miR-15b-5p facilitates the tumorigenicity by targeting RECK and predicts tumour recurrence in prostate cancer

Identification of miRNA signature in cancer-associated fibroblast to predict recurrent prostate cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) are one of the major components of prostate stromal cells, which play a crucial part in tumor development and treatment resistance. This study aimed to establish a model of CAFs-related microRNAs (miRNAs) to assess prognostic differences, tumor microenvironments, and screening of anticancer drugs by integrating data from single-cell RNA sequencing (scRNA-seq) and bulk RNA sequencing (buRNA-seq).

METHODS

scRNA-seq and buRNA-seq data of primary prostate cancer (PCa) were downloaded from Gene Expression Omnibus and The Cancer Genome Atlas databases. Statistical methods including Least absolute shrinkage and selection operator (Lasso), Lasso penalized, Random Forest, Random Forest Combination, and Support Vector Machine (SVM) were performed to select hub miRNAs. Pathway analyses and assessment of infiltrating immune cells were conducted using Gene Set Enrichment Analysis and the CIBERSORT algorithm. The expression of CAFs-related miRNAs in fibroblast cell lines were validated through quantitative real-time PCR. Cell Counting Kit 8 (CCK8), wound-healing, clone formation, and cell migration assays were used to explore cell proliferation, growth, and migration in vitro. A mouse xenograft model was established to investigate the effect of CAFs on tumor growth in vivo.

RESULTS

Through single-cell transcriptomics analysis in 34 PCa patients, 89 CAFs-related mRNAs were identified. A prognostic model based on 9 CAFs-related miRNAs (hsa-miR-1258, hsa-miR-133b, hsa-miR-222-3p, hsa-miR-145-3p, hsa-miR-493-5p, hsa-miR-96-5p, hsa-miR-15b-5p, hsa-miR-106b-5p, and hsa-miR-191-5p) was established to predict biochemical recurrence (BCR). We have determined through two prediction methods that NVP-TAE684 may be the optimal targeted therapy drug for treating CAFs. Downregulation of hsa-miR-106b-5p in CAFs significantly suppressed cell proliferation, migration, and colony formation in vitro. In vivo studies using a xenograft model further confirmed that hsa-miR-106b-5p downregulation significantly reduced tumor growth.

CONCLUSION

Our findings conducted an integrated bioinformatic analysis to develop a CAFs-related miRNAs model that provides prognostic insights into individualized and precise treatment for prostate adenocarcinoma patients. Downregulation of miR-106b-5p in CAFs significantly suppressed tumor growth, suggesting a potential therapeutic target for cancer treatment.

MiR-21 Regulates Growth and Migration of Cervical Cancer Cells by RECK Signaling Pathway

Expression of miR-21 has been found to be altered in almost all types of cancers, and it has been classified as an oncogenic microRNA. In addition, the expression of tumor suppressor gene RECK is associated with miR-21 overexpression in high-grade cervical lesions. In the present study, we analyze the role of miR-21 in RECK gene regulation in cervical cancer cells. To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression using siRNAs. We analyzed the expression of miR-21 and RECK, as well as functional effects on cell proliferation and migration. We found that in cervical cancer cells, there was an inverse correlation between miR-21 expression and RECK mRNA and protein expression. SiRNAs to miR-21 increased luciferase reporter activity in construct plasmids containing the RECK-3'-UTR microRNA response elements MRE21-1, MRE21-2, and MRE21-3. The role of miR-21 in cell proliferation was also analyzed, and cancer cells transfected with siRNAs exhibited a markedly reduced cell proliferation and migration. Our findings indicate that miR-21 post-transcriptionally down-regulates the expression of RECK to promote cell proliferation and cell migration inhibition in cervical cancer cell survival. Therefore, miR-21 and RECK may be potential therapeutic targets in gene therapy for cervical cancer.

Biological and clinical significance of the glypican-3 gene in human lung adenocarcinoma: An in silico analysis

Glypican-3 (GPC3), a membrane-bound heparan sulfate proteoglycan, has long been found to be dysregulated in human lung adenocarcinomas (LUADs). Nevertheless, the function, mutational profile, epigenetic regulation, co-expression profile, and clinicopathological significance of the GPC3 gene in LUAD progression are not well understood. In this study, we analyzed cancer microarray datasets from publicly available databases using bioinformatics tools to elucidate the above parameters. We observed significant downregulation of GPC3 in LUAD tissues compared to their normal counterparts, and this downregulation was associated with shorter overall survival (OS) and relapse-free survival (RFS). Nevertheless, no significant differences in the methylation pattern of GPC3 were observed between LUAD and normal tissues, although lower promoter methylation was observed in male patients. GPC3 expression was also found to correlate significantly with infiltration of B cells, CD8+, CD4+, macrophages, neutrophils, and dendritic cells in LUAD. In addition, a total of 11 missense mutations were identified in LUAD patients, and ~1.4% to 2.2% of LUAD patients had copy number amplifications in GPC3. Seventeen genes, mainly involved in dopamine receptor-mediated signaling pathways, were frequently co-expressed with GPC3. We also found 11 TFs and 7 miRNAs interacting with GPC3 and contributing to disease progression. Finally, we identified 3 potential inhibitors of GPC3 in human LUAD, namely heparitin, gemcitabine and arbutin. In conclusion, GPC3 may play an important role in the development of LUAD and could serve as a promising biomarker in LUAD.

A tissue miRNA expression pattern is associated with disease aggressiveness of localized prostate cancer

BACKGROUND

Prostate cancer (PCa) is a heterogeneous malignancy with high variability in clinical course. Insufficient stratification according to the aggressiveness at the time of diagnosis causes unnecessary or delayed treatment. Current stratification systems are not effective enough because they are based on clinical, surgical or biochemical parameters, but do not take into account molecular factors driving PCa cancerogenesis. MicroRNAs (miRNAs) are important players in molecular pathogenesis of PCa and could serve as valuable biomarkers for the assessment of disease aggressiveness and its prognosis.

METHODS

In the study, in total, 280 PCa patients were enrolled. The miRNA expression profiles were analyzed in FFPE PCa tissue using the miRCURY LNA miRNA PCR System. The expression levels of candidate miRNAs were further verified by two-level validation using the RT-qPCR method and evaluated in relation to PCa stratification reflecting the disease aggressiveness.

RESULTS

MiRNA profiling revealed 172 miRNAs dysregulated between aggressive (ISUP 3-5) and indolent PCa (ISUP 1) (p < 0.05). In the training and validation cohort, miR-15b-5p and miR-106b-5p were confirmed to be significantly upregulated in tissue of aggressive PCa when their level was associated with disease aggressiveness. Furthermore, we established a prognostic score combining the level of miR-15b-5p and miR-106b-5p with serum PSA level, which discriminated indolent PCa from an aggressive form with even higher analytical parameters (AUC being 0.9338 in the training set and 0.8014 in the validation set, respectively). The score was also associated with 5-year biochemical progression-free survival (bPFS) of PCa patients.

CONCLUSIONS

We identified a miRNA expression pattern associated with disease aggressiveness in prostate cancer patients. These miRNAs may be of biological interest as the focus can be also set on their specific role within the molecular pathology and the molecular mechanism that underlies the aggressivity of prostate cancer.

An miRNA Signature Predicts Grading of Pancreatic Neuroendocrine Neoplasms

BACKGROUND/AIM

Grading pancreatic neuroendocrine neoplasms (PNENs) via mitotic rate and Ki-67 index score is complicated by interobserver variability. Differentially expressed miRNAs (DEMs) are useful for predicting tumour progression and may be useful for grading.

PATIENTS AND METHODS

Twelve PNENs were selected. Four patients had grade (G) 1 pancreatic neuroendocrine tumours (PNETs); 4 had G2 PNETs; and 4 had G3 PNENs (2 PNETs and 2 pancreatic neuroendocrine carcinomas). Samples were profiled using the miRNA NanoString Assay.

RESULTS

There were 6 statistically significant DEMs between different grades of PNENs. MiR1285-5p was the sole miRNA differentially expressed (p=0.03) between G1 and G2 PNETs. Six statistically significant DEMs (miR135a-5p, miR200a-3p, miR3151-5p, miR-345-5p, miR548d-5p and miR9-5p) (p<0.05) were identified between G1 PNETs and G3 PNENs. Finally, 5 DEMs (miR155-5p, miR15b-5p, miR222-3p, miR548d-5p and miR9-5p) (p<0.05) were identified between G2 PNETs and G3 PNENs.

CONCLUSION

The identified miRNA candidates are concordant with their patterns of dysregulation in other tumour types. The reliability of these DEMs as discriminators of PNEN grades support further investigations using larger patient populations.

MiR-15b-5p inhibits castration-resistant growth of prostate cancer cells by targeting the muscarinic cholinergic receptor CHRM3

Cholinergic receptor muscarinic 3 (CHRM3)-mediated focal adhesion kinase/YES-associated protein (YAP) signalling is essential for the growth of castration-resistant prostate cancer (CRPC) cells. Here, we evaluated the molecular mechanisms through which CHRM3 overexpression facilitates castration-resistant growth. Small RNA sequencing combined with in silico analyses revealed that CHRM3 was a putative target of miR-15b-5p. Notably, androgen deprivation suppressed miR-15b-5p expression and increased CHRM3 expression. Moreover, miR-15b-5p bound directly to CHRM3 and inhibited YAP activation induced by CHRM3 stimulation. Furthermore, miR-15b-5p abolished the growth of CRPC cells induced by CHRM3 stimulation. We conclude that the miR-15b-5p/CHRM3/YAP signalling axis promotes the castration-resistant growth of prostate cancer.

Circ-ABCC4 contributes to prostate cancer progression and radioresistance by mediating miR-1253/SOX4 cascade

Circular RNAs (circRNAs) exert pivotal functions in many malignancies. However, the roles of circ-ABCC4 in prostate cancer (PCa) radioresistance and progression remain largely unclear. Cell viability, proliferation, apoptosis, invasion, and radioresistance were evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, 5-ethynyl-2'-deoxyuridine, flow cytometry, transwell invasion, and colony formation assays. Tumor xenograft experiment was conducted to assess circ-ABCC4 role in xenograft growth in vivo. Dual-luciferase reporter assay was implemented to test the target relation of microRNA-1253 (miR-1253) and circ-ABCC4 or SRY-box transcription factor 4 (SOX4). Circ-ABCC4 enrichment was prominently raised in PCa tissue specimens and cells. Circ-ABCC4 depletion blocked PCa cell viability, proliferation, invasion, and radioresistance and triggered apoptosis. Circ-ABCC4 silencing aggravated irradiation-induced inhibitory effect on xenografts growth. miR-1253 was a downstream molecule of circ-ABCC4, and circ-ABCC4 depletion-mediated anti-cancer impacts in PCa cells were partly counteracted by decreasing miR-1253 abundance. miR-1253 targeted SOX4 mRNA, and miR-1253 blocked PCa cell malignant phenotypes partly by targeting SOX4. Circ-ABCC4 could enhance SOX4 abundance by absorbing miR-1253. Circ-ABCC4 exerted a pro-tumor activity by facilitating PCa cell viability, proliferation, invasion, and radioresistance and suppressing apoptosis.

The histidine phosphatase LHPP: an emerging player in cancer

Cancers continue to have high incidence and mortality rates worldwide. Therefore, cancer control remains the main public health goal. Growing research evidence suggests that phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP) plays an important role in inhibiting tumor cell progression. It has been reported in the literature that LHPP is expressed at low levels in tumor tissues and cells and that patients with low LHPP expression have a poorer prognosis. Functional studies have shown that LHPP can inhibit tumor cell proliferation, metastasis, and apoptosis by affecting different target genes. In addition, researchers have used iDPP nanoparticles to deliver LHPP plasmids to treat tumors, demonstrating the great potential of LHPP plasmids for cancer therapy. In our review, we highlight the biological functions and important downstream target genes of LHPP in tumors, providing a theoretical basis for the treatment of human cancers. Although not thoroughly studied in terms of tumor mechanisms, LHPP still represents a promising and effective anticancer drug target.

A Comprehensive Review on Function of miR-15b-5p in Malignant and Non-Malignant Disorders

miR-15b-5p is encoded by MIR15B gene. This gene is located on cytogenetic band 3q25.33. This miRNA participates in the pathogenesis of several cancers as well as non-malignant conditions, such as abdominal aortic aneurysm, Alzheimer’s and Parkinson’s diseases, cerebral ischemia reperfusion injury, coronary artery disease, dexamethasone induced steatosis, diabetic complications and doxorubicin-induced cardiotoxicity. In malignant conditions, both oncogenic and tumor suppressor impacts have been described for miR-15b-5p. Dysregulation of miR-15b-5p in clinical samples has been associated with poor outcome in different kinds of cancers. In this review, we discuss the role of miR-15b-5p in malignant and non-malignant conditions.

Tumor-derived exosomal microRNA-15b-5p augments laryngeal cancer by targeting TXNIP

Tumor-derived exosomes (EXO) are information carriers of microRNA (miR) in cancer development. Here, we explored the synergism of tumor-derived EXO and miR-15b-5p in laryngeal cancer (LCa). miR-15b-5p and thioredoxin-interacting protein (TXNIP) levels were firstly measured in clinical LCa tissues. The association between miR-15b-5p and TXNIP was determined. miR-15b-5p mimic was transfected into HEP-2 cells, and the corresponding exosomes were extracted. miR-15b-5p mimic-modified EXO were co-cultured with HEP-2 cells, and TXNIP low expression/high expression vector was transfected into HEP-2 cells Finally, cell growth was observed in vitro and in vivo. miR-15b-5p level was high while TXNIP level was low in LCa, and miR-15b-5p negatively modulated TXNIP expression. HEP-2 cells-derived EXO or inhibition of TXNIP enhanced HEP-2 cell growth in vitro and in vivo. Up-regulated miR-15b-5p further strengthened the pro-tumor effect of EXO, but this effect was reversed by overexpression of TXNIP. Overall, tumor-derived exosomal miR-15b-5p augments LCa through targeting down-regulation of TXNIP.

Identification of Candidate lncRNA and Pseudogene Biomarkers Associated with Carbon-Nanotube-Induced Malignant Transformation of Lung Cells and Prediction of Potential Preventive Drugs

Mounting evidence has linked carbon nanotube (CNT) exposure with malignant transformation of lungs. Long non-coding RNAs (lncRNAs) and pseudogenes are important regulators to mediate the pathogenesis of diseases, representing potential biomarkers for surveillance of lung carcinogenesis in workers exposed to CNTs and possible targets to develop preventive strategies. The aim of this study was to screen crucial lncRNAs and pseudogenes and predict preventive drugs. GSE41178 (small airway epithelial cells exposed to single- or multi-walled CNTs or dispersant control) and GSE56104 (lung epithelial cells exposed to single-walled CNTs or dispersant control) datasets were downloaded from the Gene Expression Omnibus database. Weighted correlation network analysis was performed for these two datasets, and the turquoise module was preserved and associated with CNT-induced malignant phenotypes. In total, 24 lncRNAs and 112 pseudogenes in this module were identified as differentially expressed in CNT-exposed cells compared with controls. Four lncRNAs (MEG3, ARHGAP5-AS1, LINC00174 and PVT1) and five pseudogenes (MT1JP, MT1L, RPL23AP64, ZNF826P and TMEM198B) were predicted to function by competing endogenous RNA (MEG3/RPL23AP64-hsa-miR-942-5p-CPEB2/PHF21A/BAMBI; ZNF826P-hsa-miR-23a-3p-SYNGAP1, TMEM198B-hsa-miR-15b-5p-SYNGAP1/CLU; PVT1-hsa-miR-423-5p-PSME3) or co-expression (MEG3/MT1L/ZNF826P/MT1JP-ATM; ARHGAP5-AS1-TMED10, LINC00174-NEDD4L, ARHGAP5-AS1/PVT1-NIP7; MT1L/MT1JP-SYNGAP1; MT1L/MT1JP-CLU) mechanisms. The expression levels and prognosis of all genes in the above interaction pairs were validated using lung cancer patient samples. The receiver operating characteristic curve analysis showed the combination of four lncRNAs, five pseudogenes or lncRNAs + pseudogenes were all effective for predicting lung cancer (accuracy >0.8). The comparative toxicogenomics database suggested schizandrin A, folic acid, zinc or gamma-linolenic acid may be preventive drugs by reversing the expression levels of lncRNAs or pseudogenes. In conclusion, this study highlights lncRNAs and pseudogenes as candidate diagnostic biomarkers and drug targets for CNT-induced lung cancer.

The lncRNA NEAT1/miRNA-766-5p/E2F3 Regulatory Axis Promotes Prostate Cancer Progression

Background

Prostate cancer (PCa) is one of the most common malignancies in men. Increasing evidence has demonstrated that dysregulation of long noncoding RNAs (lncRNAs) is closely related to carcinogenesis and cancer progression. lncRNA NEAT1 has recently been identified as a carcinogenic regulator of multiple cancers; however, the role of NEAT1 on PCa is still poorly understood.

Methods

Kaplan–Meier was conducted to determine the overall survival rate in PCa patients with aberrant NEAT1 levels. qRT-PCR analysis was performed to detect expressions of NEAT1 and miR-766-5p in tissues and cells. In addition, CCK-8, colony formation, flow cytometry analysis, wound healing, and transwell assay were conducted to determine cell proliferation, cell arrest, apoptosis, migration, and invasion. The western blot assay was utilized to determine E2F3 and cell growth-related proteins. The relationship between NEAT1 and miR-766-5p or miR-766-5p and E2F3 was verified by correlation analysis and dual-luciferase reporter assay.

Results

Here, we find that NEAT1 is overexpressed in PCa tissues and cell lines. Besides, silencing of NEAT1 inhibits cell proliferation, invasion, and migration and promotes cell apoptosis and cell cycle arrest. Further mechanistic studies find that NEAT1 sponges miR-766-5p, and miRNA-766-5p is negatively correlated with the expression of NEAT1. In addition, the functional experiment shows that upregulation of miRNA-766-5p inhibits PCa proliferation, migration, and invasion. Furthermore, E2F transcription factor 3 (E2F3) is testified to be the downstream target gene of miRNA-766-5p. Finally, the rescue experiment revealed that miRNA-766-5p inhibition largely restores NEAT1 downregulation-mediated function on PCa progression, while E2F3 knockdown partly removes the effects of miRNA-766-5p inhibitor.

Conclusions

In conclusion, NEAT1 facilitates PCa progression by targeting the miRNA-766-5p/E2F3 axis.

Treatment of Human Glioblastoma U251 Cells with Sulforaphane and a Peptide Nucleic Acid (PNA) Targeting miR-15b-5p: Synergistic Effects on Induction of Apoptosis

Glioblastoma multiforme (GBM) is a lethal malignant tumor accounting for 42% of the tumors of the central nervous system, the median survival being 15 months. At present, no curative treatment is available for GBM and new drugs and therapeutic protocols are urgently needed. In this context, combined therapy appears to be a very interesting approach. The isothiocyanate sulforaphane (SFN) has been previously shown to induce apoptosis and inhibit the growth and invasion of GBM cells. On the other hand, the microRNA miR-15b is involved in invasiveness and proliferation in GBM and its inhibition is associated with the induction of apoptosis. On the basis of these observations, the objective of the present study was to determine whether a combined treatment using SFN and a peptide nucleic acid interfering with miR-15b-5p (PNA-a15b) might be proposed for increasing the pro-apoptotic effects of the single agents. To verify this hypothesis, we have treated GMB U251 cells with SFN alone, PNA-a15b alone or their combination. The cell viability, apoptosis and combination index were, respectively, analyzed by calcein staining, annexin-V and caspase-3/7 assays, and RT-qPCR for genes involved in apoptosis. The efficacy of the PNA-a15b determined the miR-15b-5p content analyzed by RT-qPCR. The results obtained indicate that SFN and PNA-a15b synergistically act in inducing the apoptosis of U251 cells. Therefore, the PNA-a15b might be proposed in a “combo-therapy” associated with SFN. Overall, this study suggests the feasibility of using combined treatments based on PNAs targeting miRNA involved in GBM and nutraceuticals able to stimulate apoptosis.

Tissue expression of MMP-9, TIMP-1, RECK, and miR338-3p in prostate gland: can it predict cancer?

Prostate cancer is the most frequent malignancy affecting men worldwide. Due to the low sensitivity and specificity of the prostate-specific antigen test and the digital rectal exam as screening modalities, several alternatives are being studied. This study aimed to evaluate the application of MMP-9 and its regulators (TIMP-1, RECK, and miR-338-3p) as diagnostic and prognostic indicators of prostate cancer. A total of 134 randomly selected patients under investigation for prostate cancer submitted to a transrectal ultrasound-guided prostate biopsy were enrolled in the study; of these, 61 were positive for the disease (cases), and 73 were negative (control group). The tissue samples were further analyzed by gene and miR-338-3p expression analysis using qRT-PCR (one randomly selected fragment of each patient). Approximately 58% of the patients with prostate cancer presented MMP9 upregulation, while 73%, 65%, and 69% downregulated IMP-1, RECK, and miR-338-3p, respectively. MiR-338-3p was expressed at lower levels in patients with PSA concentrations exceeding 20 ng/mL (p=0.045) and abnormal DRE (p=0.006), while the RECK was more expressed in patients with abnormal DRE (p=0.01). We found that most patients with prostate cancer overexpressed MMP-9; on the other hand, most of them underexpressed TIMP-1, RECK, and miR-338-3p. MiR-338-3p presented as a possible predictor of poor prognosis. Further studies are warranted to evaluate these biomarkers as prognosis factors better.

hsa-miR-15b-5p regulates the proliferation and apoptosis of human vascular smooth muscle cells by targeting the ACSS2/PTGS2 axis

A previous bioinformatic analysis from our group predicted that the interaction of microRNA (miRNA/miR)-15b with the acyl-CoA synthetase short chain family member 2 (ACSS2) gene was important for the development of abdominal aortic aneurysm (AAA). Apoptosis of aortic vascular smooth muscle cells (VSMCs) is a pathological feature of AAA. The present study aimed to explain the roles of miR-15b/ACSS2 in AAA by exploring their effects on the proliferation and apoptosis of aortic VSMCs. Human aortic VSMCs (T/G HA-VSMC cell line) were divided into six groups and were transfected with miR-15b-5p mimics, mimic negative control (NC), miR-15b-5p inhibitors, inhibitor NC, miR-15b-5p mimics+pcDNA3.1 and miR-15b-5p mimics+ACSS2-overexpessing vector. CCK-8 assay was used to determine cell proliferation. Annexin V-FITC/PI staining and flow cytometry assays were used to measure cell apoptosis. Dual-luciferase reporter assays were used to confirm the targeted relationship between miR-15b-5p and ACSS2. Reverse transcription-quantitative PCR and/or western blotting were used to examine the expression levels of miR-15b-5p, ACSS2 and prostaglandin-endoperoxide synthase 2 (PTGS2). Following transfection of T/G HA-VSMCs with mimics and inhibitors to respectively upregulate and downregulate miR-15b-5p, the results demonstrated that overexpression of miR-15b-5p inhibited cell proliferation and promoted cell apoptosis; silencing of miR-15b-5p obtained the opposite results. ACSS2 may be a direct target of miR-15b-5p, since the luciferase activity of a ACSS2 wild-type vector, but not that of a ACSS2 mutant reporter, was significantly inhibited by miR-15b-5p mimics compared with controls. Additionally, the expression levels of ACSS2 and its downstream gene PTGS2 were significantly reduced or increased following transfection with miR-15b-5p mimics or inhibitors, respectively. Furthermore, overexpression of ACSS2 reversed the antiproliferative and proapoptotic effects of miR-15b-5p mimics by blocking the production of PTGS2 protein. In conclusion, miR-15b-5p may promote the apoptosis and inhibit the proliferation of aortic VSMCs via targeting the ACSS2/PTGS2 axis. The present study provided preliminary evidence indicating that the miR-15b-5p/ACSS2/PTGS2 axis may be a potential target for the treatment of AAA.

Long non-coding RNA AFAP1-AS1 facilitates prostate cancer progression by regulating miR-15b/IGF1R axis

BACKGROUND

Prostate cancer (PCa) is a commonly diagnosed malignant cancer and is the second highest cause of cancer related death in men worldwide. Enzalutamide is the second-generation inhibitor of androgen receptor signaling and is the fundamental drug for the treatment of advanced PCa. However, the disease will eventually progress to metastatic castration-resistant prostate cancer (CRPC) and aggressive neuroendocrine prostate cancer (NEPC) because of androgen-deprivation therapy (ADT) resistance. The aim of the study was to investigate the role of long non-coding RNA (lncRNA) AFAP1-AS1 in ADT resistance.

METHODS

Quantitative real-time PCR analysis (qPCR) was used to assess the expression of AFAP1-AS1 in PCa cell lines and tissues. Cell proliferation and invasion were assessed after AFAP1-AS1 knockdown using Cell Counting Kit (CCK)-8 and Transwell assay, respectively. A dual-luciferase reporter gene assay was carried out to validate the regulatory relationship among AFAP1-AS1, microRNA (miR)-15b, and insulin-like growth factor1 receptor (IGF1R).

RESULTS

AFAP1-AS1 level was markedly increased in castration-resistant C4-2 cells and NE-like cells (PC3, DU145, and NCI-H660), compared with androgen-sensitive LNCaP cells. Enzalutamide treatment increased the expression of AFAP1-AS1 in vitro and in vivo. Functionally, AFAP1-AS1 knockdown repressed tumor cell proliferation and invasion. Mechanistically, AFAP1-AS1 functioned as an oncogene in PCa through binding to miR-15b and destroying its tumor suppressor function. Finally, we identified that AFAP1-AS1 up-regulated IGF1R expression by competitively binding to miR-15b to de-repress IGF1R.

CONCLUSION

AFAP1-AS1 facilitates PCa progression by regulating miR-15b/IGF1R axis, indicating that AFAP1-AS1 may serve as a diagnostic biomarker and therapeutic target for PCa.

miR-182 modulates cell proliferation and invasion in prostate cancer via targeting ST6GALNAC5

Altered expression of miR-182 has been observed in various types of human cancer. The purpose of this study was to investigate the expression of miR-182 and its role in prostate cancer (PCa). Expression of miR-182 and ST6GALNAC5 in tumor tissues and the Du145 PCa cell line was analyzed. Cell proliferation assay, colony formation assay, transwell assay, and wound healing assay were performed. The impact of miR-182 on tumor growth was investigated using a xenograft model. The results indicated that expression of miR-182 was higher in PCa tissues and cell lines, while ST6GALNAC5 was decreased. Downregulating miR-182 significantly inhibited the capacities of proliferation and invasion of PC3 and Du145 cells. ST6GALNAC5 was demonstrated to be a target of miR-182 by luciferase assay, and western blot results indicated PI3K/Akt pathway was involved in miR-182 associated effects on PC3 and Du145 cells. The animal experiment suggested that knockdown of miR-182 inhibited tumor growth. Our study proved that miR-182 participated in the proliferation and invasion of PCa cells via mediating expression of ST6GALNAC5 and established a miR-182/ST6GALNAC5/PI3K/AKT axis in regulation of tumor progression. Our investigation provided a basis for further exploration of the application of miR-182 or ST6GALNAC5-associated therapies for PCa patients.

An Insight on the Role of Altered Function and Expression of Exosomes and MicroRNAs in Female Reproductive Diseases

Exosomes are small bilayer-lipid membrane vesicles secreted by living cells that are able to transfer regulatory molecules and genetic information from one cell to another. These vesicles are enriched with several nucleic acids including mRNAs, microRNAs (miRNAs), other non-coding RNAs, as well as proteins and lipids. Alterations in the exosomal content and functions are observed in numerous reproductive diseases in both animals and human cases. MicroRNAs, a class of small endogenous RNA molecules, can negatively regulate gene expression at the post-transcription level. Aberrant microRNA expression has been reported in multiple human reproductive diseases such as polycystic ovary syndrome, preeclampsia, uterine leiomyomata, ovarian cancer, endometriosis, and Asherman's syndrome. This study focuses to review recent research on alterations of microRNA expression and the role of exosomes in female reproductive diseases. It has been demonstrated that exosomes may be a potential therapeutic approach in various female reproductive diseases. In addition, changes in expression of microRNAs act as molecular biomarkers for diagnosis of several reproductive diseases in women, and regulation of their expression can potentially reduce infertility.

LncRNA MEG8 promotes NSCLC progression by modulating the miR-15a-5p-miR-15b-5p/PSAT1 axis

BACKGROUND

Non-small cell lung cancer (NSCLC) is the most common tumor with severe morbidity and high mortality. Long non-coding RNAs (lncRNAs) as crucial regulators participate in multiple cancer progressions. However, the role of lncRNA MEG8 in the development of NSCLC remains unclear. Here, we aimed to investigate the effect of lncRNA MEG8 on the progression of NSCLC and the underlying mechanism.

METHODS

Cell proliferation was analyzed by EdU assays. The impacts of lncRNA MEG8, miR-15a-5p, and miR-15b-5p on cell invasion and migration of NSCLC were assessed by transwell assay. The luciferase reporter gene assay was performed using the Dual-luciferase Reporter Assay System. The effect of lncRNA MEG8, miR-15a-5p, and miR-15b-5p on tumor growth was evaluated in nude mice of Balb/c in vivo.

RESULTS

We revealed that the expression levels of MEG8 were elevated in the NSCLC patient tissues compared to that in adjacent normal tissues. The expression of MEG8 was negatively relative to that of miR-15a-5p and miR-15b-5p in the NSCLC patient tissues. The expression of MEG8 was upregulated, while miR-15a-5p and miR-15b-5p were downregulated in NSCLC cell lines. The depletion of MEG8 inhibited NSCLC cell proliferation, migration, and invasion in vitro. MEG8 contributed to NSCLC progression by targeting miR-15a-5p/miR-15b-5p in vitro. LncRNA MEG8 contributes to tumor growth of NSCLC via the miR-15a/b-5p/PSAT1 axis in vivo. Thus, we concluded that lncRNA MEG8 promotes NSCLC progression by modulating the miR-15a/b-5p/PSAT1 axis.

CONCLUSIONS

Our findings demonstrated that lncRNA MEG8 plays a critical role in NSCLC development. LncRNA MEG8, miR-15a-5p, miR-15b-5p, and PSAT1 may serve as potential targets for NSCLC therapy.

SNHG16 knockdown inhibits tumorigenicity of neuroblastoma in children via miR-15b-5p/PRPS1 axis

Neuroblastoma is an important problem in children. Long noncoding RNAs (lncRNAs) exhibit important roles in tumorigenicity of neuroblastoma. However, the role and mechanism of lncRNA small nucleolar RNA host gene 16 (SNHG16) in neuroblastoma tumorigenicity remain poorly understood. Forty-six neuroblastoma samples and 28 normal tissues were harvested. The levels of SNHG16, microRNA-15b-5p (miR-15b-5p), and phosphoribosyl pyrophosphate synthetase 1 (PRPS1) were detected via quantitative reverse transcription PCR or western blot. Cell proliferation as well as cycle distribution were measured via 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide or flow cytometry. Cell metastasis was investigated via epithelial-mesenchymal transition or transwell assay. The target relationship of miR-15b-5p and SNHG16 or PRPS1 was explored via starBase and dual-luciferase reporter assay. The role of SNHG16 in neuroblastoma in vivo was analyzed using a xenograft model. We found SNHG16 and PRPS1 levels were increased in neuroblastoma tissues and cells. SNHG16 knockdown inhibited cell proliferation, increased the cell cycle distribution at G0/G1 phase, and decreased the cells at S phase. SNHG16 overexpression caused an opposite effect. SNHG16 silence suppressed neuroblastoma cell metastasis. PRPS1 knockdown constrained cell proliferation and metastasis and regulated cell cycle distribution. miR-15b-5p was sponged by SNHG16 and directly targeted PRPS1. miR-15b-5p knockdown or PRPS1 overexpression mitigated the influence of SNHG16 silence on cell cycle, proliferation, and metastasis. SNHG16 knockdown reduced xenograft tumor growth. In conclusion, SNHG16 downregulation suppressed neuroblastoma tumorigenicity by regulating cell cycle, proliferation, and metastasis via miR-15b-5p/PRPS1 axis.

Inhibition of microRNA-15b-5p Attenuates the Progression of Oral Squamous Cell Carcinoma via Modulating the PTPN4/STAT3 Axis

BACKGROUND

Emerging evidence has demonstrated the important functions of microRNAs (miRNAs) in human malignancies. This study focuses on the function of miR-15b-5p on the oral squamous cell carcinoma (OSCC) progression and the molecules involved.

METHODS

Tumor and the paracancerous tissues were obtained from OSCC patients. Differentially expressed miRNAs between the tumor and normal tissues were screened out. miR-15b-5p expression in tumors and acquired cells was determined, and its correlation with patient survival was analyzed. Knockdown of miR-15b-5p was introduced in SCC-4 and CAL-27 cells to explore its role in cell growth and metastasis. Binding relationship between miR-15b-5p and PTPN4 was validated, and altered expression of PTPN4 was introduced in cells to explore its function in OSCC development. Xenograft tumors were induced in nude mice for in vivo experiments.

RESULTS

miR-15b-5p was abundantly expressed in OSCC tumors and cells and linked to poor survival in patients. Silencing of miR-15b-5p suppressed proliferation, migration, and invasion and triggered apoptosis in SCC-4 and CAL-27 cells. miR-15b-5p targeted PTPN4. Further silencing of PTPN4 blocked the inhibiting functions of miR-15b-5p inhibitor in OSCC cell growth. The in vitro results were reproduced in vivo, where inhibition of miR-15b-5p led to a decline in tumor growth and metastasis in nude mice. PTPN4 was found as a negative mediator of the STAT3 pathway.

CONCLUSION

This study evidenced that miR-15b-5p possibly promotes OSCC development through binding to PTPN4 and the following STAT3 signaling activation. miR-15b-5p may be a potential therapeutic target for OSCC.

The Significance of Circular RNA DDX17 in Prostate Cancer

Circular RNA DDX17 (circDDX17) has been demonstrated as a tumor suppressor in colorectal cancer. However, mechanisms underlying circDDX17 effects in cases of prostate cancer (PCa) are not well understood. Thus, herein, we determined measures of circDDX17 expression by use of the TCGA database. Expression of circDDX17 in prostate cancer-afflicted tissue samples was determined by qRT-PCR. Functionally, circDDX17 induced remarkable inhibition of cell colonizing ability, invasion, and epithelial-mesenchymal transition (EMT) progression in vitro. Mechanistically, dual-luciferase reporter assays, RNA immunoprecipitation, and RNA pull-down experiments helped verify interactions between circDDX17 and miR-346. Low expression of circDDX17 occurred in TCGA PCa samples. Furthermore, circDDX17 expression was downregulated significantly in PCa. These results suggested that circDDX17 suppressed PC cell mobility, proliferation, and invasion. Mechanistic experiments indicated that circDDX17 might serve as a ceRNA of miR-346 to relieve repressive effects of miR-346 upon phospholysine phosphohistidine inorganic pyrophosphate phosphatase (LHPP). LHPP expression itself was downregulated in TCGA PCa samples. Overall, our findings indicated that the circDDX17/miR-346/LHPP pathway inhibited the progression of prostate cancer and that circDDX17 may be a new potential therapeutic or diagnostic target for treating and diagnosing prostate cancer. As our study also demonstrated for the first time that LHPP might act as an anticancer gene in prostate cancer, the findings could have wide-ranging implications for the treatment of this affliction.

MicroRNA‑15b‑5p exerts its tumor repressive role via targeting GDI2: A novel insight into the pathogenesis of thyroid carcinoma

Thyroid carcinoma (THCA) is a malignant tumor of the endocrine system. Previous studies have revealed the vital roles of microRNAs (miRNAs/miRs) in THCA procession. The present study aimed to explore the effects of miR-15b-5p on the progression of THCA and its targeting mechanism. The data of THCA and healthy samples were firstly collected from starbase2.0 and used to analyze the relationship of miR-15b-5p with THCA. Dual-luciferase assay was performed to detect the direct interaction between miR-15b-5p and the predicted target gene GDP dissociation inhibitor 2 (GDI2). The effects of miR-15b-5p and GDI2 on the overall survival of patients with THCA were analyzed using Kaplan-Meier analysis with log rank test. Cell Counting Kit-8 and Transwell assays were conducted to assess the impacts of miR-15b-5p and GDI2 on the proliferation and invasion of THCA cells. Reverse transcription-quantitative PCR and western blot analyses were performed to analyze the expression levels of the related miRNAs and proteins, respectively. miR-15b-5p was found to be downregulated both in THCA tissues and cells, and the low expression of miR-15b-5p was associated with the short overall survival time of patients. Moreover, the upregulation or downregulation of miR-15b-5p could inhibit or enhance the proliferation and invasion of THCA cells, respectively. miR-15b-5p reduced the protein expression levels of matrix metalloproteinase (MMP)2 and MMP9, which were related to cell invasion. Furthermore, GDI2, which was enhanced in THCA and related to the poor prognosis of patients with THCA, was identified as the target gene of miR-15b-5p and negatively regulated by miR-15b-5p. Additional experiments demonstrated that GDI2 overexpression could significantly reduce the antitumor effect of miR-15b-5p and its inhibitory action on the expression levels of MMP2 and MMP9. Thus, the results indicated a potential tumor suppressive role of miR-15b-5p in THCA, which was mainly exerted by targeting GDI2 and modulating MMP2 and MMP9. These findings will increase the understanding on the pathogenesis of THCA and provide novel candidates for THCA therapy.

LNC473 Regulating APAF1 IRES-Dependent Translation via Competitive Sponging miR574 and miR15b: Implications in Colorectal Cancer

A growing number of studies have focused on the involvement of non-coding RNAs (ncRNAs) in the internal ribosome entry site (IRES)-mediated translation in tumorigenesis; however, the underlying mechanisms in colorectal cancer (CRC) remain elusive. In this study, we show that LINC00473 (LNC473) exerted its functions as a tumor suppressor in promoting apoptotic protease-activating factor 1 (APAF1) IRES activity through competitively sponging miR574-5p and miR15b-5p in CRC initiation and pathogenesis. Specifically, LNC473 and its downstream target APAF1 were significantly downregulated accompanied by upregulated miR574-5p and miR15b-5p in CRC cells and tissues, which had a significant prognostic impact on clinical outcomes in our CRC cohort (n = 157). Furthermore, ectopic LNC473 significantly sponged endogenous miR574-5p or miR15b-5p and thereby inhibited cell proliferation and colony formation capacity, and it accelerated cell apoptosis through activating the APAF1-CASP9-CASP3 pathway. Notably, LNC473 overexpression resulted in dramatic promotion of APAF1 IRES activity and translation, whereas rescue experiments confirmed the recovery by the existence of LNC473 and miR574/15b-5p. Mechanistically, LNC473 overexpression promoted IRES binding domain exposure and removed the constraints controlling from miR574-5p and miR15b-5p, and subsequently enhanced IRES-mediated APAF1 expression in vitro and in vivo. Therefore, our results uncover a novel LNC473-miR574/miR15b-APAF1 signaling axis, which provides new targets and crosstalk regulation mechanism for CRC prevention and treatment.

The Role of miRNA and Related Pathways in Pathophysiology of Uterine Fibroids-From Bench to Bedside

Uterine fibroids (UFs) are the most common benign tumors of the female genital tract. Their prevalence usually is estimated at 30-40%, but may reach up to 70-80% in predisposed groups of women. UFs may cause various clinical issues which might constitute the major reason of the overall deterioration of the quality of life. The mechanisms leading to UFs formation and growth still remain poorly understood. The transformation of smooth muscle cells of the uterus into abnormal, immortal cells, capable of clonal division, is thought to be a starting point of all pathways leading to UF formation. Micro-ribonucleic acids (miRNAs) are non-coding single-stranded RNAs about 22 nucleotides in length, that regulate gene expression. One of recent advances in this field is the comprehension of the role of miRNAs in tumorigenesis. Alterations in the levels of miRNAs are related to the formation and growth of several tumors which show a distinct miRNA signature. The aim of this review is to summarize the current data about the role of miRNAs in the pathophysiology of UFs. We also discuss future directions in the miRNA research area with an emphasis on novel diagnostic opportunities or patient-tailored therapies. In our opinion data concerning the regulation of miRNA and its gene targets in the UFs are still insufficient in comparison with gynecological malignancies. The potential translational use of miRNA and derived technologies in the clinical care is at the early phase and needs far more evidence. However, it is one of the main areas of interest for the future as the use of miRNAs in the diagnostics and treatment of UFs is a new and exciting opportunity.

Analysis of the inhibiting activity of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) on matrix metalloproteinases

Matrix metalloproteinases (MMPs) occur in 23 human paralogues with key functions in physiology, and their activity is controlled by protein inhibitors. Reversion-inducing cysteine-rich protein with Kazal motifs (RECK), which is essential for embryogenesis and tumour suppression, has been reported to inhibit MMPs. Here, we developed eukaryotic and bacterial expression systems for different RECK variants and analysed their inhibitory capacity against representative MMPs in vitro. We could not detect any significant inhibition. Instead, we found that partially purified RECK from the conditioned medium of transfected Expi293F cells but not that of ExpiCHO-S or Drosophila Schneider cells contained a contaminant with proteolytic activity. The contaminant was removed through treatment with a small-molecule serine peptidase inhibitor and additional chromatographic purification. A tantamount contaminant was further detected in an equivalent expression system of the N-terminal fragment of the proteoglycan testican 3, but not in those of two other proteins. These results indicate that previous reports of inhibitory activity of recombinant RECK on MMPs, which were performed with partially purified samples, were probably masked by a coeluting contaminant present in the supernatant of HEK293-derived cells. Thus, RECK is probably not a direct inhibitor of MMP catalytic activity but may still regulate MMPs through other mechanisms.

miR-15b enhances the proliferation and migration of lung adenocarcinoma by targeting BCL2

Background

Lung adenocarcinoma (LUAD) is a subtype of lung cancer (LC), which is the most common tumor worldwide. Accumulating evidence has elucidated an important role of microRNAs (miRNAs) in mediating the development and progression of several tumors. The purpose of this study was to explore the role and underlying mechanism of miR‐15b in LUAD.

Methods

CCK‐8 and Transwell assays were conducted to measure the capacities of cell viability and migration in SPC‐A1 cells. Luciferase assay was utilized to verifymiR‐15b direct binding to BCL2 mRNA 3′‐UTR.

Results

We determined that miR‐15b was overexpressed in LUAD and miR‐15b overexpression predicted a significantly worse outcome in patients with LUAD. miR‐15b improved LUAD growth in vitro and vivo. miR‐15b enhanced cell migration and epithelial–mesenchymal transition (EMT) in LUAD. miR‐15b promoted cell viability, migration and EMT through inhibiting BCL2 expression by targeting to its mRNA 3′‐UTR. BCL2 reversed functions of miR‐15b on promoting cell proliferation, migration and EMT in SPC‐A1 cells.

Conclusions

miR‐15b promoted cell viability, migration and EMT by targeting BCL2 in LUAD. The newly identified miR‐15b/BCL2 axis provides a novel insight into the pathogenesis of LUAD.

Exosomal miR-182 regulates the effect of RECK on gallbladder cancer

BACKGROUND

As the most common biliary malignancy, gallbladder cancer (GC) is an elderly-biased disease. Although extensive studies have elucidated the molecular mechanism of microRNA 182 (miR-182) and reversion-inducing-cysteine-rich protein with kazal motifs (RECK) in various cancers, the specific role of exosomal miR-182 and RECK in GC remains poorly understood.

AIM

To explore the relationship between exosomal miR-182/RECK and metastasis of GC.

METHODS

Paired GC and adjacent normal tissues were collected from 78 patients. Quantitative polymerase chain reaction was employed to detect miR-182 and exosomal miR-182 expression, and Western blotting was conducted to determine RECK expression. In addition, the effects of exosomal miR-182/RECK on the biological function of human GC cells were observed. Moreover, the double luciferase reporter gene assay was applied to validate the targeting relationship between miR-182 and RECK.

RESULTS

Compared with normal gallbladder epithelial cells, miR-182 was highly expressed in GC cells, while RECK had low expression. Exosomal miR-182 could be absorbed and transferred by cells. Exosomal miR-182 inhibited RECK expression and promoted the migration and invasion of GC cells.

CONCLUSION

Exosomal miR-182 can significantly promote the migration and invasion of GC cells by inhibiting RECK; thus miR-182 can be used as a therapeutic target for GC.

miR-15b-5p Promotes Growth and Metastasis in Breast Cancer by Targeting HPSE2

MicroRNAs (miRNAs) can participate in many behaviors of various tumors. Prior studies have reported that miR-15b-5p in different tumors can either promote or inhibit tumor progression. In breast cancer, the role of miR-15b-5p is unclear. The main objective of this paper is to explore miR-15b-5p effects and their mechanisms in breast cancer using both in vitro and in vivo experiments. This study showed that miR-15b-5p expression was upregulated in breast cancer compared with normal breast tissue and was positively correlated with poor overall survival in patients. Knockdown of miR-15b-5p in MCF-7 and MD-MBA-231 breast cancer cells restrained cell growth and invasiveness and induced apoptosis, whereas overexpression of miR-15b-5p achieved the opposite effects. We next revealed a negative correlation between miR-15b-5p and heparanase-2 (HPSE2) expression in breast cancer. Knockdown of miR-15b-5p significantly increased HPSE2 expression at both mRNA and protein levels in breast cancer cells in vitro. The underlying mechanisms of miR-15-5p in breast cancer were investigated using luciferase activity reporter assay and rescue experiments. In addition, miR-15b-5p knockdown significantly inhibited tumor growth in a xenograft model in mice. In summary, we showed that miR-15b-5p promotes breast cancer cell proliferation, migration, and invasion by directly targeting HPSE2. Accordingly, miR-15b-5p may serve both as a tool for prognosis and as a target for therapy of breast cancer patients.

Long noncoding RNA LINC00662-miR-15b-5p mediated GPR120 dysregulation contributes to osteoarthritis

Previous studies demonstrated that dysregulation of G protein-coupled receptor 120 (GPR120) plays a protective role in osteoarthritis (OA). However, the mechanism underlying how GPR120 is downregulated remains largely unknown. In the present study, we evaluated whether GPR120 is regulated by microRNAs (miRNAs) and long noncoding RNAs (lncRNAs). Our results show that GPR120 was negatively regulated by miR-15b-5p through targeting 3' untranslated region (3'UTR), and that miR-15b-5p was negatively regulated by LINC00662. Further luciferase assay shows that LINC00662-miR-15b-5p signaling pathway contributed the regulation of GPR120 expression. Functionally, the decreased of LINC00662 caused increased miR-15b-5p, thereby leading to decreased GPR120. The decreased GPR120 then contributes to increased expression of inflammatory factors including tumor necrosis factor α (TNF-α), interleukin (IL)-6 and IL-8, cell apoptosis, and decreased apoptosis-related protein levels including cleaved caspase-3, cleaved caspase-9, and Bax in cultured rat chondrocytes. In summary, the present study shows that LINC00662-miR-15b-5p signaling pathway is involved in the regulation of GPR120, thereby contributing to arthritis.

LINC00908 negatively regulates microRNA-483-5p to increase TSPYL5 expression and inhibit the development of prostate cancer

Background

Accumulating evidence has associated aberrant long non-coding RNAs (lncRNAs) with various human cancers. This study aimed to explore the role of LINC00908 in prostate cancer (PCa) and its possible underlying mechanisms.

Methods

Microarray data associated with PCa were obtained from the Gene Expression Omnibus (GEO) to screen the differentially expressed genes or lncRNAs. Then, the expression of LINC00908 in PCa tissues and cell lines was detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The localization of LINC00908 in PCa cells was examined by fluorescence in situ hybridization (FISH). The relationship among LINC00908, microRNA (miR)-483-5p, and TSPYL5 was detected by bioinformatics analysis, dual-luciferase reporter assay, RNA pull-down, RNA binding protein immunoprecipitation (RIP), and FISH assays. Cell biological behaviors were assessed after the expression of LINC00908, miR-483-5p, and TSPYL5 was altered in PCa cells. Lastly, tumor growth in nude mice was evaluated.

Results

Poorly expressed LINC00908 was witnessed in PCa tissues and cells. LINC00908 competitively bound to miR-483-5p to up-regulate the TSPYL5 expression. Overexpression of LINC00908 resulted in reduced PCa cell proliferation, migration and invasion, and promoted apoptosis. Additionally, the suppression on PCa cell proliferation, migration and invasion was induced by up-regulation of TSPYL5 or inhibition of miR-483-5p. In addition, in vivo experiments showed that overexpression of LINC00908 inhibited tumor growth of PCa.

Conclusion

Overall, LINC00908 could competitively bind to miR-483-5p to increase the expression of TSPYL5, thereby inhibiting the progression of PCa. Therefore, LINC00908 may serve as a novel target for the treatment of PCa.

Long Non-Coding RNA MAGI2-AS3 is a New Player with a Tumor Suppressive Role in High Grade Serous Ovarian Carcinoma

High-Grade Serous Ovarian Carcinoma (HGSC) is the most incidental and lethal subtype of epithelial ovarian cancer (EOC) with a high mortality rate of nearly 65%. Recent findings aimed at understanding the pathogenesis of HGSC have attributed its principal source as the Fallopian Tube (FT). To further comprehend the exact mechanism of carcinogenesis, which is still less known, we performed a transcriptome analysis comparing FT and HGSC. Our study aims at exploring new players involved in the development of HGSC from FT, along with their signaling network, and we chose to focus on non-coding RNAs. Non-coding RNAs (ncRNAs) are increasingly observed to be the major regulators of several cellular processes and could have key functions as biological markers, as well as even a therapeutic approach. The most physiologically relevant and significantly dysregulated non-coding RNAs were identified bioinformatically. After analyzing the trend in HGSC and other cancers, MAGI2-AS3 was observed to be an important player in EOC. We assessed its tumor-suppressive role in EOC by means of various assays. Further, we mapped its signaling pathway using its role as a miRNA sponge to predict the miRNAs binding to MAGI2AS3 and showed it experimentally. We conclude that MAGI2-AS3 acts as a tumor suppressor in EOC, specifically in HGSC by sponging miR-15-5p, miR-374a-5p and miR-374b-5p, and altering downstream signaling of certain mRNAs through a ceRNA network.

miR-221-3p and miR-15b-5p promote cell proliferation and invasion by targeting Axin2 in liver cancer

Globally, liver cancer has the third highest mortality rate among all types of cancer due to the invasive and metastatic capacities of liver tumor cells. MicroRNA (miR) is a class of non-coding RNAs that participate in the development of liver cancer. The aim of the present study was to explore the molecular mechanisms by which miR-221-3p and miR-15b-5p promote the proliferation and invasion of liver cancer cells through targeting axis formation inhibitor 2 (Axin2) and to identify suitable targets for the treatment of liver cancer. The expression levels of miR-221-3p and miR-15b-5p were determined in liver cancer tissues and cells by quantitative PCR, and the association between miR-221-3p, miR-15b-5p and Axin2 expression in liver cancer cells was analyzed using cell transfection. The results demonstrated that miR-221-3p and miR-15b-5p levels were upregulated in liver cancer tissues and cell lines, and results from predictive bioinformatic analysis and identification revealed that Axin2 was the common target gene of miR-221-3p and miR-15b-5p. miR-221-3p and miR-15b-5p may be used as prognostic indicators for liver cancer. The miR-221-3p/miR-15b-5p-Axin2 axis may serve as a therapeutic target in patients with liver cancer.

SSTR5‑AS1 functions as a ceRNA to regulate CA2 by sponging miR‑15b‑5p for the development and prognosis of HBV‑related hepatocellular carcinoma

Long non-coding RNAs (lncRNAs) have been implicated in the development and progression of cancer. However, the mechanisms of lncRNAs in hepatitis B virus (HBV) infection-induced hepatocellular carcinoma (HCC) remain unclear. The study aimed to reveal the roles of lncRNAs for HBV-HCC based on the hypothesis of competing endogenous RNA (ceRNA). The lncRNA (GSE27462), miRNA (GSE76903) and mRNA (GSE121248) expression profiles were collected from the Gene Expression Omnibus database. Differentially expressed lncRNAs (DELs), genes (DEGs) and miRNAs (DEMs) were identified using the LIMMA or EdgeR package, respectively. The ceRNA network was constructed based on interaction pairs between miRNAs and mRNAs/lncRNAs. The functions of DEGs in the ceRNA network were predicted using the DAVID database, which was overlapped with the known HCC pathways of Comparative Toxicogenomics Database (CTD) to construct the HCC-related ceRNA network. The prognosis values [overall survival, (OS); recurrence-free survival (RFS)] of genes were validated using the Cancer Genome Atlas (TCGA) data with Cox regression analysis. The present study screened 38 DELs, 127 DEMs and 721 DEGs. A ceRNA network was constructed among 17 DELs, 12 DEMs and 173 DEGs, including the FAM138B-hsa-miR-30c-CCNE2/RRM2 and SSTR5-AS1-hsa-miR-15b-5p-CA2 ceRNA axes. Function enrichment analysis revealed the genes in the ceRNA network that participated in the p53 signaling pathway [cyclin E2 (CCNE2), ribonucleotide reductase M2 subunit (RRM2)] and nitrogen metabolism [carbonic anhydrase 2 (CA2)], which were also included in the pathways of the CTD. Univariate Cox regression analysis revealed that six RNAs (2 DELs: FAM138B, SSTR5-AS1; 2 DEMs: hsa-miR-149, hsa-miR-7; 2 DEGs: CCNE2, RRM2) were significantly associated with OS; while seven RNAs (1 DEL: LINC00284; 3 DEMs: hsa-miR-7, hsa-miR-15b, hsa-miR-30c-2; and 3 DEGs: RRM2, CCNE2, CA2) were significantly associated with RFS. In conclusion, FAM138B-hsa-miR-30c-CCNE2/RRM2 and the SSTR5-AS1-hsa-miR-15b-5p-CA2 ceRNA axes may be important mechanisms for HBV-related HCC.

MiR-146b inhibits autophagy in prostate cancer by targeting the PTEN/Akt/mTOR signaling pathway

Prostate cancer (PCa) is considered as a common visceral cancer in males and the sixth major cause of cancer-related deaths in males worldwide. Significant diagnostic and therapeutic advances have been made in the past decades. However, an improved understanding of their molecular mechanism is still needed. In the present research, we first detected the expression of miR-146b by quantitative real-time PCR (qRT-PCR) and found that miR-146b expression was increased in PCa. Subsequently, we found that miR-146b play an important role in the viability and proliferation capacity of PCa cells functionally. To explore the mechanism, we performed western blot to examine the autophagy-related markers, and found that miR‑146b may promote autophagy in PCa cells via activation of PTEN/AKT/mTOR signaling pathway. Furthermore, we performed the dual luciferase reporter assay to clarify the relationship between miR-146b and PTEN. In conclusion, this study demonstrated that miR-146b inhibited autophagy in PCa by targeting the PTEN/Akt/mTOR signaling pathway, and it could be a potential candidate for application in the treatment of PCa.

Overexpression of miR-15b Promotes Resistance to Sunitinib in Renal Cell Carcinoma

Aim: Sunitinib remains the frontline treatment for metastatic clear-cell renal cell carcinoma (ccRCC). Drug resistance is inevitable and related mechanism warrant insightful elaboration.

Methods: In silico data mining of GEO and TCGA datasets was performed to identify potential target micro-RNA. In vitro and in vivo studies were performed to validate findings.

Results: Reproduction of GEO datasets revealed miR-15b significantly upregulated in sunitinib- resistant ccRCC. Five out of seven ccRCC cell lines demonstrated significantly overexpressed miR-15b after sunitinib treatment. Vector-mediated overexpression of miR-15b significantly induced resistance to sunitinib in ccRCC cells. Overexpression of miR-15b significantly induced less population in G1 phase of cell cycle and less apoptosis in cells treated sunitinib. Expression of genes negatively correlated with miR-15b in TCGA ccRCC (KIRC) dataset were cross-referenced with predicted targets of miR-15b and CCNC was selected as potential target for resistance mediation. Overexpression of miR-15b suppressed CCNC expression and protein (Cyclin C) levels. Cyclin C-associated proteins CDK19 and CDK8 were also suppressed following miR-15b overexpression. Silencing of CCNC mimicked overexpression of miR-25 inducing cell cycle progression passing G1 phase and less apoptosis in ccRCC cells treated by sunitinib. Overexpression of miR-15b also counteracted suppression of migration and colony formation by sunitinib in ccRCC cell lines. In vivo mouse xenograft models showed recovered tumor growth with miR-15b expression in mice treated with sunitinib.

Conclusion: We here show miR-15b as a possible culprit for sunitinib resistance in ccRCC. Targeting miR-15b could potentially overcome drug resistance and related mechanism warrants further investigation.

MiR-15b regulates cell differentiation and survival by targeting CCNE1 in APL cell lines

MicroRNAs have been shown to be involved in various cell processes, including proliferation, apoptosis and differentiation. However, little is known about their function in granulopoiesis. In the present study, overexpression and knockdown experiments revealed that miR-15b was required to block the proliferation of NB4 and HL60 cells and induce them differentiated to granulocyte lineage. Moreover, we identified CCNE1 as a direct target of miR-15b, and demonstrated that CCNE1 was involved in cell differentiation and proliferation in acute promyelocytic leukemia cells. In addition, we demonstrated a novel pathway in which miR-15b regulated cells arrested in the G0/G1 phase and promoted terminal differentiation of cells by targeting CCNE1, which could modulate the cell cycle effort pRb in APL cells. These events blocked cell proliferation and promoted granulocyte differentiation. In conclusion, our data highlighted, for the first time, the important role of miR-15b in myeloid differentiation and suggested the potential role of miR-15b in cancer therapy.

Silver, Gold, and Iron Oxide Nanoparticles Alter miRNA Expression but Do Not Affect DNA Methylation in HepG2 Cells

The increasing use of nanoparticles (NPs) in various applications entails the need for reliable assessment of their potential toxicity for humans. Originally, studies concerning the toxicity of NPs focused on cytotoxic and genotoxic effects, but more recently, attention has been paid to epigenetic changes induced by nanoparticles. In the present research, we analysed the DNA methylation status of genes related to inflammation and apoptosis as well as the expression of miRNAs related to these processes in response to silver (AgNPs), gold (AuNPs), and superparamagnetic iron oxide nanoparticles (SPIONs) at low cytotoxic doses in HepG2 cells. There were no significant differences between treated and control cells in the DNA methylation status. We identified nine miRNAs, the expression of which was significantly altered by treatment with nanoparticles. The highest number of changes was induced by AgNPs (six miRNAs), followed by AuNPs (four miRNAs) and SPIONs (two miRNAs). Among others, AgNPs suppressed miR-34a expression, which is of particular interest since it may be responsible for the previously observed AgNPs-mediated HepG2 cells sensitisation to tumour necrosis factor (TNF). Most of the miRNAs affected by NP treatment in the present study have been previously shown to inhibit cell proliferation and tumourigenesis. However, based on the observed changes in miRNA expression we cannot draw definite conclusions regarding the pro- or anti-tumour nature of the NPs under study. Further research is needed to fully elucidate the relation between observed changes in miRNA expression and the effect of NPs observed at the cellular level. The results of the present study support the idea of including epigenetic testing during the toxicological assessment of the biological interaction of nanomaterials.

MiR-15b is a key regulator of proliferation and apoptosis of chondrocytes from patients with condylar hyperplasia by targeting IGF1, IGF1R and BCL2

OBJECTIVE

This study aimed to explore potential microRNAs (miRNAs), which participate in the pathological process of condylar hyperplasia (CH) through targeting specific proliferation- and apoptosis- related genes of chondrocytes.

METHODS

Insulin-like growth factor 1 (IGF1), IGF1 receptor (IGF1R) and B-cell CLL/lymphoma 2 (BCL2) in CH cartilage were detected by real-time polymerase chain reaction (PCR), Western blot, immunohistochemistry and immunofluorescence. MiRanda and TargetScanS algorithms were used to predict certain miRNAs in CH chondrocytes concurrently modulating the above three genes. MiR-15b was screened and identified using real-time PCR. After transfection of miR-15b mimics or inhibitor into CH chondrocytes, expression of the above three genes was detected by real-time PCR and western blot, meanwhile, cell proliferation and apoptosis was examined by CCK8, cell cycle assays, flow cytometry and Hoechst staining. Dual luciferase activity was performed to identify the direct regulation of miR-15b on IGF1, IGF1R and BCL2.

RESULTS

Expression of IGF1, IGF1R and BCL2 increased in CH cartilage. Seven microRNAs concurrently correlated with IGF1, IGF1R and BCL2. Among them, only miR-15b significantly changed in CH chondrocytes. Overexpression of miR-15b in CH chondrocytes suppressed the expression of IGF1, IGF1R and BCL2, while it increased when miR-15b was knockdown. Furthermore, miR-15b suppressed their expression by directly binding to its 3'-UTR in these cells. Besides, miR-15b hampered chondrocytes proliferation through targeting IGF1 and IGF1R and accelerated chondrocytes apoptosis through targeting BCL2.

CONCLUSION

Suppressed miR-15b contributed to enhanced proliferation capacity and weakened apoptosis of chondrocytes through augmentation of IGF1, IGF1R and BCL2, thereby resulting in development of CH.

Long noncoding RNA MAGI2-AS3 regulates CCDC19 expression by sponging miR-15b-5p and suppresses bladder cancer progression

Bladder cancer (BCa) belongs to a popular urological malignancy and leads to large numbers of deaths worldwide. Recently, emerging evidences indicate that long noncoding RNAs (lncRNAs) are closely related with BC occurrence and progression. However, the function of lncRNA MAGI2-AS3 remains poorly understood in BC. In this present study, we screened out a novel lncRNA MAGI2-AS3 whose expression was downregulated in BCa tissues. We showed that MAGI2-AS3 downregulation in BCa patients indicated a poor prognosis. Functionally, we showed that MAGI2-AS3 overexpression inhibits proliferation, migration and invasion of BCa cells. Moreover, ectopic expression of MAGI2-AS3 suppresses BCa growth in vivo. Bioinformatics analysis revealed that MAGI2-AS3 could serve as a competing endogenous RNA (ceRNA) for miR-15b-5p. In the meantime, miR-15b-5p directly targeted CCDC19, a tumor suppressor in BCa. Rescue assays demonstrated that knockdown of CCDC19 restored the proliferation, migration and invasion of BCa cells suppressed by MAGI2-AS3 overexpression. In conclusion, this study identified a novel mechanism that MAGI2-AS3/miR-15b-5p/CCDC19 signaling pathway regulates BCa progression.

miR-103/miR-195/miR-15b Regulate SALL4 and Inhibit Proliferation and Migration in Glioma

Glioma is the common highly malignant primary brain tumor. However, the molecular pathways that result in the pathogenesis of glioma remain elusive. In this study, we found that microRNA-103 (miR-103), microRNA-195 (miR-195), or microRNA-15b (miR-15b), which all have the same 5' "seed" miRNA portion and share common binding sites in the SALL4 3'-untranslated region (UTR), were downregulated in glioma tissues and cell lines. These miRNAs suppressed glioma cell proliferation, migration, and invasion, induced cell apoptosis, and decreased the level of the SALL4 protein, but not that of SALL4 mRNA, which was identified as a direct target of all three miRNAs. The caspase-3/7 activity expression in U251 cells overexpressing these miRNAs was rescued during SALL4 upregulation. An obvious inverse correlation was observed between SALL4 and miR-103 or miR-195 expression levels in clinical glioma samples. Moreover, enforced expression of SALL4 stimulated cell proliferation, migration, and invasion. In conclusion, these data suggest that miR-103, miR-195, and miR-15b post-transcriptionally downregulated the expression of SALL4 and suppressed glioma cell growth, migration, and invasion, and increased cell apoptosis. These results provide a potential therapeutic target that may downregulate SALL4 in glioma.