BACKGROUND ; OBJECTIVE: Ovarian cancer is the leading cause of death among the gynecological malignancy mainly due to lacking of effective early diagnostic methods. To identify novel candidate genes and further explore their clinical significance of epithelial ovarian tumors, we developed a new method in our laboratory by combining cDNA microarray with RNA in situ hybridization in frozen tissue microarray. METHODS: cDNA microarrays were used to seek differentially expressed genes among 3 subtypes of ovarian tumors (serous borderline ovarian tumors, serous ovarian cancers, and endometrioid ovarian carcinomas). RNA in situ hybridization in frozen tissue microarray was used to further confirm the findings from cDNA microarrays. RESULTS: In the study of cDNA microarray, 40 genes and ESTs showed significant differential expression between low and high-malignancy, as well as serous and endometrioid carcinomas. EPHB6, PTPRF, GFER, ERG25, PLRP1, FLJ22060, and WISP2 were further validated by RNA in situ hybridization in tissue microarray. CONCLUSIONS: cDNA microarray combined with RNA in situ hybridization in frozen tissue microarray is an ideal choice for identifying novel oncogenes. EPHB6, PTPRF, GFER, ERG25, PLRP1, FLJ22060, and WISP2 might become the new candidate oncogenes for epithelial ovarian cancer.
