Stearoyl-CoA desaturase 1 (Scd1) gene overexpression is associated with genetic predisposition to hepatocarcinogenesis in mice and rats

The stearoyl-CoA desaturase 1 (Scd1) gene is involved in
the synthesis and regulation of unsaturated fatty acids. Its
expression is increased by several treatments/conditions
that are associated with hepatocarcinogenesis (peroxisome
proliferators, iron overload, dichloroacetic acid). We found
that the Scd1 gene is differentially expressed, showing
10-fold higher mRNA levels in the normal liver tissue of
C3H/He mice, which are genetically susceptible to hepatocarcinogenesis,
than of BALB/c mice, which are resistant.
Similarly, Scd1 mRNA expression was ~4-fold higher in
the normal liver of F344 rats, which are susceptible to
hepatocarcinogenesis, than in Brown Norway (BN) rats,
which are resistant. The chromosomal location of the Scd1
locus, both in mice and rats, excludes Scd1 candidacy as a
hepatocellular tumor-modifier gene, as the Scd1 locus
did not show allele-specific effects in a BALB/cC3H/He
intercross or in a BNF344 backcross and intercross. No
Scd1 coding polymorphisms were detected in the mouse
and the rat strains showing elevated Scd1 expression. These
results suggest that the Scd1 gene represents a downstream
target of hepatocellular tumor-modifier loci in two rodent
species.