CD97 expression is associated with poor overall survival in acute myeloid leukemia.

CD97, a member of the adhesion G-protein coupled receptor family, is normally expressed on leukocytes and smooth muscles. CD97 is also expressed in a variety of solid cancers, particularly those with aggressive metastatic phenotypes. Here we characterize the clinical significance of CD97 in acute myeloid leukemia (AML). We analyzed 173 patients from the TCGA AML data set and found that CD97 was higher in cytogenetically normal patients compared with cytogenetically abnormal patients (p = 0.023). High CD97 was also associated with NPM1 mutations (p = 0.0033). Patients with high CD97 expression had shorter overall (median: 7.35 months vs. 24.1 months, p = 0.0015) and disease-free (median DFS: 8.2 months vs. 18.2 months, p = 0.017) survival. Importantly, we identified pathways involved in the leukemia stem cell interaction with the bone marrow niche, such as integrin, CXCR4, and interleukin-8, among the most upregulated signaling pathways in patients with high CD97 expression. Our results suggest that high CD97 expression is associated with poor clinical outcome and indicate a need for future functional and mechanistic studies to investigate the role of CD97 in AML.