In vitro activity: Cisplatin, an inorganic platinum complex, is a chemotherapeutic agent and a potent inducer of growth arrest and apoptosis in a variety of cell types. It is used for the treatment a number of cancers including testicular cancer, ovarian cancer, cervical cancer, breast cancer, bladder cancer, head and neck cancer, esophageal cancer, lung cancer, mesothelioma, brain tumors and neuroblastoma. Upon IV (intravenous) administration, Cisplatin forms highly reactive, charged, platinum complexes which bind to nucleophilic groups such as GC-rich sites in DNA, inducing intrastrand and interstrand DNA cross-links, as well as DNA-protein cross-links. This inhibits DNA synthesis and results in apoptosis and cell growth inhibition. Cisplatin induces cytotoxic by interaction with DNA to form DNA adducts which activate several signal transduction pathways, including Erk, p53, p73, and MAPK, which culminates in the activation of apoptosis. Cisplatin (30 mM) treated for 6 h induces an apparent activation of Erk in HeLa cells, which is sustained over the following 14 h period. Cisplatin also shows an effective antineoplastic activity by inducing tumor cells death. Cisplatin displays ability to cause renal proximal tubular cell (RPTC) apoptosis, causing cell shrinkage, a 50-fold increase in caspase 3 activity, a 4-fold increase in phosphatidylserine externalization, and 5- and 15-fold increases in chromatin condensation and DNA hypoploidy, respectively. Cisplatin (800 μM) causes typical features of necrosis of RPTC after treatment for 4 hr.

Cell Assay: L1210/0 cells are maintained in an exponential suspension culture at 37 ℃ in a humidified atmosphere of 5% CO2 in McCoy's medium 5a (modified), supplemented with 15% calfserum, and Fungizone. L1210/0 cells are incubated in Cisplatin (7 μg/mL) for 2 hr at 37 ℃. To measure growth inhibition, the cells are centrifuged, washed once, resuspended in fresh medium at 30 × 103 to 50 × 103 cells/mL, and incubated for 3 days. Cell numbers are determined on a Coulter Counter. An aliquot of cells is diluted with an equal volume of 0.4% trypan blue. Viability is recorded as the percentage of cells that has excluded trypan blue. Cells incubated with Cisplatin as above are also diluted into 0.1% agar and allowed to grow for 2 weeks when colonies are counted.