Abstract:

Abstract：Objective To screen the target genes that contribute to cisplatin resistance in ovarian cancer treatment.
Methods Gene expression and methylation profiles of ovarian cancer cells that were sensitive or resistant to cisplatin with
accession number GSE15709 were downloaded from GEO database. Differential expressed and methylated genes were identi⁃
fied through associating packages in R. DAVID database to screen the enriched GO terms and pathways of the different ex⁃
pressed genes between A2780 and A2780/DDP. Gene Set Enrichment Analysis (GSEA) of different gene was performed
against DAVID database. Genes that exhibited difference in both expression and methylation profiles between the two types
of ovarian cancer cells as well as genes that present contradictory profile between expression and methylation were verified
via qRT-PCR. Results We found 416 different expressed genes and 281 methylated genes between the two types of ovari⁃
an cancer cells respectively. These differential genes were rich in pathways of cell cycle, DNA replication, nucleus division，
p53 signaling , and negative regulation of protein modification process etc. Four genes demonstrated contradictory profile be⁃
tween expression and methylation in the two types of ovarian cancer cells and were verified by qRT- PCR. Conclusion
Combination of bioinformatics and molecular biology is useful in the identification of target genes that contribute to resis⁃
tance of cisplatin in ovarian cancer treatment and further reveal molecular mechanism behind it.

Key words: cisplatin, ovarian neoplasms, computational biology, reverse transcriptase polymerase chain reaction, qRTPCR, A2780, A2780/DDP