miR-145-5p affects the differentiation of gastric cancer by targeting KLF5 directly

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1- extracellular signal-regulated kinase-1/2 axis

BACKGROUND

MicroRNAs (miRNAs) regulate gene expression and play a critical role in cancer physiology. However, there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer (GC).

AIM

To investigate the role and molecular mechanism of miRNA-145-5p (miR145-5p) in the progression of GC.

METHODS

Real-time polymerase chain reaction (RT-PCR) was used to detect miRNA expression in human GC tissues and cells. The ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays, respectively. Cell proliferation was measured using cell counting kit-8 and colony formation assays, and apoptosis was evaluated using flow cytometry. Expression of the epithelial-mesenchymal transition (EMT)-associated protein was determined by Western blot. Targets of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter system. Serpin family E member 1 (SERPINE1) expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical staining. The correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot analysis. The association between SERPINE1 and GC progression was also tested. A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and miR-145-5p. The mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude mice.

RESULTS

GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this miRNA. Overexpression of miR-145-5p was associated with decreased GC cell proliferation, invasion, migration, and EMT, and these effects were reversed by forcing SERPINE1 expression. Kaplan-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 expression. Nude mouse tumorigenesis experiments confirmed that miR-145-5p targets SERPINE1 to regulate extracellular signal-regulated kinase-1/2 (ERK1/2).

CONCLUSION

This study found that miR-145-5p inhibits tumor progression and is expressed in lower amounts in patients with GC. MiR-145-5p was found to affect GC cell proliferation, migration, and invasion by negatively regulating SERPINE1 levels and controlling the ERK1/2 pathway.

Downregulation of KLF5 by EBER1 via the ERK signaling pathway in EBV-positive nasopharyngeal carcinoma cells: implications for latent EBV infection

Nasopharyngeal carcinoma (NPC) carcinogenesis and malignant transformation are intimately associated with Epstein-Barr virus (EBV) infection. A zinc-fingered transcription factor known as Krüppel-like factor 5 (KLF5) has been shown to be aberrantly expressed in a number of cancer types. However, little is known about the regulatory pathways and roles of KLF5 in EBV-positive NPC. Our study found that KLF5 expression was significantly lower in EBV-positive NPC than in EBV-negative NPC. Further investigation revealed that EBER1, which is encoded by EBV, down-regulates KLF5 via the extracellular signal-regulated kinase (ERK) signalling pathway. This down-regulation of KLF5 by EBER1 contributes to maintaining latent EBV infection in NPC. Furthermore, we uncovered the biological roles of KLF5 in NPC cells. Specifically, KLF5 may influence the cell cycle, prevent apoptosis, and encourage cell migration and proliferation - all of which have a generally pro-cancer impact. In conclusion, these findings offer novel strategies for EBV-positive NPC patients' antitumour treatment.

PRMT5 activates KLF5 by methylation to facilitate lung cancer

The highly expressed oncogenic factor Krüppel-like factor 5 (KLF5) promotes various cancerous processes, such as cell growth, survival, anti-apoptosis, migration and metastasis, particularly in lung cancer. Nevertheless, the modifications to KLF5 after translation are poorly understood. Protein arginine methyltransferase 5 (PRMT5) is considered as an oncogene known to be involved in different types of carcinomas, including lung cancer. Here, we show that the expression levels of PRMT5 and KLF5 are highly expressed lung cancer. Moreover, PRMT5 interacts with KLF5 and facilitates the dimethylation of KLF5 at Arginine 41 in a manner that depends on methyltransferase activity. Downregulation or pharmaceutical suppression of PRMT5 reduces the expression of KLF5 and its downstream targets both in vitro and in vivo. Mechanistically, the dimethylation of KLF5 by PRMT5 promotes the maintenance and proliferation of lung cancer cells at least partially by stabilising KLF5 via regulation of the Akt/GSK3β signalling axis. In summary, PRMT5 methylates KLF5 to prevent its degradation, thereby promoting the maintenance and proliferation of lung cancer cells. These results suggest that targeting PRMT5/KLF5 axis may offer a potential therapeutic strategy for lung cancer.

The kruppel-like factor (KLF) family, diseases, and physiological events

The Kruppel-Like Factor family of regulatory proteins, which has 18 members, is transcription factors. This family contains zinc finger proteins, regulates the activation and suppression of transcription, and binds to DNA, RNA, and proteins. Klfs related to the immune system are Klf1, Klf2, Klf3, Klf4, Klf6, and Klf14. Klfs related to adipose tissue development and/or glucose metabolism are Klf3, Klf7, Klf9, Klf10, Klf11, Klf14, Klf15, and Klf16. Klfs related to cancer are Klf3, Klf4, Klf5, Klf6, Klf7, Klf8, Klf9, Klf10, Klf11, Klf12, Klf13, Klf14, Klf16, and Klf17. Klfs related to the cardiovascular system are Klf4, Klf5, Klf10, Klf13, Klf14, and Klf15. Klfs related to the nervous system are Klf4, Klf7, Klf8, and Klf9. Klfs are associated with diseases such as carcinogenesis, oxidative stress, diabetes, liver fibrosis, thalassemia, and the metabolic syndrome. The aim of this review is to provide information about the relationship of Klfs with some diseases and physiological events and to guide future studies.

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.

Emerging roles of miR-145 in gastrointestinal cancers: A new paradigm

Gastrointestinal (GI) carcinomas are a group of cancers affecting the GI tract and digestive organs, such as the gastric, liver, bile ducts, pancreas, small intestine, esophagus, colon, and rectum. MicroRNAs (miRNAs) are small functional non-coding RNAs (ncRNAs) which are involved in regulating the expression of multiple target genes; mainly at the post-transcriptional level, via complementary binding to their 3'-untranslated region (3'-UTR). Increasing evidence has shown that miRNAs have critical roles in modulating of various physiological and pathological cellular processes and regulating the occurrence and development of human malignancies. Among them, miR-145 is recognized for its anti-oncogenic properties in various cancers, including GI cancers. MiR-145 has been implicated in diverse biological processes of cancers through the regulation of target genes or signaling, including, proliferation, differentiation, tumorigenesis, angiogenesis, apoptosis, metastasis, and therapy resistance. In this review, we have summarized the role of miR-145 in selected GI cancers and also its downstream molecules and cellular processes targets, which could lead to a better understanding of the miR-145 in these cancers. In conclusion, we reveal the potential diagnostic, prognostic, and therapeutic value of miR-145 in GI cancer, and hope to provide new ideas for its application as a biomarker as well as a therapeutic target for the treatment of these cancer.

miRNAs orchestration of gallbladder cancer - Particular emphasis on diagnosis, progression and drug resistance

Gallbladder cancer (GBC) is characterized by a highly invasive nature and a poor prognosis, with adenocarcinoma being the main histological subtype. According to statistical data, patients diagnosed with advanced GBC have a survival rate of less than 5% for 5 years. Despite the novel therapeutic techniques, the unsatisfactory results could be related to the underlying biology of tumor cells and resistance to chemotherapy. Early diagnosis is more important than clinical therapy as it assists in determining the pathological stage of cancer and facilitates the selection of appropriate medication. Hence, it is very important to understand the precise pathogenesis of GBC and to discover potential novel biomarkers for early diagnosis of GBC. Non-coding RNAs, such as microRNAs, long non-coding RNAs, and circular RNAs, have been found to influence the transcriptional regulation of target genes associated with cancer, either directly or indirectly. microRNAs are a group of small, non-coding, single-stranded RNAs that are expressed endogenously. miRNAs play significant roles in various fundamental cellular processes. Therefore, miRNAs have the potential to serve as valuable biomarkers and therapeutic targets for GBC.

New insights into KLFs and SOXs in cancer pathogenesis, stemness, and therapy

Despite the development of cancer therapies, the success of most treatments has been impeded by drug resistance. The crucial role of tumor cell plasticity has emerged recently in cancer progression, cancer stemness and eventually drug resistance. Cell plasticity drives tumor cells to reversibly convert their cell identity, analogous to differentiation and dedifferentiation, to adapt to drug treatment. This phenotypical switch is driven by alteration of the transcriptome. Several pluripotent factors from the KLF and SOX families are closely associated with cancer pathogenesis and have been revealed to regulate tumor cell plasticity. In this review, we particularly summarize recent studies about KLF4, KLF5 and SOX factors in cancer development and evolution, focusing on their roles in cancer initiation, invasion, tumor hierarchy and heterogeneity, and lineage plasticity. In addition, we discuss the various regulation of these transcription factors and related cutting-edge drug development approaches that could be used to drug "undruggable" transcription factors, such as PROTAC and PPI targeting, for targeted cancer therapy. Advanced knowledge could pave the way for the development of novel drugs that target transcriptional regulation and could improve the outcome of cancer therapy.

Circular RNA circ_0005667 promotes cisplatin resistance of endometrial carcinoma cells by regulating IGF2BP1 through miR-145-5p

BACKGROUND

Circular RNA (circRNA) plays a significant role in cisplatin (DDP) resistance. The purpose of this study was to explore the role of circ_0005667 in DDP resistance of endometrial carcinoma (EC) cells.

METHODS

The expression of circular RNA circ_0005667, microRNA-145-5p (miR-145-5p) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) in DDP-sensitive and DDP-resistant EC tissues and EC cells was determined by quantitative real-time PCR (qRT-PCR). The expression of apoptosis-related proteins, drug resistance-related proteins and IGF2BP1 proteins were detected by western blot. The half-maximal inhibitory concentration (IC50) of DDP was determined using a cell counting kit-8 (CCK-8) assay. For functional assays, cell proliferation, migration, invasion and cell apoptosis were determined using 5-ethynyl-2'-deoxyuridine (EdU) assay, wound healing assay, transwell assay and flow cytometry assay, respectively. The binding relationship between miR-145-5p and circ_0005667 or IGF2BP1 was verified by dual-luciferase reporter assay. A xenograft experiment was applied to clarify the functional role of circ_0005667 in vivo.

RESULTS

Levels of circ_0005667 and IGF2BP1 were markedly increased, whereas miR-145-5p was downregulated in DDP-resistant EC tissues and cells. The circ_0005667 deficiency could enhance DDP sensitivity, inhibit cell proliferation, migration and invasion and promote cell apoptosis in DDP-resistant EC cells in vitro. Mechanistically, circ_0005667 modulated IGF2BP1 expression through sponging miR-145-5p. In addition, miR-145-5p depletion attenuated circ_0005667 silencing-induced effects in EC cells. The regulation of miR-145-5p in DDP resistance involved low IGF2BP1 expression. In vivo experiments revealed that circ_0005667 silencing could improve the sensitivity of the tumor to DDP.

CONCLUSION

Circ_0005667 enhanced DDP resistance in EC by elevating IGF2BP1 through sponging miR-145-5p.

MicroRNA-145-5p modulates Krüppel-like factor 5 and inhibits cell proliferation, migration, and invasion in nasopharyngeal carcinoma

Background

In several human cancers, Krüppel-like factor 5 (KLF5), a zinc finger transcription factor, can contribute to both tumor progression or suppression; however, the precise role of KLF5 in nasopharyngeal carcinoma (NPC) remains poorly understood. In this study, the association between KLF5 and microRNA-145-5p (miR-145-5p) in NPC cells was elucidated.

Results

Our results showed that KLF5 expression was up-regulated in NPC group compared to normal group. We found that KLF5 exhibited an oncogenic role in NPC cells. The upregulation of miR-145-5p inhibited the proliferation, migration, and invasion of NPC cells. It was observed that miR-145-5p could down-regulate the mRNA and protein expression of KLF5 in NPC cell lines. Additionally, the activity of focal adhesion kinase (FAK), a migration marker, was regulated by miR-145-5p and KLF5 in NPC cells.

Conclusions

The results of this study indicated that miR-145-5p could repress the proliferation, migration, and invasion of NPC cells via KLF5/FAK regulation, and could be a potential therapeutic target for patients with NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-022-00430-9.

HMGB3 Targeted by miR-145-5p Impacts Proliferation, Migration, Invasion, and Apoptosis of Breast Cancer Cells

This study focused on the investigation into how HMGB3 works in breast cancer (BC) progression. Firstly, we analyzed the relationship between HMGB3 and BC patients through the TCGA database. We performed qRT-PCR for determining the HMGB3 mRNA level and Western blot for detecting the protein level of HMGB3 in BC cell lines. CCK-8, flow cytometry, transwell, and wound healing assays were utilized to detect the effect of HMGB3 on BC cell phenotypes. Next, the prediction of the binding site shared by miR-145-5p and HMGB3 was performed by the bioinformatics method. The targeting relationship between miR-145-5p and HMGB3 was validated by using dual-luciferase assay. Finally, rescue experiments were employed for assessing the effect of the miR-145-5p/HMGB3 axis on BC cells. HMGB3 was demonstrated to have a high-level expression in BC cell lines and facilitated BC progression. On the contrary, miR-145-5p was shown a low-level expression in BC cell lines, which could target HMGB3. miR-145-5p restrained the proliferation, migration, and invasion of BC cells via inhibiting HMGB3.

Development of 5-FU-modified tumor suppressor microRNAs as a platform for novel microRNA-based cancer therapeutics

MicroRNA (miRNAs) are pleiotropic post-transcriptional modulators of gene expression. Their inherently pleiotropic nature makes miRNAs strong candidates for the development of cancer therapeutics, yet despite their potential, there remains a challenge to deliver nucleic acid-based therapies into cancer cells. We developed a novel approach to modify miRNAs by replacing the uracil bases with 5-fluorouracil (5-FU) in the guide strand of tumor suppressor miRNAs, thereby combining the therapeutic effect of 5-FU with tumor-suppressive effect of miRNAs to create a potent, multi-targeted therapeutic molecule without altering its native RNAi function. To demonstrate the general applicability of this approach to other tumor-suppressive miRNAs, we screened a panel of 12 novel miRNA mimetics in several cancer types, including leukemia, breast, gastric, lung, and pancreatic cancer. Our results show that 5-FU-modified miRNA mimetics have increased potency (low nanomolar range) in inhibiting cancer cell proliferation and that these mimetics can be delivered into cancer cells without delivery vehicle both in vitro and in vivo, thus representing significant advancements in the development of therapeutic miRNAs for cancer. This work demonstrates the potential of fluoropyrimidine modifications that can be broadly applicable and may serve as a platform technology for future miRNA and nucleic acid-based therapeutics.

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.

A time to heal: microRNA and circadian dynamics in cutaneous wound repair

Many biological systems have evolved circadian rhythms based on the daily cycles of daylight and darkness on Earth. Such rhythms are synchronised or entrained to 24-h cycles, predominantly by light, and disruption of the normal circadian rhythms has been linked to elevation of multiple health risks. The skin serves as a protective barrier to prevent microbial infection and maintain homoeostasis of the underlying tissue and the whole organism. However, in chronic non-healing wounds such as diabetic foot ulcers (DFUs), pressure sores, venous and arterial ulcers, a variety of factors conspire to prevent wound repair. On the other hand, keloids and hypertrophic scars arise from overactive repair mechanisms that fail to cease in a timely fashion, leading to excessive production of extracellular matrix (ECM) components such as such as collagen. Recent years have seen huge increases in our understanding of the functions of microRNAs (miRNAs) in wound repair. Concomitantly, there has been growing recognition of miRNA roles in circadian processes, either as regulators or targets of clock activity or direct responders to external circadian stimuli. In addition, miRNAs are now known to function as intercellular signalling mediators through extracellular vesicles (EVs). In this review, we explore the intersection of mechanisms by which circadian and miRNA responses interact with each other in relation to wound repair in the skin, using keratinocytes, macrophages and fibroblasts as exemplars. We highlight areas for further investigation to support the development of translational insights to support circadian medicine in the context of these cells.

Identification of invasion-metastasis associated MiRNAs in gallbladder cancer by bioinformatics and experimental validation

Background

Recent studies exploring the roles of invasion-metastasis associated miRNAs in gallbladder cancer (GBC) are limited. In the study, we aimed to identify the invasion-metastasis associated miRNAs in GBC by bioinformatics and experimental validation.

Methods

MiRNAs of different expression were identified by comparing GBC tumor samples with different survival from Gene Expression Omnibus database. MiRTarBase was used for identifying the potential target genes of miRNAs. Then, we performed Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. And miRNA-gene and protein–protein interaction (PPI) network were constructed for hub genes evaluation. We further explored and compared miR-642a-3p and miR-145-5p expression in both The Cancer Genome Atlas database and our hospital data. Finally, quantitative real-time PCR, wound healing assay, and Transwell assay were conducted to validate the invasion-metastasis associated miRNAs in GBC.

Results

In GSE104165 database, 25 up-regulated and 97 down-regulated miRNAs were detected with significantly different expression in GBC tumor samples. Then, 477 potential target genes were identified from the 2 most up-regulated miRNAs (miR-4430 and miR-642a-3p) and 268 genes from the 2 most down-regulated miRNAs (miR-451a and miR-145-5p). After GO and KEGG analysis, mTOR and PI3K-Akt signaling pathways were found associated with the potential target genes. Based on PPI network, the top 10 highest degree hub nodes were selected for hub genes. Furthermore, the miRNA-hub gene network showed significant miR-642a-3p up-regulation and miR-145-5p down-regulation in both GBC tissues and cell lines. In the experimental validation, miR-145-5p up-regulation and miR-642a-3p down-regulation were confirmed to suppress GBC invasion and metastasis.

Conclusions

MiR-642a-3p and miR-145-5p were identified as invasion-metastasis associated miRNAs via bioinformatics and experimental validation, and both up-regulation of miR-642a-3p and down-regulation of miR-145-5p would be served as novel treatment options for GBC in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03394-8.

Testis developmental related gene 1 promotes non-small-cell lung cancer through the microRNA-214-5p/Krüppel-like factor 5 axis

Non-small-cell lung cancer (NSCLC) is a frequent malignancy and has a high global incidence. Long noncoding RNAs (lncRNAs) are implicated in carcinogenesis and tumor progression. LncRNA testis developmental related gene 1 (TDRG1) plays a pivotal role in many cancers. This study researched the biological regulatory mechanisms of TDRG1 in NSCLC. Gene expression was assessed by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Changes in the NSCLC cell phenotypes were examined using 5-ethynyl-2'-deoxyuridine (EdU), cell counting kit-8 (CCK-8), wound healing, flow cytometry, and Transwell assays. The binding capacity between TDRG1, microRNA-214-5p (miR‑214-5p), and Krüppel-like factor 5 (KLF5) was tested using luciferase reporter and RNA immunoprecipitation (RIP) assays. In this study, we found that TDRG1 was upregulated in NSCLC samples. Functionally, TDRG1 depletion inhibited NSCLC cell growth, migration, and invasion and accelerated apoptosis. In addition, TDRG1 interacted with miR-214-5p, and miR-214-5p directly targeted KLF5. The suppressive effect of TDRG1 knockdown on NSCLC cellular processes was abolished by KLF5 overexpression. Overall, TDRG1 exerts carcinogenic effects in NSCLC by regulating the miR-214-5p/KLF5 axis.

MicroRNA miR-145-5p regulates cell proliferation and cell migration in colon cancer by inhibiting chemokine (C-X-C motif) ligand 1 and integrin α2

Colon cancer (CC), which has high morbidity and mortality, can be regulated by microRNAs. This study aimed to investigate the regulatory function of microRNA miR-145-5p in CC cells. Bioinformatics analysis was used to screen key genes in CC. The expression of miR-145-5p, chemokine (C-X-C motif) ligand 1 (CXCL1), and integrin α2 (ITGA2) in CC was confirmed by quantitative reverse transcription polymerase chain reaction and western blotting. After cell transfection, changes in proliferation and migration in CC cells were detected using the cell counting kit-8 (CCK-8), colony formation assay, and wound healing assay. A luciferase assay was conducted to confirm the interactome of miR-145-5p, CXCL1, and ITGA2 in CC cells. Bioinformatics analysis confirmed that CXCL1 and ITGA2 were key genes in CC. After performing several cell functional experiments, the results confirmed that upregulation of miR-145-5p attenuated proliferation and migration of CC cells. Luciferase assay and western blotting confirmed that CXCL1 and ITGA2 were targets of miR-145-5p, and their expression in CC could be suppressed by miR-145-5p. In conclusion, miR-145-5p is a tumor suppressor in CC and can inhibit the expression of CXCL1 and ITGA2.

KLF5 activates lncRNA DANCR and inhibits cancer cell autophagy accelerating gastric cancer progression

Cancer cell autophagy has been associated with the progression of gastric cancer (GC), but involvement of long noncoding RNAs (lncRNAs) remains unclear. Initial bioinformatics analysis has identified abnormally highly expressed KLF5 in GC, as well as the predicted regulatory mechanism associating with lncRNA DANCR, miR-194, and AKT2. The expression of KLF5, DANCR, and AKT2 in GC tissue was upregulated, and the expression of miR-194 was downregulated. We knocked KLF5 down and manipulated the expression of DANCR, miR-194, and AKT2 to characterize their roles in GC cell viability, autophagy, and apoptosis. The mechanistic investigations revealed that KLF5 activated the transcription of DANCR in the promoter region and elevated its expression. DANCR acted as a miR-194 sponge to repress its expression in GC. MiR-194 targeted and inhibited AKT2 expression. Silencing KLF5 augmented GC cell autophagy, apoptosis and impeded its viability through the DANCR/miR-194/AKT2 axis. The tumor-inhibiting properties of KLF5 knockdown were substantiated in vivo. Together, our study uncovered the oncogenic role of KLF5-dependent lncRNA DANCR transcription in GC in vivo and in vitro, which implicates the miR-194/AKT2 axis in tumor growth regulation, and it may be a potential therapeutic target for human GC.

LINC01123 promotes cell proliferation and migration via regulating miR-1277-5p/KLF5 axis in ox-LDL-induced vascular smooth muscle cells

The pathophysiological mechanism of carotid atherosclerosis (CAS) involves endothelial cell dysfunction, vascular smooth muscle cells (VSMCs), and macrophage activation, which ultimately leads to fibrosis of the vessel wall. lncRNA works weightily in the formation of CAS, but the function and mechanism of lncRNA LINC01123 in stable plaque formation are still equivocal. We collected blood samples from 35 CAS patients as well as 33 healthy volunteers. VSMCs treated with oxidized low-density lipoprotein (ox-LDL) were utilized as the CAS cell models. We applied qRT-PCR for detecting LINC01123, miR-1277-5p and KLF5 mRNA expression, CCK-8 method and BrdU test for determining cell proliferation, Transwell test for measuring cell migration, as well as Western blot for assaying KLF5 protein expression. Dual-luciferase reporter experiment was adopted for assessing the interaction between LINC01123 and miR-1277-5p, as well as KLF5 and miR-1277-5p. LINC01123 and KLF5 expression were dramatically up-regulated, while miR-1277-5p expression was down-regulated in CAS patients and ox-LDL-induced CAS cell models. Overexpressed LINC01123 notedly promoted VSMCs migration and proliferation. LINC01123 knockdown repressed cell proliferation and migration. Also, LINC01123 targeted miR-1277-5p and down-regulated its expression, while miR-1277-5p could negatively regulate KLF5 expression. LINC01123 is highly expressed in CAS patients, and promotes cell proliferation and migration via regulating miR-1277-5p/KLF5 axis in ox-LDL-induced VSMCs. It might be involved in the fibrous plaque formation.

The Partial Role of KLF4 and KLF5 in Gastrointestinal Tumors

Background

KLF4 and KLF5 are members of the KLF transcription factor family, which play an important role in many gastrointestinal tumors. To gain a deeper insight into its function and role, bioinformatics was used to analyze the function and role of KLF4 and KLF5 in gastrointestinal tumors.

Methods

Data were collected from several online databases. Gene Expression Profiling Interactive Analysis (GEPIA), UALCAN database analysis, Kaplan-Meier Plotter analysis, LOGpc system, the Pathology Atlas, and the STRING website were used to analyze the data. We download relevant data from TCGA and then perform GO enrichment and KEGG enrichment analysis. The effects of KLF5 on gastric cancer cell proliferation were measured by CCK-8 assay. The effect of KLF5 on the expression of CyclinD1 and MMP9 was detected by Western blot.

Results

KLF4 and KLF5 were differentially expressed in normal and tumor tissues of the gastrointestinal tract, and their differential expression is related to several genes or pathways. KEGG analysis showed that KLF5 was coexpressed with endocytosis-related genes. KLF5 promotes the proliferation of gastric cancer cells and the expression of metastasis-related molecules.

Conclusion

KLF4 and KLF5 are of great significance for developing gastrointestinal tumors and can be used as therapeutic targets.

SMILR Aggravates the Progression of Atherosclerosis by Sponging miR-10b-3p to Regulate KLF5 Expression

Over the past few decades, long noncoding RNAs (lncRNAs) have been widely accepted to be involved in various diseases, and smooth muscle enriched long noncoding RNA (SMILR) was reported to participate in the proliferation of vascular smooth muscle cells (VSMCs). Nevertheless, the molecular mechanisms of SMILR in atherosclerosis (AS) have not been fully explored. In this study, VSMCs and human mononuclear cells (U937) treated with oxidized low-density lipoprotein (ox-LDL) were used as cell models of AS. We found that the expression of SMILR was upregulated in the serum of AS patients and ox-LDL-induced AS cell models. SMILR knockdown inhibited cell proliferation while increasing cell apoptosis in the AS cell models. In addition, SMILR acted as a sponge for miR-10b-3p, and miR-10b-3p counteracted SMILR-mediated regulation of AS. Moreover, we confirmed that miR-10b-3p could bind with KLF5, and SMILR regulated KLF5 expression by competitively binding miR-10b-3p. Furthermore, miR-10b-3p modulated cell proliferation and apoptosis in AS by targeting KLF5. Finally, miR-10b-3p regulated AS progression in vivo by targeting KLF5. Overall, our study demonstrated that SMILR participated in the progression of AS by targeting the miR-10b-3p/KLF5 axis, which may provide some clues for future studies of AS.

LncRNA UCA1 promotes development of gastric cancer via the miR-145/MYO6 axis

Background

Long noncoding RNA (lncRNA), urothelial carcinoma-associated 1 (UCA1) is aberrantly expressed in multiple cancers and has been verified as an oncogene. However, the underlying mechanism of UCA1 in the development of gastric cancer is not fully understood. In the present study, we aimed to identify how UCA1 promotes gastric cancer development.

Methods

The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) data were used to analyze UCA1 and myosin VI (MYO6) expression in gastric cancer. Western blot and quantitative real-time PCR (QPCR) were performed to test the expression level of the UCA1/miR-145/MYO6 axis in gastric cancer cell lines and tissues. The roles of the UCA1/miR-145/MYO6 axis in gastric cancer in vitro and in vivo were investigated by CCK-8 assay, flow cytometry, siRNAs, immunohistochemistry, and a mouse xenograft model. The targeted relationship among UCA1, miR-145, and MYO6 was predicted using LncBase Predicted v.2 and TargetScan online software, and then verified by luciferase activity assay and RNA immunoprecipitation.

Results

UCA1 expression was higher but miR-145 expression was lower in gastric cancer cell lines or tissues, compared to the adjacent normal cell line or normal tissues. Function analysis verified that UCA1 promoted cell proliferation and inhibited cell apoptosis in the gastric cancer cells in vitro and in vivo. Mechanistically, UCA1 could bind directly to miR-145, and MYO6 was found to be a downstream target gene of miR-145. miR-145 mimics or MYO6 siRNAs could partly reverse the effect of UCA1 on gastric cancer cells.

Conclusions

UCA1 accelerated cell proliferation and inhibited cell apoptosis through sponging miR-145 to upregulate MYO6 expression in gastric cancer, indicating that the UCA1/miR-145/MYO6 axis may serve as a potential therapeutic target for gastric cancer.

Circular RNA VANGL1 knockdown suppressed viability, promoted apoptosis, and increased doxorubicin sensitivity through targeting miR-145-5p to regulate SOX4 in bladder cancer cells

Background

Bladder cancer is a common malignancy in the world. It is reported that circular RNA VANGL1 (circ_VANGL1) was involved in bladder cancer progression. However, the functional role and molecular mechanism of circ_VANGL1 in bladder cancer were still unclear.

Methods

The levels of circ_VANGL1, microRNA-145-5p (miR-145-5p), and Sex-determining region Y-related high-mobility group box 4 (SOX4) in bladder cancer tissues and cells were determined by quantitative real-time polymerase chain (RT-qPCR). The relative protein expression was detected by western blot. Cell counting kit-8 (CCK8) and flow cytometry analysis were used to measure cell viability, IC₅₀ value, and apoptosis rate. The interaction between miR-145-5p and circ_VANGL1 or SOX4 was predicted by online software starBase v2.0 or Targetscan and verified by the dual-luciferase reporter assay. Besides, xenograft mice model was used to detect the effects of circ_VANGL1 in vivo.

Results

The level of circ_VANGL1 and SOX4 was increased, while miR-145-5p was decreased in bladder cancer tissues and cells. Knockdown of circ_VANGL1 suppressed viability, while promoted apoptosis and increased doxorubicin sensitivity in bladder cancer cells. Moreover, circ_VANGL1 acted as a sponge for miR-145-5p. In addition, miR-145-5p partially reversed the effects of miR-145-5p knockdown in T24 and J82 cells. SOX4 was a target of miR-145-5p and negatively regulated by miR-145-5p. Furthermore, miR-145-5p regulated SOX4 to affect cell progression in bladder cancer cells, including viability, apoptosis, and doxorubicin sensitivity. Besides, circ_VANGL1 suppressed tumor growth and enhanced the doxorubicin sensitivity in bladder cancer in vivo.

Conclusion

circ_VANGL1 mediated cell viability, apoptosis, and doxorubicin sensitivity by regulating miR-145-5p/SOX4 axis in bladder cancer, providing a potential therapeutic target for bladder cancer therapy.

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.

miR-145-5p Inhibits the Proliferation, Migration, and Invasion of Esophageal Carcinoma Cells by Targeting ABRACL

Objective

The study is aimed at investigating the regulatory relationship between miR-145-5p and ABRACL, and has tried at clarifying the mechanisms underlying the proliferation, migration, and invasion of esophageal carcinoma (EC) cells.

Methods

Gene expression data related to EC were accessed from TCGA database, and the “edgeR” package was used to screen differentially expressed genes. TargetScan, miRDB, and miRTarBase databases were used to predict potential targets for the target miRNA miR-145-5p. qRT-PCR and Western blot were performed to assess the expression of miR-145-5p and ABRACL in EC cells. Dual-luciferase reporter assay was performed to validate the targeting relationship between miR-145-5p and ABRACL. Functional experiments including CCK-8 assay, Transwell migration, and invasion assays were used to detect the proliferation, migration, and invasion of EC cells.

Results

The expression of miR-145-5p was significantly decreased in EC, while ABRACL was remarkably increased. In addition, there was a negative correlation identified between miR-145-5p and ABRACL mRNA. Overexpressing miR-145-5p was able to suppress cell proliferation, migration, and invasion, whereas silencing miR-145-5p posed an opposite effect. In the meantime, ABRACL was identified as a direct target of miR-145-5p by dual-luciferase reporter assay. Furthermore, miR-145-5p could inhibit the expression of ABRACL, in turn inhibiting the proliferation, migration, and invasion of EC cells.

Conclusion

miR-145-5p functions on the proliferation, migration, and invasion of EC cells via targeting ABRACL, and it may be a novel therapeutic target in EC treatment.

LncRNA MALAT1/microRNA let-7f/KLF5 axis regulates podocyte injury in diabetic nephropathy

OBJECTIVE

The abnormal expression of microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) has been demonstrated to exert pivotal effects in human diseases. We focused on the functions of metastasis associated lung adenocarcinoma transcript 1 (MALAT1) and microRNA let-7f on diabetic nephropathy (DN).

METHODS

The diabetes (db/db) mice were treated with silenced MALAT1, then the baseline indicators, pathology changes, marker proteins of podocyte injury (nephrin, podocin, desmin and Cleaved caspase-3), oxidative stress indicators and inflammatory factors in renal tissues were determined. Murine podocyte MPC5 cells were stimulated by high glucose (HG) and transfected with sh-MALAT1 or let-7f mimic, then the cell migration, adhesion ability and apoptosis were evaluated. Moreover, the binding relationship between MALAT1 and let-7f, and the targeting relationship between let-7f and krüppel-like factor 5 (KLF5) were confirmed.

RESULTS

Silenced MALAT1 could improve baseline indicators of DN mice, and also improved pathology, increased nephrin and podocin expression, decreased desmin and Cleaved caspase-3 expression, and restrained oxidative stress and inflammatory reaction in their renal tissues. Additionally, elevated let-7f and reduced MALAT1 could restrict migration and apoptosis of HG-induced MPC5 cells, and promoted the cell adhesion ability.

CONCLUSION

Results in our research indicated that the reduced MALAT1 could relieve the podocyte injury in DN by upregulating let-7f and inhibiting KLF5, which may be helpful for DN therapy.

Curcumol inhibits KLF5-dependent angiogenesis by blocking the ROS/ERK signaling in liver sinusoidal endothelial cells

AIMS

Liver fibrosis is a difficult problem in the medical field. We previously reported that curcumol, a bioactive substance, may inhibit the pathological angiogenesis of liver sinusoidal endothelial cells (LSECs) and play a good anti-hepatic fibrosis effect. However, the mechanism of curcumol inhibiting angiogenesis in LSEC needs to be further clarified. Here, we focus on how curcumol inhibits LSEC angiogenesis in liver fibrosis.

MATERIALS AND METHODS

Primary rat LSECs were cultured in vitro, and various molecular experiments including real-time PCR, western blot, immunofluorescence, tube formation assay and transwell migration assay were used to clarify the potential mechanism of curcumol. Carbon tetrachloride (CCl4) was applied to create a mouse liver fibrosis model. Blood and livers were taken to elucidate the efficacy of curcumol in vivo.

KEY FINDINGS

We found that curcumol could effectively inhibit LSEC angiogenesis in vitro. Interestingly, this process may depend on curcumol's inhibition of the expression of transcription factor KLF5. Mice experiment also showed that curcumol could alleviate chronic liver injury by reducing KLF5 expression. In addition, we suggested that curcumol could reduce the production of mitochondrial ROS and improve mitochondrial morphology in LSEC. More importantly, we proved that curcumol could suppress KLF5-mediated LSEC angiogenesis by inhibiting ROS/ERK signaling.

SIGNIFICANCE

We suggested that transcription factor KLF5 could be considered as a new target molecule of curcumol in improving liver fibrosis, and pointed out that curcumol targeted ROS/ERK-mediated KLF5 expression could inhibit LSEC angiogenesis. This provided a new theoretical basis for curcumol to ameliorate liver fibrosis.

MiR-187 suppresses non-small-cell lung cancer cell proliferation by targeting FGF9

Non-small-cell lung cancer (NSCLC) is the main pathological type of lung cancer and has a low overall five-year survival rate. miR-187 has been reported to play major roles in various tumor types. In this study, we explored the impact of miR-187 on NSCLC. qRT-PCR results demonstrated that miR-187 expression is lower in NSCLC and cancer cells than normal tissues and normal lung cells. miR-187 expression levels are associated with tumor size, TNM stage and overall survival rate. MTS and colony formation assays showed that high miR-187 expression inhibits NSCLC cell proliferation and colony formation ability, and flow cytometry showed that miR-187 overexpression induces cell cycle arrest at the G0/G1 phase. A luciferase reporter assay showed that FGF9 is a target of miR-187. miR-187 overexpression reduces the expression of FGF9, cyclin D1 CDK4 and CDK6. Therefore, miR-187 may present a new NSCLC treatment target by regulates cyclins-related protein expression.

Long Non-Coding RNA LINC01089 Enhances the Development of Gastric Cancer by Sponging miR-145-5p to Mediate SOX9 Expression

BACKGROUND

Long non-coding RNAs (lncRNAs) have potential regulatory effects in oncogenesis. Previous studies showed that several lncRNAs could participate in the progression of gastric cancer (GC). However, the specific biological mechanisms in GC are still unclear. We analyzed an lncRNA microarray of GC and selected LINC01089 for study.

METHODS

LINC01089 expression in GC was tested by qRT-PCR. GC cell proliferation was assessed using CCK-8 and EdU assays. Cell invasion was assessed using the Transwell assay. A dual-luciferase reporter gene assay and bioinformatics assay were performed to detect potential targets of LINC01089. Additionally, RNA immunoprecipitation and Western blot assays were performed to clarify their interactions and roles in the regulation of GC progression.

RESULTS

High LINC01089 expression was observed in GC cells. LINC01089 overexpression notably expedited cell migration, proliferation, and invasion. LINC01089 positively regulated SOX9 expression by competitively binding to microRNA (miR-145-5p).

CONCLUSION

LINC01089 competitively binds to miR-145-5p to mediate SOX9 expression. LINC01089 may participate in the progression of GC.

MiR-145-5p suppresses the proliferation, migration and invasion of gastric cancer epithelial cells via the ANGPT2/NOD_LIKE_RECEPTOR axis

Objective

This study aimed to investigate the relationship among miR-145-5p, ANGPT2 and the NOD_LIKE_RECEPTOR pathway, thereby revealing the molecular mechanism of these three factors underlying the proliferation, migration and invasion of gastric cancer (GC) epithelial cells.

Methods

qRT-PCR was carried out to detect the expression of miR-145-5p and ANGPT2 mRNA. Western blot was performed to test the protein levels of ANGPT2 as well as NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway. The targeting relationship between miR-145-5p and ANGPT2 was verified via a dual-luciferase reporter gene assay. The proliferation, migration and invasion of GC cells were detected through MTT and Transwell assays, respectively.

Results

The expression of miR-145-5p was significantly down-regulated in GC cells, while that of ANGPT2 was notably up-regulated. MiR-145-5p directly bound with the 3′-UTR of ANGPT2 mRNA, thereby targeting ANGPT2 after transcription. Overexpression of miR-145-5p inhibited the proliferation, migration and invasion of GC cells by suppressing ANGPT2. Moreover, low expression of ANGPT2 affected the protein levels of NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway, thus weakening the abilities of cell proliferation, migration and invasion.

Conclusions

MiR-145-5p plays an important role in GC epithelial cells, and it can affect cell proliferation, migration and invasion of GC cells by targeting ANGPT2 and regulating the NOD_LIKE_RECEPTOR pathway. Overall, our study further elucidates the molecular mechanism underlying the malignant progression of GC.

Small RNAs, Big Diseases

The past two decades have seen extensive research done to pinpoint the role of microRNAs (miRNAs) that have led to discovering thousands of miRNAs in humans. It is not, therefore, surprising to see many of them implicated in a number of common as well as rare human diseases. In this review article, we summarize the progress in our understanding of miRNA-related research in conjunction with different types of cancers and neurodegenerative diseases, as well as their potential in generating more reliable diagnostic and therapeutic approaches.

miR-145-5p suppresses proliferation, metastasis and EMT of colorectal cancer by targeting CDCA3

MicroRNAs play a critical role in regulating the carcinogenesis of colorectal cancer (CRC). Even though its role is unclear in CRC, miR-145-5p has been reported to have anti-oncogene properties in several tumors. Our research examined the function of miR-145-5p in CRC and the potential underlying mechanism. From the bioinformatics and qRT-PCR analysis, miR-145-5p levels were lower in CRC samples and cell lines. LoVo and SW480 cells were treated with miR-145-5p mimics and inhibitor, respectively. Cell cycle, CCK-8 and EdU assays revealed that overexpression of miR-145-5p suppressed cell viability and G1/S phase transition. Conversely, miR-145-5p inhibitor promoted cell growth and cell cycle transition. Elevated miR-145-5p expression also suppressed the migration, invasion and EMT of CRC cells, while miR-145-5p reduction had a reverse effect. CDCA3 was identified as a downstream effector of miR-145-5p and had a negative correlation with the miR-145-5p expression in CRC. In addition, co-transfection of miR-145-5p inhibitor and si-CDCA3 showed that CDCA3 in SW480 cells could reverse the effect caused by miR-145-5p. In conclusion, our findings demonstrated that miR-145-5p could act as a tumor suppressor in CRC by targeting CDCA3, and serve as a diagnostic and therapeutic biomarker of CRC.

MicroRNA‑145‑5p inhibits osteosarcoma cell proliferation by targeting E2F transcription factor 3

Osteosarcoma is a common type of bone tumor that primarily occurs in children and young adults. MicroRNA (miRNA/miR) dysregulation is associated with the progression of osteosarcoma; therefore, the aim of the present study was to investigate the biological functions and molecular mechanisms of miR-145-5p in osteosarcoma. The expression of miR-145-5p in osteosarcoma tissues and cell lines was quantified using reverse transcription-quantitative PCR (RT-qPCR). The effect of miR-145-5p on the proliferation of osteosarcoma cells was detected using Cell Counting Kit-8 and colony formation assays, as well as cell cycle distribution analysis. The effect of miR-145-5p on tumor growth was further investigated in vivo using a subcutaneous tumor model in nude mice. The interaction between miR-145-5p and E2F transcription factor 3 (E2F3) was determined using bioinformatics analysis, a luciferase assay, RT-qPCR and western blotting. The results revealed that miR-145-5p expression was decreased in osteosarcoma cell lines and tissues compared with the corresponding normal controls. Increased miR-145-5p expression inhibited the proliferation and colony formation ability of osteosarcoma cells, and induced G₁ phase arrest. Furthermore, mice injected with tumor cells overexpressing miR-145-5p exhibited smaller tumors than those in the control group. Further investigation revealed that miR-145-5p binds to and decreases the expression of E2F3. In addition, the mRNA levels of E2F3 were negatively associated with miR-145-5p in osteosarcoma tissues, and increasing E2F3 expression abrogated the inhibitory effects of miR-145-5p on osteosarcoma cells. Collectively, the results obtained in the present study suggest that miR-145-5p may suppress the progression of osteosarcoma, and may serve as a useful biomarker for the diagnosis of osteosarcoma, as well as a therapeutic target.

Circular RNA circMAN2B2 promotes growth and migration of gastric cancer cells by down-regulation of miR-145

Background

CircMAN2B2 is a newly discovered circRNA that has been found to be an oncogene in lung cancer and glioma. The present study was designed to reveal the role of circMAN2B2 in gastric carcinoma (GC).

Methods

qRT‐PCR method was utilized to examine circMAN2B2 expression in GC tissues and paracancerous tissues. Next, circMAN2B2 expression in SNU‐16 and AGS cells was silenced by transfection. CCK‐8 assay, colony formation assay, flow cytometer, Transwell assay, and Western blot were conducted for testing cell phenotype changes. Further, the downstream genes and signaling were uncovered by qRT‐PCR and Western blot.

Results

As relative to paracancerous tissues, circMAN2B2 was high‐expressed in GC tissues. Silence of circMAN2B2 clearly declined SNU‐16 and AGS cells viability, survival, migration but enhanced apoptosis. Meanwhile, silence of circMAN2B2 induced the cleavage of caspases (−3 and −9), down‐regulation of MMPs (−2 and −9), and up‐regulation of miR‐145. The impacts of circMAN2B2 silence toward SNU‐16 and AGS cells were attenuated by miR‐145 silence. Moreover, circMAN2B2 silence deactivated PI3K, AKT while activated JNK through regulating miR‐145.

Conclusion

This work presented the oncogenic function of circMAN2B2 in GC cells growth and migration. CircMAN2B2 exerted its function possibly through regulating miR‐145 as well as PI3K/AKT and JNK pathways.

CircDUSP16 promotes the tumorigenesis and invasion of gastric cancer by sponging miR-145-5p

BACKGROUND

Circular RNAs (circRNAs) as a novel subgroup of non-coding RNAs act a critical role in the pathogenesis of gastric cancer (GC). However, the underlying mechanisms by which hsa_circ_0003855 (circDUSP16) contributes to GC are still undocumented.

MATERIALS

The differentially expressed circRNAs were identified by GEO database. The association of circDUSP16 or miR-145-5p expression with clinicopathological features and prognosis in GC patients was analyzed by FISH and TCGA-seq data set. Loss- and gain-of-function experiments as well as a xenograft tumor model were performed to assess the role of circDUSP16 in GC cells. circDUSP16-specific binding with miR-145-5p was confirmed by bioinformatic analysis, luciferase reporter, and RNA immunoprecipitation assays.

RESULTS

The expression levels of circDUSP16 were markedly increased in GC tissue samples and acted as an independent prognostic factor of poor survival in patients with GC. Knockdown of circDUSP16 repressed the cell viability, colony formation, and invasive potential in vitro and in vivo, but ectopic expression of circDUSP16 reversed these effects. Moreover, circDUSP16 possessed a co-localization with miR-145-5p in the cytoplasm, and acted as a sponge of miR-145-5p, which attenuated circDUSP16-induced tumor-promoting effects and IVNS1ABP expression in GC cells. MiR-145-5p had a negative correlation with circDUSP16 expression and its low expression was associated with poor survival in GC patients.

CONCLUSIONS

CircDUSP16 facilitates the tumorigenesis and invasion of GC cells by sponging miR-145-5p, and may provide a novel therapeutic target for GC.

MiR-505 suppressed the growth of hepatocellular carcinoma cells via targeting IGF-1R

Hepatocellular carcinoma (HCC) is one of the most common cancers globally. An increasing body of evidence has demonstrated the critical function of microRNAs (miRNAs) in the initiation and progression of human cancers. Here, we showed that miR-505 was down-regulated in HCC tissues and cell lines. Reduced expression of miR-505 was significantly correlated with the worse prognosis of HCC patients. Overexpression of miR-505 suppressed the proliferation, colony formation and induced apoptosis of both HepG2 and Huh7 cells. Further mechanism study uncovered that miR-505 bound the 3'-untranslated region (3'-UTR) of the insulin growth factor receptor (IGF-1R) and inhibited the expression of IGF-1R in HCC cells. The down-regulation of IGF-1R by miR-505 further suppressed the phosphorylation of AKT at the amino acid S473. Consistently, the abundance of glucose transporter (GLUT) 1 (GLUT1) was reduced with the overexpression of miR-505. Down-regulation of GLUT1 by miR-505 consequently attenuated the glucose uptake, lactate production and ATP generation of HCC cells. Collectively, our results demonstrated the tumor suppressive function of miR-505 possibly via inhibiting the glycolysis of HCC cells. These findings suggested miR-505 as an interesting target for designing anti-cancer strategy in HCC.

miR-134 inhibits osteosarcoma cell invasion and metastasis through targeting MMP1 and MMP3 in vitro and in vivo

miR-134 has been shown to be associated with angiogenesis and the progression of osteosarcoma. This study further assessed the effects of miR-134 expression on osteosarcoma cell migration, invasion, and metastasis in vitro and in a nude mouse xenograft model, exploring the underlying molecular events. Luciferase reporter assays revealed that miR-134 directly targets the 3'-UTRs of MMP1 and MMP3 to reduce their expression in osteosarcoma cells. In conclusion, overexpression of miR-134 suppresses osteosarcoma cell invasion and metastasis through the inhibition of MMP1 and MMP3 expression. We propose miR-134 as an attractive novel therapeutic target for the treatment of osteosarcoma.