GNPX 2017 Annual Report

13 In addition, an in situ proximity ligation assay, or PLA, performed on paired biopsies from three subjects, demonstrated no TUSC2 protein staining in pre-treatment tissues compared with intense TUSC2 protein staining in post-treatment tissues. For the PLA, anti-TUSC2 polyclonal antibodies were developed to detect the presence of TUSC2. Pre-treatment and post-treatment biopsies were obtained from three patients. The top panel for each patient in the illustration below represents the pre-treatment biopsy “controls” with DAPI, a type of blue stain. The bottom panel for each patient are post-treatment biopsies, and represent overlays of blue DAPI staining and red anti-TUSC2 antibody staining. The blue stains in the top panels indicate the absence of TUSC2 in the pre-treatment biopsies, and the red and purple (red overlaying blue) stains in the bottom panels indicate the presence of TUSC2 in robust quantities in the post-treatment biopsies, showing that TUSC2 was successfully introduced into the tumors in the Phase I Monotherapy Trial. Proximity Ligation Assay (PLA) for TUSC2 protein in tumor biopsies