Notch1 targeted regulation of mir-224/LRIG2 signaling for the proliferation and apoptosis of cervical cancer cells

miR-224-5p protects dental pulp stem cells from apoptosis by targeting Rac1

Dental pulp stem cells (DPSCs) are reported to be enriched in stem/progenitor cells, however to the best of our knowledge they have yet to be well documented and characterized. In the present study, in order to characterize DPSCs and the effect of microRNAs (miRs/miRNAs) on DPSC properties, a miRNA array was performed between dental periodontal ligament cells (DPLCs) and DPSCs. The results revealed that miR-224-5p (miR-224) was highly expressed in the DPSCs compared with that in the DPLCs. The transfection of DPSCs with an miR-224 inhibitor impaired cell viability. In addition, miR-224 inhibition significantly promoted cell apoptosis in DPSCscompared with the NC group. In silico analysis and a dual-luciferase reporter assay demonstrated that miR-224 targets the 3′-untranslated region of the Rac family small GTPase 1 (Rac1) gene. miR-224 downregulation resulted in the increased expression of Rac1 in DPSCs compared with DPLCs. Furthermore, miR-224 inhibition caused augmented mitogen-activated protein kinase 8, caspase-3, caspase-9 and Fas ligand expression in DPSC, which may be recovered by Rac1 silencing with transfection with short hairpin RNA-Rac1. Furthermore, Annexin V-fluorescein isothiocyanate/propidium iodide flow cytometry indicated that the silencing of Rac1 restored the pro-apoptotic DPSC cell number with miR-224 transfection. Therefore, the results of the present study suggested miR-224 in DPSC serves an important function in protecting cells against apoptosis by downregulating Rac1 expression, and also identified miR-224 as a novel miRNA in regulating the features of DPSC.

MLK3 silence induces cervical cancer cell apoptosis via the Notch-1/autophagy network

Mixed-lineage kinase 3 (MLK3), the mitogen-activated protein kinase kinase kinase (MAP3K), has been recognized as a player in tumorigenesis and oncogenic signalling, yet its detailed functions and signalling in cervical cancer have not been fully elucidated. Here, we identify that cervical cancer cells display higher mRNA and protein levels of MLK3 than normal cervical epithelial squamous cells. In HeLa and SiHa cell, MLK3 knockdown using siRNA remarkably suppressed cell survival and promoted cell apoptosis, with increased expression of the apoptosis-related protein Bax and reduced Bcl-2. Moreover, MLK3 knockdown promoted cell autophagy, demonstrated by increased ratio of autophagy-related proteins LC3II/LC3I and decreased p62 expression in MLK3 depletion cells. Furthermore, MLK3 knockdown remarkably abolished Notch-1 expression in cervical cancer cells. By co-treating Hela cells with MLK3 specific siRNA and pcDNA3.1-Notch-1 overexpression plasmid or autophagy inhibitor 3-MA, we found that MLK3 played its role in cervical cancer cells via the Notch-1/autophagy network. Our results demonstrate the importance of MLK3 in cervical cancer progression via modulating the Notch-1/autophagy network, and suggest that MLK3 is a promising therapeutic target for cervical cancer.

Identification of a nine-miRNA signature for the prognosis of Uveal Melanoma

The present study aims to construct a miRNA-based predictive signature of Uveal melanoma (UM) based on the database of the cancer genome atlas (TCGA). We obtained miRNA expression profiles and clinical information of 80 UM patients from TCGA, and randomly divided them into a training and a testing set. After data processing and forward screening, a total of 204 miRNAs with prognostic value were then examined by the Cox proportional hazard regression model in the training set. Receiver operating curve (ROC) analysis was applied to validate the accuracy of the signature. The biological relevance of putative miRNA target genes was also analyzed using the bioinformatics method. As a result, a linear prognostic model consisting of 9 miRNAs (miR-195, miR-224, miR-365a, miR-365b, miR-452, miR-4709, miR-7702, miR-513c, miR-873) was developed to divide UM patients into a high- and a low-risk group. Patients assigned to the high-risk group had significantly shorter overall survival than those in the low-risk group, which was further confirmed by the Area under curve (AUC) value of 0.858 at 5 year obtained from ROC. Gene Ontology (GO) analysis indicated that predicted target genes of these miRNAs are primarily associated with the modulation of protein expression and function, such as the activity of ubiquitin protein ligase and protein kinase. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that these genes were involved in multiple signaling pathways linked to carcinogenesis. The tumor specific 9-miRNA signature was also verified in the testing and entire set. In summary, based on UM data of TCGA, we identified and validated a 9-miRNA-based prognostic signature.

Upregulated expression of HOXC8 is associated with poor prognosis of cervical cancer

Homeobox C8 (HOXC8) is a transcription factor that has been reported to regulate numerous genes associated with tumor progression. However, its function in cervical cancer (CC) remains to be elucidated. In the present study, the expression level of HOXC8 was examined in CC tissues and cell lines using reverse transcription-quantitative polymerase chain reaction and western blot analysis. Additionally, CC cell lines were transfected with small interfering RNAs (siRNAs) to downregulate the expression of HOX8 and assess cell proliferation using Cell Counting Kit-8. The results demonstrated a significantly increased expression of HOXC8 in CC tissues and cell lines compared with non-tumor tissues, and a normal cervical cell line, respectively. Additionally, the downregulation of HOXC8, which was achieved by siRNA transfection, significantly inhibited the proliferation rate of CC cell lines. Kaplan-Meier curves demonstrated that the increased expression of HOXC8 was associated with poor prognosis of patients with CC. Additionally, univariate and multivariate analysis revealed that HOXC8 was a significant and independent predictor for overall survival of patients with CC. In conclusion, the results of the present study suggest that HOXC8 may be involved in the progression of CC and may serve as a therapeutic target for CC.