Lumican, a member of the
small leucine-rich proteoglycan family, regulates the assembly and diameter of
collagen fibers in the extracellular matrix of various tissues.
Lumican expression correlates with pathological conditions, including skin fragility, corneal opacification, and corneal and cardiac wound healing.
Lumican is overexpressed in
tumor cells, including in the breast, colorectal, neuroendocrine cell, uterine cervical, and
pancreatic cancers.
Lumican expression also correlates with the growth and
metastasis of various
malignancies. For example,
lumican expression is lower in the dermis of
malignant melanoma cases than in early-stage
melanomas. However, the expression patterns and roles of
lumican in nonmelanoma
skin cancer have not been elucidated. In this study, we used immunohistochemistry and in situ hybridization to examine the expression patterns of
lumican in normal skin,
Bowen disease, and
actinic keratosis. In normal skin,
lumican was expressed in the
collagen fibers in the dermis, acrosyringium, follicular epithelium, and sebocytes but not in epidermal keratinocytes. In
Bowen disease,
lumican was expressed in 34 (91.8%) of 37 patients. Notably, all cases of
actinic keratosis were negative for
lumican. These findings suggest that
lumican plays an important role in the pathogenesis of
Bowen disease and
actinic keratosis and might be useful as an adjunct to the diagnosis for subtypes of 2 diseases: bowenoid
actinic keratosis and
Bowen disease in sun-exposed areas.