Research / Clinical Summary

Colin Jamora, PhD Assistant Professor, Biological Sciences Cancer Biology Program Contact by Email

Dr. Jamora investigates the mechanisms governing organ formation and regeneration using the mouse skin and hair as a model system. The multipotent cells of the epidermal ectoderm of the developing animal can choose between a number of fates, including the decision to become epidermis or hair follicle.

The general theme of the Jamora lab is to identify the developmental cues that specify the formation of these structures as well as changes in cellular behavior they elicit to transform a homogenous sheet of embryonic cells into a complex organ. The mammalian epidermis is a stratified epithelia of cells undergoing a terminal differentiation program whose outermost layer of crosslinked proteins and lipids form a barrier against external assault while maintaining internal fluids. This differentiation program results in the death of the skin cells (keratinocytes) thus leading to the turnover of the epidermis every couple of weeks.

In order to maintain epidermal homeostasis there is a balance between the self-renewal of epidermal stem cells with those entering the differentiation program to replenish the epidermis. A current focus of the lab is testing the hypothesis that the protein E-cadherin plays a regulatory role over the decision to proliferate or differentiate. E-cadherin is a well-known protein at the cell surface that mediates cell-cell adhesion. However, it is becoming increasingly clear that this protein also plays a role in multiple signal transduction pathways. Which of these E-cadherin dependent pathways regulate epidermal stem cell behavior is an area of active investigation. Our work on hair follicle formation focuses on the cell and developmental biology of bud formation. This hair bud is a cluster of select cells that emanate from the epidermal ectoderm that have adopted the follicular fate. This “budding morphogenesis” is a common theme in the development of a variety of organs including the lungs, liver, and pancreas.

Their current studies are focused on the transcription factors that both specify the hair follicle fate and coordinate changes in cell proliferation, polarity, and the reorganization of the basement membrane to allow the invasion of the hair follicle from the epithelial compartment into the underlying dermis. Interestingly, these are the same processes that take place during the metastasis of carcinomas.

Jamora's studies entail the generation and analysis of transgenic and knockout mouse models to examine the requirement and function of candidate genes in the development of skin and hair. By culturing skin stem cells they perform cell biological and biochemical experiments to elucidate the signaling pathway in which these proteins participate to alter cellular behavior and form these structures from seemingly uniform sheets of epithelial cells.

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