Hepato-pancreato-biliary
Neil Blok, MD, PhD
General Surgery Resident
Department of Surgery, University of Michigan, United States
Neil Blok, MD, PhD
General Surgery Resident
Department of Surgery, University of Michigan, United States
Neil Blok, MD, PhD
General Surgery Resident
Department of Surgery, University of Michigan, United States
Brian D. Griffith, MD (he/him/his)
General Surgery Resident
Department of Surgery, University of Michigan
Ann Arbor, Michigan, United States
J. Lawrence Delrosario, MD
Anesthesia Resident
Stanford University, United States
Zeribe Nwosu, PhD
Research Fellow
University of Michigan, United States
Lei Sun, PhD
Senior Scientist
Department of Surgery, University of Michigan, United States
Samantha Bell, MS, LVT
Data Analyst
National Veterinary Associates, United States
Robert O'Rourke, MD, FACS
William J Fry Professor of Surgery
Department of Surgery, University of Michigan; Department of Surgery, Ann Arbor Veterans Affairs Healthcare System, United States
Timothy L. Frankel, MD, FACS
Maud T Lane Professor of Surgical Oncology
Department of Surgery, University of Michigan; Department of Surgery, Ann Arbor Veterans Affairs Healthcare System, United States
Type 2 diabetes mellitus is one of the strongest risk factors for pancreatic adenocarcinoma (PDAC). Here we identify molecular mediators of this increased PDAC risk in diabetic patients.
Methods:
Patient derived preadipocytes isolated from diabetic and non-diabetic patient visceral adipose tissue were cultured in vitro. We measured proliferative effects of conditioned media from these cells when applied to PDAC cells in vitro. These preadipocytes were also co-xenografted with PDAC cells in mice. We utilized multiplex cytokine profiling of preadipocyte conditioned media and bulk RNA-Seq on patient visceral adipose tissue to explore factors enriched in diabetes. Neutralizing antibodies and recombinant protein were used to study the effects of each identified factor in the experimental models outlined above. We identified signaling pathways activated in PDAC using phosphokinome profiling and RNA-Seq.
Results:
We applied conditioned media from diabetic patient-derived preadipocytes to PDAC cells in vitro. This media had significantly higher proliferative effects than when we used similar samples from non-diabetics. We then co-xenografted patient-derived preadipocytes with PDAC cells into mice. Diabetic preadipocytes enhanced PDAC growth far more than preadipocytes from non-diabetic patients. To elucidate the mechanism of this effect we searched for proteins enriched in diabetic versus non-diabetic preadipocyte conditioned media. Interleukin-6 (IL6) and chitinase-3 like-protein-1 (Chi3L1) are among the two most highly enriched proteins as assessed by multiplex ELISA-based cytokine profiling of conditioned media. This was confirmed by bulk RNA-Seq of human visceral adipose tissue. Recombinant IL6 and Chi3L1 each augmented the proliferative effect of non-diabetic media on PDAC to the level of diabetic media. Neutralizing antibodies to either IL6 and Chi3L1 ablated the effect of diabetic conditioned media on PDAC growth in vitro. Similar experiments demonstrated that CD44 on PDAC cells is a downstream effector of the proliferative effects of both IL6 and Chi3L1. Finally, we employed phosphokinome arrays, ELISA, and RNA-Seq on PDAC cells to show that PI3K/AKT, ERK, RTK, and other known proliferation- and tumorigenesis-inducing pathways are activated in the diabetic context.
Conclusions:
We show that the diabetic milieu promotes PDAC tumorigenesis through the inflammation-related factors IL6 and Chi3L1 in a CD44 dependent fashion. These data demonstrate a molecular mechanism by which diabetes confers risk of PDAC.