Colonic mucosal fatty acid synthase as an early biomarker for colorectal neoplasia: modulation by obesity and gender.

Abstract

BACKGROUND:

We have previously reported that colonic pericryptal microvascular blood flow is augmented in the premalignant colonic epithelium, highlighting the increased metabolic demand of the proliferative epithelium as a marker of field carcinogenesis. However, its molecular basis is unexplored. In this study, we assessed the expression of a regulator of the "lipogenic switch," fatty acid synthase (FASN), in early colon carcinogenesis for its potential biomarker utility for concurrent neoplasia.

METHODS:

FASN expression (IHC) in the colonic epithelium from azoxymethane and polyposis in rat colon (Pirc) models of colorectal cancer was studied. FASN mRNA expression from endoscopically normal rectal mucosa was evaluated and correlated with colonoscopic findings (pathologic confirmation of neoplasia).

RESULTS:

FASN expression progressively increased from premalignant to malignant stage in the azoxymethane model (1.9- to 2.5-fold; P < 0.0001) and was also higher in the adenomas compared with adjacent uninvolved mucosa (1.8- to 3.4-fold; P < 0.001) in the Pirc model. Furthermore, FASN was significantly overexpressed in rectal biopsies from patients harboring adenomas compared with those with no adenomas. These effects were accentuated in male (∼2-fold) and obese patients (1.4-fold compared with those with body mass index < 30). Overall, the performance of rectal FASN was excellent (AUROC of 0.81).

CONCLUSIONS:

FASN is altered in the premalignant colonic mucosa and may serve as a marker for colonic neoplasia present elsewhere. The enhanced effects in men and obesity may have implications for identifying patient subgroups at risk for early-onset neoplasia.

IMPACT:

These findings support the role of rectal FASN expression as a reliable biomarker of colonic neoplasia.

• Authors: Mart Dela Cruz, Ramesh K Wali, Laura K Bianchi, Andrew J Radosevich, Susan E Crawford, Lisa Jepeal, Michael J Goldberg, Jaclyn Weinstein, Navneet Momi, Priya Roy, Audrey H Calderwood, Vadim Backman, Hemant K Roy
• Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (Cancer Epidemiol Biomarkers Prev) Vol. 23 Issue 11 Pg. 2413-21 (Nov 2014) ISSN: 1538-7755 [Electronic] United States
• PMID: 25155760 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: ©2014 American Association for Cancer Research.

Chemical References

• Biomarkers, Tumor
• Fatty Acid Synthases

Topics

• Animals
• Biomarkers, Tumor
• Colorectal Neoplasms (metabolism, pathology)
• Disease Models, Animal
• Fatty Acid Synthases (metabolism)
• Humans
• Male
• Obesity (complications, pathology)
• Rats