Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 28, 2015; 21(8): 2405-2412
Published online Feb 28, 2015. doi: 10.3748/wjg.v21.i8.2405
Expression profile of polyunsaturated fatty acids in colorectal cancer
Kai Yang, Hong Li, Jin Dong, Yan Dong, Chang-Zheng Wang
Kai Yang, Department of General Surgery, Shijingshan Teaching Hospital of Capital Medical University, Beijing Shijingshan Hospital, Beijing 100043, China
Hong Li, Health Management Institute, Chinese PLA General Hospital, Beijing 100853, China
Jin Dong, Department of Clinical Biochemistry, Chinese PLA General Hospital, Beijing 100853, China
Yan Dong, Institute of Basic Medicine Science, Chinese PLA General Hospital, Beijing 100853, China
Chang-Zheng Wang, Department of Gastroenterology, Southern Building, Chinese PLA General Hospital, Beijing 100853, China
Author contributions: Yang K and Li H contributed equally to this work; Li H, Yang K and Dong J designed the research; Yang K, Dong J and Dong Y performed the research; Dong J, Dong Y and Wang CZ contributed new reagents and analytic tools; Yang K and Li H analyzed the data and wrote the paper.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Hong Li, MD, Health Management Institute, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing 100853, China. lihongam@hotmail.com
Telephone: +86-10-66935134 Fax: +86-10-66935134
Received: August 9, 2014
Peer-review started: August 11, 2014
First decision: August 27, 2014
Revised: September 18, 2014
Accepted: October 15, 2014
Article in press: October 15, 2014
Published online: February 28, 2015
Abstract

AIM: To investigate the relationship between the metabolism of polyunsaturated fatty acids (PUFAs) and tumor-associated factors for predicting the outcome of colorectal carcinoma (CRC) in Chinese patients.

METHODS: Fresh-frozen malignant and normal tissues from 82 Chinese patients with CRC were analyzed for PUFA composition using gas-liquid chromatography. The levels of vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), prostaglandin E2 and platelet-derived growth factor (PDGF) were measured by enzyme-linked immunosorbent assay, and the levels of VEGF, p53 and Ki-67 were measured by immunohistochemistry.

RESULTS: In malignant tissue, compared with normal tissue, the levels of total ω-6 PUFAs (24.64% ± 3.41% vs 26.77% ± 3.37%, P = 0.00) and linoleic acid (LA) (15.46% ± 3.51% vs 18.30% ± 2.83%, P < 0.01) were lower, whereas the levels of total ω-3 PUFAs (1.58% ± 0.74% vs 1.35% ± 0.60%, P < 0.01) and dihomo-gamma-linolenic acid (DGLA) (1.32% ± 0.69% vs 0.85% ± 0.29%, P < 0.01) were significantly higher. The ratios of arachidonic acid (AA)/LA (0.53 ± 0.22 vs 0.42 ± 0.19, P < 0.01) and AA/total ω-6 PUFAs (0.31 ± 0.09 vs 0.27 ± 0.10, P < 0.01) were also significantly higher in malignant tissue. The levels of PDGF (353.10 ± 148.85 pg/mL vs 286.09 ± 104.91 pg/mL, P < 0.01), COX-2 (125.21 ± 70.29 ng/mL vs 67.06 ± 42.22 ng/mL, P < 0.01) and VEGF (357.11 ± 128.76 pg/mL vs 211.38 ± 99.47 pg/mL, P < 0.01) were also higher in malignant tissue compared to normal tissue. COX-2 was inversely correlated with LA (R = -0.3244, P < 0.05) and positively correlated with AA/total ω-6 PUFAs (R = 0.3083, P < 0.05) and AA/LA (R = 0.3001, P < 0.05). The tissue level of LA was highest in poorly differentiated tumors (19.9% ± 6.3%, P < 0.05), while the ratio of AA/ω-3 PUFAs was lowest in these tumors (10.8 ± 2.6, P < 0.05). In VEGF-positive tumors, the level of LA was higher (16.2% ± 3.7% vs 13.9% ± 2.7%, P < 0.01), while the AA/ω-3PUFA, AA/ω-6 PUFA, and AA/LA ratios were lower than in VEGF-negative tumors (5.0 ± 1.8 vs 6.7 ± 3.3, 0.30 ± 0.09 vs 0.34 ± 0.09, 0.50 ± 0.21 vs 0.61 ± 0.21, P < 0.01).

CONCLUSION: The metabolism of PUFAs may play an important role in the evolution of inflammation-driven tumorigenesis in CRC and may be considered a potential marker for prognosis.

Keywords: Fatty acids, Unsaturated, Clinicopathologic, Colorectal neoplasms, Carcinogenesis

Core tip: Colorectal cancer (CRC) is the third most lethal malignancy worldwide. Both ω-3 and ω-6 polyunsaturated fatty acids (PUFAs) are important constituents of cell membranes. In this study, we investigated the relationship between the metabolism of PUFAs and tumor-associated factors for predicting the outcome of CRC in Chinese patients. The identification of modifiable risk factors for CRC is needed to develop interventions and to expand our understanding of this disease. This research shows that the metabolism of PUFAs may play an important role in the evolution of inflammation-driven tumorigenesis in CRC.