Expression and clinical study of Lin28A/B in head and neck squamous cell carcinoma / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE Through the research of analyzing the expression level of Lin28A/B proteins in tissues of head and neck squamous cell carcinoma and the expression of the downstream miRNA genes in order to provide a new clue for the diagnoses and treatment of the head and neck squamous cell carcinoma.METHODS A retrospective study was performed in 20 patients with head and neck squamous cell carcinoma and the clinical data were recorded.The expression level of Lin28A/B proteins were detected by immunohistochemistry in HNSCCs tissues and their matched normal tissues.tThe expression level of miRNA were analyzed in 6 HNSCC patients and other 6 patients with benign pathological changes,with the application of gene chips to detect the expression.Methods of Western Blot and RT-PCR were both utilized to detect expression levels of proteins and transcriptive levels of miRNAs correspondingly,in Scc23,Tca8113 and FADU cell lines.RESULTS Over-expression of Lin28A/B were found in head and neck squamous cell carcinoma tissues and the expression had a significant relation to advanced stage or lymph node metastasis.In addition,Lin28A was expressed in cytoplasm,while Lin28B was expressed in the nucleus.Correspondingly,in miRNA array,downregulated let-7a,let-7b,let-7g and let-7f-1 were detected in HNSCCs compared with the control group.In vitro study,the over-expression of Lin28A/B was found in Scc23 and Tca8113.The results of the CE and NE confirm that Lin28A was expressed in cytoplasm,while Lin28B was expressed in the nucleus and the results were consistent with that of Immunohistochemistry.On the contrary,RT-PCR showed that Let-7a transcription was relatively low in Scc23 and Tca8113 0.46±0.02 and 0.60±0.13.CONCLUSION As a RNA-binding protein,Lin28A/B selectively inhibit the biosynthesis of let-7 family.This study showed that the overexpression of Lin28A/B in head and neck squamous cell carcinoma tissues were related to the level of malignancy and the abnormal expression of let-7 family were also found.In contrast to the Lin28A,the Lin28B was expressed in the nucleus and this result provides some new idea for the further study of functional researches and expanding experiments in next step.