Background In recent years, gene expression-based analysis has been used for disease biomarker discovery, providing ways for better diagnosis, leading to improvement of clinical treatment efficacy. This study aimed to explore the role of miR-16-5p and ANLN in breast cancer (BC). Methods Cohort datasets of BC were obtained from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) and analyzed by bioinformatics tools. qRT-PCR and western blotting were applied to validate ANLN and its protein expression. A dual-luciferase reporter assay was used to prove the regulatory relationship of miR-16-5p and ANLN. Finally, MTT, wound healing, Transwell invasion and flow cytometry analyses of the cell cycle and apoptosis were performed to assess cell proliferation, migration, invasion, cell cycle and apoptosis, respectively. Results A total of 195 differentially expressed genes (DEGs) and 50 overlapping microRNAs (miRNAs) were identified. Among these DEGs and miRNAs, ANLN, associated with poor overall survival in BC, overlapped in the GSE29431, GSE42568, TCGA and GEPIA2 databases. Moreover, ANLN was highly expressed, while miR-16-5p was lower in BC cells than in breast epithelial cells. Then, we confirmed that ANLN was directly targeted by miR-16-5p in BC cells. Over-expression of miR-16-5p and knock-down of ANLN remarkably inhibited cell proliferation and migration as well as cell invasion, arrested the cells in G2/M phase and induced apoptosis in BC cells. Conclusions These findings suggest that miR-16-5p restrains proliferation, migration and invasion while affecting cell cycle and promotes apoptosis by regulating ANLN, thereby providing novel candidate biomarkers for the diagnosis and treatment of BC.

Background/Aims: microRNAs are of vital importance in neural development. As a brain-specific miRNA, miR-132 has been well studied in mature neurons. However, its role in neural stem cells (NSCs) remains unclear. In this study, we investigated the role of miR-132 in regulating NSCs proliferation, differentiation and neuronal maturation. Methods: NSCs were obtained from fetal mice spinal cord. Proliferation, cell cycle, cell apoptosis, cell motility were measured through CCK-8, BrdU, AnnexinV-FITC/PI and migration assay respectively. The expression of synaptic proteins and ERK1/2 pathway were detected by western blot. The inactivation of Notch pathway was checked using qPCR. The neurite outgrowth was recorded using Image J software and Neuron J software. Dendritic length was further analyzed through sholl analysis. Fate determination of NSCs, developmental synapse formation was assessed by immunostaining. Results: miR-132 negatively regulated NSCs proliferation by affecting the cell cycle and promoting apoptosis. Inactivated Notch-Hes1pathway was observed in miR-132 overexpression cells. miR-132 was significantly increased in differentiating NSCs following activation of ERK1/2 pathway. miR-132 could impair neuronal differentiation but promote glial cell differentiation by regulating Mecp2 expression. miR-132 was implicated in neurite outgrowth but slightly inhibited postsynaptic PSD-95 expression. The differentiated neurons exhibited normal electrophysiological characteristics, and already interacted with other neurons to form synaptic-like structures. Conclusion: miR-132 was demonstrated as a negative regulator for NSCs self-renewal, neuronal differentiation but promoted glial cell differentiation and neurite outgrowth.

Background/Aims: Serine/threonine kinase 35 (STK35) may be associated with Parkinson disease and human colorectal cancer, but there have been no reports on the expression levels or roles of STK35 in osteosarcoma. Methods: STK35 mRNA expression was determined in osteosarcoma and bone cyst tissues by real-time PCR. Cell proliferation and apoptosis were assessed by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis, respectively. Results: STK35 was up-regulated in osteosarcoma tissues as indicated by analyzing publicly available expression data (GEO dataset E-MEXP-3628) and real-time PCR analysis on our own cohort. We subsequently investigated the effects of STK35 knockdown on two osteosarcoma cell lines, MG63 and U2OS. STK35 knockdown inhibited the growth of osteosarcoma cells in vitro and in xenograft tumors. Meanwhile, STK35 knockdown enhanced apoptosis. Expression of the active forms and the activity of two major executioner caspases, caspase 3 and caspase 7, were also increased in osteosarcoma cells with STK35 silenced. Additionally, Gene Set Enrichment Analysis (GSEA) identified that the JAK/STAT signaling pathway was positively correlated with STK35 expression. The mRNA expression of STK35 was repressed by STAT3 small interfering RNA (siRNA), but not by siRNA of STAT4, STAT5A or STAT6. A luciferase reporter assay further demonstrated that STAT3 transcriptionally regulated STK35 expression. A chromatin immunoprecipitation (ChIP) assay confirmed the direct recruitment of STAT3 to the STK35 promoter. The promotion effects of STAT3 knockdown on cell apoptosis were partially abolished by STK35 overexpression. Furthermore, STK35 mRNA expression was positively correlated with STAT3 mRNA expression in osteosarcoma tissues by Pearson correlation analysis. Conclusions: These results collectively reveal that STAT3 regulates the transcription of STK35 in osteosarcoma. STK35 may exert an oncogenic role in osteosarcoma.