The clinicopathological significance of BUBR1 overexpression in hepatocellular carcinoma

The Prognostic Importance of Ki-67 in Gastrointestinal Carcinomas: A Meta-analysis and Multi-omics Approach

PURPOSE

This study aimed to determine if Ki-67, a commonly used marker to measure tumor proliferation, is a reliable prognostic factor in various types of gastrointestinal (GI) cancers based on current high-quality multivariable evidence.

METHODS

A comprehensive search was conducted in PubMed, Embase, Scopus, and ISI Web of Science databases to investigate the association between Ki-67 positivity and overall survival (OS) and disease/recurrence-free survival (DFS/RFS) in GI cancers. Heterogeneity was assessed using Chi-square-based Q and I2 analyses and publication bias using funnel plots and Egger's analysis. In addition, Ki-67 levels in different GI cancers were examined by different platforms. The prognostic capability of Ki-67, gene ontology (GO), and pathway enrichment analysis were obtained from GEPIA2 and STRING.

RESULTS

Totally, 61 studies, involving 13,034 patients, were deemed eligible for our evaluation. The combined hazard ratios (HRs) demonstrated the prediction ability of overexpressed Ki-67 for a worse OS (HR: 1.67, P < 0.001; HR: 1.37, P = 0.021) and DFS/RFS (HR: 2.06, P < 0.001) in hepatocellular and pancreatic malignancies, respectively, as confirmed by multi-omics databases. However, similar correlation was not found in esophageal, gastric, and colorectal cancers. Furthermore, most of the associations were identified to be robust based on different subcategories and publication bias assessment. Finally, enriched Ki-67-related genes were found to be involved in various important signaling pathways, such as cell cycle, P53 signaling network, and DNA damage responses.

CONCLUSION

This study supports that Ki-67 can serve as an independent prognostic biomarker for pancreatic and hepatocellular malignancies in clinical settings.

BubR1 controls starvation-induced lipolysis via IMD signaling pathway in Drosophila

Lipolysis, the key process releasing fat acids to generate energy in adipose tissues, correlates with starvation resistance. Nevertheless, its detail mechanisms remain elusive. BubR1, an essential mitotic regulator, ensures proper chromosome alignment and segregation during mitosis, but its physiological functions are largely unknown. Here, we use Drosophila adult fat body, the major lipid storage organ, to study the functions of BubR1 in lipolysis. We show that both whole body- and fat body-specific BubR1 depletions increase lipid degradation and shorten the lifespan under fasting but not feeding. Relish, the conserved regulator of IMD signaling pathway, acts as the downstream target of BubR1 to control the expression level of Bmm and modulate the lipolysis upon fasting. Thus, our study reveals new functions of BubR1 in starvation-induced lipolysis and provides new insights into the molecular mechanisms of lipolysis mediated by IMD signaling pathway.

BUBR1 as a Prognostic Biomarker in Canine Oral Squamous Cell Carcinoma

Chromosomal instability (CIN) plays a key role in the carcinogenesis of several human cancers and can be related to the deregulation of core components of the spindle assembly checkpoint (SAC) including BUBR1 protein kinase. These proteins have been related to tumor development and poor survival rates in human patients with oral squamous cell carcinoma (OSCC). To investigate the expression of the SAC proteins BUBR1, BUB3 and SPINDLY and also Ki-67 in canine OSCC, we performed an immunohistochemical evaluation in 60 canine OSCCs and compared them with clinical and pathological variables. BUBR1, Ki-67, BUB3 and SPINDLY protein expressions were detected in all cases and classified as with a high-expression extent score in 31 (51.7%) cases for BUBR1, 33 (58.9%) cases for BUB3 and 28 (50.9%) cases for SPINDLY. Ki-67 high expression was observed in 14 (25%) cases. An independent prognostic value for BUBR1 was found, where high BUBR1 expression was associated with lower survival (p = 0.012). These results indicate that BUBR1 expression is an independent prognostic factor in these tumors, suggesting the potential use for clinical applications as a prognostic biomarker and also as a pharmacological target in canine OSCC.

Identification of Differentially Expressed Genes Associated with the Prognosis and Diagnosis of Hepatocellular Carcinoma by Integrated Bioinformatics Analysis

OBJECTIVE

The goal of this study was to understand the possible core genes associated with hepatocellular carcinoma (HCC) pathogenesis and prognosis.

METHODS

GEO contains datasets of gene expression, miRNA, and methylation patterns of diseased and healthy/control patients. The GSE62232 dataset was selected by employing the server Gene Expression Omnibus. A total of 91 samples were collected, including 81 HCC and 10 healthy samples as control. GSE62232 was analysed through GEO2R, and Functional Enrichment Analysis was performed to extract rational information from a set of DEGs. The Protein-Protein Relationship Networking search method has been used for extracting the interacting genes. MCC method was used to calculate the top 10 genes according to their importance. Hub genes in the network were analysed using GEPIA to estimate the effect of their differential expression on cancer progression.

RESULTS

We identified the top 10 hub genes through CytoHubba plugin. These included BUB1, BUB1B, CCNB1, CCNA2, CCNB2, CDC20, CDK1 and MAD2L1, NCAPG, and NDC80. NCAPG and NDC80 reported for the first time in this study while the remaining from a recently reported literature. The pathogenesis of HCC may be directly linked with the aforementioned genes. In this analysis, we found critical genes for HCC that showed recommendations for future prognostic and predictive biomarkers studies that could promote selective molecular therapy for HCC.

Meta-Analysis of Esophageal Cancer Transcriptomes Using Independent Component Analysis

Independent Component Analysis is a matrix factorization method for data dimension reduction. ICA has been widely applied for the analysis of transcriptomic data for blind separation of biological, environmental, and technical factors affecting gene expression. The study aimed to analyze the publicly available esophageal cancer data using the ICA for identification and comprehensive analysis of reproducible signaling pathways and molecular signatures involved in this cancer type. In this study, four independent esophageal cancer transcriptomic datasets from GEO databases were used. A bioinformatics tool « BiODICA-Independent Component Analysis of Big Omics Data» was applied to compute independent components (ICs). Gene Set Enrichment Analysis (GSEA) and ToppGene uncovered the most significantly enriched pathways. Construction and visualization of gene networks and graphs were performed using the Cytoscape, and HPRD database. The correlation graph between decompositions into 30 ICs was built with absolute correlation values exceeding 0.3. Clusters of components-pseudocliques were observed in the structure of the correlation graph. The top 1,000 most contributing genes of each ICs in the pseudocliques were mapped to the PPI network to construct associated signaling pathways. Some cliques were composed of densely interconnected nodes and included components common to most cancer types (such as cell cycle and extracellular matrix signals), while others were specific to EC. The results of this investigation may reveal potential biomarkers of esophageal carcinogenesis, functional subsystems dysregulated in the tumor cells, and be helpful in predicting the early development of a tumor.

Studying the Role of Chromosomal Instability (CIN) in GI Cancers Using Patient-derived Organoids

Chromosomal instability (CIN) is associated with the initiation and progression of gastrointestinal (GI) tract cancers. Cancers of the GI tract are typically characterized by altered chromosome numbers. While the dynamics of CIN have been extensively characterized in 2D monolayer cell cultures derived from GI tumors, the tumor microenvironment and 3D tumor architecture also contribute to the progression of CIN, which is not captured in 2D cell culture systems. To overcome these limitations, self-organizing cellular structures that retain organ-specific 3D architecture, namely organoids, have been derived from various tissues of the GI tract. Organoids derived from normal tissue and patient tumors serve as a useful paradigm to study the crosstalk between tumor cells in the context of a tissue microenvironment and its impact on chromosomal stability. Such a paradigm, therefore, has a considerable advantage over 2D cell culture systems in drug screening and personalized medicine. Here, we review the importance of patient-derived tumor organoids (PDTOs) as a model to study CIN in cancers of the GI tract.

Identification of grade-related genes and construction of a robust genomic-clinicopathologic nomogram for predicting recurrence of bladder cancer

BACKGROUND

Bladder cancer (BC) is a common tumor in the urinary system with a high recurrence rate. The individualized treatment and follow-up after surgery is the key to a successful outcome. Currently, the surveillance strategies are mainly depending on tumor stage and grade. Previous evidence has proved that tumor grade was a significant and independent risk factor of BC recurrence. Exploring the grade-related genes may provide us a new approach to predict prognosis and guide the post-operative treatment in BC patients.

METHODS

In this study, the weighted gene co-expression network analysis was applied to identify the hub gene module correlated with BC grade using GSE71576. After constructing a protein-protein interaction (PPI) network with the hub genes inside the hub gene module, we identified some potential core genes. TCGA and another independent dataset were used for further validation.

RESULTS

The results revealed that the expression of AURKA, CCNA2, CCNB1, KIF11, TTK, BUB1B, BUB1, and CDK1 were significantly higher in high-grade BC, showing a strong ability to distinguish BC grade. The expression levels of the 8 genes in normal, paracancerous, tumorous, and recurrent bladder tissues were progressively increased. By conducting survival analysis, we proved their prognostic value in predicting the recurrence of BC. Eventually, we constructed a prognostic nomogram by combining the 8-core-gene panel with clinicopathologic features, which had shown great performance in predicting the recurrence of BC.

CONCLUSION

We identified 8 core genes that revealed a significant correlation with the tumor grade as well as the recurrence of BC. Finally, we proved the value of a novel prognostic nomogram for predicting the relapse-free survival of BC patients after surgery, which could guide their treatment and follow-up.

Identification of key genes and biological pathways in lung adenocarcinoma via bioinformatics analysis

Lung adenocarcinoma (LUAD) accounts for the majority of cancer-related deaths worldwide. Our study identified key LUAD genes and their potential mechanism via bioinformatics analysis of public datasets. GSE10799, GSE40791, and GSE27262 microarray datasets were retrieved from the Gene Expression Omnibus (GEO) database. The RobustRankAggreg package was used to perform a meta-analysis, and 50 upregulated genes and 87 downregulated genes overlapped in three datasets. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID). Furthermore, protein-protein interaction (PPI) networks of the differentially expressed genes (DEGs) were built by the Search Tool for the Retrieval of Interacting Genes (STRING) and 22 core genes were identified by Molecular Complex Detection (MCODE) and visualized with Cytoscape. Subsequently, these core genes were analyzed by the Kaplan-Meier Plotter and Gene Expression Profiling Interactive Analysis (GEPIA). The results showed that all 22 genes were significantly associated with reduced survival rates. For GEPIA, the expression of only one gene was not significantly different between LUAD tissues and normal tissues. A KEGG pathway enrichment reanalysis of the 21 genes identified five key genes (CCNB1, BUB1B, CDC20, TTK, and MAD2L1) in the cell cycle pathway. Finally, the Comparative Toxicogenomics Database (CTD) website was used to explore the relationship between these key genes and certain drugs. Based on the bioinformatics analysis, five key genes were identified in LUAD, and drugs closely associated these genes can provide clues for the treatment and prognosis of LUAD.

Identification of a five-gene signature for predicting the progression and prognosis of stage I endometrial carcinoma

Uterine corpus endometrial carcinoma (UCEC) is often diagnosed at an early clinical stage based on abnormal vaginal bleeding. However, the prognosis of UCEC is poor. The present study was conducted to identify novel tumor grade-related genes with the potential to predict the prognosis and progression of UCEC. A total of three gene expression microarray datasets were downloaded from the Gene Expression Omnibus database, and one RNA-sequencing dataset with corresponding clinical information of patients with UCEC was obtained from The Cancer Genome Atlas database. In summary, 1,447 differentially expressed genes (DEGs) were identified between endometrial cancerous tissues and normal endometrial tissues. Weighted gene co-expression network analysis was performed to assess the associations between DEGs and clinical traits. In total, five genes were found to be highly associated with the tumorigenesis and prognosis of UCEC. Among them, BUB1 mitotic checkpoint serine/threonine kinase B, cyclin B1, cell-division cycle protein 20 and non-SMC condensing I complex subunit G were involved in cell cycle regulation pathways, and DLG-associated protein 5 was involved in the Notch receptor 3 signaling pathway based on functional enrichment analyses. Of the five genes, four were highly expressed in endometrial cancerous tissues compared with normal endometrial tissues at the protein level. In addition, the higher expression of these genes predicted a higher tumor grade and worse overall survival. In conclusion, the present study revealed a 5-gene signature that can be used to predict the progression of UCEC.

Identification of hub genes involved in the occurrence and development of hepatocellular carcinoma via bioinformatics analysis

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy, which is a major cause of cancer morbidity and mortality worldwide. Thus, the aim of the present study was to identify the hub genes and underlying pathways of HCC via bioinformatics analyses. The present study screened three datasets, including GSE112790, GSE84402 and GSE74656 from the Gene Expression Omnibus (GEO) database, and downloaded the RNA-sequencing of HCC from The Cancer Genome Atlas (TCGA) database. The differentially expressed genes (DEGs) in both the GEO and TCGA datasets were filtered, and the screened DEGs were subsequently analyzed for functional enrichment pathways. A protein-protein interaction (PPI) network was constructed, and hub genes were further screened to create the Kaplan-Meier curve using cBioPortal. The expression levels of hub genes were then validated in different datasets using the Oncomine database. In addition, associations between expression and tumor grade, hepatitis virus infection status, satellites and vascular invasion were assessed. A total of 126 DEGs were identified, containing 70 upregulated genes and 56 downregulated genes from the GEO and TCGA databases. By constructing the PPI network, the present study identified hub genes, including cyclin B1 (CCNB1), cell-division cycle protein 20 (CDC20), cyclin-dependent kinase 1, BUB1 mitotic checkpoint serine/threonine kinase β (BUB1B), cyclin A2, nucleolar and spindle associated protein 1, ubiquitin-conjugating enzyme E2 C (UBE2C) and ZW10 interactor. Furthermore, upregulated CCNB1, CDC20, BUB1B and UBE2C expression levels indicated worse disease-free and overall survival. Moreover, a meta-analysis of tumor and healthy tissues in the Oncomine database demonstrated that BUB1B and UBE2C were highly expressed in HCC. The present study also analyzed the data of HCC in TCGA database using univariate and multivariate Cox analyses, and demonstrated that BUB1B and UBE2C may be used as independent prognostic factors. In conclusion, the present study identified several genes and the signaling pathways that were associated with tumorigenesis using bioinformatics analyses, which could be potential targets for the diagnosis and treatment of HCC.

Identification of new candidate genes and signalling pathways associated with the development of neuroendocrine pancreatic tumours based on next generation sequencing data

Despite advances in classification, treatment, and imaging, neuroendocrine tumours remain a clinically complex subject. In this work, we studied the genetic profile of well-differentiated pancreatic neuroendocrine tumours (PanNETs) in a cohort of Caucasian patients and analysed the signalling pathways and candidate genes potentially associated with the development of this oncological disease. Twenty-four formalin-fixed paraffin-embedded (FFPE) samples of well-differentiated PanNETs were subjected to massive parallel sequencing using the targeted gene panel (409 genes) of the Illumina NextSeq 550 platform (San Diego, USA). In 24 patients, 119 variants were identified in 54 genes. The median mutation rate per patient was 5 (2.8-7). The detected genetic changes were dominated by missense mutations (67%) and nonsense mutations (29%). 18% of the mutations were activating, 35% of the variants led to a loss of function of the encoded protein, and 52% were not classified. Twenty-six variants were described as new. Functionally significant changes in the tertiary structure and activity of the protein molecules in an in silico assay were predicted for 5 new genetic variants. The 5 highest priority candidate genes were selected: CREB1, TCF12, PRKAR1A, BCL11A, and BUB1B. Genes carrying the identified mutations participate in signalling pathways known to be involved in PanNETs; in addition, 38% of the cases showed genetic changes in the regulation of the SMAD2/3 signalling pathway. Well-differentiated PanNETs in a Russian cohort demonstrate various molecular genetic features, including new genetic variations and potential driver genes. The highlighted molecular genetic changes in the SMAD2/3 signalling pathway suggest new prospects for targeted therapy.

Identification of potential key genes and pathways in hepatitis B virus-associated hepatocellular carcinoma by bioinformatics analyses

Chronic hepatitis B virus (HBV) is one of the leading causes of hepatocellular carcinoma (HCC). The precise molecular mechanisms by which HBV contributes to HCC development are not fully understood. The key genes and pathways involved in the transformation of nontumor hepatic tissues into HCC tissues in patients with HBV infection are essential to guide the treatment of HBV-associated HCC. Five datasets were collected from the Gene Expression Omnibus database to form a large cohort. Differentially expressed genes (DEGs) were identified between HCC tissues and nontumor hepatic tissues from HBV-infected patients using the ‘limma’ package. The top 50 upregulated and top 50 downregulated DEGs in HCC vs. nontumor tissues were demonstrated in subsets by heat maps. Based on the DEGs, Gene Ontology functional and Kyoto Encyclopedia of Genes and Genomes pathways enrichment analyses were performed. Several key pathways of the up- and downregulated DEGs were identified and presented by protein-protein interaction (PPI) networks. A total of 1,934 DEGs were identified. The upregulated DEGs were primarily associated with the ‘cell cycle’. Among the DEGs enriched in the ‘cell cycle’ pathway, 6 genes had a log₂-fold change >2: SFN, BUB1B, TTK, CCNB1, CDK1 and CDC20. The downregulated DEGs were primarily associated with the metabolic pathways, such as ‘carbon metabolism’, ‘glycine, serine and threonine metabolism’, ‘tryptophan metabolism’, ‘retinol metabolism’ and ‘alanine, aspartate and glutamate metabolism’. The DEGs in the ‘cell cycle’ and ‘metabolic pathways’ were presented by the PPI networks respectively. Overall, the present study provides new insights into the specific etiology of HCC and molecular mechanisms for the transformation of nontumor hepatic tissues into HCC tissues in patients with a history of HBV infection and several potential therapeutic targets for targeted therapy in these patients.

Defective mitosis-linked DNA damage response and chromosomal instability in liver cancer

Hepatocellular carcinoma (HCC), the most common form of liver cancer, represents a health problem in hepatic viruses-eradicating era because obesity, type 2 diabetes, and nonalcoholic steatohepatitis (NASH) are considered emerging pathogenic factors. Metabolic disorders underpin mitotic errors that lead to numerical and structural chromosome aberrations in a significant proportion of cell divisions. Here, we review that genomically unstable HCCs show evidence for a paradoxically DNA damage response (DDR) which leads to ongoing chromosome segregation errors. The understanding of DDR induced by defective mitoses is crucial to our ability to develop or improve liver cancer therapeutic strategies.

Overexpression of BUB1B, CCNA2, CDC20, and CDK1 in tumor tissues predicts poor survival in pancreatic ductal adenocarcinoma

Overexpressed genes in tumors usually contributed to aggressiveness in pancreatic ductal adenocarcinoma (PDAC). Using Gene Expression Omnibus (GEO) profiles including GSE46234, GSE71989, and GSE107610, we detected overexpressed genes in tumors with R program, which were enriched by Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene ontology (GO), and Reactome pathway databases. Then, we performed a survival analysis of enriched genes based on TCGA profile. Our results revealed that high BUB1B, CCNA2, CDC20, and CDK1 expression in tumors was significantly associated with worse overall survival (OS) (Log rank P=0.00338, P=0.0447, P=0.00965, and P=0.00479, respectively), which was validated using a Kaplan–Meier plotter with a median cutoff (Log rank P=0.028, P=0.0035, P=0.039, and P=0.0033, respectively). Moreover, overexpression of BUB1B, CCNA2, CDC20, and CDK1 in tumor tissues was significantly associated with disease-free survival (DFS) in PDAC patients (Log rank P=0.00565, P=0.0357, P=0.00104, and P=0.00121, respectively). BUB1B, CCNA2, CDC20, and CDK1 were significantly overexpressed in deceased PDAC patients (all P<0.01) and in patients with recurrence/disease progression (all P<0.05). In addition, PDAC patients with neoplasms of histologic grade G3-4 had significantly higher BUB1B, CCNA2 and CDC20 levels (all P<0.05). In conclusion, the up-regulation of BUB1B, CCNA2, CDC20, CDK1, and WEE1 in tumor tissues are associated with worse OS and DFS in PDAC and is correlated with advanced tumor stage and tumor development.

Co-expression Network Analysis Identifies Four Hub Genes Associated With Prognosis in Soft Tissue Sarcoma

Background: Soft tissue sarcomas (STS) are heterogeneous tumors derived from mesenchymal cells that differentiate into soft tissues. The prognosis of patients who present with an STS is influenced by the regulation of a complex gene network. Methods: Weighted gene co-expression network analysis (WGCNA) was performed to identify gene modules associated with STS (Samples = 156). Results: Among the 11 modules identified, the black and blue modules were highly correlated with STS. However, using preservation analysis, the black module demonstrated low preservation, therefore the blue module was chosen as the module of interest. Furthermore, a total of 20 network hub genes were identified in the blue module, 12 of which were also hub nodes in the protein-protein interaction network of the module genes. Following additional verification, 4 of 12 genes (RRM2, BUB1B, CENPF, and KIF20A) demonstrated poorer overall survival and disease-free survival rate in the test datasets. In addition, gene set enrichment analysis (GSEA) demonstrated that samples with a high level of blue module eigengene (ME) were enriched in cell cycle and metabolism associated signaling pathways. Conclusion: In summary, co-expression network analysis identified four hub genes associated with prognosis for STS, which may diminish the prognosis by influencing cell cycle and metabolism associated signaling pathways.

The Anaphase Promoting Complex/Cyclosome (APC/C): A Versatile E3 Ubiquitin Ligase

In the present chapter we discuss the essential roles of the human E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) in mitosis as well as the emerging evidence of important APC/C roles in cellular processes beyond cell division control such as regulation of genomic integrity and cell differentiation of the nervous system. We consider the potential incipient role of APC/C dysregulation in the pathophysiology of the neurological disorder Alzheimer's disease (AD). We also discuss how certain Deoxyribonucleic Acid (DNA) and Ribonucleic Acid (RNA) viruses take control of the host's cell division regulatory system through harnessing APC/C ubiquitin ligase activity and hypothesise the plausible molecular mechanisms underpinning virus manipulation of the APC/C. We also examine how defects in the function of this multisubunit protein assembly drive abnormal cell proliferation and lastly argue the potential of APC/C as a promising therapeutic target for the development of innovative therapies for the treatment of chronic malignancies such as cancer.

Determining consistent prognostic biomarkers of overall survival and vascular invasion in hepatocellular carcinoma

Background: Potential prognostic biomarker candidates for hepatocellular carcinoma (HCC) are abundant, but their generalizability is unexplored. We cross-validated markers of overall survival (OS) and vascular invasion in independent datasets. Methods: The literature search yielded 318 genes related to survival and 52 related to vascular invasion. Validation was performed in three datasets (RNA-seq, n = 371; Affymetrix arrays, n = 91; Illumina gene chips, n = 135) by uni- and multivariate Cox regression and Mann-Whitney U-test, separately for Asian and Caucasian patients. Results: One hundred and eighty biomarkers remained significant in Asian and 128 in Caucasian subjects at p < 0.05. After multiple testing correction BIRC5 (p = 1.9 × 10^-10), CDC20 (p = 2.5 × 10^-9) and PLK1 (p = 3 × 10^-9) endured as best performing genes in Asian patients; however, none remained significant in the Caucasian cohort. In a multivariate analysis, significance was reached by stage (p = 0.0018) and expression of CENPH (p = 0.0038) and CDK4 (p = 0.038). KIF18A was the only gene predicting vascular invasion in the Affymetrix and Illumina cohorts (p = 0.003 and p = 0.025, respectively). Conclusion: Overall, about half of biomarker candidates failed to retain prognostic value and none were better than stage predicting OS. Impact: Our results help to eliminate biomarkers with limited capability to predict OS and/or vascular invasion.

Aneuploidy: Cancer strength or vulnerability?

Aneuploidy is a very rare and tissue‐specific event in normal conditions, occurring in a low number of brain and liver cells. Its frequency increases in age‐related disorders and is one of the hallmarks of cancer. Aneuploidy has been associated with defects in the spindle assembly checkpoint (SAC). However, the relationship between chromosome number alterations, SAC genes and tumor susceptibility remains unclear. Here, we provide a comprehensive review of SAC gene alterations at genomic and transcriptional level across human cancers and discuss the oncogenic and tumor suppressor functions of aneuploidy. SAC genes are rarely mutated but frequently overexpressed, with a negative prognostic impact on different tumor types. Both increased and decreased SAC gene expression show oncogenic potential in mice. SAC gene upregulation may drive aneuploidization and tumorigenesis through mitotic delay, coupled with additional oncogenic functions outside mitosis. The genomic background and environmental conditions influence the fate of aneuploid cells. Aneuploidy reduces cellular fitness. It induces growth and contact inhibition, mitotic and proteotoxic stress, cell senescence and production of reactive oxygen species. However, aneuploidy confers an evolutionary flexibility by favoring genome and chromosome instability (CIN), cellular adaptation, stem cell‐like properties and immune escape. These properties represent the driving force of aneuploid cancers, especially under conditions of stress and pharmacological pressure, and are currently under investigation as potential therapeutic targets. Indeed, promising results have been obtained from synthetic lethal combinations exploiting CIN, mitotic defects, and aneuploidy‐tolerating mechanisms as cancer vulnerability.

Upregulation of BUB1B, CCNB1, CDC7, CDC20, and MCM3 in Tumor Tissues Predicted Worse Overall Survival and Disease-Free Survival in Hepatocellular Carcinoma Patients

OBJECTIVE

To evaluate the association between upregulated differentially expressed genes (DEGs) and the outcomes of patients with hepatocellular carcinoma (HCC).

METHODS

Using Gene Expression Omnibus (GEO) datasets including GSE45436, GSE55092, GSE60502, GSE84402, and GSE17548, we detected upregulated DEGs in tumors. KEGG, GO, and Reactome enrichment analysis of the DEGs was conducted to clarify their function. The impact of the upregulated DEGs on patients' survival was analyzed based on TCGA profile.

RESULTS

161 shared upregulated DEGs were identified among GSE45436, GSE55092, GSE60502, and GSE84402 profiles. Cell cycle was the shared pathway/biological process in the gene sets investigation among databases of KEGG, GO, and Reactome. After being validated in GSE17548, 13 genes including BUB1B, CCNA2, CCNB1, CCNE2, CDC20, CDC6, CDC7, CDK1, CDK4, CDKN2A, CHEK1, MAD2L1, and MCM3 in cell cycle pathway were shared in the three databases for enrichment. The expression of BUB1B, CCNB1, CDC7, CDC20, and MCM3 was upregulated in HCC tissues when compared with adjacent normal tissues in 6.67%, 7.5%, 8.06%, 5.56%, and 9.72% of HCC patients, respectively. Overexpression of BUB1B, CCNB1, CDC7, CDC20, and MCM3 in HCC tissues accounted for poorer overall survival (OS) and disease-free survival (DFS) in HCC patients (all log rank P < 0.05). BUB1B, CCNB1, CDC7, CDC20, and MCM3 were all overexpressed in HCC patients with neoplasm histologic grade G3-4 compared to those with G1-2 (all P < 0.05). BUB1B, CCNB1, and CDC20 were significantly upregulated in HCC patients with vascular invasion (all P < 0.05). Additionally, levels of BUB1B, CCNB1, CDC7, and CDC20 were significantly higher in HCC patients deceased, recurred, or progressed (all P < 0.05).

CONCLUSION

Correlated with advanced histologic grade and/or vascular invasion, upregulation of BUB1B, CCNB1, CDC7, CDC20, and MCM3 in HCC tissues predicted worse OS and DFS in HCC patients. These genes could be novel therapeutic targets for HCC treatment.

BUBR1 overexpression predicts disease-specific survival after nephroureterectomy in patients with upper tract urothelial carcinoma

OBJECTIVE

To date, there are few reliable markers to distinguish tumors with aggressive characteristics in upper tract urothelial carcinoma. The purpose of this study was to identify a biomarker related to genetic instability (chromosomal instability or microsatellite instability) with prognostic value, in patients with upper tract urothelial carcinoma.

METHODS

Expression of chromosomal instability-related markers (BUBR1, p53, polo-like kinase 1) and microsatellite instability-related markers (mismatch repair proteins, MLH1 and MSH2) were assessed by immunohistochemistry in 100 patients who had radical nephroureterectomy for upper tract urothelial carcinoma. Numerical aberrations of chromosomes 7, 9 and 17 were evaluated by fluorescence in situ hybridization, which allowed an estimation of the degree of chromosomal instability. BUB1B copy number was examined by array-based comparative genomic hybridization in 32 patients with upper tract urothelial carcinoma.

RESULTS

BUBR1 status was most significantly correlated with chromosomal instability-related and low mismatch repair parameters, according to the molecular biomarkers examined. Overexpression of BUBR1 is frequently detected in tumors with higher histological grade (P < 0.0001) and is significantly associated with chromosomal instability (P = 0.0071). Array-based comparative genomic hybridization revealed that no tumors (0%) showed BUB1B amplification and gain, indicating that overexpression of BUBR1 was independent of BUB1B copy number. For disease-specific survival, BUBR1 overexpression, lymphovascular invasion, pathological tumor stage, pathological lymph node involvement and low MSH2 expression were significant prognostic factors in univariate analyses. In multivariate analyses, BUBR1 overexpression was an independent prognostic factor for disease-specific survival (P = 0.0483, risk ratio 3.76, 95% confidence interval: 1.01-18.43).

CONCLUSIONS

BUBR1 may have significant potential as a biomarker for estimating disease-specific survival in patients with upper tract urothelial carcinoma treated by radical nephroureterectomy.

Overexpression of BUB1B contributes to progression of prostate cancer and predicts poor outcome in patients with prostate cancer

BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) is a member of the spindle assembly checkpoint protein family, which has been proven to be associated with many kinds of cancers. The aim of this study was to investigate whether BUB1B was correlated with progression and prognosis in patients with prostate cancer (PCa) and how BUB1B regulated the proliferation, migration, and invasion of PCa cell lines. Compared to benign prostate cells and tissues, both messenger RNA and protein expressions of BUB1B were statistically increased in PCa cell lines and tumor tissues. In vitro studies revealed that BUB1B overexpression enhanced the proliferation, migration, and invasion ability of PCa cell lines, whereas depletion of BUB1B did not affect the cell functions. Microarray analysis showed the positive staining of BUB1B was upregulated in the higher Gleason score group, which also correlated with advanced clinicopathological stage, higher serum prostate-specific antigen, metastasis, overall survival, and prostate-specific antigen failure. Furthermore, the survival analysis indicated that high expression of BUB1B was an independent predictor for shorter biochemical recurrence-free survival, which had no effect on overall survival. BUB1B plays an important role in tumor growth and progression, which can lead to its use as a potential biomarker for the diagnosis and prognosis of PCa.

Requirement for BUB1B/BUBR1 in tumor progression of lung adenocarcinoma

Lung adenocarcinoma is often discovered as metastatic disease with very poor prognosis. However, much remains unknown about the mechanisms of lung adenocarcinoma tumor progression. In this study we showed that knockdown of BUB1B/BUBR1, a critical mitotic checkpoint protein, significantly inhibited anchorage-independent growth of lung adenocarcinoma cell lines. In allograft and tail vein mouse model studies, BUB1B suppression inhibited primary tumor growth and reduced metastasis to the lung and lymph nodes, resulting in prolonged survival in both tumor prevention and tumor intervention settings. Mechanistic studies revealed that BUB1B knockdown sensitized cells to anoikis. The N-terminal region and GLEBS domain of BUB1B were required for its functions in both anchorage-independent growth and anoikis resistance, whereas the kinase domain was less critical. Overexpression of BUB1B is associated with disease progression and poor survival in human lung adenocarcinoma patients. Collectively, these data reveal a novel function for BUB1B in mediating anchorage-independent survival and growth, thereby facilitating lung adenocarcinoma dissemination during metastasis. Thus, targeting BUB1B could provide potential therapeutic benefit in suppressing metastasis and prolonging survival in lung adenocarcinoma patients.

TP53 immunohistochemical expression is associated with the poor outcome for hepatocellular carcinoma: evidence from a meta-analysis

Various studies examined the relationship between p53 expression with the clinical outcome in patients with hepatocellular carcinoma (HCC), but yielded conflicting results. Electronic databases updated to July 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between p53 expression and survival of patients with HCC. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of 24 studies that evaluated the correlation between p53 expression and survival in patients with HCC. Combined hazard ratios suggested that p53 expression had an unfavorable impact on overall survival (OS) (HR (hazard ratio) = 1.55, 95 % CI (confidence interval) 1.36-1.74) and disease-free survival (DFS) (HR = 1.54, 95 % CI 1.21-1.88) in patients with HCC. No significant heterogeneity was observed among 20 studies for OS (P = 0.786) and among 11 studies for DFS (P = 0.698). P53 expression indicates a poor prognosis for patients with hepatocellular carcinoma.

Prognostic significance of TP53 expression for patients with hepatocellular carcinoma: a meta-analysis

BACKGROUND

Various studies evaluated the relationship between p53 expression and the clinical outcome in patients with hepatocellular carcinoma (HCC), but yielded conflicting results.

METHODS

Electronic databases updated to Dec 2013 were searched to find relevant studies. A meta-analysis was conducted with eligible studies which quantitatively evaluated the relationship between p53 expression and survival of patients with HCC. Survival data were aggregated and quantitatively analyzed.

RESULTS

We performed a meta-analysis of 24 studies that evaluated the correlation between p53 expression and survival in patients with HCC. Combined hazard ratios (HRs) suggested that p53 expression had an unfavorable impact on overall survival (OS) [HR =1.64, 95% confidence interval (CI): 1.40-1.85], and disease free survival (DFS) (HR =1.57, 95% CI: 1.26-1.87) in patients with HCC.

CONCLUSIONS

p53 expression indicates a poor prognosis for patients with HCC.

Hepatocellular tumors: immunohistochemical analyses for classification and prognostication

Following the classification of hepatocellular nodules by the International Working Party in 1995 and further elaboration by the International Consensus Group for Hepatocellular Neoplasia in 2009, entities under the spectrum of hepatocellular nodules have been better characterized. Research work hence has been done to answer questions such as distinguishing high-grade dysplastic nodules from early hepatocellular carcinoma (HCC), delineating the tumor cell origin of HCC, identifying its prognostic markers, and subtyping hepatocellular adenomas. As a result, a copious amount of data at immunohistochemical and molecular levels has emerged. A panel of immunohistochemical markers including glypican-3, heat shock protein 70 and glutamine synthetase has been found to be of use in the diagnosis of small, well differentiated hepatocellular tumors and particularly of HCC. The use of liver fatty acid binding protein (L-FABP), β-catenin, glutamine synthetase, serum amyloid protein and C-reactive protein is found to be helpful in the subtyping of hepatocellular adenomas. The role of tissue biomarkers for prognostication in HCC and the use of biomarkers in subclassifying HCC based on tumor cell origin are also discussed.

New insights into the role of BubR1 in mitosis and beyond

BubR1 is a critical component of the spindle assembly checkpoint, the surveillance mechanism that helps maintain the high fidelity of mitotic chromosome segregation by preventing cells from initiating anaphase if one or more kinetochores are not attached to the spindle. BubR1 also helps promote the establishment of stable kinetochore-microtubule attachments during prometaphase. In this chapter, we review the structure, functions, and regulation of BubR1 in these "classical roles" at the kinetochore. We discuss its recruitment to kinetochores, its assembly into the inhibitor of anaphase progression, and the importance of its posttranslational modifications. We also consider the evidence for its participation in other roles beyond mitosis, such as the meiosis-specific processes of recombination and prophase arrest of the first meiotic division, the cellular response to DNA damage, and in the regulation of centrosome and basal body function. Finally, studies are presented linking BubR1 dysfunction or misregulation to aging and human disease, particularly cancer.

Alterations of TP53 are associated with a poor outcome for patients with hepatocellular carcinoma: evidence from a systematic review and meta-analysis

BACKGROUND

The prognostic significance of p53 aberration in hepatocellular carcinoma (HCC) remains inconclusive. This systematic review and meta-analysis aimed to provide comprehensive evidence on the association of p53 alterations with recurrence-free survival (RFS) and overall survival (OS) in HCC patients.

METHODS

Systematic literature searches were conducted until July 2010. Meta-analysis was performed to estimate prognostic effects of p53 alterations on patient outcomes in HCC. Sensitivity and subgroup analyses were also conducted in the meta-analysis.

RESULTS

Thirty-seven studies (7 tumour p53 mutation, 23 tumour p53 expression and 7 serum anti-p53 antibodies) were included in the systematic review and meta-analysis. The average percentages of p53 mutation, p53 expression upregulation and anti-p53 antibody level elevation in HCC patients were 31.5%, 35.0% and 23.8%, respectively. Tumour p53 alterations were associated significantly with poor patient outcomes in HCC: the summary hazard ratio (HR) of mutant p53 versus wild type p53 phenotype was 2.58 [95% confidence interval (CI): 1.96-3.41] for OS and 3.19 [95% CI: 2.21-4.60] for RFS, respectively; and the summary HR of upregulated p53 expression versus low/undetectable p53 expression was 1.68 [95% CI: 1.49-1.90] for OS and 1.89 [95% CI: 1.34-2.66] for RFS, respectively. However, elevated serum anti-p53 antibody was only associated with poor OS in HCC group with a high proportion of (≥ 50%) of hepatitis C virus (HCV) infection [HR: 1.92; 95% CI: 1.30-2.85]. Moreover, sensitivity analyses showed that the results of meta-analyses were not altered.

CONCLUSION

HCC patients with p53 mutation and upregulated expression in tumour tissue have a shorter OS and RFS than patients with wild type p53 and low/undetectable p53 expression. However, the prognostic value of serum anti-p53 antibody is required to be further examined.

Increased expression of ZBP-89 and its prognostic significance in hepatocellular carcinoma

AIMS

  ZBP-89 plays a role in cell growth and death. Its expression in hepatocellular carcinoma (HCC) is not well documented. This study aimed to analyse ZBP-89 expression in HCC.

METHODS AND RESULTS

  We examined ZBP-89 expression in five HCC cell lines and 182 HCC tissue samples by reverse transcription-polymerase chain reaction (RT-PCR), Western blot analysis and immunofluorescence staining. Our results showed that the expression of ZBP-89 was higher in HCC than adjacent non-tumour liver, at both mRNA and protein levels. ZBP-89 was localized in the nucleus in most HCC tissue samples, but was found in the cytoplasm in 11.5% of cases. Patient survival in those tumours showing high ZBP-89 expression was better than in those with low expression. High ZBP-89 expression tended to be more common in World Health Organization (WHO) grade I than grades II-IV HCC. There was a significant association between HBV positivity and high ZBP-89 expression. Colony formation was reduced dramatically in those HCC cell lines in which ZBP-89 overexpression was demonstrated; this appeared to correlate with increased apoptosis, inferred by finding elevated levels of cleaved poly(ADP-ribose)polymerases (PARP), the probable mechanisms for which may involve increased p53 or p21 expression.

CONCLUSIONS

  ZBP-89 has anti-tumour properties and is a potential biomarker for prognosis of HCC.

Aneuploidy and tumorigenesis

Aneuploidy is a prominent phenotype of cancer. It refers to deviations from the normal number of chromosomes in a cell, as a result of whole-chromosome loss or gain. In most cases, aneuploidy is caused by mitotic errors due to defects in the mechanisms that have evolved to ensure faithful chromosome segregation, such as the spindle assembly checkpoint (SAC). The observation that SAC-deficient mice are tumor prone demonstrates that this checkpoint is important in suppressing tumor formation and suggests that aneuploidy can induce tumorigenesis. In this review, we will summarize our current knowledge about the cause of aneuploidy and discuss the cellular response to aneuploidy in the context of tumorigenesis.

BUBR1 expression in oral squamous cell carcinoma and its relationship to tumor stage and survival

BACKGROUND

Defects in the mitotic spindle checkpoint have been proposed to contribute to the chromosomal instability observed in human cancers, including oral squamous cell carcinoma (OSCC). BUBR1 is a key component of the spindle checkpoint, whose role in oral carcinogenesis still needs to be clarified.

METHODS

We have analyzed the expression of BUBR1 in 49 cases of OSCC by immunohistochemistry and compared the findings with clinicopathologic parameters, proliferative activity, and DNA ploidy.

RESULTS

BUBR1 was overexpressed in 11 cases (22.4%). Tumors with overexpression of BUBR1 were associated with a less advanced pathologic stage (p = .05) and showed longer survival periods (p = .38) but shorter recurrence-free survival periods (p = .13) than those without it.

CONCLUSIONS

Our data imply the possibility that BUBR1 may be involved in the progression of OSCC, and suggest that BUBR1 may be a promising prognostic marker in patients with OSCC.