METALLOTHIONEIN EXPRESSION IN CARCINOMA OF THE GALLBLADDER

Aims: Metallothioneins (MT) are sulphur-rich, low molecular-weight, in tracellular metal-binding proteins with a possible role in carcinogene sis of some human tumours. Metallothionein expression in gallbladder c ancer has not been studied previously. Methods and results: Immunohist ochemical expression of metallothionein was studied in 42 gallbladders (27 cases of carcinoma of the gallbladder, eight chronic cholecystiti s and seven cases of normal gallbladder). Metallothionein expression w as significantly higher in cases with carcinoma of the gallbladder (70 .37%) as compared to chronic cholecystitis (25%) and normal gallbladde rs (0%). There was a trend suggestive of increasing MT expression with increasing histological dedifferentiation of carcinoma of the gallbla dder. Conclusions: The increased expression of MT in cases of carcinom a of the gallbladder may represent an increased exposure to heavy meta ls, which are known carcinogens, and may have a role in gallbladder ca rcinogenesis. Metallothionein over-expression in carcinoma of the gall bladder may be relevant to the poor prognosis and chemoresistance seen in these cases.