Different cDNA microarray patterns of gene expression reflecting changes during metastatic progression in adenoid cystic carcinoma.

BACKGROUND: The metastatic ability of tumor cells is determined by level of expression of specific genes that may be identified with the aid of cDNA microarray containing thousands of genes and can be used to establish the expression profile of disease related genes in complex biological system. MATERIALS AND METHODS: Salivary adenoid cystic carcinoma cell line and its high metastases adenoid cystic carcinoma clone were used as model systems to reveal the gene expression alteration related to metastasis mechanism by cDNA microarray analysis. The correlation of metastatic phenotypic changes and expression levels of 4 selected genes (encoding CD98, L6, RPL29, and TSH) were further validated by using RT-PCR analysis of human tumor specimens from primary adenoid cystic carcinoma and corresponding metastasis lymph nodes. RESULTS: Of the 7,675 clones of known genes and expressed sequence tags (ESTs) that were analyzed, 30 showed significantly different (minimum 3 fold) expression levels in two cell lines. Out of 30 genes found differentially expressed, 18 were up regulated (with ratio more than 3) and 12 down regulated (with ratio less than 1/3). CONCLUSION: Some of these genes are known to be involved in human tumor antigen, immune surveillance, adhesion, cell signaling pathway and growth control. It is suggested that the microarray in combination with a relevant analysis facilitates rapid and simultaneous identification of multiple genes of interests and in this study it provided a profound clue to screen candidate targets for early diagnosis and intervention.