I. A. Naqvi1, R. Gunaratne1, J. Yeh4, D. Pisetsky5, B. Sullenger2, R. White3 1Duke University Medical Center,School Of Medicine,Durham, NC, USA 2Duke University Medical Center,Department Of Surgery,Durham, NC, USA 3University Of California – San Diego,Department Of Surgery,San Diego, CA, USA 4University Of North Carolina At Chapel Hill,School Of Medicine,Chapel Hill, NC, USA 5Duke University Medical Center,Department Of Medicine,Durham, NC, USA
Introduction: Pancreatic cancer (PC) has the worst prognosis of the major cancers. Metastatic progression is one of the main reasons PC is so deadly. Microparticles (MPs) and exosomes (EXOs) are cell-derived lipid particles derived from the plasma membrane and endoplasmic reticulum, respectively. Recent work has shown that intercellular communication via MPs and EXOs may play a role in tumor progression. We investigated the functional effects of tumor-derived MPs and EXOs on a pancreatic cancer cell line derived from a genetically engineered mouse model (KPC).
Methods: KPC cells were cultured in EXO-free media at 100% confluence for 72 hours after which cell supernatant was collected and centrifuged at 20,000g to isolate MPs and further at 120,000g to isolate EXO. Effects of MPs and EXO on cellular invasion were quantified by Transwell Matrigel-Invasion assay. Briefly, cells were plated in the upper chamber of a Transwell chamber with either MPs, EXO, or vehicle control and allowed to invade for 24 hours. The Transwell membrane was then fixed and stained with crystal violet. Invaded cells were quantified using Image-J software. The effects of MPs and EXO on intracellular signaling were investigated via western blot.
Results: We observed that treating KPC cells with tumor cell-derived MPs and EXOs significantly increased their invasiveness in the Transwell Matrigel-Invasion Assay Figure 1A and 1B). We also observed that treating with MPs and EXOs caused increased phosphorylation of both p65 NFkB and p-38 MAPK, both known to be important mediators of tumor progression.
Conclusion: Our results are consistent with recent work showing that MPs and EXOs may be playing a critical role in cancer progression and metastasis. Ongoing work is focused on inhibiting the effects of MPs and EXOs on cancer cells and understanding the molecular underpinnings of the effects induced by MP and EXO treatment.
