miR-93 promotes cell proliferation in gliomas through activation of PI3K/Akt signaling pathway

The possible correlation between miR-762, Hippo signaling pathway, TWIST1, and SMAD3 in lung cancer and chronic inflammatory diseases

MicroRNAs are small RNA molecules that have a significant role in translational repression and gene silencing through binding to downstream target mRNAs. MiR-762 can stimulate the proliferation and metastasis of various types of cancer. Hippo pathway is one of the pathways that regulate tissue development and carcinogenesis. Dysregulation of this pathway plays a vital role in the progression of cancer. This study aimed to evaluate the possible correlation between miR-762, the Hippo signaling pathway, TWIST1, and SMAD3 in patients with lung cancer, as well as patients with chronic inflammatory diseases. The relative expression of miR-762, MST1, LATS2, YAP, TWIST1, and SMAD3 was determined in 50 lung cancer patients, 30 patients with chronic inflammatory diseases, and 20 healthy volunteers by real-time PCR. The levels of YAP protein and neuron-specific enolase were estimated by ELISA and electrochemiluminescence immunoassay, respectively. Compared to the control group, miR-762, YAP, TWIST1, and SMAD3 expression were significantly upregulated in lung cancer patients and chronic inflammatory patients, except SMAD3 was significantly downregulated in chronic inflammatory patients. MST1, LATS2, and YAP protein were significantly downregulated in all patients. MiR-762 has a significant negative correlation with MST1, LATS2, and YAP protein in lung cancer patients and with MST1 and LATS2 in chronic inflammatory patients. MiR-762 may be involved in the induction of malignant behaviors in lung cancer through suppression of the Hippo pathway. MiR-762, MST1, LATS2, YAP mRNA and protein, TWIST1, and SMAD3 may be effective diagnostic biomarkers in both lung cancer patients and chronic inflammatory patients. High YAP, TWIST1, SMA3 expression, and NSE level are associated with a favorable prognosis for lung cancer.

Diagnostic and Prognostic Value of miR-93 in Prostate Cancer: A Meta-Analysis and Bioinformatics Analysis

Background

Accurate and non-invasive diagnostic and prognostic markers are necessary to improve patient outcomes. MicroRNAs have been proposed as relatively non-invasive and pertinent biomarkers. miR-93 has been studied for its potential as a diagnostic and prognostic marker in prostate cancer (PCa), but findings from individual studies are inconsistent. We conducted a meta-analysis of its overall differential expression in 13 PCa studies and a bioinformatics analysis to provide a comprehensive appraisal of its diagnostic and prognostic role.

Methods

We searched all published papers on miR-93 expression in PCa up to Nov 30, 2022 using PubMed, Science Direct, Web of Science, Cochrane Central Register of Controlled Trials databases. We used RevMan software to Meta-analyze the included literature. A bioinformatics analysis of genes and pathways that might be target to the effect of the mature miR-93-5p was carried out.

Results

The pooled standardized mean difference (SMD) of miR-93 expression in PCa, its area under the curve (AUC) and hazard ratio (HR) were 1.26, 95% CI [-0.34-2.86], 0.84, 95% CI [0.76 -0.93] and 1.67, 95% CI [0.98, 2.84] respectively. Bioinformatics analysis revealed that mature miR-93-5p may regulate genes such as SMAD1, SMAD7 and MAPK and the PI3K-Akt signaling pathways.

Conclusion

miR-93 has significant diagnostic and prognostic value in PCa. These findings highlight the potential of miR-93 as a non-invasive biomarker for PCa and may contribute to earlier detection and prognostic assessment. The target genes and signaling pathways regulated by miR-93 may provide insights into the underlying molecular mechanisms of PCa.

Forkhead box transcription factors (FOXOs and FOXM1) in glioma: from molecular mechanisms to therapeutics

Glioma is the most aggressive and malignant type of primary brain tumor, comprises the majority of central nervous system deaths, and is categorized into different subgroups according to its histological characteristics, including astrocytomas, oligodendrogliomas, glioblastoma multiforme (GBM), and mixed tumors. The forkhead box (FOX) transcription factors comprise a collection of proteins that play various roles in numerous complex molecular cascades and have been discovered to be differentially expressed in distinct glioma subtypes. FOXM1 and FOXOs have been recognized as crucial transcription factors in tumor cells, including glioma cells. Accumulating data indicates that FOXM1 acts as an oncogene in various types of cancers, and a significant part of studies has investigated its function in glioma. Although recent studies considered FOXO subgroups as tumor suppressors, there are pieces of evidence that they may have an oncogenic role. This review will discuss the subtle functions of FOXOs and FOXM1 in gliomas, dissecting their regulatory network with other proteins, microRNAs and their role in glioma progression, including stem cell differentiation and therapy resistance/sensitivity, alongside highlighting recent pharmacological progress for modulating their expression.

The role of ncRNA in the co-regulation of autophagy and exosome pathways during cancer progression

Since its discovery a few decades ago, autophagy has been recognized as a crucial signaling pathway, linked to the recycling of cellular components in nutrient stress. Autophagy is a two-way sword, playing a dual role in tumorigenesis. In this catabolic process, dysfunctional organelles, biomolecules, and misfolded proteins are sequestered in the autophagosome and sent to the lysosome for degradation. Alongside, there are cellular messengers called exosomes, which are released from cells and are known to communicate and regulate metabolism in recipient cells. Multivesicular bodies (MVB) act as the intricate link between autophagy and exosome pathways. The continuous crosstalk between the two pathways is coordinated and regulated by multiple players among which ncRNA is the emerging candidates. The exosomes carry varied cargo of which non-coding RNA exerts an immediate regulatory effect on recipient cells. ncRNA is known to exhibit dual behavior in both promoting and inhibiting tumor growth. There is increasing evidence for the involvement of ncRNAs' in the regulation of different hallmarks of cancer. Different ncRNAs are involved in the co-regulation of autophagy and exosome pathways and therefore represent a superior therapeutic approach to target cancer chemoresistance. Here, we will discuss the ncRNA involved in regulating autophagy, and exosomes pathways and its relevance in cancer therapeutics.

MiR-93-5p inhibits retinal neurons apoptosis by regulating PDCD4 in acute ocular hypertension model

The present study focused on the effect of miR-93-5p on apoptosis of retinal neurons in acute ocular hypertension (AOH) model by regulating PDCD4 and explored its related mechanism. We detected that miR-93-5p expression was decreased and PDCD4 expression was increased in the AOH retina by qRT-PCR. Therefore, we explored the role of miR-93-5p and PDCD4. MiR-93-5p overexpression inhibited the apoptosis of retinal neurons and the expression of PDCD4 in vivo and in vitro. Inhibiting the expression of PDCD4 via transfected interfering RNA decreased the apoptosis of retinal cells and increased the expression of PI3K/Akt pathway-related proteins in vitro. However, the addition of PI3K protein inhibitor LY294002 reversed this effect, leading to a decrease of PI3K/Akt pathway protein expression and an increase of apoptosis-related protein Bax/Bcl-2 expression ratio. Finally, up-regulating miR-93-5p or down-regulating PDCD4 increased the expression of PI3K/Akt pathway protein in vivo. In conclusion, under the condition of AOH injury, miR-93-5p-inhibiting PDCD4 expression reduced the apoptosis of retinal neurons by activating PI3K/Akt pathway.

MiRNA-93: a novel signature in human disorders and drug resistance

miRNA-93 is a member of the miR-106b-25 family and is encoded by a gene on chromosome 7q22.1. They play a role in the etiology of various diseases, including cancer, Parkinson's disease, hepatic injury, osteoarthritis, acute myocardial infarction, atherosclerosis, rheumatoid arthritis, and chronic kidney disease. Different studies have found that this miRNA has opposing roles in the context of cancer. Recently, miRNA-93 has been downregulated in breast cancer, gastric cancer, colorectal cancer, pancreatic cancer, bladder cancer, cervical cancer, and renal cancer. However, miRNA-93 is up-regulated in a wide variety of malignancies, such as lung, colorectal, glioma, prostate, osteosarcoma, and hepatocellular carcinoma. The aim of the current review is to provide an overview of miRNA-93's function in cancer disorder progression and non-cancer disorders, with a focus on dysregulated signaling pathways. We also give an overview of this miRNA's function as a biomarker of prognosis in cancer and emphasize how it contributes to drug resistance based on in vivo, in vitro, and human studies. Video Abstract.

Interactive role of miR-29, miR-93, miR-205, and VEGF in salivary adenoid cystic carcinoma

OBJECTIVES

Salivary adenoid cystic carcinoma (SACC) is one of the most common salivary gland tumors in which patients encounter local recurrence and lung metastases. Understanding prognostic biomarkers in SACC is essential for future development in prognosis and treatment. This study aimed to assess the expression level of vascular endothelial growth factor (VEGF) and its potential regulatory microRNAs in SACC for prognostic determination. MATERIAL AND METHODS: The expression of VEGF in SACC samples was assessed using immunohistochemistry. Potential regulatory microRNAs were evaluated using quantitative reverse transcription-polymerase chain reaction. Associations between VEGF and microRNAs expression and clinicopathological parameters were investigated.

RESULTS

VEGF expression levels positively correlated with histologic grade (p = .004) and treatment modality (p = .04). Decreased expression of miR-29a (p = .01) and increased expression of miR-93-5p and miR-205 (both p < .0001) were observed in SACC compared to normal salivary gland tissue. MiR-93-5p showed a positive association (p = .02) with VEGF overexpression.

CONCLUSIONS

Our results showed the downregulation of miR-29 and overexpression of miR-93 and miR-205 in the SACC group, and the correlation between miR-93 and VEGF suggests these biomarkers as potential prognostic markers in the future.

Emerging roles of PHLPP phosphatases in the nervous system

It has been more than a decade since the discovery of a novel class of phosphatase, the Pleckstrin Homology (PH) domain Leucine-rich repeat Protein Phosphatases (PHLPP). Over time, they have been recognized as crucial regulators of various cellular processes, such as memory formation, cellular survival and proliferation, maintenance of circadian rhythm, and others, with any deregulation in their expression or cellular localization causing havoc in any cellular system. With the ever-growing number of downstream substrates across multiple tissue systems, a web is emerging wherein the central point is PHLPP. A slight nick in the normal signaling cascade of the two isoforms of PHLPP, namely PHLPP1 and PHLPP2, has been recently found to invoke a variety of neurological disorders including Alzheimer's disease, epileptic seizures, Parkinson's disease, and others, in the neuronal system. Improper regulation of the two isoforms has also been associated with various disease pathologies such as diabetes, cardiovascular disorders, cancer, musculoskeletal disorders, etc. In this review, we have summarized all the current knowledge about PHLPP1 (PHLPP1α and PHLPP1β) and PHLPP2 and their emerging roles in regulating various neuronal signaling pathways to pave the way for a better understanding of the complexities. This would in turn aid in providing context for the development of possible future therapeutic strategies.

PHLPPs: Emerging players in metabolic disorders

That reversible protein phosphorylation by kinases and phosphatases occurs in metabolic disorders is well known. Various studies have revealed that a multi-faceted and tightly regulated phosphatase, pleckstrin homology domain leucine-rich repeat protein phosphatase (PHLPP)-1/2 displays robust effects in cardioprotection, ischaemia/reperfusion (I/R), and vascular remodelling. PHLPP1 promotes foamy macrophage development through ChREBP/AMPK-dependent pathways. Adipocyte-specific loss of PHLPP2 reduces adiposity, improves glucose tolerance,and attenuates fatty liver via the PHLPP2-HSL-PPARα axis. Discoveries of PHLPP1-mediated insulin resistance and pancreatic β cell death via the PHLPP1/2-Mst1-mTORC1 triangular loop have shed light on its significance in diabetology. PHLPP1 downregulation attenuates diabetic cardiomyopathy (DCM) by restoring PI3K-Akt-mTOR signalling. In this review, we summarise the functional role of, and cellular signalling mediated by, PHLPPs in metabolic tissues and discuss their potential as therapeutic targets.

Transcription factor SNAI2 exerts pro-tumorigenic effects on glioma stem cells via PHLPP2-mediated Akt pathway

The current study aimed to investigate the effects associated with SNAI2 on the proliferation of glioma stem cells (GSCs) to elucidate its underlying molecular mechanism in the development of glioma. The expression of Snail family transcriptional repressor 2 (SNAI2) in glioma tissues was initially predicted via bioinformatics analysis and subsequently confirmed by reverse transcription quantitative polymerase chain reaction (RT-qPCR), which revealed that SNAI2 was highly expressed in glioma tissues as well as GSCs, with an inverse correlation with overall glioma patient survival detected. Loss- and gain- of-function assays were performed to determine the roles of SNAI2 and pleckstrin homology domain and leucine rich repeat protein phosphatase 2 (PHLPP2) on GSC viability, proliferation and apoptosis. Data were obtained indicating that SNAI2 promoted the proliferation of GSCs, while overexpressed PHLPP2 brought about a contrasting trend. As detected by chromatin immunoprecipitation, RT-qPCR and agarose gel electrophoresis, SNAI2 bound to the promoter region of PHLPP2 and repressed the transcription of PHLPP2 while SNAI2 was found to inhibit PHLPP2 resulting in activation of the Akt pathway. Finally, the roles of SNAI2 and PHLPP2 were verified in glioma growth in nude mice xenografted with tumor. Taken together, the key findings of the present study suggest that SNAI2 may promote the proliferation of GSCs through activation of the Akt pathway by downregulating PHLPP2.

Discovery of novel targets and mechanisms of MEK inhibitor Selumetinib for LGG treatment based on molecular docking and molecular dynamics simulation

Based on molecular docking and molecular dynamics simulation, to find a new target and mechanism of MEK inhibitor Selumetinib in the treatment of low-grade glioma (LGG), and to provide theoretical guidance for its clinical medication. All possible targets of Selumetinib were fished through the compound target prediction database. New targets of Selumetinib in the treatment of LGG were found and its mechanism was evaluated employing molecular docking, gene difference analysis, molecular dynamics simulation, and protein subcellular localization prediction. A total of 100 Selumetinib targets and 85 LGG-related targets were screened in this study. There were 7 active targets at the intersection of the two. Through protein interaction (PPI), gene enrichment analysis, and gene difference analysis, one effective target of Selumetinib was finally screened, CDK2 mainly existing in the cytoplasm, endoplasmic reticulum, and plasma membrane; the target plays a role in the treatment of LGG by inhibiting the signal pathways of PI3K Akt and participating in biological processes such as peptide amino acid modification, regulation of intracellular signal transduction, and positive regulation of cell metabolism. CDK2 may be a new direction of Selumetinib in the clinical treatment of LGG.

MicroRNAs and drug resistance in colorectal cancer with special focus on 5-fluorouracil

Colorectal cancer is globally one of the most common cancers in all age groups. The current chemotherapy combinations for colorectal cancer treatment include 5-fluorouracil-based regimens; however, drug resistance remains one of the main reasons for chemotherapy failure and disease recurrence. Many studies have determined colorectal cancer chemoresistance mechanisms such as drug efflux, cell cycle arrest, DNA damage repair, apoptosis, autophagy, vital enzymes, epigenetic, epithelial-mesenchymal transition, stem cells, and immune system suppression. Several microRNAs affect drug resistance by regulating the drug resistance-related target genes in colorectal cancer. These drug resistance-related miRNAs may be used as promising biomarkers for predicting drug response or as potential therapeutic targets for treating patients with colorectal cancer. This work reviews and discuss the role of selected microRNAs in 5-fluorouracil resistance and their molecular mechanisms in colorectal cancer.

Sporadic Alzheimer's Disease- and Neurotoxicity-Related microRNAs Affecting Key Events of Tau-Driven Adverse Outcome Pathway Toward Memory Loss

BACKGROUND

A complex network of aging-related homeostatic pathways that are sensitive to further deterioration in the presence of genetic, systemic, and environmental risk factors, and lifestyle, is implicated in the pathogenesis of progressive neurodegenerative diseases, such as sporadic (late-onset) Alzheimer's disease (sAD).

OBJECTIVE

Since sAD pathology and neurotoxicity share microRNAs (miRs) regulating common as well as overlapping pathological processes, environmental neurotoxic compounds are hypothesized to exert a risk for sAD initiation and progression.

METHODS

Literature search for miRs associated with human sAD and environmental neurotoxic compounds was conducted. Functional miR analysis using PathDip was performed to create miR-target interaction networks.

RESULTS

The identified miRs were successfully linked to the hypothetical starting point and key events of the earlier proposed tau-driven adverse outcome pathway toward memory loss. Functional miR analysis confirmed most of the findings retrieved from literature and revealed some interesting findings. The analysis identified 40 miRs involved in both sAD and neurotoxicity that dysregulated processes governing the plausible adverse outcome pathway for memory loss.

CONCLUSION

Creating miR-target interaction networks related to pathological processes involved in sAD initiation and progression, and environmental chemical-induced neurotoxicity, respectively, provided overlapping miR-target interaction networks. This overlap offered an opportunity to create an alternative picture of the mechanisms underlying sAD initiation and early progression. Looking at initiation and progression of sAD from this new angle may open for new biomarkers and novel drug targets for sAD before the appearance of the first clinical symptoms.

Crosstalk between miRNA and PI3K/AKT/mTOR signaling pathway in cancer

Phosphoinositide-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most important proliferative signaling pathways with critical undeniable function in various aspects of cancer initiation/progression, including proliferation, apoptosis, metastasis, angiogenesis, and drug resistance. On the other hand, numerous genetic alterations in the key genes involved in the PI3K/AKT/mTOR signaling pathway have been identified in multiple solid and hematological tumors. In addition, accumulating recent evidences have demonstrated a reciprocal interaction between this signaling pathway and microRNAs, a large group of small non-coding RNAs. Therefore, in this review, it was attempted to discuss about the interaction between key components of PI3K/AKT/mTOR signaling pathway with various miRNAs and their importance in cancer biology.

MicroRNA‑93 knockdown inhibits acute myeloid leukemia cell growth via inactivating the PI3K/AKT pathway by upregulating DAB2

Acute myeloid leukemia (AML) is associated with a poor prognosis in elderly adults and currently lacks optimal treatment strategies. MicroRNAs (miRNAs or miRs) have increasingly been reported to be associated with AML progression; however, the mechanisms of action of miR-93 in AML with the involvement of disabled 2 (DAB2) are currently unknown. In the present study, miR-93 expression was assessed in patients with AML and in AML cell lines. The association between miR-93 expression and the pathological characteristics of patients with AML was analyzed. AML cells were then transfected to knockdown or overexpress miR-93 in order to elucidate its function in AML progression. The target gene of miR-93 was assessed using a dual-luciferase reporter gene assay. The expression levels of miR-93, DAB2 and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway-related proteins were measured and in vivo experiments were conducted to confirm the results. It was observed that miR-93 was highly expressed in patients with AML and in AML cells. The knockdown of miR-93 in HL-60 cells inhibited AML cell proliferation and resistance to apoptosis, while the overexpression of miR-93 in THP-1 cells led to contrasting results. Moreover, miR-93 targeted DAB2 to inactivate the PI3K/AKT pathway, and the overexpression of DAB2 reversed the effects of miR-93 on THP-1 cell growth. Tumor volume, tumor weight, and the positive expression of Ki67, survivin and p53 were increased in THP-1 cells overexpressing miR-93. On the whole, the present study demonstrates that miR-93 is highly expressed in AML cells, and that the suppression of miR-93 inhibits AML cell growth by targeting DAB2 and inhibiting the PI3K/AKT pathway.

miR-451 suppresses EMT and metastasis in glioma cells

The metastasis of tumor cells is a challenge for the clinical treatment of glioma. Epithelial-mesenchymal transition (EMT) contributes to glioma cell invasiveness. Our previous study confirmed that the expression of miRNA-451, which inhibits the PI3K/Akt signaling pathway by directly targeting CAB39 and plays a repressive role in glioma, is downregulated in glioma. However, the specific mechanism of miRNA-451 regulation in glioma is unclear. In this study, we investigated whether miRNA-451 blocks the processes of EMT and metastasis in glioma cells in vivo and in vitro. By targeting CAB39, miRNA-451 likely triggers the PI3K/Akt/Snail signaling pathway to reduce glioma proliferation, invasion, migration and EMT. We used Western blotting experiments to demonstrate that overexpression of miRNA-451 significantly reduced p-AKT(Ser473), N-cadherin, Vimentin, Twist, Snail and Cyclin D1 expression and increased E-cadherin expression. We demonstrated that overexpression of miR-451 suppressed glioma cell proliferation, invasion, migration and EMT by MTT and colony formation assays, Transwell assays, wound healing assays and animal experiments. Taken together, these results suggest that miRNA-451 can reduce EMT and metastasis in glioma cells through the suppression of the PI3K/Akt/Snail signaling pathway by targeting CAB39 in vitro and in vivo. miR-451 may be a new target for glioma treatment.

MicroRNAs' role in the environment-related non-communicable diseases and link to multidrug resistance, regulation, or alteration

The discovery of microRNAs (miRNAs) 20 years ago has advocated a new era of "small molecular genetics." About 2000 miRNAs are present that regulate one third of the genome. MiRNA dysregulated expression arising as a response to our environment insult or stress or changes may contribute to several diseases, namely non-communicable diseases, including tumor growth. Their presence in body fluids, reflecting level alteration in various cancers, merit circulating miRNAs as the "next-generation biomarkers" for early-stage tumor diagnosis and/or prognosis. Herein, we performed a comprehensive literature search focusing on the origin, biosynthesis, and role of miRNAs and summarized the foremost studies centering on miR value as non-invasive biomarkers in different environment-related non-communicable diseases, including various cancer types. Moreover, during chemotherapy, many miRNAs were linked to multidrug resistance, via modulating numerous, environment triggered or not, biological processes and/or pathways that will be highlighted as well.

A molecular signature associated with prolonged survival in glioblastoma patients treated with regorafenib

BACKGROUND

Patients with glioblastoma (GBM) have a dramatically poor prognosis. The recent REGOMA trial suggested an overall survival (OS) benefit of regorafenib in recurrent GBM patients. Considering the extreme genetic heterogeneity of GBMs, we aimed to identify molecular biomarkers predictive of differential response to the drug.

METHODS

Total RNA was extracted from tumor samples of patients enrolled in the REGOMA trial. Genome-wide transcriptome and micro (mi)RNA profiles were associated with patients' OS and progression-free survival.

RESULTS

In the first step, a set of 11 gene transcripts (HIF1A, CTSK, SLC2A1, KLHL12, CDKN1A, CA12, WDR1, CD53, CBR4, NIFK-AS1, RAB30-DT) and 10 miRNAs (miR-93-5p, miR-203a-3p, miR-17-5p, let-7c-3p, miR-101-3p, miR-3607-3p, miR-6516-3p, miR-301a-3p, miR-23b-3p, miR-222-3p) was filtered by comparing survival between regorafenib and lomustine arms. In the second step, a mini-signature of 2 gene transcripts (HIF1A, CDKN1A) and 3 miRNAs (miR-3607-3p, miR-301a-3p, miR-93-5p) identified a subgroup of patients showing prolonged survival after regorafenib administration (median OS range, 10.6-20.8 mo).

CONCLUSIONS

The study provides evidence that a signature based on the expression of 5 biomarkers could help identify a subgroup of GBM patients exhibiting a striking survival advantage when treated with regorafenib. Although the presented results must be confirmed in larger replication cohorts, the study highlights potential biomarker options to help guide the clinical decision among regorafenib and other treatments in patients with relapsing GBM.

Identification of MiR-93-5p Targeted Pathogenic Markers in Acute Myeloid Leukemia through Integrative Bioinformatics Analysis and Clinical Validation

Acute myeloid leukemia (AML) is a type of hematological malignancy with diverse genetic pathogenesis. Identification of the miR-93-5p targeted pathogenic markers could be useful for AML diagnosis and potential therapy. We collected 751 miR-93-5p targeted and AML-related genes by integrating the results of multiple databases and then used the expression profile of TCGA-LAML to construct a coexpression function network of AML WGCNA. Based on the clinical phenotype and module trait relationship, we identified two modules (brown and yellow) as interesting dysfunction modules, which have a significant association with cytogenetics risk and FAB classification systems. GO enrichment and KEGG analysis showed that these modules are mainly involved with cancer-associated pathways, including MAPK signal pathway, p53 signal pathway, JAK-STAT signal pathway, TGF-beta signaling pathway, mTOR signaling pathway, VEGF signaling pathway, both associated with the occurrence of AML. Besides, using the STRING database, we discovered the top 10 hub genes in each module, including MAPK1, ACTB, RAC1, GRB2, MDM2, ACTR2, IGF1R, CDKN1A, YWHAZ, and YWHAB in the brown module and VEGFA, FGF2, CCND1, FOXO3, IGFBP3, GSF1, IGF2, SLC2A4, PDGFBM, and PIK3R2 in the yellow module. The prognosis analysis result showed that six key pathogens have significantly affected the overall survival and prognosis in AML. Interestingly, VEGF with the most significant regulatory relationship in the yellow modules significantly positively correlated with the clinical phenotype of AML. We used qPCR and ELISA to verify miR-93-5p and VEGF expression in our clinical samples. The results exhibited that miR-93-5p and VEGF were both highly expressed in AML.

Transcription elongation factor A-like 7, regulated by miR-758-3p inhibits the progression of melanoma through decreasing the expression levels of c-Myc and AKT1

BACKGROUND

Ectopic expression of transcription elongation factor A (SII)-like 7 (TCEAL7) has been observed in several kinds of cancers, but its role in melanoma is still unclear. This study was carried out to investigate TCEAL7 role in melanoma progression, and uncover the underlying mechanisms.

METHODS

TCEAL7 expression levels in melanoma tissues and cells were determined by using real-time quantitative PCR (RT-PCR) and western blotting. CCK-8, transwell chambers, flow cytometry, starch assay and tumorigenesis assay were applied to detect cell growth, invasion, apoptosis, migration and tumorigenesis, respectively.

RESULTS

A low expression level of TCEAL7 was observed in melanoma tissues and cells, which was associated with malignant clinical process and poor prognosis. TCEAL7 negatively modulated AKT1, AKT2, c-Myc, N-cadherin and PCNA expression and inhibited cancer progression via decreasing AKT1 and c-Myc levels. In addition, TCEAL7 was negatively modulated by miR-758-3p which promoted melanoma progression. Moreover, overexpression of TCEAL7 abolished miR-758-3p role in promoting melanoma progression.

CONCLUSION

This study demonstrated that TCEAL7, regulated by miR-758-3p inhibited melanoma progression through decreasing the expression levels of c-Myc and AKT1.

The microRNAs miR-302d and miR-93 inhibit TGFB-mediated EMT and VEGFA secretion from ARPE-19 cells

The transforming growth factor-beta (TGFB) plays an essential role in the pathogenesis of some ophthalmologic diseases, including neovascular age-related macular degeneration (nAMD) and proliferative vitreoretinopathy (PVR). TGFB activates the transcription factors SMAD2 and SMAD3 via the TGFB receptor, which together activate several genes, including VEGFA. TGFB treated ARPE-19 cells show an increased proliferation rate and undergo epithelial to mesenchymal transition (EMT). Since microRNAs (miRNAs) are capable of inhibiting the translation of multiple genes, we screened for miRNAs that regulate the TGFB signalling pathways at multiple levels. In this study, we focused on two miRNAs, miR-302d and miR-93, which inhibit TGFB signalling pathway and therefore TGFB-induced EMT transition as well as VEGFA secretion from ARPE-19 cells. Furthermore, we could show that both miRNAs can retransform TGFB-stimulated mesenchymal ARPE-19 cells towards the morphological epithelial-like state. Taken together, transient overexpression of these miRNAs in RPE cells might be a promising approach for further translational strategies.

Autophagy-Associated lncRNAs: Promising Targets for Neurological Disease Diagnosis and Therapy

Neurological diseases are a major threat to global public health and prosperity. The number of patients with neurological diseases is increasing due to the population aging and increasing life expectancy. Autophagy is one of the crucial mechanisms to maintain nerve cellular homeostasis. Numerous studies have demonstrated that autophagy plays a dual role in neurological diseases. Long noncoding RNAs (lncRNAs) are a vital class of noncoding RNAs with a length of more than 200 nucleotides and cannot encode proteins themselves but are expressed in most neurological diseases. An early phase, emerging knowledge has revealed that long noncoding RNAs (lncRNAs) are crucial in autophagy regulation. Furthermore, autophagy-associated lncRNAs can promote the development of neurological diseases or slow their progression. In this review, we introduce a general overview of lncRNA functional mechanisms and summarizes the recent progress of lncRNAs on autophagy regulation in neurological diseases to reveal possible novel therapeutic targets or useful biomarkers.

Flaming the fight against cancer cells: the role of microRNA-93

There have been attempts to develop novel anti-tumor drugs in cancer therapy. Although satisfying results have been observed at a consequence of application of chemotherapeutic agents, the cancer cells are capable of making resistance into these agents. This has forced scientists into genetic manipulation as genetic alterations are responsible for generation of a high number of cancer cells. MicroRNAs (miRs) are endogenous, short non-coding RNAs that affect target genes at the post-transcriptional level. Increasing evidence reveals the potential role of miRs in regulation of biological processes including angiogenesis, metabolism, cell proliferation, cell division, and cell differentiation. Abnormal expression of miRs is associated with development of a number of pathologic events, particularly cancer. MiR-93 plays a significant role in both physiological and pathological mechanisms. At the present review, we show how this miR dually affects the proliferation and invasion of cancer cells. Besides, we elucidate the oncogenesis or oncosuppressor function of miR-93.

Autophagy in cancers including brain tumors: role of MicroRNAs

Autophagy has a crucial role in many cancers, including brain tumors. Several types of endogenous molecules (e.g. microRNAs, AKT, PTEN, p53, EGFR, and NF1) can modulate the process of autophagy. Recently miRNAs (small non-coding RNAs) have been found to play a vital role in the regulation of different cellular and molecular processes, such as autophagy. Deregulation of these molecules is associated with the development and progression of different pathological conditions, including brain tumors. It was found that miRNAs are epigenetic regulators, which influence the level of proteins coded by the targeted mRNAs with any modification of the genetic sequences. It has been revealed that various miRNAs (e.g., miR-7-1-3p, miR-340, miR-17, miR-30a, miR-224-3p, and miR-93), as epigenetic regulators, can modulate autophagy pathways within brain tumors. A deeper understanding of the underlying molecular targets of miRNAs, and their function in autophagy pathways could contribute to the development of new treatment methods for patients with brain tumors. In this review, we summarize the various miRNAs, which are involved in regulating autophagy in brain tumors. Moreover, we highlight the role of miRNAs in autophagy-related pathways in different cancers.

MicroRNA-527 Induces Proliferation and Cell Cycle in Esophageal Squamous Cell Carcinoma Cells by Repressing PH Domain Leucine-Rich-Repeats Protein Phosphatase 2

Increasing evidence indicated that microRNAs served dominant roles in carcinogenesis and cancer progression by targeting potential downstream genes. In our study, we found that miR-527 was an upregulated expression in human esophageal squamous cell carcinoma (ESCC) cells and tissues. Furthermore, overexpression of miR-527 promoted cell proliferation and colony formation, enhanced anchorage-independent growth ability, and contributed to cell cycle. In addition, protein phosphatase 2 (PHLPP2) was identified as the direct downstream target gene of miR-527 and was confirmed by luciferase gene reporter assay. In summary, we concluded that miR-527 acted as an oncogenic microRNA in ESCC development by directly targeting PHLPP2 might be a novel therapeutic target for the treatment of ESCC.

miR-106B-25 Cluster expression: a comparative human and canine osteosarcoma study

Background

Osteosarcoma (OS) is the most common primary malignant bone tumour in dogs and human beings, characterised by similar genetic and clinical features. With the aim to define similarities and differences in the biological aspects involved in OS progression, a comparative study was performed to create a model to improve patient outcome.

Methods

First, the expression of microRNAs (miRNAs) belonging to the cluster miR-106b-25 (miR-106b, miR-25 and miR-93-5p) in human and canine OS tissue was compared.

Results

miR-25 and miR-106b presented a variable expression not significantly different from the corresponding normal bone, while miR-93-5p expression was increased in all OS specimens, with higher levels in the canine subset compared with human. Accordingly, its target p21 presented a weaker and less homogeneous immunostaining distribution in the canine group. Given the high expression of miR-93-5p in all OS specimens, the functional response of human 143B and canine DAN OS cells to miRNA inhibition was evaluated. Although p21 expression increased after miR-93-5p inhibition both at mRNA and protein level, a more significant cell response in terms of proliferation and apoptosis was seen in canine OS cells.

Conclusions

In conclusion, canine OS tissue and cell line presented higher expression levels of miR-93-5p than human OS. In addition, the introduction of miR-93-5p inhibitor caused a cell response in 143B and DAN that differed for the more intense functional impact in the canine OS cell line.

Long non-coding RNA MEG3 functions as a competing endogenous RNA of miR-93 to regulate bladder cancer progression via PI3K/AKT/mTOR pathway

BACKGROUND

Maternally expressed gene 3 (MEG3) is a long non-coding RNA (lncRNA) and involved in progression of various human tumors. However, its underlying regulatory mechanism in tumorigenesis of bladder cancer (BC) remains unclear. To demonstrate effects of MEG3 on BC cell proliferation and elaborate its regulatory mechanism in BC.

METHODS

Aberrant expressions of MEG3 and miR-93-5p were induced by cell transfection. The mRNA and protein expression were analyzed using qRT-PCR and western blot. Cell proliferation was examined by CCK-8 assay and EdU staining. The targeted regulation effect of MEG3 on miR-93-5p was confirmed by luciferase reporter assay. The number of LC3 punctated cells was detected by immunofluorescence. Xeno-graft mouse model was constructed for in vivo validation.

RESULTS

MEG3 was down-regulated with increased expression of miR-93-5p in BC cells and tissues. Luciferase reporter assay showed that miR-93-5p was a direct target of MEG3 and was negatively regulated by MEG3. MEG3 overexpression inhibited cell proliferation and the expression of proliferation-, apoptosis- and autophagy-related proteins. The activation of PI3K/AKT/mTOR pathway was also suppressed with elevated cell apoptosis. miR-93-5p overexpression counteracted these results. In vivo experiments, we confirmed that miR-93-5p overexpression reversed the MEG3 overexpression-mediated suppression on tumor growth and protein expression.

CONCLUSIONS

lncRNA MEG3 could function as a competing endogenous RNA of miR-93 to regulate the tumorigenesis of BC via PI3K/AKT/mTOR pathway. The present research provided a new perspective to understanding the pathogenic mechanism of BC, and an effective therapeutic target for BC.

Tanshinone I induces apoptosis and protective autophagy in human glioblastoma cells via a reactive oxygen species‑dependent pathway

Glioma is the most common primary malignancy of the central nervous system and is associated with high mortality rates. Despite the available treatment options including surgery, radiotherapy and chemotherapy, the median patient survival rate is low. Therefore, the development of novel anticancer agents for the treatment of glioma is urgently required. Tanshinone I (TS I) is a tanshinone compound that is isolated from Danshen. Accumulating evidence indicates that TS I exhibits antiproliferative activity in a variety of cancer types. However, the role of TS I and its mechanism of action in human glioma remain to be elucidated. In the present study, the anticancer potential of TS I against human glioma U87 MG cells was investigated. The results indicated that TS I exerted a potential cytotoxic effect on human glioma U87 MG cells. TS I was found to induce cell proliferation, inhibition, cell cycle arrest, apoptosis and autophagy in U87 MG cells. Mechanistic experiments indicated that TS I activated endoplasmic reticulum (ER) stress and inhibited AKT signaling and apoptosis in human glioma U87 MG cells. Furthermore, the present study demonstrated that TS I induced protective autophagy in U87 MG cells. Additionally, ER stress and AKT signal-mediated apoptosis and protective autophagy were found to be induced by TS I via intracellular reactive oxygen species accumulation. The results of the present study demonstrated that TS I may be a potential anticancer drug candidate that may be of value in the treatment of human glioma.

miR-762 Promotes Malignant Development of Head and Neck Squamous Cell Carcinoma by Targeting PHLPP2 and FOXO4

Background

Head and neck squamous cell carcinoma (HNSCC) is among the most common malignant tumors worldwide. This study, investigated the role of microRNA (miR)-762 in regulating HNSCC progression.

Materials and methods

The expression levels of miR-762 in HNSCC tissues were measured by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Statistical analyses were performed to investigate the association of miR-762 with clinicopathological features in patients with HNSCC. Cell proliferation and migration were examined by cell counting (CCK-8) and IncuCyte assays. Target genes of miR-762 were screened using bioinformatics tools and microarrays, and confirmed using a luciferase activity reporter assay, qRT-PCR and Western blot analysis. Recuse experiments were performed to detect whether target genes mediated the effects of miR-762 on HNSCC cells. The in vivo effects of miR-762 were verified using tumor xenografts.

Results

HNSCC clinical specimens showed high expression levels of miR-762, which positively correlated with tumor-node-metastasis (TNM) stage and poor prognosis of HNSCC. miR-762 overexpression promoted the proliferation and migration of HNSCC cells in vitro. In addition, overexpression of miR-762 upregulated the expression of phosphorylated AKT (p-AKT) and mesenchymal markers (N-cadherin and vimentin), but suppressed epithelial marker (E-cadherin) expression. miR-762 also promoted HNSCC tumor growth in vivo. PH domain and leucine-rich repeat protein phosphatase 2 (PHLPP2) and Forkhead box O4 (FOXO4) were direct target genes of miR-762. HNSCC tissues had low expression levels of PHLPP2 and FOXO4, showing a negative correlation with miR-762 expression. Moreover, silencing of PHLPP2 and FOXO4 mimicked the tumor-promotive effects of miR-762 on HNSCC cells. Notably, overexpression of PHLPP2 and FOXO4 abolished the pro-tumoral function of miR-762 on cell proliferation and migration.

Conclusion

miR-762 promotes HNSCC progression by targeting PHLPP2 and FOXO4. Therefore, miR-762 might be a potential diagnostic or therapeutic target for HNSCC.

Expression of Clusterin suppresses Cr(VI)-induced premature senescence through activation of PI3K/AKT pathway

Our group found that long-term low-dose exposure to hexavalent chromium [Cr(VI)] in L-02 hepatocytes resulted in premature senescence, which accompanied by the increased expression of Clusterin (CLU), but the functional role of CLU in premature senescence has never been explored. In the present study, the CLU overexpressed or silenced L-02 hepatocytes were established by lentiviral vector transfection. Cell viability assay, cell cycle analysis, western blotting, plate clone formation assay, and confocal microcopy were performed. The results indicated that Cr(VI)-induced premature senescence was associated with phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) pathway inhibition, and high expression of CLU in the senescent cells exerted its functional role of promoting cell proliferation. CLU could complex with eukaryotic translation initiation factor 3 subunit I (EIF3I) and prevent its degradation, leading to the increase of AKT activity in Cr(VI)-exposed senescent hepatocytes. Blockage of the PI3K/AKT pathway with its inhibitor LY294002 eliminated the inhibitory effect of CLU on Cr(VI)-induced premature senescence. We concluded that high expression of CLU suppressed Cr(VI)-induced premature senescence through activation of PI3K/AKT pathway, which will provide the experimental basis for the study of Cr(VI)-induced liver cancer, especially for the elucidation of the mechanism of liver cancer cells escaping from senescence.

PHLPP2 as a novel metastatic and prognostic biomarker in non-small cell lung cancer patients

Background

PH domain and leucine‐rich repeat protein phosphatase 2 (PHLPP2) has been reported to be a potent tumor suppressor in many human cancers. However, PHLPP2 has not been fully researched as a putative clinical prognostic biomarker of lung cancer.

Methods

The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases including data on 1383 non‐small cell lung cancer (NSCLC) patients were used to determine PHLPP2 expression. PHLPP2 expression was then examined by immunohistochemistry, and its clinical significance analyzed in 134 NSCLC patients, including 73 patients with adenocarcinoma and 81 with squamous cell carcinoma.

Results

We found PHLPP2 expression to be less pronounced in NSCLC tissue samples than that in nontumoral lung tissues according to data taken from TCGA and GEO datasets; this outcome was further validated by immunohistochemistry assay. The low PHLPP2 expression level was found to be associated with the presence of lymph node metastasis (P = 0.003). Importantly, PHLPP2 was found to be an independent indicator of prognosis for overall (hazard ratio [HR] = 0.520, 95% confidence interval [Cl] = 0.327–0.827; P = 0.006) and disease‐free survival (HR = 0.489, 95% Cl = 0.308–0.775; P = 0.002) in patients with surgically‐resected NSCLC by multivariate analysis.

Conclusion

Taken together, our findings show that PHLPP2 is a robust clinical marker for NSCLC survival and could serve as a potential therapeutic target.

Long non‑coding RNA MEG3 suppresses the growth of glioma cells by regulating the miR‑96‑5p/MTSS1 signaling pathway

Glioma is one of the most common types of tumor of the central nervous system with high mobility and mortality. The prognosis of patients with high-grade glioma is poor. Therefore, it is urgent to develop the therapeutic strategies for the treatment of glioma. Long non-coding RNAs (lncRNAs) have been reported as potential inducers or suppressors of numerous types of tumors including glioma. Previous studies have revealed that lncRNA maternally expressed gene 3 (MEG3) is involved in the initiation and progression of cancer; however, the underlying mechanisms remain unclear. In the present study, MEG3 was downregulated in glioma tissue. In addition, downregulation of MEG3 was observed in human glioma cell lines compared with normal astrocyte cells. Furthermore, overexpressed MEG3 inhibited the proliferation, migration and invasion of glioma cells. Additionally, microRNA-96-5p (miR-96-5p) was a promising target of MEG3, and the promoting effects of miR-96-5p on cell growth and metastasis could be reversed by upregulated MEG3. Metastasis suppressor 1 (MTSS1) was predicted as the putative target of miR-96-5p, and its expression was restored by MEG3. In summary, the present data provided novel insight into the roles of MEG3 in glioma, and MEG3/miR-96-5p/MTSS1 signaling could be a promising therapeutic target for the treatment of patients with glioma.

Emerging roles of microRNAs in regulating the mTOR signaling pathway during tumorigenesis

The mammalian target of rapamycin (mTOR) is a large Ser/Thr protein kinase that belongs to the phosphoinositide 3-kinase (PI3K) family and mediates various physiological and pathological processes, especially cell proliferation, protein synthesis, autophagy, and cancer development. The mTOR expression is transient and tightly regulated in normal cells, but it is overactivated in cancer cells. Recently, several studies have indicated that microRNAs (miRNAs) play a critical role in the regulation of mTOR and mTOR-associated processes, some acting as inhibitors and the others as activators. Although it is still in infancy, the strategy of combining both miRNAs and mTOR inhibitors might provide an approach to selectively sensitizing tumor cells to chemotherapy-induced DNA damage and subsequently attenuating the tumor cell growth and apoptosis.

Glioma stem cells-derived exosomal miR-26a promotes angiogenesis of microvessel endothelial cells in glioma

BACKGROUND

Cancer stem cells (CSCs), which are involved in cancer initiation and metastasis, could potentially release exosomes that mediate cellular communication by delivering microRNAs (miRNAs). Based on the role of miR-26a in angiogenesis of glioma, our study was performed to investigate whether glioma stem cells (GSCs)-derived exosomes containing miR-26a could exert effects on angiogenesis of microvessel endothelial cells in glioma, in order to provide a new therapeutic RNA vehicle for glioma therapies.

METHODS

The expression of miR-26a and PTEN in glioma was quantified and the interaction among miR-26a, PTEN and PI3K/Akt signaling pathway was examined. Next, a series of gain- and loss-of function experiments were conducted to determine the role of miR-26a in angiogenesis of human brain microvascular endothelial cells (HBMECs). Subsequently, HBMECs were exposed to exosomes derived from GSCs with the gain-/loss-of-function of miR-26a. Finally, the effect of exosomal miR-26a on angiogenesis of HBMECs was assessed both in vitro and in vivo.

RESULTS

The results revealed that PTEN was down-regulated, while miR-26a was up-regulated in glioma. miR-26a activated the PI3K/Akt signaling pathway by targeting PTEN. Restored miR-26a promoted proliferation, migration, tube formation, and angiogenesis of HBMECs in vitro. In addition, GSCs-derived exosomes overexpressing miR-26a contributed to enhanced proliferation and angiogenesis of HBMECs in vitro through inhibition of PTEN. The angiogenic effects of GSCs-derived exosomes overexpressing miR-26a in vivo were consistent with the above-mentioned in vitro findings.

CONCLUSION

Collectively, our study demonstrates that GSCs-derived exosomal miR-26a promotes angiogenesis of HBMECs, highlighting an angiogenic role of miR-26a via exosomes.

miR-25-3p promotes glioma cell proliferation and migration by targeting FBXW7 and DKK3

MicroRNAs (miRs) serve important roles in glioma. However, the underlying molecular mechanism of miR-25 in glioma progression remains largely unknown; therefore, it was investigated in the present study. RT-qPCR analysis revealed that miR-25 expression levels were markedly increased in human glioma tissue and glioma cell lines compared with normal brain tissues and normal human astrocytes, respectively. miR-25 upregulation exhibited an association with glioma progression, and the knockdown of miR-25 significantly inhibited glioma cell proliferation and migration. F-box and WD repeat domain containing 7 (FBXW7) and dickkopf WNT signaling pathway inhibitor 3 (DKK3) were identified as target genes of miR-25. FBXW7 and DKK3 expression levels were significantly downregulated in glioma tissue samples compared with normal brain tissue, and their expression levels were negatively regulated by miR-25 expression in glioma cells. Furthermore, inhibition of FBXW7 and DKK3 expression suppressed the miR-25-induced effects on glioma cell proliferation and migration. The findings of the present study suggest that miR-25 may promote glioma cell proliferation and migration by inhibiting the expression of FBXW7 and DKK3. Therefore, miR-25 may serve as a promising molecular target for the treatment of glioma.

MIR93 (microRNA -93) regulates tumorigenicity and therapy response of glioblastoma by targeting autophagy

Macroautophagy/autophagy is a natural intracellular process that maintains cellular homeostasis and protects cells from death under stress conditions. Autophagy sustains tumor survival and growth when induced by common cancer treatments, including IR and cytotoxic chemotherapy, thereby contributing to therapeutic resistance of tumors. In this study, we report that the expression of MIR93, noted in two clinically relevant tumor subtypes of GBM, influenced GSC phenotype as well as tumor response to therapy through its effects on autophagy. Our mechanistic studies revealed that MIR93 regulated autophagic activities in GSCs through simultaneous inhibition of multiple autophagy regulators, including BECN1/Beclin 1, ATG5, ATG4B, and SQSTM1/p62. Moreover, two first-line treatments for GBM, IR and temozolomide (TMZ), as well as rapamycin (Rap), the prototypic MTOR inhibitor, decreased MIR93 expression that, in turn, stimulated autophagic processes in GSCs. Inhibition of autophagy by ectopic MIR93 expression, or via autophagy inhibitors NSC (an ATG4B inhibitor) and CQ, enhanced the activity of IR and TMZ against GSCs. Collectively, our findings reveal a key role for MIR93 in the regulation of autophagy and suggest a combination treatment strategy involving the inhibition of autophagy while administering cytotoxic therapy. Abbreviations: ACTB: actin beta; ATG4B: autophagy related 4B cysteine peptidase; ATG5: autophagy related 5; BECN1: beclin 1; CL: classical; CQ: chloroquine diphosphate; CSCs: cancer stem cells; GBM: glioblastoma; GSCs: glioma stem-like cells; HEK: human embryonic kidney; IB: immunoblotting; IF: immunofluorescent staining; IR: irradiation; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MES: mesenchymal; MIR93: microRNA 93; MIRC: a control miRNA; miRNA/miR: microRNA; MTOR: mechanistic target of rapamycin kinase; NSC: NSC185085; PN: proneural; qRT-PCR: quantitative reverse transcription-polymerase chain reaction; Rap: rapamycin; SQSTM1/p62: sequestosome 1; TCGA: the cancer genome atlas; TMZ: temozolomide; WT: wild type; ZIP93: lentiviral miRZIP targeting MIR93; ZIPC: lentiviral miRZip targeting control miRNA.

Expression Levels of microRNAs miR-93 and miR-200a in Pancreatic Adenocarcinoma with Special Reference to Differentiation and Relapse-Free Survival

OBJECTIVES

Protein levels of the transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2) and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) have been proposed as prognostic factors in pancreatic ductal adenocarcinomas (PDACs). These cellular redox-state-regulating enzymes are targeted by several microRNAs, including miR-93 and miR-200a.

METHODS

We assessed mRNA levels of Nrf2 and Keap1 and tissue expression of miR-93 and miR-200a in 51 patients with surgically treated PDAC. Expression levels were separately measured in malignant cells and adjacent benign cells.

RESULTS

Keap1 and Nrf2 mRNA expression levels in cancer cells were lower than in adjacent benign tissue (Wilcoxon's test; p = 0.0015 and p = 0.000032, respectively). Conversely, miR-93 expression was higher in cancer cells than in adjacent benign tissue (p = 0.00082). Low levels of miR-93 and miR-200a in cancer cells were associated with poorer differentiation (p = 0.004 and p = 0.002, respectively). In univariate survival analysis, benign-tissue levels of miR-200a above the median predicted better relapse-free survival (RFS) (p = 0.045).

CONCLUSIONS

High miR-93 and miR-200a levels in cancer cells of PDAC were associated with better differentiation, and miR-200a expression in benign tissue with excellent RFS. Keap1 and Nrf2 mRNA levels showed prominent down-regulation in cancerous versus benign tissue, but they were not associated with disease aggressiveness or outcome.

Yak OXGR1 promotes fibroblast proliferation via the PI3K/AKT pathways

Oxoglutarate receptor 1 (OXGR1), as one of the intermediates in G protein-coupled receptors (GPCRs), plays a crucial role in the citric acid cycle receptor of α-ketoglutarate and metabolism. GPCR can control the cell proliferation by regulating the downstream signaling of G protein signaling pathways. The PI3K/AKT pathway transmits the downstream signals of GPCRs and receptor tyrosine kinases. However, the specific role of OXGR1 promoting cell proliferation and differentiation are still unknown. In current study, the over-expression vector and knockdown sequence of yak OXGR1 were transfected into yak fibroblasts, and the effects were detected by a series of assays. The results revealed that OXGR1 expression in yak lung parenchyma tissue was significantly higher than that of other tissues. In yak fibroblasts, the upregulated expression of OXGR1 resulted in activating the PIK3CG (downstream signal) of the PI3K/AKT1 pathway that can upregulated the expression of proliferation genes ( CDK1, PCNA, and CyclinD1) and promote cell proliferation. Conversely, the downregulated expression of OXGR1 inhibited cell proliferation via PI3K/AKT1 pathway. Cell cycle and cell proliferation assays demonstrated that over-expression of OXGR1 can enhanced the DNA synthesis and promoted yak fibroblasts proliferation. While the conversely, knockdown of OXGR1 can decreased DNA synthesis and inhibited cell proliferation. These results illustrated that changes of OXGR1 expression can trigger the fibroblasts proliferation via PI3K/AKT signaling pathway, which indicating that OXGR1 is a novel regulator for cell proliferation and differentiation. Furthermore, these results provide evidence supporting the functional role of GPCRs-PI3K-AKT1 and OXGR1 in cell proliferation.

Neferine inhibits proliferation, migration and invasion of U251 glioma cells by down-regulation of miR-10b

BACKGROUND

Glioma is a common brain tumor, which is a serious threat to the life and health of human with high mortality rate. Recently, neferine (NEF) has been reported to play an important role in various cancers. In the study, we aimed to investigate the effect of NEF on human glioma cell line U251.

METHODS

U251 cells were pre-treated with different concentrations of NEF, and then CCK-8, BrdU, flow cytometry and transwell assays were used to test cell proliferation, apoptosis, migration and invasion. Subsequently, the expression vectors of miR-10b mimic and miR-10b inhibitor were transfected into U251 cells, and the relative expression of miR-10b was examined by qRT-PCR. The main proteins of CyclinD1/p53/p16, pro-Caspase-3/-9, cleaved-Caspase-3/-9, MMP-9, Vimentin, PTEN/PI3K/AKT and p38MAPK signal pathways were determined by western blot assay.

RESULTS

NEF significantly suppressed cell proliferation, and induced apoptosis, as well as regulated CyclinD1, p53, p16 and cleaved-Caspase-3/-9 expressions in U251 cells. Moreover, NEF inhibited cell migration, invasion and decreased MMP-9 and Vimentin expression in U251 cells. Additionally, miR-10b expression was down-regulated in NEF-stimulated cells, and overexpression of miR-10b reversed the regulatory effects of NEF on U251 cells proliferation, migration, invasion and apoptosis. Additionally, we found that PTEN was a direct target of miR-10b in U251 cells. Besides, NEF deactivated PTEN/PI3K/AKT and p38MAPK signal pathways by down-regulation of miR-10b in U251 cells.

CONCLUSIONS

These results suggested that NEF exerted anti-tumor effect by down-regulation of miR-10b and deactivation of PTEN/PI3K/AKT and p38MAPK signal pathways in glioma cells. These findings might provide a novel therapeutic strategy for glioma.

Molecular mechanism and role of microRNA-93 in human cancers: A study based on bioinformatics analysis, meta-analysis, and quantitative polymerase chain reaction validation

INTRODUCTION

Currently, studies have shown that microRNA-93 (miR-93) can be an oncogene or a tumor suppressor in different kinds of cancers. The role of miR-93 in human cancers is inconsistent and the underlying mechanism on the aberrant expression of miR-93 is complicated.

METHODS

We first conducted gene enrichment analysis to give insight into the prospective mechanism of miR-93. Second, we performed a meta-analysis to evaluate the clinical value of miR-93. Finally, a validation test based on quantitative polymerase chain reaction (qPCR) was performed to further investigate the role of miR-93 in pan-cancer.

RESULTS

Gene Ontology (GO) enrichment analysis results showed that the target genes of miR-93 were closely related to transcription, and MAPK1, RBBP7 and Smad7 became the hub genes. In the diagnostic meta-analysis, the overall sensitivity, specificity, and area under the curve were 0.76 (0.64-0.85), 0.82 (0.64-0.92), and 0.85 (0.82-0.88), respectively, which suggested that miR-93 had excellent performance on the diagnosis for human cancers. In the prognostic meta-analysis, dysregulated miR-93 was found to be associated with poor OS in cancer patients. In the qPCR validation test, the serum levels of miR-93 were upregulated in breast cancer, breast hyperplasia, lung cancer, chronic obstructive pulmonary disease, nasopharyngeal cancer, hepatocellular cancer, gastric ulcer, endometrial cancer, esophageal cancer, laryngeal cancer, and prostate cancer compared with healthy controls.

CONCLUSIONS

miR-93 could act as an effective diagnostic and prognostic factor for cancer patients. Its clinical value for cancer early diagnosis and survival prediction is promising.

MCL1 gene silencing promotes senescence and apoptosis of glioma cells via inhibition of the PI3K/Akt signaling pathway

Glioma is known to be the most prevalent primary brain tumor. In recent years, there has been evidence indicating myeloid cell leukemia-1 (MCL1) plays a role in brain glioblastoma. Therefore, the present study was conducted with aims of exploring the ability of MCL1 silencing to influence glioma cell senescence and apoptosis through the mediation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway. Glioma and tumor-adjacent tissues were collected in order to detect the presence of higher levels of MCL1 protein expression. Next, the mRNA and protein expression of MCL1, PI3K, Akt, B cell lymphoma 2 (Bcl2), Bcl2-associated X (Bax), B lymphoma Mo-MLV insertion region 1 homolog (Bmi-1), and phosphatase and tensin homolog (PTEN) were determined. Cell counting kit-8 assay was applied to detect cell proliferation, β-galactosidase staining for cell senescence, and flow cytometry for cell cycle entry and apoptosis. Initially, the results revealed higher positive expression rate of MCL1 protein, increased mRNA and protein expression of MCL1, PI3K, Akt, Bmi-1, and Bcl-2 and decreased that of Bax and PTEN in human glioma tissues. The silencing of MCL1 resulted in a decrease in mRNA and protein expression of PI3K, Akt, Bmi-1, and Bcl-2 and an increase in Bax and PTEN expressions in glioma cells. Moreover, silencing of MCL1 also inhibited cell proliferation and cell cycle entry in glioma cells, and promoted glioma cell senescence and apoptosis. In conclusion, the aforementioned results collectively suggested that the silencing of MCL1 promotes senescence and apoptosis in glioma cells through inhibiting the PI3K/Akt signaling pathway. Thus, decreasing the expression of MCL1 might have therapeutic functions in glioma. © 2018 IUBMB Life, 71(1):81-92, 2019.

Baicalin, the major component of traditional Chinese medicine Scutellaria baicalensis induces colon cancer cell apoptosis through inhibition of oncomiRNAs

Colorectal cancer (CRC) is among the most frequently occurring cancers worldwide. Baicalin is isolated from the roots of Scutellaria baicalensis and is its dominant flavonoid. Anticancer activity of baicalin has been evaluated in different types of cancers, especially in CRC. However, the molecular mechanisms underlying the contribution of baicalin to the treatment of CRC are still unknown. Here, we confirmed that baicalin can effectively induce and enhance apoptosis in HT-29 cells in a dose-dependent manner and suppress tumour growth in xenografted nude mice. We further performed a miRNA microarray analysis of baicalin-treated and untreated HT-29 cells. The results showed that a large number of oncomiRs, including miR-10a, miR-23a, miR-30c, miR-31, miR-151a and miR-205, were significantly suppressed in baicalin-treated HT-29 cells. Furthermore, our in vitro and in vivo studies showed that baicalin suppressed oncomiRs by reducing the expression of c-Myc. Taken together, our study shows a novel mechanism for anti-cancer action of baicalin, that it induces apoptosis in colon cancer cells and suppresses tumour growth by reducing the expression of c-Myc and oncomiRs.

DNA methylation and FoxO3a regulate PHLPP1 expression in chondrocytes

The protein phosphatase Phlpp1 is an essential enzyme for proper chondrocyte function. Altered Phlpp1 levels are associated with cancer and degenerative diseases such as osteoarthritis. While much is known about the post-transcriptional mechanisms controlling Phlpp1 levels, transcriptional regulation of the Phlpp1 gene locus is underexplored. We previously showed that CpG methylation of the PHLPP1 promoter is lower in osteoarthritic cartilage than in normal cartilage, and indirectly correlates with gene expression. Here we further defined the effects of DNA methylation on PHLPP1 promoter activity in chondrocytes. We cloned a 1791 bp fragment of the PHLPP1 promoter (-1589:+202) and found that the first 500 bp were required for maximal promoter activity. General methylation of CpG sites within this fragment significantly blunts transcriptional activity, whereas site-specific methyltransferases HhaI or HpaII decrease transcriptional activation by approximately 50%. We located putative FoxO consensus sites within the PHLPP1 promoter region. Inhibition of DNA methylation by incorporation of 5-azacytidine increases Phlpp1 mRNA levels, but FoxO inhibition abolishes this induction. To determine which FoxO transcription factor mediates Phlpp1 expression, we performed overexpression and siRNA-mediated knock down experiments. Overexpression of FoxO3a, but not FoxO1, increases Phlpp1 levels. Likewise, siRNAs targeting FoxO3a, but not FoxO1, diminished Phlpp1 levels. Last, FoxO inhibition increases glycosaminoglycan staining of cultured chondrocytes and leads to concomitant increases in FGF18 and HAS2 expression. Together, these data demonstrate that CpG methylation and FoxO3a regulate PHLPP1 expression.

The emerging roles of the polycistronic miR-106b∼25 cluster in cancer - A comprehensive review

MicroRNAs (miRNAs) are short, non-coding RNA molecules that regulate gene expression at the post-transcriptional level by inhibiting translation and decreasing the stability of the targeted transcripts. Over the last two decades, miRNAs have been recognized as important regulators of cancer cell biology, acting either as oncogenes or tumor suppressors. The polycistronic miR-106b∼25 cluster, located within an intron of MCM7 gene, consists of three highly conserved miRNAs: miR-25, miR-93 and miR-106b. A constantly growing body of evidence indicates that these miRNAs are overexpressed in numerous human malignancies and regulate multiple cellular processes associated with cancer development and progression, including: cell proliferation and survival, invasion, metastasis, angiogenesis and immune evasion. Furthermore, recent studies revealed that miR-106b∼25 cluster miRNAs modulate cancer stem cells characteristics and might promote resistance to anticancer therapies. In light of these novel discoveries, miRNAs belonging to the miR-106b∼25 cluster have emerged as key oncogenic drivers as well as potential biomarkers and plausible therapeutic targets in different tumor types. Herein, we comprehensively review novel findings on the roles of miR-106b∼25 cluster in human cancer, and provide a broad insight into the molecular mechanisms underlying its oncogenic properties.

miR-93 Promotes the Growth and Invasion of Prostate Cancer by Upregulating Its Target Genes TGFBR2, ITGB8, and LATS2

This study aimed to evaluate the effects of miR-93 on the growth and invasiveness of prostate cancer (PC) cells (PCCs). Real-time PCR was carried out to detect the expression of miR-93 in the PC tissues and cell lines. The adjacent normal tissues served as controls. For in vitro experiments, methyl thiazolyl tetrazolium, clone formation, tumor cell invasion assays, and western blot analysis (WBA) were performed to confirm the variations in the proliferation and invasiveness of PCCs, prior and subsequent to transfection with an miR-93 antisense oligonucleotide (ASO), which blocks miR-93 binding to its target. Furthermore, the effect of miR-93 on the proliferation of PCCs was examined. Finally, the expression levels of the target genes of miR-93 were determined by WBA. miR-93 expression was higher in PC tissues than in the adjacent normal tissues, and a reduction in the miR-93 level remarkably inhibited the proliferation and invasiveness of PCCs. Moreover, miR-93 enhanced the expression of its target genes TGFΒR2, ITGB8, and LATS2. The results of this study suggest that miR-93 may promote the proliferation and invasion of PCCs by upregulating its target genes TGFBR2, ITGB8, and LATS2.

Exogenous H2 S exerts biphasic effects on porcine mammary epithelial cells proliferation through PI3K/Akt-mTOR signaling pathway

This study aimed to investigate the effects of exogenous H₂ S on the proliferation of porcine mammary gland epithelial cells (PMECs) and explore the underlying mechanisms. We found that exposure of PMECs to NaHS, at concentrations ranging from 10 to 200 µM, stimulated cell proliferation. However, high concentration of NaHS (600 µM) inhibited PMECs proliferation. Accordingly, 10 µM NaHS significantly increased the percentage of cells undergoing DNA replication, elevated the mRNA and/or protein expression of Cyclin A2, Cyclin D1/3, Cyclin E2 and PCNA, and decreased p21 mRNA expression. In contrast, 600 µM NaHS elicited the opposite effects to that of 10 µM NaHS. In addition, PI3 K/Akt and mTOR signaling pathways were activated or inhibited in response to 10 or 600 µM NaHS, respectively. Furthermore, the promotion of PMECs proliferation, the change of proliferative genes expression, and the activation of mTOR signaling pathway induced by 10 µM NaHS were effectively blocked by PI3 K inhibitor Wortmannin. Similarly, inhibition of mTOR with Rapamycin totally abolished the 10 µM NaHS-induced stimulation of PMECs proliferation and alteration of proliferative genes expression, with no influence on PI3 K/Akt signaling pathway. Moreover, constitutive activation of Akt pathway via transfection of Akt-CA completely eliminated the inhibition of PMECs proliferation and mTOR signaling pathway, and the change of proliferative genes expression induced by 600 µM NaHS. In conclusion, our findings provided evidence that exogenous H₂ S supplied by NaHS exerted biphasic effects on PMECs proliferation, with stimulation at lower doses and suppression at high dose, through the intracellular PI3 K/Akt-mTOR signaling pathway.

Identification of microRNAs associated with glioma diagnosis and prognosis

The sensitivity and specificity of microRNAs (miRNAs) for diagnosing glioma are controversial. We therefore performed a meta-analysis to systematically identify glioma-associated miRNAs. We initially screened five miRNA microarray datasets to evaluate the differential expression of miRNAs between glioma and normal tissues. We next compared the expression of the miRNAs in different organs and tissues to assess the sensitivity and specificity of the differentially expressed miRNAs in the diagnosis of glioma. Finally, pathway analysis was performed using GeneGO. We identified 27 candidate miRNAs associated with glioma initiation, progression, and patient prognosis. Sensitivity and specificity analysis indicated miR-15a, miR-16, miR-21, miR-23a, and miR-9 were up-regulated, while miR-124 was down-regulated in glioma. Ten signaling pathways showed the strongest association with glioma development and progression: the p53 pathway feedback loops 2, Interleukin signaling pathway, Toll receptor signaling pathway, Parkinson's disease, Notch signaling pathway, Cadherin signaling pathway, Apoptosis signaling pathway, VEGF signaling pathway, Alzheimer disease-amyloid secretase pathway, and the FGF signaling pathway. Our results indicate that the integration of miRNA, gene, and protein expression data can yield valuable biomarkers for glioma diagnosis and treatment. Indeed, six of the miRNAs identified in this study may be useful diagnostic and prognostic biomarkers in glioma.