Stem-like prostate cancer (PrCa) cells, also called PrCa stem cells (PrCSCs) or PrCa tumor-initiating cells (PrTICs), are considered to be involved in the mediation of tumor metastasis and may be responsible for the poor prognosis of PrCa patients. Currently, the methods for PrTIC sorting are mainly based on cell surface marker or side population (SP). However, the rarity of these sorted cells limits the investigation of the molecular mechanisms and therapeutic strategies targeting PrTICs. For PrTIC enrichment, we induced cancer stem cell (CSC) properties in PrCa cells by transducing three defined factors (OCT3/4, SOX2, and KLF4), followed by culture with conventional serum-containing medium. The CSC properties in the transduced cells were evaluated by proliferation, cell cycle, SP assay, drug sensitivity technology, in vivo tumorigenicity, and molecular marker analysis of PrCSCs compared with parental cells and spheroids. After culture with serum-containing medium for 8 days, the PrCa cells transduced with the three factors showed significantly enhanced CSC properties in terms of marker gene expression, sphere formation, chemoresistance to docetaxel, and tumorigenicity. The percentage of CD133+/CD44+ cells was ninefold higher in the transduced cell population than in the adherent PC3 cell population (2.25 ± 0.62 vs. 0.25 ± 0.12 %, respectively), and the SP increased to 1.22 ± 0.18 % in the transduced cell population, but was undetectable in the adherent population. This method can be used to obtain abundant PrTIC material and enables a complete understanding of PrTIC biology and development of novel therapeutic agents targeting PrTICs.
Tumor-initiating cells Enrichment Reprogramming Prostate cancer
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This study was supported by scientific research grants from the Pearl River Nova Program of Guangzhou (No. 2013J2200044), the National Natural Scientific Foundation of China (No. 81101559).
This work was supported by Grant  163 from Key Laboratory of Malignant Tumor Molecular Mechanism and Translational Medicine of Guangzhou Bureau of Science and Information Technology; Grant KLB09001 from the Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes.
O’Brien CA, Pollett A, Gallinger S, Dick JE. A human colon cancer cell capable of initiating tumour growth in immunodeficient mice. Nature. 2007;445:106–10.CrossRefPubMedGoogle Scholar
Boiko AD, Razorenova OV, van de Rijn M, Swetter SM, Johnson DL, Ly DP. Human melanoma-initiating cells express neural crest nerve growth factor receptor CD271. Nature. 2010;466:133–7.CrossRefPubMedPubMedCentralGoogle Scholar
Patrawala L, Calhoun T, Schneider-Broussard R, Li H, Bhatia B, Tang S, et al. Highly purified CD44+ prostate cancer cells from xenograft human tumors are enriched in tumorigenic and metastatic progenitor cells. Oncogene. 2006;25:1696–708.CrossRefPubMedGoogle Scholar
Rybak AP, Bristow RG, Kapoor A. Prostate cancer stem cells: deciphering the origins and pathways involved in prostate tumorigenesis and aggression. Oncotarget. 2015;6:1900–19.CrossRefPubMedGoogle Scholar
Oshima N, Yamada Y, Nagayama S, Kawada K, Hasegawa S, Okabe H, et al. Induction of cancer stem cell properties in colon cancer cells by defined factors. PLoS One. 2014;9:e101735.CrossRefPubMedPubMedCentralGoogle Scholar
Dubrovska A, Kim S, Salamone RJ, Walker JR, Maira SM, Garcia-Echeverria C, et al. The role of PTEN/Akt/PI3K signaling in the maintenance and viability of prostate cancer stem-like cell populations. Proc Natl Acad Sci U S A. 2009;106:268–73.CrossRefPubMedGoogle Scholar
Richardson GD, Robson CN, Lang SH, Neal DE, Maitland NJ, Collins AT. CD133, a novel marker for human prostatic epithelial stem cells. J Cell Sci. 2004;117:3539–45.CrossRefPubMedGoogle Scholar
Nishida S, Hirohashi Y, Torigoe T, Kitamura H, Takahashi A, Masumori N, et al. Gene expression profiles of prostate cancer stem cells isolated by aldehyde dehydrogenase activity assay. J Urol. 2012;188:294–9.CrossRefPubMedGoogle Scholar
Guzel E, Karatas OF, Duz MB, Solak M, Ittmann M, Ozen M. Differential expression of stem cell markers and ABCG2 in recurrent prostate cancer. Prostate. 2014;74:1498–505.CrossRefPubMedGoogle Scholar
Visvader JE, Lindeman GJ. Cancer stem cells in solid tumours: accumulating evidence and unresolved questions. Nat Rev Cancer. 2008;8:755–68.CrossRefPubMedGoogle Scholar
Jin M, Zhang T, Liu C, Badeaux MA, Liu B, Liu R, et al. MiRNA-128 suppresses prostate cancer by inhibiting BMI-1 to inhibit tumor-initiating cells. Cancer Res. 2014;74:4183–95.CrossRefPubMedPubMedCentralGoogle Scholar
Patrawala L, Calhoun T, Schneider-Broussard R, Zhou J, Claypool K, Tang DG. Side population is enriched in tumorigenic, stem-like cancer cells, whereas ABCG2+ and ABCG2-cancer cells are similarly tumorigenic. Cancer Res. 2005;65:6207–19.CrossRefPubMedGoogle Scholar
Zhang Y, Huang H, Zhou H, Du T, Zeng L, Cao Y, et al. Activation of nuclear factor kappaB pathway and downstream targets survivin and livin by SHARPIN contributes to the progression and metastasis of prostate cancer. Cancer. 2014;120:3208–18.CrossRefPubMedGoogle Scholar
Maitland NJ, Bryce SD, Stower MJ, Collins AT. Prostate cancer stem cells: a target for new therapies. Ernst Schering Found Symp Proc. 2006;5:155–79.Google Scholar
Goodell MA, Brose K, Paradis G, Conner AS, Mulligan RC. Isolation and functional properties of murine hematopoietic stem cells that are replicating in vivo. J Exp Med. 1996;183:1797–806.CrossRefPubMedGoogle Scholar
Dey D, Saxena M, Paranjape AN, Krishnan V, Giraddi R, Kumar MV, et al. Phenotypic and functional characterization of human mammary stem/progenitor cells in long term culture. PLoS One. 2009;4:e5329.CrossRefPubMedPubMedCentralGoogle Scholar
Fan X, Liu S, Su F, Pan Q, Lin T. Effective enrichment of prostate cancer stem cells from spheres in a suspension culture system. Urol Oncol. 2012;30:314–8.CrossRefPubMedGoogle Scholar
Takahashi K, Tanabe K, Ohnuki M, Narita M, Ichisaka T, Tomoda K, et al. Induction of pluripotent stem cells from adult human fibroblasts by defined factors. Cell. 2007;131:861–72.CrossRefPubMedGoogle Scholar
Moad M, Pal D, Hepburn AC, Williamson SC, Wilson L, Lako M, et al. A novel model of urinary tract differentiation, tissue regeneration, and disease: reprogramming human prostate and bladder cells into induced pluripotent stem cells. Eur Urol. 2013;64:753–61.CrossRefPubMedPubMedCentralGoogle Scholar