The Expression Of Id-1 And Its Significance In Laryngealcarcinoma

Objective To investigate the gene expression of Id-1 in laryngeal carcinoma and analyze the relationship between expression of Id-1 and clinical factors. Inhibitor of differentiation/DNA binding (Id) proteins are transcription factors, involved in cell cycle regulation and neoangiogenesis. Id-1 (Inhibitor of differentiation/DNA binding) is a member of the helix-loop-helix protein family expressed in actively proliferating cells. It regulates gene transcription by heterodimerization with the basic helix-loop-helix transcription factors and therefore inhibits them from DNA binding and transactivation of their target genes. Early studies showed that Id-1 functions mainly as a regulator in cellular differentiation of the muscle cells, But it has not reported weather it can be found in laryngeal carcinoma, How can Id-1 protein play a role in the process of laryngeal carcinoma.Method (1) The expression of Id-1 mRNA and its proteins were examined by RT-PCR and Western blot assay. 30 fresh surgical laryngeal carcinoma and adjacent normal tissue samples (3.5 cm from the margin of the tumor) were obtained from a total of 30 patients with laryngea carcinoma who under went Partial laryngectomy and total laryngectomy between October 2007 and April 2008 in the Department of Otolaryngology and Head-Neck surgery Xijing Hospital and Tangdu Hospital. Extraction of total RNA, Reprimers were designed, Using the PCR Reverse transcription polymerase chain reaction. (2) By Western blot assay detected the recombinant proteins using a mouse monoclonal antibody of the Id-1 as primary antibody. Goat anti-mouse IgG was applied as a secondary antibody. (3) Input all the result in computer use computer to analyze the optical density value of the Id-1 protein by SPSS 10.0 software. We analyze the different expression of Id-1 protein between laryngeal carcinoma tissues and normal laryngeal tissues, we also analyze the different expression of Id-1 protein between laryngeal carcinoma in different stage.Result (1) we can see bright belts in electrophoresis bath which contain the product of RT-PCR of laryngeal carcinoma tissues, that means the expression of Id-1 gene in laryngeal carcinoma tissues was significantly high. No bright belts in electrophoresis bath can be seen which contain the product of RT-PCR of normal laryngeal tissues, that means no Id-1 gene expression in normal laryngeal tissues .But this gene is expressed in Hep2 laryngeal carcinoma cell line. (2) From Western blot and Immunohistochemistry. The expression of Id-1 protein in laryngeal carcinoma tissues and Hep2 laryngeal carcinoma cell line is significantly high, and in normal laryngeal tissues, the protein is not expressed respectively (P<0.05). (3) In laryngeal carcinoma, the expression of Id-1 protein was significantly related to pathological grade and clinical stage.Conclusion The high level of Id-1 expression may contribute to the carcinogene -sis and development of laryngeal carcinoma. respectively (P<0.05). So it may be an important index for judging the differentiation, infiltration, metastasis and staging of laryngeal carcinoma.