Among negatively charged
lipids,
sulfoglycolipids are known to be expressed by specific cell populations and to be involved in their functions, including in adhesion with functional
proteins, modification of
ion channels and induction of cellular differentiation. Accordingly, we determined their amounts in several histologically defined types of ovarian
carcinoma tissues.
Sulfoglycolipids were determined by TLC-immunostaining with monoclonal anti-
sulfatide antibodies and the gene expression of their synthetic
enzymes was by RT-PCR. All types of ovarian
carcinomas were revealed to exhibit potential to synthesize
sulfoglycolipids, either
sulfatide (I(3)SO3-GalCer) or sulfated
lactosylceramides (II(3)SO3-LacCer), which were expressed at the following frequencies, 6 out of 6
mucinous cystadenocarcinomas, 4 out of 7
serous cystadenocarcinomas, 2 out of 3
endometrioid carcinomas, and 2 out of 3
clear cell adenocarcinomas. All
mucinous cystadenocarcinoma tissues preferentially contained
sulfatide in amounts of 0.61-1.13 μg per mg dry weight, the molecular species being similar with those of GalCer. Whereas the other
carcinomas contained either
sulfatide or sulfated LacCer, the latter being detected in 4 out of 6 specimens with
sulfoglycolipids. The expression of
sulfatide and sulfated LacCer was found to be positively correlated with the amounts of GalCer and LacCer as substrates for
sulfotransferase and expression of the genes for GalCer
sulfotransferase and
ceramide galactosyltransferase.
Sulfoglycolipids in ovarian
carcinoma tissues were revealed to be expressed in morphologically defined type-characteristic manners, in contrast to the ubiquitous distribution of GM3.