2.1 Chemicals and reagents
Acetonitrile (ACN, MS grade), trifluoroacetic acid (TFA, MS grade), formic acid (FA, MS grade), PierceTM BCA Protein Assay Kit and HeLa Protein Digest Standard were purchased from Thermo Scientific (St. Louis, MO, USA). Culture media such as Dulbecco’s Modified Eagle’s Medium (DMEM), penicillin/streptomycin (P/S), fetal bovine serum (FBS) and trypsin-EDTA were from Gibco Life Technologies (New York, USA). The iST kit for proteomic sample preparation was purchased from PreOmics GmbH (Planegg, Germany). Deionized water used in the experiments was prepared by the Milli-Q50SP system (Millipore, Milford, MA).
2.2. Patients and sample collection
The present study was conducted in accordance with the guidelines of the Declaration of Helsinki with the approval of the Research Ethics Committee from Ruijin Hospital, Shanghai Jiaotong University School of Medicine (1.0/2019-10-1). Written informed consent was obtained from all patients or their legal representatives prior to their participation in the study.
A total of 29 samples from gliomas and BrMs patients were obtained from the Ruijin Hospital, Shanghai Jiao Tong University School of Medicine between October 2020 and September 2021. Details of clinical information on the subjects were shown in Figure 2A and Table S1. Tumor tissues were collected after surgery, and were washed three times with PBS. After that, tissues were immediately transferred to liquid nitrogen and collected into 2 mL cryogenic storage vials (Corning, New York, USA), and stored at −80 °C for later use.