- Hyperthermia + Radiotherapy
- Hyperthermia + Chemotherapy
- Hyperthermia + Radiochemotherapy
- The Future
Thermosensitive liposomes: selectively targeting drugs to tumours by hyperthermia
A very interesting topic to be developed is the effect of hyperthermia in selectively targeting drugs to tumors. Many attempts have been made to reduce systemic toxicity of anticancer treatments, using antibodies, viral vectors and drug carriers. One of the most important limit to these attempts is that carriers cannot efficiently cross the vascular wall.
Temperature sensitive liposomes (Kawai et al., 2005; Ahmed et al., 2004; Di Filippo et al., 2004; Kong et al., 2001), magneto liposomes (Lindner 2004; Matsuoka et al., 2004; Shinkai et al., 2001) could introduce interesting improvements as tumor blood flow and nanoparticles extravasion are selectively enhanced by mild (40�C to 42�C) hyperthermia (Kong et al., 2001).
Elastin-like polypeptides have been also investigated to provide a new way to thermally target polymer-drug conjugates to solid tumors (Meyer et al., 2001). A recent study (Hauck et al., 2005) also shows enhanced tumor uptake of radiolabelled anti-tenascin chimeric mAb, that is also a very interesting result concerning selective targeting of drugs through highly specific antibodies.
Heat Shock Proteins (HSPs) are another of science's very interesting frontiers in this field. Beside protecting cells from apoptosis, HSP 70, HSP 90 and glucose regulated protein-96 showed a pivotal role in immune reactions.
Their role on tumor immunogenicity is the object of ongoing studies (Srivastava et al., 2005; Ito et al., 2001; Castelli et al., 2001).
In a study comparing radiotherapy to radiotherapy plus hyperthermia in cervical cancer, the percentage of patients developing metastatic disease was significantly lower in the combined treated group than that in radiotherapically treated alone, which could be related to a HSPs induced tumor immunogenicity (Van der Zee et al., 2002).
Moreover HSPs seem to affect some expression of those genes that are regulated by heat shock promoters. This could give new chances to gene therapy (Lohr et al., 2000; Huang et al., 2000).