Drug-induced Modulation of Heat Shock Protein HSPB1 in an Ovarian Cancer Cell Model.

BACKGROUND: Heat-shock protein HSPB1 (alternative name HSP27) plays a pivotal role in cell survival pathways, apoptosis, metastasis and has been frequently linked to treatment resistance in ovarian cancer (OC) and other malignancies. Characteristic HSPB1 induction in different solid tumors is often caused by cytotoxic agents.

MATERIALS AND METHODS: An in vitro OC cell model system was established to characterize resistance mechanisms during chemotherapy. Human OC cell lines OVCAR-3, SK-OV-3 and TOV-21G were treated with paclitaxel or carboplatin. Cellular growth was analyzed by cell counting. Intra- and extracellular HSPB1 concentrations were assessed by western blot and enzyme-linked immunosorbent assays.

RESULTS: Incubation with paclitaxel, and with carboplatin significantly reduced cell growth without a definitive increase of intracellular HSPB1 expression. HSPB1 demonstrated drug-inducible secretion into the extracellular compartment.

CONCLUSION: Despite its current lack of analysis in patient samples, serum soluble HSPB1 may function as a specific biomarker for monitoring response to chemotherapy in patients with OC.