Background: Lymph nodes (LNs) are among the first sites of tumor metastasis. The expression of chemokines and chemokine receptors in LNs are involved in cancer prognosis and are considered to be good predictors of tumor progression. The main aim of this study was to assess the expression of important, tumor-promoting chemokines and chemokine receptors in LNs of breast cancer patients. LNs were isolated from eighteen women diagnosed with breast cancer. Data were compared between positive and negative LNs. Expression of chemokines and chemokine receptors were determined by quantitative real-time PCR (qRT-PCR) and flow cytometry.
Results: Results of qRT-PCR showed that all chemokines, in particular MCP-1, IL-8, SDF-1 and CXCL13, and chemokine receptors CXCR3, CXCR4 and CCR5 showed greater mRNA expression in LN(+) compared to LN(-) samples. However, these differences were not statistically significant. IL-8 and CXCR5 gene transcripts had significantly higher expression in LN(+ )patients with stage III compared to those with stage II tumors (P value = 0.04). Results of flow cytometry analysis showed a higher, significant presence of CD69(+), CCR5(+) and CD3(+)CCR5(+) cells in LN of LN(+) compared to LN(- )breast cancer patients (P value<0.05). Expression of MCP-1 was higher in LN(+) patients, which was near significance (P value = 0.07).
Conclusions: Our findings provide additional information on the expression of essential chemokines and chemokine receptors in LN and on their relationships to important prognostic factors in breast cancer. These findings have important implications for immunotherapeutic interventions in the treatment of breast cancer.