Relevance of amyloid precursor-like protein 2 C-terminal fragments in pancreatic cancer cells

Int J Oncol. 2012 Oct;41(4):1464-74. doi: 10.3892/ijo.2012.1553. Epub 2012 Jul 13.

Abstract

In some cellular systems, particularly neurons, amyloid precursor-like protein 2 (APLP2), and its highly homologous family member amyloid precursor protein (APP), have been linked to cellular growth. APLP2 and APP undergo regulated intramembrane proteolysis to produce C-terminal fragments. In this study, we found comprehensive expression of APLP2 C-terminal fragments in a panel of pancreatic cancer cell lines; however, APP C-terminal fragments were notably limited to the BxPC3 cell line. Extensive glycosaminoglycan modification on APLP2 was also found in the majority of pancreatic cancer cell lines. Glycosaminoglycan-modified and -unmodified APLP2, and particularly APLP2 C-terminal fragments, also demonstrated increased expression in oncogene-transformed pancreatic ductal cells. Additionally, elevated APLP2 levels were confirmed in human pancreatic cancer tissue. Downregulation of APLP2 and APP expression, alone or in combination, caused a decrease in the growth of a pancreatic cancer cell line with representatively low APP C-terminal fragment expression, the S2-013 cell line. Furthermore, we found that treatment with β-secretase inhibitors to block formation of APLP2 C-terminal fragments decreased the growth and viability of S2-013 cells, without affecting the survival of a non-transformed pancreatic ductal cell line. In conclusion, our studies demonstrate that abundant APLP2, but not APP, C-terminal fragment expression is conserved in pancreatic cancer cell lines; however, APP and APLP2 equally regulated the growth of S2-013 pancreatic cancer cells. Chiefly, our discoveries establish a role for APLP2 in the growth of pancreatic cancer cells and show that inhibitors preventing APLP2 cleavage reduce the viability of pancreatic cancer cells.

Publication types

  • Research Support, American Recovery and Reinvestment Act
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid Precursor Protein Secretases / antagonists & inhibitors
  • Amyloid Precursor Protein Secretases / metabolism
  • Amyloid beta-Protein Precursor / antagonists & inhibitors
  • Amyloid beta-Protein Precursor / biosynthesis
  • Amyloid beta-Protein Precursor / genetics*
  • Cell Differentiation / genetics*
  • Cell Line, Tumor
  • Cell Proliferation
  • Cell Survival / genetics
  • Down-Regulation
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Nerve Tissue Proteins / antagonists & inhibitors
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / genetics*
  • Neurons / metabolism
  • Neurons / pathology
  • Pancreatic Neoplasms / genetics*
  • Pancreatic Neoplasms / pathology
  • Proteolysis

Substances

  • APLP2 protein, human
  • APP protein, human
  • Amyloid beta-Protein Precursor
  • Nerve Tissue Proteins
  • Amyloid Precursor Protein Secretases