Citation

  • Authors: Wang, T., Chen, Y., Ronald, J. A.
  • Year: 2019
  • Journal: Gene Ther 26 177-186
  • Applications: in vivo / tumour-activatable minicircles (TA-MCs) / in vivo-jetPEI

Method

Biomolecule: a gene-based cancer detection system called tumour-activatable minicircles (TA-MCs). We used it to detect melanoma lung metastases in mice with a sensitive and relatively affordable blood reporter assay. Mice were injected with TA-MCs when tumours reached ~150 mm3. TA-MCs (25 μg/mouse) were complexed with 2.4 μL of linear polyethylenimine to achieve an N/P ratio of 6. This DNA–jetPEI complex was then resuspended in 50 μL 10% (w/v) glucose. Mice were anesthetised with 2% isoflurane then IT injections were performed by injecting the MC-PEI complexes into 4 or 5 loci of each tumour.

Abstract

Early and accurate detection of cancer is essential to optimising patient outcomes. Of particular importance to prostate cancer is the ability to determine the aggressiveness of a primary tumour, which allows for effective management of patient care. In this work, we propose using gene vectors called tumour-activatable minicircles which deliver an exogenously encoded reporter gene into cancer cells, forcing them to produce a unique and sensitive biomarker. These minicircles express a blood reporter protein called secreted embryonic alkaline phosphatase mediated by the tumour-specific survivin promoter, which exhibits activity graded to prostate cancer aggressiveness. Together, these components underlie a detection system where levels of blood reporter are indicative of not only the presence, but also the metastatic potential of a tumour. Our goal was to assess the ability of tumour-activatable minicircles to detect and characterise primary prostate lesions. Our minicircles produced reporter levels related to survivin expression across a range of prostate cancer cell lines. When survivin-driven minicircles were administered intratumourally into mice, reporter levels in blood samples were significantly higher (p < 0.05) in mice carrying prostate tumours of high versus low-aggressiveness. Continued development of this gene-based system could provide clinicians with a powerful tool to evaluate prostate cancer aggressiveness using a sensitive and affordable blood assay.

Pubmed