Comprehensive Analysis of ERK1/2 Substrates for Potential Combination Immunotherapies

Recent clinical and therapeutic success with RAF and MEK1/2 inhibitors has revolutionized the existing treatment schemes for previously incurable cancers like melanomas. However, the overall therapeutic efficacies are still largely compromised by the dose-limiting side effects and emerging drug resistance mechanisms. Accumulating evidence has revealed the intricate nature of the RAS-RAF-MEK1/2-ERK1/2 pathway, such as activation mechanisms, kinase–substrate relationships, crosstalk with parallel signaling pathways, feedback regulations, and intimate interplay with immune responses. Limited strategies are currently available to exploit the benefits of combining RAF-MEK1/2-ERK1/2 pathway inhibitors with other targeted therapies or immunotherapies. Here, we compiled the kinase–substrate relationships and analyzed the intricate signaling networks of the renowned pathway, providing an integrated and simplified visualization, to reveal the potentials of RAS-RAF-MEK1/2-ERK1/2-based combination therapies.