Professional Education

  • Doctor of Philosophy, University of California Irvine (2019)
  • Bachelor of Science, Calif Polytechnic State Univ, S.L.O. (2013)
  • PhD, University of California, Irvine (2019)
  • BS, Cal Poly San Luis Obispo (2013)

Stanford Advisors

Lab Affiliations

All Publications

  • LY6D marks pre-existing resistant basosquamous tumor subpopulations. Nature communications Haensel, D., Gaddam, S., Li, N. Y., Gonzalez, F., Patel, T., Cloutier, J. M., Sarin, K. Y., Tang, J. Y., Rieger, K. E., Aasi, S. Z., Oro, A. E. 2022; 13 (1): 7520


    Improved response to canonical therapies requires a mechanistic understanding of dynamic tumor heterogeneity by identifying discrete cellular populations with enhanced cellular plasticity. We have previously demonstrated distinct resistance mechanisms in skin basal cell carcinomas, but a comprehensive understanding of the cellular states and markers associated with these populations remains poorly understood. Here we identify a pre-existing resistant cellular population in naive basal cell carcinoma tumors marked by the surface marker LY6D. LY6D+ tumor cells are spatially localized and possess basal cell carcinoma and squamous cell carcinoma-like features. Using computational tools, organoids, and spatial tools, we show that LY6D+ basosquamous cells represent a persister population lying on a central node along the skin lineage-associated spectrum of epithelial states with local environmental and applied therapies determining the kinetics of accumulation. Surprisingly, LY6D+ basosquamous populations exist in many epithelial tumors, such as pancreatic adenocarcinomas, which have poor outcomes. Overall, our results identify the resistant LY6D+ basosquamous population as an important clinical target and suggest strategies for future therapeutic approaches to target them.

    View details for DOI 10.1038/s41467-022-35020-y

    View details for PubMedID 36473848

    View details for PubMedCentralID PMC9726704

  • Defining Epidermal Basal Cell States during Skin Homeostasis and Wound Healing Using Single-Cell Transcriptomics CELL REPORTS Haensel, D., Jin, S., Sun, P., Cinco, R., Dragan, M., Quy Nguyen, Cang, Z., Gong, Y., Vu, R., MacLean, A. L., Kessenbrock, K., Gratton, E., Nie, Q., Dai, X. 2020; 30 (11): 3932-+


    Our knowledge of transcriptional heterogeneities in epithelial stem and progenitor cell compartments is limited. Epidermal basal cells sustain cutaneous tissue maintenance and drive wound healing. Previous studies have probed basal cell heterogeneity in stem and progenitor potential, but a comprehensive dissection of basal cell dynamics during differentiation is lacking. Using single-cell RNA sequencing coupled with RNAScope and fluorescence lifetime imaging, we identify three non-proliferative and one proliferative basal cell state in homeostatic skin that differ in metabolic preference and become spatially partitioned during wound re-epithelialization. Pseudotemporal trajectory and RNA velocity analyses predict a quasi-linear differentiation hierarchy where basal cells progress from Col17a1Hi/Trp63Hi state to early-response state, proliferate at the juncture of these two states, or become growth arrested before differentiating into spinous cells. Wound healing induces plasticity manifested by dynamic basal-spinous interconversions at multiple basal transcriptional states. Our study provides a systematic view of epidermal cellular dynamics, supporting a revised "hierarchical-lineage" model of homeostasis.

    View details for DOI 10.1016/j.celrep.2020.02.091

    View details for Web of Science ID 000520843300030

    View details for PubMedID 32187560

    View details for PubMedCentralID PMC7218802

  • AP-1 and TGFSS cooperativity drives non-canonical Hedgehog signaling in resistant basal cell carcinoma. Nature communications Yao, C. D., Haensel, D., Gaddam, S., Patel, T., Atwood, S. X., Sarin, K. Y., Whitson, R. J., McKellar, S., Shankar, G., Aasi, S., Rieger, K., Oro, A. E. 2020; 11 (1): 5079


    Tumor heterogeneity and lack of knowledge about resistant cell states remain a barrier to targeted cancer therapies. Basal cell carcinomas (BCCs) depend on Hedgehog (Hh)/Gli signaling, but can develop mechanisms of Smoothened (SMO) inhibitor resistance. We previously identified a nuclear myocardin-related transcription factor (nMRTF) resistance pathway that amplifies noncanonical Gli1 activity, but characteristics and drivers of the nMRTF cell state remain unknown. Here, we use single cell RNA-sequencing of patient tumors to identify three prognostic surface markers (LYPD3, TACSTD2, and LY6D) which correlate with nMRTF and resistance to SMO inhibitors. The nMRTF cell state resembles transit-amplifying cells of the hair follicle matrix, with AP-1 and TGFSS cooperativity driving nMRTF activation. JNK/AP-1 signaling commissions chromatin accessibility and Smad3 DNA binding leading to a transcriptional program of RhoGEFs that facilitate nMRTF activity. Importantly, small molecule AP-1 inhibitors selectively target LYPD3+/TACSTD2+/LY6D+ nMRTF human BCCs ex vivo, opening an avenue for improving combinatorial therapies.

    View details for DOI 10.1038/s41467-020-18762-5

    View details for PubMedID 33033234

  • Wound healing in aged skin exhibits systems-level alterations in cellular composition and cell-cell communication CELL REPORTS Vu, R., Jin, S., Sun, P., Haensel, D., Nguyen, Q., Dragan, M., Kessenbrock, K., Nie, Q., Dai, X. 2022; 40 (5): 111155


    Delayed and often impaired wound healing in the elderly presents major medical and socioeconomic challenges. A comprehensive understanding of the cellular/molecular changes that shape complex cell-cell communications in aged skin wounds is lacking. Here, we use single-cell RNA sequencing to define the epithelial, fibroblast, immune cell types, and encompassing heterogeneities in young and aged skin during homeostasis and identify major changes in cell compositions, kinetics, and molecular profiles during wound healing. Our comparative study uncovers a more pronounced inflammatory phenotype in aged skin wounds, featuring neutrophil persistence and higher abundance of an inflammatory/glycolytic Arg1Hi macrophage subset that is more likely to signal to fibroblasts via interleukin (IL)-1 than in young counterparts. We predict systems-level differences in the number, strength, route, and signaling mediators of putative cell-cell communications in young and aged skin wounds. Our study exposes numerous cellular/molecular targets for functional interrogation and provides a hypothesis-generating resource for future wound healing studies.

    View details for DOI 10.1016/j.celrep.2022.111155

    View details for Web of Science ID 000842375100002

    View details for PubMedID 35926463

  • c-FOS drives reversible basal to squamous cell carcinoma transition. Cell reports Kuonen, F., Li, N. Y., Haensel, D., Patel, T., Gaddam, S., Yerly, L., Rieger, K., Aasi, S., Oro, A. E. 2021; 37 (1): 109774


    While squamous transdifferentiation within subpopulations of adenocarcinomas represents an important drug resistance problem, its underlying mechanism remains poorly understood. Here, using surface markers of resistant basal cell carcinomas (BCCs) and patient single-cell and bulk transcriptomic data, we uncover the dynamic roadmap of basal to squamous cell carcinoma transition (BST). Experimentally induced BST identifies activator protein 1 (AP-1) family members in regulating tumor plasticity, and we show that c-FOS plays a central role in BST by regulating the accessibility of distinct AP-1 regulatory elements. Remarkably, despite prominent changes in cell morphology and BST marker expression, we show using inducible model systems that c-FOS-mediated BST demonstrates reversibility. Blocking EGFR pathway activation after c-FOS induction partially reverts BST in vitro and prevents BST features in both mouse models and human tumors. Thus, by identifying the molecular basis of BST, our work reveals a therapeutic opportunity targeting plasticity as a mechanism of tumor resistance.

    View details for DOI 10.1016/j.celrep.2021.109774

    View details for PubMedID 34610301

  • Starve a cold, and perhaps a cancer. Nature cell biology Haensel, D., Oro, A. E. 2020

    View details for DOI 10.1038/s41556-020-0543-7

    View details for PubMedID 32587343

  • Intermediate cell states in epithelial-to-mesenchymal transition PHYSICAL BIOLOGY Sha, Y., Haensel, D., Gutierrez, G., Du, H., Dai, X., Nie, Q. 2019; 16 (2): 021001


    The transition of epithelial cells into a mesenchymal state (epithelial-to-mesenchymal transition or EMT) is a highly dynamic process implicated in various biological processes. During EMT, cells do not necessarily exist in 'pure' epithelial or mesenchymal states. There are cells with mixed (or hybrid) features of the two, which are termed as the intermediate cell states (ICSs). While the exact functions of ICS remain elusive, together with EMT it appears to play important roles in embryogenesis, tissue development, and pathological processes such as cancer metastasis. Recent single cell experiments and advanced mathematical modeling have improved our capability in identifying ICS and provided a better understanding of ICS in development and disease. Here, we review the recent findings related to the ICS in/or EMT and highlight the challenges in the identification and functional characterization of ICS.

    View details for DOI 10.1088/1478-3975/aaf928

    View details for Web of Science ID 000456276700001

    View details for PubMedID 30560804

    View details for PubMedCentralID PMC6602058

  • Ex Vivo Imaging and Genetic Manipulation of Mouse Hair Follicle Bulge Stem Cells. Methods in molecular biology (Clifton, N.J.) Haensel, D., McNeil, M. A., Dai, X. 2019; 1879: 15-29


    Stem cells that reside in the bulge of adult mouse hair follicles are a leading model of tissue stem cell research. Ex vivo culturing, molecular and cell biological characterizations, as well as genetic manipulation of fluorescence-activated cell sorting-isolated bulge stem cells offer a useful experimental pipeline to complement in vivo studies. Here we describe detailed methods for culturing, immunostaining, live cell imaging, and adenoviral infection of bulge stem cells for downstream applications such as in vitro clonal and in vivo patch assays.

    View details for DOI 10.1007/7651_2018_136

    View details for PubMedID 29478134

  • An Ovol2-Zeb1 transcriptional circuit regulates epithelial directional migration and proliferation EMBO REPORTS Haensel, D., Sun, P., MacLean, A. L., Ma, X., Zhou, Y., Stemmler, M. P., Brabletz, S., Berx, G., Plikus, M. V., Nie, Q., Brabletz, T., Dai, X. 2019; 20 (1)


    Directional migration is inherently important for epithelial tissue regeneration and repair, but how it is precisely controlled and coordinated with cell proliferation is unclear. Here, we report that Ovol2, a transcriptional repressor that inhibits epithelial-to-mesenchymal transition (EMT), plays a crucial role in adult skin epithelial regeneration and repair. Ovol2-deficient mice show compromised wound healing characterized by aberrant epidermal cell migration and proliferation, as well as delayed anagen progression characterized by defects in hair follicle matrix cell proliferation and subsequent differentiation. Epidermal keratinocytes and bulge hair follicle stem cells (Bu-HFSCs) lacking Ovol2 fail to expand in culture and display molecular alterations consistent with enhanced EMT and reduced proliferation. Live imaging of wound explants and Bu-HFSCs reveals increased migration speed but reduced directionality, and post-mitotic cell cycle arrest. Remarkably, simultaneous deletion of Zeb1 encoding an EMT-promoting factor restores directional migration to Ovol2-deficient Bu-HFSCs. Taken together, our findings highlight the important function of an Ovol2-Zeb1 EMT-regulatory circuit in controlling the directional migration of epithelial stem and progenitor cells to facilitate adult skin epithelial regeneration and repair.

    View details for DOI 10.15252/embr.201846273

    View details for Web of Science ID 000459024800003

    View details for PubMedID 30413481

    View details for PubMedCentralID PMC6322385

  • Epithelial-to-mesenchymal transition in cutaneous wound healing: Where we are and where we are heading DEVELOPMENTAL DYNAMICS Haensel, D., Dai, X. 2018; 247 (3): 473–80


    Cutaneous wound healing occurs in distinct yet overlapping steps with the end goal of reforming a stratified epithelium to restore epidermal barrier function. A key component of this process is re-epithelialization, which involves the proliferation and migration of epidermal keratinocytes surrounding the wound. This spatiotemporally controlled process resembles aspects of the epithelial-to-mesenchymal transition (EMT) process and is thus proposed to involve a partial EMT. Here, we review current literature on the cellular and molecular changes that occur during, and the known or potential regulatory factors of cutaneous wound re-epithelialization and EMT to highlight their similarities and differences. We also discuss possible future directions toward a better understanding of the underlying regulatory mechanisms with implications for developing new therapeutics to improve wound repair in humans. Developmental Dynamics 247:473-480, 2018. © 2017 Wiley Periodicals, Inc.

    View details for DOI 10.1002/dvdy.24561

    View details for Web of Science ID 000425141200013

    View details for PubMedID 28795450

    View details for PubMedCentralID PMC5809211

  • Multiscale modeling of layer formation in epidermis PLOS COMPUTATIONAL BIOLOGY Du, H., Wang, Y., Haensel, D., Lee, B., Dai, X., Nie, Q. 2018; 14 (2): e1006006


    The mammalian skin epidermis is a stratified epithelium composed of multiple layers of epithelial cells that exist in appropriate sizes and proportions, and with distinct boundaries separating each other. How the epidermis develops from a single layer of committed precursor cells to form a complex multilayered structure of multiple cell types remains elusive. Here, we construct stochastic, three-dimensional, and multiscale models consisting of a lineage of multiple cell types to study the control of epidermal development. Symmetric and asymmetric cell divisions, stochastic cell fate transitions within the lineage, extracellular morphogens, cell-to-cell adhesion forces, and cell signaling are included in model. A GPU algorithm was developed and implemented to accelerate the simulations. These simulations show that a balance between cell proliferation and differentiation during lineage progression is crucial for the development and maintenance of the epidermal tissue. We also find that selective intercellular adhesion is critical to sharpening the boundary between layers and to the formation of a highly ordered structure. The long-range action of a morphogen provides additional feedback regulations, enhancing the robustness of overall layer formation. Our model is built upon previous experimental findings revealing the role of Ovol transcription factors in regulating epidermal development. Direct comparisons of experimental and simulation perturbations show remarkable consistency. Taken together, our results highlight the major determinants of a well-stratified epidermis: balanced proliferation and differentiation, and a combination of both short- (symmetric/asymmetric division and selective cell adhesion) and long-range (morphogen) regulations. These underlying principles have broad implications for other developmental or regenerative processes leading to the formation of multilayered tissue structures, as well as for pathological processes such as epidermal wound healing.

    View details for DOI 10.1371/journal.pcbi.1006006

    View details for Web of Science ID 000427427300039

    View details for PubMedID 29481568

    View details for PubMedCentralID PMC5843350

  • Overexpression of Transcription Factor Ovol2 in Epidermal Progenitor Cells Results in Skin Blistering JOURNAL OF INVESTIGATIVE DERMATOLOGY Lee, B., Watanabe, K., Haensel, D., Sui, J. Y., Dai, X. 2017; 137 (8): 1805–8

    View details for DOI 10.1016/j.jid.2017.02.985

    View details for Web of Science ID 000405871600036

    View details for PubMedID 28457910