Activation of carbonic anhydrase IX by alternatively spliced tissue factor under late-stage tumor conditions

Lab Invest. 2016 Dec;96(12):1234-1245. doi: 10.1038/labinvest.2016.103. Epub 2016 Oct 10.

Abstract

Molecules of the coagulation pathway predispose patients to cancer-associated thrombosis and also trigger intracellular signaling pathways that promote cancer progression. The primary transcript of tissue factor, the main physiologic trigger of blood clotting, can undergo alternative splicing yielding a secreted variant, termed asTF (alternatively spliced tissue factor). asTF is not required for normal hemostasis, but its expression levels positively correlate with advanced tumor stages in several cancers, including pancreatic adenocarcinoma. The asTF-overexpressing pancreatic ductal adenocarcinoma cell line Pt45.P1/asTF+ and its parent cell line Pt45.P1 were tested for growth and mobility under normoxic conditions that model early-stage tumors, and in the hypoxic environment of late-stage cancers. asTF overexpression in Pt45.P1 cells conveys increased proliferative ability. According to cell cycle analysis, the major fraction of Pt45.P1/asTF+ cells reside in the dividing G2/M phase of the cell cycle, whereas the parental Pt45.P1 cells are mostly confined to the quiescent G0/G1 phase. asTF overexpression is also associated with significantly higher mobility in cells plated under either normoxia or hypoxia. A hypoxic environment leads to upregulation of carbonic anhydrase IX (CAIX), which is more pronounced in Pt45.P1/asTF+ cells. Inhibition of CAIX by the compound U-104 significantly decreases cell growth and mobility of Pt45.P1/asTF+ cells in hypoxia, but not in normoxia. U-104 also reduces the growth of Pt45.P1/asTF+ orthotopic tumors in nude mice. CAIX is a novel downstream mediator of asTF in pancreatic cancer, particularly under hypoxic conditions that model late-stage tumor microenvironment.

MeSH terms

  • Alternative Splicing* / drug effects
  • Animals
  • Antigens, Neoplasm / chemistry
  • Antigens, Neoplasm / genetics
  • Antigens, Neoplasm / metabolism*
  • Antineoplastic Agents / pharmacology
  • Antineoplastic Agents / therapeutic use
  • Apoenzymes / genetics
  • Apoenzymes / metabolism*
  • Carbonic Anhydrase IX / antagonists & inhibitors
  • Carbonic Anhydrase IX / chemistry
  • Carbonic Anhydrase IX / genetics
  • Carbonic Anhydrase IX / metabolism*
  • Carbonic Anhydrase Inhibitors / pharmacology
  • Carbonic Anhydrase Inhibitors / therapeutic use
  • Carcinoma, Pancreatic Ductal / drug therapy
  • Carcinoma, Pancreatic Ductal / metabolism*
  • Carcinoma, Pancreatic Ductal / pathology
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Enzyme Induction / drug effects
  • G2 Phase / drug effects
  • Humans
  • Mice, Nude
  • Neoplasm Proteins / agonists
  • Neoplasm Proteins / antagonists & inhibitors
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Neoplasm Staging
  • Pancreatic Neoplasms / drug therapy
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Phenylurea Compounds / pharmacology
  • Phenylurea Compounds / therapeutic use
  • Recombinant Proteins / metabolism
  • Sulfonamides / pharmacology
  • Sulfonamides / therapeutic use
  • Thromboplastin / genetics
  • Thromboplastin / metabolism*
  • Tumor Hypoxia
  • Xenograft Model Antitumor Assays

Substances

  • Antigens, Neoplasm
  • Antineoplastic Agents
  • Apoenzymes
  • Carbonic Anhydrase Inhibitors
  • F3 protein, human
  • Neoplasm Proteins
  • Phenylurea Compounds
  • Recombinant Proteins
  • Sulfonamides
  • U-104
  • Thromboplastin
  • CA9 protein, human
  • Carbonic Anhydrase IX