Biological evaluation of dodecaborate-containing L-amino acids for boron neutron capture therapy.
ABSTRACT To develop a boron carrier for practical purposes, new boron-containing amino acids with an undecahydro-closo-dodecaboranylthio ([(10)B(12)H(11)S](2-)-) unit in the side chain of the α-amino acid have already been designed and synthesized. In the present paper, cytotoxicity, the incorporation amounts into tumor cells, and the tumor cell killing effects of these compounds were elucidated to evaluate their usefulness as boron carriers. Furthermore, the microdistribution of the amino acids in tumor cells was established.
- SourceAvailable from: Silvya Stuchi Maria-Engler[show abstract] [hide abstract]
ABSTRACT: Boron neutron capture therapy (BNCT) is a binary treatment involving selective accumulation of boron carriers in a tumor followed by irradiation with a thermal or epithermal neutron beam. The neutron capture reaction with a boron-10 nucleus yields high linear energy transfer (LET) particles, alpha and (7)Li, with a range of 5 to 9 µm. These particles can only travel very short distances and release their damaging energy directly into the cells containing the boron compound. We aimed to evaluate proliferation, apoptosis and extracellular matrix (ECM) modifications of B16F10 melanoma and normal human melanocytes after BNCT. The amounts of soluble collagen and Hsp47, indicating collagen synthesis in the ECM, as well as the cellular markers of apoptosis, were investigated. BNCT decreased proliferation, altered the ECM by decreasing collagen synthesis and induced apoptosis by regulating Bcl-2/Bax in melanoma. Additionally, BNCT also increased the levels of TNF receptor and the cleaved caspases 3, 7, 8 and 9 in melanoma. These results suggest that multiple pathways related to cell death and cell cycle arrest are involved in the treatment of melanoma by BNCT.PLoS ONE 01/2013; 8(3):e59639. · 3.73 Impact Factor