Clinical significance of myeloid-derived suppressor cells in breast cancer tissues

Abstract

Objective:To examine the myeloid-derived suppressor cells(MDSCs) in breast cancer tissues and their relationship with clinicopathological characteristics of breast cancer.Methods: Thirty-five breast cancer samples were obtained from Tianjin Cancer Hospital(from Feb.2009 to Dec.2009),and single cell suspensions were prepared.The proportions of MDSCs(Lin-CD33+CD13+CD14-CD15-)in breast cancer tissues were determined by flow cytometry.Immunohistochemistry was used to detect the expressions of ER,PR,Her-2 proteins in the same tumor tissues.Then we analyzed the correlation of MDSCs ratio with clinical characteristics of breast cancer.Results: The MDSCs ratio in breast cancer tissues was correlated with the clinical stage and metastasis lymph node numbers in breast cancer patients,with the ratio in stage Ⅲ breast cancer patients([11.70±7.85]%) being significantly higher than that in stage Ⅰ/Ⅱ patients([5.32±4.59]%).Patients with more than 3 metastasis lymph nodes had a higher MDSCs ratio([10.97±7.87]%) than patients with less than 3 metastasis lymph nodes([5.86±5.26]%,P0.05).MDSCs ratio was not correlated with ages,pathologic types,tumor diameters,histological grades,or expressions of ER,PR and Her-2 of breast cancer patients(P0.05).Conclusion: The MDSCs ratio in breast cancer tissues is correlated with the clinical stage and lymph node metastasis of breast cancer,and the increased MDSCs numbers may be an important reason of immune suppression in breast cancer patients.