Browsing by Author "Negrete, Marcos"

Now showing 1 - 4 of 4
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    Chromatin Remodeling of Colorectal Cancer Liver Metastasis is Mediated by an HGF-PU.1-DPP4 Axis.
    (Advanced science (Weinheim, Baden-Wurttemberg, Germany), 2021-10) Wang, Lihua; Wang, Ergang; Prado Balcazar, Jorge; Wu, Zhenzhen; Xiang, Kun; Wang, Yi; Huang, Qiang; Negrete, Marcos; Chen, Kai-Yuan; Li, Wei; Fu, Yujie; Dohlman, Anders; Mines, Robert; Zhang, Liwen; Kobayashi, Yoshihiko; Chen, Tianyi; Shi, Guizhi; Shen, John Paul; Kopetz, Scott; Tata, Purushothama Rao; Moreno, Victor; Gersbach, Charles; Crawford, Gregory; Hsu, David; Huang, Emina; Bu, Pengcheng; Shen, Xiling
    Colorectal cancer (CRC) metastasizes mainly to the liver, which accounts for the majority of CRC-related deaths. Here it is shown that metastatic cells undergo specific chromatin remodeling in the liver. Hepatic growth factor (HGF) induces phosphorylation of PU.1, a pioneer factor, which in turn binds and opens chromatin regions of downstream effector genes. PU.1 increases histone acetylation at the DPP4 locus. Precise epigenetic silencing by CRISPR/dCas9KRAB or CRISPR/dCas9HDAC revealed that individual PU.1-remodeled regulatory elements collectively modulate DPP4 expression and liver metastasis growth. Genetic silencing or pharmacological inhibition of each factor along this chromatin remodeling axis strongly suppressed liver metastasis. Therefore, microenvironment-induced epimutation is an important mechanism for metastatic tumor cells to grow in their new niche. This study presents a potential strategy to target chromatin remodeling in metastatic cancer and the promise of repurposing drugs to treat metastasis.
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    Intravital imaging of mouse embryos
    (Science, 2020-04-10) Huang, Qiang; Cohen, Malkiel A; Alsina, Fernando C; Devlin, Garth; Garrett, Aliesha; McKey, Jennifer; Havlik, Patrick; Rakhilin, Nikolai; Wang, Ergang; Xiang, Kun; Mathews, Parker; Wang, Lihua; Bock, Cheryl; Ruthig, Victor; Wang, Yi; Negrete, Marcos; Wong, Chi Wut; Murthy, Preetish KL; Zhang, Shupei; Daniel, Andrea R; Kirsch, David G; Kang, Yubin; Capel, Blanche; Asokan, Aravind; Silver, Debra L; Jaenisch, Rudolf; Shen, Xiling
    Embryonic development is a complex process that is unamenable to direct observation. In this study, we implanted a window to the mouse uterus to visualize the developing embryo from embryonic day 9.5 to birth. This removable intravital window allowed manipulation and high-resolution imaging. In live mouse embryos, we observed transient neurotransmission and early vascularization of neural crest cell (NCC)–derived perivascular cells in the brain, autophagy in the retina, viral gene delivery, and chemical diffusion through the placenta. We combined the imaging window with in utero electroporation to label and track cell division and movement within embryos and observed that clusters of mouse NCC-derived cells expanded in interspecies chimeras, whereas adjacent human donor NCC-derived cells shrank. This technique can be combined with various tissue manipulation and microscopy methods to study the processes of development at unprecedented spatiotemporal resolution.
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    Patient-derived micro-organospheres enable clinical precision oncology.
    (Cell stem cell, 2022-06) Ding, Shengli; Hsu, Carolyn; Wang, Zhaohui; Natesh, Naveen R; Millen, Rosemary; Negrete, Marcos; Giroux, Nicholas; Rivera, Grecia O; Dohlman, Anders; Bose, Shree; Rotstein, Tomer; Spiller, Kassandra; Yeung, Athena; Sun, Zhiguo; Jiang, Chongming; Xi, Rui; Wilkin, Benjamin; Randon, Peggy M; Williamson, Ian; Nelson, Daniel A; Delubac, Daniel; Oh, Sehwa; Rupprecht, Gabrielle; Isaacs, James; Jia, Jingquan; Chen, Chao; Shen, John Paul; Kopetz, Scott; McCall, Shannon; Smith, Amber; Gjorevski, Nikolche; Walz, Antje-Christine; Antonia, Scott; Marrer-Berger, Estelle; Clevers, Hans; Hsu, David; Shen, Xiling
    Patient-derived xenografts (PDXs) and patient-derived organoids (PDOs) have been shown to model clinical response to cancer therapy. However, it remains challenging to use these models to guide timely clinical decisions for cancer patients. Here, we used droplet emulsion microfluidics with temperature control and dead-volume minimization to rapidly generate thousands of micro-organospheres (MOSs) from low-volume patient tissues, which serve as an ideal patient-derived model for clinical precision oncology. A clinical study of recently diagnosed metastatic colorectal cancer (CRC) patients using an MOS-based precision oncology pipeline reliably assessed tumor drug response within 14 days, a timeline suitable for guiding treatment decisions in the clinic. Furthermore, MOSs capture original stromal cells and allow T cell penetration, providing a clinical assay for testing immuno-oncology (IO) therapies such as PD-1 blockade, bispecific antibodies, and T cell therapies on patient tumors.
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    Rapid tissue prototyping with micro-organospheres.
    (Stem cell reports, 2022-09) Wang, Zhaohui; Boretto, Matteo; Millen, Rosemary; Natesh, Naveen; Reckzeh, Elena S; Hsu, Carolyn; Negrete, Marcos; Yao, Haipei; Quayle, William; Heaton, Brook E; Harding, Alfred T; Bose, Shree; Driehuis, Else; Beumer, Joep; Rivera, Grecia O; van Ineveld, Ravian L; Gex, Donald; DeVilla, Jessica; Wang, Daisong; Puschhof, Jens; Geurts, Maarten H; Yeung, Athena; Hamele, Cait; Smith, Amber; Bankaitis, Eric; Xiang, Kun; Ding, Shengli; Nelson, Daniel; Delubac, Daniel; Rios, Anne; Abi-Hachem, Ralph; Jang, David; Goldstein, Bradley J; Glass, Carolyn; Heaton, Nicholas S; Hsu, David; Clevers, Hans; Shen, Xiling
    In vitro tissue models hold great promise for modeling diseases and drug responses. Here, we used emulsion microfluidics to form micro-organospheres (MOSs), which are droplet-encapsulated miniature three-dimensional (3D) tissue models that can be established rapidly from patient tissues or cells. MOSs retain key biological features and responses to chemo-, targeted, and radiation therapies compared with organoids. The small size and large surface-to-volume ratio of MOSs enable various applications including quantitative assessment of nutrient dependence, pathogen-host interaction for anti-viral drug screening, and a rapid potency assay for chimeric antigen receptor (CAR)-T therapy. An automated MOS imaging pipeline combined with machine learning overcomes plating variation, distinguishes tumorspheres from stroma, differentiates cytostatic versus cytotoxic drug effects, and captures resistant clones and heterogeneity in drug response. This pipeline is capable of robust assessments of drug response at individual-tumorsphere resolution and provides a rapid and high-throughput therapeutic profiling platform for precision medicine.