Despite recent advances in targeted and immune-therapies, there is an urgent need for new therapeutic approaches for metastatic non-small cell lung cancer (NSCLC). SH2 domain-containing phosphatase-2 (SHP2), encoded by PTPN11, is a key ?positive? signaling component, required for RAS/ERK MAP kinase activation by receptor tyrosine kinases (RTKs) and cytokine receptors, as well as by oncogenic amplified RTKs and protein-tyrosine kinase (PTK) fusion proteins. Recently, potent, orally available, highly specific SHP2 inhibitors were developed. These agents inhibit amplified RTK/PTK-fusion-driven cells/tumors and are in Phase I clinical trials. Our results suggest that SHP2-inhibitors (SHP2-Is) could have a much broader role in cancer therapy. SHP2-Is block adaptive resistance to MEK inhibitors (MEK-Is) in KRAS-mutant and -WT cells, acting upstream of guanine nucleotide exchange factors (SOS1/2). Consequently, SHP2-Is have single agent efficacy against ?cycling? KRAS mutants (e.g., KRASG12C), which retain intrinsic GTPase activity. Supported by extensive Preliminary Data, we hypothesize that SHP2-Is will also enhance the efficacy of newly developed KRASG12C (G12C) inhibitors in G12C-mutant NSCLC, the effects of MEK-Is in Osimertinib (Osi)-resistant EGFR- mutant NSCLC, and the effects of Osi in Osi-sensitive EGFR-mutant NSCLC. SHP2 also binds immune checkpoint receptors, including PD1, might inhibit immune receptor signaling, and has complex effects on myeloid cells and other cells in the tumor microenvironment (TME). These pleiotropic actions position SHP2 at the nexus of targeted and immune therapies. This MPI application joins experts in SHP2 action (NEEL) and NSCLC translational biology (WONG) to clarify the utility of SHP2-Is as NSCLC therapeutics. We will: (1) test combinations of SHP2-Is with covalent RASG12C inhibitors, MEK-Is, and EGFR-inhibitors in KRAS- and EGFR-mutant NSCLC GEMMs; (2) clarify cell-autonomous and non-autonomous effects of these combinations using state-of-the art immune assays, drug-resistant tumor cells, immune cell depletion and new, inducible SHP2-I-resistant GEMMs; and (3) analyze recurrent tumors and perform CRISPR/Cas9 screens to identify the landscape of resistance to these agents.
NSCLC is the most common and deadly form of cancer in the US and worldwide, and new therapies are urgently needed. Our work will clarify how to optimally deploy SHP2-Is, which recently entered the clinic, in NSCLC, define potential resistance mechanisms, and potentially suggest new combination therapies for this deadly disease.
