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.

BUB1, BUB1B, CCNA2, and CDCA8, along with miR-524-5p, as clinically relevant biomarkers for the diagnosis and treatment of endometrial carcinoma.

BACKGROUND: Endometrial carcinoma (EC) is a malignant tumor of the female reproductive tract that has been associated with increased morbidity and mortality. This study aimed to identify biomarkers and potential therapeutic targets for EC. METHODS: A publicly available transcriptome data set comprising 587 EC cases was subjected to a comprehensive bioinformatics analysis to identify candidate genes responsible for EC occurrence and development. Next, we used clinical samples and cell experiments for validation. RESULTS: A total of 1,617 differentially expressed genes (DEGs) were identified. Analysis of patient survival outcomes revealed that BUB1, BUB1B, CCNA2, and CDCA8 were correlated with prognosis in patients with EC. Moreover, assessment of clinical samples confirmed that BUB1, BUB1B, CCNA2 and CDCA8 were strongly expressed in EC tissues. Additionally, bioinformatics and luciferase reporter assays confirmed that miR-524-5p can target and regulate these four genes. Overexpression of miR-524-5p significantly inhibited EC Ishikawa cells viability, migration and invasion. Inhibition of miR-524-5p showed the opposite results. CONCLUSIONS: Expression of miR-524-5p reduced the migration and invasion of Ishikawa EC cells, and decreased BUB1, BUB1B, CCNA2, and CDCA8 expression. miR-524-5p, as well as BUB1, BUB1B, CCNA2, and CDCA8, may be clinically relevant biomarkers for the diagnosis and treatment of EC.

DPY30 Promotes Proliferation and Cell Cycle Progression of Colorectal Cancer Cells via Mediating H3K4 Trimethylation.

DPY30, a core subunit of the SET1/MLL histone H3K4 methyltransferase complexes, plays an important role in diverse biological functions through the epigenetic regulation of gene transcription, especially in cancer development. However, its involvement in human colorectal carcinoma (CRC) has not been elucidated yet. Here we demonstrated that DPY30 was overexpressed in CRC tissues, and significantly associated with pathological grading, tumor size, TNM stage, and tumor location. Furthermore, DPY30 knockdown remarkably suppressed the CRC cell proliferation through downregulation of PCNA and Ki67 in vitro and in vivo, simultaneously induced cell cycle arrest at S phase by downregulating Cyclin A2. In the mechanistic study, RNA-Seq analysis revealed that enriched gene ontology of cell proliferation and cell growth was significantly affected. And ChIP result indicated that DPY30 knockdown inhibited H3 lysine 4 trimethylation (H3K4me3) and attenuated interactions between H3K4me3 with PCNA, Ki67 and cyclin A2 respectively, which led to the decrease of H3K4me3 establishment on their promoter regions. Taken together, our results demonstrate overexpression of DPY30 promotes CRC cell proliferation and cell cycle progression by facilitating the transcription of PCNA, Ki67 and cyclin A2 via mediating H3K4me3. It suggests that DPY30 may serve as a potential therapeutic molecular target for CRC.

Identification and Validation of Cyclin A2 and Cyclin E2 as Potential Biomarkers in Small Cell Lung Cancer.

INTRODUCTION: Small cell lung cancer (SCLC) is a special type of lung cancer sensitive to radiotherapy and chemotherapy but is prone to drug resistance and recurrence and has a very poor prognosis. This study aimed to explore the potential biomarkers and therapeutic targets for SCLC. METHODS: After batch normalization of GSE40275, GSE1037, and GSE44447 datasets, R was used to screen SCLC's differentially expressed genes (DEGs) and hub genes. We used immunohistochemistry (IHC) to assess the tissue's expression level of the hub gene. The clinical value of the hub gene was further evaluated based on the collected clinical-pathological data. RESULTS: In this study, a total of 230 DEGs (133 upregulated and 97 downregulated) were screened by the R package. The IHC showed that the expression of CCNA2 and CCNE2 in SCLC tissues was significantly higher than that in normal tissues (p < 0.01). Overexpression of CCNA2 was closely associated with the extensive period of NCCN (p = 0.004), tumor position (p = 0.046), and clinical stage (p = 0.002). The high expression levels of CCNE2 were related to high survival in chemotherapy patients (p = 0.019). CONCLUSION: CCNA2 and CCNE2 may serve as potential biomarkers of diagnosis and treatment for SCLC.

Identification of prognostic genes for early basal-like breast cancer with weighted gene co-expression network analysis.

BACKGROUND: Breast cancer (BC) has become the leading cause of death for women's malignancies and increasingly threatens the health of women worldwide. However, there is a lack of effective targeted drugs for basal-like BC. Therefore, biomarkers related to the prognosis of early BC need to be identified. METHODS: The RNA-seq data of 87 cases of early basal-like BC and 111 cases of normal breast tissue from The Cancer Genome Atlas were explored by the weighted gene co-expression network analysis method and Limma package. Then, intersected genes were identified, and hub genes were selected by the maximal clique centrality method. The prognostic effect of the hub genes was also evaluated in early basal-like BC. RESULTS: In total, 601 IGs were identified in this study. An APPI network was constructed, and the top 10 hub genes were selected, namely, cyclin B1, cyclin A2, cyclin-dependent kinase 1, cell division cycle 20, DNA topoisomerase II alpha, BUB1 mitotic checkpoint serine/threonine kinase, aurora kinase B (AURKB), cyclin B2, kinesin family member 11, and assembly factor for spindle microtubules. Only AURKB was found to be significantly associated with the overall prognosis of early basal-like BC. The immune cell infiltration analysis showed that the infiltration numbers of CD4 + T cells and naïve CD8 + T cells were positively correlated with the AURKB expression level, while those of naïve B cells and macrophage M2 cells were negatively correlated with the AURKB expression level in basal-like BC. CONCLUSION: AURKB might be a potential prognostic indicator in early basal-like BC.

Coevolution of HTLV-1-HBZ, Tax, and proviral load with host IRF-1 and CCNA-2 in HAM/TSP patients.

Background HTLV-1-associated myelopathy (HAM/TSP) is a progressive neurodegenerative inflammatory condition of HTLV-1 infection. Viral-host interactions are a significant contributor to the symptoms of HTLV-1-associated diseases. Therefore, in this study, the expression of the main regulatory viral factors and proviral load (PVL) and two host transcription molecules were evaluated in HAM/TSP patients. Materials and methods The study population included 17 HAM/TSP patients, 20 asymptomatic carriers (ACs), and 19 healthy controls (HCs). RNA and DNA were extracted from PBMCs for assessment of the gene expressions and PVL assessment using RT-qPCR and TaqMan method. Results HTLV-1-PVL was higher in HAM/TSPs (395.80 ± 99.69) than ACs (92.92 ± 29.41) (P = 0.001). The Tax expression in HAM/TSPs (7.8 ± 5.7) was strongly higher than ACs (0.06 ± 0.04) (P = 0.02), while HTLV-1-HBZ was only increased around three times in HAM/TSPs (3.17), compared to ACs (1.20) and not significant. The host IRF1 expression in HAM/TSPs (0.4 ± 0.31) was higher than ACs (0.09 ± 0.05) (P = 0.02) and also HCs (0.16 ± 0.07) (P = 0.5), but lower in ACs than HCs (p = 0.01). Although, in HAM/TSPs (0.13 ± 0.09) and ACs (0.03 ± 0.02) CCNA-2 expression was statistically fewer than HCs (0.18 ± 0.06) (P = 0.03, P = 0.001, respectively), in HAM/TSP was higher than ACs (P = 0.1), but did not meet a 95% confidence interval. Conclusion The study showed that HTLV-1-PVL and Tax, along with host IRF-1, could be considered biomarkers in HAM/TSP development. Furthermore, IRF-1, as an essential transcription factor, can be considered a pivotal target in HAM/TSPs treatment.

CCNA2 as an Immunological Biomarker Encompassing Tumor Microenvironment and Therapeutic Response in Multiple Cancer Types.

Background: Cancer is a major threat to human health worldwide. Although recent innovations and advances in early detection and effective therapies such as targeted drugs and immune checkpoint inhibitors have saved more lives of cancer patients and improved their quality of life, our knowledge about cancer remains largely unknown. CCNA2 belongs to the cell cyclin family and has been demonstrated to be a tumorigenic gene in multiple solid tumor types. The aim of the present study was to make a comprehensive analysis on the role of CCNA2 at a pancancer level. Methods: Multidatabases were collected to evaluate the different expression, prognostic value, DNA methylation, tumor mutation burden, microsatellite instability, mismatch repair, tumor immune microenvironment, and drug sensitivity of CCNA2 across pancancer. IHC was utilized to validate the expression and prognostic value of CCNA2 in ccRCC patients from SMMU cohort. Results: CCNA2 was differentially expressed in most cancer types vs. normal tissues. CCNA2 may significantly influence the prognosis of multiple cancer types, especially clear cell renal cell carcinoma (ccRCC). CCNA2 was also frequently mutated in most cancer types. Notably, CCNA2 was significantly correlated with immune cell infiltration and immune checkpoint inhibitory genes. In addition, CCNA2 was also strongly related to drug resistance. Conclusion: CCNA2 may prove to be a new biomarker for prognostic prediction, tumor immunity assessment, and drug susceptibility evaluation in pancancer level, especially in ccRCC.

MCTS1 promotes laryngeal squamous cell carcinoma cell growth via enhancing LARP7 stability.

MCTS1 Re-Initiation and Release Factor (MCTS1) has been characterised as an oncoprotein in some cancers. In this study, we explored the expression of MCTS1 in laryngeal squamous cell carcinoma (LSCC) and its regulatory effects on the proliferation and cell-cycle progression of tumour cells, as well as the underlying mechanisms. The data from the Cancer Genome Atlas was used to analyse MCTS1 expression and its correlation with survival outcomes in LSCC patients. Subsequent in vitro cellular and molecular studies were performed based on representative LSCC cell lines. Results showed that the upregulation of MCTS1 in LSCC is linked to poor progression-free survival (PFS) and disease-specific survival (DSS). In TU177 and AMC-HN-8 cells, MCTS1 exerted positive regulations on cell viability, colony formation, cell cycle progression, and the expression of CDK1, CDK2, cyclin A2, and cyclin B1. Co-IP assay confirmed mutual interaction between MCTS1 and LARP7, mainly in the cytoplasm. Cycloheximide (CHX) chase and co-IP assay of ubiquitination showed that MCTS1 could increase LARP7 protein half-life and reduce its poly-ubiquitination. LARP7 overexpression enhanced the viability and colony formation of LSCC cells and also elevated the expression of CDK1, CDK2, cyclin A2, and cyclin B1. In addition, its overexpression partly reversed the negative influence of MCTS1 knockdown. In summary, this study confirmed that the expression of MCTS1 might be an indicator of unfavourable prognosis for patients with LSCC. Mechanically, it promotes LSCC cell viability and proliferation via interacting with LARP7 and reducing its proteasomal-mediated degradation.

Mollugin induced oxidative DNA damage via up-regulating ROS that caused cell cycle arrest in hepatoma cells.

Mollugin has been proven to have anti-tumor activity. However, its potential anti-tumor mechanism remains to be fully elaborated. Herein, we investigated the growth inhibition of HepG2 cells, as well as the anti-tumor effect of mollugin and its molecular mechanism on H22-tumor bearing mice. In vitro, mollugin was shown to have a strong inhibitory effect on HepG2 cells in a concentration-dependent manner. Mollugin induced S-phase arrest of HepG2 cells, and increased intracellular reactive oxygen species (ROS) levels. Comet assay demonstrated that mollugin induced DNA damage in HepG2 cells, as well as an increase in the expression of p-H2AX. In addition, mollugin induced changes in cyclin A2 and CDK2. However, the addition of antioxidant glutathione (GSH) was able to reverse the effect of mollugin. In vivo, mollugin significantly inhibited tumor growth and reduced the tendency of tumor volume growth in mice. The tumor cell density was found to be decreased in the administration group, and the content of ROS in the tumor tissue significantly increased. The expression of p-H2AX, cyclin A2 and CDK2 were consistent with in vitro results. Mollugin demonstrated anti-hepatocellular carcinoma activity in vitro and in vivo, and its anti-hepatocellular carcinoma activity was found to be related to DNA damage and cell cycle arrest induced by excessive ROS production in cells.

Inducible expression of Oct-3/4 reveals synergy with Klf4 in targeting Cyclin A2 to enhance proliferation during early reprogramming.

During reprogramming of somatic cells, heightened proliferation is one of the earliest changes observed. While other early events such as mesenchymal-to-epithelial transition have been well studied, the mechanisms by which the cell cycle switches from a slow cycling state to a faster cycling state are still incompletely understood. To investigate the role of Oct-3/4 in this early transition, we created a 4-Hydroxytamoxifen (OHT) dependent Oct-3/4 Estrogen Receptor fusion (OctER). We confirmed that OctER can substitute for Oct-3/4 to reprogram mouse embryonic fibroblasts to a pluripotent state. During the early stages of reprograming, Oct-3/4 and Klf4 individually did not affect cell proliferation but in combination hastened the cell cycle. Using OctER + Klf4, we found that proliferative enhancement is OHT dose-dependent, suggesting that OctER is the driver of this transition. We identified Cyclin A2 as a likely target of Oct-3/4 + Klf4. In mESC, Klf4 and Oct-3/4 bind ∼100bp upstream of Cyclin A2 CCRE, suggesting a potential regulatory role. Using inducible OctER, we show a dose-dependent induction of Cyclin A2 promoter-reporter activity. Taken together, our results suggest that Cyclin A2 is a key early target during reprogramming, and support the view that a rapid cell cycle assists the transition to pluripotency.

Screening of pyroptosis-related genes influencing the therapeutic effect of dehydroabietic acid in liver cancer and construction of a survival nomogram.

OBJECTIVE: This study aimed to screen pyroptosis-related genes influencing the therapeutic effect of dehydroabietic acid in liver cancer and to construct an effective survival prognostic nomogram model. METHODS: Differentially expressed genes (DEGs) between liver cancer tissues and normal tissues were analyzed with The Cancer Genome Atlas database, weighted gene coexpression network analysis and a genetic expression compilation database. The targets of dehydroabietic acid were screened with databases such as TCMSP and pharmacy. Spearman correlation analysis was analyzed. The prognosis model was built through one-factor Cox analysis and LASSO regression. The final core targets were screened by prognosis-related genes combined with a protein-protein interaction (PPI) network. On this basis, the survival nomogram was constructed. The effects of different concentrations of dehydroabietic acid on the growth of HepG2 liver cancer cells were detected by CCK8. Moreover, the expression of related genes was further verified through real-time fluorescence quantitative PCR and Western blot. RESULTS: Venn diagram analysis of DEGs of liver cancer in three databases was performed, through which 890 genes related to the genesis and development of liver cancer were acquired. According to Venn diagram analysis of targets of dehydroabietic acid and related genes of liver cancer, 44 intersecting targets for liver cancer treatment with dehydroabietic acid were acquired. Then, 7 prognosis-related genes were identified through one-factor Cox analysis and LASSO regression of 25 related genes. Next, 10 targets were screened through the PPI network, and the intersection was processed, thus obtaining 3 ultimate core targets of KIF11, CCNA2 and CDC25A. The IC50 of dehydroabietic acid is 23.22 ± 0.98 µg/mL. According to further verification of related genes, the mRNA and protein levels of KIF11, CCNA2 and CDC25A decrease significantly after treatment with dehydroabietic acid. The nomogram shows that T stage is an independent risk factor, and the postoperative survival C-index of the model group was 0.709. CONCLUSIONS: Three pyroptosis-related genes that influence the therapeutic effect of dehydroabietic acid in liver cancer were screened through bioinformatics methods. The survival prognostic nomogram model, which is built based on independent risk factors that influence the postoperative survival of patients in the T stage, has good accuracy and can provide references for clinical and fundamental studies in the future.

Structural and functional characterization explains loss of dNTPase activity of the cancer-specific R366C/H mutant SAMHD1 proteins.

Elevated intracellular levels of dNTPs have been shown to be a biochemical marker of cancer cells. Recently, a series of mutations in the multifunctional dNTP triphosphohydrolase (dNTPase), sterile alpha motif and histidine-aspartate domain-containing protein 1 (SAMHD1), have been reported in various cancers. Here, we investigated the structure and functions of SAMHD1 R366C/H mutants, found in colon cancer and leukemia. Unlike many other cancer-specific mutations, the SAMHD1 R366 mutations do not alter cellular protein levels of the enzyme. However, R366C/H mutant proteins exhibit a loss of dNTPase activity, and their X-ray structures demonstrate the absence of dGTP substrate in their active site, likely because of a loss of interaction with the γ-phosphate of the substrate. The R366C/H mutants failed to reduce intracellular dNTP levels and restrict HIV-1 replication, functions of SAMHD1 that are dependent on the ability of the enzyme to hydrolyze dNTPs. However, these mutants retain dNTPase-independent functions, including mediating dsDNA break repair, interacting with CtIP and cyclin A2, and suppressing innate immune responses. Finally, SAMHD1 degradation in human primary-activated/dividing CD4+ T cells further elevates cellular dNTP levels. This study suggests that the loss of SAMHD1 dNTPase activity induced by R366 mutations can mechanistically contribute to the elevated dNTP levels commonly found in cancer cells.

Long non-coding RNAs HERH-1 and HERH-4 facilitate cyclin A2 expression and accelerate cell cycle progression in advanced hepatocellular carcinoma.

BACKGROUND: The advanced hepatocellular carcinoma (HCC), such as the recurrent tumor after liver transplantation (LT), is an obstacle of HCC treatment. The aim of this study was to discover the underlying mechanism of HCC progression caused by non-coding RNAs (ncRNAs). METHODS: To this end, we investigated the selected patient cohort of matching primary and recurrent HCC after receiving LT. The recurrent tumors after LT were regarded as clinical models of the advanced HCC. Microarrays were used to profile lncRNA and mRNA expression in HCC recurrent and primary tissue samples. The mRNA profile characteristics were analyzed by bioinformatics. Two cell lines, HepG2 and QGY-7703, were used as HCC cell models. The protein-coding potential, length, and subcellular location of the interested lncRNAs were examined by bioinformatics, Northern blot, fluorescent in situ hybridization (FISH), and quantitative RT-PCR (qRT-PCR) assays. HCC cell proliferation was detected by CCK-8, doubling time and proliferation marker gene quantitation assays. DNA replication during the cell cycle was measured by EdU/PI staining and flow cytometry analyses. Promoter activity was measured using a luciferase reporter assay. Interactions between DNA, RNA, and protein were examined by immunoprecipitation and pull-down assays. The miRNA-target regulation was validated by a fluorescent reporter assay. RESULTS: Both lncRNA and mRNA profiles exhibited characteristic alterations in the recurrent tumor cells compared with the primary HCC. The mRNA profile in the HCC recurrent tissues, which served as model of advanced HCC, showed an aberrant cell cycle regulation. Two lncRNAs, the highly expressed lncRNA in recurrent HCC (HERH)-1 and HERH-4, were upregulated in the advanced HCC cells. HERH-1/4 enhanced proliferation and promoted DNA replication and G1-S transition during the cell cycle in HCC cells. HERH-1 interacted with the transcription factor CREB1. CREB1 enhanced cyclin A2 (CCNA2) transcription, depending on HERH-1-CREB1 interaction. HERH-4 acted as an miR-29b/c sponge to facilitate CCNA2 protein translation through a competing endogenous RNA (ceRNA) pathway. CONCLUSIONS: The oncogenic lncRNA HERH-1/4 promoted CCNA2 expression at the transcriptional and post-transcriptional levels and accelerated cell cycle progression in HCC cells. The HERH-1-CREB1-CCNA2 and HERH-4-miR-29b/c-CCNA2 axes served as molecular stimuli for HCC advance.

The Conditional Knockout Analogous System: CRISPR-Mediated Knockout Together with Inducible Degron and Transcription-Controlled Expression.

The revolutionary CRISPR technology opens a new era of cell biology in mammalian cells. The InDel mutation is induced by CRISPR and results in the frameshift mutation of the gene. Owing to the nature of CRISPR induced knockout, the conditional knockout using CRISPR technology is not common. With the recent development of the small molecule-inducible degron system, an analogous system to the classical genetic conditional knockout has become feasible. By integrating CRISPR-knockout, the tetracycline-controlled transcriptional and auxin-induced degradation post-translational control of protein expression, a method imitating the conditional knockout is developed. We herein describe the detailed protocol for the generation of a conditional protein inactivation in human cancer cells. The system is especially useful to study essential gene function in aneuploidy cancer cells where gain in copy number is common.

Phosphorylation of human phospholipase A1 DDHD1 at newly identified phosphosites affects its subcellular localization.

Phospholipase A1 (PLA1) hydrolyzes the fatty acids of glycerophospholipids, which are structural components of the cellular membrane. Genetic mutations in DDHD1, an intracellular PLA1, result in hereditary spastic paraplegia (HSP) in humans. However, the regulation of DDHD1 activity has not yet been elucidated in detail. In the present study, we examined the phosphorylation of DDHD1 and identified the responsible protein kinases. We performed MALDI-TOF MS/MS analysis and Phos-tag SDS-PAGE in alanine-substitution mutants in HEK293 cells and revealed multiple phosphorylation sites in human DDHD1, primarily Ser8, Ser11, Ser723, and Ser727. The treatment of cells with a protein phosphatase inhibitor induced the hyperphosphorylation of DDHD1, suggesting that multisite phosphorylation occurred not only at these major, but also at minor sites. Site-specific kinase-substrate prediction algorithms and in vitro kinase analyses indicated that cyclin-dependent kinase CDK1/cyclin A2 phosphorylated Ser8, Ser11, and Ser727 in DDHD1 with a preference for Ser11 and that CDK5/p35 also phosphorylated Ser11 and Ser727 with a preference for Ser11. In addition, casein kinase CK2α1 was found to phosphorylate Ser104, although this was not a major phosphorylation site in cultivated HEK293 cells. The evaluation of the effects of phosphorylation revealed that the phosphorylation mimic mutants S11/727E exhibit only 20% reduction in PLA1 activity. However, the phosphorylation mimics were mainly localized to focal adhesions, whereas the phosphorylation-resistant mutants S11/727A were not. This suggested that phosphorylation alters the subcellular localization of DDHD1 without greatly affecting its PLA1 activity.

Integrated analysis of ceRNA network in hepatocellular carcinoma using bioinformatics analysis.

BACKGROUND: Long noncoding RNAs (lncRNAs) can work as microRNA (miRNA) sponges through a competitive endogenous RNA (ceRNA) mechanism. LncRNAs and miRNAs are important components of competitive endogenous binding, and their expression imbalance in hepatocellular carcinoma (HCC) is closely related to tumor development, diagnosis, and prognosis. This study explored the potential impact of the ceRNA regulatory network in HCC on the prognosis of HCC patients. METHODS: We thoroughly researched the differential expression profiles of lncRNAs, miRNAs, and mRNAs from 2 HCC Gene Expression Omnibus datasets (GSE98269 and GSE60502). Then, a dysregulated ceRNA network was constructed by bioinformatics. In addition, hub genes in the ceRNA network were screened by Cytoscape, these hub genes functional analysis was performed by gene set enrichment analysis, and the expression of these hub genes in tumors and their correlation with patient prognosis were verified with Gene Expression Profiling Interactive Analysis. RESULTS: A ceRNA network was successfully constructed in this study including 4 differentially expressed (DE) lncRNAs, 7 DEmiRNAs, and 166 DEmRNAs. Importantly, 4 core genes (CCNA2, CHEK1, FOXM1, and MCM2) that were significantly associated with HCC prognosis were identified. CONCLUSIONS: Our study provides comprehensive and meaningful insights into HCC tumorigenesis and the underlying molecular mechanisms of ceRNA. Furthermore, the specific ceRNAs can be further used as potential therapeutic targets and prognostic biomarkers for HCC.

Bora phosphorylation substitutes in trans for T-loop phosphorylation in Aurora A to promote mitotic entry.

Polo-like kinase 1 (Plk1) is instrumental for mitotic entry and progression. Plk1 is activated by phosphorylation on a conserved residue Thr210 in its activation segment by the Aurora A kinase (AURKA), a reaction that critically requires the co-factor Bora phosphorylated by a CyclinA/B-Cdk1 kinase. Here we show that phospho-Bora is a direct activator of AURKA kinase activity. We localize the key determinants of phospho-Bora function to a 100 amino acid region encompassing two short Tpx2-like motifs and a phosphoSerine-Proline motif at Serine 112, through which Bora binds AURKA. The latter substitutes in trans for the Thr288 phospho-regulatory site of AURKA, which is essential for an active conformation of the kinase domain. We demonstrate the importance of these determinants for Bora function in mitotic entry both in Xenopus egg extracts and in human cells. Our findings unveil the activation mechanism of AURKA that is critical for mitotic entry.

Identification of LINC00665-miR-let-7b-CCNA2 competing endogenous RNA network associated with prognosis of lung adenocarcinoma.

Prognosis of patients with lung cancer remains extremely poor; thus, we sought to unearth novel competing endogenous RNA (ceRNA) networks associated with the prognosis of lung adenocarcinoma (LUAD). Aberrant mRNAs were identified from the intersection of three Gene Expression Omnibus (GEO) datasets. A protein-protein interaction (PPI) network was constructed, and miRNAs and long noncoding RNAs (lncRNAs) upstream of mRNAs were predicted. In the present study, 402 upregulated and 638 downregulated genes in lung cancer tissues were identified. Functional analysis showed significant enrichment of cancer pathways. In these top hub genes, 10 upregulated and 7 downregulated genes had substantial prognostic values in LUAD. Thirty-seven miRNAs were predicted to target 17 key genes, and only five miRNAs exhibited prognostic correlation. Through stepwise reverse prediction and validation from miRNA to lncRNA, four key lncRNAs were identified using expression and survival analysis. Ultimately, the co-expression analysis identified LINC00665-miR-let-7b-CCNA2 as the key ceRNA network associated with the prognosis of LUAD. We successfully constructed a novel ceRNA network wherein each component was significantly associated with the prognosis of LUAD. Hence, we propose that this network may provide key biomarkers or potential therapeutic targets for LUAD prognosis.

Proliferation tracing reveals regional hepatocyte generation in liver homeostasis and repair.

Organ homeostasis is orchestrated by time- and spatially restricted cell proliferation. Studies identifying cells with superior proliferative capacities often rely on the lineage tracing of a subset of cell populations, which introduces a potential selective bias. In this work, we developed a genetic system [proliferation tracer (ProTracer)] by incorporating dual recombinases to seamlessly record the proliferation events of entire cell populations over time in multiple organs. In the mouse liver, ProTracer revealed more hepatocyte proliferation in distinct zones during liver homeostasis, injury repair, and regrowth. Clonal analysis showed that most of the hepatocytes labeled by ProTracer had undergone cell division. By genetically recording proliferation events of entire cell populations, ProTracer enables the unbiased detection of specific cellular compartments with enhanced regenerative capacities.

Cyclin A2 localises in the cytoplasm at the S/G2 transition to activate PLK1.

Cyclin A2 is a key regulator of the cell cycle, implicated both in DNA replication and mitotic entry. Cyclin A2 participates in feedback loops that activate mitotic kinases in G2 phase, but why active Cyclin A2-CDK2 during the S phase does not trigger mitotic kinase activation remains unclear. Here, we describe a change in localisation of Cyclin A2 from being only nuclear to both nuclear and cytoplasmic at the S/G2 border. We find that Cyclin A2-CDK2 can activate the mitotic kinase PLK1 through phosphorylation of Bora, and that only cytoplasmic Cyclin A2 interacts with Bora and PLK1. Expression of predominately cytoplasmic Cyclin A2 or phospho-mimicking PLK1 T210D can partially rescue a G2 arrest caused by Cyclin A2 depletion. Cytoplasmic presence of Cyclin A2 is restricted by p21, in particular after DNA damage. Cyclin A2 chromatin association during DNA replication and additional mechanisms contribute to Cyclin A2 localisation change in the G2 phase. We find no evidence that such mechanisms involve G2 feedback loops and suggest that cytoplasmic appearance of Cyclin A2 at the S/G2 transition functions as a trigger for mitotic kinase activation.