In spite of enhanced understanding on the physiology of circadian rhythm in metabolism homeostasis and colorectal tumorigenesis, habitual sleep duration, an important and potentially modifiable lifestyle factor, in association with CRC has not been examined in population-based studies.
[ 12] Little is know about the relationship between polyamine metabolism and PPARγ expression in colorectal tumours and available information is derived from in vitro studies [ 5, 13].
In this study, we conducted a comprehensive analysis of 159 tagSNPs in 11 genes involved in folate-associated one-carbon metabolism and the risk of distal colorectal adenomas.
Functional analysis showed that the encoding proteins were associated with several canonical pathways (pyrimidine and purine metabolism, colorectal cancer metastasis signalling).
Human liver microsomes and colorectal cancer microsomes were assayed for paclitaxel metabolism as described elsewhere (Harris et al, 1994) except that the incubation volume was reduced to 30 μl, and the amount of microsomal protein was 75 to 150 μg.
Although outside the scope of this study, Beckman et al. (1999) examined the association between genetic variants of iron metabolism (HFE, TF, and the two combined) and risk for multiple myeloma, breast cancer, and colorectal cancer.
In contrast, our findings indicate that local metabolism in colorectal cancer tissue is mainly CYP3A-dependent, and that CYP2C8 metabolism is of secondary importance.
Abnormal BA metabolism has been associated with liver injury, metabolic disorders, cardiovascular diseases and digestive system diseases such as inflammation bowel disease (IBD) and colorectal cancer 18, 19, 20, 21.
The potential mechanisms underlying alcohol's effects include the carcinogenicity of acetaldehyde (for colorectal cancer and upper aero-digestive tract cancers), which is an intermediate product of alcohol metabolism; impairment of the one-carbon nutrient metabolism (for colorectal cancer); alteration of hormone levels (for breast cancer); and oxidative stress resulting from alcohol metabolism.
DNA methylation was not associated with alcohol intake, which is known to have negative effects on methyl metabolism and is associated with increased risk of colorectal cancer (Chen et al, 1996).
