Regulation of SLD5 gene expression by miR-370 during acute growth of cancer cells

Circ-NMNAT1 Drives Tumor Progression in Bladder Cancer by Modulating the miR-370-3p/ATXN2L Axis

The relationship between circular RNAs (circRNAs) and tumor growth and metastasis is increasingly well-established. In this study, we sought to shed light on circ-NMNAT1's potential molecular mechanisms in bladder cancer (BCa). circ-NMNAT1, miR-370-3p, and ATXN2L expression profiles were explored using RT-qPCR and/or Western blot techniques. Cell proliferation was detected by MTT and colony formation assay. Transwell assay was used to detect the migration and invasion ability of cells. Western Blot was used to detect the protein expression level of ATXN2L. The targeting relationship between miR-370-3p and circ-NMNAT1 or ATXN2L was confirmed by dual luciferase reporter gene and RIP assay. A xenograft tumor model was created to investigate circ-NMNAT1's function in BCa in vivo. The high expression of circ-NMNAT1 was measured in BCa. circ-NMNAT1 bound competitively to miR-370-3p and downregulated miR-370-3p expression. After knocking down circ-NMNAT1, the proliferation ability of EJ cells was significantly inhibited, and the number of cell colonies was (80.00 ± 7.10). The number of migrated and invaded cells was significantly reduced by (35.49 ± 0.05)% and (59.00 ± 0.04)%, respectively, after silencing circ-NMNAT1. In addition, downregulation of circ-NMNAT1 also significantly increased the apoptosis rate of EJ cells by (23.55 ± 2.95)%. Knockdown of miR-370-3p or overexpression of ATXN2L reduced the effect of circ-NMNAT1 silencing on BCa cells. The promoting effect of circ-NMNAT1 on BCa progression was further validated in vivo tumor models. The weight and volume of the tumor were significantly inhibited after circ-NMNAT1 knockdown, which were (87.50 ± 20.40) mg and (238.90 ± 21.38) mm3, respectively. Circ-NMNAT1 is highly expressed in BCa and promotes the proliferation, migration, and invasion of BCa cells by regulating the miR-370-3p/ATXN2L axis, thereby accelerating the progression of BCa. Our results suggest that circ-NMNAT1 may be a new therapeutic target for BCa.

Unwinding the Role of the CMG Helicase in Inborn Errors of Immunity

Inborn errors of immunity (IEI) are a collection of diseases resulting from genetic causes that impact the immune system through multiple mechanisms. Natural killer cell deficiency (NKD) is one such IEI where natural killer (NK) cells are the main immune lineage affected. Though rare, the deficiency of several genes has been described as underlying causes of NKD, including MCM4, GINS1, MCM10 , and GINS4 , all of which are involved in the eukaryotic CMG helicase. The CMG helicase is made up of C DC45 – M CM – G INS and accessory proteins including MCM10. The CMG helicase plays a critical role in DNA replication by unwinding the double helix and enabling access of polymerases to single-stranded DNA, and thus helicase proteins are active in any proliferating cell. Replication stress, DNA damage, and cell cycle arrest are among the cellular phenotypes attributed to loss of function variants in CMG helicase proteins. Despite the ubiquitous function of the CMG helicase, NK cells have an apparent susceptibility to the deficiency of helicase proteins. This review will examine the role of the CMG helicase in inborn errors of immunity through the lens of NKD and further discuss why natural killer cells can be so strongly affected by helicase deficiency.

GINS4 suppresses ferroptosis by antagonizing p53 acetylation with Snail

Ferroptosis is an iron-dependent oxidative, nonapoptotic form of regulated cell death caused by the destruction of redox homeostasis. Recent studies have uncovered complex cellular networks that regulate ferroptosis. GINS4 is a promoter of eukaryotic G1/S-cell cycle as a regulator of initiation and elongation of DNA replication, but little is known about its impact on ferroptosis. Here, we found that GINS4 was involved in the regulation of ferroptosis in lung adenocarcinoma (LUAD). CRISPR/Cas9-mediated GINS4 KO facilitated ferroptosis. Interestingly, depletion of GINS4 could effectively induce G1, G1/S, S, and G2/M cells to ferroptosis, especially for G2/M cells. Mechanistically, GINS4 suppressed p53 stability through activating Snail that antagonized the acetylation of p53, and p53 lysine residue 351 (K351 for human p53) was the key site for GINS4-suppressed p53-mediated ferroptosis. Together, our data demonstrate that GINS4 is a potential oncogene in LUAD that functions to destabilize p53 and then inhibits ferroptosis, providing a potential therapeutic target for LUAD.

Recent findings on miR‑370 expression, regulation and functions in cancer (Review)

MicroRNAs (miRNAs/miRs) are a group of small non‑coding RNAs that serve as post‑transcriptional gene modulators. miRNAs have been demonstrated to serve a pivotal role in carcinogenesis and the dysregulated expression of miRNAs is a well‑understood characteristic of cancer. In recent years, miR‑370 has been established as a key miRNA in various cancers. The expression of miR‑370 is dysregulated in various types of cancer and varies markedly across different tumor types. miR‑370 can regulate multiple biological processes, including cell proliferation, apoptosis, migration, invasion, as well as cell cycle progression and cell stemness. Moreover, it has been reported that miR‑370 affects the response of tumor cells to anticancer treatments. Additionally, the expression of miR‑370 is modulated by multiple factors. The present review summarizes the role and mechanism of miR‑370 in tumors, and demonstrates its potential as a molecular marker for cancer diagnosis and prognosis.

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.

MicroRNA-133a-3p Inhibits Lung Adenocarcinoma Development and Cisplatin Resistance through Targeting GINS4

GINS subunit complex 4 (GINS4) is fundamental to DNA replication and G1/S phase transition of the cell cycle in eukaryotes. Further, recent studies implied that GINS4 can mediate the progression of several tumors, but its mechanism in lung adenocarcinoma (LUAD) is not clarified. Therefore, the role of GINS4 in LUAD was explored. miR-133a-3p and GINS4 mRNA expression were tested through qRT-PCR. Protein levels of the two genes were assayed by Western blot. Their targeting relationship was predicted and verified by bioinformatics prediction and dual-luciferase analysis. The functions of miR-133a-3p and GINS4 in LUAD were evaluated by Transwell, wound healing, CCK-8, and flow cytometry assays. MTT assay and caspase-3 activity detection were utilized to measure the regulation of miR-133a-3p/GINS4 in the cisplatin sensitivity of LUAD cells. The results showed that GINS4 was highly expressed in LUAD cells (p < 0.05). miR-133a-3p, the upstream gene of GINS4 in LUAD, negatively mediated GINS4 expression. Moreover, overexpressing GINS4 enhanced the proliferative, migratory, and invasive abilities of LUAD cells and inhibited cell apoptosis and the sensitivity to cisplatin, while overexpressing miR-133a-3p caused the contrary results. However, the promoting effects of GINS4 overexpression on LUAD could be offset by miR-133a-3p overexpression. miR-133a-3p could regulate malignant behaviors and cisplatin sensitivity of LUAD cells through negatively regulating GINS4. In conclusion, our findings demonstrated that GINS4 was overexpressed in LUAD and promoted the malignant behavior of LUAD cells. Moreover, miR-133a-3p could negatively regulate GINS4, thereby suppressing the malignant progression and increasing the cisplatin sensitivity of LUAD.

A pan-cancer analysis of GINS complex subunit 4 to identify its potential role as a biomarker in multiple human cancers

This study was initiated to explore the expression variation, clinical significance, and biological importance of the GINS complex subunit 4 (GINS4) in different human cancers as a shared biomarker via pan-cancer analysis through different platforms including UALCAN, Kaplan Meier (KM) plotter, TNMplot, GENT2, GEPIA, DriverDBv3, Human Protein Atlas (HPA), MEXPRESS, cBioportal, STRING, DAVID, MuTarge, Enrichr, TIMER, and CTD. Our findings have verified the up-regulation of GINS4 in 24 major subtypes of human cancers, and its overexpression was found to be substantially associated with poor overall survival (OS), relapse-free survival (RFs), and metastasis in ESCA, KIRC, LIHC, LUAD, and UCEC. This suggested that GINS4 plays a significant role in the development and progression of these five cancers. Furthermore, we noticed that GINS4 is also overexpressed in ESCA, KIRC, LIHC, LUAD, and UCEC patients with different clinicopathological characteristics. Enrichment analysis revealed the involvement of GINS4 associated genes in a variety of diverse GO and KEGG terms. We also explored few significant correlations between GINS4 expression and promoter methylation, genetic alterations, CNVs, other mutant genes, tumor purity, and immune cells infiltration. In conclusion, our results elucidated that GINS4 can serve as a shared diagnostic, prognostic biomarker, and a potential therapeutic target in ESCA, KIRC, LIHC, LUAD, and UCEC patients with different clinicopathological characteristics.

In silico recognition of a prognostic signature in basal-like breast cancer patients

Background

Triple-negative breast cancers (TNBCs) display poor prognosis, have a high risk of tumour recurrence, and exhibit high resistance to drug treatments. Based on their gene expression profiles, the majority of TNBCs are classified as basal-like breast cancers. Currently, there are not available widely-accepted prognostic markers to predict outcomes in basal-like subtype, so the selection of new prognostic indicators for this BC phenotype represents an unmet clinical challenge.

Results

Here, we attempted to address this challenging issue by exploiting a bioinformatics pipeline able to integrate transcriptomic, genomic, epigenomic, and clinical data freely accessible from public repositories. This pipeline starts from the application of the well-established network-based SWIM methodology on the transcriptomic data to unveil important (switch) genes in relation with a complex disease of interest. Then, survival and linear regression analyses are performed to associate the gene expression profiles of the switch genes with both the patients’ clinical outcome and the disease aggressiveness. This allows us to identify a prognostic gene signature that in turn is fed to the last step of the pipeline consisting of an analysis at DNA level, to investigate whether variations in the expression of identified prognostic switch genes could be related to genetic (copy number variations) or epigenetic (DNA methylation differences) alterations in their gene loci, or to the activities of transcription factors binding to their promoter regions. Finally, changes in the protein expression levels corresponding to the so far identified prognostic switch genes are evaluated by immunohistochemical staining results taking advantage of the Human Protein Atlas.

Conclusion

The application of the proposed pipeline on the dataset of The Cancer Genome Atlas (TCGA)-Breast Invasive Carcinoma (BRCA) patients affected by basal-like subtype led to an in silico recognition of a basal-like specific gene signature composed of 11 potential prognostic biomarkers to be further investigated.

Circular RNA CCDC66 Improves Murine Double Minute 4 (MDM4) Expression through Targeting miR-370 in Colorectal Cancer

Introduction

Colorectal cancer (CRC), a common digestive tract tumor that contains colon and rectal cancer, is one of the three most common cancers globally. circRNAs are involved in the occurrence and development of CRC, but the mechanism of how they participate in this process remains unclear.

Methods

We adopted PCR for expression measure, CCK-8 for cell proliferation detection, Transwell for cell migration and invasion detection, and dual-luciferase reporter assays to detect the potential downstream targets of CCDC66 in CRC.

Results

This study showed that circRNA CCDC66 was overexpressed in CRC tissues, and after knockdown, it inhibited the proliferation, migration, and invasion of CRC cells (RKO and HCT-116) in vitro. In addition, the dual-luciferase reporter assay showed that there was a binding site between circCCDC66 and miR-370, as well as between miR-370 and murine double minute 4 (MDM4). That is, circCCDC66 upregulated the expression of MDM4 through competitively binding to miR-370. The expression of circCCDC66 in CRC tissues was positively correlated with MDM4 and negatively correlated with miR-370.

Conclusion

In summary, our results indicate that circCCDC66 is a key upregulation of CRC. circCCDC66 upregulates MDM4 through competitive binding to miR-370, thereby enhancing the metastatic ability of CRC cells and promoting the development of CRC.

Multiple RNA virus matrix proteins interact with SLD5 to manipulate host cell cycle

The matrix protein of many enveloped RNA viruses regulates multiple stages of viral life cycle and has the characteristics of nucleocytoplasmic shuttling. We have previously demonstrated that matrix protein 1 (M1) of an RNA virus, influenza virus, blocks host cell cycle progression by interacting with SLD5, a member of the GINS complex, which is required for normal cell cycle progression. In this study, we found that M protein of several other RNA viruses, including VSV, SeV and HIV, interacted with SLD5. Furthermore, VSV/SeV infection and M protein of VSV/SeV/HIV induced cell cycle arrest at G0/G1 phase. Importantly, overexpression of SLD5 partially rescued the cell cycle arrest by VSV/SeV infection and VSV M protein. In addition, SLD5 suppressed VSV replication in vitro and in vivo, and enhanced type Ⅰ interferon signalling. Taken together, our results suggest that targeting SLD5 by M protein might be a common strategy used by multiple enveloped RNA viruses to block host cell cycle. Our findings provide new mechanistic insights for virus to manipulate cell cycle progression by hijacking host replication factor SLD5 during infection.

GINS Complex Subunit 2 Facilitates Gastric Adenocarcinoma Proliferation and Indicates Poor Prognosis

Gastric cancer is the one of the most lethal malignancies of digestive system. Identifying molecular biomarkers is invaluable in help predicting clinical outcomes and developing targeted chemotherapies. GINS complex subunit 2 (GINS2) plays an essential role in the initiation and elongation of DNA replication. Although there have been studies revealing the prognostic significance of GINS2 in breast cancer and lung cancer, its involvement and function in gastric cancer need to be elucidated. We retrospectively enrolled a cohort of gastric adenocarcinoma patients after surgical resection (n = 123). By analyzing the mRNA and protein levels of GINS2 in tissue samples, we found that GINS2 presented a higher expression in tumor tissues than in adjacent normal stomach tissues. Besides, GINS2 level was positively correlated with tumor size and gastric adenocarcinoma tumor stage, implying its potential role as a tumor promoter. Univariate and multivariate analyses identified that patients with lower GINS2 showed a better overall survival compared to those with higher GINS2 expression. In addition, cellular and xenograft experiments confirmed the role of GINS2 in facilitating tumor proliferation both in vitro and in vivo. To our knowledge, this is the initial finding on GINS2 in promoting gastric adenocarcinoma progression. In conclusion, our study revealed a pro-oncogenic role of GINS2 in gastric cancer.

Overexpression of GINS4 Is Associated With Tumor Progression and Poor Survival in Hepatocellular Carcinoma

Purpose

Our research was aimed to identify the expression, clinical value and biological significance of GINS complex subunit 4 (GINS4) in hepatocellular carcinoma (HCC).

Materials and Methods

GINS4 was initially screened through weighted gene co-expression network analysis (WGCNA). The TCGA, GEO, and TIMER databases were applied for analyzing the GINS4 mRNA expression in HCC. GINS4 protein levels were detected via immunohistochemistry (IHC). Receiver operating characteristic (ROC) curve was applied for estimating the diagnostic significance of GINS4 in HCC. Kaplan-Meier plots, Cox model, and nomogram were used to assess the prognostic performance of GINS4 in HCC. Nomogram validation was conducted through time-dependent ROC and decision curve analysis (DCA). The Wanderer, UALCAN, and DiseaseMeth databases were utilized to identify GINS4 methylation levels in HCC. Genes co-expressed with GINS4 in HCC were estimated through the TCGA, cBioPortal, and GEPIA. GO, KEGG, and GSEA unraveled the possible biological mechanisms of GINS4 in HCC.

Results

WGCNA confirmed that GINS4 was one of hub genes significantly associated with histological grade of HCC. Multiple databases confirmed the significant upregulation of GINS4 in HCC tissues compared with non-tumor controls. IHC analysis of 35 HCC patients demonstrated that overexpressed GINS4 positively correlated with advanced TNM stage and poor pathological differentiation. GINS4 could effectively differentiate HCC cases from healthy individuals, with an AUC of 0.865. Increased GINS4 expression predicted unsatisfactory prognosis in HCC patients, especially in age >60 years, histological grade 1, HBV infection-negative, and occurring relapse subgroup. Nomogram incorporating GINS4 level and TNM stage displayed satisfactory predictive accuracy and clinical utility in predicting HCC prognosis. Upregulated GINS4 exhibited hypomethylated levels in HCC. Functional analysis indicated that GINS4 potentially positively modulated cell cycle and PI3K/AKT/mTOR pathway.

Conclusion

GINS4 is overexpressed in HCC and is correlated with undesirable survival of HCC patients.

Expression and prognosis analysis of GINS subunits in human breast cancer

ABSTRACT

GINS subunits, a protein complex composed of GINS1, GINS2, GINS3 and GINS4 in the human genome and the expression level of each GINS subunits plays an important role in different human cancers. As one of the most common malignancies after lung cancer in the world, precise biomarkers for early diagnosis and treatment in breast cancer are important. The purpose of our study was to elucidate the expression and prognostic value of GINS subunits in breast cancer.The purpose of present study was to explore the expression level of GINS subunits in breast cancer patients.In the present study, we investigated the gene alteration, gene expression and potential prognostic value of GINS subunits by using the Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN, cBioPortal, and bc-GenExMiner databases. Then, the GeneMANIA database was used to show the genes that associated with GINS subunits. Furthermore, gene ontology pathway analysis was conducted by using the Metascape database. Finally, immune infiltration analysis in GINS subunits were evaluated using the Tumor Immune Estimation Resource (TIMER) database.Our analyses demonstrated that the expression levels of different GINS subunits were different between breast cancer and normal breast tissues. The expression levels of GINS1, GINS2, and GINS4 were significantly higher in breast cancer tissues than in normal tissues. Survival analysis revealed that increased the expression levels of GINS subunits were associated with poor prognoses in all patients with breast cancer. Gene ontology pathway enrichment analysis of the GINS subunits suggested that GINS subunits involved in pathways including the cell cycle checkpoint, DNA replication and other meaningful signaling pathways.We systemically analyzed the expression, prognostic, clinicopathologic values, and potential functional networks of GINS subunits in breast cancer. Our findings showed that individual GINS subunits could be new potential prognostic biomarkers for breast cancer. However, further verification studies are still needed to prove the clinical value of GINS subunits in breast cancer patients.

MicroRNAs and target molecules in bladder cancer

Bladder cancer (BC) is considered as one of the most common malignant tumors in humans with complex pathogenesis including gene expression variation, protein degradation, and changes in signaling pathways. Many studies on involved miRNAs in BC have demonstrated that they could be used as potential biomarkers in the prognosis, response to treatment, and screening before the cancerous phenotype onset. MicroRNAs (miRNAs) regulate many cellular processes through their different effects on special targets along with modifying signaling pathways, apoptosis, cell growth, and differentiation. The diverse expression of miRNAs in cancerous tissues could mediate procedures leading to the oncogenic or suppressor behavior of certain genes in cancer cells. Since a specific miRNA may have multiple targets, an mRNA could also be regulated by multiple miRNAs which further demonstrates the actual role of miRNAs in cancer. In addition, miRNAs can be utilized as biomarkers in some cancers that cannot be screened in the early stages. Hence, finding blood, urine, or tissue miRNA biomarkers by novel or routine gene expression method could be an essential step in the prognosis and control of cancer. In the present review, we have thoroughly evaluated the recent findings on different miRNAs in BC which can provide comprehensive information on better understanding the role of diverse miRNAs and better decision making regarding the new approaches in the diagnosis, prognosis, prevention, and treatment of BC.

Expression Profile of GINS Complex Predicts the Prognosis of Pancreatic Cancer Patients

BACKGROUND

The GINS complex has been implicated in the prognosis of various cancers. It comprises four subunits, encoded by GINS1, GINS2, GINS3, and GINS4 genes. Based on the current understanding, no report exists on the role of the GINS complex in pancreatic cancer.

METHODS

We employed various bioinformatics databases including GEPIA, UALCAN, GEPIA2, and Kaplan Meier Plotter to identify the expression profile of the four genes (GINS1, GINS2, GINS3, and GINS4), their correlation with pancreatic cancer grade as well as their prognostic value of in pancreatic cancer. Western blotting and qRT-PCR analyses were conducted to verify the expression profiles of the four genes in pancreatic cancer. CCK8 and EdU cell experiments were conducted to reveal the role played by the four genes in pancreatic cancer cell proliferation.

RESULTS

Based on GEPIA, Western blotting, and qRT-PCR analyses, all the four genes in the GINS complex were overexpressed in pancreatic cancer. Notably, the expression of each member was significantly associated with pancreatic cancer grade. The prognostic analysis revealed that not only the whole GINS complex but also each individual were prognostic biomarkers for pancreatic cancer. CCK8 and EdU experiments demonstrated that inhibition of the expression of each GINS member lowered pancreatic cancer cell proliferation.

CONCLUSION

This work implicated GINS1, GINS2, GINS3, and GINS4 genes as critical prognostic markers for pancreatic cancer.

Mining the prognostic significance of the GINS2 gene in human breast cancer using bioinformatics analysis

A number of studies have demonstrated the crucial functions of GINS2 within the GINS complex in various types of cancer. However, the molecular mechanisms and prognostic value of GINS2 in breast cancer remain unknown. The present study used; BC-GenExMiner, COSMIC, UCSC Xena, The Human Protein Atlas, GEPIA, cBioPortal, GeneMANIA, TIMER and Oncomine, in order to investigate gene expression, co-expression, clinical parameters and mutations in GINS2 in patients with breast cancer. Furthermore, the present study assessed the prognostic value of GINS2 in patients with breast cancer via the Kaplan-Meier plotter database. The results of the present study demonstrated that the mRNA levels of GINS2 were significantly higher in breast cancer tissue compared with normal tissue. In addition, high mRNA expression levels of GINS2 were associated with high Scarff-Bloom-Richardson status grades, a basal-like status and age (≤51 years); however, it was not associated with lymph node metastasis. The survival analysis revealed that increased GINS2 mRNA levels were associated with a worse prognosis for relapse-free survival in all patients with breast cancer, particularly in those with estrogen receptor-positive and progesterone receptor-positive subtypes. In addition, a positive association between the GINS2, CENPM and MCM4 genes was confirmed. The results of the present study suggest that GINS2 could be used as a potential prognostic biomarker for breast cancer. Nevertheless, further studies are necessary to confirm the effects of GINS2 on the pathogenesis and development of patients with breast cancer.

Tissue-Specific Requirement for the GINS Complex During Zebrafish Development

Efficient and accurate DNA replication is particularly critical in stem and progenitor cells for successful proliferation and survival. The replisome, an amalgam of protein complexes, is responsible for binding potential origins of replication, unwinding the double helix, and then synthesizing complimentary strands of DNA. According to current models, the initial steps of DNA unwinding and opening are facilitated by the CMG complex, which is composed of a GINS heterotetramer that connects Cdc45 with the mini-chromosome maintenance (Mcm) helicase. In this work, we provide evidence that in the absence of GINS function DNA replication is cell autonomously impaired, and we also show that gins1 and gins2 mutants exhibit elevated levels of apoptosis restricted to actively proliferating regions of the central nervous system (CNS). Intriguingly, our results also suggest that the rapid cell cycles during early embryonic development in zebrafish may not require the function of the canonical GINS complex as neither zygotic Gins1 nor Gins2 isoforms seem to be present during these stages.

GINS complex subunit 4, a prognostic biomarker and reversely mediated by Krüppel-like factor 4, promotes the growth of colorectal cancer

GINS complex subunit 4 (GINS4) is essential for DNA replication initiation and elongation in the G₁ /S phase cell cycle in eukaryotes, however, its functional roles and molecular mechanisms remain unclear in many aspects. Our study was designed to investigate the clinical significance, biological function, and molecular mechanism of GINS4 in colorectal cancer (CRC). First, we confirmed that GINS4 expression was significantly overexpressed in CRC cells and tissues. The immunohistochemical results in tissue microarray from 106 CRC patients showed that a high level of GINS4 expression was positively correlated with advanced T stage, higher tumor TNM stage, and poor differentiation. The results from univariate and multivariate survival analysis models based on 106 CRC patients revealed that GINS4 might serve as an independent prognostic indicator for overall survival and disease-free survival of CRC patients. Moreover, downregulated GINS4 can inhibit growth and the cell cycle and accelerate cell apoptosis progression in vitro as well as inhibit tumorigenesis in vivo. Besides, our results also indicated that Krüppel-like factor 4 (KLF4) can negatively regulate GINS4 expression at the transcriptional level and the KLF/GINS4 pathway might play a vital role in the growth and prognosis of CRC.

lncRNA BCAR4 sponges miR‑370‑3p to promote bladder cancer progression via Wnt signaling

Accumulating evidence suggests that the aberrant expression of long non-coding RNAs (lncRNAs) is involved in the initiation, development and metastasis of bladder cancer (BC). Although several differentially expressed lncRNAs have been identified via lncRNA expression profiling of BC tissues, their functions and the molecular mechanisms underlying these functions remain to be fully elucidated. In the present study, elevated levels of lncRNA breast cancer anti-estrogen receptor 4 (BCAR4) were identified in BC tissues compared with matched healthy tissues. Silencing of BCAR4 inhibited cell proliferation and induced apoptosis in BC cell lines 5637 and T24. Downregulation of BCAR4 led to the inactivation of Wnt signaling. Mechanistically, BCAR4 directly sponged microRNA (miR)-370-3p and elevated Wnt7a expression. Endogenous expression of Wnt7a reversed BCAR4 silencing-mediated cell growth arrest and induction of apoptosis in BC cells accompanied with a re-activation of Wnt signaling. Reverse transcription-quantitative PCR indicated that there was a strong association between BCAR4, miR-370-3p and Wnt7a expression in tumors from patients with BC compared with healthy control tissues. In conclusion, results of the present study suggest that lncRNA BCAR4 promoted proliferation and survival of BC cells via downregulation of miR-370-3p. Therefore, lncRNA BCAR4 may be a lncRNA of oncogenic potential in BC.

The novel GINS4 axis promotes gastric cancer growth and progression by activating Rac1 and CDC42

Rationale: As a component of GINS complex, GINS4 is essential for initiating DNA replication and elongation of the cell cycle G1/S phase in eukaryotes and plays a vital role in normal physiological processes. However, the precise functions and regulation mechanisms of GINS4 in human tumors remain elusive.

Methods: GINS4 expression was analyzed in gastric cancer tissues by qRT-PCR and western blotting, and its clinical relevance was studied using TMA. The biological functions of GINS4 were detected in vitro and in vivo. cDNA array, co-IP, GST pull-down and GTPase activation assays were performed to investigate the downstream regulation mechanism of GINS4. Upstream regulation mechanism of GINS4 was explored and demonstrated by circRNA sequencing, bioinformatics analysis, luciferase reporter assay and rescue experiments.

Results: Strikingly high GINS4 expression was detected in gastric cancer tissues and correlated with poor differentiation, advanced tumor stage, invasion depth and lymph node metastasis. GINS4 promoted cell growth and metastasis in vitro and in vivo, and suppressed cell apoptosis in vitro. Mechanistically, GINS4 activated Rac1/CDC42 through directly binding to Rac1/CDC42, thereby activating their downstream pathways. Furthermore, circMLLT10 acts as a miR-509-3-5p sponge to attenuate its repressive effect on target GINS4. In addition, circMLLT10 promoted cell growth and metastasis and suppressed cell apoptosis, whereas miR-509-3-5p inhibited cell growth and metastasis and promoted cell apoptosis.

Conclusion: The findings indicate for the first time that the novel GINS4 axis promotes gastric cancer cell growth and progression by activating Rac1 and CDC42. GINS4 may be a promising biomarker and target for diagnosis and treatment of gastric cancer.

LSH interacts with and stabilizes GINS4 transcript that promotes tumourigenesis in non-small cell lung cancer

Background

Elucidating mechanisms in oncogenes and epigenetic modifiers are needed to gain insights into the etiology and treatment of cancer, regulation of oncogene by chromatin modifiers at post-transcriptional level is critical and remains unclear. We have investigated the role of GINS4 in NSCLC.

Methods

The expression of chromatin modifier lymphoid-specific helicase (LSH) and GINS4 was assessed in tumor and normal tissue from 79 patients with NSCLC with clinical characteristics. HBE, A549, H358, and H522, PC9, 95C and 95D were cultured after overexpression or silencing of GIAT4RA. Cell proliferation assay, cell migration and invasion assays, plate colony formation assay, immunofluorescence assay, Operetta® high-content screening and analysis, Western blot analysis and Co-Immunoprecipitation (Co-IP) assay, RNA immunoprecipitation assay and tumor growth assay was used to address the potential interplay of between GINS4 and LSH, and the functional of GINS4.

Results

GINS4 is highly expressed in lung cancer cells and tissues, and GINS4 expression is not association with clinical risk factors, but linked with clinical stage and lymphatic metastasis status. Higher expression of GINS4 poorly linked with overall survival in lung adenocarcinomas. Furthermore, GINS4 promoted many characteristics of tumorigenesis including cell growth, clonal formation, migration and invasion, epithelial–mesenchymal transition, tumor sphere and tumor growth in vivo. Interestingly, our results demonstrated that LSH increases GINS4 expression through binding to 3’UTR region of GINS4 and stabilizing its mRNA levels. Finally, LSH overexpression rescues GINS4 knockdown-induced features.

Conclusions

GINS4 facilitates lung cancer progression by promoting key characteristics of tumor potential, and LSH epigenetically interacts with and stabilizes GINS4 transcripts.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1276-y) contains supplementary material, which is available to authorized users.

Embryonic expression of GINS members in the development of the mammalian nervous system

The GINS (Go, Ichi, Nii, and San) complex contains four protein subunits (PSF1, PSF2, PSF3, and SLD5) and has been identified as a factor essential for the initiation and elongation stages of the DNA replication process. A previous study indicated that PSF2 participated in the developing central nervous system (CNS) of Xenopus laevis. However, the expression and function of GINS members in the mammalian developing nervous system remains unclear. Here, we examined the expression of GINS members in mice during nervous system development via immunofluorescence staining. At the beginning of neural development, PSF1 and SLD5 were highly expressed in neuroepithelial stem cells (NSCs) of the inner surface of neural tube (NT) and overlapped with proliferation marker Ki67. After entering the mid- and late-phase of neural development, PSF1 and SLD5 changed their regions of expression. These genes were highly expressed in dorsal root ganglion (DRG) progenitors, but they showed no overlap with Ki67 positive cells. Instead, a reduction of SLD5 expression promoted neuronal differentiation and maturation in the late-phase. PSF2 and PSF3 showed no tissue-specificity. PSF2 was constitutively and highly expressed whereas PSF3 was expressed at very low levels during neural development. In this study, we demonstrated variations in proteins and expression regions of the GINS members during mammalian CNS development and revealed a correlation between GINS expression and cell proliferation. Furthermore, we have suggested a novel function of GINS member SLD5, which regulates the differentiation of neural stem/progenitors.

Influenza virus matrix protein M1 interacts with SLD5 to block host cell cycle

Influenza virus matrix 1 protein (M1) is highly conserved and plays essential roles at many stages of virus life cycle. Here, we used a yeast two-hybrid system to identify the host protein SLD5, a component of the GINS complex, which is essential for the initiation of DNA replication in eukaryotic cells, as a new M1 interacting protein. M1 from several different influenza virus strains all interacted with SLD5. Overexpression of SLD5 suppressed influenza virus replication. Transient, stable, or inducible expression of M1 induced host cell cycle blockade at G0/G1 phase. Moreover, SLD5 partially rescued M1 expression- or influenza virus infection-induced G0/G1 phase accumulation in cell lines and primary mouse embryonic fibroblasts. Importantly, SLD5 transgenic mice exhibited higher resistance and improved lung epithelial regeneration after virus infection compared with wild-type mice. Therefore, influenza virus M1 blocks host cell cycle process by interacting with SLD5. Our finding reveals the multifunctional nature of M1 and provides new insight for understanding influenza virus-host interaction.

Up-regulated and interrelated expressions of GINS subunits predict poor prognosis in hepatocellular carcinoma

The GINS complex is one of the core components of the eukaryotic replicative helicase CMG (Cdc45–MCM helicase–GINS) complex that serves as the replicative helicase unwinding duplex DNA ahead of moving replication fork during chromosome duplication. Many studies have highlighted the important functions amongst GINS subunits in various cancers. Nevertheless, the functions and prognostic roles of distinct GINS subunits in hepatocellular carcinoma (HCC) were largely unexplored. In the present study, we reported the prognostic values of GINS subunits in HCC patients through analysis of several databases, including Oncomine, (TCGA), and Kaplan–Meier Plotter (KMPlotter). We found that mRNA expressions of all GINS subunits were significantly up-regulated in HCC tumor than in non-tumor liver tissues. Survival analysis revealed that elevated expression of individual GINS subunit predicts a poor overall survival (OS) in all HCC patients. When sorting the patients by gender, the correlation between elevated expression of individual GINS subunit and poor OS remains significant in male patient subgroup, but not in female patient subgroup. Additionally, we found that co-overexpression of all GINS subunits was significantly associated with a higher hazard ratio, suggesting the GINS complex may co-operate to promote HCC progression. Indeed, their expressions were highly correlated with each other in the same cohort and TRANSFAC analysis revealed that four transcription factors including C/EBPα, Oct-1, Sp1, and USF may serve as common transcription factors binding to the promoters of all four GINS subunits. Therefore, we propose that individual GINS subunit or GINS complex as a whole could be potential prognostic biomarkers for HCC.

GINS2 promotes cell proliferation and inhibits cell apoptosis in thyroid cancer by regulating CITED2 and LOXL2

To explore the mechanisms of GINS2 on cell proliferation and apoptosis in thyroid cancer (TC) cells. Expressions of GINS2 were inhibited in K1 and SW579 cells using gene interference technology. The abilities of proliferation and apoptosis, and cell cycle were determined by MTT assay and flow cytometric assay. The downstream molecules of GINS2 were searched by microarray and bioinformatics and validated by qRT-PCR and western blotting. In the in vivo study, the tumor growth was compared and the whole-body fluorescent imaging was analyzed. After GINS2 was interfered, cell proliferation was significantly inhibited (P < 0.01) and apoptosis rate increased (P < 0.01) in both K1 and SW579 cells. Cell cycle changed significantly in K1 cells, but not in SW579 cells. With bioinformatics upstream analysis, TGF-β1 was found as the most significantly upstream regulator. Expressions of TGF-β1 and its downstream target molecules CITED2 and LOXL2 were validated and found downregulated significantly in mRNA and protein levels (P < 0.05). The results of the nude mouse xenograft assay suggested that the volume and weight of tumor in ones infected with shGINS2 were statistically smaller than controls (P < 0.05). GINS2 plays an important role in cell proliferation and apoptosis of thyroid cancer by regulating the expressions of CITED2 and LOXL2, which may be a potential biomarker for diagnosis or prognosis and a drug target for therapy.

The Human Replicative Helicase, the CMG Complex, as a Target for Anti-cancer Therapy

DNA helicases unwind or rearrange duplex DNA during replication, recombination and repair. Helicases of many pathogenic organisms such as viruses, bacteria, and protozoa have been studied as potential therapeutic targets to treat infectious diseases, and human DNA helicases as potential targets for anti-cancer therapy. DNA replication machineries perform essential tasks duplicating genome in every cell cycle, and one of the important functions of these machineries are played by DNA helicases. Replicative helicases are usually multi-subunit protein complexes, and the minimal complex active as eukaryotic replicative helicase is composed of 11 subunits, requiring a functional assembly of two subcomplexes and one protein. The hetero-hexameric MCM2-7 helicase is activated by forming a complex with Cdc45 and the hetero-tetrameric GINS complex; the Cdc45-Mcm2-7-GINS (CMG) complex. The CMG complex can be a potential target for a treatment of cancer and the feasibility of this replicative helicase as a therapeutic target has been tested recently. Several different strategies have been implemented and are under active investigations to interfere with helicase activity of the CMG complex. This review focuses on the molecular function of the CMG helicase during DNA replication and its relevance to cancers based on data published in the literature. In addition, current efforts made to identify small molecules inhibiting the CMG helicase to develop anti-cancer therapeutic strategies were summarized, with new perspectives to advance the discovery of the CMG-targeting drugs.

DNA Methylation Mediated Down-Regulation of miR-370 Regulates Cell Growth through Activation of the Wnt/β-Catenin Signaling Pathway in Human Osteosarcoma Cells

MicroRNA-370 (miR-370) has been observed to act as a tumor suppressor through the targeting of different proteins in a variety of tumors. Our previous study indicated that miR-370 was able to target forkhead box protein M1 (FOXM1) to inhibit cell growth and metastasis in human osteosarcoma cells. In this study, we reported that FOXM1 interacted with β-catenin in vitro and in vivo. Similar to FOXM1, critical components of the Wnt signaling pathway, including β-catenin, c-Myc, and Cyclin D1, were also highly expressed in different human osteosarcoma cells lines. Pharmacological inhibition of FOXM1 or β-catenin but not of c-Myc was associated with the increased expression of miR-370. Ectopic expression of miR-370 inhibited the downstream signaling of β-catenin. Moreover, osteosarcoma cells treated with 5-AZA-2'-deoxycytidine (AZA), a DNA methylation inhibitor, exhibited increased levels of miR-370 and decreased levels of β-catenin downstream targets, which resulted in inhibition of cell proliferation and colony formation ability. In conclusion, our results supported a model in which the DNA methylation-mediated down-regulation of miR-370 reduced its inhibitory effect on FOXM1, thereby promoting FOXM1-β-catenin interaction and activating the Wnt/β-Catenin signaling pathway in human osteosarcoma cells.

Amyloid β peptide promotes lysosomal degradation of clusterin via sortilin in hippocampal primary neurons

Progressive accumulation of amyloid-β peptide (Aβ) in the brain is implicated as the central event in the development of Alzheimer's disease (AD). It is thought that extracellular Aβ triggers toxic signals leading to neurodegeneration. The events downstream of Aβ however are not entirely clear. Clusterin (Apo J) is one of the major risk factors for sporadic form of AD. Clusterin binds to Aβ and prevents Aβ aggregation. In addition, clusterin promotes Aβ degradation and accelerates Aβ clearance from the brain. Clusterin thus protects neurons from Aβ and loss of clusterin level in the brain is implicated as promoting AD pathology. In this study, we found that the level of clusterin protein but not mRNA is reduced in the brains of 3xTg-AD mice. When rat hippocampal primary neurons were treated with Aβ1-42, level of clusterin protein but not mRNA was downregulated. Aβ1-42-induced downregulation of clusterin was blocked by lysosome inhibitors bafilomycin A1 and ammonium chloride. In neurons, Aβ1-42 induced expression of sortilin, a lysosomal sorting protein that targets proteins to lysosome for degradation. In BE(2) M17 human neuroblastoma cells, clusterin bound to sortilin and when sortilin expression was silenced, Aβ1-42-induced clusterin downregulation was almost completely blocked. Our data demonstrate that in neurons, Aβ1-42 promotes lysosomal degradation of clusterin by inducing expression of sortilin and provide a novel mechanism by which Aβ promotes AD pathogenesis.