Immunoprecipitation-based high performance liquid chromatography (IP-HPLC) is a type of modified enzyme-linked immunosorbent assay (ELISA) that uses protein A/G (or antibody)-conjugated beads instead of the antibody-conjugated wells used in ELISA. In order to determine the fidelity of IP-HPLC, the author used 83 antisera to identify protein expression changes caused by cisplatin treatment in KB human oral cancer cells. KB cells were cultured for 12 or 24 hours with 10 ug/mL cisplatin. The results obtained by IP-HPLC were comparable with published cisplatin data, although ELISA was not conducted in the present study. Cisplatin dominantly reduced the levels of proteins associated with cell proliferation, transcription factors, growth factors, cytoskeletal proteins, and cellular differentiating factors, but on the other hand, apoptosis-related factors, oncogenes, and protective proteins were usually up-regulated, presumably to address cisplatin-induced DNA damage. In particular, cisplatin directly inactivated genomic DNA by down-regulating histone H1 and demethylase and by up-regulating deacetylase. Cisplatin also rapidly induced p53 overexpression and mitochondria-mediated endogenous apoptosis occurred after 12 hours of cisplatin treatment, although this was almost completely replaced by FASL/FAS-mediated exogenous apoptosis after 24 hours. This preliminary study was conducted to investigate the anticancer effect of cisplatin on the KB human oral cancer cells and to determine the fidelity of IP-HPLC data. It was concluded that IP-HPLC is useful for identifying profile changes of genome wide essential proteins and signaling changes of major molecular pathways.

• Yeon Sook Kim(Department of Dental Hygiene, College of Health Sciences, Cheongju University) | 김연숙 Correspondence