Abstract 2689: Inhibition of metastasis of circulating tumor cells by extracellular matrix secreted by human embryonic cells

Abstract

Abstract We have previously demonstrated the increased metastatic potential of human prostate cancer PC-3 CTCs compared to their parental counterparts in both chick embryo and mouse models. In the present study, we tested the effects of human embryonic extracellular matrix (ECM), secreted by human embryonic cells including conditioned medium (CM) and a semi-solid form (hECM), on metastasis of PC-3 CTC in the chick embryo model. The chorioallentoic membrane (CAM) of 18 chicken embryos were inoculated with either 106 PC-3 human prostate cancer cells or PC-3 CTCs, both stably expressing GFP. Twelve hours later, embryos were divided into 6 groups each containing three embryos: PC-3 parental control; PC-3 + CM; PC-3 + hECM; CTC control; CTC + CM; and CTC+ hECM. Twelve hours following inoculation of the cells, a single dose of 100 μL of either treatment was given to the appropriate group. Embryo brains were removed on day 8 post-inoculations, and processed for cryo-sectioning, generating 3 slides of brain tissue per embryo taken at various depths. Imaging was performed using the IV-100 scanning laser microscope (Olympus Corp, Tokyo, Japan) in order to count metastatic foci. PC-3 controls had an average of 11.1 metastatic foci compared to 2.55 in the PC-3 + hECM group (p< 0.0001) and 2.76 in the PC-3 + CM group (p< 0.0001) The treatment showed even greater response on the CTC cells which an average of 30.9 metastatic foci in the CTC controls compared to 4.38 in the CTC + hECM group (p< 0.0001) and 4.18 in the CTC + CM group (p< 0.0001). Thus, human embryonic secreted ECM compound drastically decreased the metastatic potential of human prostate cancer CTCs in the chick embryo model. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2689. doi:1538-7445.AM2012-2689