We designed a 2-stage study to investigate
chemotactic factor receptor 5 (CCR5) gene expression in
breast cancer tissues and axillary lymph nodes and analyze the association between the CCR5-Î"32 gene polymorphism and the clinical features and prognosis of
breast cancer patients. The first stage examined 72 cases of invasive
ductal carcinoma and axillary lymph node tissue, 50 cases of breast
fibroadenoma tissue, and 40 cases of normal breast tissue. The tissues specimens were embedded in
paraffin, and CCR5 expression was detected using immunohistochemical methods. C-erbB-2, p53, Ki-67,
estrogen receptor, and
progesterone receptor expression were also detected in the
breast cancer tissues. The second stage examined 35 cases of surgically removed tissue. Relative expression levels of CCR5
messenger RNA (
mRNA) in primary foci, axillary lymph node, and
cancer-adjacent tissues of the
breast cancer and breast
fibroadenoma samples were detected using real-time quantitative reverse transcription-polymerase chain reaction assay. We found that 1) CCR5
mRNA relative expression levels in
breast cancer tissue were significantly higher than those in adjacent normal tissue (P < 0.01) and benign
tumors (P < 0.05). The relative CCR5
mRNA relative expression level between phase II and phase III
breast cancer tissues was statistically significant (P < 0.05). The CCR5
mRNA relative expression level between adjacent normal tissues and
fibroadenoma tissues was not significantly different (P > 0.05). 2) Relative CCR5
mRNA expression level was significantly higher in metastatic lymph node tissues than that in non-metastatic lymph nodes (P < 0.05), and 3) CCR5 expression in
breast cancer tissue was positively correlated with axillary
lymph node metastasis (chi-square = 4.982, P = 0.026, r = 0.305). CCR5 expression was mildly and positively correlated with the oncogene C-erbB-2 (P < 0.05, r = 0.291). 4) CCR5 expression in
breast cancer tissue was not correlated with age, menopause, maximum
tumor size,
tumor phase, p53, Ki-67,
estrogen receptor,
progesterone receptor, or other clinical features (P > 0.05). We concluded that CCR5 expression significantly increases in
breast cancer tissues and metastatic lymph nodes. CCR5 plays a role in
breast cancer development and axillary
lymph node metastasis. It can be used indirectly as an
indicator of axillary
lymph node metastasis and prognosis.