Cancer-associated fibroblast-derived extracellular vesicles promote pancreatic cancer progression via the RAP1B/ANLN axis

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies worldwide, characterized by late diagnosis, rapid progression and resistance to conventional therapies. Cancer-associated fibroblast (CAF)-derived extracellular vesicles (EVs) contribute to PDAC progression, but their downstream molecular effectors remain unclear. In the present study, it was demonstrated that CAF-derived EVs enhanced the proliferative, migratory and invasive capacity of PDAC cells across two independent cell lines, as assessed by Cell Counting Kit-8 assays and Transwell migration and Matrigel invasion assays. RAP1B was identified as a prominently upregulated protein by label-free proteomic profiling following EV exposure. High RAP1B expression, evaluated by immunohistochemistry, in a cohort of 77 resected PDAC specimens tended to be more frequent with advancing pathological stage and was associated with poorer overall survival. RAP1B knockdown using small interfering RNA suppressed proliferation and motility in PDAC cells and induced cytokinesis failure characterized by multinucleation and cytoskeletal abnormalities, as demonstrated by time-lapse imaging and immunofluorescence staining. Proteomic profiling of RAP1B-knockdown cells identified anillin (ANLN) as a downstream mediator; ANLN knockdown recapitulated these cytokinetic defects, whereas ANLN knockdown did not reciprocally affect RAP1B levels, establishing a unidirectional RAP1B/ANLN axis. Furthermore, RAP1B depletion sensitized PDAC cells to gemcitabine, showing additive growth inhibition. In conclusion, CAF-derived EVs mediate PDAC progression via the RAP1B/ANLN axis, representing a novel and promising therapeutic target in PDAC.