Towards Universal Screening for Colon Cancer: A Cheap, Reliable, Noninvasive Test Using Gene Expression Analysis of Rectal Swabs

Table 2

Multivariate analysis of gene expression in normal-appearing colon mucosa of 23 week old APC^min mice, as compared to colon mucosa of normal mice.

Colon segment
Gene	1	2	3	4	5	6
COX-2	++	++++	+	++++	+	+++
CXCR-2	+	++	—	++	+	++++
MIP-2	++	++	—	++	+	+++
Gro-α	—	+	—	—	+	+++
OPN	—	—	—	—	—	—

Colons were removed from animals and any polyps removed. The colons were then divided into 6 segments, colon mucosa isolated, and gene expression determined as described in the Material and Methods section, with values for APC^min mice compared to those for wildtype mice. Multivariate analysis was performed on these values as described in the Material and Methods section, in which the significance of the difference in expression between APC^min and wildtype mice was determined for each gene in the presence of all the other genes. For this analysis, 6 mice were used for each group (APC^min and wildtype), and 1 mucosa sample analyzed per segment per mouse, +: 𝑃<0.05; ++: 𝑃<0.01; +++: 𝑃<0.001; ++++: 𝑃<0.0001.