Targeting oncogenic KRAS to sensitize pancreatic cancer to NK cell immunotherapy

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with a 5-year survival rate of 13% that is refractory to immunotherapies. Combination with targeted therapy is a potential approach for overcoming resistance and sensitizing tumors. To this end, recently developed mutant-selective inhibitors targeting oncogenic KRAS, which is mutated in >90% of PDACs, have been shown to remodel the immunosuppressive PDAC tumor microenvironment (TME). This proposal investigates the mechanisms by which KRAS inhibition can promote Natural Killer (NK) cell therapy response in PDAC. NK cells are cytotoxic innate immune cells that play a role in tumor killing. Our transcriptomic analysis of patients with PDAC from The Cancer Genome Atlas revealed that higher expression of NK cell marker, NCAM1 (CD56), is associated with favorable patient survival, indicating that greater NK cell infiltration may indeed promote tumor control. Our preliminary data demonstrate that combining KRAS inhibition with NK cells increases PDAC cell killing in vitro, in part by increasing tumor-cell expression of NK cell activating ligands and altering cytokine/chemokine secretion. In support, using a bioengineered 3-dimensional (3D) collagen matrix platform with quantitative microscopy and migration assays, we find that KRAS inhibition increases NK cell motility and migration towards PDAC cells. To further enhance NK cell homing and tumor killing, we have developed a novel NK cell Tri-specific killer engager (TriKE) targeting B7-H3, an antigen overexpressed on PDAC cells, thereby arming NK cells with tumor-antigen specificity. Our data demonstrate that the B7-H3 TriKE enhances NK cell motility and improves tumor killing, which is further maximized with KRAS inhibition, resulting in complete abrogation of in vivo tumor growth in initial xenogeneic studies. In Aim 1, we seek to further define the signaling mechanisms that regulate NK cells in the context of KRAS inhibition. Specifically, we will determine which KRAS inhibition-induced NK cell ligands and cytokines in tumor cells are responsible for increased NK cell activation, migration and proliferation, and pinpoint the signaling pathways downstream of KRAS in PDAC cells that regulate their expression. We will utilize a combination of in vitro assays and RNA-seq analysis, along with quantitative multi-photon microscopy to study NK cell migration in 3D collagen matrices and ex vivo live tumors. In Aim 2, we propose additional in vivo studies in xenogeneic and syngeneic mouse models to evaluate KRAS inhibition, B7-H3 TriKE and adoptive NK cell combination therapy. Based on preliminary data, we will also perform spatial proteomics on additional human PDAC specimens to examine the spatial interactions of NK cells with other cell types in the TME and identify barriers to NK cell infiltration. Overall, this proposal aims to discover novel mechanisms of NK cell regulation in PDAC and provide pre-clinical evidence for a KRAS inhibitor and B7-H3 NK engager therapy for patients. This proposal provides new multidisciplinary training in tumor immunology, cell therapy, cancer bioengineering, data modeling and multi-omics that is instrumental for my future career as an academic physician-scientist in oncology. Project Number: 1F30CA301797-01A1 | Fiscal Year: 2026 | NIH Institute/Center: National Cancer Institute (NCI) | Principal Investigator: Paarth Dodhiawala | Institution: UNIVERSITY OF MINNESOTA, MINNEAPOLIS, MN | Award Amount: $47,827 | Activity Code: F30 | Study Section: Special Emphasis Panel[ZRG1 F09C-H (22)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11315344