Phosphorylation of CAP-G is required for its chromosomal DNA localization during mitosis

Important role and underlying mechanism of non‑SMC condensin I complex subunit G in tumours (Review)

At present, the incidence of tumours is increasing on a yearly basis, and tumourigenesis is usually associated with chromosomal instability and cell cycle dysregulation. Moreover, abnormalities in the chromosomal structure often lead to DNA damage, further exacerbating gene mutations and chromosomal rearrangements. However, the non‑SMC condensin I complex subunit G (NCAPG) of the structural maintenance of chromosomes family is known to exert a key role in tumour development. It has been shown that high expression of NCAPG is closely associated with tumour development and progression. Overexpression of NCAPG variously affects chromosome condensation and segregation during cell mitosis, influences cell cycle regulation, promotes tumour cell proliferation and invasion, and inhibits apoptosis. In addition, NCAPG has been associated with tumour cell stemness, tumour resistance and recurrence. The aim of the present review was to explore the underlying mechanisms of NCAPG during tumour development, with a view towards providing novel targets and strategies for tumour therapy, and through the elucidation of the mechanisms involved, to lay the foundation for future developments in health.

Involvement of langerin in the protective function of a keratan sulfate-based disaccharide in an emphysema mouse model

Chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis, is now the third cause of death worldwide, and COVID-19 infection has been reported as an exacerbation factor of them. In this study, we report that the intratracheal administration of the keratan sulfate-based disaccharide L4 mitigates the symptoms of elastase-induced emphysema in a mouse model. To know the molecular mechanisms, we performed a functional analysis of a C-type lectin receptor, langerin, a molecule that binds L4. Using mouse BMDCs (bone marrow-derived dendritic cells) as langerin-expressing cells, we observed the downregulation of IL-6 and TNFa and the upregulation of IL-10 after incubation with L4. We also identified CapG (a macrophage-capping protein) as a possible molecule that binds langerin by immunoprecipitation combined with a mass spectrometry analysis. We identified a portion of the CapG that was localized in the nucleus and binds to the promoter region of IL-6 and the TNFa gene in BMDCs, suggesting that CapG suppresses the gene expression of IL-6 and TNFa as an inhibitory transcriptional factor. To examine the effects of L4 in vivo, we also generated langerin-knockout mice by means of genome editing technology. In an emphysema mouse model, the administration of L4 did not mitigate the symptoms of emphysema as well as the inflammatory state of the lung in the langerin-knockout mice. These data suggest that the anti-inflammatory effect of L4 through the langerin-CapG axis represents a potential therapeutic target for the treatment of emphysema and COPD.

Targeting CDK1 in cancer: mechanisms and implications

Cyclin dependent kinases (CDKs) are serine/threonine kinases that are proposed as promising candidate targets for cancer treatment. These proteins complexed with cyclins play a critical role in cell cycle progression. Most CDKs demonstrate substantially higher expression in cancer tissues compared with normal tissues and, according to the TCGA database, correlate with survival rate in multiple cancer types. Deregulation of CDK1 has been shown to be closely associated with tumorigenesis. CDK1 activation plays a critical role in a wide range of cancer types; and CDK1 phosphorylation of its many substrates greatly influences their function in tumorigenesis. Enrichment of CDK1 interacting proteins with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis was conducted to demonstrate that the associated proteins participate in multiple oncogenic pathways. This abundance of evidence clearly supports CDK1 as a promising target for cancer therapy. A number of small molecules targeting CDK1 or multiple CDKs have been developed and evaluated in preclinical studies. Notably, some of these small molecules have also been subjected to human clinical trials. This review evaluates the mechanisms and implications of targeting CDK1 in tumorigenesis and cancer therapy.

NCAPG as a novel prognostic biomarker in numerous cancers: a meta-analysis and bioinformatics analysis

BACKGROUND

Identification of effective biomarkers for cancer prognosis is a primary research challenge. Recently, several studies have reported the relationship between NCAPG and the occurrence of various tumors. However, none have combined meta-analytical and bioinformatics approaches to systematically assess the role of NCAPG in cancer.

METHODS

We searched four databases, namely, PubMed, Web of Science, Embase, and the Cochrane Library, for relevant articles published before April 30, 2022. The overall hazard ratio or odds ratio and 95% confidence intervals were calculated to assess the relationship between NCAPG expression and cancer survival prognosis or clinical characteristics. Furthermore, the aforementioned results were validated using the GEPIA2, Kaplan-Meier plotter, and PrognoScan databases.

RESULTS

The meta-analysis included eight studies with 1096 samples. The results showed that upregulation of NCAPG was correlated with poorer overall survival (hazard ratio = 2.90, 95% confidence interval = 2.06-4.10, P < 0.001) in the cancers included in the study. Subgroup analysis showed that in some cancers, upregulation of NCAPG was correlated with age, distant metastasis, lymph node metastasis, TNM stage, relapse, differentiation, clinical stage, and vascular invasion. These results were validated using the GEPIA2, UALCAN, and PrognoScan databases. We also explored the processes of NCAPG methylation and phosphorylation.

CONCLUSION

Dysregulated NCAPG expression is associated with the clinical prognostic and pathological features of various cancers. Therefore, NCAPG can serve as a human cancer therapeutic target and a new potential prognostic biomarker.

Developing mRNA signatures as a novel prognostic biomarker predicting high risk multiple myeloma

Background

Multiple myeloma (MM) remains an essentially incurable disease. This study aimed to establish a predictive model for estimating prognosis in newly diagnosed MM based on gene expression profiles.

Methods

RNA-seq data were downloaded from the Multiple Myeloma Research Foundation (MMRF) CoMMpass Study and the Genotype-Tissue Expression (GTEx) databases. Weighted gene coexpression network analysis (WGCNA) and protein-protein interaction network analysis were performed to identify hub genes. Enrichment analysis was also conducted. Patients were randomly split into training (70%) and validation (30%) datasets to build a prognostic scoring model based on the least absolute shrinkage and selection operator (LASSO). CIBERSORT was applied to estimate the proportion of 22 immune cells in the microenvironment. Drug sensitivity was analyzed using the OncoPredict algorithm.

Results

A total of 860 newly diagnosed MM samples and 444 normal counterparts were screened as the datasets. WGCNA was applied to analyze the RNA-seq data of 1589 intersecting genes between differentially expressed genes and prognostic genes. The blue module in the PPI networks was analyzed with Cytoscape, and 10 hub genes were identified using the MCODE plug-in. A three-gene (TTK, GINS1, and NCAPG) prognostic model was constructed. This risk model showed remarkable prognostic value. CIBERSORT assessment revealed the risk model to be correlated with activated memory CD4 T cells, M0 macrophages, M1 macrophages, eosinophils, activated dendritic cells, and activated mast cells. Furthermore, based on OncoPredict, high-risk MM patients were sensitive to eight drugs.

Conclusions

We identified and constructed a three-gene-based prognostic model, which may provide new and in-depth insights into the treatment of MM patients.

Regulation of the mitotic chromosome folding machines

Over the last several years enormous progress has been made in identifying the molecular machines, including condensins and topoisomerases that fold mitotic chromosomes. The discovery that condensins generate chromatin loops through loop extrusion has revolutionized, and energized, the field of chromosome folding. To understand how these machines fold chromosomes with the appropriate dimensions, while disentangling sister chromatids, it needs to be determined how they are regulated and deployed. Here, we outline the current understanding of how these machines and factors are regulated through cell cycle dependent expression, chromatin localization, activation and inactivation through post-translational modifications, and through associations with each other, with other factors and with the chromatin template itself. There are still many open questions about how condensins and topoisomerases are regulated but given the pace of progress in the chromosome folding field, it seems likely that many of these will be answered in the years ahead.

Identification of the Key Genes Involved in the Tumorigenesis and Prognosis of Prostate Cancer

Background. Prostate cancer (PCa) is a malignant tumor in males, with a majority of the cases advancing to metastatic castration resistance. Metastasis is the leading cause of mortality in PCa. The traditional early detection and prediction approaches cannot differentiate between the different stages of PCa. Therefore, new biomarkers are necessary for early detection and clear differentiation of PCa stages to provide precise therapeutic intervention. Methods. The objective of the study was to find significant differences in genes and combine the three GEO datasets with TCGA-PRAD datasets (DEG). Weighted gene coexpression network analysis (WGCNA) determined the gene set and PCa clinical feature correlation module utilizing the TGGA-PRAD clinical feature data. The correlation module genes were rescreened using the biological information analysis tools, with the three hub genes (TOP2A, NCAPG, and BUB1B) for proper verification. Finally, internal (TCGA) and external (GSE32571, GSE70770) validation datasets were used to validate and predict the value of last hub genes. Results. The hub gene was abnormally upregulated in PCa samples during verification. The expression of each gene was favorably connected with the Gleason score and TN tumor grade in clinical samples but negatively correlated with the overall survival rate. The expression of these genes was linked to CD8 naive cells and macrophages, among other cells. Antitumor immune cells like NK and NKT were favorably and adversely correlated with infiltrating cells, respectively. Simultaneously, the GSCV and GSEA indicated that the hub gene is connected with cell proliferation, death, and androgen receptor, among other signaling pathways. Therefore, these genes could influence the incidence and progression of PCa by participating in or modulating various signaling pathways. Furthermore, using the online tool of CMap, we examined the individual medications for Hughes and determined that tipifarnib could be useful for the clinical therapy of PCa. Conclusion. TOP2A, NCAPG, and BUB1B are important genes intimately linked to the clinical prognosis of PCa and can be employed as reliable biomarkers for early diagnosis and prognosis. Moreover, these genes can provide a theoretical basis for precision differentiation and treatment of PCa.

Dephosphorylation in nuclear reassembly after mitosis

In most animal cell types, the interphase nucleus is largely disassembled during mitotic entry. The nuclear envelope breaks down and chromosomes are compacted into separated masses. Chromatin organization is also mostly lost and kinetochores assemble on centromeres. Mitotic protein kinases play several roles in inducing these transformations by phosphorylating multiple effector proteins. In many of these events, the mechanistic consequences of phosphorylation have been characterized. In comparison, how the nucleus reassembles at the end of mitosis is less well understood in mechanistic terms. In recent years, much progress has been made in deciphering how dephosphorylation of several effector proteins promotes nuclear envelope reassembly, chromosome decondensation, kinetochore disassembly and interphase chromatin organization. The precise roles of protein phosphatases in this process, in particular of the PP1 and PP2A groups, are emerging. Moreover, how these enzymes are temporally and spatially regulated to ensure that nuclear reassembly progresses in a coordinated manner has been partly uncovered. This review provides a global view of nuclear reassembly with a focus on the roles of dephosphorylation events. It also identifies important open questions and proposes hypotheses.

Female Germ Cell Development in Chickens and Humans: The Chicken Oocyte Enriched Genes Convergent and Divergent with the Human Oocyte

The development of germ cells and other physiological events in the differentiated ovary of humans are highly conserved with several mammalian species, except for the differences in timing. However, comparative knowledge on this topic is very scarce with respect to humans and lower vertebrates, such as chickens. In chickens, female germ cells enter into meiosis around embryonic day (E) 15.5 and are arrested in meiotic prophase I as primary oocytes. The oocytes arrested in meiosis I are accumulated in germ-cell cysts; shortly after hatching, they are enclosed by flattened granulosa cells in order to form primordial follicles. In humans, the process of meiotic recombination in female germ cells begins in the 10–11th week of gestation, and primordial follicles are formed at around week 20. In this review, we comprehensively elucidate both the conservation and the species-specific differences between chickens and humans with respect to germ cell, oocyte, and follicle development. Importantly, we provide functional insights into a set of chicken oocyte enriched genes (from E16 to 1 week post-hatch) that show convergent and divergent expression patterns with respect to the human oocyte (from week 11 to 26).

AC099850.3/NCAPG Axis Predicts Poor Prognosis and is Associated with Resistance to EGFR Tyrosine-Kinase Inhibitors in Lung Adenocarcinoma

Background

TKI-acquired resistance markedly interferes with treatment of lung cancer patients with EGFR mutant features. Long non-coding RNAs (lncRNAs) modify EGFR-TKI resistance during tumor progression. Non-structural maintenance of chromosomes condensin I complex subunit G (NCAPG) is a mitosis-related protein that is involved in tumorigenesis. We investigated the potential regulatory lncRNAs of NCAPG in lung adenocarcinoma (LUAD) and assessed their roles in EGFR-TKI resistance.

Methods

Data for 1678 lung cancer patients were retrieved from TCGA and GEO databases and used to evaluate NCAPG and lncRNAs expressions, as well as their prognostic significance in LUAD. Protein levels of NCAPG in LUAD were validated by immuno-histochemistry. To assess the relationship between NCAPG levels and EGFR-TKIs sensitivity, a cohort of 57 LUAD patients administered with EGFR-TKIs was used.

Results

Both NCAPG and lncRNA AC099850.3 were over-expressed in LUAD tissues, and correlated with tumor progression and poor prognosis in LUAD. LncRNA AC099850.3 was identified as a potential regulator of NCAPG expressions. The AC099850.3/NCAGP axis was markedly correlated with EGFR mutations and IC₅₀ of EGFR-TKIs. Besides, elevated NCAPG levels were associated with EGFR-TKIs resistance in 57 LUAD patients undergoing TKIs treatment. Gene set enrichment analysis revealed that both AC099850.3 and NCAGP were abundant in the cell cycle and the p53 signaling pathway.

Conclusion

The AC099850.3/NCAPG axis is a potential prognostic predictor and therapeutic biomarker for EGFR-TKIs in LUAD.

Identification of Potential Biomarkers for Pan-Cancer Diagnosis and Prognosis Through the Integration of Large-Scale Transcriptomic Data

Cancer is one of the leading causes of death worldwide, bringing a significant burden to human health and society. Accurate cancer diagnosis and biomarkers that can be used as robust therapeutic targets are of great importance as they facilitate early and effective therapies. Shared etiology among cancers suggests the existence of pan-cancer biomarkers, performance of which could benefit from the large sample size and the heterogeneity of the studied patients. In this study, we conducted a systematic RNA-seq study of 9,213 tumors and 723 para-cancerous tissue samples of 28 solid tumors from the Cancer Genome Atlas (TCGA) database, and 7,008 normal tissue samples from the Genotype-Tissue Expression (GTEx) database. By differential gene expression analysis, we identified 214 up-regulated and 186 downregulated differentially expressed genes (DEGs) in more than 80% of the studied tumors, respectively, and obtained 20 highly linked up- and downregulated hub genes from them. These markers have rarely been reported in multiple tumors simultaneously. We further constructed pan-cancer diagnostic models to classify tumors and para-cancerous tissues using 10 up-regulated hub genes with an AUC of 0.894. Survival analysis revealed that these hub genes were significantly associated with the overall survival of cancer patients. In addition, drug sensitivity predictions for these hub genes in a variety of tumors obtained several broad-spectrum anti-cancer drugs targeting pan-cancer. Furthermore, we predicted immunotherapy sensitivity for cancers based on tumor mutational burden (TMB) and the expression of immune checkpoint genes (ICGs), providing a theoretical basis for the treatment of tumors. In summary, we identified a set of biomarkers that were differentially expressed in multiple types of cancers, and these biomarkers can be potentially used for diagnosis and used as therapeutic targets.

NCAPG Promotes Tumor Progression and Modulates Immune Cell Infiltration in Glioma

Glioma is one of the most deadly types of brain cancer. As it is highly invasive, the prognosis for glioma patients remains dismal, with median survival rarely exceeding 16 months. Thus, developing a new prognostic biomarker for glioma and investigating its molecular mechanisms is necessary for the development of an efficient treatment strategy. In this study, we analyzed a cohort of 1,131 glioma patients using RNA-seq data from The Cancer Genome Atlas (TCGA project) and Gene Expression Omnibus (GSE4290 and GSE16011 datasets), and validated the results using the RNA-seq data of 1,018 gliomas from the Chinese Glioma Genome Atlas (CGGA project). We used the R language as the main tool for statistical analysis and data visualization. We found that NCAPG, a mitosis-associated chromosomal condensing protein, is highly expressed in glioma tissues. Furthermore, the expression of NCAPG increased significantly with the increase in tumor grade, and high NCAPG expression was found to be a predictor of poor overall survival in glioma patients (P < 0.001). This result shows that NCAPG expression could be an independent prognostic factor. Importantly, when the expression of NCAPG was knocked down, the CCK-8 assay revealed that the proliferation of glioma cells (LN-229 and T98G cell lines) decreased significantly compared with the control group. In addition, the healing rates of these cells were significantly lower in the si-NCAPG group than in the control group (P < 0.001). We then used the CIBERSORT algorithm to analyze the expression levels of 22 subpopulations of immune cells and found that NCAPG was significantly negatively correlated with natural killer cell activation. In addition, it was positively correlated with MHC-I molecules and ADAM17. Our study is first in comprehensively describing the high expression of NCAPG in glioma. It also shows that NCAPG can function as an independent prognostic predictor of glioma, and that targeting NCAPG can be a new strategy for the treatment of glioma patients.

Identification of UBE2I as a Novel Biomarker in ccRCC Based on a Large-Scale CRISPR-Cas9 Screening Database and Immunohistochemistry

Background: The genome-wide CRISPR-cas9 dropout screening has emerged as an outstanding approach for characterization of driver genes of tumor growth. The present study aims to investigate core genes related to clear cell renal cell carcinoma (ccRCC) cell viability by analyzing the CRISPR-cas9 screening database DepMap, which may provide a novel target in ccRCC therapy.

Methods: Candidate genes related to ccRCC cell viability by CRISPR-cas9 screening from DepMap and genes differentially expressed between ccRCC tissues and normal tissues from TCGA were overlapped. Weighted gene coexpression network analysis, pathway enrichment analysis, and protein–protein interaction network analysis were applied for the overlapped genes. The least absolute shrinkage and selection operator (LASSO) regression was used to construct a signature to predict the overall survival (OS) of ccRCC patients and validated in the International Cancer Genome Consortium (ICGC) and E-MTAB-1980 database. Core protein expression was determined using immunohistochemistry in 40 cases of ccRCC patients.

Results: A total of 485 essential genes in the DepMap database were identified and overlapped with differentially expressed genes in the TCGA database, which were enriched in the cell cycle pathway. A total of four genes, including UBE2I, NCAPG, NUP93, and TOP2A, were included in the gene signature based on LASSO regression. The high-risk score of ccRCC patients showed worse OS compared with these low-risk patients in the ICGC and E-MTAB-1980 validation cohort. UBE2I was screened out as a key gene. The immunohistochemistry indicated UBE2I protein was highly expressed in ccRCC tissues, and a high-level nuclear translocation of UBE2I occurs in ccRCC. Based on the area under the curve (AUC) values, nuclear UBE2I had the best diagnostic power (AUC = 1). Meanwhile, the knockdown of UBE2I can inhibit the proliferation of ccRCC cells.

Conclusion: UBE2I, identified by CRISPR-cas9 screening, was a core gene-regulating ccRCC cell viability, which accumulated in the nucleus and acted as a potential novel promising diagnostic biomarker for ccRCC patients. Blocking the nuclear translocation of UBE2I may have potential therapeutic value with ccRCC patients.

Inhibition of NCAPG expression inactivates the Wnt/β-catenin signal to suppresses endometrial cancer cell growth in vitro

Endometrial cancer (EC) ranks as the most prevalent malignancy occurring in the female genital tract. Non-SMC condensin I complex subunit G (NCAPG), a mitotic associated chromosomal condensing protein, is reported to be frequently abnormally expressed in several tumors and plays a vital role in carcinogenesis. Our study aimed to explore the effect of NCAPG on cell proliferation and apoptosis in EC cells and to determine the underlying mechanism. Expression and survival data of NCAPG in EC tissues were analyzed by bioinformatics methods. Cell proliferation was evaluated by EdU and CCK-8 assays. Apoptosis was assessed by flow cytometry analysis. Expression of NCAPG, proliferating cell nuclear antigen (PCNA), Ki67, Bcl-2, Bax, active caspase-3, active β-catenin, and c-Myc were determined by western blotting. NCAPG was highly expressed in EC tissues and cells and predicted poor survival for EC patients. NCAPG knockdown inhibited cell proliferation and induced apoptosis in EC cells. Additionally, NCAPG knockdown inactivated the Wnt/β-catenin pathway in EC cells. Mechanistically, β-catenin overexpression blocked the tumorigenic effects of NCAPG in EC cells. In conclusion, NCAPG silencing inhibited cell proliferation and induced apoptosis in EC cells via inhibiting the Wnt/β-catenin pathway.

NCAPG promotes the progression of lung adenocarcinoma via the TGF-β signaling pathway

Background

Lung cancer has the highest case fatality rate among cancers because of uncontrolled proliferation and early metastasis of cancer cells in the lung tissue. This study aimed to clarify the role of the non-SMC condensin I complex, subunit G (NCAPG) in lung adenocarcinoma (LUAD), explore the mechanisms of its progression, and lay the foundation for the search for new biological markers.

Methods

We analyzed overlapping differentially expressed genes (DEGs) from three datasets; a protein–protein interaction (PPI) network was subsequently constructed and analyzed using Cytoscape. We then selected NCAPG for validation because of its poor prognosis and because it has not been sufficiently studied in the context of LUAD. Immunohistochemical analysis was used to detect the expression of NCAPG in LUAD tissues, and the relationships between NCAPG and clinical parameters were analyzed. In vitro and in vivo experiments were conducted to verify the role of NCAPG in LUAD. Finally, we studied the specific mechanism of action of NCAPG in LUAD.

Results

Through comprehensive analysis of the GSE43458, GSE75037, and The Cancer Genome Atlas databases, we identified 517 overlapping DEGs. Among them, NCAPG was identified as a hub gene. Immunohistochemical analysis revealed that NCAPG was strongly associated with the clinical stage, M-classification, and N-classification. Univariate and multivariate Cox regression analyses indicated that NCAPG was a prognostic risk factor for LUAD, while the in vitro experiments showed that NCAPG overexpression promoted proliferation, migration, invasion, and epithelial-mesenchymal transition. Furthermore, knockdown of NCAPG inhibited LUAD progression, both in vitro and in vivo. Mechanistically, NCAPG overexpression increased p-Smad2 and p-Smad3 expressions in the transforming growth factor β (TGF-β) signaling pathway. Additionally, rescue experiments indicated that TGF-β signaling pathway inhibitors could restore the effect of NCAPG overexpression in LUAD cells.

Conclusions

NCAPG may promote proliferation and migration via the TGF-β signaling pathway in LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02138-w.

Mitotic chromosomes

Our understanding of the structure and function of mitotic chromosomes has come a long way since these iconic objects were first recognized more than 140 years ago, though many details remain to be elucidated. In this chapter, we start with the early history of chromosome studies and then describe the path that led to our current understanding of the formation and structure of mitotic chromosomes. We also discuss some of the remaining questions. It is now well established that each mitotic chromatid consists of a central organizing region containing a so-called "chromosome scaffold" from which loops of DNA project radially. Only a few key non-histone proteins and protein complexes are required to form the chromosome: topoisomerase IIα, cohesin, condensin I and condensin II, and the chromokinesin KIF4A. These proteins are concentrated along the axis of the chromatid. Condensins I and II are primarily responsible for shaping the chromosome and the scaffold, and they produce the loops of DNA by an ATP-dependent process known as loop extrusion. Modelling of Hi-C data suggests that condensin II adopts a spiral staircase arrangement with an extruded loop extending out from each step in a roughly helical pattern. Condensin I then forms loops nested within these larger condensin II loops, thereby giving rise to the final compaction of the mitotic chromosome in a process that requires Topo IIα.

Four Novel Prognostic Genes Related to Prostate Cancer Identified Using Co-expression Structure Network Analysis

Prostate cancer (PCa) is one of the most common malignancies for males, but very little is known about its pathogenesis. This study aimed to identify novel biomarkers associated with PCa prognosis and elucidate the underlying molecular mechanism. First, The Cancer Genome Atlas (TCGA) RNA-sequencing data were utilized to identify differentially expressed genes (DEGs) between tumor and normal samples. The DEGs were then applied to construct a co-expression and mined using structure network analysis. The magenta module that was highly related to the Gleason score (r = 0.46, p = 3e-26) and tumor stage (r = 0.38, p = 2e-17) was screened. Subsequently, all genes of the magenta module underwent function annotation. From the key module, CCNA2, CKAP2L, NCAPG, and NUSAP1 were chosen as the four candidate genes. Finally, internal (TCGA) and external data sets (GSE32571, GSE70770, and GSE141551) were combined to validate and predict the value of real hub genes. The results show that the above genes are up-regulated in PCa samples, and higher expression levels show significant association with higher Gleason scores and tumor T stage. Moreover, receiver operating characteristic curve and survival analysis validate the excellent value of hub genes in PCa progression and prognosis. In addition, the protein levels of these four genes also remain higher in tumor tissues when compared with normal tissues. Gene set enrichment analysis and gene set variation analysis for a single gene reveal the close relation with cell proliferation. Meanwhile, 11 small molecular drugs that have the potential to treat PCa were also screened. In conclusion, our research identified four potential prognostic genes and several candidate molecular drugs for treating PCa.

Genetic diversity and population structure of Tibetan sheep breeds determined by whole genome resequencing

Tibetan sheep is one of primitive Chinese sheep breeds, which achieved the divergence about 2500 years ago in Qinghai plateau region. According to different geographic conditions, especially altitudes, Tibetan sheep evolved into different breeds. In this study, we performed whole genome resequencing of 5 representative Tibetan sheep breeds. Comparative genomic analysis showed that they can be divided into different clades with a close genetic relationship. However, some genes with common selective regions were enriched for hypoxic adaptability in different breeds living at higher altitude, including GHR, BMP15, and CPLANE1. Furthermore, breed-specific selective regions about physical characteristics, especially wool growth, were found in genes such as BSND, USP24, NCAPG, and LCORL. This study could contribute to our understanding about trait formation and offer a reference for breeding of Tibetan sheep.

NCAPG Is a Promising Therapeutic Target Across Different Tumor Types

Background

With the advent of CRISPR-Cas9 genome editing tool in gene therapy, identification of aberrantly expressed genes is of great value across various cancer types. Since a large number of patients may benefit from molecular targeted gene therapy. The purpose of this study was to identify aberrantly expressed genes across various cancer types, analyze prospective mechanisms and their correlation with survival outcomes.

Results

NCAPG was highly expressed in The Cancer Genome Atlas (TCGA) database, which includes the transcriptomes of 6,647 cancer and 647 normal tissue samples from 16 cancer types. Furthermore, a predicted NCAPG overexpression rate was also observed at the protein level in 16 tumor types. Importantly, high NCAPG level was significantly associated with unfavorable survival in various cancer types such as hepatocellular carcinoma (HCC), breast, lung or ovarian cancer. The multivariate analyses demonstrated that NCAPG, TNM, and Barcelona Clinic Liver Cancer (BCLC) staging were independent risk factors for mortality of patients with HCC. Moreover, functional and pathway enrichment analysis suggested that NCAPG was closely correlated with the pathways of cell cycle, cellular senescence, and mismatch repair. By weighted gene co-expression network analysis (WGCNA), we identified NCAPG as a hub gene in the turquoise module mostly related to the survival time of HCC samples.

Conclusion

To our knowledge, this study represents a comprehensive RNA-Seq analysis of several tumor types, revealing NCAPG as a promising molecular target. NCAPG overexpression may play important roles in carcinogenesis and progression of tumors via regulating tumor-related pathways, thereby broadening the understanding of the pathogenic mechanisms and highlighting the possibility of developing novel targeted therapeutics.

Genome-wide CRISPR knockout screens identify NCAPG as an essential oncogene for hepatocellular carcinoma tumor growth

Hepatocellular carcinoma (HCC) is a common and deadly cancer with limited treatment options. Through genome-wide growth depletion screens using clustered regularly interspaced short palindromic repeats and expression profiling of primary HCC tumors, we identified 13 clinically relevant target genes with therapeutic potential. Subsequent functional annotation analysis revealed significant enrichment of these 13 genes in the cell cycle, cell death, and survival pathways. Non-structural maintenance of chromosomes condensin I complex subunit G (NCAPG) was ranked the highest among the depletion screens and multiple HCC expression datasets. Transient inhibition of NCAPG using specific small interfering RNAs resulted in a significant reduction in cell growth, migration, and the down-regulation of mitochondrial gene expression in vitro. Small homologous RNA-mediated knockdown of NCAPG significantly impaired cell viability, caused aberrant mitotic division, fragmented the mitochondrial network, and increased cell death in vitro. HCC cells with a reduced expression of NCAPG formed significantly smaller xenograft tumors in vivo. Importantly, high NCAPG expression was significantly associated with poorer overall and disease-free survival in HCC patients. High NCAPG expression is a novel prognostic biomarker to predict HCC early recurrence after surgical resection. In conclusion, NCAPG is an essential gene for HCC tumor cell survival. It represents a promising novel target for treating HCC and a prognostic biomarker for clinical management of HCC.-Wang, Y., Gao, B., Tan, P. Y., Handoko, Y. A., Sekar, K., Deivasigamani, A., Seshachalam, V. P., OuYang, H.-Y., Shi, M., Xie, C., Goh, B. K. P., Ooi, L. L., Hui, K. M. Genome-wide CRISPR knockout screens identify NCAPG as an essential oncogene for hepatocellular carcinoma tumor growth.

MicroRNA‑181c suppresses growth and metastasis of hepatocellular carcinoma by modulating NCAPG

Purpose: Numerous studies have shown that the expression of microRNA-181c (miR-181c) is inhibited in various cancers, which suggests that it has a cancer suppressive effect. In the current study, we evaluated the regulation and characteristics of miR-181c in human hepatocellular carcinoma (HCC).

Materials and methods: Samples of tumor tissues and adjacent non-tumor tissues were collected from 52 patients with HCC, and expression levels of miR-181c in these samples were investigated via quantitative real-time polymerase chain reaction. HCC cell migration and invasion were investigated via wound healing assays and transwell assays. HCC cell apoptosis rates were assessed via flow cytometry, and HCC proliferation was assessed via 5-ethynyl-20-deoxyuridine assays. In vivo tumors were initiated by subcutaneously inoculating HCC cells into nude mice. And various biomarkers were investigated via western blotting.

Results: In microarray datasets and tumor tissues, significant downregulation of miR-181c was apparent compared with non-tumorous adjacent tissues. Expression of miR-181c in HCC cells was also significantly lower than it was in normal human liver cells. miR-181c regulated the migration, invasion, apoptosis, and proliferation of HCC cell lines in vitro, and tumor development in vivo. Observations also suggest that miR-181c regulates NCAPG in HCC cells, and its expression affects cellular invasion, migration, proliferation, and apoptosis. There was a negative correlation between miR-181c expression and NCAPG in HCC tissue samples.

Conclusion: miR-181c exhibits tumor-suppression via the regulation of NCAPG levels.

Cdk1-dependent phosphorylation of KIF4A at S1186 triggers lateral chromosome compaction during early mitosis

Chromosome organization during cell division is achieved through the timely association of proteins with chromatin and is regulated by protein phosphorylation. Kinesin family member 4A (KIF4A) plays an important role in the chromosome organization through the formation of the chromosome scaffold structure. However, the relationship between the function of KIF4A and its phosphorylation remains unclear. Here, we demonstrate that Cdk1-dependent phosphorylation of KIF4A at S1186 is required for chromosome binding and chromosome scaffold formation. The KIF4A mutant, which is not phosphorylated at S1186, was found to localize to the nucleus during interphase but did not accumulate in the chromosome scaffold after nuclear envelope breakdown. In addition, defects in KIF4A phosphorylation were found to disrupt the interaction of KIF4A with the condensin I complex. As a result, the morphology of the chromosomes was observed to be laterally decondensed, without condensin I in the chromosome scaffold. Additionally, a defect in chromosome segregation, chromosome bridge formation, was often observed. Although both KIF4A and condensin I disappeared from the chromosomes, the chromosomal localization of condensin II was not affected. Collectively, our novel results revealed that Cdk1-dependent KIF4A phosphorylation at S1186 is a trigger for chromosomal organization during early mitosis.

Silencing non-SMC chromosome-associated polypeptide G inhibits proliferation and induces apoptosis in hepatocellular carcinoma cells

The present study was designed to investigate the significance of non-structural maintenance of chromosomes (non-SMC) chromosome-associated polypeptide G (NCAPG), a subunit of condensin complex I, in the development of hepatocellular carcinoma (HCC). NCAPG protein expression in human HCC and paracancerous hepatic tissues were examined using immunohistochemistry, and NCAPG mRNA expression in HCC cell lines were quantified using quantitative RT-PCR. Lentivirus-mediated RNA interference was used to silence NCAPG in HCC cells. Cell proliferation was monitored by MTT assay. Cell colony-forming capacity was measured by colony formation assay. Apoptosis was determined by flow cytometry. The results showed that increased protein expression of NCAPG was found in HCC tissues compared with the matched paracancerous hepatic tissues. At the mRNA level, increased expression of NCAPG was found in HCC cells as opposed to the normal hepatocytes. Silencing of NCAPG in BEL-7404 and SMMC-7721 cells led to decreased cell proliferation and increased apoptosis. These changes were associated with increased mRNA expressions of P53, P27, and Bad, but decreased mRNA expression of EGFR, Akt, survivin, and JNK. NCAPG might play an oncogenic role in the development of liver cancer. Further studies to clarify its role and underlying mechanisms in the development of liver cancer are warranted.

Non-SMC Condensin I Complex, Subunit G (NCAPG) is a Novel Mitotic Gene Required for Hepatocellular Cancer Cell Proliferation and Migration

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide. Currently, only chemoembolization and sorafenib have shown survival benefits for advanced HCC. There are major unmet needs in HCC management and the discovery of new therapeutic targets. Here we identified NCAPG (non-SMC condensin I complex, subunit G) as a novel mitotic gene required for HCC cell proliferation and migration through siRNA knockdown of a panel of novel overexpressed genes in HCC based on The Cancer Genome Atlas (TCGA) dataset. We found that knockdown of NCAPG induces HCC cell mitosis and inhibits cell growth, proliferation, and migration in vitro. Tetracycline-inducible shRNA knockdown of NCAPG inhibits tumor growth of HCC cells in vivo. Moreover, overexpression of NCAPG in clinical HCC samples was associated with recurrence and survival of patients. The overexpression of NCAPG was significantly correlated with the overexpression of CCNB1 (G2/mitotic-specific cyclin B1), a regulatory protein involved in mitosis. Therefore, NCAPG may provide a promising novel therapeutic target for the treatment of advanced HCC in the future.

Interdependency and phosphorylation of KIF4 and condensin I are essential for organization of chromosome scaffold

Kinesin family member 4 (KIF4) and condensins I and II are essential chromosomal proteins for chromosome organization by locating primarily to the chromosome scaffold. However, the mechanism of how KIF4 and condensins localize to the chromosome scaffold is poorly understood. Here, we demonstrate a close relationship between the chromosome localization of KIF4 and condensin I, but not condensin II, and show that KIF4 and condensin I assist each other for stable scaffold formation by forming a stable complex. Moreover, phosphorylation of KIF4 and condensin I by Aurora B and polo-like kinase 1 (Plk1) is important for KIF4 and condensin I localization to the chromosome. Aurora B activity facilitates the targeting of KIF4 and condensin I to the chromosome, whereas Plk1 activity promotes the dissociation of these proteins from the chromosome. Thus, the interdependency between KIF4 and condensin I, and their phosphorylation states play important roles in chromosome scaffold organization during mitosis.

Polymorphic regions affecting human height also control stature in cattle

Orthologous positions of 55 genes associated with height in four human populations were located on the bovine genome. Single nucleotide polymorphisms close to eight of these genes were significantly associated with stature in cattle (Bos taurus and Bos indicus). This suggests that these genes may contribute to controlling stature across mammalian species.

Detection of condensin I and II in maturing pig oocytes

The multiprotein complexes known as condensins (I and II) are major players in chromosome dynamics in mitotic and meiotic cells. Here, we report for the first time the detection of different condensin subunits from both complexes in mammalian oocytes. Using immunoblotting analysis we examined expression levels of condensin subunits during meiotic maturation of porcine oocytes. The expression of the core subunit structural maintenance of chromosomes 2 (SMC2), identical in both condensin complexes, did not change significantly during maturation. Similarly, there was no significant change in the expression of the chromosome associated protein (CAP)-H and CAP-H2 subunits, components of condensin I and II, respectively. Conversely, the expression profiles of CAP-G, CAP-D2 (condensin I) and CAP-D3 (condensin II) were more interesting. At least two isoforms of the CAP-D2 subunit were detected, along with three isoforms of the CAP-D3 and CAP-G subunits. We suggest that this diverse migration of subunit isoforms is due to post-translational modification. Earlier, it was reported that non-SMC proteins are phosphorylated by cyclin-dependent kinase 1. In the present study, we analysed the phosphorylation status of the three subunits in oocyte extracts using alkaline phosphatase treatment and we found that at least the fastest migrating form of CAP-D3 was likely to be phosphorylated in maturing porcine oocytes. In addition, the localisation of CAP-H and CAP-H2 subunits was examined using immunofluorescence staining with specific antibodies, as well as following microinjection of their enhanced green fluorescent protein-tagged mRNA into germinal vesicle-stage oocytes. CAP-H was found in the cytoplasm, whereas CAP-H2 was localised within the nucleus.

Safeguarding entry into mitosis: the antephase checkpoint

Maintenance of genomic stability is needed for cells to survive many rounds of division throughout their lifetime. Key to the proper inheritance of intact genome is the tight temporal and spatial coordination of cell cycle events. Moreover, checkpoints are present that function to monitor the proper execution of cell cycle processes. For instance, the DNA damage and spindle assembly checkpoints ensure genomic integrity by delaying cell cycle progression in the presence of DNA or spindle damage, respectively. A checkpoint that has recently been gaining attention is the antephase checkpoint that acts to prevent cells from entering mitosis in response to a range of stress agents. We review here what is known about the pathway that monitors the status of the cells at the brink of entry into mitosis when cells are exposed to insults that threaten the proper inheritance of chromosomes. We highlight issues which are unresolved in terms of our understanding of the antephase checkpoint and provide some perspectives on what lies ahead in the understanding of how the checkpoint functions.