal formation, reactive oxygen species content, apoptosis, cell cycle, migration and invasion were detected via in vitro experiments, while the proliferation of U251 cells in vivo in each group was detected by subcutaneous tumor-forming model. Western blot was used to detect the expression levels and degradation rates of BCL2A1 and CDC25A in each group of cells after network pharmacological analysis of DCA and VC targets and their value in glioma, and the expression levels of CDK4, CDK6, cytochrome C, caspase-7 and cleaved-caspase-7 were detected. Results The combined index of 15 mmol·L-1 DCA and 5 mmol·L-1 VC was the highest. Compared with the control and single drug groups, the clonal formation, migration and invasion ability of cells in combination group in vitro significantly decreased, the proliferation rate in vivo also decreased, and the content of reactive oxygen species, apoptosis rate and G1 phase arrest rate significantly increased. BCL2A1 and CDC25A proteins were important targets of DCA and VC in glioma. Compared with the control and single-drug groups, the expression levels of BCL2A1, CDC25A, CDK4, and CDK6 in the combination group were significantly reduced, and the expression levels of cytochrome C and cleaved-caspase-7 markedly increased, and the protein degradation rates of BCL2A1 and CDC25A significantly increased in the combination group. Conclusions VC can cooperate with DCA to promote the degradation of BCL2A1 and CDC25A, and inhibit the malignant behavior of glioma cells.

SRSF10 stabilizes CDC25A by triggering exon 6 skipping to promote hepatocarcinogenesis.

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.

CircFNDC3B knockdown restrains the progression of oesophageal squamous cell carcinoma through miR-214-3p/CDC25A axis.

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.

BPTF inhibition antagonizes colorectal cancer progression by transcriptionally inactivating Cdc25A.

As the largest subunit of the nuclear remodeling factor complex, Bromodomain PHD Finger Transcription Factor (BPTF) has been reported to be involved in tumorigenesis and development in several cancers. However, to date, its functions and related molecular mechanisms in colorectal cancer (CRC) are still poorly defined and deserve to be revealed. In this study, we uncovered that, under the expression regulation of c-Myc, BPTF promoted CRC progression by targeting Cdc25A. BPTF was found to be highly expressed in CRC and promoted the proliferation and metastasis of CRC cells through BPTF specific siRNAs, shRNAs or inhibitors. Based on RNA-seq, combined with DNA-pulldown, ChIP and luciferase reporter assay, we proved that, by binding to -178/+107 region within Cdc25A promoter, BPTF transcriptionally activated Cdc25A, thus accelerating the cell cycle process of CRC cells. Meanwhile, BPTF itself was found to be transcriptionally regulated by c-Myc. Moreover, BPTF knockdown or inactivation was verified to sensitize CRC cells to chemotherapeutics, 5-Fluorouracil (5FU) and Oxaliplatin (Oxa), c-Myc inhibitor and cell cycle inhibitor not just at the cellular level in vitro, but in subcutaneous xenografts or AOM/DSS-induced in situ models of CRC in mice, while Cdc25A overexpression partially reversed BPTF silencing-caused tumor growth inhibition. Clinically, BPTF, c-Myc and Cdc25A were highly expressed in CRC tissues simultaneously, the expression of any two of the three was positively correlated, and their expressions were highly relevant to tumor differentiation, TNM staging and poor prognosis of CRC patients. Thus, our study indicated that the targeted inhibition of BPTF alone, or together with chemotherapy and/or cell cycle-targeted therapy, might act as a promising new strategy for CRC treatment, while c-Myc/BPTF/Cdc25A signaling axis is expected to be developed as an associated set of candidate biomarkers for CRC diagnosis and prognosis prediction.

F-Box Protein 11 Suppresses Cell Proliferation and Aerobic Glycolysis in Glioblastomas by Mediating the Ubiquitin Degradation of Cdc25A.

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.