cellular engineering presentation - milap thaker, matthew lawler et al

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Eradication of Solid Tumor via Gancyclovir-based Activation of VP22-tk Toxicity and Liposomal Toxin Delivery. Cellular Engineering, Kevin Parker, Professor

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Eradication of Solid Tumor via Gancyclovir-based Activation of VP22-tk Toxicity and Liposomal Toxin Delivery :

Eradication of Solid Tumor via Gancyclovir -based Activation of VP22-tk Toxicity and Liposomal Toxin Delivery Cellular Engineering - K. Parker, Professor Lawler, M. • Cartwright, W. • Thaker , M.

Relevance:

Relevance Prevalence and Challenges native to Breast Cancer Second most prevalent form of cancer amongst females Resistance to treatment Increased Metastatic Potential/Tumor Growth due to Autocrine Signaling Autocrine Signaling  Increased Angiogenesis

Overview:

Overview Autocrine Signal Manipulation (Prolactin) CE Pluripotency Manipulation Engineered to contain Suicide Gene under control of Chimeric Prolactin Receptor Cells will also contain Toxin-Loaded Microcapsules

Expected Benefits:

Expected Benefits Combination of Suicide Gene/Prolactin Trigger will allow for Selective Cytotoxicity Spares non-cancerous Angiogenic Regions Localized Microcapsular Toxin Delivery leads to site-specific Chemotherapeutic Agent delivery

Specific Pathways of Exploitation - 1:

Specific Pathways of Exploitation - 1 Prolactin Strong Association b/w High Serum Prolactin Levels and Rapid Mammary Tumor Growth Role of Dopamine Agonists Shortcomings of Rodent Model vs. Human Model

Specific Pathways of Exploitation - 2:

Specific Pathways of Exploitation - 2 Angiogenesis Exploitation Use of Modified Capillary Endothelial Progenitor Cells Cultured to encourage differentiation into CE cells Modifications In Vitro Suicide Gene Conversion of Prodrug  Toxic Compound

Prodrug  Toxic Compound Pathway:

Prodrug  Toxic Compound Pathway Neither Enzyme in SG nor Prodrug Toxic Individually Cytotoxicity only present when cells expressing gene + prodrug Gancyclovir HSV-1 TK Analog Image 1: http://www.bmb.leeds.ac.uk/mbiology/ug/ugteach/icu8/antibiotics/antivirals.html Image 2: http://www.strubi.ox.ac.uk/strubi/research/DKSgroup/vzk2.html

Mechanisms of Destruction:

Mechanisms of Destruction 2 Effects of Toxic Product at Tumor Sites: Death of Modified CE Cells “Bystander Effect” Tumor Mass Decreased via: Direct Toxic Killing of Tumor Cells Nutrient Starvation Resulting from Breakdown of Tumor Vasculature

Limitations of Current Therapies:

Limitations of Current Therapies Percentage of modified cells which differentiate into CE not high enough. Modified Cells = only small % of total CE cells Does not differentiate between Cancerous/non-Cancerous Regions Cannot be used post-op/chronic sores/ulcers Modified Cells could lodge anywhere Toxicity-induced Inflammation/Vascular Failure

Mechanism of Destruction - Targeted Microcapsular Delivery:

Mechanism of Destruction - Targeted Microcapsular Delivery Architecture of Microcapsule Lipid Based Outer Coating Core of Toxic Chemicals Small Enough to be Endocytosed by Cells Disruption Mechanisms Heat Light Ultrasound

Microcapsular Size:

Microcapsular Size Counterclockwise from upper-left: Engulfing of beads under 1 micron in diameter (fig 1 & 2) Chen, Geometric Control of Cell Life and Death - 10 micron beads engulfed w/normal function, no elevated apopototic activity

Therapy Outline - I:

Therapy Outline - I

Therapy Outline - 2:

Therapy Outline - 2

Therapy Outline - 3:

Therapy Outline - 3

Therapy Outline - 4:

Therapy Outline - 4

Therapy Outline - 5:

Therapy Outline - 5

Therapy Outline - 6:

Therapy Outline - 6

Therapy Outline - 7:

Therapy Outline - 7

Emergency Extraction Plan:

Emergency Extraction Plan Toxicity Mediated Sepsis Stop administration of ganciclovir and the ultrasound microcapsule activation Loss of Control over Modified Cells Teratoma? Cease Administration of Dopamine Agonist Continue Ganciclovir Administration

Potential Drawbacks of Approach:

Potential Drawbacks of Approach Contingent upon Tumor Engaging in Active Angiogenesis Tumor Cells Halt Autocrine/Paracrine Prolactin Signaling Side Effects of CE-Injection Proliferative Diabetic Retinopathy Pre-existing Capillary Proliferation-Related Conditions not eligible for treatment

Benefits of Proposed Approach:

Benefits of Proposed Approach Specific Targeting of Tumor Regions Spares other tissues Allows for very strong agents with limited side effects Microcapsules Allows use of chemotherapeutic agents that are highly effective, but difficult to administer via other means

Benefits - 2:

Benefits - 2 Destruction of Tumor Vasculature/Nutrient Supply as well as Neoplastic Cells Can destroy small, intravasated metastases previously undetected Maintenance of Remission Does not rely on delivery of transgenes to tumors in vivo

Benefits - 3:

Benefits - 3 Ex Vivo - Transgenes delivered only to desired cells Transgenic Cassette maintained in dipolid cells with intact DNA - decreases likelihood of transgenes being lost/altered. No reliance on viral vector Relies heavily on materials derived from patient (lipids, cells, etc.)