We have reported that a hyperlipidemic state is characteristic of Apc-deficient Min mice with multiple
intestinal polyps. In our earlier case-control study,
colorectal cancer risk showed positive relationships with erythrocyte membrane compositions of palmitic and
oleic acids, but negative links with linoleic and
arachidonic acids. To examine the roles of
fatty acids in
intestinal polyp formation, levels in plasma, erythrocytes, and
intestinal polyps in Min mice were compared with those in wild-type mice. A diet free of eicosapentaenoic and
docosahexaenoic acids with
antineoplastic effects was fed to all mice from 6 to 15 weeks of age.
Fatty acid levels were measured using accelerated
solvent extraction and gas-liquid chromatography. Min mice with a hyperlipidemic state and multiple
intestinal polyps had elevated values for palmitic and
oleic acids in plasma and erythrocytes (at least P < 0.05), and higher plasma level of
linoleic acid (P < 0.05).
Arachidonic acid was 24.5% lower in erythrocytes (P < 0.0005), but did not differ in plasma. In Min mice, moreover, oleic and
arachidonic acids were 1.78 and 1.43 times higher, respectively, in
intestinal polyps than in paired normal mucosa (P < 0.05 and P < 0.01, respectively), but
linoleic acid was 31.9% lower (P < 0.001). The present study suggests that palmitic, oleic, and
arachidonic acids play key roles in
intestinal polyp formation, and demonstrates reduced erythrocyte
arachidonic acid values of Min mice, in line with our previous findings for patients with sporadic
colorectal cancers.