Research Papers:

ABSTRACT

There remains an unmet need for effective drugs targeting KRAS-driven cancers. Polyisoprenylated cysteinyl amide inhibitors (PCAIs) were designed to disrupt hyperactive mutant KRAS in cancer. Here, we determined the effects of PCAIs on the viability and downstream mediators of KRAS on pancreatic cancer-derived PANC-1 and MIAPaCa-2 cells. NSL-YHJ-2-45 and NSL-YHJ-2-27 were the most potent of the analogs with EC50 values of 3.6 and 3.8 μM, respectively. NSL-YHJ-2-27 treatment of PANC-1 cells stimulated BRAF, MEK 1/2, ERK 1/2 and p90RSK phosphorylation levels by 64 to 150% while CRAF phosphorylation significantly decreased by 27%. Furthermore, 5 μM NSL-YHJ-2-27 depleted 20 to 61% of the monomeric G-proteins, CDC42, RHOA and RAC 1/2/3 while increasing pAKT (Ser 473) and pAKT (Thr 308) phosphorylation by 72 and 190%, respectively. Reactive oxygen species production significantly increased at 3 μM NSL-YHJ-27 in PANC-1 and MIA PaCa-2 by 2- and 9-fold, respectively. Bulk RNA sequencing analysis revealed that treatment of MIA PaCa-2 cells with 3 μM NSL-YHJ-27 resulted in significant differential expression of 88 genes. NSLYHJ-2-27 at 1 μM inhibited over 90% of pancreatic cancer cell migration. The PCAIs induced apoptosis in both PANC-1 and MIA PaCa-2 3D spheroids while doubling caspase 3/7 activity in PANC-1 cells. Taken together, these data obtained using pancreatic cancer cells with KRAS mutations suggest the ability of the PCAIs to prevent metastasis and tumor growth, strongly indicating their potential to serve as effective targeted therapies for treating cancer types driven by the multiple mutant forms of KRAS.