Using Flow Cytometry to Study Myc's Role in Shaping the Tumor Immune Microenvironment.

Myc is deregulated in most-if not all-cancers, and it not only promotes tumor progression by inducing cell proliferation but is also responsible for tumor immune evasion. In a nutshell, MYC promotes the development of tumor-associated macrophages, impairs the cellular response to interferons, induces the expression of immunosuppressive molecules, and excludes tumor infiltrating lymphocytes (TILs) from the tumor site. Based on the insights into the role of MYC in promoting and regulating immune evasion by cancer cells, it is of special interest to study the different immune cell populations infiltrating the tumors. MYC inhibition has emerged as a potential new strategy for the treatment of cancer, directly inhibiting tumor progression while also counteracting the immunosuppressive tumor microenvironment, allowing an optimal anti-tumor immune response. Hence, this chapter describes a flow cytometry-based method to study the different immune cell subsets infiltrating the tumor by combining surface, cytoplasmic, and nuclear multicolor protein stainings.