The clinical significance of interleukin-8 gene expression in breast cancer

Objective To investigate the clinical significance of interleukin-8 (IL-8) gene expression in breast cancer. Methods Real-time quantitative reverse transcription polymerase chain reaction (RQ-RT-PCR) method was established for detecting IL-8 mRNA and GAPDH expression levels in 122 cases of breast tumor and the corresponding adjuvant normal breast tissue. Normal IL-8 expression level(IL-8N) was determined as a ratio between IL-8 and GAPDH for each case. The IL-8N of tumor tissue over the normal tissue IL-8N of the same case was calculated as T/N ratio, and T/N value was correlated with the clinical-pathological parameters. Results IL-8N expression levels of the breast cancer tissue were significantly higher than that of the adjuvant normal breast tissue, but there were no statistical differences between IL-8N of the benign breast tumor and the nearing normal tissue. IL-8N and T/N ratio of the malignant cancer tissue were significantly higher than that of benign tumor. Furthermore, T/N ratio were positively correlated with lymph nude metastasis, but negatively correlated with menopause,estrogen receptor and progesterone receptor statuses. Conclusion The IL-8 gene is highly expressed in breast cancer which suggested that IL-8 level assessed by RQ-RT-PCR could be a novel marker of disease progression and poor prognosis.