Identification of Selective Inhibitors of Cancer Stem Cells by High-Throughput Screening

Screens for agents that specifically kill epithelial cancer stem cells (CSCs) have not been possible due to the rarity of these cells within tumor cell populations and their relative instability in culture. We describe here an approach to screening for agents with epithelial CSC-specific toxicity. We implemented this method in a chemical screen and discovered compounds showing selective toxicity for breast CSCs. One compound, salinomycin, reduces the proportion of CSCs by >100-fold relative to paclitaxel, a commonly used breast cancer chemotherapeutic drug. Treatment of mice with salinomycin inhibits mammary tumor growth in vivo and induces increased epithelial differentiation of tumor cells. In addition, global gene expression analyses show that salinomycin treatment results in the loss of expression of breast CSC genes previously identified by analyses of breast tissues isolated directly from patients. This study demonstrates the ability to identify agents with specific toxicity for epithelial CSCs.

[1]  M. Caligiuri,et al.  A cell initiating human acute myeloid leukaemia after transplantation into SCID mice , 1994, Nature.

[2]  Irving L. Weissman,et al.  Association of reactive oxygen species levels and radioresistance in cancer stem cells , 2009, Nature.

[3]  S. Morrison,et al.  Prospective identification of tumorigenic breast cancer cells , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[4]  Mark W. Dewhirst,et al.  Glioma stem cells promote radioresistance by preferential activation of the DNA damage response , 2006, Nature.

[5]  Anna E. Lokshin,et al.  Drug-Selected Human Lung Cancer Stem Cells: Cytokine Network, Tumorigenic and Metastatic Properties , 2008, PloS one.

[6]  Alan Ashworth,et al.  Stem cells and breast cancer: A field in transit , 2003, Nature Reviews Cancer.

[7]  M. Diehn,et al.  Cancer stem cells and radiotherapy: new insights into tumor radioresistance. , 2006, Journal of the National Cancer Institute.

[8]  E. Lander,et al.  Loss of E-cadherin promotes metastasis via multiple downstream transcriptional pathways. , 2008, Cancer research.

[9]  Susan G Hilsenbeck,et al.  Intrinsic resistance of tumorigenic breast cancer cells to chemotherapy. , 2008, Journal of the National Cancer Institute.

[10]  Daniel Medina,et al.  Identification of tumor-initiating cells in a p53-null mouse model of breast cancer. , 2008, Cancer research.

[11]  L. Ellis,et al.  Chronic Oxaliplatin Resistance Induces Epithelial-to-Mesenchymal Transition in Colorectal Cancer Cell Lines , 2006, Clinical Cancer Research.

[12]  R. Beroukhim,et al.  Molecular definition of breast tumor heterogeneity. , 2007, Cancer cell.

[13]  P. Dalerba,et al.  Identification of pancreatic cancer stem cells. , 2006, Cancer research.

[14]  L. Ricci-Vitiani,et al.  Identification and expansion of human colon-cancer-initiating cells , 2007, Nature.

[15]  Pablo Tamayo,et al.  Gene set enrichment analysis: A knowledge-based approach for interpreting genome-wide expression profiles , 2005, Proceedings of the National Academy of Sciences of the United States of America.

[16]  Charlotte Kuperwasser,et al.  Human breast cancer cell lines contain stem-like cells that self-renew, give rise to phenotypically diverse progeny and survive chemotherapy , 2008, Breast Cancer Research.

[17]  M. Hofker.  Faculty Opinions recommendation of PGC-1alpha-responsive genes involved in oxidative phosphorylation are coordinately downregulated in human diabetes. , 2003 .

[18]  Jean-Philippe Brunet,et al.  The melanocyte differentiation program predisposes to metastasis after neoplastic transformation , 2005, Nature Genetics.

[19]  W. Hahn,et al.  Human breast cancer cells generated by oncogenic transformation of primary mammary epithelial cells. , 2001, Genes & development.

[20]  Carlos Caldas,et al.  Molecular heterogeneity of breast carcinomas and the cancer stem cell hypothesis , 2007, Nature Reviews Cancer.

[21]  W. Woodward,et al.  WNT/β-catenin mediates radiation resistance of mouse mammary progenitor cells , 2007, Proceedings of the National Academy of Sciences.

[22]  Cynthia Hawkins,et al.  Identification of a cancer stem cell in human brain tumors. , 2003, Cancer research.

[23]  S. Ramaswamy,et al.  Twist, a Master Regulator of Morphogenesis, Plays an Essential Role in Tumor Metastasis , 2004, Cell.

[24]  J. Rich,et al.  Survival of the fittest: cancer stem cells in therapeutic resistance and angiogenesis. , 2008, Journal of clinical oncology : official journal of the American Society of Clinical Oncology.

[25]  A. Allan,et al.  Cancer stem cells: implications for the progression and treatment of metastatic disease , 2007, Journal of cellular and molecular medicine.

[26]  G. Dontu,et al.  In vitro propagation and transcriptional profiling of human mammary stem/progenitor cells. , 2003, Genes & development.

[27]  G. Sherlock,et al.  The prognostic role of a gene signature from tumorigenic breast-cancer cells. , 2007, The New England journal of medicine.

[28]  Michael Dean,et al.  Tumour stem cells and drug resistance , 2005, Nature Reviews Cancer.

[29]  G. Cavet,et al.  Epithelial versus Mesenchymal Phenotype Determines In vitro Sensitivity and Predicts Clinical Activity of Erlotinib in Lung Cancer Patients , 2005, Clinical Cancer Research.

[30]  E. Brown,et al.  Epithelial to mesenchymal transition is a determinant of sensitivity of non-small-cell lung carcinoma cell lines and xenografts to epidermal growth factor receptor inhibition. , 2005, Cancer research.

[31]  J. Massagué,et al.  Beyond tumorigenesis: cancer stem cells in metastasis , 2007, Cell Research.

[32]  Wenjun Guo,et al.  The Epithelial-Mesenchymal Transition Generates Cells with Properties of Stem Cells , 2008, Cell.