Poly r(C) Binding Protein-1 is Central to Maintenance of Cancer Stem Cells in Prostate Cancer Cells

• Main Authors: Qi Chen, Zhi-kang Cai, Yan-bo Chen, Meng Gu, Da-chao Zheng, Juan Zhou, Zhong Wang
• Format: Article
• Language: English
• Published: Cell Physiol Biochem Press GmbH & Co KG 2015-02-01
• Series: Cellular Physiology and Biochemistry
• Subjects: Prostate cancer; Poly r(C) binding protein-1; PCBP1; Stemness; Metastasis; Cancer stem cells
• Online Access: http://www.karger.com/Article/FullText/373931

Aims: To investigate global proteomic changes induced in CD44+CD24- stem cells isolated from the prostate cancer cell lines, LNCaP and DU145, post prolonged TGF-β treatment in order to understand underlying mechanisms that promote stemness in prostate cancer cells. Methods: CD44+CD133+α2β1Integrin+CD24- population was isolated from mock or TGF-β treated (7 days) prostate cancer cell line, LNCaP, through fluorescent activated cell sorting. Cell lysates were obtained from the ±TGF-β cell population and proteomics profiling (MS/MS) was performed by mass spectrometry. Relative enrichment or depletion in the CD44+CD24-population post-TGF-β treatment was determined relative to mock-treated CD44+CD24- cells post normalization to GAPDH expression levels. Results obtained from MS/MS were validated using immunoblotting. Functional validation of one putative regulator was performed using gain-of-function strategy to investigate its role in rendering stemness in LNCaP and DU145 cells in vitro and in promoting tumorigenicity in vivo. Results: TGF-β treatment caused significant enrichment of CD44+CD24- population in LNCaP cells (22.35 ± 0.94% in mock treated vs 95.23 ± 2.34% in TGF-β treated cells; P in vitro soft agar colony formation and in vivo xenograft assays. Conclusion: Our proteomic profiling and subsequent validation indicate that PCBP1 is central to CSCs enrichment and functionality in prostate cancer.