Intravital Imaging to Monitor Therapeutic Response in Moving Hypoxic Regions Resistant to PI3K Pathway Targeting in Pancreatic Cancer

Cell Rep. 2018 Jun 12;23(11):3312-3326. doi: 10.1016/j.celrep.2018.05.038.

Abstract

Application of advanced intravital imaging facilitates dynamic monitoring of pathway activity upon therapeutic inhibition. Here, we assess resistance to therapeutic inhibition of the PI3K pathway within the hypoxic microenvironment of pancreatic ductal adenocarcinoma (PDAC) and identify a phenomenon whereby pronounced hypoxia-induced resistance is observed for three clinically relevant inhibitors. To address this clinical problem, we have mapped tumor hypoxia by both immunofluorescence and phosphorescence lifetime imaging of oxygen-sensitive nanoparticles and demonstrate that these hypoxic regions move transiently around the tumor. To overlay this microenvironmental information with drug response, we applied a FRET biosensor for Akt activity, which is a key effector of the PI3K pathway. Performing dual intravital imaging of drug response in different tumor compartments, we demonstrate an improved drug response to a combination therapy using the dual mTORC1/2 inhibitor AZD2014 with the hypoxia-activated pro-drug TH-302.

Keywords: AZD2014; Akt; FRET; PI3K pathway; PLIM; hypoxia; intravital imaging; nanoparticles; pancreatic cancer; pro-drug.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Benzamides
  • Cell Line, Tumor
  • Drug Resistance, Neoplasm* / drug effects
  • Drug Therapy, Combination
  • Female
  • Fluorescence Resonance Energy Transfer
  • Humans
  • Hypoxia
  • Intravital Microscopy / methods
  • Mice
  • Mice, Inbred BALB C
  • Morpholines / pharmacology
  • Morpholines / therapeutic use
  • Nanoparticles / chemistry
  • Nitroimidazoles / pharmacology
  • Nitroimidazoles / therapeutic use
  • Pancreatic Neoplasms / drug therapy
  • Pancreatic Neoplasms / metabolism
  • Pancreatic Neoplasms / pathology
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphoramide Mustards / pharmacology
  • Phosphoramide Mustards / therapeutic use
  • Proto-Oncogene Proteins c-akt / metabolism
  • Pyrimidines
  • Signal Transduction* / drug effects
  • Transplantation, Heterologous
  • Tumor Microenvironment

Substances

  • Benzamides
  • Morpholines
  • Nitroimidazoles
  • Phosphoramide Mustards
  • Pyrimidines
  • TH 302
  • vistusertib
  • Proto-Oncogene Proteins c-akt