BACKGROUND: Regular use of snuff is known to cause whitish @entity3137 of variable severity at the usual quid placement site. The main aim of this study was to elucidate cellular mechanisms involved in snuff-induced epithelial changes. METHODS: Expression patterns for markers of cell proliferation ( @entity1364 , Ki-67), cell cycle regulation ( @entity876 , @entity3544 ), keratin changes (pankeratin, @entity2873 , @entity4166 ), cell stress ( @entity2285 ) and collagen type IV in 14 snuff-induced @entity3137 and 12 control samples were analyzed by immunohistochemistry (IHC). RESULTS: On light microscopy, all snuff-induced lesions were characterized by a hyperkeratinized and thickened epithelium. Some vacuolized cells, markers of cell degeneration, were frequently seen (in 9/14 of the samples) in the superficial layers in epithelia. Expression of @entity1364 and Ki-67 was found in a statistically significantly fewer cells in snuff-induced lesions (P < 0.001) than in the controls. This indicates that epithelia in snuff-induced lesions are not thickened as a result of increased cellular proliferation, but by protracted turnover of differentiating cells. Of cell cycle markers, @entity3544 was found be up-regulated in 4/14 snuff-induced lesions, probably by @entity876 -independent pathways. Only two snuff-induced lesions showed @entity876 positivity. However, the number of stained cells with @entity876 and @entity3544 was not statistically different from that in controls. Expression of @entity2873 , but not any alterations in @entity4166 expression, was seen in 5 of 14 snuff-induced lesions. Snuff also seems to stimulate the expression of collagen type IV, possibly by basal cells, as indicated by the thickened staining of the basal lamina. CONCLUSIONS: The findings of this study showing suppressed cellular proliferation and infrequent @entity876 dysfunction in snuff lesions may partly explain why @entity6349 changes are seldom seen in @entity3137 induced by the Scandinavian type of snuff.

Proliferation and differentiation markers in snuff-induced XXXX .

@entity1364 :: ('5111', 'Gene') :: ['PCNA'] @entity4166 :: ('3880', 'Gene') :: ['CK19'] @entity2285 :: ('3308', 'Gene') :: ['HSP 70'] @entity6349 :: ('MESH:D004416', 'Disease') :: ['dysplastic'] @entity3544 :: ('644914', 'Gene') :: ['p21'] @entity876 :: ('7157', 'Gene') :: ['p53'] @entity2873 :: ('3875', 'Gene') :: ['CK18'] @entity3137 :: ('MESH:D009059', 'Disease') :: ['oral mucosal lesions', 'mucosal lesions']
@entity3137 :: (MESH:D009059,Disease) :: ['oral mucosal lesions']
