Abstract 4476: The effect of electrochemotherapy on metastatic potential of human melanoma cells SK-Mel28

Abstract

Abstract Electrochemotherapy is a local treatment, combining chemotherapy and application of electric pulses to the tumour. Electrochemotherapy with bleomycin or cisplatin has demonstrated its effectiveness in controlling local tumour growth in the treatment of malignant melanoma and is proposed as one of the treatment options for in-transit melanoma metastases in Europe. An important aspect of successful treatment is prevention of metastasis, however, it is known that metastasis can be induced by different treatment modalities. Alterations in tumour microenvironment caused by surgery or radiation therapy, can lead to increased formation of metastasis. Furthermore, formation of metastases can be directly linked to migratory potential of the cells. Although electrochemotherapy is now routinely used for treatment of various cancers in many cancer centres, the effect of electrochemotherapy on the metastatic potential of tumour cells is not known. Therefore, the aim of this study was to evaluate the effect of electrochemotherapy with bleomycin and cisplatin on the metastatic potential of human malignant melanoma cells. Human malignant melanoma cells SK-MEL 28 were treated by electrochemotherapy with a range of bleomycin concentrations from 0.01 nM to 1μM and cisplatin concentrations from 2 to 80 μg/mL. SK-MEL 28 cells that were viable 48 h after electrochemotherapy were tested for their metastatic potential by ability to migrate and invade through Matrigel coated porous membrane. In addition, cell adhesion and proliferation using MTS assay were also tested. Furthemore, RNA was isolated from the cells 16 h after each treatment and differentially expressed genes were investigated by microarray analysis to evaluate the effect of electrochemotherapy with bleomycin or cisplatin on expression of genes involved in the development of cancer. The Gene Ontology Tree Machine program was used for gene enrichment analysis. Migration and invasion of melanoma cells that survived 48h after electrochemotherapy with bleomycin or cisplatin were not changed compared to control untreated cells. Also, there were no changes observed in cell adhesion on Matrigel. Gene expression analysis demonstrated that a very low number of genes were differentially expressed after electrochemotherapy with either bleomycin or cisplatin. Specifically, the expression of metastasis promoting genes was not increased after electrochemotherapy. Our data suggest that electrochemotherapy with bleomycin or cisplatin does not increase metastatic behaviour of human melanoma cells, having important clinical implication for safe use in treatment of melanoma metastases. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4476. doi:10.1158/1538-7445.AM2011-4476