The Mechanism Research On Regulation Disorder Between Hsa-miR-145-5p And Its Target Gene FSCN1and Clinical Significance In Laryngeal Squamous Cell Carcinoma

Objective:MicroRNAs (miRNAs) are endogenous short non-coding RNA molecules thatregulate gene expression by repressing translation or cleaving RNA transcripts in asequence-specific manner. We aim to get the expression profiles of microRNAs inlaryngeal squamous cell carcinoma (LSCC). We investigated the association ofmiR-145-5p and its target gene FSCN1expression with clinicopathologic factors andtheir prognostic value in LSCC. Finaly, we identify the main function of miR-145-5pand FSCN1in Hep-2and TU-177.Methods:We used microRNA chip to identify the expression profiles in LSCC. Thebioinformatics was used in prediction of regulation between miR-145-5p and FSCN1which was validated by fluorescent report vector. Quantitative RT-PCR and westernblot analyses were used to examine mRNA and protein levels in10fresh LSCCspecimens and10corresponding adjacent normal margin (ANM) tissues frompatients undergoing surgery in2012. We used immunohistochemistry toretrospectively study188paraffin blocks of LSCC samples from patients who hadundergone surgery between2000and2006and had not received special treatmentbefore the diagnosis. Univariate analysis of patient survival involved the Kaplan–Meier method. Multivariate analyses involved the Cox proportional hazards model.The gene transfection and siRNA technology was used in order to explore theirfunctions on the malignant phenotype of laryngeal squamous carcinoma cells in vitro. The biological information technology was used in forecasting methylation sites ofHsa-miR-145-5p which was validated by quantitative methylation sequencing.Finally, we detected the changes of key molecules of epithelial-mesenchymaltransition (EMT) after Hsa-miR-145-5p-FSCN1axis was rescued in vitro.Results:Hsa-miR-145-5p, one of the multifarious microRNA, was significantlydown-regulated in laryngeal squamous cell carcinoma. FSCN1was the direct targetgene of miR-145-5p. It could inhibit the proliferation, clone, migration, invasion oflaryngeal squamous carcinoma cell which were arrested in G0/G1phase, andpromoted into apoptosis by recovery of miR-145-5p or siRNA of FSCN1.Low expression of miR-145-5p and high expression pattern of FSCN1weresignificantly observed in laryngeal squamous cell carcinoma. The low expression ofmiR-145-5p was positively correlated with poor tumor differentiation, cervical lymphnode metastasis (N+), and advanced clinical stage (III+IV), but not sex, denger ormetastasis. In addition, a high expression of FSCN1was associated with advancedtumor stage (T3+T4). The expression of fascin-1was higher in smokers thannon-smokers. A high expression of FSCN1or low expression of miR-145-5p wasassociated with poor prognosis. Low expression of miR-145-5p with high expressionof FSCN1is an independent risk factor for LSCC patients with poor prognosis.MiR-145-5p promoter hypermethylation caused the imbalance ofhsa-miR-145-5p-FSCN1axis, resulting in regulation disorder of FSCN1, whichplayed an important biological effect in tumor cell malignant mesenchymal transition(EMT).Conclusions:The regulation disorder between miR-145-5p and FSCN1is important molecularevent in the process of malignant progression and metastasis in laryngeal squamous cell carcinoma. miR-145-5p is an actor as tumor suppressor gene but proto-oncogeneof FSCN1which might be prognostic of poor outcome with LSCC after surgery. Ourstudy may lead to establishing new molecular therapeutic targets and/or prognosticbiomarkers in LSCC.