Patients and samples
PB samples of primary NSCLC patients (Adenocarcinoma, n=27; Squamous
cell lung cancer, n=23) and healthy donors (n=50) were obtained from
Nanjing Drum Tower Hospital from April 2018 to December 2019. Cancer
cases were confirmed by pathological diagnosis. According to the results
of surgery, cancer staging was determined according to the 6th edition
of the American Joint Cancer Commission’s tumor-node-metastasis (TNM)
staging system. All NSCLC patients were diagnosed for the first time and
had not received any treatment before. Detailed information of NSCLC
patients were listed in Table 1. Collected samples were firstly
subjected to centrifuge at 20ºC, 2000 rpm for 5 min to separate the
cells from plasma. ACK buffer was used to lyse red blood cells (RBCs),
and the remaining cells were used for following experiments. To confirm
the potential application of PMN-MDSC frequency in NSCLC diagnosis, we
also collected paired PB samples from NSCLC patients at 3 months after
surgical resection. Meanwhile, PB samples of NSCLC patients with or
without recurrence after surgery were collected to identify the
association of PMN-MDSC proportion with NSCLC recurrence (n=50). All
samples were obtained in accordance with the approval of the Ethics
Committee of Nanjing Drum Tower Hospital. All experiments were
undertaken with the understanding and written consent of each subject.