Principal Investigator

Isaac Brownell, M.D., Ph.D.

A board-certified dermatologist, Dr. Isaac Brownell is an attending physician on the NIH Clinical Center’s Dermatology Consultation Service and co-directs the Cutaneous Oncology Program at the Walter Reed National Military Medical Center. 

The Cutaneous Development and Carcinogenesis Section studies the signaling pathways such as Hedgehog signaling that regulate the development and maintenance of normal skin, and the changes in these signals that occur during the formation of skin cancer. Our investigations include studying the specification and maintenance of cell lineages in the skin, as well as studying the regulation of stem cells in the skin, and using mouse genetics to model carcinogenesis in the skin.

A current focus in the lab is investigating the the neuro-cutaneous interface and the regulation of neuroendocrine cells (Merkel cells) in the skin. We are also analyzing Merkel cell carcinomas, and are developing pre-clinical mouse models for this uncommon but aggressive skin cancer.

Ongoing Clinical Trials

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Scientific Publications



Hedgehog Signaling Inhibitors Fail to Reduce Merkel Cell Carcinoma Viability.

Carroll TM, Williams JS, Daily K, Rogers T, Gelb T, Coxon A, Wang SQ, Crago AM, Busam KJ, Brownell I
The Journal of investigative dermatology.
2017 May;
doi: 10.1016/j.jid.2017.01.008
PMID: 28130073

Avelumab in patients with chemotherapy-refractory metastatic Merkel cell carcinoma: a multicentre, single-group, open-label, phase 2 trial.

Kaufman HL, Russell J, Hamid O, Bhatia S, Terheyden P, D'Angelo SP, Shih KC, Lebbé C, Linette GP, Milella M, Brownell I, Lewis KD, Lorch JH, Chin K, Mahnke L, von Heydebreck A, Cuillerot JM, Nghiem P
The Lancet. Oncology.
2016 Oct;
doi: 10.1016/S1470-2045(16)30364-3
PMID: 27592805

A Cascade of Wnt, Eda, and Shh Signaling Is Essential for Touch Dome Merkel Cell Development.

Xiao Y, Thoresen DT, Miao L, Williams JS, Wang C, Atit RP, Wong SY, Brownell I
PLoS genetics.
2016 Jul;
doi: 10.1371/journal.pgen.1006150
PMID: 27414798

Evaluating blood levels of neuron specific enolase, chromogranin A, and circulating tumor cells as Merkel cell carcinoma biomarkers.

Gaiser MR, Daily K, Hoffmann J, Brune M, Enk A, Brownell I
2015 Sep 22;
doi: 10.18632/oncotarget.4500
PMID: 26299616

Neural Hedgehog signaling maintains stem cell renewal in the sensory touch dome epithelium.

Xiao Y, Thoresen DT, Williams JS, Wang C, Perna J, Petrova R, Brownell I
Proceedings of the National Academy of Sciences of the United States of America.
2015 Jun 9;
doi: 10.1073/pnas.1504177112
PMID: 26015562

Nerve-derived sonic hedgehog defines a niche for hair follicle stem cells capable of becoming epidermal stem cells.

Brownell I, Guevara E, Bai CB, Loomis CA, Joyner AL
Cell stem cell.
2011 May 6;
doi: 10.1016/j.stem.2011.02.021
PMID: 21549329

Latest News

Spotlight on Research | November 5, 2018

Researchers unearth community of viruses on skin of people with rare disease

NIH researchers studied microbial populations in skin samples from 27 adults and children with a rare immune disorder, DOCK8 deficiency.
Last Updated: May 2020