[1655] Immunophenotypic Characterization of Epithelial-Stromal Interface Cells.

Patrick Adegboyega. LSU Health Sciences Center, Shreveport

Background: In visceral organs, the epithelium and the stroma are separated by a layer of stromal cells and the basement membrane. These epithelial-stromal interface (ESI) cells are known to play significant regulatory roles in the organogenesis, differentiation and homeostasis of the overlying epithelium. In the gastrointestinal tract as well as in other viscera, these cells are also postulated to play critical roles in inflammation, restitution, and regeneration of damaged epithelium and also involved in neoplastic transformation and proliferation of the epithelial cells in the process of carcinogenesis and tumorigenesis respectively. However, the histogenesis and the biology of these cells are yet to be elucidated. Hence this study, to characterize the immunophenotypic features of these cells in skin adnexae and visceral organs.
Design: Benign samples were obtained from resection specimens of the following organs: Skin (n=10), breast (n=10), parotid gland (n=10), pancreas (n=10), prostate (n=10), small bowel (n=10) and colon (n=15). The tissue samples were fixed in formalin solution and paraffin-embedded for routine H&E. Representative sections were immunostained for the followings: 5 cytokeratins that are reportedly expressed in myoepithelial cells (CK5, CK7, CK8, CK14, CK18, CK19 and K903), 6 non-keratin related structure-specific microfilaments and intermediate filaments (alpha smooth muscle [SMA], calponin, desmin, H-caldesmon, smooth muscle myosin heavy chain [SMMHC], and vimentin) and 7 nonstructural proteins (CD10, CD34, CD117, GFAP, maspin, p63, and S100). Immunohistochemistry was done using avidin-biotin detection method with antigen retrieval.
Results: ESIs in both small and large intestinal mucosa expressed smooth muscle–related microfilaments and intermediate filaments ([SMA, calponin, H-caldesmon, SMMHC) and vimentin; but stained negative with desmin, all the cytokeratins and the nonstructural proteins.
Conclusions: ESIs in the small and large bowel have similar immunophenotypic features; but in their lack of expression of the keratins and the non structural proteins studied, are distinctly different from the corresponding (myoepithelial) cells in other glandular organs such as breast, prostate and skin adnexal structures where they have been proposed to be the progenitor cells for the epithelium. Our results also show that the immunophenotypic features and the biology of the interface subepithelial stromal cells appear to vary from organ to organ. Therefore, reports of observations of such cells in one organ may not necessarily be true for the counterpart cells in another organ.
Category: Pathobiology

Wednesday, March 2, 2011 9:30 AM

Poster Session V # 215, Wednesday Morning

 

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