@article{1cfca2b2938942b0967b48aa72e7755b,
title = "Embryonic Barcoding of Equipotent Mammary Progenitors Functionally Identifies Breast Cancer Drivers",
abstract = "Identification of clinically relevant drivers of breast cancers in intact mammary epithelium is critical for understanding tumorigenesis yet has proven challenging. Here, we show that intra-amniotic lentiviral injection can efficiently transduce progenitor cells of the adult mammary gland and use that as a platform to functionally screen over 500 genetic lesions for functional roles in tumor formation. Targeted progenitors establish long-term clones of both luminal and myoepithelial lineages in adult animals, and via lineage tracing with stable barcodes, we found that each mouse mammary gland is generated from a defined number of ∼120 early progenitor cells that expand uniformly with equal growth potential. We then designed an in vivo screen to test genetic interactions in breast cancer and identified candidates that drove not only tumor formation but also molecular subtypes. Thus, this methodology enables rapid and high-throughput cancer driver discovery in mammary epithelium. Ying and Beronja employ lentiviral targeting and quantitative lineage tracing of murine mammary epithelium to establish that early progenitors are bi-potent and with equal long-term growth potential. Using these insights, they design a large-scale genetic screen that can identify functional drivers of tumor initiation and subtype shift in breast cancer.",
keywords = "barcoded lentivirus, breast cancer driver, ectodermal mammary progenitor, in vivo screen, in-utero injection, patient derived lesion, quantitative lineage tracing",
author = "Zhe Ying and Slobodan Beronja",
note = "Funding Information: We thank W. Phillips for sharing the inducible Pik3ca H1047R mouse, C. Ghajar and A. Hsieh for critical reading of the manuscript, Comparative Medicine (AAALAC accredited; G. Roble, director) for care of mice in accordance with NIH guidelines, Genomics (J. Delrow, director) for sequencing, Scientific Imaging (J. Vazquez, director) for advice, and Flow Cytometry (A. Berger, director) for FACS. This research was funded by the NIH / NCI Cancer Center Support Grant P30 CA015704 , Safeway Early Career Award in Cancer Research , and the NIH R01-AR070780 (S.B.), and Thomsen Family Fellowship and the NIH K99-DE029229 (Z.Y.). Funding Information: We thank W. Phillips for sharing the inducible Pik3caH1047R mouse, C. Ghajar and A. Hsieh for critical reading of the manuscript, Comparative Medicine (AAALAC accredited; G. Roble, director) for care of mice in accordance with NIH guidelines, Genomics (J. Delrow, director) for sequencing, Scientific Imaging (J. Vazquez, director) for advice, and Flow Cytometry (A. Berger, director) for FACS. This research was funded by the NIH/NCI Cancer Center Support Grant P30 CA015704, Safeway Early Career Award in Cancer Research, and the NIH R01-AR070780 (S.B.), and Thomsen Family Fellowship and the NIH K99-DE029229 (Z.Y.). Z.Y. and S.B. conceived the study and designed the experiments. Z.Y. performed all experiments and data analyses. Z.Y. and S.B. wrote the paper. The authors declare no competing interests. Publisher Copyright: {\textcopyright} 2020 Elsevier Inc.",
year = "2020",
month = mar,
day = "5",
doi = "10.1016/j.stem.2020.01.009",
language = "English",
volume = "26",
pages = "403--419.e4",
journal = "Cell Stem Cell",
issn = "1934-5909",
publisher = "Cell Press",
number = "3",
}