Biology subjects

Kinsey, C. G.

Publications and source records attributed to Kinsey, C. G..

3 recordsLinked to original sources

bioRxiv2025

Genetic Drivers of Sensitivity or Resistance to RAS(ON) Multi-Selective Inhibitors in NRAS-Mutated Melanoma

Most patients with advanced BRAF or NRAS-driven melanoma receive front-line immunotherapy. However, if immunotherapy fails, BRAF-mutated patients have effective second-line therapies, whereas NRAS-mutated patients lack pathway-targeted options. Recently, RAS(ON) multi-selective inhibitors like RMC-7977, and the investigational agent daraxonrasib, were described that, in partnership with cyclophilin-A (CYPA), inhibit RAS[GTP] signaling. Both compounds demonstrate potent anti-proliferative activity against NRAS-mutated melanoma cell lines and robust anti-tumor activity against preclinical melanoma models. However, in preclinical models, resistance to RMC-7977 monotherapy arose through mutations in Ppia (encoding CYPA) or Map2k1 (encoding MEK1). Moreover, two clinical case studies in patients with NRAS-mutated melanoma treated with daraxonrasib demonstrated clear anti-tumor activity in one patient, but progressive disease in another with co-occurring NRAS and MAP2K1 mutations at baseline. These findings support the potential for daraxonrasib in treatment of patients with NRAS-mutated melanoma, and reveal candidate mechanisms of monotherapy resistance, underscoring the need for combination therapies to improve outcomes. SIGNIFICANCEThere are no pathway-targeted therapies for patients with NRAS-mutated melanoma. Here we demonstrate that direct pharmacological inhibition of RAS[GTP] with RMC-7977 or daraxonrasib (RMC-6236) has profound inhibitory effects in preclinical models of NRAS-mutated melanoma. Furthermore, we identify mechanisms of resistance to RMC-7977 through mutational inactivation of CYPA or mutational activation of MEK1.

cancer biology↗

bioRxiv2025

BRAFV600E-Driven Lung Tumorigenesis Requires Ligand-Mediated Activation of ERBB Receptor Signaling

Secretion of ligands of the human epidermal growth factor (EGFR) family of receptors or erythroblastic leukemia viral oncogene family (ERBB1-4) is a feature common to many cancer cells. However, our understanding of the role of autocrine ligands in the aberrant behavior of cancer remains incomplete. Here we demonstrate that, in numerous preclinical models of lung tumorigenesis, BRAFV600E signaling promotes expression of ligands including HB-EGF, TGF, Epi- and Amphiregulin. Moreover, using both genetic or pharmacological approaches, we demonstrate that ligand-mediated activation of EGFR signaling in the tumor cell is required to sustain both early-stage BRAFV600E-driven lung tumorigenesis and supports late-stage BRAFV600E-driven lung cancer maintenance. Unbiased Reverse Phase Protein Analyses (RPPA) analyses, paired with targeted validation, reveals ERBB signaling serves to sustain signaling through the ERK1/2 MAP kinase pathway, through effects on ARAF and CRAF, and on the parallel JUN kinase (JNK) pathway. Furthermore, EGFR is activated in a cohort of BRAF-mutated lung cancer patients both pre- and post-treatment. Finally, we noted significant improvement in the depth and durability of therapeutic responses in preclinical models of BRAFV600E-driven lung cancer by combined inhibition of both BRAFV600E signaling plus pan-ERBB signaling. Collectively, this work provides evidence for an important role for ERBB family signaling in the genesis and maintenance of BRAFV600E-driven lung cancers, and the potential for future therapeutic improvement by rational combination targeting of these pathways. SIGNIFICANCEBRAFT1799A serves as a predictive biomarker for FDA-approved targeted inhibition of BRAFV600E oncoprotein kinase signaling in non-small cell lung cancer (NSCLC). However the occurrence of primary or acquired drug resistance limit the depth and durability of patient responses. Studies described here provide a mechanistic rationale for clinical testing of first-line BRAFV600E inhibition combined with pan-ERBB inhibition to improve the depth and durability of initial patient responses, and delay the emergence of lethal drug resistant disease.

cancer biology↗

bioRxiv2024

Inhibition of ULK1/2 and KRASG12C controls tumor growth in preclinical models of lung cancer

Mutational activation of KRAS occurs commonly in lung carcinogenesis and, with the recent FDA approval of covalent inhibitors of KRASG12C such as sotorasib or adagrasib, KRAS oncoproteins are important pharmacological targets in non-small cell lung cancer (NSCLC). However, not all KRASG12C-driven NSCLCs respond to these inhibitors, and the emergence of drug resistance in those patients that do respond can be rapid and pleiotropic. Hence, based on a backbone of covalent inhibition of KRASG12C, efforts are underway to develop effective combination therapies. Here we report that inhibition of KRASG12C signaling increases autophagy in KRASG12C expressing lung cancer cells. Moreover, the combination of DCC-3116, a selective ULK1/2 inhibitor, plus sotorasib displays cooperative/synergistic suppression of human KRASG12C-driven lung cancer cell proliferation in vitro and superior tumor control in vivo. Additionally, in genetically engineered mouse models of KRASG12C-driven NSCLC, inhibition of either KRASG12C or ULK1/2 decreases tumor burden and increases mouse survival. Consequently, these data suggest that ULK1/2-mediated autophagy is a pharmacologically actionable cytoprotective stress response to inhibition of KRASG12C in lung cancer.

cancer biology↗