Apolipoprotein A-II Plus Lipid Emulsion Enhance Cell Growth via SR-B1 and Target Pancreatic Cancer In Vitro and In Vivo

Sohel M Julovi; Aiqun Xue; Thao N Thanh LE; Anthony J Gill; Jerikho C Bulanadi; Mili Patel; Lynne J Waddington; Kerry-Anne Rye; Minoo J Moghaddam; Ross C Smith

doi:10.1371/journal.pone.0151475

Apolipoprotein A-II Plus Lipid Emulsion Enhance Cell Growth via SR-B1 and Target Pancreatic Cancer In Vitro and In Vivo

PLoS One. 2016 Mar 22;11(3):e0151475. doi: 10.1371/journal.pone.0151475. eCollection 2016.

Authors

Sohel M Julovi¹, Aiqun Xue¹, Thao N Thanh LE¹, Anthony J Gill², Jerikho C Bulanadi^{1

3}, Mili Patel⁴, Lynne J Waddington⁵, Kerry-Anne Rye⁴, Minoo J Moghaddam³, Ross C Smith^{1

6}

Affiliations

¹ Cancer Surgery Group, Kolling Institute of Medical Research, University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia.
² Cancer Diagnosis and Pathology Research Group, Kolling Institute of Medical Research,University of Sydney at Royal North Shore Hospital, St Leonards, New South Wales, Australia.
³ CSIRO Manufacturing, CSIRO, North Ryde, New South Wales, Australia.
⁴ Centre for Vascular Research, Faculty of Medicine, University of New South Wales, New South Wales, Australia.
⁵ CSIRO Manufacturing, CSIRO, Parkville, Victoria, Australia.
⁶ Department of Gastrointestinal Surgery, Royal North Shore Hospital, St Leonards, New South Wales, Australia.

Abstract

Background: Apolipoprotein A-II (ApoA-II) is down regulated in the sera of pancreatic ductal adenocarcinoma (PDAC) patients, which may be due to increase utilization of high density lipoprotein (HDL) lipid by pancreatic cancer tissue. This study examined the influence of exogenous ApoA-II on lipid uptake and cell growth in pancreatic cancer (PC) both in vitro and in vivo.

Methods: Cryo transmission electron microscopy (TEM) examined ApoA-II's influence on morphology of SMOFLipid emulsion. The influence of ApoA-II on proliferation of cancer cell lines was determined by incubating them with lipid+/-ApoA-II and anti-SR-B1 antibody. Lipid was labeled with the fluorophore, DiD, to trace lipid uptake by cancer cells in vitro by confocal microscopy and in vivo in PDAC patient derived xenograft tumours (PDXT) by fluorescence imaging. Scavenger receptor class B type-1(SR-B1) expression in PDAC cell lines and in PDAC PDXT was measured by western blotting and immunohistochemistry, respectively.

Results: ApoA-II spontaneously converted lipid emulsion into very small unilamellar rHDL like vesicles (rHDL/A-II) and enhanced lipid uptake in PANC-1, CFPAC-1 and primary tumour cells as shown by confocal microscopy. SR-B1 expression was 13.2, 10.6, 3.1 and 2.3 fold higher in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cell lines than the normal pancreatic cell line (HPDE6) and 3.7 fold greater in PDAC tissue than in normal pancreas. ApoA-II plus lipid significantly increased the uptake of labeled lipid and promoted cell growth in PANC-1, MIAPaCa-2, CFPAC-1 and BxPC3 cells which was inhibited by anti SR-B1 antibody. Further, ApoA-II increased the uptake of lipid in xenografts by 3.4 fold.

Conclusion: Our data suggest that ApoA-II enhance targeting potential of lipid in pancreatic cancer which may have imaging and drug delivery potentialities.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Apolipoprotein A-II / metabolism*
Carcinoma, Pancreatic Ductal / metabolism
Cell Line, Tumor
Cell Proliferation / physiology*
Humans
Lipids / physiology*
Lipoproteins, HDL / metabolism
MCF-7 Cells
Pancreatic Neoplasms / metabolism*
Scavenger Receptors, Class B / metabolism*

Substances

Apolipoprotein A-II
Lipids
Lipoproteins, HDL
SCARB1 protein, human
Scavenger Receptors, Class B

Grants and funding

Part of this study was presented and awarded as best poster at New Horizons 2014 and the Scientific Research Meeting, 17th-19th November, 2014. This study has not been published elsewhere or is not under consideration for a publication. The study was supported by the CanSur foundation and partly by the Ramsay Research Teaching Fund but did not have any role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. Commercial affiliation of the authors at CSIRO did not play any role in the study and did not have any competing interests relating to employment, consultancy, patents, products in development and marketed products.