Look this article at

http://www.pnas.org/content/89/7/3070.full.pdf

and this site

http://www.nature.com/nature/journal/v483/n7391/full/nature11005.html

The IC50 value of cisplatin differs among cell lines as different cell lines have different cytotoxic susceptibilities to the drug. There are plenty of reports on the IC50 values of cisplatin on a variety of cancer cell lines. Also, there are reports as the how cells grown as 3D aggregates are differently susceptible to drug-induced cytotoxicity compared to their 2D monolayers.

We tested more times the cytotoxic and antiproliferative effect of cisplatin against A2780 and the IC50 values were approximately 1 uM (based on MTT assays).

See this article: https://www.ncbi.nlm.nih.gov/pubmed/26686898