Differentially expressed genes associated with cis-diamminedichloroplatinum (II) resistance in head and neck cancer using differential display and cDNA microarray

Background. The mechanism by which cancer cells become resistant to cis-Diamminedichloroplatinum (II) (cDDP) is not completely understood. To investigate the molecular markers involved in the cDDP resistance, we compared the gene expression profiles between a head and neck squamous cell carcinoma (HNSCC) line sensitive to cDDP and its cDDP-resistant variant. Methods. Both a fluorescent differential display and a cDNA microarray analysis were applied to distinguish the gene profiles between KB, a human HNSCC line, and its cDDP-resistant variant (KB/cDDP). These results were confirmed by Northern blot analysis. Results. One up-regulated gene, glycoprotein hormone alpha-subunit, and two down-regulated genes coding membrane proteins, human folate receptor and tumor-associated antigen L6, were identified in KB/cDDP cells. Conclusions. Our findings suggest that development of the cDDP-resistant phenotype is accompanied by alternations of gene expression including a glycoprotein hormone and membrane proteins. These gene products could be new molecular markers for resistance to cDDP. (C) 2003 Wiley Periodicals, Inc.