miR-454-3p prevents ox-LDL-induced apoptosis in HAECs by targeting TRPC3

Endothelial-cell (EC) apoptosis serves a vital role in the pathogenesis of atherosclerosis. Accumulating evidence has implicated microRNA (miRNA/miR) dysregulation in EC apoptosis. Although the role of miR-454-3p in carcinogenesis has been well documented, its role and underlying mechanism in EC apoptosis remain unclear. In the present study, the results revealed that miR-454-3p expression was substantially downregulated in human aortic endothelial cells (HAECs) following oxidized low-density lipoprotein (ox-LDL) treatment. miR-454-3p suppression significantly attenuated the viability of HAECs, while miR-454-3p overexpression repressed ox-LDL-induced HAEC apoptosis. Bioinformatics analysis and luciferase reporter assays revealed that transient receptor potential canonical 3 (TRPC3), a key regulator of atherosclerosis development, was the direct target of miR-454-3p. Furthermore, TRPC3 overexpression abolished the anti-apoptotic effect of miR-454-3p on HAECs. These results revealed a novel role of miR-454-3p in ox-LDL-induced apoptosis in HAECs.

EZH2-Inhibited MicroRNA-454-3p Promotes M2 Macrophage Polarization in Glioma

Glioma is a primary intracranial tumor with high incidence and mortality. The oncogenic role of EZH2 has been reported in glioma. EZH2 inhibited microRNA-454-3p (miR-454-3p) by binding to its promoter in chondrosarcoma cells. Therefore, our study aimed to identify whether EZH2 regulated M2 macrophage polarization in glioma via miR-454-3p. Clinical samples of different grades of glioma and glioma cells were collected and immunohistochemistry and RT-qPCR demonstrated that EZH2 was highly expressed in glioma tissues. Expression of EZH2 was positively correlated with the degree of M2 macrophage polarization in glioma tissues. EZH2 was silenced by lentivirus in glioma cells, which were subsequently co-cultured with macrophages to evaluate its effect on macrophage polarization. miR-454-3p, a down-regulated miR in glioma, was found to be increased after silencing of EZH2. Furthermore, MethPrimer analysis showed that EZH2 silencing inhibited the DNA methylation level of miR-454-3p. Additionally, MS-PCR, dual-luciferase reporter, RIP and RNA pull down assays revealed that miR-454-3p promoted PTEN expression by inhibiting m⁶A modification through binding to the enzyme YTHDF2. Either inhibition of miR-454-3p or PTEN resulted in promotion of M2 macrophage polarization. Collectively, histone methyltransferase EZH2 inhibited miR-454-3p through methylation modification and promoted m⁶A modification of PTEN to induce glioma M2 macrophage polarization.

Exosomes-Derived Long Non-Coding RNA HOTAIR Reduces Laryngeal Cancer Radiosensitivity by Regulating microRNA-454-3p/E2F2 Axis

Background

Studies have revealed exosomes are implicated in tumor microenvironment and tumorigenesis. Emerging evidence suggests long non-coding RNAs (lncRNAs) possess pivotal roles in laryngeal cancer progression. For this study, we aimed to find out the mechanism of exosomes and lncRNA HOTAIR in laryngeal cancer.

Methods

Laryngeal cancer cells-derived exosomes were initially extracted, separated and identified. Flow cytometry was applied to detect apoptosis to evaluate the effect of exosomes on cell radiosensitivity. Dual luciferase reporter gene assay, RNA pull-down and RNA immunoprecipitation assays were conducted to verify the interactions among HOTAIR, microRNA (miR)-454-3p and E2F2. The gain-and-loss functions of HOTAIR or miR-454-3p were carried out to explore their effects on TU212 and LLN cell viability, apoptosis and radiosensitivity. Levels of HOTAIR, miR-454-3p and E2F2 were detected after different treatments. An in vivo analysis was carried out in mice bearing laryngeal cancer xenografts.

Results

Laryngeal cancer-derived exosomes reduced laryngeal cancer cell radiosensitivity. HOTAIR expression was increased after cells were treated with exosome, and HOTAIR overexpression reduced laryngeal cancer cell radiosensitivity. Besides, HOTAIR worked as a competing endogenous RNA (ceRNA) of miR-454-3p to regulate E2F2 in laryngeal cancer cells. In vivo results were reproduced in in vivo studies, which demonstrated that HOTAIR knockdown reduced laryngeal cancer cell radiosensitivity by sponging miR-454-3p to silence E2F2.

Conclusion

Exosome-mediated HOTAIR acts as a ceRNA of miR-545-3p to regulate E2F2, thereby negatively regulating the radiosensitivity of laryngeal cancer cells. This study may offer novel insight into laryngeal cancer treatment.

miR-454-3p promotes of human glioma cell growth by targeting EGR3

Gliomas are the most common primary brain tumors in adults and are associated with high mortality rates. In the present study, the aim was to evaluate the role of miR-454-3p in the pathogenesis of human glioma and to explore the underlying mechanism. Reverse transcription-quantitative PCR was performed to compare the expression levels of miR-454-3p in glioma and adjacent normal tissue. The effects of miR-454-3p on cell proliferation was tested by combining MTT and colony formation assays. Dual-luciferase assay was used to identify the target gene of miR-454-3p. The results showed that miR-454-3p was upregulated in glioma tissues where it exerts a positively regulatory role on cell growth. Dual-luciferase assay confirmed Early Growth Response 3 (EGR3) to be a target for miR-454-3p. Overexpression of EGR3 in glioma cells was found to impair miR-454-3p mimic-induced cell proliferation. These results suggested that upregulated miR-454-3p served an important role in glioma tumorigenesis by targeting EGR3, which provided valuable insights into the underlying mechanism of the disease that may lead to possible novel therapeutic strategies.

MicroRNA-454-3p inhibits cervical cancer cell invasion and migration by targeting c-Met

Increasing evidence has demonstrated that microRNAs (miRNAs) have a crucial role in the initiation and progression of tumors. The present study aimed to investigate the expression and the role of miRNA-454-3p in human cervical cancer. Human cervical cancer cells were transfected with miRNA-454-3p mimics or negative control miRNA. MTT, Transwell and wound healing assays were performed to investigate the effects of miRNA-454-3p overexpression on cell proliferation, invasion and migration, respectively. The results indicated that miRNA-454-3p was down-regulated in human cervical cancer cell lines, while its ectopic overexpression significantly inhibited their proliferation, migration and invasion. Furthermore, a luciferase reporter assay confirmed that c-met was a novel target of miRNA-454-3p in HeLa cells. In conclusion, the results of the present study suggested that miRNA-454-3p exhibits significant tumor-suppressive effects in cervical cancer by targeting c-met, and may be a potential means of treating cervical cancer.