Akama, T. | bioRxiv Science

bioRxiv2021

Recruitment of KRAS downstream target ARL4C to membrane protrusions accelerates pancreatic cancer cell invasion.

Pancreatic cancer (PC) has a high mortality rate due to metastasis. Whereas KRAS is mutated in most PC patients, controlling KRAS or its downstream effectors has not been succeeded clinically. ARL4C is a small G protein whose expression is induced by the Wnt and EGF-RAS pathways. In the present study, we found that ARL4C is frequently overexpressed in PC patients and showed that its unique localization to membrane protrusions is required for cancer cell invasion. IQGAP1 was identified as a novel interacting protein for ARL4C. ARL4C recruited IQGAP1 and its downstream effector, MMP14, to membrane protrusions. Specific localization of ARL4C, IQGAP1, and MMP14 was the active site of invasion, which induced degradation of the extracellular matrix. Moreover, subcutaneously injected antisense oligonucleotide (ASO) against ARL4C into tumor-bearing mice suppressed metastasis of PC. These results suggest that ARL4C-IQGAP1-MMP14 signaling is activated at membrane protrusions of PC cells.

cancer biology↗

bioRxiv2020

Development of an orally-administrable tumor vasculature-targeting therapeutic using annexin A1-binding D-peptides

IF7 peptide, which binds to the annexin A1 (ANXA1) N-terminal domain, functions as a tumor vasculature-targeted drug delivery vehicle after intravenous injection. To enhance IF7 stability in vivo, we undertook mirror-image peptide phage display using a synthetic D-peptide representing the Anxa1 N-terminus as target. Peptide sequences were identified, synthesized as D-amino acids, and designated as dTIT7, which was shown to bind the ANXA1 N-terminus. Whole body imaging of mouse brain tumors modeled with near infrared fluorescent IRDye-conjugated dTIT7 showed fluorescent signals in brain and kidney. Furthermore, orally-administered geldanamycin (GA)-conjugated dTIT7 suppressed brain tumor growth. Ours is a proof-of-concept experiment showing that Anxa1-binding D-peptide could be developed as an orally-administrable, tumor vasculature-targeted therapeutic. Role of each author: MN designed and performed experiments, analyzed data, and wrote the manuscript; HMA and DLJ produced recombinant ANXA1 protein; KY conducted NMR analysis and data analysis; TOA designed, performed and analyzed LC-MS/MS data; MN, TS, IKT, YS, and TY analyzed peptide-binding assays and performed in silico structural analysis; CTU produced lentivirus for luciferase expression; CNH performed peptide binding assays, tissue culture and animal experiments; and MNF supervised the project and wrote the manuscript.

pharmacology and toxicology↗