Mentors

Lily Wu, M.D., Ph.D.
Arion Chatziioannou, Ph.D.

Research Interests:

Title: Engineering adenoviral vectors to express the cell cycle regulator p27kip1 in a two-step transcription amplification (TSTA) system for prostate cancer gene therapy

The most frequent molecular events involved in prostate carcinogenesis are associated with the androgen-refractory stage of the disease and include downregulation of p27kip1. We are utilizing the two-step transcription amplification (TSTA) system to express p27 and a ubiquitin proteasome pathway degradation-resistant mutated p27 (p27T187A) molecules as therapeutic strategies for prostate cancer. The TSTA system consists of two-constructs, one containing a prostate-specific promoter driving the expression of a chimeric activator (GAL4-VP16), and a target construct containing five GAL4-binding sites upstream of the therapeutic and/or reporter gene. For this purpose, we are generating a Single System TSTA Ad vector (Ad-p27-G5-FL/PS-VP2) for directing amplified and prostate-specific expression of p27 or p27T187A and firefly luciferase (FL) reporter gene. This all-in-one recombinant adenoviral vector contains a GAL4-responsive bi-directional p27 and FL expression cassette inserted into viral E1 region and the prostate-specific activator inserted into the viral E3 region. Preliminary data of the Single System FL reporter vector (Ad-G5-FL/PS-VP2) in the same vector genome configuration but lacking p27 showed that it exhibited very low non-specific expression and high androgen inducibility.

For in vivo studies, prostate cancer tumors (CWR22Rv1 and LNCaP) will be transduced with a lentiviral vector to stably express renilla luciferase. This approach aims to facilitate the monitoring of in vivo tumor establishment, growth rate, and therapeutic effects of gene therapy by optical imaging using coelanterazine as a substrate. Conversely, upon injection of Adp27-G5-FL/PS-VP2 into the tumor, vector-mediated gene expression can be monitored in vivo by optical imaging using D-luciferin as a substrate. We believe that coupling the prostate-targeted gene therapy with multi-level, non-invasive imaging affords us a sensitive, real-time assessment of therapeutic activity in the living subject. If successful, this promising pre-clinical therapeutic approach can be further adapted for PET imaging and potentially translated to clinical settings.

Assistant Professor, Department of Comparative Biomedical Sciences;
Louisiana State University School of Veterinary Medicine