Feasibility of a predictive model of Hsp70b-activated gene therapy protein expression during ultrasound hyperthermia

Gene therapy has been heralded as a possible approach to a variety of diseases and conditions, ranging from cancer and heart disease to blindness and neurodegenerative diseases. However, progress in gene therapy requires a delivery system that can control when and where the therapeutic proteins will be generated. Our study was performed to determine the feasibility of attaching heat-inducible promoters to genes of interest in order to control activation of the gene in vivo via ultrasound-induced hyperthermia monitored by MRI thermometry. We first demonstrated that gene therapy-mediated gene expression could be spatially and temporally controlled with this method. Further studies were subsequently performed to determine if the activation of a particular heat-inducible gene, Hsp70b, could be quantified and predicted a priori during hyperthermia, thus allowing advance knowledge of the protein levels over time. Experiments indicated that as the temperature and duration of a hyperthermic shock increased, peak expression levels of Hsp70b mRNA also increased until a saturation level was reached. In addition, as the duration of a hyperthermic shock increased, the time during which Hsp70b mRNA remained elevated also increased. Most significantly, a correlation was found between total Hsp70b mRNA production generated by thermal shock and thermal dose, a predictor of dose often used in hyperthermia therapies. The relationship found between total Hsp70b mRNA production and thermal dose suggests that a real-time predictive model of therapeutic protein dose kinetics after ultrasound-induced hyperthermia for gene therapy is feasible. However, the creation of such a model would require further precision experimentation for which ultrasonically-induced hyperthermia is not suited. A final study was performed and found that Hsp70b was not activated by the mechanical stress caused by ultrasound. These results confirm that a predictive model applicable to ultrasonically-induced hyperthermia could be developed using waterbath techniques that will allow tighter control of temperature.

Department dc:contributor.department

Harvard--MIT Program in Health Sciences and Technology.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2014

Author dc:creator

• Silcox, Christina Elise

Advisor dc:contributor.advisor

• Stuart K. Calderwood.

• Harvard--MIT Program in Health Sciences and Technology.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/90174

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/90174