RESEARCH TOPICS

Metastasis mechanisms and novel anti-cancer therapeutics.

3B: Development of anti-bladder cancer therapeutics

2nd Generation Agents: US Patent 10588939B2

Ligand-targeted binary toxins: The EGF-toxin (Fig. on the right). Anthrax toxin has 2 subunits: the Protective Antigen (PA’: blue oval) and LFN-DTA (green triangle) subunits. The ligand EGF (red star) is fused/conjugated to PA’ targeting this toxin subunit to the EGF Receptor (EGFR). After EGFR binding, the EGF-PA’ fusion clusters receptors on the plasma membrane and recruits the LFN-DTA (green triangle) subunit. This receptor micro-clustering also induces the uptake of the whole complex by the cell inside of a vesicle. The vesicle’s lower pH promotes the insertion of the PA’ complex through the membrane forming a channel and delivering LFN-DTA into the cytosol. LFN-DTA causes cell death by ADP-ribosylation of a critical gene regulator (eEF2).

A. EGF-toxin was tested vs Mitomicyn C and Gemcitabine at different concentrations in human T24 cells. B. Experimental setup was conducted by binding EGF-PA’ at its LC100 concentration on ice and allowing complex assembly and internalization for different times before stripping off non-internalized protein and adding complete media. MTT assays were conducted 48h later. C. EGF-toxin induces bladder tumor reduction in dogs afflicted with spontaneous bladder cancer. Ultrasound images captured from a dog before (PRE, top 2 images) and after (POST, bottom 2 images) treatment with EGF-toxin. The 2 images on the left were made in the sagittal plane. The 2 images on the right were made in the transverse plane. The estimated tumor volume (sagittal area X transverse dorsal-ventral dimension) was 5.7 cm3 pre-treatment and 3.9 cm3 post treatment, yielding a 31% reduction in tumor volume after 1 single application.

Jack S, Madhivanan K, Ramadesikan S, Subramanian S, Edwards DF 2nd, Elzey BD, Dhawan D, McCluskey A, Kischuk EM, Loftis AR, Truex N, Santos M, Lu M, Rabideau A, Pentelute B, Collier J, Kaimakliotis H, Koch M, Ratliff TL, Knapp DW, Aguilar RC. (2020). A novel, safe, fast and efficient treatment for Her2-positive and negative bladder cancer utilizing an EGF-anthrax toxin chimera. Int J Cancer. Jan 15;146(2):449-460.