Isolation and Identification of cDNA Sequences Differentially Expressed in Laryngeal Carcinoma

The isolation of the genes related to laryngeal carcinoma(LC) is necessary for revealing mechanisms of carcinogenesis and genetic predisposition to LC. The mRNA differential display method was used to compare and analyze mRNAs prepared from two adult laryngeal carcinoma tissues and paired tumor-adjacent normal tissues. A total of twenty-two differential display experiments was performed and thirty-five cDNA fragments differentially expressed in normal or malignant laryngeal epithelial tissues were identified. Differential expression of six of these thirty-five cDNA fragmens was confirmed by reverse northern dot blot. Subsequent cloning of six differentially expressed cDNA fragments and sequencing and BLASTn analysis resulted in the identification of twelve distinct cDNA sequences. Four of these were shown to be novel gene sequences that have not been reported. Eight of the remaining cDNA sequences showed sequence homology to those previously reported. The differential expression of these twelve cDNA sequences in the carcinoma or normal tissue of the larynx were confirmed by fixing the twelve cDNA sequences on the membrane, followed by the hybridization with the total cDNA probes from laryngeal carcinoma or normal tumor-adjacent tissues and by differential RT-PCR. These results suggest that these cDNA sequences might be involved in carcinogenesis of laryngeal carcinoma.