MCM6 promotes metastasis of hepatocellular carcinoma via MEK/ERK pathway and serves as a novel serum biomarker for early recurrence

Signaling pathways in liver cancer: pathogenesis and targeted therapy

Liver cancer remains one of the most prevalent malignancies worldwide with high incidence and mortality rates. Due to its subtle onset, liver cancer is commonly diagnosed at a late stage when surgical interventions are no longer feasible. This situation highlights the critical role of systemic treatments, including targeted therapies, in bettering patient outcomes. Despite numerous studies on the mechanisms underlying liver cancer, tyrosine kinase inhibitors (TKIs) are the only widely used clinical inhibitors, represented by sorafenib, whose clinical application is greatly limited by the phenomenon of drug resistance. Here we show an in-depth discussion of the signaling pathways frequently implicated in liver cancer pathogenesis and the inhibitors targeting these pathways under investigation or already in use in the management of advanced liver cancer. We elucidate the oncogenic roles of these pathways in liver cancer especially hepatocellular carcinoma (HCC), as well as the current state of research on inhibitors respectively. Given that TKIs represent the sole class of targeted therapeutics for liver cancer employed in clinical practice, we have particularly focused on TKIs and the mechanisms of the commonly encountered phenomena of its resistance during HCC treatment. This necessitates the imperative development of innovative targeted strategies and the urgency of overcoming the existing limitations. This review endeavors to shed light on the utilization of targeted therapy in advanced liver cancer, with a vision to improve the unsatisfactory prognostic outlook for those patients.

Investigating the Role of KLF6 in the Growth of Bovine Preadipocytes: Using Transcriptomic Analyses to Understand Beef Quality

Intramuscular fat is a crucial determinant of carcass quality traits like tenderness and taste, which in turn is influenced by the proliferation of intramuscular preadipocytes. This study aimed to investigate the Krüppel-like factor 6 (KLF6)-mediated proliferation of bovine preadipocytes and identify underlying molecular mechanisms. Down-regulation of KLF6 by siKLF6 resulted in a significant (p < 0.01) suppression of cell cycle-related genes including CDK1, MCM6, ZNF4, PCNA, CDK2, CCNB1, and CDK6. Conversely, the expression level of p27 was significantly (p < 0.01) increased. Moreover, EdU (5-ethynyl-20-deoxyuridine) staining revealed a significant decrease in EdU-labeled cells due to KLF6 down-regulation. Collectively, these findings indicate that KLF6 down-regulation inhibits adipocyte proliferation. Furthermore, RNA sequencing of preadipocytes transfected with siKLF6 and NC, followed by differential gene expression analysis, identified 100 up-regulated and 70 down-regulated genes. Additionally, the differentially expressed genes also significantly influenced various Gene Ontology (GO) terms related to cell cycle, nuclear chromosomes, and catalytic activity on DNA. Furthermore, the top 20 pathways enriched in these DEGs included cell cycle, DNA replication, cellular senescence, and homologous recombination. These GO terms and KEGG pathways play key roles in bovine preadipocyte proliferation. In conclusion, the results of this study suggest that KLF6 positively regulates the proliferation of bovine preadipocytes.

ACAT1 promotes proliferation and metastasis of bladder cancer via AKT/GSK3β/c-Myc signaling pathway

Acetyl-CoA acetyltransferase 1 (ACAT1) plays a significant role in the regulation of gene expression and tumorigenesis. However, the biological role of ACAT1 in bladder cancer (BLCA) has yet to be elucidated. This research aimed to elucidate the bioinformatics features and biological functions of ACAT1 in BLCA. Here, we demonstrate that ACAT1 is elevated in BLCA tissues and is correlated with specific clinicopathological features and an unfavorable prognosis for survival in BLCA patients. ACAT1 was identified as an independent risk factor in BLCA. Phenotypically, both in vitro and in vivo, ACAT1 knockdown suppressed BLCA cell proliferation and migration, while ACAT1 overexpression had the opposite effect. Mechanistic assays revealed that ACAT1 enhances BLCA cell proliferation and metastasis through the AKT/GSK3β/c-Myc signaling pathway by modulating the cell cycle and EMT. Taken together, the results of our study reveal that ACAT1 is an oncogenic driver in BLCA that enhances tumor proliferation and metastasis, indicating its potential as a diagnostic and therapeutic target for this disease.

Systematic analysis of expression and prognostic significance for MCM family in head and neck squamous cell carcinoma

BACKGROUND

Head and neck squamous cell carcinoma (HNSC) is a common malignant tumor in the world and has a poor prognosis. The family of minichromosome maintenance proteins (MCM) improves the stability of genome replication by inhibiting the rate of DNA replication in eukaryotic cells, thus, small changes in physiological MCM levels would increase the instability of gene replication and increase the incidence of tumor formation, most of which are significantly elevated in multiple cancers. However, the expression of different MCM families in HNSC and their prognostic value remain unclear.

METHODS

ONCOMINE and GEPIA databases were used to analyze the expression of MCMs in HNSC. The Kaplan-Meier plotter database was used to identify molecules with prognostic values. We collected 77 HNSC tissues and 50 normal tissues to validate the results of the bioinformatics analysis by immunohistochemical staining.

RESULTS

The expression of MCM3, MCM5 and MCM6 in mRNA and protein levels were higher in HNSC. Moreover, the increased expression of MCM3, MCM5 and MCM6 in mRNA and protein levels predicted better prognosis of HNSC patients. Furthermore, multivariate analysis showed that high expressions of MCM3, MCM5 and MCM6 in protein level may be independent prognostic factors for HNSC patients.

CONCLUSION

The results of this study indicated that MCM3, MCM5 and MCM6 play an important role in occurrence and development in HNSC and might be risk factors for the survival of HNSC patients.

RNF125‑mediated ubiquitination of MCM6 regulates the proliferation of human liver hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated mortality worldwide. Minichromosome maintenance proteins (MCMs), particularly MCM2-7, are upregulated in various cancers, including HCC. The aim of the present study was to investigate the role of MCM2-7 in human liver HCC (LIHC) and the regulation of the protein homeostasis of MCM6 by a specific E3 ligase. Bioinformatics analyses demonstrated that MCM2-7 were highly expressed in LIHC compared with corresponding normal tissues at the mRNA and protein levels, and patients with LIHC and high mRNA expression levels of MCM2, MCM3, MCM6 and MCM7 had poor overall survival rates. Cell Counting Kit-8 and colony formation assays revealed that the knockdown of MCM2, MCM3, MCM6 or MCM7 in Huh7 and Hep3B HCC cells inhibited cell proliferation and colony formation. In addition, pull-down, co-immunoprecipitation and ubiquitination assays demonstrated that RNF125 interacts with MCM6 and mediates its ubiquitination. Furthermore, co-transfection experiments indicated that RNF125 promoted the proliferation of HCC cells mainly through MCM6. In summary, the present study suggests that the RNF125-MCM6 axis plays an important role in the regulation of HCC cell proliferation and is a promising therapeutic target for the treatment of LIHC.

Heterogeneous Expression Patterns of the Minichromosome Maintenance Complex Members in Retinoblastoma Unveil Its Clinical Significance

Purpose

To explore the expression patterns and clinical significance of minichromosome maintenance (MCM) complex members in retinoblastoma (RB).

Methods

Single-cell RNA sequencing datasets from five normal retina, six intraocular, and five extraocular RB samples were integrated to characterize the expression patterns of MCM complex members at the single-cell level. Western blot and quantitative PCR were used to detect the expression of MCM complex members in RB cell lines. Immunohistochemistry was conducted to validate the expression of MCM complex members in RB patient samples and a RB mouse model.

Results

The expression of MCM2-7 is increased in RB tissue, with MCM2/3/7 showing particularly higher levels in extraocular RB. MCM3/7 are abundantly detected in cell types associated with oncogenesis. Both mRNA and protein levels of MCM3/4/6/7 are increased in RB cell lines. Immunohistochemistry further confirmed the elevated expression of MCM3 in extraocular RB, with MCM6 being the most abundantly expressed MCM in RB.

Conclusions

The distinct MCM expression patterns across various RB cell types suggest diverse functional roles, offering valuable insights for targeted therapeutic strategies. The upregulation of MCM3, MCM4, MCM6, and MCM7 in RB, with a specific emphasis on MCM6 as a notable marker, highlights their potential significance.

Two-Dimensional-PAGE Coupled with nLC-MS/MS-Based Identification of Differentially Expressed Proteins and Tumorigenic Pathways in MCF7 Breast Cancer Cells Transfected for JTB Protein Silencing

The identification of new cancer-associated genes/proteins, the characterization of their expression variation, the interactomics-based assessment of differentially expressed genes/proteins (DEGs/DEPs), and understanding the tumorigenic pathways and biological processes involved in BC genesis and progression are necessary and possible by the rapid and recent advances in bioinformatics and molecular profiling strategies. Taking into account the opinion of other authors, as well as based on our own team's in vitro studies, we suggest that the human jumping translocation breakpoint (hJTB) protein might be considered as a tumor biomarker for BC and should be studied as a target for BC therapy. In this study, we identify DEPs, carcinogenic pathways, and biological processes associated with JTB silencing, using 2D-PAGE coupled with nano-liquid chromatography tandem mass spectrometry (nLC-MS/MS) proteomics applied to a MCF7 breast cancer cell line, for complementing and completing our previous results based on SDS-PAGE, as well as in-solution proteomics of MCF7 cells transfected for JTB downregulation. The functions of significant DEPs are analyzed using GSEA and KEGG analyses. Almost all DEPs exert pro-tumorigenic effects in the JTBlow condition, sustaining the tumor suppressive function of JTB. Thus, the identified DEPs are involved in several signaling and metabolic pathways that play pro-tumorigenic roles: EMT, ERK/MAPK, PI3K/AKT, Wnt/β-catenin, mTOR, C-MYC, NF-κB, IFN-γ and IFN-α responses, UPR, and glycolysis/gluconeogenesis. These pathways sustain cancer cell growth, adhesion, survival, proliferation, invasion, metastasis, resistance to apoptosis, tight junctions and cytoskeleton reorganization, the maintenance of stemness, metabolic reprogramming, survival in a hostile environment, and sustain a poor clinical outcome. In conclusion, JTB silencing might increase the neoplastic phenotype and behavior of the MCF7 BC cell line. The data is available via ProteomeXchange with the identifier PXD046265.

Minichromosome maintenance 6 protects against renal fibrogenesis by regulating DUSP6-mediated ERK/GSK-3β/Snail1 signaling

Minichromosome maintenance 6 (MCM6) has been implicated in the progression of various malignant tumors; however, its exact physiological function in kidney diseases remains unclear. Here, we demonstrated that MCM6 levels showed a significant increase in the proximal tubular cells during progressive renal fibrosis in two unrelated in vivo fibrotic models, including unilateral ureteral obstruction (UUO) and unilateral ischemia-reperfusion injury (UIRI). Depletion of MCM6 aggravated partial epithelial-mesenchymal transition, extracellular matrix accumulation, and myofibroblast activation in the kidneys of UUO or UIRI mice. Conversely, overexpression of MCM6 promoted the recovery of E-cadherin and retarded UUO- or UIRI-induced renal fibrosis. In addition, DUSP6 expression substantially decreased in fibrotic kidneys, and it might be involved in MCM6-induced renal fibrosis by regulating the activation of ERK/GSK-3β/Snail1 signaling. In conclusion, our results highlight the significance of MCM6 in renal fibrosis, providing a potential therapeutic target for patients with chronic kidney disease.

MCM6 promotes intrahepatic cholangiocarcinoma progression by upregulating E2F1 and enhancing epithelial-mesenchymal transition

Minichromosome maintenance complex component 6 (MCM6), a member of the MCM family, plays a pivotal role in DNA replication initiation and genome duplication of proliferating cells. MCM6 is upregulated in multiple malignancies and is considered a novel diagnostic biomarker. However, the functional contributions and prognostic value of MCM6 in intrahepatic cholangiocarcinoma (ICC) remain unexplored. In this study, we investigated the molecular function of MCM6 in ICC. Data from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO, GSE107943) indicated an upregulation of MCM6 in tumor tissues. Immunohistochemical analysis performed on 115 cases of ICC samples confirmed the upregulation of MCM6 and further suggested that a high level of MCM6 expression predicted shorter overall and disease-free survival in ICC patients. Functional studies suggested that MCM6 knockdown significantly suppressed cell viability, blocked cell cycle progression and inhibited metastasis, while the enhancement of MCM6 expression promoted the proliferation and migration of ICC cells both in vitro and in vivo. Mechanistically, Gene Set Enrichment Analysis (GSEA) suggested that the epithelial-mesenchymal transition (EMT) and E2F1-correlated genes were enriched in ICC tissues with high MCM6 expression. Further verification indicated that MCM6 promoted the EMT of ICC cells via upregulating E2F1. In addition, E2F1 knockdown partially blocked the pro-malignant effects of MCM6 overexpression. In summary, MCM6 was found to be a novel prognostic and predictive marker for ICC. MCM6 promoted ICC progression via activation of E2F1-mediated EMT.

Lysyl hydroxylase LH1 promotes confined migration and metastasis of cancer cells by stabilizing Septin2 to enhance actin network

BACKGROUND

Excessive extracellular matrix deposition and increased stiffness are typical features of solid tumors such as hepatocellular carcinoma (HCC) and pancreatic ductal adenocarcinoma (PDAC). These conditions create confined spaces for tumor cell migration and metastasis. The regulatory mechanism of confined migration remains unclear.

METHODS

LC-MS was applied to determine the differentially expressed proteins between HCC tissues and corresponding adjacent tissue. Collective migration and single cell migration microfluidic devices with 6 μm-high confined channels were designed and fabricated to mimic the in vivo confined space. 3D invasion assay was created by Matrigel and Collagen I mixture treat to adherent cells. 3D spheroid formation under various stiffness environment was developed by different substitution percentage GelMA. Immunoprecipitation was performed to pull down the LH1-binding proteins, which were identified by LC-MS. Immunofluorescent staining, FRET, RT-PCR, Western blotting, FRAP, CCK-8, transwell cell migration, wound healing, orthotopic liver injection mouse model and in vivo imaging were used to evaluate the target expression and cellular phenotype.

RESULTS

Lysyl hydroxylase 1 (LH1) promoted the confined migration of cancer cells at both collective and single cell levels. In addition, LH1 enhanced cell invasion in a 3D biomimetic model and spheroid formation in stiffer environments. High LH1 expression correlated with poor prognosis of both HCC and PDAC patients, while it also promoted in vivo metastasis. Mechanistically, LH1 bound and stabilized Septin2 (SEPT2) to enhance actin polymerization, depending on the hydroxylase domain. Finally, the subpopulation with high expression of both LH1 and SEPT2 had the poorest prognosis.

CONCLUSIONS

LH1 promotes the confined migration and metastasis of cancer cells by stabilizing SEPT2 and thus facilitating actin polymerization.

A High MCM6 Proliferative Index in Atypical Meningioma Is Associated with Shorter Progression Free and Overall Survivals

The aim of this study was to evaluate the prognostic value of MCM6, in comparison with Ki-67, in two series of grade 1 and 2 meningiomas, and to evaluate its correlation with methylation classes. The first cohort included 100 benign (grade 1, World Health Organization 2021) meningiomas, and the second 69 atypical meningiomas (grade 2). Immunohistochemical Ki-67 and MCM6 labeling indices (LI) were evaluated independently by two observers. Among the atypical meningiomas, 33 cases were also studied by genome-wide DNA methylation. In grade 2 meningiomas, but not grade 1, both Ki-67 and MCM6 LIs were correlated with PFS (p = 0.004 and p = 0.005, respectively; Cox univariate analyses). Additionally, MCM6 was correlated with overall survival only in univariate analysis. In a multivariate model, including mitotic index, Ki-67, MCM6, age, sex, and the quality of surgical resection, only MCM6 was correlated with PFS (p = 0.046). Additionally, we found a significant correlation between PTEN loss and high MCM6 or Ki-67 LIs. Although no correlation was found with the methylation classes and subtypes returned by the meningioma algorithm MNGv2.4., MCM6 LI was significantly correlated with the methylation of 2 MCM6 gene body loci. In conclusion, MCM6 is a relevant prognostic marker in atypical meningiomas. This reproducible and easy-to-use marker allows the identification of a highly aggressive subtype of proliferative meningiomas, characterized notably by frequent PTEN losses, which was previously reported to be sensitive to histone deacetylase inhibitors.

IMP4 Silencing Inhibits the Malignancy of Lung Adenocarcinoma via ERK Pathway

Our study aimed to elucidate the function of IMP U3 small nucleolar ribonucleoprotein 4 (IMP4) in lung adenocarcinoma (LUAD) and its potential molecular mechanisms. Cell counting kit-8, 5-ethynyl-20-deoxyuridine, flow cytometry, wound healing, and transwell assays were performed to examine the biological behaviour of LUAD cells. mRNA and protein expression levels were determined using quantitative real-time PCR, Western blotting, and immunohistochemistry. In addition, a mouse tumour xenograft model was used to evaluate the role of IMP4 in tumour progression. Furthermore, glycolysis-related indicators were measured. The levels of IMP4 were up-regulated in both human LUAD tissues and cells. IMP4 silencing significantly suppressed proliferation, migration, invasion, and glycolysis; promoted apoptosis; and induced cell cycle arrest in LUAD cells. IMP4 silencing also inactivated the extracellular signal-regulated kinase (ERK) pathway. Moreover, rescue experiments demonstrated that the function of LUAD cells induced by IMP4 overexpression could be reversed by treatment with an ERK pathway inhibitor (SCH772984). In vivo experiments further verified that IMP4 silencing repressed the growth of subcutaneous tumours and glycolysis. IMP4 silencing suppressed the malignancy of LUAD by inactivating ERK signalling.

Construction and validation of a prognostic marker and risk model for HCC ultrasound therapy combined with WGCNA identification

Background: Hepatocellular carcinoma (HCC) is a malignant tumor with a highly aggressive and metastatic nature. Ultrasound remains a routine monitoring tool for screening, treatment and post-treatment recheck of HCC. Therefore, it is of great significance to explore the role of ultrasound therapy and related genes in prognosis prediction and clinical diagnosis and treatment of HCC.

Methods: Gene co-expression networks were developed utilizing the R package WGCNA as per the expression profiles and clinical features of TCGA HCC samples, key modules were identified by the correlation coefficients between clinical features and modules, and hub genes of modules were determined as per the GS and MM values. Ultrasound treatment differential expression genes were identified using R package limma, and univariate Cox analysis was conducted on the intersection genes of ultrasound differential expression genes and hub genes of key HCC modules to screen the signatures linked with HCC prognosis and construct a risk model. The median risk score was used as the threshold point to classify tumor samples into high- and low-risk groups, and the R package IOBR was used to assess the proportion of immune cells in high- and low-risk groups, R package maftools to assess the genomic mutation differences in high- and low-risk groups, R package GSVA’s ssgsea algorithm to assess the HALLMARK pathway enrichment analysis, and R package pRRophetic to analyze drug sensitivity in patients with HCC.

Results: WGCNA analysis based on the expression profiles and clinical data of the TCGA LIHC cohort identified three key modules with two major clinical features associated with HCC. The intersection of ultrasound-related differential genes and module hub genes was selected for univariate Cox analysis to identify prognostic factors significantly associated with HCC, and a risk score model consisting of six signatures was finally developed to analyze the prognosis of individuals with HCC. The risk model showed strength in the training set, overall set, and external validation set. The percentage of immune cell infiltration, genomic mutations, pathway enrichment scores, and chemotherapy drug resistance were significantly different between high- and low-risk groups according to the risk scores. Expression of model genes correlated with tumor immune microenvironment and clinical tumor characteristics while generally differentially expressed in pan-cancer tumor and healthy samples. In the immunotherapy dataset, patients in the high-risk group had a worse prognosis with immunotherapy, indicating that subjects in the low-risk group are more responsive to immunotherapy.

Conclusion: The 6-gene signature constructed by ultrasound treatment of HCC combined with WGCNA analysis can be used for prognosis prediction of HCC patients and may become a marker for immune response.

Heterogeneity, inherent and acquired drug resistance in patient-derived organoid models of primary liver cancer

PURPOSE

We aimed to elucidate the applicability of tumor organoids for inherent drug resistance of primary liver cancer (PLC) and mechanisms of acquired drug resistance.

METHODS

PLC tissues were used to establish organoids, organoid-derived xenograft (ODX) and patient-derived xenograft (PDX) models. Acquired drug resistance was induced in hepatocellular carcinoma (HCC) organoids. Gene expression profiling was performed by RNA-sequencing.

RESULTS

Fifty-two organoids were established from 153 PLC patients. Compared with establishing PDX models, establishing organoids of HCC showed a trend toward a higher success rate (29.0% vs. 23.7%) and took less time (13.0 ± 4.7 vs. 25.1 ± 5.4 days, p = 2.28 × 10^-13). Larger tumors, vascular invasion, higher serum AFP levels, advanced stages and upregulation of stemness- and proliferation-related genes were significantly associated with the successful establishment of HCC organoids and PDX. Organoids and ODX recapitulated PLC histopathological features, but were enriched in more aggressive cell types. PLC organoids were mostly resistant to lenvatinib in vitro but sensitive to lenvatinib in ODX models. Stemness- and epithelial-mesenchymal transition (EMT)-related gene sets were found to be upregulated, whereas liver development- and liver specific molecule-related gene sets were downregulated in acquired sorafenib-resistant organoids. Targeting the mTOR signaling pathway was effective in treating acquired sorafenib-resistant HCC organoids, possibly via inducing phosphorylated S6 kinase. Genes upregulated in acquired sorafenib-resistant HCC organoids were associated with an unfavorable prognosis.

CONCLUSIONS

HCC organoids perform better than PDX for drug screening. Acquired sorafenib resistance in organoids promotes HCC aggressiveness via facilitating stemness, retro-differentiation and EMT. Phosphorylated S6 kinase may be predictive for drug resistance in HCC.

MCM6 Promotes Hepatocellular Carcinoma Progression via the Notch Pathway: Clinical, Functional, and Genomic Insights

Objective

To evaluate the expression profile of MCM6 in HCC and the relationship between MCM6 level and clinicopathological parameters through bioinformatics analysis of several databases.

Methods

MCM expression level, clinical parameters, survival data, and gene set enrichment analysis were analyzed by bioinformatics database, including Oncomine™, UALCAN, HCCDB, TCGA, cBioPortal, and LinkedOmics. Real-time PCR, western blotting, and IHC staining were conducted to identify the expression of MCM6 in HCC compared to normal liver tissues.

Results

Bioinformatics analysis indicated that the mRNA of MCM6 was obviously increased in multiple cancer types, especially in HCC. MCM6 level was positively associated with multiple clinical parameters (stage 3 and grades 3 and 4) and negatively associated with patient outcomes (overall survival). Moreover, enrichment of functions and signaling pathways analysis of MCM6 suggested that MCM6 might mediate DNA replication and cellular metabolism to promote the development and progression of HCC. Furthermore, IHC staining and western blotting indicated that the MCM6 was enhanced in HCC tissue, and MCM6 could promote HCC proliferation in activating Notch pathway via WB and bioinformatic analysis.

Conclusion

This study actually revealed the expression and related functions of MCM6 in HCC. Furthermore, MCM6 is a carcinogenic role in activating Notch pathway to promote HCC cell proliferation, which may be a new prognostic biomarker and therapeutic target for HCC patients.

Bioinformatic Analysis of the Expression and Clinical Significance of the DNA Replication Regulator MCM Complex in Bladder Cancer

Objective

The minichromosome maintenance (MCM) complex (MCM2, MCM3, MCM4, MCM5, MCM6, and MCM7), which regulates DNA replication and cell cycle progression, is essential for the development and progression of multiple tumors, but their role in bladder cancer development remains unclear. In the present study, the biological role and clinical significance of the MCM complex in bladder cancer were systematically elucidated.

Materials and Methods

We analyzed DNA mutations, mRNA expression and protein levels, protein–protein interaction (PPI) networks, functional enrichment, prognostic value of MCM2/3/4/5/6/7 in bladder urothelial carcinoma (BLC) and the connections between the immune cell infiltration and the overall survival of BLC patients with the MCM expression levels using Oncomine, Gene Expression Profiling Interactive Analysis (GEPIA), the Cancer Genome Atlas database (TCGA), Human Protein Atlas, UALCAN, STRING, cBioPortal, TIMER and GSCALite databases.

Results

The outcomes showed that the mRNA expression level of each member of the MCM complex was significantly correlated with histologic grade and tumor histology in BLC patients. Moreover, survival analysis showed that MCM/2/3/4/5/6/7 mRNA expressions were significantly associated with prognosis in patients with bladder cancer. Moreover, we experimentally validated the overexpression of the MCM2-7 complex in the BLC. Based on functional enrichment and PPI network analysis, the MCM complex might promote the progression of bladder cancer by activating DNA replication and accelerating cell cycle progression. In addition, MCM2/3/4/5/6/7 genes were also significantly associated with tumor immune cells infiltration and the drug sensitivity in BLC.

Conclusion

Our study suggests that the MCM complex especially MCM2/4/6/7 might be potential molecular therapeutic targets for BLC treatment and might be useful biomarkers for diagnosis and prognosis.

Identification of a 5-Nutrient Stress-Sensitive Gene Signature to Predict Survival for Colorectal Cancer

Background

The high heterogeneity and the complexity of the tumor microenvironment of colorectal cancer (CRC) have enhanced the difficulty of prognosis prediction based on conventional clinical indicators. Recent studies revealed that tumor cells could overcome various nutritional deficiencies by gene regulation and metabolic remodeling. However, whether differentially expressed genes (DEGs) in CRC cells under kinds of nutrient deficiency could be used to predict prognosis remained unveiled.

Methods

Three datasets (GSE70976, GSE13548, and GSE116087), in which colon cancer cells were, respectively, cultured in serum-free, glucose-free, or glutamine-free medium, were included to delineate the profiles of gene expression by nutrient stress. DEGs were figured out in three datasets, and gene functional analysis was performed. Survival analyses and Cox proportional hazards model were then used to identify nutrient stress sensitive genes in CRC datasets (GSE39582 and TCGA COAD). Then, a 5-gene signature was constructed and the risk scores were also calculated. Survival analyses, cox analyses, and nomogram were applied to predict the prognosis of patients with colorectal cancer. The effectiveness of the risk model was also tested.

Results

A total of 48 genes were found to be dysregulated in serum, glucose, or glutamine-deprived CRC cells, which were mainly enriched in cell cycle and endoplasmic reticulum stress pathways. After further analyses, 5 genes, MCM5, MCM6, CDCA2, GINS2, and SPC25, were identified to be differentially expressed in CRC and be related to prognosis of in CRC datasets. We used the above nutrient stress-sensitive genes to construct a risk scoring model. CRC samples in the datasets were divided into low-risk and high-risk groups. Data showed that higher risk scores were associated with better outcomes and risk scores decreased significantly with tumor procession. Moreover, the risk score could be used to predict the probability of survival based on nomogram.

Conclusions

The 5-nutrient stress-sensitive gene signature could act as an independent biomarker for survival prediction of CRC patients.

The identification and preliminary study of lncRNA TUG1 and its related genes in hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is a common malignant tumour of the digestive system, which is a threat to public health. The purpose of this study was to investigate the featured genes and pathways of HCC from a bioinformatics database, and verify their correlation with diagnosis and prognosis of HCC.

MATERIAL AND METHODS

We downloaded the gene expression profile on HCC from the Gene Expression Omnibus (GEO), and software R was used to identify differentially expressed lncRNA (DEL). The target genes of the lncRNA were further predicted by using a cluster database and molecular interaction database. Subsequently, a combined interaction network of target genes was constructed using the Cytoscape platform with preliminary verification at the level of different databases, cell lines, and tissues. Finally, we explored the effectiveness of TUG1 and its target genes on the diagnosis and prognosis of HCC by univariate Cox analysis and survival analysis.

RESULTS

A total of four DELs were identified and the most remarkably up-regulated lncRNA was TUG1, which included 12 high-confidence target genes. Moreover, we found that the expression changes of TUG1 and its target genes in different databases, cell lines, and liver cancer tissues were consistent with the prediction. The high expression of TUG1 and its target genes could significantly predict the shorter survival time of HCC patients, among which NCAPG, MCM6, PIGC, PEA15, and RACGAP1 have significant diagnostic value for HCC (AUC > 0.9).

CONCLUSIONS

This study provides a starting point for the screening of therapeutically relevant targets in HCC. Further experiment should be conducted to verify our findings.

Prognostic significance of MCM6 expression in gastrointestinal stromal tumor

Minichromosome maintenance (MCM) proteins are essential for the initiation of DNA replication and they are prognostic markers in various human cancers. The aim of this study was to investigate the role of the MCM6 protein in gastrointestinal stromal tumor (GIST) and its clinical and prognostic significance. We evaluated MCM6 expression in 211 GIST samples using immunohistochemistry. We used the receiver operating characteristic curve (ROC) to identify optimal cut-off values. High MCM6 expression was associated with tumor size, mitosis, tumor necrosis, presence of recurrence/metastasis, and the National Institute of Health (NIH) and Armed Forces Institute of Pathology (AFIP) malignant risk criteria. Patients with high MCM6 expression had significantly shorter overall survival (OS) and disease-free survival (DFS) than those with low MCM6 expression. Univariate analysis indicated that tumor size, mitosis, AFIP and NIH malignant risk criteria, and high MCM6 expression were significantly associated with poor OS and DFS. High MCM6 expression and high-risk group categorization based on the NIH criteria were independent prognostic factors for OS and DFS. High MCM6 expression is significantly associated with tumor progression and aggressiveness and is an independent factor for shorter survival in GIST patients. MCM6 expression could be a predictive biomarker for tumor aggressiveness as well as a treatment target.

Kinesin family member 2C promotes hepatocellular carcinoma growth and metastasis via activating MEK/ERK pathway

The current work was intended to explore the function and mechanism of Kinesin family member 2C (KIF2C) in hepatocellular carcinoma (HCC). In this study, KIF2C expression was at a high level in HCC and indicated poor prognosis. Silencing KIF2C significantly suppressed the proliferation, migration, and invasion in HCC cells. Furthermore, silencing KIF2C markedly decreased the expression of Snail, Vimentin, p-MEK, and p-ERK, but increased E-cadherin expression in HCC cells. Moreover, we also found that MEK/ERK inhibitor U0126 could enhance the impact on cell proliferation, migration, and invasion induced by silencing KIF2C in HCC. On the contrary, MEK/ERK activator PAF could weaken the impact induced by silencing KIF2C in HCC. Thus, our findings indicate that KIF2C can promote the proliferation, migration, and invasion by activating MEK/ERK pathway in HCC.

Genetic determinants of blood-cell traits influence susceptibility to childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Despite overlap between genetic risk loci for ALL and hematologic traits, the etiological relevance of dysregulated blood-cell homeostasis remains unclear. We investigated this question in a genome-wide association study (GWAS) of childhood ALL (2,666 affected individuals, 60,272 control individuals) and a multi-trait GWAS of nine blood-cell indices in the UK Biobank. We identified 3,000 blood-cell-trait-associated (p < 5.0 × 10-8) variants, explaining 4.0% to 23.9% of trait variation and including 115 loci associated with blood-cell ratios (LMR, lymphocyte-to-monocyte ratio; NLR, neutrophil-to-lymphocyte ratio; PLR, platelet-to-lymphocyte ratio). ALL susceptibility was genetically correlated with lymphocyte counts (rg = 0.088, p = 4.0 × 10-4) and PLR (rg = -0.072, p = 0.0017). In Mendelian randomization analyses, genetically predicted increase in lymphocyte counts was associated with increased ALL risk (odds ratio [OR] = 1.16, p = 0.031) and strengthened after accounting for other cell types (OR = 1.43, p = 8.8 × 10-4). We observed positive associations with increasing LMR (OR = 1.22, p = 0.0017) and inverse effects for NLR (OR = 0.67, p = 3.1 × 10-4) and PLR (OR = 0.80, p = 0.002). Our study shows that a genetically induced shift toward higher lymphocyte counts, overall and in relation to monocytes, neutrophils, and platelets, confers an increased susceptibility to childhood ALL.

Epigenetic modifications precede molecular alterations and drive human hepatocarcinogenesis

Development of primary liver cancer is a multi-stage process. Detailed understanding of sequential epigenetic alterations is largely missing. Here, we performed Infinium Human Methylation 450k BeadChips and RNA sequencing analyses for genome-wide methylome and transcriptome profiling of cirrhotic liver (n=7), low- (n=4) and high-grade (n=9) dysplastic lesions, early (n=5) and progressed (n=3) hepatocellular carcinomas (HCC) synchronously detected in eight HCC patients with chronic hepatitis B infection. Integrative analyses of epigenetically driven molecular changes were identified and validated in two independent cohorts comprising 887 HCC. Mitochondrial DNA sequencing was further employed for clonality analyses and indicates multi-clonal origin in the majority of investigated HCC. Alterations in DNA methylation progressively increased from CL to dysplastic lesions and reached a maximum in early HCC. Associated early alterations identified by IPA pathway analyses involved apoptosis, immune regulation and stemness pathways, while late changes centered on cell survival, proliferation and invasion. We further validated putative 23 epi-drivers with concomitant expression changes and associated with overall survival. Functionally, Striatin 4 (STRN4) was demonstrated to be epigenetically regulated and inhibition of STRN4 significantly suppressed tumorigenicity of HCC cell lines.Overall, application of integrative genomic analyses defines epigenetic driver alterations and provides promising targets for novel therapeutic approaches.

Prognostic significance and function of MCM10 in human hepatocellular carcinoma

Aim: To investigate the role of MCM10, a conserved replication factor, in hepatocellular carcinoma (HCC). Methods: We used data from 364 HCC patients in the Cancer Genome Atlas database and conducted in vitro experiments to confirm the role of MCM10. Results: High MCM10 expression correlated with poor HCC patient outcome and was an independent prognosticator for HCC. Time-dependent receiver operating characteristic curve analysis found that the sequential trend of MCM10 for survival was not inferior to that of the tumor node metastasis stage. The MCM10 model had a higher C-index than the non-MCM10 model, indicating that incorporating MCM10 into a multivariate model improves the model's prognostic accuracy for HCC. Genetic alterations of MCM10 prominently correlated with an unfavorable HCC outcome. Conclusion: Our findings strongly suggest using the MCM10 gene as a prognostic indicator in HCC.

MCM2-7 complex is a novel druggable target for neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer that rarely develops de novo in primary tumors and is commonly acquired during the development of treatment resistance. NEPC is characterized by gain of neuroendocrine markers and loss of androgen receptor (AR), making it resistant to current therapeutic strategies targeting the AR signaling axis. Here, we report that MCM2, MCM3, MCM4, and MCM6 (MCM2/3/4/6) are elevated in human NEPC and high levels of MCM2/3/4/6 are associated with liver metastasis and poor survival in prostate cancer patients. MCM2/3/4/6 are four out of six proteins that form a core DNA helicase (MCM2-7) responsible for unwinding DNA forks during DNA replication. Inhibition of MCM2-7 by treatment with ciprofloxacin inhibits NEPC cell proliferation and migration in vitro, significantly delays NEPC tumor xenograft growth, and partially reverses the neuroendocrine phenotype in vivo. Our study reveals the clinical relevance of MCM2/3/4/6 proteins in NEPC and suggests that inhibition of MCM2-7 may represent a new therapeutic strategy for NEPC.

High MCM6 Expression as a Potential Prognostic Marker in Clear-cell Renal Cell Carcinoma

AIM

Minichromosome maintenance (MCM) proteins are involved in initiation of DNA replication and cell-cycle progression. Loss of MCM function results in genomic instability and causes carcinogenesis. Among MCM genes, the role and prognostic value of MCM6 expression in clear-cell renal cell carcinoma (ccRCC) has not been elucidated.

MATERIALS AND METHODS

We assessed the mRNA expression level of MCM6 using the Gene Expression Profiling Interactive Analysis database and investigated MCM6 protein expression by immunohistochemistry in 238 ccRCC cases.

RESULTS

High MCM6 expression was significantly associated with increasing tumor size, pT, stage, tumor necrosis, and metastasis. Furthermore, high MCM6 expression was significantly associated with shorter overall and disease-free survival, and was an independent unfavorable prognostic marker. Regarding patients with metastasis, high MCM6-expressing ccRCC conferred significantly shorter survival than for those with low expression.

CONCLUSION

A high MCM6 expression level may be a promising biomarker to predict tumor progression, metastasis, and survival in patients with ccRCC.

High copy number variations, particular transcription factors, and low immunity contribute to the stemness of prostate cancer cells

Background

Tumor metastasis is the main cause of death of cancer patients, and cancer stem cells (CSCs) is the basis of tumor metastasis. However, systematic analysis of the stemness of prostate cancer cells is still not abundant. In this study, we explore the effective factors related to the stemness of prostate cancer cells by comprehensively mining the multi-omics data from TCGA database.

Methods

Based on the prostate cancer transcriptome data in TCGA, gene expression modules that strongly relate to the stemness of prostate cancer cells are obtained with WGCNA and stemness scores. Copy number variation of stemness genes of prostate cancer is calculated and the difference of transcription factors between prostate cancer and normal tissues is evaluated by using CNV (copy number variation) data and ATAC-seq data. The protein interaction network of stemness genes in prostate cancer is constructed using the STRING database. Meanwhile, the correlation between stemness genes of prostate cancer and immune cells is analyzed.

Results

Prostate cancer with higher Gleason grade possesses higher cell stemness. The gene set highly related to prostate cancer stemness has higher CNV in prostate cancer samples than that in normal samples. Although the transcription factors of stemness genes have similar expressions, they have different contributions between normal and prostate cancer tissues; and particular transcription factors enhance the stemness of prostate cancer, such as PUM1, CLOCK, SP1, TCF12, and so on. In addition, the lower tumor immune microenvironment is conducive to the stemness of prostate cancer. CD8 + T cells and M1 macrophages may play more important role in the stemness of prostate cancer than other immune cells in the tumor microenvironment. Finally, EZH2 is found to play a central role in stemness genes and is negatively correlated with resting mast cells and positively correlated with activated memory CD4 + T cells.

Conclusions

Based on the systematic and combined analysis of multi-omics data, we find that high copy number variation, specific transcription factors, and low immune microenvironment jointly contribute to the stemness of prostate cancer cells. These findings may provide us new clues and directions for the future research on stemness of prostate cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02870-x.

Methylation-dependent MCM6 repression induced by LINC00472 inhibits triple-negative breast cancer metastasis by disturbing the MEK/ERK signaling pathway

Long noncoding RNAs (lncRNAs) have been identified to be dysregulated in multiple cancer types, which are speculated to be of vital significance in regulating several hallmarks of cancer biology. Triple-negative breast cancer (TNBC) is acknowledged as an aggressive subtype of breast cancer. In this study, we found the lncRNA LINC00472 was poorly expressed in TNBC tissues and cells. Overexpression of LINC00472 could inhibit the proliferation, invasion and migration of MDA-MB-231 cells. On the contrary, minichromosome maintenance complex component 6 (MCM6) was highly expressed in TNBC tissues and MDA-MB-231 cells due to suppressed methylation. LINC00472 induced site-specific DNA methylation and reduced the MCM6 expression by recruiting DNA methyltransferases into the MCM6 promoter. Since the restoration of MCM6 weakened the tumor-suppressive effect of LINC00472 on MDA-MB-231 cells, LINC00472 potentially acted as a tumor suppressor by inhibiting MCM6. In addition, in vivo experiments further substantiated that overexpression of LINC00472 inhibited tumor growth and metastasis to lungs by decreasing the expression of MCM6. Overall, the present study demonstrated that LINC00472-mediated epigenetic silencing of MCM6 contributes to the prevention of tumorigenesis and metastasis in TNBC, providing an exquisite therapeutic target for TNBC.

The DNA replication regulator MCM6: An emerging cancer biomarker and target

MCM6 is a significant DNA replication regulator that plays a crucial role in sustaining the cell cycle. In many cancer cells, MCM6 expression is enhanced. For example, persistently increased expression of MCM6 promotes the formation, development and progression of hepatocellular carcinoma (HCC). Up- and down-regulation studies have indicated that MCM6 regulates cell cycle, proliferation, metastasis, immune response and the maintenance of the DNA replication system. MCM6 can also regulate downstream signaling such as MEK/ERK thus promoting carcinogenesis. Accordingly, MCM6 may represent a sensitive and specific biomarker to predict adverse progression and poor outcome. Furthermore, inhibition of MCM6 may be an effective cancer treatment. The present review summarizes the latest results on the inactivating and activating functions of MCM6, underlining its function in carcinogenesis. Further studies of the carcinogenic functions of MCM6 may provide novel insight into cancer biology and shed light on new approaches for cancer diagnosis and treatment.

Identification of MCM family as potential therapeutic and prognostic targets for hepatocellular carcinoma based on bioinformatics and experiments

AIMS

The minichromosome maintenance (MCM) complex is highly conserved, which has drawn increasing attention on physiology and pathology process. However, the role of MCM in hepatocellular carcinoma (HCC) remains largely unclear. We aimed to conduct systematic analysis of expression patterns, prognostic values and potential functions of nine MCM genes in HCC, thus identifying their role in HCC.

MAIN METHODS

In our study, we systemically analyzed the role of MCM in prognosis and HCC progression by several bioinformatics analysis tools. Immunohistochemical (IHC) assays were utilized to valid the protein expression of MCM in HCC and in vitro experiments were used to confirm the functions of MCMs in HCC proliferation.

KEY FINDINGS

Overexpression of MCM2-8 and MCM10 were found to be significantly associated with clinical parameters and poor prognosis of HCC patients. The function of MCM was mainly enriched in DNA replication. Moreover, MCM were also associated with several cancer pathway and drug sensitivity in HCC. Close correlations were observed between immune cell infiltration and MCM in HCC. Cell Counting Kit-8 (CCK-8) and clone formation assays suggested the role of MCM2-8 and MCM10 in HCC proliferation.

SIGNIFICANCE

These results have implied that deregulated MCM played an important role in HCC progression and might be considered as potential therapeutic and prognostic targets for HCC.

Increased expression of MCM4 is associated with poor prognosis in patients with hepatocellular carcinoma

Background

The minichromosome maintenance (MCM) protein complex is important for DNA replication. Moreover, the expression of specific MCM complex components has been associated with the survival of hepatocellular carcinoma (HCC) patients. However, the expression and functional roles of minichromosome maintenance complex component 4 (MCM4) in HCC development and progression have not yet been explored. We analyzed the expression and clinical significance of MCM4, including its association with liver cancer patient survival.

Methods

Oncomine, UALCAN, and HCCDB (a database of HCC expression atlas) were used to characterize the expression of MCM4 in tumor and normal tissues. The expression of MCM4 at the protein level was confirmed based on immunohistochemistry (IHC) data obtained from the Human Protein Atlas (HPA) database. The level of MCM4 was measured in tumor and adjacent normal tissues by RT-qPCR, western blot and IHC staining. The copy number alterations (CNAs) and mutations in MCM4 were analyzed by cBioPortal, whereas the co-expression genes of MCM4 in HCC were obtained from Oncomine, and used for gene ontology and pathway analysis via the NetworkAnalyst 3.0 tool, to explore the predictive signaling pathway in HCC.

Results

The levels of MCM4 messenger (m)RNA and protein were found to be significantly higher in liver cancer tissues than in normal liver tissues. Kaplan-Meier analysis showed that the upregulation of MCM4 was significantly negatively correlated with the survival of HCC patients.

Conclusions

Our data suggest that MCM4 may be used as a potential prognostic marker and therapeutic target for HCC.

A Mechanism of Action Study on Danggui Sini Decoction to Discover Its Therapeutic Effect on Gastric Cancer

Danggui Sini Decoction (DSD), a classic Chinese herb medicine (CHM) formula, has been used to treat various diseases in China for centuries. However, it remains challenging to reveal its mechanism of action through conventional pharmacological methods. Here, we first explored the mechanism of action of DSD with the assistance of network pharmacology and bioinformatic analysis tools, and found a potential therapeutic effect of DSD on cancer. Indeed, our in vivo experiment demonstrated that oral administration of DSD could significantly inhibit the growth of xenografted gastric cancer (GC) on mice. The subsequent enrichment analyses for 123 candidate core targets evacuated from the drug/disease-target protein-protein interaction network showed that DSD could affect the key biological processes involving the survival and growth of GC cells, such as apoptosis and cell cycle, and the disturbance of these biological processes is likely attributed to the simultaneous inhibition of multiple signaling pathways, including PI3K/Akt, MAPK, and p53 pathways. Notably, these in silico results were further validated by a series of cellular functional and molecular biological assays in vitro. Moreover, molecular docking analysis suggested an important role of MCM2 in delivering the pharmacological activity of DSD against GC. Together, these results indicate that our network pharmacology and bioinformatics-guided approach is feasible and useful in exploring not only the mechanism of action, but also the "new use" of the old CHM formula.

Identification of Potential Hub Genes Related to Diagnosis and Prognosis of Hepatitis B Virus-Related Hepatocellular Carcinoma via Integrated Bioinformatics Analysis

Hepatocellular carcinoma (HCC) is a common malignant cancer with poor survival outcomes, and hepatitis B virus (HBV) infection is most likely to contribute to HCC. But the molecular mechanism remains obscure. Our study intended to identify the candidate potential hub genes associated with the carcinogenesis of HBV-related HCC (HBV-HCC), which may be helpful in developing novel tumor biomarkers for potential targeted therapies. Four transcriptome datasets (GSE84402, GSE25097, GSE94660, and GSE121248) were used to screen the 309 overlapping differentially expressed genes (DEGs), including 100 upregulated genes and 209 downregulated genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment were used to explore the biological function of DEGs. A PPI network based on the STRING database was constructed and visualized by the Cytoscape software, consisting of 209 nodes and 1676 edges. Then, we recognized 17 hub genes by CytoHubba plugin, which were further validated on additional three datasets (GSE14520, TCGA-LIHC, and ICGC-LIRI-JP). The diagnostic effectiveness of hub genes was assessed with receiver operating characteristic (ROC) analysis, and all hub genes displayed good performance in discriminating TNM stage I patient samples and normal tissue ones. For prognostic analysis, two prognostic key genes (TOP2A and KIF11) out of the 17 hub genes were screened and used to develop a prognostic signature, which showed good potential for overall survival (OS) stratification of HBV-HCC patients. Gene Set Enrichment Analysis (GSEA) was performed in order to better understand the function of this prognostic gene signature. Finally, the miRNA-mRNA regulatory relationships of all hub genes in human liver were predicted using miRNet. In conclusion, the current study gives further insight on the pathogenesis and carcinogenesis of HBV-HCC, and the identified DEGs provide a promising direction for improving the diagnostic, prognostic, and therapeutic outcomes of HBV-HCC.

Identification of the DNA Replication Regulator MCM Complex Expression and Prognostic Significance in Hepatic Carcinoma

BACKGROUND

The microliposome maintenance (MCM) complex, MCM2-7, is revealed to be involved in multiple cellular processes and plays a key role in the development and progression of human cancers. However, the MCM complex remains poorly elaborated in hepatic carcinoma (HCC).

METHODS

In the study, we found the mRNA and protein level by bioinformatics. We also explored the prognostic value, genetic alteration, interaction network, and functional enrichment of MCM2-7. The MCM expression and correlation among these MCMs in HCC cell lines were identified by western blot.

RESULTS

MCM2-7 was significantly increased in HCC tissues compared to normal liver tissues. The high level of MCM2-7 had a positive correlation with poor prognosis. However, MCM2-7 alterations were not correlated with poor OS. MCMs were both increased in HCC cell lines compared to the normal hepatocyte cell line. Furthermore, the positive correlation was found among MCMs in HCC cell lines.

CONCLUSIONS

The MCM complex was increased in HCC tissues and cell lines and negatively correlated with prognosis, which might be important biomarkers for HCC.

DEAD-Box Helicase 4 (Ddx4)+ Stem Cells Sustain Tumor Progression in Non-Serous Ovarian Cancers

DEAD-Box Helicase 4 (Ddx4)⁺ ovarian stem cells are able to differentiate into several cell types under appropriate stimuli. Ddx4 expression has been correlated with poor prognosis of serous ovarian cancer (OC), while the potential role of Ddx4⁺ cells in non-serous epithelial OC (NS-EOC) is almost unexplored. The aim of this study was to demonstrate the presence of Ddx4⁺ cells in NS-EOC and investigate the effect of follicle-stimulating hormone (FSH) on this population. Increased Ddx4 expression was demonstrated in samples from patients with advanced NS-EOC, compared to those with early-stage disease. Under FSH stimulation, OC-derived Ddx4⁺ cells differentiated into mesenchymal-like (ML) cells, able to deregulate genes involved in cell migration, invasiveness, stemness and chemoresistance in A2780 OC cells. This effect was primarily induced by ML-cells deriving from advanced NS-EOC, suggesting that a tumor-conditioned germ cell niche inhabits its microenvironment and is able to modulate, in a paracrine manner, tumor cell behavior through transcriptome modulation.

Expression Profile and Prognostic Values of Mini-Chromosome Maintenance Families (MCMs) in Breast Cancer

Background

Mini-chromosome maintenance families (MCMs) were considered the key factors for DNA replication initiation. Emerging evidences indicate that MCM2-7 (MCMs) are highly expressed in tissues from various malignant tumors. However, little is known about the clinical values of MCMs in breast cancer.

Material/Methods

In our study, a comprehensive bioinformatics analysis was performed to investigate expression patterns, potential functions, and prognostic values of MCMs in breast cancer, through ONCOMINE, bc-GenExMiner v4.1, Kaplan-Meier Plotter, cBioPortal and GeneMANIA databases.

Results

We found that mRNA levels of MCMs were significantly elevated in breast cancer, especially in fast-growing and spreading tumor subtypes. These over-expressed MCMs predicted worse prognosis for breast cancer patients with shorter relapse-free survival (RFS) and overall survival. Among these six factors, high expression of MCM2/4/5/7 significantly reduced the RFS for patients with Luminal-A or B breast cancer and elevated MCM6/7 indicated shorter RFS for patients with basal-like or HER2-positive breast cancer. We also found that genomic alteration of MCMs was frequently found in breast cancer and the most common alteration was mRNA upregulation and amplification. Furthermore, MCMs were highly correlated with CDC45, CDC7, TIMELESS, ORC6, MCM10, ORC5, ORC4 and ORC3, mainly functioning to control the DNA replication initiation and genome stability.

Conclusions

These results suggest that MCMs are attractive prognostic biomarkers for breast cancer. Our study also provides useful clinical information about the potential of MCMs as therapeutic targets.

MCM family in gastrointestinal cancer and other malignancies: From functional characterization to clinical implication

Despite the recent advances in cancer research and treatment, gastrointestinal (GI) cancers remain the most common deadly disease worldwide. The aberrant DNA replication serves as a major source of genomic instability and enhances cell proliferation that contributes to tumor initiation and progression. Minichromosome maintenance family (MCMs) is a well-recognized group of proteins responsible for DNA synthesis. Recent studies suggested that dysregulated MCMs lead to tumor initiation, progression, and chemoresistance via modulating cell cycle and DNA replication stress. Their underlying mechanisms in various cancer types have been gradually identified. Furthermore, multiple studies have investigated the association between MCMs expression and clinicopathological features of cancer patients, implying that MCMs might serve as prominent prognostic biomarkers for GI cancers. This review summarizes the current knowledge on the oncogenic role of MCM proteins and highlights their clinical implications in various malignancies, especially in GI cancers. Targeting MCMs might shed light on the potential for identifying novel therapeutic strategies.

Minichromosome maintenance 6 complex component identified by bioinformatics analysis and experimental validation in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC), the main subtype of esophageal cancer (EC), is a common lethal type of cancer with a high mortality rate. The aim of the present study was to select key relevant genes and identify potential mechanisms involved in the development of ESCC based on bioinformatics analysis. Minichromosome maintenance 6 complex component (MCM6) has been identified to be upregulated in multiple malignancies; however, its contributions to ESCC remain unclear. For the purposes of the present study, four datasets were downloaded from the Gene Expression Omnibus (GSE63941, GSE26886, GSE17351 and GSE77861), and the intersection of the differentially expressed genes was obtained using a Venn diagram. The protein‑protein interaction was then constructed, and the modules were verified by Cytoscape, in which the key genes have a high connectivity degree with other genes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway were subsequently filtered out to analyze the development of ESCC. MCM6, an upregulated gene, was selected and connected with most of the other genes, for further research validation. The expression levels of MCM6 were then assessed using the Oncomine, GEPIA and UALCAN databases and validated in both ESCC tissues samples and cell lines by immunohistochemistry and RT‑qPCR. Cell counting kit‑8 (CCK‑8), flow cytometry, wound healing and Transwell assays were used to determine the proliferation, apoptosis, cell cycle, migration and invasion of ESCC cells. A total of 24 genes were identified by a series of bioinformatics analyses and the results revealed that the genes were associated with DNA replication and cell cycle. Experimental validation revealed that MCM6 expression was significantly elevated in both ESCC tissues and cell lines. The results were consistent with those of bioinformatics analysis. Furthermore, the knockdown of MCM6 inhibited cell proliferation, migration and invasion and promoted cell apoptosis, and made cells arrested in S stage. In summary, the findings of bioinformatics analysis provided a novel hypothesis for ESCC progression. In particular, the aberrantly elevated expression of MCM6 is a potential biomarker for ESCC diagnosis and treatment.

Overexpression of CSN6 promotes the epithelial-mesenchymal transition and predicts poor prognosis in hepatocellular carcinoma

BACKGROUND AND AIM

CSN6, as a critical subunit of the constitutive photomorphogenesis 9 (COP9) signalosome (CSN), has been previously reported to be increased in various cancers; however, its effect in hepatocellular carcinoma (HCC) remains unknown, which is the aim of present study, in terms of its explore the expression and role of CSN6 in HCC.

METHODS

QRT-PCR, Western blot and immunohistochemistry (IHC) were used to examine the expression of CSN6. Kaplan-Meier survival analysis and univariate and multivariate Cox analyses were used to investigate the clinical and prognostic significance of CSN6 expression in HCC patients. Furthermore, the biological function of CSN6 on HCC cell proliferation and migration was investigated through CCK-8, transwell migration and invasion assays. Besides, the associations between CSN6 and epithelial-mesenchymal transition (EMT) were determined.

RESULTS

CSN6 was increased in HCC tissues, and its overexpression was found to be associated with a poor prognoses for HCC patients. Overexpression of CSN6 promoted processes of HCC cell proliferation, migration, and invasion, while these processes were inhibited when CSN6 was silenced. Additionally, CSN6 was found to promote EMT by inhibiting E-cadherin, which were significantly mitigated via upregulation of Snail as a result of MEK/ERK pathway activation.

CONCLUSIONS

CSN6 up-regulation may play a contributory role in HCC metastasis and poor prognosis via activation of EMT, and may serve as an independent predictor for HCC prognosis.

The impact of MCM6 on hepatocellular carcinoma in a Southern Chinese Zhuang population

Minichromosome maintenance complex component 6 (MCM6) is involved in tumorigenesis of hepatocellular carcinoma (HCC). Because its effect on different populations remains unclear, this study investigated the impact of MCM6 on HCC in Southern Chinese Zhuang population. In addition to assessing the global mRNA levels of MCM6 based on The Cancer Genome Atlas database (TCGA) and The Gene Expression Omnibus database (GEO), associations between MCM6 mRNA levels and clinicopathological features were analyzed. High MCM6 levels were associated with high alpha-fetoprotein (AFP) (>20 ng/mL in serum) (P < 0.0001) and advanced clinical stage (III + IV) (P < 0.001). Higher MCM6 was associated with poorer outcomes (P < 0.01) in these databases. Furthermore, the mRNA and protein expression of MCM6 in the Guangxi Zhuang population was detected by quantitative polymerase chain reaction (qPCR), western blot, and immunohistochemistry (IHC). The results showed that MCM6 levels were up-regulated in the Zhuang population with HCC. Higher MCM6 protein levels were correlated with larger tumor size (>5 cm) (P = 0.038) and advanced clinical stage (III + IV) (p = 0.023). Bioinformatic enrichment analysis of MCM6 and its interacting proteins (CDT1,WEE1,TRIM28 and MKI67) suggested that in addition to being involved in the cell cycle process, these complexes could also be involved in protein binding, pre-replication complex assemble, and nucleus metabolism. Based on the protein-protein interaction (PPI) network with module screen, the interactions between MCM6 and its potential interacting proteins were further studied through protein docking with hot spot analysis. Additionally, the results of the algorithms combining the ROC of MCM6 and its interacting proteins showed that combination biomarker analysis has better HCC diagnosis ability than the single MCM6 test. The combination of MCM6 and TRIM28 was more suitable for the Guangxi Zhuang population. Overall, our study suggests that MCM6 plays an important role in the growth of HCC. MCM6 could be an optimal biomarker for diagnosing HCC and a potential molecular target for HCC therapy in the Zhuang population.

Identification of hub genes in hepatocellular carcinoma using integrated bioinformatic analysis

The molecular mechanisms underlying hepatocellular carcinoma (HCC) progression remain largely undefined. Here, we identified 176 commonly upregulated genes in HCC tissues based on three Gene Expression Omnibus datasets and The Cancer Genome Atlas (TCGA) cohort. We integrated survival and methylation analyses to further obtain 12 upregulated genes for validation. These genes were overexpressed in HCC tissues at the transcription and protein levels, and increased mRNA levels were related to higher tumor grades and cancer stages. The expression of all markers was negatively associated with overall and disease-free survival in HCC patients. Most of these hub genes can promote HCC proliferation and/or metastasis. These 12 hub genes were also overexpressed and had strong prognostic value in many other cancer types. Methylation and gene copy number analyses indicated that the upregulation of these hub genes was probably due to hypomethylation or increased gene copy numbers. Further, the methylation levels of three genes, KPNA2, MCM3, and LRRC1, were associated with HCC clinical features. Moreover, the levels of most hub genes were related to immune cell infiltration in HCC microenvironments. Finally, we identified three upregulated genes (KPNA2, TARBP1, and RNASEH2A) that could comprehensively and accurately provide diagnostic and prognostic value for HCC patients.

Gene Expression Alterations and Molecular Analysis of CHEK1 in Solid Tumors

Alterations in the Checkpoint kinase (CHEK1) gene, its regulation, and the possible clinical outcomes in human solid tumors have not been previously examined. Therefore, the present study was carried out to evaluate the expression of CHEK1 in solid tumors as well as the mechanism by which it can be regulated through non-coding RNAs. The expression of CHEK1 was investigated using Oncomine analysis. cBioPortal, Kaplan-Meier Plotter, and PrognoScan were performed to identify the prognostic roles of this gene in solid tumors. The copy number alteration, mutation, interactive analysis, and visualization of the altered networks were performed by cBioPortal. The molecular binding analysis was carried out by Schrodinger suite, PATCHDOCK, and discovery studio visualizer. The study demonstrated that the CHEK1 gene was differentially expressed in four different cancers, and that reduced CHEK1 mRNA expression is an unfavorable prognostic factor for patients with gastric and colorectal cancer. The molecular docking results showed that the CHEK1 gene can be regulated by microRNAs (miR-195-5p) due to the number of stable hydrogen atoms observed within the distance of 2.0 Å and the favorable amino acids (Ala221, Ile353, Ile365, Ile756, Val797, Val70, Val154, Ile159, Val347, Tyr804, Phe811, Tyr815, and Phe156) identified in the binding pocket of the argonaute protein. Due to the possibility of CHEK1's involvement in solid tumors, it may potentially be a target for therapeutic intervention in cancer. Further studies into the interaction between CHEK1 and other co-expressed genes may give further insight into other modes of regulation of this gene in cancer patients.

METTL3 Promotes the Progression of Gastric Cancer via Targeting the MYC Pathway

Methyltransferase-like 3 (METTL3), a major component of the N6-methyladenosine (m6A) methyltransferase complex, has been suggested to function as an oncogene in several cancers. However, its biological mechanism and the involved pathways in gastric cancer (GC) remain unknown. Here, we reported that frequent upregulation of METTL3 was responsible for the aberrant m6A levels in gastric carcinoma. On the other hand, a high level of METTL3 was significantly associated with several clinicopathological features and poor survival in patients with GC. The knockdown of METTL3 effectively inhibited cell proliferation and migration and invasion capacity. Moreover, overexpression of METTL3 considerably augmented its oncogenic function. Integrated RNA-seq and m6A-seq analysis first indicated that several component molecules (e.g., MCM5, MCM6, etc.) of MYC target genes were mediated by METTL3 via altered m6A modification. Our work uncovers the oncogenic roles of METTL3 in GC and suggests a critical mechanism of GC progression.

GTSE1, CDC20, PCNA, and MCM6 Synergistically Affect Regulations in Cell Cycle and Indicate Poor Prognosis in Liver Cancer

GTSE1 is well correlated with tumor progression; however, little is known regarding its role in liver cancer prognosis. By analyzing the hepatocellular carcinoma (HCC) datasets in GEO and TCGA databases, we showed that high expression of GTSE1 was correlated with advanced pathologic stage and poor prognosis of HCC patients. To investigate underlying molecular mechanism, we generated GTSE1 knockdown HCC cell line and explored the effects of GTSE1 deficiency in cell growth. Between GTSE1 knockdown and wild-type HCC cells, we identified 979 differentially expressed genes (520 downregulated and 459 upregulated genes) in the analysis of microarray-based gene expression profiling. Functional enrichment analysis of DEGs suggested that S phase was dysregulated without GTSE1 expression, which was further verified from flow cytometry analysis. Moreover, three other DEGs: CDC20, PCNA, and MCM6, were also found contributing to GTSE1-related cell cycle arrest and to be associated with poor overall survival of HCC patients. In conclusion, GTSE1, together with CDC20, PCNA, and MCM6, may synergistically promote adverse prognosis in HCC by activating cell cycle. Genes like GTSE1, CDC20, PCNA, and MCM6 may be promising prognostic molecular biomarkers in liver cancer.

Weighted gene coexpression network analysis identifies a new biomarker of CENPF for prediction disease prognosis and progression in nonmuscle invasive bladder cancer

BACKGROUND

The dreadful prognosis of nonmuscle invasive bladder cancer mainly results from the delay in recognition of individuals with a high risk of progression. Thus, the emphasis of this work lies in developing valuable biomarkers that is conducive to accurately predicting the progression of NMIBC.

METHODS

Microarray data from GSE32894 including 209 NMIBC samples were performed by weighted gene coexpression network analysis (WGCNA), which could find modules of highly correlated genes and relate modules to external sample traits. Besides, we constructed a protein-protein interaction to facilitate screening the hub gene. At last, we used RNA-seq and microarray data and clinical information from ArrayExpress (E-MTAB-4321) and GSE13507 to select and validate the candidate gene.

RESULTS

In current paper, blue module of 13 gene coexpression clusters we identified was selected as the key modules. Seven genes namely: CDCA8, CENPF, MCM6, MELK, PRC1, STIL, and TPX2 have been identified as candidate genes. Notably, among them, only elevated CENPF in NIMBC tissue was closely associated with low progression-free survival (PFS) and overall survival (OS) rate in three datasets and had a large area under receiver operating characteristic (ROC) curve. Finally, CENPF was identified as an effective biomarker in NMIBC.

CONCLUSION

Therefore, our findings submit a new progressive and prognostic molecular marker and therapeutic target for NMIBC. Moreover, these genes that deserve to be further researched may improve the comprehension about the occurrence and development of superficial bladder cancer.

CDK5RAP3 Inhibits the Translocation of MCM6 to Influence the Prognosis in Gastric Cancer

Cyclin-dependent kinase 5 regulatory subunit-associated protein 3 (CDK5RAP3) was identified as a tumor suppressor in gastric cancer, while, minichromosome maintenance complex component 6 (MCM6), which is closely related to the initiation of DNA replication, was reported to be upregulated in multiple malignancies. However, the interaction between these two proteins has not been investigated in gastric cancer. Here, we evaluate the connection between CDK5RAP3 and MCM6 using mass spectrometry and immunoprecipitation. In cells, cell growth and invasiveness indicate that CDK5RAP3 acts as a tumor suppressor by preventing the effects of MCM6. The potential mechanism was revealed using immunofluorescence and nuclear protein extraction. In patients, immunohistochemistry and immunofluorescence show that the protein levels of CDK5RAP3 were markedly decreased in most gastric tumor tissues compared with adjacent nontumor tissues, and the expression levels of MCM6 in the nucleus showed the opposite trend. Prognostic analysis showed that the combined expression of CDK5RAP3 and MCM6 was an independent prognostic factor correlating with the overall survival of gastric cancer patients. Cox regression analysis indicated that the expression of CDK5RAP3 and MCM6 corresponded to T, N, and M stages. Our results demonstrate that CDK5RAP3 can interact with MCM6 and prevent MCM6 from translocating into the nucleus, which may be a potential mechanism through which CDK5RAP3 negatively regulates the proliferation of gastric cancer.

Recent advances in molecular biomarkers for patients with hepatocellular carcinoma

Introduction: Hepatocellular carcinoma (HCC) is a leading cause of cancer death worldwide and recurrence rate after curative resection remains high. To improve HCC prognosis, novel sensitive biomarkers and targeted molecular therapies are needed. Accumulation of multiple genetic aberrations caused by pathologically derived liver damage results in HCC carcinogenesis. Elucidating the genes associated with tumorigenesis and progression of HCC may lead to the development of early detection and prognosis markers and to the identification of therapeutic targets. Areas covered: We review recently reported (January 2017-March 2019) HCC-associated molecules, including protein-coding genes, microRNAs, long non-coding RNAs, and methylated gene promoters. Expert opinion: The molecules reviewed have the potential to be clinical biomarkers and therapeutic targets for HCC. The accumulation and understanding of genetic and epigenetic data are essential to improve the management of HCC patients.

Minichromosome maintenance 3 promotes hepatocellular carcinoma radioresistance by activating the NF-κB pathway

Background

Hepatocellular carcinoma (HCC) is the most common tumors in the worldwide, it develops resistance to radiotherapy during treatment, understanding the regulatory mechanisms of radioresistance generation is the urgent need for HCC therapy.

Methods

qRT-PCR, western blot and immunohistochemistry were used to examine MCM3 expression. MTT assay, colony formation assay, terminal deoxynucleotidyl transferase nick end labeling assay and In vivo xenograft assay were used to determine the effect of MCM3 on radioresistance. Gene set enrichment analysis, luciferase reporter assay, western blot and qRT-PCR were used to examine the effect of MCM3 on NF-κB pathway.

Results

We found DNA replication initiation protein Minichromosome Maintenance 3 (MCM3) was upregulated in HCC tissues and cells, patients with high MCM3 expression had poor outcome, it was an independent prognostic factor for HCC. Cells with high MCM3 expression or MCM3 overexpression increased the radioresistance determined by MTT assay, colony formation assay, TUNEL assay and orthotopic transplantation mouse model, while cells with low MCM3 expression or MCM3 knockdown reduced the radioresistance. Mechanism analysis showed MCM3 activated NF-κB pathway, characterized by increasing the nuclear translocation of p65, the expression of the downstream genes NF-κB pathway and the phosphorylation of IKK-β and IκBα. Inhibition of NF-κB in MCM3 overexpressing cells using small molecular inhibitor reduced the radioresistance, suggesting MCM3 increased radioresistance through activating NF-κB pathway. Moreover, we found MCM3 expression positively correlated with NF-κB pathway in clinic.

Conclusions

Our findings revealed that MCM3 promoted radioresistance through activating NF-κB pathway, strengthening the role of MCM subunits in the tumor progression and providing a new target for HCC therapy.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1241-9) contains supplementary material, which is available to authorized users.

Overexpression of KCNJ4 correlates with cancer progression and unfavorable prognosis in lung adenocarcinoma

KCNJ4 (potassium voltage-gated channel subfamily J member 4) belongs to the inward rectifier potassium channel family, which is inhibited by novel anticancer agents. However, the biologic significance of KCNJ4 in lung adenocarcinoma (LADC) is largely unknown. Therefore, in this study, we evaluated the expression, clinical correlation, and prognostic value of KCNJ4 in LADC and normal lung tissues according to data from The Cancer Genome Atlas datasets. A small interfering RNA (siRNA)-mediated technology was used to inhibit the expression level of KCNJ4. Cell counting kit-8 and plate colony formation assays were used to measure cell proliferation. Wound-healing and transwell assays were applied to detect cell mobility and metastasis. Quantitative real-time polymerase chain reaction and western blot analysis were used to examine messenger RNA and protein expressions, respectively. It was found that KCNJ4 was significantly upregulated in LADC tissues and cells. The high level of KCNJ4 predicted shorter overall survival and was identified as an independent prognostic factor in patients with LADC. siRNA-mediated KCNJ4 silencing impeded LADC cell proliferation, migration, and invasion. Knockdown of KCNJ4 suppressed the expression of phosphorylated mitogen-activated protein kinase/extracellular signal regulated kinase (p-MEK) and phosphorylated extracellular signal-regulated kinase (p-ERK). Collectively, these results shed some light on the contribution of KCNJ4 functioning as a significant player in LADC, implying that KCNJ4 might be a valuable prognostic biomarker and a potential therapeutic target for LADC treatment.