Related Experiment Video
Updated: Aug 13, 2026
Enrichment for Chemoresistant Ovarian Cancer Stem Cells from Human Cell Lines
Published on: September 10, 2014
Mechanisms determining sensitivity to cisplatin in three mutant Chinese hamster ovary cell lines
1Department of Medical Oncology, Westmead Hospital, Westmead, Sydney, NSW, Australia.
Abstract:
To gain insight into factors determining the response of tumours to cisplatin, we studied pathways involved in resistance to cisplatin: drug uptake, cytoplasmic detoxification and DNA repair, in three cisplatin-sensitive Chinese hamster ovary (CHO)2 mutant cell lines. The mutant lines, CHO-MMC6, CHO-MMC1, CHO-MMS2, displayed inherent sensitivity to cisplatin (2.2, 4.1 and 10.6-fold, respectively) compared to the CHO-K1 line from which they were derived. CHO-MMS2 was the only mutant to show sensitivity to UV and this was slight (< 2-fold). None of the mutants displayed increased sensitivity to X-irradiation. The CHO-MMS2 cell line appeared to have multiple mechanisms involved in its sensitivity to cisplatin, including increased drug accumulation, decreased levels of glutathione and a decreased capacity for DNA repair. The CHO-MMC1 mutant demonstrated reduced ability for DNA repair in a host cell reactivation assay, but no difference in drug accumulation or glutathione levels compared to the parent. The CHO-MMC6 cell line was not defective in any of the mechanisms studied. These three mutant cell lines demonstrate that similar mechanisms may account for inherent sensitivity or resistance to cisplatin, and suggest that multiple mechanisms may determine the sensitivity of human tumours to cisplatin.
Insights
Investigating cisplatin resistance mechanisms in Chinese hamster ovary (CHO) cells revealed that increased drug uptake, decreased glutathione, and impaired DNA repair contribute to sensitivity. Multiple pathways likely determine tumor response to cisplatin.
Area of Science:
- Cell Biology
- Molecular Biology
- Cancer Research
Background:
- Cisplatin is a crucial chemotherapy drug.
- Understanding cisplatin resistance is vital for effective cancer treatment.
- Chinese hamster ovary (CHO) cell lines offer a model for studying drug resistance mechanisms.
Purpose of the Study:
- To investigate the mechanisms of cisplatin resistance in CHO cell lines.
- To identify key pathways involved in cellular response to cisplatin, including drug uptake, detoxification, and DNA repair.
- To correlate specific cellular mechanisms with varying degrees of cisplatin sensitivity.
Main Methods:
- Utilized three cisplatin-sensitive Chinese hamster ovary (CHO) mutant cell lines (CHO-MMC6, CHO-MMC1, CHO-MMS2).
- Assessed drug accumulation, cytoplasmic detoxification (glutathione levels), and DNA repair capacity.
- Employed host cell reactivation assays to evaluate DNA repair efficiency.
- Compared mutant cell lines to the parental CHO-K1 line.
Main Results:
- CHO-MMS2 cells exhibited multiple resistance mechanisms: increased cisplatin accumulation, decreased glutathione, and reduced DNA repair capacity.
- CHO-MMC1 cells showed impaired DNA repair but normal drug accumulation and glutathione levels.
- CHO-MMC6 cells did not display defects in the studied resistance mechanisms.
- Mutant sensitivity to UV and X-irradiation varied, with only CHO-MMS2 showing slight UV sensitivity.
Conclusions:
- Inherent sensitivity or resistance to cisplatin can be mediated by similar cellular mechanisms.
- Multiple interacting pathways likely govern the sensitivity of human tumors to cisplatin.
- These findings provide insights into predicting and overcoming cisplatin resistance in cancer therapy.
