Novel Peptide-1 targets KRASG12V, showing potent antiproliferative activity in colorectal cancer cells

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, highlighting an urgent need for more selective and safer therapeutic options. Despite its critical role in CRC, specific inhibitors for the KRASG12V mutation are severely limited, leaving a significant therapeutic gap. Biomimetic peptides offer a promising alternative to conventional chemotherapeutics due to their high specificity and potential for reduced off-target effects. This study explores a novel peptide's potential to selectively target KRASG12V, addressing a key oncogenic driver.

Researchers conducted a structure-based virtual screening of a 59,319-member peptide library to identify potential KRASG12V-targeting peptides. Among four candidates, Peptide-1 showed the most favorable docking profile. Binding affinity was confirmed using MST assays, comparing Peptide-1's interaction with KRASG12V versus other KRAS mutants. Structural analysis, molecular dynamics simulations, and free-energy calculations elucidated the binding mechanism. Cellular engagement was supported by NanoBRET assays. Functional activity was assessed by measuring antiproliferative effects in colorectal cancer cell lines, comparing them to normal cells, and evaluating efficacy after KRASG12V knockdown. In SW480 cells, ERK1/2 phosphorylation, p21 upregulation, and G0/G1 accumulation were analyzed.

Peptide-1 exhibited the highest affinity among the identified peptides (Peptides 1-4) for KRASG12V, demonstrating stronger binding to this specific mutant compared to other KRAS variants. Structural analysis confirmed that Peptide-1 forms a stable and energetically favorable complex with KRASG12V through extensive hydrogen bonding and hydrophobic interactions. Importantly, Peptide-1 showed favorable human serum stability, suggesting potential for in vivo application. Cellular NanoBRET assays further supported its engagement with KRASG12V within cells. Functionally, Peptide-1 displayed potent antiproliferative activity in colorectal cancer cell lines, while showing weaker effects on normal cells, indicating selectivity. Its efficacy was significantly reduced after KRASG12V knockdown, confirming target specificity. > In SW480 colorectal cancer cells, Peptide-1 treatment was associated with reduced ERK1/2 phosphorylation, upregulation of p21, and accumulation of cells in the G0/G1 phase, indicating cell cycle arrest.