miR‑497 inhibits the proliferation and migration of A549 non‑small‑cell lung cancer cells by targeting FGFR1

miR-497 inhibits proliferation and invasion in triple-negative breast cancer cells via YAP1

MicroRNA (miR)-497 has been reported as a tumor suppressor in various cancer types. Nonetheless, the regulation of triple-negative breast cancer (TNBC) by miR-497 remains poorly understood. The present study aimed to investigate the potential function and mechanism of miR-497 in TNBC. A total of 36 TNBC and matched non-cancerous tissue samples were collected for analysis. Reverse transcription-quantitative PCR was performed to detect the miR-497 levels in TNBC tissue. The association between miR-497 expression, clinical characteristics and survival was then analyzed. To investigate the role of miR-497 in TNBC, MTT, colony formation, Transwell invasion, cell cycle and cell apoptosis assays were conducted following transfection of miR-497 mimics into the MDA-MB-231 and MDA-MB-468 cell lines. Luciferase reporter assays and western blot analysis were used to confirm the regulation of a putative target of miR-497. The results indicated that the expression of miR-497 was downregulated in the TNBC specimens. Further analysis demonstrated that the expression of miR-497 was downregulated in patients with advanced TNBC stages and that low miR-497 was associated with poor prognosis in patients with TNBC. Transfection of miR-497 mimics inhibited TNBC cell proliferation and increased cell apoptosis in MDA-MB-231 and MDA-MB-468 cells. Moreover, cell migration was inhibited following overexpression of miR-497, which also led to the arrest of the breast cancer cells in the G₀/G₁ phase of the cell cycle. Yes-associated protein 1 (YAP1), a critical molecule in the Hippo pathway, was identified as a target of miR-497. Notably, the protein and mRNA expression levels of YAP1 in MDA-MB-231 and MDA-MB-468 cells were downregulated following overexpression of miR-497. Overall, the findings of the present study indicated that miR-497 inhibited TNBC cell proliferation and migration and induced cell apoptosis by negatively regulating YAP1 expression. Thus, targeting miR-497 may represent a potential strategy for the treatment of TNBC.

Effectiveness of porous silicon nanoparticle treatment at inhibiting the migration of a heterogeneous glioma cell population

BACKGROUND

Approximately 80% of brain tumours are gliomas. Despite treatment, patient mortality remains high due to local metastasis and relapse. It has been shown that transferrin-functionalised porous silicon nanoparticles (Tf@pSiNPs) can inhibit the migration of U87 glioma cells. However, the underlying mechanisms and the effect of glioma cell heterogeneity, which is a hallmark of the disease, on the efficacy of Tf@pSiNPs remains to be addressed.

RESULTS

Here, we observed that Tf@pSiNPs inhibited heterogeneous patient-derived glioma cells' (WK1) migration across small perforations (3 μm) by approximately 30%. A phenotypical characterisation of the migrated subpopulations revealed that the majority of them were nestin and fibroblast growth factor receptor 1 positive, an indication of their cancer stem cell origin. The treatment did not inhibit cell migration across large perforations (8 μm), nor cytoskeleton formation. This is in agreement with our previous observations that cellular-volume regulation is a mediator of Tf@pSiNPs' cell migration inhibition. Since aquaporin 9 (AQP9) is closely linked to cellular-volume regulation, and is highly expressed in glioma, the effect of AQP9 expression on WK1 migration was investigated. We showed that WK1 migration is correlated to the differential expression patterns of AQP9. However, AQP9-silencing did not affect WK1 cell migration across perforations, nor the efficacy of cell migration inhibition mediated by Tf@pSiNPs, suggesting that AQP9 is not a mediator of the inhibition.

CONCLUSION

This in vitro investigation highlights the unique therapeutic potentials of Tf@pSiNPs against glioma cell migration and indicates further optimisations that are required to maximise its therapeutic efficacies.

MicroRNA-497-5p stimulates osteoblast differentiation through HMGA2-mediated JNK signaling pathway

Background

Osteoporosis (OP) has the characteristics of the decline in bone mineral density and worsening of bone quality, contributing to a higher risk of fractures. Some microRNAs (miRNAs) have been validated as possible mediators of osteoblast differentiation. We herein aimed to clarify whether miR-497-5p regulates the differentiation of osteoblasts in MC3T3-E1 cells.

Methods

The expression of miR-497-5p in OP patients and controls was measured by RT-qPCR, and its expression changes during osteoblast differentiation were determined as well. The effects of miR-497-5p on the differentiation of MC3T3-E1 cells were studied using MTT, ALR staining, and ARS staining. The target gene of miR-497-5p was predicted by TargetScan, and the effects of its target gene on differentiation and the pathway involved were investigated.

Results

miR-497-5p expressed poorly in OP patients, and its expression was upregulated during MC3T3-E1 cell differentiation. Overexpression of miR-497-5p promoted mineralized nodule formation and the expression of RUNX2 and OCN. miR-497-5p targeted high mobility group AT-Hook 2 (HMGA2), while the upregulation of HMGA2 inhibited osteogenesis induced by miR-497-5p mimic. miR-497-5p significantly impaired the c-Jun NH2-terminal kinase (JNK) pathway, whereas HMGA2 activated this pathway. Activation of the JNK pathway inhibited the stimulative role of miR-497-5p mimic in osteogenesis.

Conclusions

miR-497-5p inhibits the development of OP by promoting osteogenesis via targeting HMGA2.

Hsa_circ_0043265 Suppresses Proliferation, Metastasis, EMT and Promotes Apoptosis in Non-Small Cell Lung Cancer Through miR-25-3p/FOXP2 Pathway

Purpose

Non-small cell lung cancer (NSCLC) is the largest type of lung cancer (LC) with a higher mortality rate. Circular RNAs (circRNAs) have been shown to play an important role in cancer progression. Therefore, this study was to explore the function of hsa_circ_0043265 in NSCLC.

Methods

The expression levels of hsa_circ_0043265, microRNA-25-3p (miR-25-3p) and forkhead box P2 (FOXP2) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Ribonuclease R (RNase R) and Actinomycin D (ActD) were used to verify the authenticity and stability of hsa_circ_0043265. Cell counting kit-8 (CCK-8), flow cytometry and transwell assays were used to evaluate the abilities of proliferation, apoptosis, migration and invasion of NSCLC cells. Also, Western blot (WB) analysis was performed to assess the levels of apoptosis, epithelial–mesenchymal transition (EMT) and proliferation-related proteins and FOXP2 protein. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were used to verify the interaction between miR-25-3p and hsa_circ_0043265 or FOXP2. Besides, mice xenograft models were constructed to confirm the effect of hsa_circ_0043265 on NSCLC tumor growth in vivo.

Results

Hsa_circ_0043265 was lowly expressed in NSCLC tissues and cells, and its overexpression inhibited the proliferation, migration, invasion and EMT process, while improved the apoptosis of NSCLC cells. MiR-25-3p could be sponged by hsa_circ_0043265, and its overexpression could invert the suppression effect of overexpressed-hsa_circ_0043265 on NSCLC progression. Moreover, FOXP2 was a target of miR-25-3p, and its silencing also could reverse the inhibition effect of overexpressed-hsa_circ_0043265 on NSCLC progression. In addition, hsa_circ_0043265 overexpression reduced the tumor growth of NSCLC in vivo.

Conclusion

Hsa_circ_0043265 could sponge miR-25-3p to improve FOXP2 expression, thereby inhibiting NSCLC progression. This study showed that hsa_circ_0043265 could be a potential biomarker for early diagnosis of NSCLC.