Trichohyalin expression in skin tumors: retrieval of trichohyalin antigenicity in tissues by microwave irradiation.
BACKGROUND
The antitrichohyalin antibody AE 15 is effective for identifying the cell lineage that undergoes the pathway of inner root sheath-type differentiation. Unfortunately, the AE 15 does not react with trichohyalin in tissue that is formalin-fixed and embedded in paraffin according to routine procedures.


METHODS
We attempted to retrieve the trichohyalin antigenicity in formalin-fixed, paraffin-embedded biopsy specimens that included normal skin as well as skin tumors such as trichofolliculoma and pilotricoma.


RESULTS
We found that the use of a metal solution in combination with microwave oven heating improves the trichohyalin immunoreactivity substantially. Further, trichohyalin was found to be expressed not only in the secondary hair structure in trichofolliculoma but also in a certain cell lineage that differentiates to squamoid cells in pilomatricoma.


CONCLUSIONS
Our findings established that surgical specimens processed under routine procedures can be successfully investigated with AE 15 using the microwave irradiation method. Studies of epidermal diseases expressing trichohyalin should provide valuable insights into our understanding the functional significance of trichohyalin during abnormal keratinization.
Manabe
M
M
Department of Dermatology, Juntendo University School of Medicine, Tokyo, Japan.
Yaguchi
H
H
Iqbal Butt
K
K
O'Guin
W M
WM
Loomis
C A
CA
Sung
T T
TT
Ogawa
H
H
D000276:Adjuvants, Immunologic; D019070:Cell Lineage; D004817:Epidermis / Q000378:metabolism / Q000473:pathology; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D000939:Epitopes / Q000032:analysis* / Q000235:genetics; D005404:Fixatives; D005557:Formaldehyde; D015972:Gene Expression Regulation, Neoplastic; D018859:Hair Follicle / Q000378:metabolism / Q000473:pathology; D006358:Hot Temperature; D006801:Humans; D007381:Intermediate Filament Proteins; D007633:Keratins / Q000378:metabolism; D008872:Microwaves; D018295:Neoplasms, Basal Cell / Q000235:genetics / Q000473:pathology; D016612:Paraffin Embedding; D018296:Pilomatrixoma / Q000235:genetics / Q000473:pathology; D011498:Protein Precursors / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012878:Skin Neoplasms / Q000235:genetics / Q000473:pathology*; D013431:Sulfates; D016707:Tissue Fixation; D017967:Zinc Compounds; D019287:Zinc Sulfate
D000276:Adjuvants, Immunologic; D000939:Epitopes; D005404:Fixatives; D007381:Intermediate Filament Proteins; D011498:Protein Precursors; D013431:Sulfates; D017967:Zinc Compounds; C016159:trichohyalin; D005557:Formaldehyde; D007633:Keratins; D019287:Zinc Sulfate