Use of High-Throughput Technology and Immunophenotyping To Assess the Cytotoxic and Anti-Cancer Stem Cell Activity of Simvastatin in Various Malignant Neoplasms
Valeria B De Souza, Gilberto C Franchi, Jr, Andre L Renno, Philipi C De Souza, Cristielle P Freitas, Marina Pavanello, Alexandre E Nowill, Natalia GM Schenka, Rafael M Rocha, Glauce A Pinto, Fernando A Soares, Jose Vassallo, Andre A Schenka. State University of Campinas (UNICAMP), Campinas, SP, Brazil; Hospital A. C. Camargo/Fund. Antônio Prudente, Sao Paulo, Brazil
Background: A novel paradigm in cancer treatment is now emerging, whereby new antineoplastic agents are being searched among drugs currently used in choronic metabolic diseases. One of such promising agents is simvastatin, a competitive inhibitor of HMG-CoA redutase, widely used in the prevention of cardiovascular diseases. Simvastatin has recently been associated to anti-proliferation actions in breast, colon and central nervous system malignancies. Nonetheless, the extension of such actions in terms of tumor type and their underlying mechanisms remain unclear, particularly concerning a putative inhibitory effect on cancer stem cells (CSCs), currently a priority therapeutic target.
Design: Simvastatin (purity>95%) was tested in 22 human cancer cell lines, including carcinomas of prostatic (PC3), ovarian (OVCAR), cervix uteri (HELA), lung (NCI) and breast (MCF7) origins, osteosarcomas (HOS, U20S) and glioblastomas (U-87, U138MG). These cells were automatically disposed in 96-well plates and submitted to different drug concentrations using Eppendorf 's epMotion equipment. After 48h of incubation, cell viability was determined by Mosmann MTT growth assay, the results expressed as IC50 and compared to those of a control drug (doxorubicin). MCF7 cell line was further subjected to immunophenotyping for CSC markers (CD24, CD44, CD117, CD133 and Oct4).
Results: The lowest concentration of simvastatin achieving IC50 (0.8ug/mL) was seen in the U138MG glioma cell line. In most of the remaining cell lines, simvastatin concentrations reaching growth inhibition were close to those of the control drug. PC3 and U20S were found to be less sensitive but still responsive to simvastatin. Treatment of MCF7cells with simvastatin resulted in statistically significant reductions (12-97%) in the expression of some of the CSC markers (CD24, CD44 and CD117).
Conclusions: In vitro antineoplastic actions of simvastatin are variable among different cell lines and most significant in glial, ovarian, cervical, and osteogenic malignancies. In MCF7 cells, part of the anti-tumoral effect could be explained by a clear reduction in the number of malignant cells expressing CSC markers. Studies on the antineoplastic and anti-CSCs properties of statins should now proceed to in vivo models.
Wednesday, March 21, 2012 9:30 AM
Poster Session V # 262, Wednesday Morning