Small molecule SUMO inhibition for biomarker-informed B-cell lymphoma therapy

Aberrant activity of the SUMOylation pathway has been associated with MYC overexpression and poor prognosis in aggressive B-cell lymphoma (BCL) and other malignancies. Recently developed small molecule inhibitors of SUMOylation (SUMOi) target the heterodimeric E1 SUMO activation complex (SAE1/UBA2). Here, we report that activated MYC signaling is an actionable molecular vulnerability in vitro and in a pre-clinical murine in vivo model of MYCdriven BCL. While SUMOi conferred direct effects on MYC-driven lymphoma cells, SUMO inhibition also resulted in substantial remodeling of various subsets of the innate and specific immunity in vivo. Specifically, SUMOi increased the number of memory B-cells as well as cytotoxic and memory T-cells, subsets that are attributed a key role within a coordinated antitumor immune response. In summary, our data constitute pharmacologic SUMOi as a powerful therapy in a subset of B-cell lymphomas causing massive remodeling of the normal B-cell and T-cell compartment.