Inhibitory roles of miR‑9 on papillary thyroid cancer through targeting BRAF

Abstract

MicroRNA‑9 (miR‑9) is reported to be underexpressed in papillary thyroid carcinoma (PTC) tissues; however, the molecular mechanisms underlying the implication of miR‑9 in PTC have yet to be elucidated. The present study aimed to explore the potential roles of miR‑9 in PTC. PTC tissue samples and paired non‑cancerous adjacent tissues were collected from 60 patients with PTC. The human TPC‑1 thyroid gland papillary carcinoma cell line was used to investigate the molecular mechanisms underlying the roles of miR‑9 in PTC. The levels of miR‑9 and its downstream target gene BRAF were detected through reverse transcription‑quantitative polymerase chain reaction. MTT assay and flow cytometry were performed to evaluate cell viability and apoptosis, respectively. A mouse xenograft tumor model was established to observe the effects of miR‑9 on thyroid gland tumorigenesis in vivo. The present study revealed that the expression of miR‑9 was significantly reduced in PTC tissues compared with paired normal tissues. In addition, miR‑9 upregulation suppressed the expression of BRAF in TPC‑1 cells in vitro. Luciferase reporter assay demonstrated that BRAF may be a direct target gene of miR‑9 in TPC‑1 cells. In addition, following transfection with miR‑9 mimics, the viability of TPC‑1 cells was suppressed and their apoptosis was enhanced; conversely, transfection with miR‑9 inhibitor exerted the opposite effects in vitro. miR‑9 overexpression or downregulation also affected in vivo PTC tumorigenesis in athymic mice. The present findings suggested that miR‑9 may suppress the viability of PTC cells and inhibit tumor growth through directly targeting the expression of BRAF in PTC.

The miR-582/CD1B Axis Is Involved in Regulation of Dendritic Cells and Is Associated with Clinical Outcomes in Advanced Lung Adenocarcinoma

“…Moreover, miR-196b promotes cell migration and invasion by targeting FOXP2 in hepatocellular carcinoma and regulates self-renewal, differentiation, and transformation by targeting HOXC8 in breast cancer stem cells [37,38]. miR-9 has an inhibitory role in papillary thyroid cancer by targeting BRAF and reduces metastatic behavior in triple-negative breast cancer by targeting NOTCH1 [39,40]. However, the roles of these miRNAs in lung cancer and their potential therapeutic applications have not been evaluated.…”

BRAFV600E mutation, BRAF-activated long non-coding RNA and miR-9 expression in papillary thyroid carcinoma, and their association with clinicopathological features

“…Consistent with our finding, Sondermann A et al [29] observed the significantly downregulated expression of miR-9 in patients with recurrent Table 3 Relationships between clinicopathological characteristics of PTC patients and BRAF V600E mutation status and BANCR and miR-9 expression in carcinoma tissue (n = 51) PTC, which can be used as a prognostic indicator of PTC. Gu Y et al [30] found that miR-9 may inhibit the activity of PTC cells and tumor growth by directly targeting the expression of BRAF in PTC. In the present study, patients with BRAF V600E mutation have a higher rate of BANCR overexpression and tended to have a lower rate of miR-9 overexpression (P = 0.057), and there is a negative association were found between BANCR and miR-9 expression levels.…”

Targeting the effect of sofosbuvir on selective oncogenes expression level of hepatocellular carcinoma Ras/Raf/MEK/ERK pathway in Huh7 cell line

“…Moreover, the GC contents of all primers were between 50-60 percent, melting temperature was almost 62 °C and there were no more than four repeats of bases. Primers were not self-complementary, thus the chance of primer dimerization during reaction were zero ( Yasumura et al, 2004 , Charette et al, 2010 , Xu et al, 2010 Yang et al, 2015 , Singh et al, 2017 , Xu et al, 2017a , Xu et al, 2017b , Gu et al, 2018 , Liu et al, 2018 , Kalimutho et al, 2019 ). Table 1 .…”