The role of reactive oxygen species in cisplatin-induced apoptosis in human malignant testicular germ cell lines.
Testicular germ cell tumours (TGCT) are the most common solid tumour among young males. Whereas in 1970s, only 5% of patients with a metastatic testicular tumours survived their disease, these days 80% of patients treated by modern cisdiamminedichloroplatinum (cisplatin, CDDP)-based chemotherapy are cured. Although data are accumulating on the effect of the mitogen-activated protein kinase (MAPK) family on the CDDP-induced apoptosis in tumour cells, the mechanisms by which CDDP initiates apoptosis in TGCT are not completely understood. Applying Western blot and phosphorylated kinase-specific ELISA analyses, flow cytometry, blocking experiments, and morphological methods we sought here to define the MAPK pathway(s) involved in the CDDP-induced apoptosis in the human TGCT cell line NCCIT. Our experiments showed that within hours of CDDP application only the extracellular signal-regulated kinase (ERK) was dually phosphorylated and caspase-3 became active. Functional assays using chemical inhibitors demonstrated that the phosphorylation of ERK was mediated by reactive oxygen species in an Raf-1-independent manner and required the activation of caspase-3. Thus, our data suggest that CDDP mediates its apoptosis-inducing effect on the human malignant testicular germ cells, at least partially, through activation of the MEK-ERK signaling pathway in a ROS-dependent, Raf-1-independent manner.
Schweyer
S
S
Department of Pathology, University of Göttingen, D-37075 Göttingen, Germany. sswyer@med.uni-goettingen.de
Soruri
A
A
Heintze
A
A
Radzun
H J
HJ
Fayyazi
A
A
D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis; D015153:Blotting, Western; D002945:Cisplatin / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D020930:MAP Kinase Kinase Kinases / Q000494:pharmacology; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000494:pharmacology; D009373:Neoplasms, Germ Cell and Embryonal / Q000473:pathology*; D010766:Phosphorylation; D017382:Reactive Oxygen Species / Q000009:adverse effects*; D013736:Testicular Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D017382:Reactive Oxygen Species; D020930:MAP Kinase Kinase Kinases; D020929:Mitogen-Activated Protein Kinase Kinases; D002945:Cisplatin