Book of abstract 2008

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Chemotherapy-induced cell death and its assessment in vivo
Engin Ulukaya
Dept. of Biochemistry, Medical School of Uludag University, 16059 Bursa, Turkey
Oncologists are always concerned about whether or not chemotherapy succesfully kills the
cancer cells in their patients. It is thought that the mode of cell death could be apoptosis,
which is also called programmed cell death, although the other cell death modes may also
be possible. One of the characteristics of apoptosis is the distruption of cytoskeleton in
which cytokeratin 18 constitutes the major part. Once cells have undergone apoptosis,
cytokeratin 18 is cleaved at certain positions by apoptosis-spesific proteases, also known as
caspases. After the cleavage, a neo-epitope is formed. Caspase-cleaved cytokeratin 18 (M30
antigen) is released into blood stream, following apoptosis. This neo-epitope is recognized
by so-called M30 antibody. Using an ELISA assay for M30 antigen, it is possible to detect
the soluble M30 antigen in serum of patients prior to and after the chemotherapy, which
allows to estimate the efficacy of the drugs in vivo. In our recent study with lung cancer
patients (Ulukaya et al, 2007), we found that M30 antigen level statistically significantly
increased after the application of chemotherapy. Likewise, it elevated in breast cancer
patients following chemotherapy as well. The basal levels of M30 antigen may also have
a potential to use it as a predictor of the prognosis of patients. M30 antigen seems to be a
favorable novel serum marker in the better management of cancer patients although more
clinical studies are required.