Androgen receptor (CAG)n polymorphisms and breast cancer risk in a Han Chinese population

Abstract

ABSTRACT. The androgen receptor (AR) is involved in the differentiation and growth of breast cancer. Genetic markers in the AR gene have a plausible role in modulating the risk of breast cancer. In this study, we studied the association of breast cancer and the trinucleotide repeat polymorphism (CAG)n in exon 1 of the AR gene in 202 patients with breast cancer and 183 healthy controls from our hospital (Yinchuan, China). Repeat lengths were determined by fluorescent DNA fragment analysis using the ABI GeneScan software and DNA sequencing. We detected 17 short tandem repeat alleles in exon 1 in the Han population of Ningxia Province, China. The CAG repeat number ranged from 14 to 31 and the frequency ranged from 0.339 to 24.460%. Generally, (CAG) n repeat lengths <22 were classified as short (S), and those >22 were classified as long (L). No association was found between breast cancer and the S/L (CAG) variants. However, the frequency of the (CAG)25 repeats in the breast cancer group was significantly higher than that 10259 Androgen receptor CAG repeat polymorphisms and breast cancer ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 10258-10266 (2015) in the control group (P = 0.033, odds ratio = 1.790, 95% confidence interval = 1.044-3.069). These findings indicate a role for AR gene (CAG)n variations in breast cancer and might be informative for future genetic or biological studies on breast cancer, although these findings need replication in other populations.

Androgen receptor gene CAG repeat polymorphism and ovarian cancer risk: A meta-analysis

“…The abnormal range of CAG repeat length is usually associated with the risk of developing different cancer types including ovarian cancer (7)(8)(9)(10)(11). However, previous studies of the association between AR CAG repeat polymorphism and ovarian cancer risk have shown inconsistent results (10)(11)(12)(13)(14)(15)(16)(17).…”

“…It is reported that different ethnicities have different CAG repeat lengths, with the shortest being reported in African-Americans (mean,20; range, [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] and the longest in Mexican-Americans (mean,25; range, [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] (6). Studies have shown that CAG repeat lengths were associated with the risks of different cancer types in various populations, such as breast cancer, prostate cancer and colorectal cancer (7)(8)(9). In terms of ovarian cancer, some studies have shown that long CAG repeat allele was associated with increased ovarian cancer risk (10,11), while other studies have reported an inverse association between CAG repeat length and ovarian cancer risk (12,13).…”

“…Mapped to X chromosome (q11. [2][3][4][5][6][7][8][9][10][11][12], the AR gene includes eight exons. In exon 1 is a trinucleotide cytosine, adenine, guanine (CAG) repeat, which encodes a polyglutamine tract with varying lengths (5).…”

Mitochondrial determinants of cancer health disparities

“…For Asian women, there is a link between shorter CAG repeats and a higher risk of developing epithelial ovarian cancer [254]. In contrast, longer CAG repeats are present at a higher frequency in breast cancer patients of the Han Chinese population [82]. Although the CAG repeat length does not affect prostate cancer risk amongst European men, carriers of the SNP rs1204038A allele are more likely to develop this cancer [21].…”

Polymorphic CAG Repeat Numbers in the Androgen Receptor Gene of Female Pattern Hair Loss in a Han Chinese Population

“…As a result, studies on the polymorphism of CAG repeat numbers on the AR gene have attracted wide research interest recently. The correlations between the repeat numbers and several diseases such as MAGA, acne, prostate cancer, hypertrichosis, and breast cancer have been established [12,13,14,15,16,17,18]. Thus, we sought to investigate the correlation between the CAG repeat numbers on the AR gene and FPHL in a Han Chinese population.…”