Expression of 5-lipoxygenase in human colorectal cancer.
OBJECTIVE
To evaluate the 5-lipoxygenases (Loxs) expression level in human colorectal cancer specimens in order to determine its clinicopathologic significance in human tumorigenesis.


METHODS
The relative quantity of 5-Lox mRNA in paired 91 colorectal tumor and adjacent normal mucosa samples was determined by real time quantitative PCR. Additionally, the expression of 5-Lox and cyclooxygenase (Cox)-2 proteins was also examined using immunohistochemical staining methods.


RESULTS
There was a marked increase in 5-Lox mRNA levels in the tumor compared with paired normal mucosa samples (P < 0.0001). Sixty six (72.5%) tumors showed high 5-Lox mRNA levels. The positivity rate of 5-Lox and Cox-2 protein expression was 68.7% and 79.1% respectively. There was a significant association between tumoral 5-Lox mRNA level and tumor size (Rho = 0.392, P = 0.0002), depth or vessel invasion.


CONCLUSIONS
These results suggest that 5-Lox is up-regulated in colorectal cancer and that inhibition of its expression might be valuable in the prevention and treatment of colorectal cancer.
Soumaoro
Labile Togba
LT
Department of Surgical Oncology, Graduate School, Tokyo Medical and Dental University, Tokyo 113-8519, Japan. soumaorol@yahoo.com
Iida
Satoru
S
Uetake
Hiroyuki
H
Ishiguro
Megumi
M
Takagi
Yoko
Y
Higuchi
Tetsuro
T
Yasuno
Masamichi
M
Enomoto
Masayuki
M
Sugihara
Kenichi
K
D000368:Aged; D001094:Arachidonate 5-Lipoxygenase / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology / Q000473:pathology; D016859:Lipoxygenase Inhibitors; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
D016859:Lipoxygenase Inhibitors; D008565:Membrane Proteins; D012333:RNA, Messenger; D001094:Arachidonate 5-Lipoxygenase; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human