Detection and Destruction of Cancer Cells Using Programmed Genetic Vectors

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Princeton University Invention # 08-2468


Current cancer treatments (e.g. chemotherapy or radiation therapy) utilize highly non-specific approaches to killing cancerous cells.  Such methods are not able to specifically target a particular type of cancer cell and, although these treatments kill cancer cells, they also inflict a great deal of collateral damage on healthy cells.  In addition, multiple treatments are typically necessary in order to place a patient in `remission¿.  The harmful side effects from repeated assaults on the body by deadly chemicals or radiation is highly undesirable. 


In response to the need for highly targeted detection and destruction of cancerous cells, Researchers in the Department of Electrical Engineering, Princeton University have developed an   approach which implements a synthetic RNAi-enhanced genetic logic circuit in mammalian cells which identifies multiple markers of a specific cancer and selectively destroys the cancerous cells, leaving other cells to grow normally.  The proposed synthetic RNAi circuit is capable of deciphering the cellular transcriptome, calculating levels of targeted biomarkers and determining that cells are either healthy or cancerous by evaluating internal cell state through mRNA expression patterns.  The overall decision on whether to destroy the cell or not is performed using a logic formula implemented with the biochemical mechanism of RNAi ¿ these logic formulas can theoretically detect any logical pattern of mRNA levels using combinations of AND and OR logic operations.


A prototype implementation is currently based on the evaluation of one input using the MCF-7 cell line.  In the case of a healthy cell where GATA3 is present in small quantities, translation of the pro-apoptotic factor Bax is repressed by the binding of designed small interfering RNA (siRNA) to the engineered sequences located either 5' or 3' to the apoptosis-inducing gene. In the case of MCF-7 cells when GATA3 is present above a certain set threshold, GATA3 mRNA will titrate away the designed siRNA and allow translation of the apoptosis inducing gene Bax. The siRNA is designed with base pair mismatches to the GATA3 sequence in specific regions so that it does not induce the RNAi machinery of the cell and will not degrade the GATA3 mRNA. 


We have experimentally demonstrated the efficiency of the Bax apoptosis inducing gene.  Induction of Bax over-expression led to cell death within 24 hours.  Furthermore, we have constructed a non-integrating lentivirus based on work by Nightingale et al. (2006).  A non-integrating lentivirus eliminates the possibility of pseudorandom integration that could itself lead to cancer.  Moreover, infection using a non-integrating lentivirus prevents actual modification of the host¿s genome that would propagate indefinitely through cell divisions.   Results show GFP levels diminishing over 7 days after infection with the non-integrating lentivirus.


Further work is ongoing to pursue and test a fully functional system.


Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity. Patent protection is pending.



iGEM 2007



For more information on Princeton University invention # 08-2468:


                        Laurie Tzodikov

                        Office of Technology Licensing and Intellectual Property

                        Princeton University

                        4 New South Building

                        Princeton, NJ 08544-0036

                        (609) 258-7256

                        (609) 258-1159 fax


Patent Information:
For Information, Contact:
Laurie Tzodikov
Licensing Associates
Princeton University
Ronald Weiss
Priscilla Purnick
Caroline Dehart
Jon Monk
Aparna Swaminathan