Clinical significance of microRNA-449a in hepatocellular carcinoma with microarray data mining together with initial bioinformatics analysis

A comprehensive evaluation of skin aging-related circular RNA expression profiles

Background

Circular RNAs (circRNAs) have been shown to play important regulatory roles in a range of both pathological and physiological contexts, but their functions in the context of skin aging remain to be clarified. In the present study, we therefore, profiled circRNA expression profiles in four pairs of aged and non‐aged skin samples to identify identifying differentially expressed circRNAs that may offer clinical value as biomarkers of the skin aging process.

Methods

We utilized an RNA‐seq to profile the levels of circRNAs in eyelid tissue samples, with qRT‐PCR being used to confirm these RNA‐seq results, and with bioinformatics approaches being used to predict downstream target miRNAs for differentially expressed circRNAs.

Results

In total, we identified 571 circRNAs with 348 and 223 circRNAs being up and downregulated that were differentially expressed in aged skin samples compared to young skin samples. The top 10 upregulated circRNAs in aged skin sample were hsa_circ_0123543, hsa_circ_0057742, hsa_circ_0088179, hsa_circ_0132428, hsa_circ_0094423, hsa_circ_0008166, hsa_circ_0138184, hsa_circ_0135743, hsa_circ_0114119, and hsa_circ_0131421. The top 10 reduced circRNAs were hsa_circ_0101479, hsa_circ_0003650, hsa_circ_0004249, hsa_circ_0030345, hsa_circ_0047367, hsa_circ_0055629, hsa_circ_0062955, hsa_circ_0005305, hsa_circ_0001627, and hsa_circ_0008531. Functional enrichment analyses revealed the potential functionality of these differentially expressed circRNAs. The top 3 enriched gene ontology (GO) terms of the host genes of differentially expressed circRNAs are regulation of GTPase activity, positive regulation of GTPase activity and autophagy. The top 3 enriched KEGG pathway ID are Lysine degradation, Fatty acid degradation and Inositol phosphate metabolism. The top 3 enriched reactome pathway ID are RAB GEFs exchange GTP for GDP on RABs, Regulation of TP53 Degradation and Regulation of TP53 Expression and Degradation. Six circRNAs were selected for qRT‐PCR verification, of which 5 verification results were consistent with the sequencing results. Moreover, targeted miRNAs, such as hsa‐miR‐588, hsa‐miR‐612, hsa‐miR‐4487, hsa‐miR‐149‐5p, hsa‐miR‐494‐5p were predicted for circRna‐miRna interaction networks.

Conclusion

Overall, these results offer new insights into circRNA expression profiles, potentially highlighting future avenues for research regarding the roles of these circRNAs in the context of skin aging.

Effect of miR‑449a‑mediated Notch signaling pathway on the proliferation, apoptosis and invasion of papillary thyroid carcinoma cells

The present study aimed to investigate the effect of miR‑449a‑mediated Notch signaling pathway on the proliferation, apoptosis and invasion of papillary thyroid carcinoma cells. Human papillary thyroid carcinoma cell line TPC‑1 was selected, and cells were grouped and transfected: Control group (without any treatment), negative control (NC) group (transfection with NC plasmid), miR‑449a mimic group (transfection with miR‑449a mimic), miR‑449a inhibitor group (transfection with miR‑449a inhibitor), DAPT group (addition of γ‑secretase inhibitor DAPT to inhibit the Notch signaling pathway), and miR‑449a inhibitor + DAPT group (transfection with miR‑449a inhibitor and addition of DAPT). The target relationship between miR‑449a and Notch1 was detected by dual‑luciferase reporter assay. qRT‑PCR and western blotting were used to assess the expression of miR‑449a, Notch1 and Jagged1 in cells. Cell proliferation was detected using EdU; the cell cycle and apoptosis were detected by flow cytometry; cell invasion ability was detected by Transwell assay. PCNA, MMP‑2, MMP‑9, Bcl‑2 and Bax mRNA and protein expression were assessed by qRT‑PCR and western blotting. The results revealed that miR‑449a negatively regulated Notch1. Compared with the control group, there was significantly increased miR‑449a expression in the miR‑449a mimic group, and there was significantly decreased expression of Notch1, Jagged1, PCNA, MMP‑2, MMP‑9 and Bcl‑2, increased Bax, reduced cell proliferation, increased G1‑phase cell fraction, decreased S‑phase cell fraction, an increased apoptosis rate, and decreased invasion ability in the miR‑449a mimic group and DAPT group (all P<0.05). However, the results in the miR‑449a inhibitor group were the opposite of those in miR‑449a mimic group (all P<0.05). There was no significant difference in cell proliferation, apoptosis and invasion in the NC group and miR‑449a inhibitor + DAPT group compared to the control group (all P>0.05). miR‑449a overexpression can inhibit Notch signaling pathway, thereby inhibiting the proliferation and invasion of papillary thyroid carcinoma cells and promoting cell apoptosis.