Noninvasive molecular imaging of MYC mRNA expression in human breast cancer xenografts with a [99mTc]peptide-peptide nucleic acid-peptide chimera

Bioconjug Chem. 2005 Jan-Feb;16(1):70-9. doi: 10.1021/bc0497923.


Human estrogen receptor-positive breast cancer cells typically display elevated levels of Myc protein due to overexpression of MYC mRNA, and elevated insulin-like growth factor 1 receptor (IGF1R) due to overexpression of IGF1R mRNA. We hypothesized that scintigraphic detection of MYC peptide nucleic acid (PNA) probes with an IGF1 peptide loop on the C-terminus, and a [99mTc]chelator peptide on the N-terminus, could measure levels of MYC mRNA noninvasively in human IGF1R-overexpressing MCF7 breast cancer xenografts in nude mice. We prepared the chelator-MYC PNA-IGF1 peptide, as well as a 4-nt mismatch PNA control, by solid-phase synthesis. We imaged MCF7 xenografts scintigraphically and measured the distribution of [99mTc]probes by scintillation counting of dissected tissues. MCF7 xenografts in nude mice were visualized at 4 and 24 h after tail vein administration of the [99mTc]PNA probe specific for MYC mRNA, but not with the mismatch control. The [99mTc]probes distributed normally to the kidneys, livers, tumors, and other tissues. Molecular imaging of oncogene mRNAs in solid tumors with radiolabel-PNA-peptide chimeras might provide additional genetic characterization of preinvasive and invasive breast cancers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Breast Neoplasms / diagnostic imaging*
  • Breast Neoplasms / metabolism
  • Chimera
  • Diagnostic Imaging*
  • Disease Models, Animal
  • Female
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Mice
  • Mice, Nude
  • Neoplasm Transplantation
  • Peptide Nucleic Acids*
  • Proto-Oncogene Proteins c-myc / genetics
  • Proto-Oncogene Proteins c-myc / metabolism*
  • RNA, Messenger / analysis*
  • RNA, Messenger / metabolism
  • Radiography
  • Receptor, IGF Type 1 / metabolism
  • Technetium Tc 99m Sestamibi*
  • Time Factors
  • Tissue Distribution
  • Tumor Cells, Cultured
  • Xenograft Model Antitumor Assays*


  • Peptide Nucleic Acids
  • Proto-Oncogene Proteins c-myc
  • RNA, Messenger
  • Technetium Tc 99m Sestamibi
  • Receptor, IGF Type 1