Expression of alpha-crystallins in human sebaceous carcinoma of the eyelid.
OBJECTIVE
Crystallins are molecular chaperones that protect various cells from apoptosis. This study used immunohistochemistry to examine the expression of alphaA-crystallin and alphaB-crystallin in human sebaceous carcinoma tissues.


METHODS
Nine patients with sebaceous carcinoma of the eyelid underwent excision of the eyelid or orbital exenteration. Formalin-fixed, paraffin-embedded tissue sections were submitted for hematoxylin-eosin staining and immunohistochemistry with anti-alphaA- and alphaB-crystallin antibodies.


RESULTS
In the noncancerous eyelid, crystallins were weakly and homogeneously expressed in the Meibomian gland lobules. In eyelids with sebaceous carcinoma, alphaA-crystallin and alphaB-crystallin were highly expressed in 4 cases, where the cytoplasmic immunoreactivity was heterogeneously detected in the tumor cells. Three and 2 cases were shown to express low levels of alphaA-crystallin and alphaB-crystallin, respectively. A statistically significant correlation was observed between expression levels of alphaA-crystallin and alphaB-crystallin in sebaceous carcinomas (p=0.012). All sebaceous carcinoma tissues contained mitotic tumor cells, which showed predominantly perinuclear immunoreactivity of alphaB-crystallin. The mitotic rate of tumor cells was 5.85+/-1.76 and 10.72+/-1.64 in high and moderate/low alphaB-crystallin-expressing cases, respectively. The number of mitotic cells was significantly higher in moderate/low alphaB-crystallin-positive than in high-positive cases (p<0.01).


CONCLUSIONS
Crystallins are expressed in human sebaceous carcinomas including mitotic cells. Expression of alphaB-crystallin correlated with low number of mitotic tumor cells, suggesting that alphaB-crystallin may play a potential role in the regulation of tumor cell proliferation.
Rigas
Panayota K
PK
Doheny Eye Institute, Los Angeles, California 90033, USA.
Kase
Satoru
S
Rao
Narsing A
NA
D018266:Adenocarcinoma, Sebaceous / Q000378:metabolism* / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D005142:Eyelid Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008297:Male; D008875:Middle Aged; D012626:Sebaceous Gland Neoplasms / Q000378:metabolism* / Q000473:pathology; D038202:alpha-Crystallin A Chain / Q000378:metabolism*; D038203:alpha-Crystallin B Chain / Q000378:metabolism*
D038202:alpha-Crystallin A Chain; D038203:alpha-Crystallin B Chain