The Expression of MCM7 is a Useful Biomarker in the Early Diagnostic of Gastric Cancer

Identifying Genetic Signatures Associated with Oncogene-Induced Replication Stress in Osteosarcoma and Screening for Potential Targeted Drugs

Osteosarcoma is the most common type of primary malignant bone tumor. Due to the lack of selectivity and sensitivity of chemotherapy drugs to tumor cells, coupled with the use of large doses, chemotherapy drugs often have systemic toxicity. The use of modern sequencing technology to screen tumor markers in a large number of tumor samples is a common method for screening highly specific and selective anti-tumor drugs. This study aims to identify potential biomarkers using the latest reported gene expression signatures of oncogene-induced replication stress (ORS) in aggressive cancers, and potential anti-osteosarcoma drugs were screened in different drug databases. In this study, we obtained 89 osteosarcoma-related samples in the TARGET database, all of which included survival information. According to the median expression of each of six reported ORS gene markers (NAT10/DDX27/ZNF48/C8ORF33/MOCS3/MPP6), we divided 89 osteosarcoma gene expression datasets into a high expression group and a low expression group and then performed a differentially expressed gene (DEG) analysis. The coexisting genes of 6 groups of DEGs were used as replication stress-related genes (RSGs) of osteosarcoma. Then, key RSGs were screened using LASSO regression, a Cox risk proportional regression prognostic model and a tenfold cross-validation test. GSE21257 datasets collected from the Gene Expression Omnibus (GEO) database were used to verify the prognostic model. The final key RSGs selected were used in the L1000PWD and DGIdb databases to mine potential drugs. After further validation by the prognostic model, we identified seven genes associated with ORS in osteosarcoma as key RSGs, including transcription factor 7 like 2 (TCF7L2), solute carrier family 27 member 4 (SLC27A4), proprotein convertase subtilisin/kexin type 5 (PCSK5), nucleolar protein 6 (NOL6), coiled-coil-coil-coil-coil-helix domain containing 4 (CHCHD4), eukaryotic translation initiation factor 3 subunit B (EIF3B), and synthesis of cytochrome C oxidase 1 (SCO1). Then, we screened the seven key RSGs in two drug databases and found six potential anti-osteosarcoma drugs (D GIdb database: repaglinide, tacrolimus, sirolimus, cyclosporine, and hydrochlorothiazide; L1000PWD database: the small molecule VU-0365117-1). Seven RSGs (TCF7L2, SLC27A4, PCSK5, NOL6, CHCHD4, EIF3B, and SCO1) may be associated with the ORS gene signatures in osteosarcoma. Repaglinide, tacrolimus, sirolimus, cyclosporine, hydrochlorothiazide and the small molecule VU-0365117-1 are potential therapeutic drugs for osteosarcoma.

Construction of immune-related molecular diagnostic and predictive models of hepatocellular carcinoma based on machine learning

Background

To exploit hepatocellular carcinoma (HCC) diagnostic substances, we identify potential predictive markers based on machine learning and to explore the significance of immune cell infiltration in this pathology.

Method

Three HCC gene expression datasets were used for weighted gene co-expression network analysis (WGCNA) and differential expression analysis. Least Absolute Shrinkage and Selection Operator (LASSO) and Random Forest were applied to identify candidate biomarkers. The diagnostic value of HCC diagnostic gene biomarkers was further assessed by the area under the ROC curve observed in the validation dataset. CIBERSORT was used to analyze 22 immune cell fractions from HCC patients and to analyze their correlation with diagnostic markers. In addition, the prognostic value of the markers and the sensitivity of the drugs were analyzed.

Result

WGCNA and differential expression analysis were used to screen 396 distinct gene signatures in HCC tissues. They were mostly engaged in cytoplasmic fusion and the cell division cycle, according to gene enrichment analyses. Five genes were shown to have a high diagnostic value for use as diagnostic biomarkers for HCC, including EFHD1 (AUC = 0.77), KIF4A (AUC = 0.97), UBE2C (AUC = 0.96), SMYD3 (AUC = 0.91), and MCM7 (AUC = 0.93). T cells, NK cells, macrophages, and dendritic cells were found to be related to diagnostic markers in HCC tissues by immune cell infiltration analysis, indicating that these cells are intimately linked to the onset and spread of HCC. Concurrently, these five genes and their constructed models have considerable prognostic value.

Conclusion

These five genes (EFHD1, KIF4A, UBE2C, SMYD3, and MCM7) may serve as new candidate molecular markers for HCC, providing new insights for future diagnosis, prognosis, and molecular therapy of HCC.

Early diagnostic and prognostic biomarkers for gastric cancer: systems-level molecular basis of subsequent alterations in gastric mucosa from chronic atrophic gastritis to gastric cancer

PURPOSE

It is important to comprehend how the molecular mechanisms shift when gastric cancer in its early stages (GC). We employed integrative bioinformatics approaches to locate various biological signalling pathways and molecular fingerprints to comprehend the pathophysiology of the GC. To facilitate the discovery of their possible biomarkers, a rapid diagnostic may be made, which leads to an improved diagnosis and improves the patient's prognosis.

METHODS

Through protein-protein interaction networks, functional differentially expressed genes (DEGs), and pathway enrichment studies, we examined the gene expression profiles of individuals with chronic atrophic gastritis and GC.

RESULTS

A total of 17 DEGs comprising 8 upregulated and 9 down-regulated genes were identified from the microarray dataset from biopsies with chronic atrophic gastritis and GC. These DEGs were primarily enriched for CDK regulation of DNA replication and mitotic M-M/G1 phase pathways, according to KEGG analysis (p > 0.05). We discovered two hub genes, MCM7 and CDC6, in the protein-protein interaction network we obtained for the 17 DEGs (expanded with increased maximum interaction with 110 nodes and 2103 edges). MCM7 was discovered to be up-regulated in GC tissues following confirmation using the GEPIA and Human Protein Atlas databases.

CONCLUSION

The elevated expression of MCM7 in both chronic atrophic gastritis and GC, as shown by our comprehensive investigation, suggests that this protein may serve as a promising biomarker for the early detection of GC.

DNA replication: Mechanisms and therapeutic interventions for diseases

Accurate and integral cellular DNA replication is modulated by multiple replication-associated proteins, which is fundamental to preserve genome stability. Furthermore, replication proteins cooperate with multiple DNA damage factors to deal with replication stress through mechanisms beyond their role in replication. Cancer cells with chronic replication stress exhibit aberrant DNA replication and DNA damage response, providing an exploitable therapeutic target in tumors. Numerous evidence has indicated that posttranslational modifications (PTMs) of replication proteins present distinct functions in DNA replication and respond to replication stress. In addition, abundant replication proteins are involved in tumorigenesis and development, which act as diagnostic and prognostic biomarkers in some tumors, implying these proteins act as therapeutic targets in clinical. Replication-target cancer therapy emerges as the times require. In this context, we outline the current investigation of the DNA replication mechanism, and simultaneously enumerate the aberrant expression of replication proteins as hallmark for various diseases, revealing their therapeutic potential for target therapy. Meanwhile, we also discuss current observations that the novel PTM of replication proteins in response to replication stress, which seems to be a promising strategy to eliminate diseases.

Elevation of fatty acid desaturase 2 in esophageal adenocarcinoma increases polyunsaturated lipids and may exacerbate bile acid-induced DNA damage

Background

The risk of esophageal adenocarcinoma (EAC) is associated with gastro‐esophageal reflux disease (GERD) and obesity. Lipid metabolism‐targeted therapies decrease the risk of progressing from Barrett's esophagus (BE) to EAC, but the precise lipid metabolic changes and their roles in genotoxicity during EAC development are yet to be established.

Methods

Esophageal biopsies from the normal epithelium (NE), BE, and EAC, were analyzed using concurrent lipidomics and proteomics (n = 30) followed by orthogonal validation on independent samples using RNAseq transcriptomics (n = 22) and immunohistochemistry (IHC, n = 80). The EAC cell line FLO‐1 was treated with FADS2 selective inhibitor SC26196, and/or bile acid cocktail, followed by immunofluorescence staining for γH2AX.

Results

Metabolism‐focused Reactome analysis of the proteomics data revealed enrichment of fatty acid metabolism, ketone body metabolism, and biosynthesis of specialized pro‐resolving mediators in EAC pathogenesis. Lipidomics revealed progressive alterations (NE‐BE‐EAC) in glycerophospholipid synthesis with decreasing triglycerides and increasing phosphatidylcholine and phosphatidylethanolamine, and sphingolipid synthesis with decreasing dihydroceramide and increasing ceramides. Furthermore, a progressive increase in lipids with C20 fatty acids and polyunsaturated lipids with ≥4 double bonds were also observed. Integration with transcriptome data identified candidate enzymes for IHC validation: Δ4‐Desaturase, Sphingolipid 1 (DEGS1) which desaturates dihydroceramide to ceramide, and Δ5 and Δ6‐Desaturases (fatty acid desaturases, FADS1 and FADS2), responsible for polyunsaturation. All three enzymes showed significant increases from BE through dysplasia to EAC, but transcript levels of DEGS1 were decreased suggesting post‐translational regulation. Finally, the FADS2 selective inhibitor SC26196 significantly reduced polyunsaturated lipids with three and four double bonds and reduced bile acid‐induced DNA double‐strand breaks in FLO‐1 cells in vitro.

Conclusions

Integrated multiomics revealed sphingolipid and phospholipid metabolism rewiring during EAC development. FADS2 inhibition and reduction of the high polyunsaturated lipids effectively protected EAC cells from bile acid‐induced DNA damage in vitro, potentially through reduced lipid peroxidation.

NOL6 Regulates the Proliferation and Apoptosis of Gastric Cancer Cells via Regulating TP53I3, CDK4 and MCM7 Expression

Background

Gastric cancer (GC) is a prevalent cancer with high mortality and strong invasiveness, and the entire regulatory networks of GC is still unclear.

Objective

The aim of this study was to explore the specific mechanism of the effect of nucleolar protein 6 (NOL6) on the proliferation and apoptosis of GC cells.

Methods

The human gastric adenocarcinoma cell line HGC-27 and AGS were cultured. qRT-PCR was used to verify the expression level of NOL6 in GC cells; MTT and EdU were used to test cell proliferation; TUNEL staining and Flow cytometry were used to detect cell apoptosis; The downstream genes and pathways following NOL6 knockdown were explored through the microarray assay and ingenuity pathway analysis, and the downstream genes were finally verified by qRT-PCR and Western blotting. The xenograft mice were used to investigate the effect of NOL6 on GC in vivo.

Results

TCGA data analysis showed that NOL6 expression level was higher in GC cells than adjacent normal cells. Over-expression of NOL6 increased proliferation and colony formation, and inhibited the apoptotic rate in AGS and HGC-27 cells, while NOL6 knockdown induced the opposite effects. Through microarray assay and IPA analysis, NOL6-related downstream genes and critical signaling pathways were found. And we verified the relationship between downstream genes and GC. Additionally, NOL6 knockdown could decrease the weight and volume of tumor in the mice.

Conclusion

NOL6 knockdown could inhibit cell proliferation and induce cell apoptosis of GC, suggesting that NOL6 may serve as a potential therapeutic target for treating GC.

MCM2-7 in Clear Cell Renal Cell Carcinoma: MCM7 Promotes Tumor Cell Proliferation

Background

Clear cell renal cell carcinoma (ccRCC) accounts for 60-70% of renal cell carcinoma (RCC) cases. Finding more therapeutic targets for advanced ccRCC is an urgent mission. The minichromosome maintenance proteins 2-7 (MCM2-7) protein forms a stable heterohexamer and plays an important role in DNA replication in eukaryotic cells. In the study, we provide a comprehensive study of MCM2-7 genes expression and their potential roles in ccRCC.

Methods

The expression and prognosis of the MCM2-7 genes in ccRCC were analyzed using data from TCGA, GEO and ArrayExpress. MCM2-7 related genes were identified by weighted co-expression network analysis (WGCNA) and Metascape. CancerSEA and GSEA were used to analyze the function of MCM2–7 genes in ccRCC. The gene effect scores (CERES) of MCM2-7, which reflects carcinogenic or tumor suppressor, were obtained from DepMap. We used clinical and expression data of MCM2-7 from the TCGA dataset and the LASSO Cox regression analysis to develop a risk score to predict survival of patients with ccRCC. The correlations between risk score and other clinical indicators such as gender, age and stage were also analyzed. Further validation of this risk score was engaged in another cohort, E-MTAB-1980 from the ArrayExpress dataset.

Results

The mRNA and protein expression of MCM2-7 were increased in ccRCC compared with normal tissues. High MCM2, MCM4, MCM6 and MCM7 expression were associated with a poor prognosis of ccRCC patients. Functional enrichment analysis revealed that MCM2-7 might influence the progress of ccRCC by regulating the cell cycle. Knockdown of MCM7 can inhibit the proliferation of ccRCC cells. A two-gene risk score including MCM4 and MCM6 can predict overall survival (OS) of ccRCC patients. The risk score was successfully verified by further using Arrayexpress cohort.

Conclusion

We analyze MCM2-7 mRNA and protein levels in ccRCC. MCM7 is determined to promote tumor proliferation. Meanwhile, our study has determined a risk score model composed of MCM2-7 can predict the prognosis of ccRCC patients, which may help future treatment strategies.

MCM7 affects the cisplatin resistance of liver cancer cells and the development of liver cancer by regulating the PI3K/Akt signaling pathway

OBJECTIVE

Aberrant DNA replication is regarded as a component of cancer development. Minichromosome maintenance protein 7 (MCM7), which is critical for the initiation of DNA replication, is overexpressed in multiple malignancies. The effect of MCM7 on cell proliferation, apoptosis, and drug resistance of liver cancer and its mechanism were investigated in this study.

METHODS

MCM7 expression in normal liver cells, liver cancer cell lines, and tissues, as well as adjacent tissues, was determined by qRT-PCR. CCK-8 and flow cytometry was performed to detect cell viability, apoptosis, and cell cycle, respectively. The related mRNA and protein expressions were detected by qRT-PCR and western blot.

RESULTS

High expression of MCM7 was found in liver cancer tissues and cells, which results in notably lower survival time of patients. Cisplatin (DDP) could inhibit cell proliferation and affect MCM7 expression. Silencing of MCM7 inhibited cell viability, promoted cell apoptosis, arrested cell cycle at G1 phase, and enhanced the effect of DDP on cancer cells, while overexpression of MCM7 did the opposite. Moreover, silencing of MCM7 inhibited cyclinD1 and Ki-67 expressions. The overexpression of MCM7 increased phosphorylation levels of PI3K and AKT, activated the PI3K/AKT pathway, and weakened the inhibitory effect of DDP on the PI3K/AKT pathway.

CONCLUSION

Silencing of MCM7 may inhibit cell proliferation and promote apoptosis by regulating the PI3K/AKT pathway to affect the cell cycle, thus affecting the development of liver cancer, and improving the sensitivity of liver cancer cells to DDP.

Computational Screening of Natural Compounds for Identification of Potential Anti-Cancer Agents Targeting MCM7 Protein

Minichromosome maintenance complex component 7 (MCM7) is involved in replicative licensing and the synthesis of DNA, and its overexpression is a fascinating biomarker for various cancer types. There is currently no effective agent that can prevent the development of cancer caused by the MCM7 protein. However, on the molecular level, inhibiting MCM7 lowers cancer-related cellular growth. With this purpose, this study screened 452 biogenic compounds extracted from the UEFS Natural Products dataset against MCM protein by using the in silico art of technique. The hit compounds UEFS99, UEFS137, and UEFS428 showed good binding with the MCM7 protein with binding energy values of −9.95, −8.92, and −8.71 kcal/mol, which was comparatively higher than that of the control compound ciprofloxacin (−6.50). The hit (UEFS99) with the minimum binding energy was picked for molecular dynamics (MD) simulation investigation, and it demonstrated stability at 30 ns. Computational prediction of physicochemical property evaluation revealed that these hits are non-toxic and have good drug-likeness features. It is suggested that hit compounds UEFS99, UEFS137, and UEFS428 pave the way for further bench work validation in novel inhibitor development against MCM7 to fight the cancers.

Molecular Mechanisms of Antiproliferative and Apoptosis Activity by 1,5-Bis(4-Hydroxy-3-Methoxyphenyl)1,4-Pentadiene-3-one (MS13) on Human Non-Small Cell Lung Cancer Cells

Diarylpentanoid (DAP), an analog that was structurally modified from a naturally occurring curcumin, has shown to enhance anticancer efficacy compared to its parent compound in various cancers. This study aims to determine the cytotoxicity, antiproliferative, and apoptotic activity of diarylpentanoid MS13 on two subtypes of non-small cell lung cancer (NSCLC) cells: squamous cell carcinoma (NCI-H520) and adenocarcinoma (NCI-H23). Gene expression analysis was performed using Nanostring PanCancer Pathways Panel to determine significant signaling pathways and targeted genes in these treated cells. Cytotoxicity screening revealed that MS13 exhibited greater inhibitory effect in NCI-H520 and NCI-H23 cells compared to curcumin. MS13 induced anti-proliferative activity in both cells in a dose- and time-dependent manner. Morphological analysis revealed that a significant number of MS13-treated cells exhibited apoptosis. A significant increase in caspase-3 activity and decrease in Bcl-2 protein concentration was noted in both MS13-treated cells in a time- and dose-dependent manner. A total of 77 and 47 differential expressed genes (DEGs) were regulated in MS13 treated-NCI-H520 and NCI-H23 cells, respectively. Among the DEGs, 22 were mutually expressed in both NCI-H520 and NCI-H23 cells in response to MS13 treatment. The top DEGs modulated by MS13 in NCI-H520—DUSP4, CDKN1A, GADD45G, NGFR, and EPHA2—and NCI-H23 cells—HGF, MET, COL5A2, MCM7, and GNG4—were highly associated with PI3K, cell cycle-apoptosis, and MAPK signaling pathways. In conclusion, MS13 may induce antiproliferation and apoptosis activity in squamous cell carcinoma and adenocarcinoma of NSCLC cells by modulating DEGs associated with PI3K-AKT, cell cycle-apoptosis, and MAPK pathways. Therefore, our present findings could provide an insight into the anticancer activity of MS13 and merits further investigation as a potential anticancer agent for NSCLC cancer therapy.

miR-107 regulates the effect of MCM7 on the proliferation and apoptosis of colorectal cancer via the PAK2 pathway

Microchromosome maintenance protein 7 (MCM7), a DNA replication permitting factor, plays an essential role in initiating DNA replication. MCM7 is reported to be involved in tumor formation and progression, whereas the expression profile and molecular function of MCM7 in colorectal cancer (CRC) remain unknown. In this study, we aimed to evaluate the clinical significance and biological function of MCM7 in CRC and investigated whether MCM7 can be used for a differential diagnosis in CRC and whether it may serve as a more sensitive proliferation marker for CRC evaluation. Moreover, immunohistochemical analysis of MCM7 was performed in a total of 89 specimens, and high MCM7 expression levels were associated with worse overall survival (OS) in CRC patients. Furthermore, the cell functional test suggested that lentivirus-mediated silencing of MCM7 with shRNA in CRC cells significantly inhibited cellular proliferation and promoted apoptosis in vitro and inhibited tumor growth in vivo. Additionally, mechanistic studies further demonstrated that P21-activated protein kinase 2 (PAK2) was regulated by MCM7 via microarray analysis and cell functional recovery tests, and miR-107 played a role in regulating expression MCM7 via miRNA microarray analysis and 3'UTR reporter assays. Taken together, our results suggest that the miR-107/MCM7/PAK2 pathway may participate in cancer progression and that MCM7 may serve as a prognostic biomarker in CRC.

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.

Microarray Data Mining and Preliminary Bioinformatics Analysis of Hepatitis D Virus-Associated Hepatocellular Carcinoma

Several studies have demonstrated that chronic hepatitis delta virus (HDV) infection is associated with a worsening of hepatitis B virus (HBV) infection and increased risk of hepatocellular carcinoma (HCC). However, there is limited data on the role of HDV in the oncogenesis of HCC. This study is aimed at assessing the potential mechanisms of HDV-associated hepatocarcinogenesis, especially to screen and identify key genes and pathways possibly involved in the pathogenesis of HCC. We selected three microarray datasets: GSE55092 contains 39 cancer specimens and 81 paracancer specimens from 11 HBV-associated HCC patients, GSE98383 contains 11 cancer specimens and 24 paracancer specimens from 5 HDV-associated HCC patients, and 371 HCC patients with the RNA-sequencing data combined with their clinical data from the Cancer Genome Atlas (TCGA). Afterwards, 948 differentially expressed genes (DEGs) closely related to HDV-associated HCC were obtained using the R package and filtering with a Venn diagram. We then performed gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to determine the biological processes (BP), cellular component (CC), molecular function (MF), and KEGG signaling pathways most enriched for DEGs. Additionally, we performed Weighted Gene Coexpression Network Analysis (WGCNA) and protein-to-protein interaction (PPI) network construction with 948 DEGs, from which one module was identified by WGCNA and three modules were identified by the PPI network. Subsequently, we validated the expression of 52 hub genes from the PPI network with an independent set of HCC dataset stored in the Gene Expression Profiling Interactive Analysis (GEPIA) database. Finally, seven potential key genes were identified by intersecting with key modules from WGCNA, including 3 reported genes, namely, CDCA5, CENPH, and MCM7, and 4 novel genes, namely, CDC6, CDC45, CDCA8, and MCM4, which are associated with nucleoplasm, cell cycle, DNA replication, and mitotic cell cycle. The CDCA8 and stage of HCC were the independent factors associated with overall survival of HDV-associated HCC. All the related findings of these genes can help gain a better understanding of the role of HDV in the underlying mechanism of HCC carcinogenesis.

Catalpol inhibits the proliferation, migration and metastasis of HCC cells by regulating miR‑140‑5p expression

Hepatocellular carcinoma (HCC) is a frequent malignant tumor. Catalpol is a Chinese medicine extract with a number of pharmacologically active properties. The present study aimed to investigate the effects and mechanisms of catalpol in HCC. HCC cells were treated with catalpol in the presence or absence of microRNA (miR)-140-5p inhibitor, and assays to determine cell viability, proliferation, invasion and migration were performed. Reverse transcription-quantitative PCR and western blotting were performed to determine the mRNA and protein expression levels of miR-140-5p, vimentin, N-Cadherin and E-Cadherin. Moreover, cells were treated with catalpol in the absence or presence of transforming growth factor (TGF)-β1, and the cell morphology was observed under a microscope. The results demonstrated that catalpol inhibited cell proliferation, invasion and migration, and decreased the expression levels of vimentin and N-cadherin, but increased the expression levels of E-cadherin and miR-140-5p. Catalpol inhibited morphological changes in epithelial-mesenchymal transformation (EMT) of cells induced by TGF-β1. Following inhibition of miR-140-5p expression, the proliferation, invasion and migration of HCC cells were promoted, E-cadherin expression was decreased, and the levels of vimentin and N-cadherin were increased. The miR-140-5p inhibitor effectively reversed the inhibitory effect of catalpol on cell proliferation, invasion and migration. Thus, the results suggested that the antitumor potential of catalpol in HCC may be exerted by regulating the expression of miR-140-5p to inhibit proliferation, invasion, migration and EMT of HCC cells.

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.

Identification of Hub Genes as Biomarkers Correlated with the Proliferation and Prognosis in Lung Cancer: A Weighted Gene Co-Expression Network Analysis

Lung cancer is one of the most malignant tumors in the world. Early diagnosis and treatment of lung cancer are vitally important to reduce the mortality of lung cancer patients. In the present study, we attempt to identify the candidate biomarkers for lung cancer by weighted gene co-expression network analysis (WGCNA). Gene expression profile of GSE30219 was downloaded from the gene expression omnibus (GEO) database. The differentially expressed genes (DEGs) were analyzed by the limma package, and the co-expression modules of genes were built by WGCNA. UALCAN was used to analyze the relative expression of normal group and tumor subgroups based on tumor individual cancer stages. Survival analysis for the hub genes was performed by Kaplan–Meier plotter analysis with the TCGA database. A total of 2176 genes (745 upregulated and 1431 downregulated genes) were obtained from the GSE30219 database. Seven gene co-expression modules were conducted by WGCNA and the blue module might be inferred as the most crucial module in the pathogenesis of lung cancer. In the pathway enrichment analysis of KEGG, the candidate genes were enriched in the “DNA replication,” “Cell cycle,” and “P53 signaling pathway” pathways. Among these, the cell cycle pathway was the most significant pathway in the blue module with four hub genes CCNB1, CCNE2, MCM7, and PCNA which were selected in our study. Kaplan–Meier plotter analysis indicated that the high expressions of four hub genes were correlated with a worse overall survival (OS) and advanced tumors. qRT-PCR showed that mRNA expression levels of MCM7 (p = 0.038) and CCNE2 (0.003) were significantly higher in patients with the TNM stage. In summary, the high expression of the MCM7 and CCNE2 were significantly related with advanced tumors and worse OS in lung cancer. Thus, the MCM7 and CCNE2 genes can be good indicators for cellular proliferation and prognosis in lung cancer.

MCM7 silencing promotes cutaneous melanoma cell autophagy and apoptosis by inactivating the AKT1/mTOR signaling pathway

Cutaneous melanoma (CM) has become a major public health concern. Studies illustrate that minichromosome maintenance protein 7 (MCM7) participate in various diseases including skin disease. Our study aimed to study the effects of MCM7 silencing on CM cell autophagy and apoptosis by modulating the AKT threonine kinase 1 (AKT1)/mechanistic target of rapamycin kinase (mTOR) signaling pathway. Initially, microarray analysis was used to screen the CM-related gene expression data as well as differentially expressed genes. Subsequently, MCM7 expression vector and lentivirus RNA used for MCM7 silencing (LV-shRNA-MCM7) were constructed, and these vectors, dimethyl sulfoxide (DMSO) and AKT activator SC79 were then introduced into CM cell line SK-MEL-2 to validate the role of MCM7 in cell autophagy, viability, apoptosis, cell cycle, migration, and invasion. To further investigate the regulatory mechanisms of MCM7 in CM progress, the expression of MCM7, AKT1, mTOR, cyclin D1, as well as autophagy and apoptosis relative factors, such as LC3B, SOD2, DJ-1, p62, Bcl-2, Bax, and caspase-3 in melanoma cells was determined. MCM7 might mediate the AKT1/mTOR signaling pathway to influence the progress of melanoma. MCM7 silencing contributed to the increased expression of Bax, capase-3, and autophagy-related genes (LC3B, SOD2, and DJ-1), but decreased the expression of Bcl-2, which suggested that MCM7 silencing promoted autophagy and cell apoptosis. At the same time, MCM7 silencing also attenuated cell viability, invasion, and migration, and reduced the cyclin D1 expression and protein levels of p-AKT1 and p-mTOR. Taken together, MCM7 silencing inhibited CM via inactivation of the AKT1/mTOR signaling pathway.

Comprehensive Analysis of the Expression and Prognosis for MCMs in Human Gastric Cancer

PURPOSES

Minichromosome maintenance (MCM) proteins play an important role in replication and cell cycle progression. Even so, their expression and prognostic roles in cancer remain controversial.

METHODS

To address this issue, the study investigated the roles of MCMs in the prognosis of GC by using ONCOMINE, GEPIA2, UALCAN, Cancer Cell Line Encyclopedia (CCLE), the Human Protein Atlas, Kaplan-Meier Plotter, cBioPortal, GeneMANIA, and DAVID databases.

RESULTS

Over expressions of mRNA and cell lines were found in all members of the MCM family, and MCMs were found to be significantly associated with pathological tumor grades in GC patients. Besides, higher mRNA expressions of MCM1/5/7 were found to be significantly associated with shorter overall survival (OS) and progression-free survival (FP) in GC patients, while higher mRNA expression of MCM4/6/9 were connected with favorable OS and FP. Moreover, a high mutation rate of MCMs (68%) was also observed in GC patients.

CONCLUSIONS

The results indicated that MCM1/5/7 were potential targets of precision therapy for patients with GC. And MCM4/6/9 were new biomarkers for the prognosis of GC. The results of the study will contribute to supplement the existing knowledge, and help to explore therapeutic targets and enhance the accuracy of prognosis for patients with GC.

Nesfatin-1 is a potential diagnostic biomarker for gastric cancer

The lack of reliable plasma biomarkers limits their use in the diagnosis of gastric cancer (GC). The current study aimed to determine whether plasma nesfatin-1 can be used as a novel non-invasive biomarker for the diagnosis of GC. The levels of nesfatin-1 in 40 patients with GC and 40 healthy individuals, who were selected from the Chaohu Hospital Affiliated to Anhui Medical University, were assessed. ELISA was used for the measurement of plasma nesfatin-1 levels, while immunohistochemistry was applied to determine Ki67 protein expression in GC and normal gastric tissues. The diagnostic value of plasma nesfatin-1 for GC was further assessed using receiver operating characteristic (ROC) curve analysis. The results revealed that, compared with the controls, the mean nesfatin-1 levels in patients with GC were significantly increased. Furthermore, the protein expression of Ki67 in GC tissue was significantly upregulated compared with that in normal gastric tissue. Plasma nesfatin-1 levels were also demonstrated to be correlated with Ki67 protein expression in GC tissues. Additionally, ROC curve analysis indicated the potential diagnostic value of nesfatin-1, and the area under the ROC curve (AUC) for nesfatin-1 was 0.857 (95% confidence interval, 0.769-0.946). At a threshold nesfatin-1 level of 1.075 ng/ml, the optimal sensitivity and specificity were 70.0 and 95.0%, respectively, in discriminating patients with GC from healthy controls. These results indicated that plasma nesfatin-1 may serve as a novel biomarker for the diagnosis of GC and determination of GC cell proliferation.

Genome-wide investigation of the clinical significance and prospective molecular mechanism of minichromosome maintenance protein family genes in patients with Lung Adenocarcinoma

Our current study is to identify clinical significance of minichromosome maintenance (MCM) gene expression in Lung Adenocarcinoma (LUAD) using genome-wide RNA sequencing (RNA-seq) dataset and bioinformatics analysis tools. The biological function and potential process for function of the MCM1-10 were identified by multiple bioinformatics analysis tools. Clinical significance and molecular mechanism of the MCM1-10 were investigated by the RNA-seq dataset of LUAD from The Cancer Genome Atlas. Functional assessment substantiated involvement of MCM1-10 in cell cycle progression and DNA replication, and co-expressed with each other. We also observed that the MCM1-10 were dysregulation in LUAD tumor tissues, and may be have diagnostic implications in LUAD. Prognosis analysis in TCGA and KM plotter cohorts suggest that high abundance of MCM5, MCM8 and MCM4 notably correlated to poor LUAD overall survival. Mechanistic exploration of MCM4, MCM5, and MCM8 by gene set enrichment analysis suggests that these genes may influence the LUAD prognosis by regulating the cell cycle, DNA replication and other multiple biological processes and pathways. In comclusion, our study suggests that MCM1-10 can serve as diagnostic biomarkers for LUAD patients. Of them, MCM4, MCM5, and MCM8 may act as potential prognostic indicators for LUAD.

Phenotypic transition of tumor cells between epithelial- and mesenchymal-like state during adaptation to acidosis

Acidic microenvironment is an important feature of solid tumors that contributes to malignant transformation. Low extracellular pH could promote epithelial-mesenchymal transition (EMT) thereby endowing tumor cells with higher invasive capability. However, the relation between EMT and tumor cell proliferation under long-term acidic condition is still not fully understood. Here, we show that tumor cells have undergone a phenotypic transition from EMT to mesenchymal-epithelial transition (MET) during adaptation to acidosis, and is closely related with cell proliferative state. Under early stage of acidic stress, tumor cells entered a non-cycling quiescent state with mesenchymal phenotype and expressed high level of stemness genes. Whereas, after long-term acid culture (2 months), acid-adapted cells resumed proliferating but lost mesenchymal phenotype. Further, our results show that the acid-adapted cells have distinct proliferative mechanism from non-acid cells, as the G1-S transcriptional factor E2F1 protein was not recovered in the adapted cells. Meanwhile, mini-chromosome maintenance 7 (MCM7) is shown to regulate the EMT to MET phenotypic transition, and is required for proliferation of the adapted cells under acidic condition. MCM7 Knockdown promoted mesenchymal phenotype and inhibited proliferation of the acid-adapted cells. While, MCM7 overexpression inhibited acid-induced EMT and supported tumor cell proliferation under acidic condition. Thus, our study provides evidence that tumor cells display phenotypic plasticity that allows them to survive acid stress.

Prognostic value of minichromosome maintenance mRNA expression in early-stage pancreatic ductal adenocarcinoma patients after pancreaticoduodenectomy

Background

The aim of the current study was to investigate the potential prognostic value of minichromosome maintenance (MCM) genes in patients with early-stage pancreatic ductal adenocarcinoma (PDAC) after pancreaticoduodenectomy by using the RNA-sequencing dataset from The Cancer Genome Atlas (TCGA).

Methods

An RNA-sequencing dataset of 112 early-stage PDAC patients who received a pancreaticoduodenectomy was obtained from TCGA. Survival analysis was used to identify potential prognostic values of MCM genes in PDAC overall survival (OS).

Results

Through mining public databases, we observed that MCM genes (MCM2, MCM3, MCM4, MCM5, MCM6, and MCM7) were upregulated in pancreatic cancer tumor tissue and have a strong positive coexpression with each other. Multivariate survival analysis indicated that a high expression of MCM4 significantly increased the risk of death in patients with PDAC, and time-dependent receiver operating characteristic analysis showed an area under the curve of 0.655, 0.587, and 0.509 for a 1-, 2-, and 3-year PDAC OS prediction, respectively. Comprehensive survival analysis of MCM4 using stratified and joint effects survival analysis suggests that MCM4 may be an independent prognostic indicator for PDAC OS. Gene set enrichment analysis indicated that MCM4 may participate in multiple biologic processes and pathways, including DNA replication, cell cycle, tumor protein p53, and Notch signaling pathways, thereby affecting prognosis of PDAC patients.

Conclusions

Our study indicates that MCM2–7 were upregulated in pancreatic cancer tumor tissues, and mRNA expression of MCM4 may serve as an independent prognostic indicator for PDAC OS prediction after pancreaticoduodenectomy.

Distinct Diagnostic and Prognostic Values of Minichromosome Maintenance Gene Expression in Patients with Hepatocellular Carcinoma

Background: The aim of the present study was to identify diagnostic and prognostic values of minichromosome maintenance (MCM) gene expression in patients with hepatocellular carcinoma (HCC).

Methods: The biological function of the MCM genes were investigated by bioinformatics analysis. The diagnostic and prognostic values of the MCM genes were investigated by using the data of HCC patients from the GSE14520 and The Cancer Genome Atlas (TCGA) databases.

Results: Bioinformatics analysis of the MCM genes substantiated that MCM2-7 genes were significantly enriched in DNA replication and cell cycle, and co-expressed with each other. These genes also co-expressed in HCC tumor tissue in both the GSE14520 and TCGA cohort. We also observed that the expression of the MCM2-7 genes was increased in tumor tissue, and diagnostic receiver operating characteristic analysis of MCM2-7 indicated that these genes could serve as sensitive diagnostic markers in HCC. Survival analysis in the GSE14520 cohort suggested that expression of MCM2, MCM4, MCM5, and MCM6 were significantly associated with hepatitis B virus-related HCC overall survival (OS). However, none of the MCM genes were associated with recurrence-free survival in the GSE14520 cohort. The validation cohort of TCGA suggested that the expression of MCM2, MCM6, and MCM7 were significantly correlated with HCC OS.

Conclusion: Our study indicated that MCM2-7 genes may be potential diagnostic biomarkers in patients with HCC. Among them, MCM2 and MCM6 may serve as potential prognostic biomarkers for HCC.

Five Novel Oncogenic Signatures Could Be Utilized as AFP-Related Diagnostic Biomarkers for Hepatocellular Carcinoma Based on Next-Generation Sequencing

BACKGROUND

Alpha-fetal protein (AFP) is an important conventional clinical diagnostic indicator of hepatocellular carcinoma (HCC). However, the utilization of AFP alone might yield deceptive results due to its limited sensitivity and accuracy.

AIMS

Our study was designed to investigate latent diagnostic biomarkers that could function as auxiliary clinical indicators of HCC and enhance the accuracy of joint diagnosis with AFP.

METHODS

We analyzed gene expression profiles and clinical data from HCC patients in The Cancer Genome Atlas database. Differentially expressed genes were identified, and a gene set enrichment analysis was conducted to uncover their biological functions and molecular processes. A weighted correlation network analysis and a protein-protein interaction analysis were performed to detect AFP-related biomarkers. The diagnostic performance of these biomarkers was verified using datasets from the GEO database. A diagnostic nomogram was established using the expression levels of potential biomarkers. Quantitative real-time PCR was performed using tissues from 16 HCC patients to validate the results.

RESULTS

Five AFP-related diagnostic biomarkers, CDT1, MCM7, NUDT1, CENPM, and HDAC11, were discovered. The diagnostic performance of these biomarkers and the nomogram were demonstrated to be excellent according to receiver operating characteristic curves. CDT1, MCM7, and NUDT1 were shown to be up-regulated in HCC tissues through quantitative real-time PCR.

CONCLUSIONS

We discovered five diagnostic biomarkers and established a nomogram as a complement to AFP in the diagnosis of HCC. Our results provide a more accurate diagnostic plan for HCC patients based on next-generation sequencing compared with AFP alone.