Abstract: Heat-inducible gene expression vectors are useful for hyperthermia-induced cancer gene therapy, because the combination
of hyperthermia and gene therapy can considerably improve the therapeutic effects. In the present study, we developed an enhanced
heat-inducible transgene expression system in which a heat-shock
protein (HSP) promoter and tetracycline-responsive transactivator
were combined. When the transactivator plasmid containing the
tetracycline-responsive transactivator gene was co-transfected with
the reporter gene expression plasmid, a high level of heat-induced gene expression was observed compared with that using the HSP
promoter without the transactivator. In vitro evaluation of the
therapeutic effect using HeLa cells showed that heat-induced therapeutic gene expression caused cell death in a high percentage of
these cells, indicating that this strategy is promising for cancer gene therapy.