Promoter Methylation-Regulated miR-145-5p Inhibits Laryngeal Squamous Cell Carcinoma Progression by Targeting FSCN1

Abstract

Laryngeal squamous cell carcinoma (LSCC) is a common form of head and neck cancer with poor prognosis. However, the mechanism underlying the pathogenesis of LSCC remains unclear. Here, we demonstrated increased expression of fascin actin-bundling protein 1 ( FSCN1 ) and decreased expression of microRNA-145-5p (miR-145-5p) in a clinical cohort of LSCC. Luciferase assay revealed that miR-145-5p is a negative regulator of FSCN1 . Importantly, low miR-145-5p expression was correlated with TNM (tumor, node, metastasis) status and metastasis. Moreover, cases with low miR-145-5p/high FSCN1 expression showed poor prognosis, and these characteristics together served as independent prognostic indicators of survival. Gain- and loss-of-function studies showed that miR-145-5p overexpression or FSCN1 knockdown inhibited LSCC migration, invasion, and growth by suppressing the epithelial-mesenchymal transition along with inducing cell-cycle arrest and apoptosis. Additionally, hypermethylation of the miR-145-5p promoter suggested that repression of miR-145-5p arises through epigenetic inactivation. LSCC tumor growth in vivo could be inhibited by using miR-145-5p agomir or FSCN1 small interfering RNA (siRNA), which highlights the potential for clinical translation. Collectively, our findings indicate that miR-145-5p plays critical roles in inhibiting the progression of LSCC by suppressing FSCN1 . Both miR-145-5p and FSCN1 are important potential prognostic markers and therapeutic targets for LSCC.

Identification of miR‐145‐5p‐Centered Competing Endogenous RNA Network in Laryngeal Squamous Cell Carcinoma

“…Our previous study found that endogenous level of miR‐145‐5p was very low in LSCC cell lines TU‐177 and Hep2 . To investigate genes regulated by miR‐145‐5p in LSCC cells, we transfected LSCC cell line TU‐177 with miR‐145‐5p mimics.…”

“…To investigate genes regulated by miR‐145‐5p in LSCC cells, we transfected LSCC cell line TU‐177 with miR‐145‐5p mimics. qPCR results showed that miR‐145‐5p was overexpressed successfully ( Figure A), and its representative target FSCN1 was downregulated in miR‐145‐5p mimics transfected cells (Figure B). After microarray experiments and data preprocessing, 26 differentially expressed miRNAs including 14 up‐ and 12 down‐regulated ones were identified in cancer cells transfected with miR‐145‐5p mimics when compared to those transfected with control under the thresholds of fold change >2.0 and p value < 0.05.…”

“…Cells were harvested after 48 h transfection. Expression of miR‐145‐5p and its representative target FSCN1 was determined by qPCR.…”

“…Importantly, miR‐145 has also been reported to be lowly expressed in LSCC, and overexpression of which inhibits the proliferation and metastasis in LSCC cell line, Hep‐2, via inducing cell cycle arrest and apoptosis . Recently, we reported that the miR‐145‐5p plays a critical role in inhibiting LSCC progression via suppressing FSCN1 . However, its role in the transcriptional regulatory mechanisms of LSCC cells, especially in the regulatory network of lncRNA, circRNA, and mRNA remains unclear.…”

ESRRG promoter hypermethylation as a diagnostic and prognostic biomarker in laryngeal squamous cell carcinoma

“…ZNF667‐AS1 may be associated with the epithelial‐mesenchymal transition (EMT) process. Similarly, hypermethylation of the miR‐145‐5p promoter inhibits the expression of miR‐145‐5p which is a negative regulator of fascin actin‐bundling protein 1 ( FSCN1 ), this effect is associated with the migration, invasion, and growth of LSCC because EMT is suppressed, and cell‐cycle arrest and apoptosis are induced . Promoter methylation of both ZNF667‐AS1 and miR‐145‐5p is an important potential prognostic marker and therapeutic target for LSCC.…”