Functional promoter -765 G > C variant in COX-2 gene is associated with the susceptibility of breast cancer in Chinese Han women.
BACKGROUND
Cyclooxygenase (COX) is a rate-limiting enzyme in prostaglandins synthesis which exists in two isoforms, COX-1 and COX-2. Over-expression of COX-2 was considered to increase the proliferation and enhance the invasiveness of breast cancer cells. It was suggested that genetic variations in COX-2 could influence its expression. Herein, the present study was aimed to investigate the associations between two mostly studied functional polymorphisms (-765 G > C and 8473 C > T) in COX-2 and breast cancer risk in Chinese Han women.


METHODS
In the hospital-based case-control study, 465 breast cancer patients and 799 cancer-free controls were genotyped for the COX-2 -765 G > C and 8473 C > T polymorphisms using TaqMan assay. We estimated odds ratios (ORs) and 95% confidence intervals (95% CIs) using the logistic regression.


RESULTS
Compared with the wild genotype of -765 G > C, we found a statistically significant increased risk of breast cancer associated with the variant genotypes [GC/CC vs. GG: OR = 1.56, 95% CI = 1.11-2.21]. In the stratified analysis, the increased risk was more predominant among the subgroups of younger subjects (OR = 1.61, 95% CI = 1.00-2.61). Furthermore, the variant genotypes were associated with large tumor size (OR = 3.01, 95% CI = 1.47-6.12). No significant association was observed for the 8473 C > T polymorphism.


CONCLUSIONS
Our results suggest that the functional -765 G > C polymorphism in the promoter of COX-2 may influence the susceptibility and progression of breast cancer in the Chinese Han population.
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.|Department of Nephrology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Jie
J
Gao
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Hua-Feng
HF
Kang
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Xiao-Bin
XB
Ma
School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710061, Shaanxi Province, China.
Wei
W
Tang
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Di
D
Liu
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Yang
Y
Zhao
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Shu-Qun
SQ
Zhang
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Hai-Tao
HT
Guan
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Shuai
S
Lin
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Hong-Tao
HT
Ren
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Xi-Jing
XJ
Wang
Department of Oncology, the Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China.
Zhi-Jun
ZJ
Dai
Breast cancer; COX-2; Cyclooxygenase; Polymorphism; Susceptibility