Aims: The present study is to determine the expression of aldehyde dehydrogenase 1 (ALDH1) and ATPbinding cassette superfamily G member 2 (ABCG2) in patients with triple-negative breast cancer, and to understand the relationship of ALDH1 and ABCG2 with triple-negative breast cancer.
Methods: A total of 56 patients who received triple-negative breast cancer resection and axillary lymph node dissection at our hospital between August 2013 and June 2016 were included in the present study. Primary focus tissues, tumor-adjacent tissues and lymph node tissues of the patients were collected. According to pathological examinations, 21 patients had lymph node metastasis (metastasis group), and 35 had no lymph node metastasis (non-metastasis group). Tumor-adjacent tissues were used as control group. MDA-MB-231 cells were transfected with small-interfering RNA to inhibit the expression of ALDH1 and ABCG2. Quantitative real-time polymerase chain reaction was used to determine the expression of mRNA, while Western blotting was carried out to measure protein expression. MTT assay was employed to determine the proliferation of MDA-MB-231 cells.
Results: Expression of ALDH1 and ABCG2 mRNA and protein was elevated in breast cancer tissues and metastatic lymph node. Transfection with the siRNA of ALDH1 and ABCG2 reduced the expression of ALDH1 and ABCG2, respectively. Down-regulation of ALDH1 and ABCG2 expression decreased the proliferation of MDA-MB-231 cells.
Conclusion: The present study demonstrates that the expression of ALDH1 and ABCG2 in primary tumor tissues from patients with triple-negative breast cancer is increased than that in tumor-adjacent tissues, and the expression of ALDH1 and ABCG2 in lymph node in patients with lymph node metastasis is higher than that in patients without lymph node metastasis. ALDH1 and ABCG2 may regulate the invasion and lymph node metastasis, or affect the drug resistance of triple-negative breast cancer.