Abstract 2044: Lin neg Sca-1high CD49f high prostate cancer cells derived from Hi-Myc mice are tumor-initiating cells with basal-epithelial characteristics and differentiation potential in vitro and in vivo
Authors: Blando Jorge M. , Saha Achinto , Fernandez Irina , Kiguchi Kaoru , DiGiovanni John 
Published: May 2015

Cancer stem cells (CSCs) are proposed to play a key role in development and survival of many tumor types. In this study, we have isolated a population of cells that possess characteristics of CSC both in-vitro and in-vivo from prostate tumors of one-year-old Hi-Myc mice. These cells, called HMVP2, are LinnegSca-1highCD49f high by flow cytometry (FC) analyses, with high CD44 and CD29 expression. Immunofluorescence (IF) analysis of HMVP2 cells showed positive staining for CK14, Sca-1 and CD49f while staining negative for CK8, suggesting basal-epithelial characteristics. HMVP2 cells were able to form spheroids and both cells and spheres were able to generate allograft tumors following s.c injection. After four days of culture, FC analysis of the spheres revealed a gradual transition from LinnegSca-1highCD49f high expression to LinnegSca-1lowCD49f low indicative of possible differentiation to a more luminal-epithelial cell-type, while a part of the cells retained the original Linneg Sca-1highCD49f high expression. Moreover, additional cell subpopulations expressing Linpos markers, and changes on the levels of CD34, CD44 and CD29 on LinnegSca-1highCD49f high and LinnegSca-1lowCD49f low cells were also confirmed by FC, suggesting a differentiation to a hematopoietic/vessel and pre-adipocyte cell-subtypes. IF staining of the spheroids and grafted tumors revealed staining for Sca-1, CD49f, CK8 and CK14 also verifying the presence of two or more cell subpopulations. Two additional cell lines (HMVP2-A1 and HMVP2-A2) were isolated from the original grafted tumors following in vivo passage also showing CSC characteristics. Concurrently, we also isolated cells from the VP of 6 months old Hi-Myc mice (HMVP1) and FVB/N NTg mice (NMVP) having less aggressive growth properties compared to the other three cell lines. Expression of the AR was lower in HMVP2, HMVP2A1 and HMVP2A2 cells compared to NMVP and HMVP1 cells. The expression of vimentin was increased in cells from Hi-Myc mice compared to the NMVP cells. Collectively, our data suggest that single cells derived from prostate tumors in Hi-Myc mice, showing basal-epithelial progenitor characteristics, can differentiate to mixed cell populations and form tumors. These cells provide novel tools for studying tumor development as wells for analysis of novel preventive and/or therapeutic agents for prostate cancer.

Citation Format: Jorge M. Blando, Achinto Saha, Irina Fernandez, Kaoru Kiguchi, John DiGiovanni. Lin neg Sca-1high CD49f high prostate cancer cells derived from Hi-Myc mice are tumor-initiating cells with basal-epithelial characteristics and differentiation potential in vitro and in vivo. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2044. doi:10.1158/1538-7445.AM2014-2044