miR‑145‑5p reduces proliferation and migration of hepatocellular carcinoma by targeting KLF5

lncRNA ENST00000422059 promotes cell proliferation and inhibits cell apoptosis in breast cancer by regulating the miR-145-5p/KLF5 axis

Krüppel-like zinc-finger transcription factor 5 (KLF5) is a vital regulator of breast cancer (BC) onset and progression. The mechanism by which KLF5 regulates BC is still not clearly known. In this study, bioinformatics analysis shows that BC-affected individuals with elevated KLF5 expression levels have poor clinical outcomes. We further verify that miR-145-5p regulated KLF5 expression to promote cell apoptosis and inhibit cell proliferation in BC via dual-luciferase reporter assay, western blot analysis, qRT-PCR, CCK-8 assay and cell apoptosis assay. In addition, based on bioinformatics analysis, the binding of ENST00000422059 with miR-145-5p is confirmed by dual-luciferase reporter assay. Subsequently, FISH, western blot analysis, qRT-PCR, CCK-8 and cell apoptosis assays verified that ENST00000422059 increases KLF5 protein expression by sponging miRNA to promote cell proliferation and inhibit cell apoptosis. Finally, ENST00000422059 is found to accelerate tumor progression by regulating the miR-145-5p/KLF5 axis in vivo. In conclusion, this study suggests that ENST00000422059 upregulates KLF5 by sponging miR-145-5p to promote BC progression.

MicroRNAs and their vital role in apoptosis in hepatocellular carcinoma: miRNA-based diagnostic and treatment methods

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies with high invasive and metastatic capability. Although significant advances have been made in the treatment of HCC, the overall survival rate of patients is still low. It is essential to explore accurate biomarkers for early diagnosis and prognosis along with therapeutic procedures to increase the survival rate of these patients. Anticancer therapies can contribute to induce apoptosis for the elimination of cancerous cells. However, dysregulated apoptosis and proliferation signaling pathways lead to treatment resistance, a significant challenge in improving efficient therapies. MiRNAs, short non-coding RNAs, play crucial roles in the progression of HCC, which regulate gene expression through post-transcriptional inhibition and targeting mRNA degradation in cancers. Dysregulated expression of multiple miRNAs is associated with numerous biological processes, including cell proliferation, apoptosis, invasion and metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and drug resistance in HCC. This review summarizes the role and potential efficacy of miRNAs in promoting and inhibiting cell proliferation and apoptosis in HCC, as well as the role of miRNAs in therapy resistance in HCC.

Pseudogene UBE2MP1 derived transcript enhances in vitro cell proliferation and apoptosis resistance of hepatocellular carcinoma cells through miR-145-5p/RGS3 axis

Pseudogenes are barely transcribed at normal, while the anomalous transcripts of them are mostly regarded as long non-coding RNAs (lncRNAs), which play potential functions in human tumorigenicity and development. The exact effects of pseudogene-derived transcripts on hepatocellular carcinoma (HCC) are ambiguous. According to our previous research and constructed database on the HCC-related lncRNAs, we noticed that UBE2MP1 was transcriptionally activated in HCC as a pseudogene from the ubiquitin-conjugating enzyme member UBE2M. In this study, we validated the high expression of the UBE2MP1 transcript in HCC and its adverse correlation with dismal outcomes for the patients. UBE2MP1 depletion at the transcript level significantly impaired cell proliferation and apoptosis resistance in HCC cell lines. Notably, we discovered that the UBE2MP1 transcript shared a specific sequence, binding to the miR-145-5p seed region with a typical ceRNA effect. Simultaneously, we verified an axis of miR-145-5p/RGS3 in HCC cells, which promoted cell proliferation and apoptosis resistance with significance. And modulation of UE2MP1 could remarkably affect RGS3 expression and consequentially influence HCC cell growth in vitro. And combined with the rescue experiment modulating either miR-145-5p or RGS3 furtherly indicated UBE2MP1 as an upstream regulator of the axis in promoting HCC cell growth and maintenance. Thus, our findings provide new strategies for HCC prevention and individual treatment.

RNA sequencing-based identification of the regulatory mechanism of microRNAs, transcription factors, and corresponding target genes involved in vascular dementia

Vascular dementia (VaD) is the second most common form of dementia with uncertain mechanisms and no effective treatments. microRNAs (miRNAs) and transcription factors (TFs) are considered regulatory factors of genes involved in many diseases. Therefore, this work investigated the aberrantly expressed miRNAs, TFs, corresponding target genes, and their co-regulatory networks in the cortex of rats with bilateral common carotid artery occlusion (2VO) to uncover the potential mechanism and biomarkers of VaD. Differentially expressed genes (DEGs), miRNAs (DEMs), and TFs (DETFs) were identified using RNA sequencing, and their interaction networks were constructed using Cytoscape. The results showed that rats with 2VO had declined cognitive abilities and neuronal loss in the cortex than sham rats. DEGs, DEMs, and DETFs were discriminated between rats with 2VO and sham rats in the cortex, as shown by the 13 aberrantly expressed miRNAs, 805 mRNAs, and 63 TFs. The miRNA-TF-target gene network was constructed, showing 523 nodes and 7237 edges. Five miRNAs (miR-5132-5p, miR-764-3p, miR-223-3p, miR-145-5p, and miR-122-5p), ten TFs (Mxi1, Nfatc4, Rxrg, Zfp523, Foxj2, Nkx6-1, Klf4, Klf5, Csrnp1, and Prdm6), and seven target genes (Serpine1, Nedd4l, Pxn, Col1a1, Plec, Trip12, and Tpm1) were chosen as the significant nodes to construct feed-forward loops (FFLs). Gene Ontology and pathway enrichment analysis revealed that these miRNA and TF-associated genes are mostly involved in the PI3K/Akt, neuroactive ligand–receptor interaction, calcium signaling, and Wnt signaling pathways, along with central locations around the cell membrane. They exert functions such as growth factor binding, integrin binding, and extracellular matrix structural constituent, with representative biological processes like vasculature development, cell–substrate adhesion, cellular response to growth factor stimulus, and synaptic transmission. Furthermore, the expression of three miRNAs (miR-145-5p, miR-122-5p, and miR-5132-5p), six TFs (Csrnp1, Klf4, Nfatc4, Rxrg, Foxj2, and Klf5), and five mRNAs (Serpine1, Plec, Nedd4l, Trip12, and Tpm1) were significantly changed in rats with VaD, in line with the outcome of RNA sequencing. In the potential FFL, miR-145-5p directly bound Csrnp1 and decreased its mRNA expression. These results might help the understanding of the underlying regulatory mechanisms of miRNA-TF-genes, providing potential therapeutic targets in VaD.

The roles and regulation of the KLF5 transcription factor in cancers

Krüppel‐like factor 5 (KLF5) is a member of the KLF family. Recent studies have suggested that KLF5 regulates the expression of a large number of new target genes and participates in diverse cellular functions, such as stemness, proliferation, apoptosis, autophagy, and migration. In response to multiple signaling pathways, various transcriptional modulation and posttranslational modifications affect the expression level and activity of KLF5. Several transgenic mouse models have revealed the physiological and pathological functions of KLF5 in different cancers. Studies of KLF5 will provide prognostic biomarkers, therapeutic targets, and potential drugs for cancers.

CircANKRD11 Knockdown Protects HPMECs from Cigarette Smoke Extract-Induced Injury by Regulating miR-145-5p/BRD4 Axis

Background

Chronic obstructive pulmonary disease (COPD) is a major cause of death because of its high incidence and mortality, which is chiefly resulted from cigarette smoke exposure. A large number of studies show that circular RNA (circRNA) participates in regulating COPD process. This study aims to reveal the role of circRNA ankyrin repeat domain 11 (circANKRD11) in cigarette smoke extract (CSE)-induced cell apoptosis, inflammation, and oxidative stress.

Methods

The expression of circANKRD11, microRNA-145-5p (miR-145-5p) and bromodomain-containing 4 (BRD4) mRNA was detected by quantitative real-time polymerase chain reaction. The expression of apoptosis-related proteins and BRD4 protein was determined by Western blot. Cell apoptosis was detected by flow cytometry and Western blot. Cell inflammation was demonstrated by determining the levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) through enzyme-linked immunosorbent assay. Oxidative stress was investigated by the reactive oxygen species (ROS) and malondialdehyde (MDA) determination assays as well as superoxide dismutase (SOD) activity assay. The binding relationship between miR-145-5p and circANKRD11 or BRD4 was predicted by circinteractome or MicroT_CDS online database, and identified by dual-luciferase reporter, RNA immunoprecipitation or RNA pull-down assay.

Results

CircANKRD11 and BRD4 expression were increased, whereas miR-145-5p expression was decreased in the lung tissues of smokers with or without COPD and CSE-induced HPMECs compared with the lung tissues of non-smokers as well as untreated HPMECs, respectively. CircANKRD11 silencing ameliorated CSE-induced cell apoptosis, inflammation, and oxidative stress. CircANKRD11 acted as a sponge of miR-145-5p, and regulated CSE-induced cell injury via sponging miR-145-5p. Additionally, miR-145-5p mimics protected against CSE-induced cell injury through targeting BRD4.

Conclusion

CircANKRD11 absence protected HPMECs from CSE-induced injury by regulating BRD4 through associating with miR-145-5p, which demonstrated that circANKRD11 had the potential to act as a diagnosis biomarker for smoker-caused COPD.

Roles of Krüppel-like factor 5 in kidney disease

Transcription factor Krüppel-like factor 5 (KLF5) is a member of the Krüppel-like factors' (KLFs) family. KLF5 regulates a number of cellular functions, such as apoptosis, proliferation and differentiation. Therefore, KLF5 can play a role in many diseases, including, cancer, cardiovascular disease and gastrointestinal disorders. An important role for KLF5 in the kidney was recently reported, such that KLF5 regulated podocyte apoptosis, renal cell proliferation, tubulointerstitial inflammation and renal fibrosis. In this review, we have summarized the available information in the literature with a brief description on how transcriptional, post-transcriptional and post-translational modifications of KLF5 modulate its function in a variety of organs including the kidney with a focus of its importance on the pathogenesis of various kidney diseases. Furthermore, we also have outlined the current and possible mechanisms of KLF5 activation in kidney diseases. These studies suggest a need for more systemic investigations, particularly for generation of animal models with renal cell-specific deletion or overexpression of KLF5 gene to examine direct contributions of KLF5 to various kidney diseases. This will promote further experimentation in the development of therapies to prevent or treat various kidney diseases.

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.

MiR-145 Regulates the Chemoresistance of Hepatic Carcinoma Cells Against 5-Fluorouracil by Targeting Toll-Like Receptor 4

BACKGROUND

5-fluorouracil (5-FU) is a common drug for hepatic carcinoma (HCC), but the drug resistance of clinical chemotherapy restricts its use. Studies have demonstrated that miRNA molecules can act as a chemoresistance regulator in drug resistance of tumors, whereas the role of miR-145 in the 5-FU-resistant HCC remains unclear.

OBJECTIVE

To explore the prognostic value of miR-145 in HCC and its molecular mechanism in 5-FU-resistant HCC cells.

METHODS

A qRT-PCR assay was conducted to quantify miR-145 in HCC tissues and 5-FU-resistant HCC cells. The Cell Counting Kit-8 (CCK-8) and flow cytometry were adopted to analyze the proliferation and apoptosis of 5-FU-resistant HCC cells. The Western blot was adopted to quantify toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and apoptosis-related proteins. Moreover, an in vivo tumor xenotransplantation of nude mice was conducted to determine the effect of miR-145 on 5-FU-resistant HCC cells.

RESULTS

MiR-145 was expressed lowly in HCC tissues and cells, and linked to high TNM staging and lymph node metastasis of HCC patients. Down-regulation of miR-145 indicated a poorer prognosis and it promoted drug resistance of HCC cells and inhibited cell apoptosis. In contrast, miR-145 overexpression improved the sensitivity of HCC cells to 5-FU and enhanced the inhibition of 5-FU on tumor growth. The luciferase reporter gene assay showed that TLR4 was the direct target of miR-145, and the Western blot assay revealed that overexpression of TLR4 reversed the inhibitory effect of miR-145 overexpression on TLR4 and MyD88 protein and the effects of it on apoptosis-related proteins.

CONCLUSION

MiR-145 is an inhibiting factor in HCC and can target TLR4 to mediate the chemoresistance of HCC, which may provide novel ideas for treating HCC.

Unique microRNA alterations in hepatocellular carcinomas arising either spontaneously or due to chronic exposure to Ginkgo biloba extract (GBE) in B6C3F1/N mice

Ginkgo biloba extract (GBE) is used in traditional Chinese medicine as a herbal supplement for improving memory. Exposure of B6C3F1/N mice to GBE in a 2-year National Toxicology Program (NTP) bioassay resulted in a dose-dependent increase in hepatocellular carcinomas (HCC). To identify key microRNAs that modulate GBE-induced hepatocarcinogenesis, we compared the global miRNA expression profiles in GBE-exposed HCC (GBE-HCC) and spontaneous HCC (SPNT-HCC) with age-matched vehicle control normal livers (CNTL) from B6C3F1/N mice. The number of differentially altered miRNAs in GBE-HCC and SPNT-HCC was 74 (52 up and 22 down) and 33 (15 up and 18 down), respectively. Among the uniquely differentially altered miRNAs in GBE-HCC, miR-31 and one of its predicted targets, Cdk1 were selected for functional validation. A potential miRNA response element (MRE) in the 3'-untranslated regions (3'-UTR) of Cdk1 mRNA was revealed by in silico analysis and confirmed by luciferase assays. In mouse hepatoma cell line HEPA-1 cells, we demonstrated an inverse correlation between miR-31 and CDK1 protein levels, but no change in Cdk1 mRNA levels, suggesting a post-transcriptional effect. Additionally, a set of miRNAs (miRs-411, 300, 127, 134, 409-3p, and 433-3p) that were altered in the GBE-HCCs were also altered in non-tumor liver samples from the 90-day GBE-exposed group compared to the vehicle control group, suggesting that some of these miRNAs could serve as potential biomarkers for GBE exposure or hepatocellular carcinogenesis. These data increase our understanding of miRNA-mediated epigenetic regulation of GBE-mediated hepatocellular carcinogenesis in B6C3F1/N mice.

CircABCC2 Regulates Hepatocellular Cancer Progression by Decoying MiR-665

Background: Numerous studies have shown that circular RNAs (circRNAs) play vital roles in tumor progression. However, how circRNAs function in hepatocellular cancer (HCC) remains mostly unclear.

Methods: We analyzed HCC circRNA expression via a microarray, and the expression of an upregulated circRNA, circABCC2, was detected. We next explored the function of circABCC2 in HCC via a series of experiments. We performed RNA immunoprecipitation (RIP) and luciferase assays to explore the competing endogenous RNA (ceRNA) function of circABCC2 in HCC.

Results: qRT-PCR verified that circABCC2 was overexpressed in HCC. Inhibition of circABCC2 suppressed HCC cell proliferation and invasion, but promoted apoptosis. Luciferase assays and RIP showed that circABCC2 and ABCC2 could directly bind to miR-665 and that circABCC2 could regulate ABCC2 expression by sponging miR-665.

Conclusions: In summary, circABCC2 regulates ABCC2 expression and HCC progression by sponging miR-665. circABCC2 could be used as a biomarker and therapeutic target in HCC.