TABLE 1.
Effect of p53 and genetic background on the development of neoplasms in ApcMin/+ mice
| Extracolonic tumors
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|
| Intestinal tumor counta, mean ± SD (no. of mice)
|
Desmoid fibroma count, mean ± SD (no. of mice)
|
Pancreatic tumors, tumor bearing/totalb
|
|||||||
| B6 | 129 | F1 | B6 | 129 | F1 | B6 | 129 | F1 | |
| Genotype | Mom1R/Rc | Mom1S/S | Mom1R/S | Mom1R/R | Mom1S/S | Mom1R/S | Mom1S/S | Mom1S/S | Mom1R/S |
| ApcMin/+p53+/+ | 27 ± 13 (13) | 50 ± 50 (36) | 62 ± 30 (27) | 0 (8) | 1 ± 2 (29) | 3 ± 6 (19) | 0/6 | 0/8 | 1/14 |
| ApcMin/+p53+/BCM | 40 ± 19 (28) | 47 ± 26 (31) | 84 ± 36 (77) | 1 ± 2 (20) | 2 ± 4 (24) | 6 ± 5 (67) | 0/13 | 0/2 | 0/49 |
| ApcMin/+p53BCM/BCM | 75 ± 25 (22) | 46 ± 29 (10) | 103 ± 36 (20) | 33 ± 8 (22) | 22 ± 4 (10) | 28 ± 9 (17) | 0/8c | 9/9 | 8/9 |
| Apc+/+p53BCM/BCM | ND | 0 (5) | 0 (11) | 0 (14) | 0 (5) | 0 (11) | 0/6 | 0/3 | 0/11 |
a
Total tract.
b
Mice were scored as tumor bearing if a tumor was detected during necropsy at 90–100 days of age. Microscopic adenomas in the pancreas of some B6 ApcMin/+ p53tm1TyjJ/tm1TyjJ mice were detected only when the pancreas was sectioned and stained with hematoxylin and eosin.
c
Mom1 is a semidominant modifier of intestinal tumorigenesis that acts independently of p53 (Halberg et al. 2000). Testicular tumors were also observed in mice homozygous for p53BCM/BCM and heterozygous or homozygous for the 129 background, but not depending on Apc deficiency.