The interplay of oral squamous cell carcinoma cells, carcinoma-associated fibroblasts and platelets in tumor invasion

• Grant number: 17/02724-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2017
• End date: May 31, 2019
• Field of knowledge: Health Sciences - Dentistry
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Ricardo Della Coletta
• Grantee: Ana Camila Pereira Messetti
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Over the past decades, it has become clear that tumor progression depends on more than the malignant cells by themselves. The microenvironment in which tumor cells are exposed is essential for tumor invasion and metastasis. Platelets released into tumor stroma due to angiogenesis and angiogenic factors associated with clotting process play an important role during tumor invasion and correlate with worse prognosis. Following tumor invasion, stroma cells become activated and fibroblasts, by the action of proteins released by the tumor and stroma-actived cells, acquire the phenotype of carcinoma-associated fibroblast (CAF). CAF secretoma modulates the proliferation and the invasive potential of tumor cells. The overall objective of this study is to increase the knowledge about tumor-stroma interactions in stimulation of events associated with the progression of oral squamous cell carcinoma (OSCC). Our strategy is to mimic the tumor microenvironment through organotypic cultures involving co-culturing OSCC cells, CAFs and platelets. To better understand these interactions, we have compiled the following aims: 1) to verify whether the secretome from OSCC cells and CAFs in monoculture and co-culture are able of inducing platelet activation and aggregation; 2) to evaluate the role of platelet-rich plasma (PRP), washed platelets (WP) and plasma poor in platelets (PPP, group to be used for comparison) in the induction of invasion and epithelial-mesenchymal transition (EMT) of OSCCs, in addition to evaluating the secretome released by the co-cultures to detect cytokines, chemokines and growth factors involved in induction of these phenotypes; 3) to determine the effect of PRP, WP and PPP in transition from normal oral fibroblasts in CAFs and analyze the involvement of TGF-²1, PDGF and CXCL12/SDF-1 receptors, molecules known to induce this process, in the transition of fibroblasts in CAFs; 4) to verify the existence of additive pro-invasive effects of co-cultures of OSCC cells, CAFs and platelets, and to characterize the potential mediators of these effects, 5) to evaluate whether the cellular interactions (co-cultures) induce angiogenesis in vitro, and consequently, to quantify VEGFA and their isoforms. It is important to note that several studies point to the stroma as an excellent therapeutic target for OSCC, however little is known about the interactions with tumor cells and the mechanisms that control their activation, limiting this possibility therapy. (AU)