Cisplatin and Vinorelbine -Mediated Electrochemotherapeutic Approach Against Multidrug Resistant Small Cell Lung Cancer (H69AR) In Vitro.

Abstract

Small cell lung cancer (SCLC) originates from neuroendocrine branchial cells (15-20%). It is regarded as distinct from other lung cancers due to its biological and clinical features. In most cases of SCLC, surgery or radiotherapy alone is not an effective cure. The aim of our study was to examine the cytotoxic effects of chemotherapy supported by electroporation (EP) on a resistant SCLC model, in vitro. The multidrug resistant small lung cell line H69AR was used to evaluate the cytotoxic effects of cisplatin (CPPD) and vinorelbine (Navirel®; NAV) at lower doses when used with EP. Cells were treated with different concentrations of CPPD and NAV, alone or in combination with the following EP parameters: 400-1200 V/cm, 8 pulses of 100 μs duration, at 1Hz. The cell viability was estimated by MTT assay after 24 and 48 h. Apoptotic cells were detected by neutral comet assay and immunofluorescence assay with PARP-6. CPPD and NAV alone showed a dose-dependent effect on cell viability. Cytostatic drugs combined with EP revealed increased anticancer activity. Lower doses of CPPD or NAV delivered by EP were as effective as higher doses of these drugs without EP. The electrochemotherapeutic protocols increased the number of apoptotic cells and increased immunoreactivity of PARP-6. Our results indicated higher sensitivity of H69AR cells to NAV supported by EP. In SCLC cells, an increased anticancer activity was potentiated by exposure of cells to high intensity electric pulses and low drug doses. It is suggested that this method could be effectively applied in the treatment of lung cancer.