MiR-126 negatively regulates PLK-4 to impact the development of hepatocellular carcinoma via ATR/CHEK1 pathway

MicroRNA-126 (MiR-126): key roles in related diseases

In eukaryotes such as humans, some non-coding single-stranded RNAs (ncRNAs) help to regulate the pre- and post-transcriptional expression of certain genes, which in turn control many important physiological processes, such as cell proliferation, distinctions, invasion, angiogenesis, and embryonic development. microRNA-126 is an important member of these miRNAs that can be directly or indirectly involved in the control of angiogenesis. Recently, numerous studies have expounded that microRNA-126 can inhibit or promote angiogenesis as well as attenuate inflammatory responses through complex molecular mechanisms. As such, it serves as a biomarker or potential therapeutic target for the prediction, diagnosis, and treatment of relevant diseases. In this review, we present the advancements in research regarding microRNA-126's role in the diagnosis and treatment of related diseases, aiming to provide innovative therapeutic options for the diagnosis and treatment of clinically relevant diseases.

The prognostic values and immune characteristics of polo-like kinases (PLKs) family: A pan-cancer multi-omics analysis

Background

In the realm of tumor-targeted therapeutics, Polo-like kinases (PLKs) are a significant group of protein kinases that were found recently as being related to tumors. However, the significance of PLKs in pan-cancer remains systematically studied.

Methods and materials

We integrated multi-omics data to comprehensively investigate the expression patterns of the PLK family across various cancer types. Subsequently, study examined the associations between tumor mutation burden (TMB), microsatellite instability (MSI), immune subtype classification, immune infiltration, tumor microenvironment scores, immune checkpoint gene expression, and the PLKs expression profiles within various tumor types. Furthermore, using our mRNA sequencing data (TRUCE01) and four bladder cancer (BLCA) cohorts (GSE111636, GSE176307, and IMvigor210), We examined the correlation between the expression level of PLK and immunotherapy effectiveness. Next, Gene set enrichment analysis (GSEA) was evaluated to find that potentially enriched PLK signaling pathways. Utilizing TIMER 2.0, we conducted an immune infiltration analysis underlying transcriptome expression, copy number variations (CNV), or somatic mutations of PLKs in BLCA. Finally, mRNA expression validation of PLK1/3/4 by real-time PCR within 10 paired BLCA tissues, protein expression verification through the Human Protein Atlas (HPA), and PLK4 in vitro cytological studies have been employed in BLCA.

Results

The expression of most of the PLK family members exhibits variation between cancerous tissues and adjacent normal tissues across various cancer species. Furthermore, the expression of PLKs demonstrates a significant association with immunotyping, infiltration of immune cell, tumor mutational burden (TMB), microsatellite instability (MSI), immunological checkpoint gene activity and therapeutic effectiveness in pan-tumor tissues. Additional investigation into the correlation between the PLK family and BLCA has revealed that the expression of the PLK genes holds substantial significance in the biological processes of BLCA. Furthermore, a notable association has been observed between the copy number variation, variant status, and the degree of certain immunological cell infiltration. Of note, the expression validation and in vitro phenotypic experiments have demonstrated that PLK4 has a significant function in promoting the BLCA cell proliferation, migration, and invasion.

Conclusion

Collectively, based on various databases, our results highlight the involvement of PLK gene family in the formation of different types of tumors and identify PLK-related genes that may be used for therapy.

PLK4 reflects extrathyroidal invasion, high tumor stage and poor prognosis in papillary thyroid carcinoma patients

Objective: This study aimed to assess the value of PLK4 as a biomarker in papillary thyroid carcinoma (PTC). Methods: This study reviewed 230 PTC patients receiving surgical resections. PLK4 was detected in tumor tissues and samples of normal thyroid gland tissues by immunohistochemistry. Results: PLK4 was elevated in tumor tissues versus normal thyroid gland tissues (p < 0.001). Tumor PLK4 was linked with extrathyroidal invasion (p = 0.036), higher pathological tumor stage (p = 0.030), node stage (p = 0.045) and tumor/node/metastasis stage (p = 0.022) in PTC patients. Tumor PLK4 immunohistochemistry score >3 was linked with shortened disease-free survival (p = 0.026) and overall survival (p = 0.028) and independently predicted poorer disease-free survival (hazard ratio: 2.797; p = 0.040). Conclusion: Tumor PLK4 reflects extrathyroidal invasion, higher tumor stage and shortened survival in PTC.

Therapeutic restoration of miR-126-3p as a multi-targeted strategy to modulate the liver tumor microenvironment

BACKGROUND

Impaired natural killer (NK) cell-mediated antitumor responses contribute to the growth of liver tumors. Expression of a disintegrin and metalloprotease 9 (ADAM9) increases shedding of membrane-bound major histocompatibility complex class I chain-related protein A and results in evasion from NK cell-mediated cytolysis. ADAM9 is also involved in angiogenesis and tumor progression and is a target of miR-126-3p, a tumor suppressor that is downregulated and alters tumor cell behavior in the liver and other cancers. We evaluated the restoration of miR-126-3p and modulation of the miR-126-3p/ADAM9 axis as a therapeutic approach to simultaneously enhance NK cell-mediated cytolysis while targeting both tumor cells and their microenvironment.

METHODS

Precursor miRNAs were loaded into milk-derived nanovesicles to generate therapeutic vesicles (therapeutic milk-derived nanovesicles) for the restoration of functional miR-126-3p in recipient cancer cells.

RESULTS

Administration of therapeutic milk-derived nanovesicles increased miR-126-3p expression and reduced ADAM9 expression in target cells and was associated with an increase in membrane-bound major histocompatibility complex class I chain-related protein A. This enhanced NK cell cytolysis in adherent tumor cells and in multicellular tumor spheroids while also impairing angiogenesis and modulating macrophage chemotaxis. Moreover, IV administration of therapeutic milk-derived nanovesicles with adoptive transfer of NK cells reduced tumor burden in orthotopic hepatocellular cancer xenografts in mice.

CONCLUSION

A directed RNA therapeutic approach can mitigate NK cell immune evasion, reduce angiogenesis, and alter the tumor cell phenotype through the restoration of miR-126-3p in liver tumor cells. The pleiotropic effects elicited by this multi-targeted approach to modulate the local tumor microenvironment support its use for the treatment of liver cancer.

Therapeutic potential of targeting polo-like kinase 4

Polo-like kinase 4 (PLK4), a highly conserved serine/threonine kinase, masterfully regulates centriole duplication in a spatiotemporal manner to ensure the fidelity of centrosome duplication and proper mitosis. Abnormal expression of PLK4 contributes to genomic instability and associates with a poor prognosis in cancer. Inhibition of PLK4 is demonstrated to exhibit significant efficacy against various types of human cancers, further highlighting its potential as a promising therapeutic target for cancer treatment. As such, numerous small-molecule inhibitors with distinct chemical scaffolds targeting PLK4 have been extensively investigated for the treatment of different human cancers, with several undergoing clinical evaluation (e.g., CFI-400945). Here, we review the structure, distribution, and biological functions of PLK4, encapsulate its intricate regulatory mechanisms of expression, and highlighting its multifaceted roles in cancer development and metastasis. Moreover, the recent advancements of PLK4 inhibitors in patent or literature are summarized, and their therapeutic potential as monotherapies or combination therapies with other anticancer agents are also discussed.

Centrosome amplification-related signature correlated with immune microenvironment and treatment response predicts prognosis and improves diagnosis of hepatocellular carcinoma by integrating machine learning and single-cell analyses

BACKGROUND

Centrosome amplification is a well-recognized oncogenic driver of tumor initiation and progression across a variety of malignancies and has been linked with tumor aggressiveness, metastasis, and adverse prognosis. Nevertheless, the significance of centrosome amplification in HCC is not well understood.

METHODS

The TCGA dataset was downloaded for centrosome amplification-related signature construction using the LASSO-penalized Cox regression algorithm, while the ICGC dataset was obtained for signature validation. Single-cell RNA sequencing from GSE149614 was analyzed to profile gene expression and the liver tumor niche.

RESULTS

A total of 134 centrosome amplification-related prognostic genes in HCC were detected and 6 key prognostic genes (SSX2IP, SPAG4, SAC3D1, NPM1, CSNK1D, and CEP55) among them were screened out to construct a signature with both high sensitivity and specificity in diagnosis and prognosis of HCC patients. The signature, as an independent factor, was associated with frequent recurrences, high mortality rates, advanced clinicopathologic features, and high vascular invasions. Moreover, the signature was intimately associated with cell cycle-related pathways and TP53 mutation profile, suggesting its underlying role in accelerating cell cycle progression and leading to liver cancer development. Meanwhile, the signature was also closely correlated with immunosuppressive cell infiltration and immune checkpoint expression, making it a vital immunosuppressive factor in the tumor microenvironment. Upon single-cell RNA sequencing, SSX2IP and SAC3D1 were found to be specially expressed in liver cancer stem-like cells, where they promoted cell cycle progression and hypoxia.

CONCLUSIONS

This study provided a direct molecular link of centrosome amplification with clinical characteristics, tumor microenvironment, and clinical drug-response, highlighting the critical role of centrosome amplification in liver cancer development and therapy resistance, thereby providing valuable insights into prognostic prediction and therapeutic response of HCC.

Inhibition of PLK4 remodels histone methylation and activates the immune response via the cGAS-STING pathway in TP53-mutated AML

Acute myeloid leukemia (AML) with TP53 mutation is one of the most lethal cancers and portends an extremely poor prognosis. Based on in silico analyses of druggable genes and differential gene expression in TP53-mutated AML, we identified pololike kinase 4 (PLK4) as a novel therapeutic target and examined its expression, regulation, pathogenetic mechanisms, and therapeutic potential in TP53-mutated AML. PLK4 expression was suppressed by activated p53 signaling in TP53 wild-type AML and was increased in TP53-mutated AML cell lines and primary samples. Short-term PLK4 inhibition induced DNA damage and apoptosis in TP53 wild-type AML. Prolonged PLK4 inhibition suppressed the growth of TP53-mutated AML and was associated with DNA damage, apoptosis, senescence, polyploidy, and defective cytokinesis. A hitherto undescribed PLK4/PRMT5/EZH2/H3K27me3 axis was demonstrated in both TP53 wild-type and mutated AML, resulting in histone modification through PLK4-induced PRMT5 phosphorylation. In TP53-mutated AML, combined effects of histone modification and polyploidy activated the cGAS-STING pathway, leading to secretion of cytokines and chemokines and activation of macrophages and T cells upon coculture with AML cells. In vivo, PLK4 inhibition also induced cytokine and chemokine expression in mouse recipients, and its combination with anti-CD47 antibody, which inhibited the "don't-eat-me" signal in macrophages, synergistically reduced leukemic burden and prolonged animal survival. The study shed important light on the pathogenetic role of PLK4 and might lead to novel therapeutic strategies in TP53-mutated AML.

The role of microRNAs in hepatocellular carcinoma: Therapeutic targeting of tumor suppressor and oncogenic genes

Hepatocellular carcinoma (HCC) is a severe malignant liver cancer with a poor prognosis and a high mortality rate. This carcinoma is a multistage process that begins with chronic hepatitis and progresses to cirrhosis, dysplastic nodules, and eventually HCC. However, the exact molecular etiology remains unclear. MicroRNAs (miRs) are small non-coding RNAs that modulate the expression of numerous genes. These molecules have become significant participants in several functions, including cell proliferation, differentiation, development, and tumorrelated properties. They have a pivotal role in carcinogenesis as oncogenes or tumor suppressor genes. Furthermore, some investigations have shown that particular miRs might be used as predictive or diagnostic markers and therapeutic targets in HCC therapy. This review study summarizes the current level of knowledge on the role of miRs in the initiation and progression of HCC.

miR-126 regulates the proliferation, migration, invasion, and apoptosis of non-small lung cancer cells via AKT2/HK2 axis

This study tended to clarify the role of miR-126 in non-small cell lung cancer (NSCLC) cell biological behaviors in vitro, containing cell proliferation, migration, invasion, and apoptosis. miRNA expression microarray related to NSCLC was accessed from gene expression omnibus (GEO) database and subjected to differential analysis using the "limma" package. Real-time quantitative PCR was conducted to assess the expression of miR-126 in NSCLC cell lines. wIn vitro experiments including 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), wound healing assay, Transwell, and flow cytometry assay were used for evaluating the effect of miR-126 on cell proliferation, migration, invasion, and apoptosis. Additionally, target mRNA for miR-126 was predicted and further validated by bioinformatics analysis and dual-luciferase reporter assay, respectively. It suggested that miR-126 was significantly down-regulated in NSCLS based on the expression microarray, and similar expression trend was exhibited in cancer cell lines. In the meantime, overexpression of miR-126 was found to result in inhibition of cell proliferation, migration, and invasion while promotion of cell apoptosis, with reductions in protein expression of AKT2 and phosphorylated HK2 (p-HK2) as well. AKT2, identified to be a direct target of miR-126 in NSCLC as judged by dual-luciferase reporter assay. Additionally, overexpression of AKT2 was observed to have the ability of elevating p-HK2 protein expression and reversing the effect of miR-126 on NSCLC cell proliferation, migration, and invasion. Given the above findings, we can see that miR-126 exerts its role in NSCLC cell proliferation, migration, invasion, and apoptosis with the aid of AKT2/HK2 axis.

Expressional and functional characteristics of checkpoint kinase 1 as a prognostic biomarker in hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is the most common pathological subtype of liver cancer and is the third leading cause of cancer death worldwide. Checkpoint kinase 1 (CHEK1), an essential serine/threonine kinase that regulates the cell cycle, is reported to be associated with carcinogenesis. However, the biological role and clinical significance of CHEK1 in HCC are still incompletely known.

Methods

In this research, CHEK1 messenger RNA (mRNA) levels in various liver hepatocellular carcinoma (LIHC) cohorts from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were evaluated. The Kaplan-Meier database was applied to identify the correlation between survival time and CHEK1 expression in patients with HCC. Gene set enrichment analysis (GSEA) was performed to explore the potential mechanism of CHEK1 in HCC, and NetworkAnalyst v. 3.0 (https://www.networkanalyst.ca/) was used to construct the regulatory networks of CHEK1 in HCC. Discriminant Regulon Expression Analysis (DoRothEA) was used to detect the activity of transcriptional factors (TFs) in gene-enriched cells (EC) with CHEK1 coexpression. In vitro experiments were conducted to investigate the effects of CHEK1 on the biological function of HCC cells.

Results

The CHEK1 mRNA level was overexpressed in HCC, and increased CHEK1 expression correlated with poor survival outcomes. The homo sapiens-microRNA-195 (hsa-miR-195) may have contributed to the upregulation of CHEK1 in HCC. GSEA and NetworkAnalyst v. 3.0 showed that CHEK1 played a crucial part in tumor proliferation of HCC and may be regulated by TF E2F1. DoRothEA showed increased transcriptional activity of E2F1 in gene-EC with CHEK1 coexpression. Moreover, experiments of cell function showed that the knockdown of CHEK1 weakened the aggressive behavior and proliferation of HCC cells. Overexpression of E2F1 increased the proliferation and invasion of HCC cells in vitro, while the silencing of CHEK1 dampened cell invasion induced by E2F1 overexpression.

Conclusions

These results identified the prognostic significance and expression characteristics of CHEK1 in HCC through bioinformatics analysis and experimental verification. This lays the foundation for further research on the diagnosis and treatment of HCC.

Upstream open reading frames control PLK4 translation and centriole duplication in primordial germ cells

Centrosomes are microtubule-organizing centers comprised of a pair of centrioles and the surrounding pericentriolar material. Abnormalities in centriole number are associated with cell division errors and can contribute to diseases such as cancer. Centriole duplication is limited to once per cell cycle and is controlled by the dosage-sensitive Polo-like kinase 4 (PLK4). Here, we show that PLK4 abundance is translationally controlled through conserved upstream open reading frames (uORFs) in the 5' UTR of the mRNA. Plk4 uORFs suppress Plk4 translation and prevent excess protein synthesis. Mice with homozygous knockout of Plk4 uORFs (Plk4 Δu/Δu ) are viable but display dramatically reduced fertility because of a significant depletion of primordial germ cells (PGCs). The remaining PGCs in Plk4 Δu/Δu mice contain extra centrioles and display evidence of increased mitotic errors. PGCs undergo hypertranscription and have substantially more Plk4 mRNA than somatic cells. Reducing Plk4 mRNA levels in mice lacking Plk4 uORFs restored PGC numbers and fully rescued fertility. Together, our data uncover a specific requirement for uORF-dependent control of PLK4 translation in counterbalancing the increased Plk4 transcription in PGCs. Thus, uORF-mediated translational suppression of PLK4 has a critical role in preventing centriole amplification and preserving the genomic integrity of future gametes.

CBX3 regulated by miR-139 promotes the development of HCC by regulating cell cycle progression

Hepatocellular carcinoma (HCC), a major primary liver cancer, is one of the most lethal malignancies worldwide. Increasing evidence has demonstrated that chromobox protein homolog 3 (CBX3) functions as an oncogene in different cancers. However, its expression profiles and biological functions in HCC remain unknown. Data on CBX3 expression in HCC acquired from the GEO and TCGA databases were analyzed. The biological functions of CBX3 in HCC were examined by in vitro experiments. Bioinformatics analysis, qRT-PCR and western blotting were performed to explore the mechanism of CBX3 in HCC. CBX3 mRNA was upregulated in HCC tissues, and overexpression of CBX3 mRNA was negatively correlated with malignancies and poor prognosis in HCC patients. CBX3 knockdown decreased growth, migration and invasion of HCC cells in vitro. Moreover, bioinformatics analysis and experimental observation indicated that CBX3 expression was correlated with cell cycle regulatory proteins in HCC cells. Finally, starBase predicted that miR-139 could directly target CBX3 in HCC. Confirmatory experiments verified that miR-139 overexpression attenuated HCC cell proliferation and migration, and these effects could be reversed by overexpressing CBX3. Our results showed that the miR-139/CBX3 axis may be involved in HCC development by regulating cell cycle progression and may be a promising target in the treatment of HCC.

MiR-126 downregulates CXCL12 expression in intestinal epithelial cells to suppress the recruitment and function of macrophages and tumorigenesis in a murine model of colitis-associated colorectal cancer

Inflammatory bowel disease, characterised by chronic relapsing‐remitting colitis, is a significant risk factor for colorectal cancer (CRC). Previously, we showed that miR‐126 functions as a tumour suppressor in CRC and is inversely correlated with tumour proliferation, metastasis and patient prognosis. In the current study, we documented a protective role for miR‐126 in colitis‐associated CRC (CAC) and its underlying mechanism. We detected downregulated miR‐126 expression during colorectal tumorigenesis in the mouse CAC model and in specimens from patients with CRC. The deficiency of miR‐126 in intestinal epithelial cells (IECs) exacerbated tumorigenesis in mice. We identified CXCL12 as a direct target of miR‐126 in inhibiting the development of colitis and CAC. Moreover, miR‐126 regulated the recruitment of macrophages via CXCL12 and decreased the levels of proinflammatory cytokines (IL‐6, IL‐12 and IL‐23). In addition, IL‐6 secreted by macrophages, which were regulated by cocultured transfected CRC cells, altered the proliferation and migration of colon cells. Our data suggest that miR‐126 exerts an antitumour effect on CAC by regulating the crosstalk between IECs and macrophages via CXCL12‐IL‐6 signalling. Our study contributes to the understanding of cancer progression and suggests miR‐126 as a potential therapy for CRC.

Identification of a Novel Survival-Related circRNA–miRNA–mRNA Regulatory Network Related to Immune Infiltration in Liver Hepatocellular Carcinoma

Increasing studies have reported that circular RNAs (circRNAs) play critical roles in tumorigenesis and cancer progression. However, the underlying regulatory mechanisms of circRNA-related competing endogenous RNA (ceRNA) in liver hepatocellular carcinoma (LIHC) are still unclear. In the present study, we discovered dysregulated circRNAs through Gene Expression Omnibus (GEO) analysis and validated the expression of the top seven circRNAs with upregulated expression by qRT–PCR and Sanger sequencing. Then, the Cancer-Specific CircRNA Database (CSCD) was used to predict the downstream miRNAs of seven circRNAs, and expression and survival analyses through The Cancer Genome Atlas (TCGA) were performed to identify the key miRNA in LIHC. Thereafter, the hsa_circ_0017264-hsa-miR-195–5p subnetwork was successfully constructed. Subsequently, we predicted downstream target genes of hsa-miR-195–5p with TargetScan, miRDB, and mirtarbase and overlapped them with differentially expressed mRNAs to obtain 21 target genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to predict the biological and functional roles of these target genes. Finally, with Pearson correlation and prognostic value analysis, a survival-related hsa_circ_0017264-hsa-miR-195-5p-CHEK1/CDC25A/FOXK1 axis was established. Gene set enrichment analysis (GSEA) was performed to determine the function of CHEK1/CDC25A/FOXK1 in the ceRNA network. Moreover, immune infiltration analysis revealed that the ceRNA network was markedly associated with the levels of multiple immune cell infiltrates, immune cell biomarkers and immune checkpoints. Overall, the hsa_circ_0017264-hsa-miR-195-5p-CHEK1/CDC25A/FOXK1 network might provide novel insights into the potential mechanisms underlying LIHC onset and progression.

MiR-139-3p Targets CHEK1 Modulating DNA Repair and Cell Viability in Lung Squamous Carcinoma Cells

Non-small-cell lung carcinoma (NSCLC) can be classified into several subtypes, where lung squamous carcinoma (LUSC) is one common subtype. Though miR-139-3p has been reported to be implicated in the development of various cancers, its mechanisms and functions remain unclear in LUSC. In this study, miR-139-3p was screened as one of the significantly down-regulated miRNAs in LUSC by an "edgeR" differential analysis based on TCGA database, which was verified by qRT-PCR in LUSC cell lines as well. The viability and cell cycle of the LUSC cells were examined by CCK-8 and flow cytometry, respectively, exhibiting that upregulating miR-139-3p restrained cell viability and thus accelerating the cell cycle. To explain this phenomenon, we further explored the downstream target gene through miRTarBase and starBase databases, where CHEK1 was predicted as one candidate. The targeting relationship was verified by a dual luciferase assay, identifying that CHEK1 could be targeted by miR-139-3p. Then, qRT-PCR and western blot analyses were performed to detect the expression of CHEK1 mRNA and proteins under the alteration of miR-139-3p expression. Rescue experiments were conducted to confirm the impacts of miR-139-3p/CHEK1 axis on the cell viability and cell cycle of LUSC. The results indicated that the effects of miR-139-3p on the LUSC cell phenotypes could be blocked by overexpressing CHEK1. In conclusion, our study provides a novel insight into the regulatory role of miR-139-3p in the development of LUSC.

TEC kinase stabilizes PLK4 to promote liver cancer metastasis

Aberrated PLK4 expression has been reported in different malignancies and causes centrosome amplification, aneuploidy, and genomic instability. However, the mechanism by which PLK4 is regulated in carcinogenesis remains not fully characterised. Here, we showed that PLK4 was overexpressed in human HCC and overexpression of PLK4 predicted poorer patient prognosis. Unexpectedly, we found that induced expression of PLK4 promotes, but knockdown of PLK4 inhibits, HCC cell migration and invasion. Mechanistically, we found that TEC tyrosine kinase, which also promotes HCC cell migration, stabilizes PLK4 by phosphorylation. TEC directly phosphorylates PLK4 at tyrosine 86 residue, which not only stabilizes the protein but also enhances PLK4-mediated HCC cell invasion. Further investigation by transcriptome sequencing indicated that PLK4 promotes the phosphorylation of focal adhesion kinase to regulate the focal adhesion pathway in HCC cell migration. Taken together, our results demonstrated that PLK4 plays an important role in HCC metastasis and revealed for the first time the mechanism by which PLK4 promotes HCC metastasis via TEC phosphorylation.

Downregulation of METTL6 mitigates cell progression, migration, invasion and adhesion in hepatocellular carcinoma by inhibiting cell adhesion molecules

RNA modifications have attracted increasing interest in recent years because they have been frequently implicated in various human diseases, including cancer, highlighting the importance of dynamic post‑transcriptional modifications. Methyltransferase‑like 6 (METTL6) is a member of the RNA methyltransferase family that has been identified in many cancers; however, little is known about its specific role or mechanism of action. In the present study, we aimed to study the expression levels and functional role of METTL6 in hepatocellular carcinoma (HCC), and further investigate the relevant pathways. To this end, we systematically conducted bioinformatics analysis of METTL6 in HCC using gene expression data and clinical information from a publicly available dataset. The mRNA expression levels of METTL6 were significantly upregulated in HCC tumor tissues compared to that in adjacent non‑tumor tissues and strongly associated with poorer survival outcomes in patients with HCC. CRISPR/Cas9‑mediated knockout of METTL6 in HCC cell lines remarkably inhibited colony formation, cell proliferation, cell migration, cell invasion and cell attachment ability. RNA sequencing analysis demonstrated that knockout of METTL6 significantly suppressed the expression of cell adhesion‑related genes. However, chromatin immunoprecipitation sequencing results revealed no significant differences in enhancer activities between cells, which suggests that METTL6 may regulate genes of interest post‑transcriptionally. In addition, it was demonstrated for the first time that METTL6 was localized in the cytosol as detected by immunofluorescence analysis, which indicates the plausible location of RNA modification mediated by METTL6. Our findings provide further insight into the function of RNA modifications in cancer and suggest a possible role of METTL6 as a therapeutic target in HCC.

MicroRNAs and the DNA damage response: How is cell fate determined?

It is becoming clear that the DNA damage response orchestrates an appropriate response to a given level of DNA damage, whether that is cell cycle arrest and repair, senescence or apoptosis. It is plausible that the alternative regulation of the DNA damage response (DDR) plays a role in deciding cell fate following damage. MicroRNAs (miRNAs) are associated with the transcriptional regulation of many cellular processes. They have diverse functions, affecting, presumably, all aspects of cell biology. Many have been shown to be DNA damage inducible and it is conceivable that miRNA species play a role in deciding cell fate following DNA damage by regulating the expression and activation of key DDR proteins. From a clinical perspective, miRNAs are attractive targets to improve cancer patient outcomes to DNA-damaging chemotherapy. However, cancer tissue is known to be, or to become, well adapted to DNA damage as a means of inducing chemoresistance. This frequently results from an altered DDR, possibly owing to miRNA dysregulation. Though many studies provide an overview of miRNAs that are dysregulated within cancerous tissues, a tangible, functional association is often lacking. While miRNAs are well-documented in 'ectopic biology', the physiological significance of endogenous miRNAs in the context of the DDR requires clarification. This review discusses miRNAs of biological relevance and their role in DNA damage response by potentially 'fine-tuning' the DDR towards a particular cell fate in response to DNA damage. MiRNAs are thus potential therapeutic targets/strategies to limit chemoresistance, or improve chemotherapeutic efficacy.

Hub Genes and Key Pathways of Intervertebral Disc Degeneration: Bioinformatics Analysis and Validation

Objective

To identify significant pathways and genes in intervertebral disc degeneration (IDD) based on bioinformatics analysis.

Design

The GEO database was used to download the GSE124272 dataset. Differentially expressed genes (DEGs) were analyzed using Limma package in R language. Then, gene ontologies (GO), Kyoto encyclopedia of genes and genomes (KEGG), and protein-protein interaction (PPI) networks were used to further identify hub genes. The mRNA expression levels of top six hub genes were verified.

Results

We found 563 DEGs, of which 214 were upregulated and 349 were downregulated. The top 5 GO terms and pathways were shown including immune response, cell cycle, and p53 pathway. Based on the PPI analysis, we verified the mRNA expression levels of 6 hub genes. The mRNA levels of CHEK1, CDCA2, SKA3, and KIF20A were upregulated in degenerative NP tissue than in healthy NP tissue. However, the mRNA level of BUB1 and SPC25 was downregulated.

Conclusions

This study may provide new biomarkers for the IDD and treatments to repair IDD related to CHEK1, CDCA2, SKA3, BUB1, KIF20A, and SPC25.

miR-199a-5p inhibits the proliferation of hepatocellular carcinoma cells by regulating CDC25A to induce cell cycle arrest

BACKGROUND

Hepatocellular carcinoma (HCC) has been verified as a really common cancer worldwide. Several studies have suggested that the suppression of malignancy growth can be traced to miR-199a-5p. Even though CDC25A could activate the tumorigenesis of various cancer by modulating cell cycle, the modulation of the miR-199a-5p/CDC25A axis is still not clear in HCC. Our aim is to identify the modulation of the miR-199a-5p/CDC25A axis in HCC.

METHODS

The expression of CDC25A and miR-199a-5p in HCC cells and tissues was assessed using qRT-PCR. After using western blot assay to confirm the protein level, luciferase reporter and RNA pull-down assays were performed to explore the relation between CDC25A and miR-199a-5p. Functional assays such as CCK8 assay, BrdU proliferation assay and flow cytometry analysis identified the cell progression.

RESULTS

Experimental findings indicated the downregulation of miR-199a-5p in HCC samples. It was also found that miR-199a-5p overexpression declined the development of the cells with HCC and that it could bind to CDC25A to suppress the progression of HCC.

CONCLUSION

Research suggested that miR-199a-5p could restrain the proliferation ability of HCC cells by regulating CDC25A, thus inducing cell-cycle arrest.

The mechanisms of renin-angiotensin system in hepatocellular carcinoma: From the perspective of liver fibrosis, HCC cell proliferation, metastasis and angiogenesis, and corresponding protection measures

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, of which the occurrence and development involve a variety of pathophysiological processes, such as liver fibrosis, hepatocellular malignant proliferation, metastasis, and tumor angiogenesis. Some important cytokines, such as TGF-β, PI3K, protein kinase B (Akt), VEGF and NF-κB, can regulate the growth, proliferation, diffusion, metastasis, and apoptosis of HCC cells by acting on the corresponding signaling pathways. Besides, many studies have shown that the formation of HCC is closely related to the main components of renin-angiotensin system (RAS), such as Ang II, ACE, ACE2, MasR, AT1R, and AT2R. Therefore, this review focused on liver fibrosis, HCC cell proliferation, metastasis, tumor angiogenesis, and corresponding protective measures. ACE-Ang II-AT1 axis and ACE2-Ang-(1-7)-MasR axis were taken as the main lines to introduce the mechanism of RAS in the occurrence and development of HCC, so as to provide references for future clinical work and scientific research.

AURKB, CHEK1 and NEK2 as the Potential Target Proteins of Scutellaria barbata on Hepatocellular Carcinoma: An Integrated Bioinformatics Analysis

Objective

We aim to explore the potential anti-HCC mechanism of Scutellaria barbata through integrated bioinformatics analysis.

Methods

We searched active ingredients and related targets of Scutellaria barbata via TCMSP database, PubChem and SwissTargetPrediction database. Then, we identified HCC disease targets from GEO dataset by WGCNA. Next, the intersected targets of disease targets and drug targets were input into STRING database to construct PPI networking in order to obtain potential therapeutic targets of Scutellaria barbata. Cytoscape software was used to carry out network topology analysis of potential targets. We used the R package for GO analysis and KEGG analysis. Finally, we used AutoDock vina and PyMOL software for molecular docking.

Results

Sixteen active components from Scutellaria barbata were lastly selected for further investigation. A total of 442 component targets were identified from 16 active ingredients of Scutellaria barbata after the removal of duplicate targets. GSE45436 was selected for construction of WGCNA and screening of differentially expressed genes. A total of 354 genes were up-regulated in HCC samples and 100 were down-regulated in HCC patients. Twenty-one common genes were obtained by intersection and 10 critical targets were filtered for further investigation. The enrichment analysis showed that cell cycle, DNA replication, p53 signaling pathway were mainly involved. The molecular docking results showed that 4 potential combinations were with the best binding energy and molecular interactions.

Conclusion

AURKB, CHEK1 and NEK2 could be the potential target proteins of Scutellaria barbata in treating HCC. Cell cycle, DNA replication, p53 signaling pathway consist of the fundamental regulation cores in this mechanism.

Identification and assessment of PLK1/2/3/4 in lung adenocarcinoma and lung squamous cell carcinoma: Evidence from methylation profile

Lung cancer is a very aggressive cancer characterized with molecular heterogeneities in different subtypes, including lung adenocarcinoma and lung squamous cell carcinoma. However, few related molecular signatures have been established for the treatment of lung cancer subtypes. Polo-like kinase (PLK) family is a crucial regulator during cell division. Aberrant genetic and epigenetic alteration of PLK members plays a controversial role among different cancers. In this study, we performed an analysis of transcriptional and protein expression to identify overexpressed PLK1/4 and under-expressed PLK2/3 in lung cancer subtypes. We then analysed biological function of PLKs and related genes. Besides, we estimated a correlation of PLKs with patient's genders and TP53 mutation in lung cancer. Higher PLK1/4 expression was significantly associated with male patient and TP53 mutant status, separately. Moreover, we carried out a methylation profile analysis including methylation level, DNA methyltransferases correlation and survival analysis of global methylation. Global methylation survival analysis showed that prognostic value of PLK1/2/4 methylation remained the same significant trend between two lung cancer subtypes, whereas prognostic value of PLK3 methylation lacked consistency. Taken together, these results provided instructive insights into a comprehensive evaluation for advanced therapeutic strategy based on epigenetic evidences.

Preparation, Synergism, and Biocompatibility of in situ Liquid Crystals Loaded with Sinomenine and 5-Fluorouracil for Treatment of Liver Cancer

PURPOSE

Transarterial chemoembolization is the preferred treatment for patients with middle and advanced-stage hepatocellular carcinoma (HCC); however, most hepatic artery embolization agents have various disadvantages. The purpose of this study was to evaluate phytantriol-based liquid crystal injections for potential use in treatment of HCC.

METHODS

Using sinomenine (SN) and 5-fluorouracil (5-FU) as model drugs, three precursor in situ liquid crystal injections based on phytantriol (P1, P2, and P3) were prepared, and their in vitro biocompatibility, anticancer activity, and drug release investigated, to evaluate their feasibility for use in treatment of HCC. The properties of the precursor injections and subsequent cubic liquid crystal gels were observed by visual and polarizing microscopy, in an in vitro gelation experiment. Biocompatibility was evaluated by in vitro hemolysis, histocompatibility, and cytotoxicity assays.

RESULTS

Precursor injections were colorless liquids that formed transparent cubic liquid crystal gels on addition of excess water. The three precursor injections all caused slight hemolysis, without agglutination, and were mildly cytotoxic. Histocompatibility experiments showed that P1 had good histocompatibility, while P2 and P3 resulted in strong inflammatory responses, which subsequently resolved spontaneously. In vitro anti-cancer testing showed that SN and 5-FU inhibited HepG2 cells in a time- and concentration-dependent manner and had synergistic effects. Further, in vitro release assays indicated that all three preparations had sustained release effects, with cumulative release of >80% within 48 h.

CONCLUSION

These results indicate that SN and 5-FU have synergistic inhibitory effects on HepG2 cells, which has not previously been reported. Moreover, we describe a biocompatible precursor injection, useful as a drug carrier for the treatment of liver cancer, which can achieve targeting, sustained release, synergistic chemotherapy, and embolization. These data indicate that precursor injections containing SN and 5-FU have great potential for use in therapy for liver cancer.

Current Implications of microRNAs in Genome Stability and Stress Responses of Ovarian Cancer

Genomic alterations and aberrant DNA damage signaling are hallmarks of ovarian cancer (OC), the leading cause of mortality among gynecological cancers worldwide. Owing to the lack of specific symptoms and late-stage diagnosis, survival chances of patients are significantly reduced. Poly (ADP-ribose) polymerase (PARP) inhibitors and replication stress response inhibitors present attractive therapeutic strategies for OC. Recent research has focused on ovarian cancer-associated microRNAs (miRNAs) that play significant regulatory roles in various cellular processes. While miRNAs have been shown to participate in regulation of tumorigenesis and drug responses through modulating the DNA damage response (DDR), little is known about their potential influence on sensitivity to chemotherapy. The main objective of this review is to summarize recent findings on the utility of miRNAs as cancer biomarkers, in particular, ovarian cancer, and their regulation of DDR or modified replication stress response proteins. We further discuss the suppressive and promotional effects of various miRNAs on ovarian cancer and their participation in cell cycle disturbance, response to DNA damage, and therapeutic functions in multiple cancer types, with particular focus on ovarian cancer. Improved understanding of the mechanisms by which miRNAs regulate drug resistance should facilitate the development of effective combination therapies for ovarian cancer.

miR-378c suppresses Wilms tumor development via negatively regulating CAMKK2

Wilms tumor is a rare kidney malignancy primarily developed in children. Treatment for Wilms tumor includes surgery, radiotherapy, and chemotherapy. Recent studies have demonstrated that microRNAs (miRNAs) play important roles in regulating Wilms tumor development. In this study, we aimed to elucidate the expression and function of miR-378c in Wilms tumor. Quantitative real-time PCR (qRT-PCR) results showed that miR-378c was downregulated in Wilms tumor tissues and cell lines. Functionally, further CCK-8, would healing, and transwell assays revealed that overexpression of miR-378c impaired Wilms tumor cell growth and metastasis in vitro. In addition, xenograft assay showed that miR-378c overexpression inhibited Wilms tumor development in vivo. Mechanistically, luciferase reporter assay confirmed that miR-378c directly targets CAMKK2 in Wilms tumor. qRT-PCR and western blot assays demonstrated that CAMKK2 was highly expressed in Wilms tumor tissues and cell lines. Rescue experiments were performed to further evaluate the functional relationship between miR-378c and CAMKK2. Overexpression of miR-378c suppressed Wilms tumor cell metastasis via negatively regulating CAMKK2 expression. Consistently, inhibition of miR-378c enhanced Wilms tumor cell malignancy behavior via augmenting CAMKK2 expression, which could be abrogated by CAMKK2 knockdown. In summary, our findings suggest that miR-378c inhibits the development and metastasis of Wilms tumor via negatively regulating CAMKK2 expression, which could be utilized to develop new therapy strategy.

Modelling the Functions of Polo-Like Kinases in Mice and Their Applications as Cancer Targets with a Special Focus on Ovarian Cancer

Polo-like kinases (PLKs) belong to a five-membered family of highly conserved serine/threonine kinases (PLK1-5) that play differentiated and essential roles as key mitotic kinases and cell cycle regulators and with this in proliferation and cellular growth. Besides, evidence is accumulating for complex and vital non-mitotic functions of PLKs. Dysregulation of PLKs is widely associated with tumorigenesis and by this, PLKs have gained increasing significance as attractive targets in cancer with diagnostic, prognostic and therapeutic potential. PLK1 has proved to have strong clinical relevance as it was found to be over-expressed in different cancer types and linked to poor patient prognosis. Targeting the diverse functions of PLKs (tumor suppressor, oncogenic) are currently at the center of numerous investigations in particular with the inhibition of PLK1 and PLK4, respectively in multiple cancer trials. Functions of PLKs and the effects of their inhibition have been extensively studied in cancer cell culture models but information is rare on how these drugs affect benign tissues and organs. As a step further towards clinical application as cancer targets, mouse models therefore play a central role. Modelling PLK function in animal models, e.g., by gene disruption or by treatment with small molecule PLK inhibitors offers promising possibilities to unveil the biological significance of PLKs in cancer maintenance and progression and give important information on PLKs' applicability as cancer targets. In this review we aim at summarizing the approaches of modelling PLK function in mice so far with a special glimpse on the significance of PLKs in ovarian cancer and of orthotopic cancer models used in this fatal malignancy.

Recent progress in agents targeting polo-like kinases: Promising therapeutic strategies

Polo-like kinases (PLKs) play important roles in regulating multiple aspects of cell cycle and cell proliferation. In many cancer types, PLK family members are often dysregulated, which can lead to uncontrolled cell proliferation and aberrant cell division and has been shown to associate with poor prognosis of cancers. The key roles of PLK kinases in cancers lead to an enhanced interest in them as promising targets for anticancer drug development. In consideration of PLK inhibitors and some other anticancer agents, such as BRD4, EEF2K and Aurora inhibitors, exert synergy effects in cancer cells, dual-targeting of PLK and other cancer-related targets is regarded as an rational and potent strategy to enhance the effectiveness of single-targeting therapy for cancer treatment. This review introduces the PLK family members at first and then focuses on the recent advances of single-target PLK inhibitors and summarizes the corresponding SARs of them. Moreover, we discuss the synergisms between PLK and other anti-tumor targets, and sum up the current dual-target agents based on them.

Cytokinesis regulators as potential diagnostic and therapeutic biomarkers for human hepatocellular carcinoma

Cytokinesis, the final step of mitosis, is critical for maintaining the ploidy level of cells. Cytokinesis is a complex, highly regulated process and its failure can lead to genetic instability and apoptosis, contributing to the development of cancer. Human hepatocellular carcinoma is often accompanied by a high frequency of aneuploidy and the DNA ploidy pattern observed in human hepatocellular carcinoma results mostly from impairments in cytokinesis. Many key regulators of cytokinesis are abnormally expressed in human hepatocellular carcinoma, and their expression levels are often correlated with patient prognosis. Moreover, preclinical studies have demonstrated that the inhibition of key cytokinesis regulators can suppress the growth of human hepatocellular carcinoma. Here, we provide an overview of the current understanding of the signaling networks regulating cytokinesis, the key cytokinesis regulators involved in the initiation and development of human hepatocellular carcinoma, and their applications as potential diagnostic and therapeutic biomarkers.

miR-139-5p Loss-Mediated WTAP Activation Contributes to Hepatocellular Carcinoma Progression by Promoting the Epithelial to Mesenchymal Transition

Background: Hepatocellular carcinoma (HCC) is a primary aggressive gastrointestinal neoplasm that affects patients worldwide. It has been shown that Wilms' tumor 1-associating protein (WTAP) is frequently upregulated in various cancers. However, the potential role of WTAP in HCC remains largely unknown.

Methods: The expression levels of WTAP in human HCC tissues were determined by the western blotting and immunohistochemical (IHC) staining. A correlation between the WTAP expression, clinicopathological features, and the HCC prognosis was analyzed. The WTAP expression was silenced by short hairpin RNA (shRNA), and effects of the knockdown of WTAP on the proliferation and invasion of HCC cells were assessed. The microRNAs (miRNAs) involved in the regulation of the WTAP expression were identified by a bioinformatics analysis and further confirmed by in vitro assays.

Results: The expression levels of WTAP in liver cancer tissues were significantly elevated and compared with those in the adjacent normal tissues and significantly correlated with the clinical stage and prognosis in patients with HCC. Further investigation revealed that the knockdown of WTAP drastically suppressed HCC cell proliferation and invasion abilities. Luciferase reporter assay and validation experiments confirmed that WTAP was a direct target of miR-139-5p. Moreover, the overexpression of WTAP could partly abolish the inhibitory effects of miR-139-5p on the HCC cell growth and invasion. Mechanistically, we revealed that the miR-139-5p/WTAP axis regulated the HCC progression by controlling the epithelial to mesenchymal transition (EMT).

Conclusions: In summary, the results indicate that WTAP is a potential oncogene in HCC and miR-139-5p negatively regulates the WTAP expression. MiR-139-5p/WTAP can be utilized as a potential therapeutic target for HCC.

Dynamics of m6A RNA Methylome on the Hallmarks of Hepatocellular Carcinoma

Epidemiological data consistently rank hepatocellular carcinoma (HCC) as one of the leading causes of cancer-related deaths worldwide, often posing severe economic burden on health care. While the molecular etiopathogenesis associated with genetic and epigenetic modifications has been extensively explored, the biological influence of the emerging field of epitranscriptomics and its associated aberrant RNA modifications on tumorigenesis is a largely unexplored territory with immense potential for discovering new therapeutic approaches. In particular, the underlying cellular mechanisms of different hallmarks of hepatocarcinogenesis that are governed by the complex dynamics of m6A RNA methylation demand further investigation. In this review, we reveal the up-to-date knowledge on the mechanistic and functional link between m6A RNA methylation and pathogenesis of HCC.

Long Noncoding RNA TCONS_00068220 Promotes Breast Cancer Progression by Regulating Epithelial-Mesenchymal Transition Marker E-Cadherin

BACKGROUND Long noncoding RNAs (lncRNAs) play essential roles in the regulation of breast cancer development. We herein investigated the potential role of lncRNA TCONS_00068220 in breast cancer pathogenesis. MATERIAL AND METHODS The expression levels of TCONS_00068220 in breast cancer tissues were measured by qRT-PCR. Afterwards, TCONS_00068220 was (1) overexpressed in MCF-7 breast cancer cells, and (2) silenced in MDA-MB-231 cells. Then, CCK-8 and transwell assays were conducted to detect the impact of TCONS_00068220 on cell proliferation, migration, and invasion. The expression of the epithelial-mesenchymal transition (EMT) marker E-cadherin was detected by western blot assay after upregulation or downregulation of TCONS_00068220. RESULTS TCONS_00068220 was remarkably upregulated in breast cancer tissues compared with non-cancerous tissues. In addition, TCONS_00068220 level was significantly correlated with lymphatic metastasis, Ki67 index, clinical stage, and differentiation grade. All breast cancer cell lines displayed a higher expression level of TCONS_00068220 compared with the normal breast epithelial cell line MCF-10A. Furthermore, enhanced expression of TCONS_00068220 in MCF-7 cells promoted cell proliferation, migration, invasion, and EMT, whereas TCONS_00068220 knockdown in MDA-MB-231 cells led to the opposite results. E-cadherin was negatively regulated by TCONS_00068220 in both breast cancer tissues and cell lines. Finally, TCONS_00068220 regulated MCF-7 and MDA-MB-231 cell behaviors by downregulating E-cadherin. CONCLUSIONS TCONS_00068220 promotes breast cancer cell proliferation, migration, and invasion, while facilitating the process of EMT by interacting with E-cadherin and suppressing its expression. Therefore, it may potentially serve as an oncogene in breast cancer progression.

Polo-Like Kinase 4's Critical Role in Cancer Development and Strategies for Plk4-Targeted Therapy

Polo-like kinases (Plks) are critical regulatory molecules during the cell cycle process. This family has five members: Plk1, 2, 3, 4, and 5. Plk4 has been identified as a master regulator of centriole replication, and its aberrant expression is closely associated with cancer development. In this review, we depict the DNA, mRNA, and protein structure of Plk4, and the regulation of Plk4 at a molecular level. Then we list the downstream targets of Plk4 and the hallmarks of cancer associated with these targets. The role of Plk4 in different cancers is also summarized. Finally, we review the inhibitors that target Plk4 in the hope of discovering effective anticancer drugs. From authors' perspective, Plk4 might represent a valuable tumor biomarker and critical target for cancer diagnosis and therapy.

Y-Box Binding Protein-1 Promotes Epithelial-Mesenchymal Transition in Sorafenib-Resistant Hepatocellular Carcinoma Cells

Hepatocellular carcinoma is one of the most common cancer types worldwide. In cases of advanced-stage disease, sorafenib is considered the treatment of choice. However, resistance to sorafenib remains a major obstacle for effective clinical application. Based on integrated phosphoproteomic and The Cancer Genome Atlas (TCGA) data, we identified a transcription factor, Y-box binding protein-1 (YB-1), with elevated phosphorylation of Ser102 in sorafenib-resistant HuH-7^R cells. Phosphoinositide-3-kinase (PI3K) and protein kinase B (AKT) were activated by sorafenib, which, in turn, increased the phosphorylation level of YB-1. In functional analyses, knockdown of YB-1 led to decreased cell migration and invasion in vitro. At the molecular level, inhibition of YB-1 induced suppression of zinc-finger protein SNAI1 (Snail), twist-related protein 1 (Twist1), zinc-finger E-box-binding homeobox 1 (Zeb1), matrix metalloproteinase-2 (MMP-2) and vimentin levels, implying a role of YB-1 in the epithelial-mesenchymal transition (EMT) process in HuH-7^R cells. Additionally, YB-1 contributes to morphological alterations resulting from F-actin rearrangement through Cdc42 activation. Mutation analyses revealed that phosphorylation at S102 affects the migratory and invasive potential of HuH-7^R cells. Our collective findings suggest that sorafenib promotes YB-1 phosphorylation through effect from the EGFR/PI3K/AKT pathway, leading to significant enhancement of hepatocellular carcinoma (HCC) cell metastasis. Elucidation of the specific mechanisms of action of YB-1 may aid in the development of effective strategies to suppress metastasis and overcome resistance.

Glycogen Phosphorylase B Is Regulated by miR101-3p and Promotes Hepatocellular Carcinoma Tumorigenesis

Glycogen metabolism plays a key role in tumorigenesis. High expression levels of glycogen phosphorylase B (PYGB) were reported in several cancers and might be served as a prognostic biomarker for cancer from precancerous lesions. Previous studies indicated the high expression of PYGB in hepatocellular carcinoma (HCC) tissues. However, the detailed roles of PYGB in HCC, as well as the regulatory mechanisms, are still unclear. In this study, we confirmed that PYGB was overexpressed in HCC tissues. PYGB overexpression was significantly associated with an aggressive tumor phenotype and poor prognosis of HCC patients. Functionally, PYGB knockdown suppressed HCC cell proliferation, migration and invasion in vitro, as well as tumorigenesis and metastasis in vivo. Bioinformatics analysis indicated that PYGB overexpression might enhance epithelial to mesenchymal transition (EMT) in HCC. Moreover, miR-101-3p was identified to post-transcriptionally inhibit the expression of PYGB via binding to 3′-UTR of PYGB. Overexpression of PYGB antagonized the regulatory effect of miR-101-3p on cell proliferation, migration and invasion in HCC cells. In summary, our results suggest that miR-101-3p/PYGB axis has an important role in HCC and PYGB could be served as a novel prognostic biomarker and therapeutic target for improving the prognosis of HCC patients.

Construction of a disease-specific lncRNA-miRNA-mRNA regulatory network reveals potential regulatory axes and prognostic biomarkers for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a heterogeneous malignancy with a high incidence and poor prognosis. Exploration of the underlying mechanisms and effective prognostic indicators is conducive to clinical management and optimization of treatment. The RNA‐seq and clinical phenotype data of HCC were retrieved from The Cancer Genome Atlas (TCGA), and differential expression analysis was performed. Then, a differential lncRNA‐miRNA‐mRNA regulatory network was constructed, and the key genes were further identified and validated. By integrating this network with the online tool‐based ceRNA network, an HCC‐specific ceRNA network was obtained, and lncRNA‐miRNA‐mRNA regulatory axes were extracted. RNAs associated with prognosis were further obtained, and multivariate Cox regression models were established to identify the prognostic signature and nomogram. As a result, 198 DElncRNAs, 120 DEmiRNAs, and 2827 DEmRNAs were identified, and 30 key genes identified from the differential network were enriched in four cancer‐related pathways. Four HCC‐specific lncRNA‐miRNA‐mRNA regulatory axes were extracted, and SNHG11, CRNDE, MYLK‐AS1, E2F3, and CHEK1 were found to be related with HCC prognosis. Multivariate Cox regression analysis identified a prognostic signature, comprised of CRNDE, MYLK‐AS1, and CHEK1, for overall survival (OS) of HCC. A nomogram comprising the prognostic signature and pathological stage was established and showed some net clinical benefits. The AUC of the prognostic signature and nomogram for 1‐year, 3‐year, and 5‐year survival was 0.777 (0.657‐0.865), 0.722 (0.640‐0.848), and 0.630 (0.528‐0.823), and 0.751 (0.664‐0.870), 0.773 (0.707‐0.849), and 0.734 (0.638‐0.845), respectively. These results provided clues for the study of potential biomarkers and therapeutic targets for HCC. In addition, the obtained 30 key genes and 4 regulatory axes might also help elucidate the underlying mechanism of HCC.

Gene expression profile of lipopolysaccharide‑induced apoptosis of nucleus pulposus cells reversed by syringic acid

Apoptosis of nucleus pulposus (NP) cells has an important role in the process of intervertebral disc degeneration (IDD), and the search for novel compounds to prevent apoptosis from occurring is urgently required. In the present study, syringic acid (SyrA) was found to exhibit no cytotoxicity on NP cells, and was able to reverse the cytotoxicity, as well as the abnormal expression of Bcl-2 and caspase-3, that were induced by lipopolysaccharide (LPS). The transcriptomes of each group were then analyzed using RNA-Seq. A total of 65 differentially expressed genes (DEGs) were identified in LPS-stimulated groups (LPS group vs. control group), 819 DEGs were identified in the SyrA-reversed groups (SyrA plus LPS group vs. LPS group), and a further 25 DEGs were identified in the SyrA plus LPS group compared with the control group. Reverse transcription-quantitative PCR validation indicated that the alterations in expression of uroplakin 3B-like 1 (UPK3BL1), voltage-dependent calcium channel subunit α-2/δ-1 (CACNA2D1) and polo-like kinase 4 (PLK4) were consistent with the corresponding results of RNA-Seq, and that these genes were involved in both LPS-stimulation and SyrA-reversion processes. Kyoto Encyclopedia of Genes and Genomes analyses indicated that the DEGs in SyrA-reversed groups were involved in, amongst other pathways, ‘Autophagy-other’ and ‘Apoptosis-multiple species’. In conclusion, the addition of SyrA to the NP cells co-incubated with LPS appeared to help prevent the abnormal expression of mRNAs and apoptosis that had been identified in NP cells incubated with LPS alone. The potential mechanism underlying the reversion of SyrA might be attributed to the regulation of CACNA2D1 and PLK4.

SPATS2, negatively regulated by miR-145-5p, promotes hepatocellular carcinoma progression through regulating cell cycle

Spermatogenesis associated serine rich 2 (SPATS2) has been reported to contribute to the tumorigenesis of multiple malignancies. The molecular function of SPATS2 in hepatocellular carcinoma (HCC) is still not fully understood. In this study, we aimed to investigate the expression pattern and function roles of SPATS2 in HCC. The regulation of SPATS2 expression was also explored. We found that SPATS2 was highly expressed in HCC tissues in comparison with that in adjacent normal tissues. High expression of SPATS2 was associated with vascular invasion, advanced TNM stages, tumor multiplicity, and poor survival. Functionally, SPATS2 was found to promote the proliferation and metastasis of HCC cells both in vitro and in vivo, while knockdown of SPATS2 enhanced apoptosis and G1 arrest of HCC cells in vitro. Mechanistically, bioinformatics analysis revealed that MiR-145-5p directly targeted SPATS2 and functional rescue experiments verified that MiR-145-5p overexpression could abolish the effect of SPATS2 on the regulation of HCC malignant phenotype. Taken together, our findings suggest that SPATS2 functions as an oncogene in HCC. The MiR-145-5p/SPATS2 axis provides a novel mechanism underlying HCC progression and may serve as a potential therapeutic target for HCC.

CircRNA circ-0038718 promotes hepatocellular carcinoma progression through sponging miR-139-3p

Hepatocellular Carcinoma (HCC) is the main histological subtype of liver malignancy with poor prognosis. A growing body of evidence showed that Circular RNAs (circRNAs) are related to HCC tumorigenesis and progression. In this study, we investigated the function and regulation of circ-0038718 in HCC. We found that circ-0038718 was frequently elevated in HCC specimens and cell lines. High expression levels of circ-0038718 were correlated with unfavorable prognosis in HCC patients. Furthermore, we demonstrated that knockdown of circ-0038718 attenuated HCC cell proliferation and metastatic abilities, while overexpression of circ-0038718 resulted the converse effect. Silencing circ-0038717 inhibited HCC xenograft tumor development in vivo. Mechanistically, circ-0038718 acted as the sponge of tumor-suppressive miR-139-3p to regulate HCC progression. Rescue experiments suggested the oncogenic activity of circ-0038718 was partially exerted via modulating miR-139-3p expression. Inhibition of miR-139-3p abrogated the regulatory effect of circ-0038718 in HCC cells. In summary, our results unveiled that circ-0038718 could serve as an crucial regulator of HCC progression and provide a potential therapeutic target for HCC treatment.

WBP11 is required for splicing the TUBGCP6 pre-mRNA to promote centriole duplication

Centriole duplication occurs once in each cell cycle to maintain centrosome number. A previous genome-wide screen revealed that depletion of 14 RNA splicing factors leads to a specific defect in centriole duplication, but the cause of this deficit remains unknown. Here, we identified an additional pre-mRNA splicing factor, WBP11, as a novel protein required for centriole duplication. Loss of WBP11 results in the retention of ∼200 introns, including multiple introns in TUBGCP6, a central component of the γ-TuRC. WBP11 depletion causes centriole duplication defects, in part by causing a rapid decline in the level of TUBGCP6. Several additional splicing factors that are required for centriole duplication interact with WBP11 and are required for TUBGCP6 expression. These findings provide insight into how the loss of a subset of splicing factors leads to a failure of centriole duplication. This may have clinical implications because mutations in some spliceosome proteins cause microcephaly and/or growth retardation, phenotypes that are strongly linked to centriole defects.

CircRNA circ_POLA2 Promotes Cervical Squamous Cell Carcinoma Progression via Regulating miR-326/GNB1

Circular RNAs (circRNAs) are a group of non-coding RNAs that have an essential function in the development and progression of various cancers. The expression pattern and function of circRNA in cervical squamous cell carcinoma (CESC) are not fully understood. In the present study, we aimed to investigate the expression profiles and regulation mechanism of circRNA circ_POLA2 in CESC. Circ_POLA2 was highly expressed in CESC tissues and positively correlated with poor prognosis in CESC patients. Knockdown of circ_POLA2 using shRNA inhibited cervical cancer cell proliferation, migration, and invasion both in vitro and in vivo. Mechanistically, circ_POLA2 could sponge endogenous microRNA-326 (miR-326) and inhibit its expression. Furthermore, miR-326 negatively regulated G protein subunit beta 1 (GNB1) by targeting its 3'-UTR. Intriguingly, we found that GNB1 was overexpressed and associated with poor prognosis in CESC patients. Overexpression of GNB1 could antagonize the inhibitory effect of miR-326 on cervical cancer cell proliferation, migration, and invasion. In addition, we demonstrated that circ_POLA2/miR-326/GNB1 axis regulated ERK signaling. In conclusion, circ_POLA2 promotes cervical squamous cell carcinoma development and progression via regulating the miR-326/GNB1 axis, which might serve as a novel therapeutic target for CESC patients.

MicroRNA-19b-3p suppresses gastric cancer development by negatively regulating neuropilin-1

Background

Gastric cancer (GC) remains one of the most common digestive malignancies worldwide and ranked third causes of cancer-related death. Mounting evidence has revealed that miRNAs exert critical regulatory roles in GC development.

Methods

Immunohistochemistry (IHC) and western blot assay were performed to determine the protein expression levels of neuropilin-1 (NRP1) and mRNA levels were confirmed by quantitative RT-PCR (qRT-PCR) in GC tissues. Kaplan–Meier analysis was performed to evaluate the prognostic value of NRP1 in GC. Knockdown of NRP1 was conducted to analyse its function in vitro and vivo. Luciferase reporter assay, western blot and qRT-qPCR were employed to identify the miRNAs which directly targeted NRP1. Furthermore, Bioinformatics analysis and experimental verification were used to explore the potential molecular mechanism and signalling pathway.

Results

In the current study, we revealed that NRP1 was highly expressed in GC tumor tissues and was associated with poor prognosis in GC patients. NRP1 knockdown inhibited GC cell growth, migration and invasion in vitro, while suppressed GC xenograft tumor development in vivo. Bioinformatics analysis predicted that miR-19b-3p down-regulated NRP1 expression by targeting its 3′-UTR. Functional assay demonstrated that miR-19b-3p inhibited GC cell growth, migration and invasion via negatively regulating NRP1. Overexpression NRP1 partially reversed the regulatory effect of miR-19b-3p. Moreover, we showed that miR-19b-3p/NRP1 axis regulated the epithelial-to-mesenchymal transition and focal adhesion in GC, which might contribute the GC development and progression.

Conclusions

Taken together, our findings suggest a regulatory network of miR-19b-3p/NRP1 in GC development. The miR-19b-3p/NRP1 axis might be further explored as a potential diagnostic and therapeutic target in GC.

Overexpression of SOX4 induces up-regulation of miR-126 and miR-195 in LNCaP prostate cancer cell line

The present study aims to investigate the association between SOX4, Wnt signaling, and miRNAs under Wnt3 induction via bioinformatics analysis and functional essays. To briefly explore the expression of SOX4 protein in various types of cancer, we used ONCOMINE, a highly reputable cancer database, for comparison of its expression in prostate carcinoma relative to normal prostate gland. Concomitantly, we used CCLE to plot the copy number of SOX4 against its mRNA expression status in various cancerous cell lines to confirm the carcinogenesis role of SOX4. Afterward, whole profiling expression of microRNA in SOX4-stably expressed LNCaP cell line under the effect of Wnt3A were demonstrated. After identifying microRNA targets, STRING database and MIROB were used to explore the functional connection between proteins and microRNA with proteins. The results from our study shows that over-expressed of SOX4 was confirmed in both carcinogenesis tissue and cancer cell lines in Oncomine and CCLE database. In addition, five miRNAs, miR-16, miR-19a, miR320, miR-195, and miR-126, were differentially expressed in LNCaP cell line induced by Wnt3a. Pathway analysis of these targets proposed interaction networks of SOX4, Wnt3a with miR-126 and miR-195. Altogether, the miRNAs involved in Wnt and SOX4-mediated prostate cancer such as miR-126 and miR-195 could be potential biomarkers in prostate cancer.

E2F1 mediated DDX11 transcriptional activation promotes hepatocellular carcinoma progression through PI3K/AKT/mTOR pathway

The DEAD/DEAH box helicase 11 (DDX11) plays vital roles in regulating the initiation of DNA replication. However, its precise function and regulation in hepatocellular carcinoma (HCC) have never been reported yet. In the current study, we found that DDX11 was overexpressed in HCC tissues. High DDX11 expression was positively correlated with large tumor size, tumor multiplicity, late tumor-node-metastasis (TNM) stage and poor prognosis. Additional, gain-of-function and loss-of-function experimental results revealed that DDX11 overexpression promoted HCC cell proliferation, migration, invasion and inhibited cell apoptosis in vitro. Overexpression of DDX11 also enhanced HCC tumorigenicity in vivo. Furthermore, DDX11 was transcriptionally regulated by transcription factor E2F1 in HCC, as demonstrated by chromatin immunoprecipitation (Ch-IP) and luciferase reporter assays. Mechanistically, E2F1/DDX11 axis promoted HCC cell proliferation, migration and invasion, at least in part, through activating PI3K/AKT/mTOR signaling pathway. Conclusively, our study demonstrates that E2F1-enhanced DDX11 expression promotes HCC progression through PI3K/AKT/mTOR pathway and DDX11 might be a potential therapeutic and prognostic target for HCC treatment.

KIAA1429 promotes osteosarcoma progression by promoting stem cell properties and is regulated by miR-143-3p

Background: Osteosarcoma (OS) is the most common primary bone malignancy, it has a dismal prognosis and mainly affects the children and adolescents. Previous reports have demonstrated that aberrantly expressed KIAA1429 plays crucial roles in the carcinogenesis of several cancers, but its expression status and functional role in the progression of OS have not previously been investigated.Methods: Immunohistochemistry (IHC) and western blotting were conducted to determine KIAA1429 expression status in OS. The relationship between KIAA1429 expression and OS prognosis was analyzed based on public database and tissue microarray (TMA). Cell proliferation ability was evaluated by CCK8, EdU and colony formation assays, and Transwell and wound healing potential were also assessed in vitro. Xenograft nude mouse model was performed to elucidate the tumor growth in vivo. The main specific miRNA targeting KIAA1429 in OS cells was identified.Results: KIAA1429 expression is markedly overexpressed in OS, and elevated KIAA1429 expression is significantly associated with an unfavorable prognosis. Functional investigations demonstrate that KIAA1429 silencing could attenuate proliferation, migration and invasion abilities of OS in vitro, as well as tumor growth in vivo. Mechanistically, microRNA-143-3p (miR-143-3p) was identified as the crucial specific mediator of KIAA1429 expression in OS cells. Furthermore, restoring KIAA1429 expression could partially reverse miR-143-3p mediated tumor-inhibition effects. Additionally, we found that knockdown of KIAA1429 or ectopic overexpression of miR-143-3p could repress stemness cell properties and the inhibition could be partly abolished by overexpression of KIAA1429.Conclusions: In summary, this study establishes miR-143-3p/KIAA1429 axis as promising therapeutic target for OS patients.

Transcriptional regulation of microRNA-126a by farnesoid X receptor in vitro and in vivo

OBJECTIVES

Recent research has indicated the microRNA-126a (miR-126a) is an endothelial cell-specific and highly conserved endogenous small non-coding RNA molecule. It contributes to the vascular integrity and angiogenesis, but the molecular regulation mechanism of miR-126a remains unknown.

RESULTS

Herein, quantitative real-time polymerase chain reaction (qRT-PCR) results showed that Farnesoid X Receptor (FXR) activation promoted miR-126a expression in HepG2, LO2, and Hep1-6 cells. Furthermore, FXR was found to transcriptionally regulate the miR-126a by binding to its DR8 site. The binding site of FXR was confirmed on intron 6 or 7 of miR-126a host gene epidermal growth factor-like domain 7 (EGFL7) by luciferase reporter assays, electrophoretic mobility shift assays (EMSAs) and chromatin immunoprecipitation (ChIP) assays.

CONCLUSIONS

All these data collectively suggest that FXR regulates transcripts of miR-126a by binding to DR8 in miR-126a gene promoter. This study may provide a molecular therapeutic target for angiogenic disorders, aging, and liver failure.

NORFA, long intergenic noncoding RNA, maintains sow fertility by inhibiting granulosa cell death

Long intergenic non-coding RNAs (lincRNAs) have been proved to be involved in regulating female reproduction. However, to what extent lincRNAs are involved in ovarian functions and fertility is incompletely understood. Here we show that a lincRNA, NORFA is involved in granulosa cell apoptosis, follicular atresia and sow fertility. We found that NORFA was down-regulated during follicular atresia, and inhibited granulosa cell apoptosis. NORFA directly interacted with miR-126 and thereby preventing it from binding to TGFBR2 3'-UTR. miR-126 enhanced granulosa cell apoptosis by attenuating NORFA-induced TGF-β signaling pathway. Importantly, a breed-specific 19-bp duplication was detected in NORFA promoter, which proved association with sow fertility through enhancing transcription activity of NORFA by recruiting transcription factor NFIX. In summary, our findings identified a candidate lincRNA for sow prolificacy, and provided insights into the mechanism of follicular atresia and female fertility.

Circular RNA circ_0001105 Inhibits Progression and Metastasis of Osteosarcoma by Sponging miR-766 and Activating YTHDF2 Expression

Background

Circular RNAs (circRNAs) play vital roles in the modulation of tumor progression. This study explored the biological functions of circ_0001105 in the progression of osteosarcoma (OS).

Methods

qRT-PCR and in situ hybridization (ISH) were performed to detect the expression status of circ_0001105 in cells and tissues. Bioinformatics analysis, dual-luciferase reporter gene assay, Western blot and qRT-PCR were performed to determine the relationships among RNAs. The CCK-8, colony formation, EdU, transwell and wound healing assays were conducted to evaluate the cell growth, invasion and migration of OS cells. Tumor xenografts were established to investigate the effects of circ_0001105 on tumor growth in vivo. Lastly, the protein expression of YTHDF2 in OS tissues was measured using immunohistochemical staining.

Results

Data showed that circ_0001105 and YTHDF2 were significantly lower, while miR-766 was higher in OS tissues compared to adjacent tissues. Low expression of circ_0001105 or YTHDF2 was associated with poor survival of OS patients as demonstrated by the Kaplan-Meier analysis. In addition, miR-766 was identified as a direct binding target of circ_0001105 and YTHDF2. Ectopic overexpression of circ_0001105 or YTHDF2 significantly suppressed OS cell viability and invasion through regulating miR-766. Last, overexpression of circ_0001105 significantly attenuated in vivo tumor growth.

Conclusion

Our findings suggest that circ_0001105 inhibits OS progression, at least partially, by regulating miR-766/YTHDF2 signaling pathway.

P4HA2 contributes to cervical cancer progression via inducing epithelial-mesenchymal transition

Background: Cervical cancer is one of the most common gynaecological malignancies. Emerging studies have documented that prolyl-4-hydroxylase α subunit 2 (P4HA2) is involved in multiple processes of cancer progression. However, the functional roles of P4HA2 in cervical cancer progression remain to be elucidated.

Methods: P4HA2 mRNA and protein levels were examined in cervical cancer tissues and cell line by qRT-PCR and western blot. The correlation of the P4HA2 expression levels and prognosis of cervical cancer patients were analysed in TCGA cervical cancer cohort and tissue microarray (TMA) cohort. P4HA2 was silenced to evaluate its function on cervical cancer progression both in vitro and in vivo. Bioinformatics analysis was performed to investigate the underlying regulation mechanism of cervical cancer by P4HA2.

Results: We found that P4HA2 are markedly upregulated in cervical cancer tissues in comparison with adjacent non-neoplastic tissues. In addition, upregulation of P4HA2 was associated with shorter overall survival (OS) and relapse-free survival (RFS). Functionally, we demonstrated that P4HA2 knockdown attenuated cell proliferation, migration and invasion of cervical cancer cells. Furthermore, xenograft tumor mouse model experiment showed silencing P4HA2 significantly inhibited tumor growth in vivo. Mechanistically, bioinformatics analysis revealed that epithelial-mesenchymal transition (EMT) was involved in cervical cancer progression regulated by P4HA2 and we further confirmed knockdown P4HA2 suppressed the EMT process.

Conclusion: our results suggest that P4HA2 functions as an oncogene in promoting cervical cancer cell proliferation, migration and invasion by inducing EMT, which might be a promising prognostic factor and therapeutic target for cervical cancer.