PurposeThis study was designed to explore how miR-145 regulates the mTOR signaling pathway in invasive pituitary adenoma (IPA) by targeting AKT3.MethodsA total of 71 cases of IPA tissues and 66 cases of non-IPA tissues were obtained in this study. In vitro, the IPA cells were assigned into blank control, empty plasmid, miR-145 mimic, miR-145 inhibitor, miR-145 mimic + rapamycin, miR-145 inhibitor + rapamycin and rapamycin groups. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting were performed to detect the protein expressions of PI3K, AKT3, mTOR mRNA and the mRNA expression of miR-145 both in vivo and in vitro. Additionally, the S6K and RPS6 mRNA and protein expressions as well as the relative phosphorylation levels were determined in vitro. MTT assay, flow cytometry and transwell assay were used to testify the cell proliferation, apoptosis and invasion ability, respectively.ResultsThe IPA tissues exhibited significantly lower expression of miR-145 but higher PI3K, AKT3 and mTOR mRNA and protein expressions when compared with the non-IPA tissues. Compared with the blank control and empty plasmid groups, the miR-145 mimic group showed significantly decreased PI3K, AKT3, mTOR, S6K and RPS6 mRNA and protein expressions as well as phosphorylation levels; besides, the IPA cell proliferation, migration and invasion ability were strongly inhibited, accompanied with the increased number of apoptotic cells. In the miR-145 inhibitor group, the PI3K, AKT3, mTOR, S6K and RPS6 mRNA and protein expressions as well as the phosphorylation levels were significantly increased; cell proliferation, migration and invasion ability were remarkably elevated, accompanied with reduced apoptotic cell number.ConclusionThe study demonstrates that miR-145 inhibits the mTOR signaling pathway to suppress the IPA cell proliferation and invasion and promotes its apoptosis by targeting AKT3.

Long non-coding RNAs (lncRNAs) comprise an integral part of the eukaryotic transcriptome. Alongside proteins, lncRNAs modulate lncRNA-based gene signatures of unstable transcripts, play a crucial role as antisense lncRNAs to control intracellular homeostasis and are implicated in tumorigenesis. However, the role of genomic instability-associated lncRNAs in low-grade gliomas (LGG) has not been fully explored. In this study, lncRNAs expression and somatic mutation profiles in low-grade glioma genome were used to identify eight novel mutant-derived genomic instability-associated lncRNAs including H19, FLG-AS1, AC091932.1, AC064875.1, AL138767.3, AC010273.2, AC131097.4 and ISX-AS1. Patients from the LGG gene mutagenome atlas were grouped into training and validation sets to test the performance of the signature. The genomic instabilityassociated lncRNAs signature (GILncSig) was then validated using multiple external cohorts. A total of 59 novel genomic instability-associated lncRNAs in LGG were used for least absolute shrinkage and selection operator (Lasso), single and multifactor Cox regression analysis using the training set. Furthermore, the independent predictive role of risk features in the training and validation sets were evaluated through survival analysis, receiver operating feature analysis and construction of a nomogram. Patients with IDH1 mutation status were grouped into two different risk groups based on the GILncSig score. The low-risk group showed a relatively higher rate of IDH1 mutations compared with patients in the high-risk group. Furthermore, patients in the lowrisk group had better prognosis compared with patients in the high-risk group. In summary, this study reports a reliable prognostic prediction signature and provides a basis for further investigation of the role of lncRNAs on genomic instability. In addition, lncRNAs in the signature can be used as new targets for treatment of LGG.

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Background: N6-methyladenosine (m6A) RNA methylation is an important epigenetic modification affecting alternative splicing (AS) patterns of genes to regulate gene expression. AS drives protein diversity and its imbalance may be an important factor in tumorigenesis. However, the clinical significance of m6A RNA methylation regulator-related AS in the tumor microenvironment has not been investigated in low-grade glioma (LGG).Methods: We used 12 m6A methylation modulatory genes (WTAP, FTO, HNRNPC, YTHDF2, YTHDF1, YTHDC2, ALKBH5, YTHDC1, ZC3H13, RBM15, METTL14, and METTL3) from The Cancer Genome Atlas (TCGA) database as well as the TCGA-LGG (n = 502) dataset of AS events and transcriptome data. These data were downloaded and subjected to machine learning, bioinformatics, and statistical analyses, including gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Univariate Cox, the Least Absolute Shrinkage and Selection Operator (LASSO), and multivariable Cox regression were used to develop prognostic characteristics. Prognostic values were validated using Kaplan-Maier survival analysis, proportional risk models, ROC curves, and nomograms. The ESTIMATE package, TIMER database, CIBERSORT method, and ssGSEA algorithm in the R package were utilized to explore the role of the immune microenvironment in LGG. Lastly, an AS-splicing factor (SF) regulatory network was examined in the case of considering the role of SFs in regulating AS events.Results: An aggregate of 3,272 m6A regulator-related AS events in patients with LGG were screened using six machine learning algorithms. We developed eight AS prognostic characteristics based on splice subtypes, which showed an excellent prognostic prediction performance. Furthermore, quantitative prognostic nomograms were developed and showed strong validity in prognostic prediction. In addition, prognostic signatures were substantially associated with tumor immune microenvironment diversity, ICB-related genes, and infiltration status of immune cell subtypes. Specifically, UGP2 has better promise as a prognostic factor for LGG. Finally, splicing regulatory networks revealed the potential functions of SFs.Conclusion: The present research offers a novel perspective on the role of AS in m6A methylation. We reveal that m6A methylation regulator-related AS events can mediate tumor progression through the immune-microenvironment, which could serve as a viable biological marker for clinical stratification of patients with LGG so as to optimize treatment regimens.

Human pituitary adenoma is one of the most common intracranial tumors with an incidence as high as 16.7%. Recent evidence has hinted a relationship between growth factors of pituitary or hypothalamic origin and proliferation of human pituitary adenoma cells. This study explores the effects of small interfering RNA-mediated silencing of basic fibroblast growth factor gene on the proliferation, migration, and invasion of human pituitary adenoma cells. Human pituitary adenoma tissues were collected to obtain human pituitary adenoma cells. The basic fibroblast growth factor silencing interference plasmid was constructed, and the human pituitary adenoma cells were transfected and assigned as basic fibroblast growth factor-small interfering RNA, negative control-small interfering RNA, and blank groups. The quantitative real-time polymerase chain reaction and Western blotting were carried out to detect the expression of basic fibroblast growth factor, pituitary tumor transforming gene, vascular endothelial growth factor, cluster of differentiation 147, and matrix metalloproteinase 9. Cell Counting Kit-8 assay was conducted to observe cell proliferation at 0, 24, 48, and 72 h. Flow cytometry was used to determine cell cycle. Transwell and scratch test were applied to detect the invasion and migration of pituitary adenoma cells. Protein kinase C activity was detected. In comparison with the blank group, the basic fibroblast growth factor-small interfering RNA group showed reduced messenger RNA and protein expression of basic fibroblast growth factor, reduced cell viability at 24, 48, and 72 h, increased cells in G0/G1 stage, declined cells in S and G2/M stages, decreased number of cell migration, shortened migrating distance, reduced protein kinase C activity, and decreased expression of pituitary tumor transforming gene, vascular endothelial growth factor, cluster of differentiation 147, and matrix metalloproteinase 9. However, the negative control-small interfering RNA group had no evident differences in basic fibroblast growth factor expression, cell viability, cell cycle, number of cell migration, migrating distance, protein kinase C activity, and expression of pituitary tumor transforming gene, vascular endothelial growth factor, cluster of differentiation 147, and matrix metalloproteinase 9 compared with the blank group. The study provides evidence that small interfering RNA-mediated silencing of basic fibroblast growth factor gene inhibits the proliferation, migration, and invasion of human pituitary adenoma cells.