We established 2 novel human cell lines (GCCOT-1, GCCRK) from glassy cell carcinoma. Both cell lines showed dual tendencies of glandular and squamous differentiation, and thus possess the characteristics resembling reserve cells, the putative origin of most carcinomas arising from the uterine cervix. HPV type 18 DNA including E6-E7, which is commonly found in cell types other than squamous cell carcinoma of uterine cervix, was detected in both cell lines. We analyzed gene copy number alterations of the 2 cell lines using conventional comparative genomic hybridization (CGH) coupled with array-based CGH. Among the putative oncogenes demonstrating copy number gain in both cell lines, FGR(SRC2) at 1p36.2-1 and LAMC2 at 1q25-31 have not been reported to show amplification in previous analyses of conventional cervical cell lines. These oncogenes are thus speculated to be directly associated with oncogenesis of glassy cell carcinoma. On the other hand, among the putative suppressor genes demonstrating copy number loss in both cell lines, the 9q region, ATM at 11q22.3, and CYLD at 16q12-13 have not been reported to show loss in conventional cervical cancer cell lines. These sites are speculated to be important as tumor suppressors directly associated with oncogenesis of glassy cell carcinoma. This study suggests for the first time that together with the presence of HPV type 18, alterations at the above sites are closely associated with oncogenesis of glassy cell carcinoma, a special type of carcinoma in the uterine cervix.