Jl. Counts et Ji. Goodman, COMPARATIVE-ANALYSIS OF THE METHYLATION STATUS OF THE 5' FLANKING REGION OF HA-RAS IN B6C3F1, C3H HE AND C57BL/6 MOUSE-LIVER/, Cancer letters, 75(2), 1993, pp. 129-136
We examined the methylation status of the 5' flanking region of Ha-ras
in the liver of the liver tumor-prone B6C3F1 male (C57BL/6 female x C
3H/He male) and C3H/He male, plus the relatively resistant C57BL/6 mal
e mouse strains. Southern analysis revealed the presence of CCGG sites
methylated at the internal cytosine, as well as unmethylated CCGG sit
es in all three strain's. Digestion with StyI and XhoI revealed an unm
ethylated Xhol site in the C57BL/6 male. This pattern is not obvious i
n the B6C3F1 or C3H/He, indicating sequence variation and/or less meth
ylation of Ha-ras in those strains of mice that exhibit a high propens
ity towards development of liver tumors.