Description:
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.
References
iGEM 2007
http://parts.mit.edu/igem07/index.php/Princeton
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
tzodikov@princeton.edu