OBJECTIVETo investigate the association of mutations and expression of MUS81 gene with the tumorigenesis and progression of laryngeal squamous cell carcinoma (LSCC).

METHODSPCR-SSCP and DNA sequencing were carried out to examine mutations at exons 9 and 10 of MUS81 gene in 42 LSCC samples, with paired adjacent normal laryngeal tissues (PANLs) as control. Semi-quantitative RT-PCR and Western blot were used to detect the expression of MUS81 gene in the specimens.

RESULTSNo mutation was detected in the control group. Among the 42 LSCC specimens, nineteen (45.2%) were found to harbor mutations, including 11(26.2%) occurring within exon 9, and 8 (19%) within exon 10. Seventeen (40.48%) samples showed lower mRNA level of the MUS81 gene (P<0.01), and same proportion of samples had lower protein level (P<0.01), suggesting that MUS81 gene was similarly down-regulated at both mRNA and protein levels in the LSCC samples. Furthermore, mutations of MUS81 gene did not significantly correlate with TNM stages, age and lymphoid node metastasis (P>0.05). Nor did the expression of MUS81 gene with the TNM stages, age and lymphoid node metastasis in LSCC (P>0.05).

CONCLUSIONMutations and abnormal expression of MUS81 gene in the LSCC tissues were observed, which suggested that abnormalities of MUS81 gene may play an important role in the tumorigenesis of LSCC.