Resistance of ovarian
mucinous adenocarcinoma to standard
chemotherapy with
paclitaxel and
carboplatin is associated with poor prognosis, and an effective treatment is needed. The present study aimed to identify an effective
chemotherapy for ovarian
mucinous adenocarcinoma. Five human ovarian
mucinous adenocarcinoma cell lines (MN-1, OMC-1, RMUG-L, RMUG-S, TU-OM-1) were used in this study. Sensitivity of the cells to the
anticancer agents was determined by
3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and we assessed
drug sensitivity by calculating the assay area under the curve for each agent.
Protein expression was confirmed by Western blot analysis. We also examined the efficacy of
combination chemotherapy on survival in a xenograft model of nude mice. The IC(50) to
anticancer agents ranged widely. The assay area under the curve indicated that two of five cell lines (MN-1, TU-OM-1) were sensitive to
oxaliplatin,
5-fluorouracil and
etoposide, and only one (TU-OM-1) was sensitive to
7-ethyl-10-hydroxycamptothecin, which is an active metabolite of
camptothecin. All cell lines were resistant to
cisplatin and
paclitaxel. The combination of
oxaliplatin and
5-fluorouracil resulted in additive or synergistic effects on all cell lines. The combination of
oxaliplatin and
5-fluorouracil significantly prolonged survival in a ovarian
mucinous adenocarcinoma xenograft model of nude mice.
Protein expression levels of the excision repair cross-complementation group 1 were lower in
oxaliplatin sensitive cell lines. Exposure to
5-fluorouracil down-regulated cross-complementation group 1 expression in ovarian
mucinous adenocarcinoma cells. We conclude that
combination chemotherapy consisting of
oxaliplatin and
5-fluorouracil was an effective treatment for ovarian
mucinous adenocarcinoma and may be a pivotal candidate for a novel treatment strategy.