Co-stimulatory and co-inhibitory immune markers in solid tumors with MET alterations

The implication of MET alterations in solid tumors and the immune microenvironment remains elusive. Formalin-fixed, paraffin-embedded samples of 21 patients with solid tumors harboring MET alterations were used for immunohistochemical staining. Extracted RNA was analyzed with the NanoString nCounter human PanCancer immune profiling panel (NanoString Technologies, Inc., WA, USA). Patients were diagnosed with lung (n = 10), breast (n = 5), genitourinary (n = 3) or colorectal cancer (n = 3). Eleven had a MET missense mutation, four had an exon 14 splice site mutation and six had MET amplification. CD6, CCL19, CD40LG, XCR1, MAGEA1, ATM and CCL19 genes were significantly differentially expressed in MET-altered cancers. MET alterations may have a role in various solid tumors as potential therapeutic targets and combination therapy candidates with immune checkpoint inhibitors.