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

Deciphering roles of TRIMs as promising targets in hepatocellular carcinoma: current advances and future directions

Tripartite motif (TRIM) family is assigned to RING-finger-containing ligases harboring the largest number of proteins in E3 ubiquitin ligating enzymes. E3 ubiquitin ligases target the specific substrate for proteasomal degradation via the ubiquitin-proteasome system (UPS), which seems to be a more effective and direct strategy for tumor therapy. Recent advances have demonstrated that TRIM genes associate with the occurrence and progression of hepatocellular carcinoma (HCC). TRIMs trigger or inhibit multiple biological activities like proliferation, apoptosis, metastasis, ferroptosis and autophagy in HCC dependent on its highly conserved yet diverse structures. Remarkably, autophagy is another proteolytic pathway for intracellular protein degradation and TRIM proteins may help to delineate the interaction between the two proteolytic systems. In depth research on the precise molecular mechanisms of TRIM family will allow for targeting TRIM in HCC treatment. We also highlight several potential directions warranted further development associated with TRIM family to provide bright insight into its translational values in hepatocellular carcinoma.

P53 status, and G2/M cell cycle arrest, are determining factors in cell-death induction mediated by ELF-EMF in glioblastoma

The average survival of patients with glioblastoma is 12-15 months. Therefore, finding a new treatment method is important, especially in cases that show resistance to treatment. Extremely low-frequency electromagnetic fields (ELF-EMF) have characteristics and capabilities that can be proposed as a new cancer treatment method with low side effects. This research examines the antitumor effect of ELF-EMF on U87 and U251 glioblastoma cell lines. Flowcytometry determined the viability/apoptosis and distribution of cells in different phases of the cell cycle. The size of cells was assessed by TEM. Important cell cycle regulation genes mRNA expression levels were investigated by real-time PCR. ELF-EMF induced apoptosis in U87cells much more than U251 (15% against 2.43%) and increased G2/M cell population in U87 (2.56%, p value < 0.05), and S phase in U251 (2.4%) (data are normalized to their sham exposure). The size of U87 cells increased significantly after ELF-EMF exposure (overexpressing P53 in U251 cells increased the apoptosis induction by ELF-EMF). The expression level of P53, P21, and MDM2 increased and CCNB1 decreased in U87. Among the studied genes, MCM6 expression decreased in U251. Increasing expression of P53, P21 and decreasing CCNB1, induction of cell G2/M cycle arrest, and consequently increase in the cell size can be suggested as one of the main mechanisms of apoptosis induction by ELF-EMF; furthermore, our results demonstrate the possible footprint of P53 in the apoptosis induction by ELF-EMF, as U87 carry the wild type of P53 and U251 has the mutated form of this gene.

De novo MCM6 variants in neurodevelopmental disorders: a recognizable phenotype related to zinc binding residues

The minichromosome maintenance (MCM) complex acts as a DNA helicase during DNA replication, and thereby regulates cell cycle progression and proliferation. In addition, MCM-complex components localize to centrosomes and play an independent role in ciliogenesis. Pathogenic variants in genes coding for MCM components and other DNA replication factors have been linked to growth and developmental disorders as Meier-Gorlin syndrome and Seckel syndrome. Trio exome/genome sequencing identified the same de novo MCM6 missense variant p.(Cys158Tyr) in two unrelated individuals that presented with overlapping phenotypes consisting of intra-uterine growth retardation, short stature, congenital microcephaly, endocrine features, developmental delay and urogenital anomalies. The identified variant affects a zinc binding cysteine in the MCM6 zinc finger signature. This domain, and specifically cysteine residues, are essential for MCM-complex dimerization and the induction of helicase activity, suggesting a deleterious effect of this variant on DNA replication. Fibroblasts derived from the two affected individuals showed defects both in ciliogenesis and cell proliferation. We additionally traced three unrelated individuals with de novo MCM6 variants in the oligonucleotide binding (OB)-fold domain, presenting with variable (neuro)developmental features including autism spectrum disorder, developmental delay, and epilepsy. Taken together, our findings implicate de novo MCM6 variants in neurodevelopmental disorders. The clinical features and functional defects related to the zinc binding residue resemble those observed in syndromes related to other MCM components and DNA replication factors, while de novo OB-fold domain missense variants may be associated with more variable neurodevelopmental phenotypes. These data encourage consideration of MCM6 variants in the diagnostic arsenal of NDD.

Construction and validation of prognostic signature for hepatocellular carcinoma basing on hepatitis B virus related specific genes

BACKGROUND

Hepatocellular carcinoma (HCC) is a frequent primary liver cancer, and it is one of the leading cause of cancer-related deaths. Hepatitis B virus (HBV) infection is a crucial risk factor for HCC. Thus, this study aimed to explore the prognostic role of HBV-positive HCC related specific genes in HCC.

METHODS

The HCC related data were downloaded from three databases, including The Cancer Genome Atlas (TCGA), International Cancer Genome Consortium (ICGC), and Gene Expression Omnibus (GEO). Univariate Cox regression analysis and LASSO Cox regression analysis were conducted to build the Risk score. Multivariate Cox regression analysis and survival analysis determined the independent prognostic indicators.

RESULTS

After cross analysis of differentially expressed genes (DEGs), we have identified 106 overlapped DEGs, which were probably HBV-positive HCC related specific genes. These 106 DEGs were significantly enriched in 213 GO terms and 8 KEGG pathways. Among that, 11 optimal genes were selected to build a Risk score, and Risk score was an independent prognostic factor for HCC. High risk HCC patients had worse OS. Moreover, five kinds of immune cells were differentially infiltrated between high and low risk HCC patients.

CONCLUSION

The prognostic signature, based on HMMR, MCM6, TPX2, KIF20A, CCL20, RGS2, NUSAP1, FABP5, FZD6, PBK, and STK39, is conducive to distinguish different prognosis of HCC patients.

TRIM proteins in hepatocellular carcinoma

The tripartite motif (TRIM) protein family is a highly conserved group of E3 ligases with 77 members known in the human, most of which consist of a RING-finger domain, one or two B-box domains, and a coiled-coil domain. Generally, TRIM proteins function as E3 ligases to facilitate specific proteasomal degradation of target proteins. In addition, E3 ligase independent functions of TRIM protein were also reported. In hepatocellular carcinoma, expressions of TRIM proteins are both regulated by genetic and epigenetic mechanisms. TRIM proteins regulate multiple biological activities and signaling cascades. And TRIM proteins influence hallmarks of HCC. This review systematically demonstrates the versatile roles of TRIM proteins in HCC and helps us better understand the molecular mechanism of the development and progression of HCC.

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.

MCM6 indicates adverse tumor features and poor outcomes and promotes G1/S cell cycle progression in neuroblastoma

Background

Minichromosome maintenance complex component 6 (MCM6), as an important replication permission factor, is involved in the pathogenesis of various tumors. Here we studied the expression of MCM6 in neuroblastoma and its influence on tumor characteristics and prognosis.

Methods

Publicly available datasets were used to explore the influence of the differential expression of MCM6 on neuroblastoma tumor stage, risk and prognosis. In cell experiments, human neuroblastoma cell lines SK-N-SH and SK-N-BE [ (2)] were utilized to verify the ability of MCM6 to promote cell proliferation, migration and invasion. We further explored the possible molecular mechanism of MCM6 affecting the phenotype of neuroblastoma cells by mutual verification of RNA-seq and western blotting, and flow cytometry to inquire about its potential specific roles in the cell cycle.

Results

Through multiple datasets mining, we found that high expression of MCM6 was positively correlated with elevated tumor stage, high risk and poor prognosis in neuroblastoma. At the cellular level, neuroblastoma cell proliferation, migration and invasion were significantly inhibited after MCM6 was interfered by siRNA. Mutual verification of RNA-seq and western blotting suggested that the downstream cell cycle-related genes were differentially expressed after MCM6 interference. Flow cytometric analysis revealed that neuroblastoma cells were blocked in G1/S phase after MCM6 interference.

Conclusion

MCM6 is considered to be the driving force of G1/S cell cycle progression, and it is also a prognostic marker and a potential novel therapeutic target in neuroblastoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08344-z.

Systemic Analysis of the DNA Replication Regulator MCM Complex in Ovarian Cancer and Its Prognostic Value

Microliposome maintenance (MCM) 2, MCM3, MCM4, MCM5, MCM6, and MCM7 are DNA replication regulators and are involved in the progression of multiple cancer types, but their role in ovarian cancer is still unclear. The purpose of this study is to clarify the biological function and prognostic value of the MCM complex in ovarian cancer (OS) progression. We analyzed DNA alterations, mRNA and protein levels, protein structure, PPI network, functional enrichment, and prognostic value in OC based on the Oncomine, cBioPortal, TCGA, CPTAC, PDB, GeneMANIA, DAVID, KEGG, and GSCALite databases. The results indicated that the protein levels of these DNA replication regulators were increased significantly. Moreover, survival analysis showed a prognostic signature based on the MCM complex, which performed moderately well in terms of OS prognostic prediction. Additionally, protein structure, functional enrichment, and PPI network analyses indicated that the MCM complex synergistically promoted OC progression by accelerating DNA replication and the cell cycle. In conclusion, our study suggested that the MCM complex might be a potential target and prognostic marker for OC patients.

Deciphering the effects of PYCR1 on cell function and its associated mechanism in hepatocellular carcinoma

Overexpression of pyrroline-5-carboxylate reductase 1 (PYCR1) has been associated with the development of certain cancers; however, no studies have specifically examined the role of PYCR1 in hepatocellular carcinoma (HCC). Based on The Cancer Genome Atlas expression array and meta-analysis conducted using the Gene Expression Omnibus database, we determined that PYCR1 was upregulated in HCC compared to adjacent nontumor tissues (P < 0.05). These data were verified using quantitative real-time polymerase chain reaction, western blotting, and immunohistochemistry analysis. Additionally, patients with low PYCR1 expression showed a higher overall survival rate than patients with high PYCR1 expression. Furthermore, PYCR1 overexpression was associated with the female sex, higher levels of alpha-fetoprotein, advanced clinical stages (III and IV), and a younger age (< 45 years old). Silencing of PYCR1 inhibited cell proliferation, invasive migration, epithelial-mesenchymal transition, and metastatic properties in HCC in vitro and in vivo. Using RNA sequencing and bioinformatics tools for data-dependent network analysis, we found binary relationships among PYCR1 and its interacting proteins in defined pathway modules. These findings indicated that PYCR1 played a multifunctional role in coordinating a variety of biological pathways involved in cell communication, cell proliferation and growth, cell migration, a mitogen-activated protein kinase cascade, ion binding, etc. The structural characteristics of key pathway components and PYCR1-interacting proteins were evaluated by molecular docking, and hotspot analysis showed that better affinities between PYCR1 and its interacting molecules were associated with the presence of arginine in the binding site. Finally, a candidate regulatory microRNA, miR-2355-5p, for PYCR1 mRNA was discovered in HCC. Overall, our study suggests that PYCR1 plays a vital role in HCC pathogenesis and may potentially serve as a molecular target for HCC treatment.

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.

Three novel circRNAs upregulated in tissue and plasma from hepatocellular carcinoma patients and their regulatory network

Background

The regulatory roles of circular RNAs (circRNAs) in tumorigenesis have attracted increasing attention. However, novel circRNAs with the potential to be used as serum/plasma biomarkers and their regulatory mechanism in the pathogenesis of hepatocellular carcinoma (HCC) remain explored.

Methods

CircRNA expression profiles of tumor tissues and plasma samples from HCC patients were compiled and jointly analyzed. CircRNA–miRNA–mRNA interactions were predicted by bioinformatics tools. The expression of interacting miRNAs and mRNA was verified in independent datasets. Survival analysis and pathway enrichment analysis were conducted on hub genes.

Results

We identified three significantly up-regulated circRNAs (hsa_circ_0009910, hsa_circ_0049783, and hsa_circ_0089172) both in HCC tissues and plasma samples. Two of them were validated to be indeed circular and could be excreted from hepatoma cells. We further revealed four miRNAs (hsa-miR-455-5p, hsa-miR-615-3p, hsa-miR-18a-3p, hsa-miR-4524a-3p) that targeting circRNAs and expressed in human HCC samples, and 95 mRNAs targeted by miRNAs and significantly up-regulated in two HCC cohorts. A protein-protein interaction network revealed 19 hub genes, 12 of them (MCM6, CCNB1, CDC20, NDC80, ZWINT, ASPM, CENPU, MCM3, MCM5, ECT2, CDC7, and DLGAP5) were associated with reduced survival in two HCC cohorts. KEGG, Reactome, and Wikipathway enrichment analysis indicated that the hub genes mainly functioned in DNA replication and cell cycle.

Conclusions

Our study uncovers three novel deregulated circRNAs in tumor and plasma from HCC patients and provides an insight into the pathogenesis from the circRNA–miRNA–mRNA regulatory network.