In vitro cytotoxic activity of tri-n-butyltin(IV)lupinylsulfide hydrogen fumarate (IST-FS 35) and preliminary antitumor activity in vivo.

The cytotoxicity in vitro and antitumor activity in vivo of the organotin compound tri-n-butyltin(IV)lupinylsulfide hydrogen fumarate (IST-FS 35) have been investigated. The IC50 values obtained in a panel of tumor cell lines were compared to those of the parental compound IST-FS 29 in the same cells. IST-FS 35 resulted significantly more active than IST-FS 29 with IC50 values in the range 0.16-1.8 microM. Toxicity studies in vivo, after intravenous administration of escalating concentrations of IST-FS 35, provided the identification of the maximal tolerated dose (3.5 mg/kg) which was employed as therapeutic dose in the antitumor activity experiments. Preliminary results, in transplanted murine tumor models, revealed that both the P388 myelomonocytic leukaemia and the B16-F10 melanoma, implanted subcutaneously in BDF1 mice, were inhibited about 96% in their tumor volume at day 11, following a single intravenous injection of the compound. Additional studies are mandatory to unravel the mechanism of action for the development of IST-FS 35 as potential antitumor drug.

Resonance ionization spectroscopy for multiplex sequencing of tin-labeled DNA.

A method is described for synthesis of a tin reagent, triethylstannylpropanoic acid (TESPA), and its attachment to oligonucleotide primers. Except for the expected mobility retardation, the presence of [116Sn]-TESPA did not affect the sequencing ladder on electrophoresis gels. By using [120Sn]-TESPA and [35S]-dTTP simultaneously in the Sanger procedure, DNA bands on an electrophoresis gel were first located by autoradiography and then by resonance ionization spectroscopy to demonstrate the coincidence of the signals. Previous results using stable isotopes as labels on model compounds are now confirmed by their use in actual DNA sequencing products.