Pancreatic cancer collagen-based optical signatures

Cancer progression is closely related to changes in the structure and mechanical properties of the tumor microenvironment in a complex and not well-understood manner. In many solid tumors, including pancreatic cancer, the complex interplay among the different components of tumor microenvironment leads to a desmoplastic reaction associated with fibroblasts activation and collagen overproduction. Desmoplasia is responsible for tumor stiffening, and poses a major barrier to the effective delivery of drugs and has been associated with poor prognosis. Thus, the understanding of the involved mechanisms and the identification of collagen-based signatures that characterize the state of a particular tumor can lead to the development of novel diagnostic and prognostic biomarkers. In this study, pancreatic tumor models were developed employing the human pancreatic cancer cell lines BxPc-3 and MIAPaCa-2 and tissue biopsies were obtained at different stages of cancer progression. Polarized microscopy on picrosirius red stained tumor sections was used in order to assess collagen-based optical signatures in correlation with tumor progression, while Atomic Force Microscopy (AFM) was applied for the nano-mechanical characterization of the samples. The results demonstrated that pancreatic cancer presents unique collagen-based characteristics that can be used as a novel biomarker for cancer diagnosis and prognosis.