International Journal of Molecular Sciences Review Pancreatic Cancer and Its Microenvironment—Recent Advances and Current Controversies 1, 2, 2 2, Kinga B. Stopa y , Agnieszka A. Kusiak y, Mateusz D. Szopa , Pawel E. Ferdek * and Monika A. Jakubowska 1,* 1 Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7A, 30-387 Krakow, Poland;
[email protected] 2 Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Krakow, Poland;
[email protected] (A.A.K.);
[email protected] (M.D.S.) * Correspondence:
[email protected] (P.E.F.);
[email protected] (M.A.J.) These authors contributed equally to this work. y Received: 9 April 2020; Accepted: 29 April 2020; Published: 1 May 2020 Abstract: Pancreatic ductal adenocarcinoma (PDAC) causes annually well over 400,000 deaths world-wide and remains one of the major unresolved health problems. This exocrine pancreatic cancer originates from the mutated epithelial cells: acinar and ductal cells. However, the epithelia-derived cancer component forms only a relatively small fraction of the tumor mass. The majority of the tumor consists of acellular fibrous stroma and diverse populations of the non-neoplastic cancer-associated cells. Importantly, the tumor microenvironment is maintained by dynamic cell-cell and cell-matrix interactions. In this article, we aim to review the most common drivers of PDAC. Then we summarize the current knowledge on PDAC microenvironment, particularly in relation to pancreatic cancer therapy. The focus is placed on the acellular stroma as well as cell populations that inhabit the matrix.