Inhibition of the Insulin-Like Growth Factor-1 Receptor Enhances Effects of Simvastatin on Prostate Cancer Cells in Co-Culture with Bone
2013 (English)In: Cancer microenvironment : official journal of the International Cancer Microenvironment Society, ISSN 1875-2292, Vol. 6, no 3, 231-240 p.Article in journal (Refereed) Published
Prostate cancer (PC) bone metastases show weak responses to conventional therapies. Bone matrix is rich in growth factors, with insulin-like growth factor-1 (IGF-1) being one of the most abundant. IGF-1 acts as a survival factor for tumor cells and we speculate that bone-derived IGF-1 counteracts effects of therapies aimed to target bone metastases and, consequently, that therapeutic effects could be enhanced if given in combination with IGF-1 receptor (IGF-1R) inhibitors. Simvastatin inhibits the mevalonate pathway and has been found to induce apoptosis of PC cells. The aims of this study were to confirm stimulating effects of bone-derived IGF-1 on PC cells and to test if IGF-1R inhibition enhances growth inhibitory effects of simvastatin on PC cells in a bone microenvironment. The PC-3 and 22Rv1 tumor cell lines showed significantly induced cell growth when co-cultured with neonatal mouse calvarial bones. The tumor cell IGF-1R was activated by calvariae-conditioned media and neutralization of bone-derived IGF-1 abolished the calvarium-induced PC-3 cell growth. Treatment of PC-3 and 22Rv1 cells with simvastatin, or the IGF-1R inhibitor NVP-AEW541, reduced tumor cell numbers and viability, and induced apoptosis. Combined simvastatin and NVP-AEW541 treatment resulted in enhanced growth inhibitory effects compared to either drug given alone. Effects of simvastatin involved down-regulation of IGF-1R in PC-3 and of constitutively active androgen receptor variants in 22Rv1 cells. In conclusion, we suggest that IGF-1 inhibition may be a way to strengthen effects of apoptosis-inducing therapies on PC bone metastases; a possibility that needs to be further tested in pre-clinical models.
Place, publisher, year, edition, pages
Springer, 2013. Vol. 6, no 3, 231-240 p.
Cancer and Oncology
IdentifiersURN: urn:nbn:se:umu:diva-65834DOI: 10.1007/s12307-013-0129-zPubMedID: 23335094OAI: oai:DiVA.org:umu-65834DiVA: diva2:604937