Exosomes in pancreatic juice as valuable source of biomarkers for early diagnosis of pancreatic cancer

Pancreatic cancer (PC) is a deadly malignancy which continues to have a high mortality rate despite advances in imaging and treatment modalities. The poor prognosis of PC is largely attributed to the silent nature of early disease. Early PC is largely asymptomatic, or presents with generalised symptoms such as abdominal pain. Due to late diagnosis, patients are unable to reap the full benefits of treatments, such as surgery. It is thus imperative to develop non-invasive, specific, and sensitive biomarkers to aid diagnosis of PC in the early stages. Pancreatic juice is a promising biofluid in the area of diagnostics. Several cancer-specific molecules, e.g., proteins and RNA have been identified in samples from cancer patients. Additionally, extracellular vesicles (EVs) in various body fluids have recently emerged as an important carrier of tissue and disease specific molecules in the context of other pathologies. EVs are membrane-bound sacs of molecular cargo, such as proteins, miRNA, and RNA. With a size range of approximately 40-100 nm, exosomes are a unique type of EV which traffic molecular cargo from the cell-of-origin to targeted sites in the body. Exosomes are derived from the endocytic origin, which means vesicular contents are cell-specific and may represent a signature of cellular pathology. Hence, we propose that exosomes derived from pancreatic juice may capture a pinpointed set of pathological biomarkers to assist in the diagnosis of PC. This is especially pertinent in the context of early disease, as exosomes trafficked within pancreatic juice may facilitate the development of a pre-metastatic niche well before any symptomology.