Anticancer activity of organometallic compounds. 3. The reaction of dimethyltin dichloride with nucleosides under biologically relevant conditions

Synthesis, characterization and in vitro cytotoxicity of pentacoordinated Tin(IV) complexes derived from aminoalcohols

The synthesis of pentacoordinated Tin(IV) compounds derived from aminoalcohols is described. The compounds were characterized by IR, 1H-, 13C-, and 119Sn-NMR, the mass spectrometry exhibits molecular ions corresponding to monomeric species. All compounds were evaluated for in vitro cytotoxic activities against five human tumor cell lines, U251 (human glioblastoma), PC-3 (human prostatic adenocarcinoma), K-562 (human chronic myelogenous leukemia), HCT-15 (human colorectal adenocarcinoma), MCF-7 (human mammary adenocarcinoma). The cytotoxic evaluation revealed that all compounds possess higher cytotoxic potency than that of the cisplatin, which was used as reference. Additionally, MT2 cells (human T-lymphocytes) were also evaluated.

Cytotoxicity of tin on human peripheral lymphocytes in vitro

The comparative effects of inorganic and organic tin compounds on chromosomes were assessed in human peripheral blood lymphocytes of healthy donors 20-40 years of age. The endpoints observed were chromosomal abnormalities, sister-chromatid exchanges (SCEs) and cell cycle kinetics. The maximum concentrations which reduced the replicative index by about 50%, of stannic chloride and trimethyltin chloride were 40 micrograms and 2 micrograms per culture respectively. The tested doses were 20 micrograms and 10 micrograms of stannic chloride and 1 microgram and 0.5 microgram of trimethyltin chloride. Both doses of stannic chloride induced a much higher frequency of chromosomal abnormalities (P less than 0.05-P less than 0.001) and a greater reduction of cell cycle kinetics than the corresponding relative doses of trimethyltin chloride. The frequencies of SCEs/cell induced by the latter were, however, slightly higher than those induced by the former.

The interaction of native DNA with dimethyltin(IV) species

The reaction of aqueous native DNA (calf thymus) with the solvated organotin(IV) species [(CH3)2SnCl2(C2H5OH)n], as well as with [(CH3)2Sn(OH)(H2O)n]+ and (CH3)2Sn(OH)2 (i.e., the hydrolysis products of aqueous (CH3)2SnCl2 at pH approximately 5 and pH approximately 7.4 respectively), was investigated by 119Sn Mössbauer spectroscopy. The addition of [(CH3)2SnCl2(C2H5OH)n] to DNA yielded a solid product, possibly (CH3)2Sn(DNA phosphodiester)2, where the environment of the tin atom is trans-octahedral with linear CSnC skeleton, and the equatorial atoms may consist of oxygen or nitrogen from water as well as from the nucleic acid constituents. No interaction with DNA apparently takes place due to hydrolyzed dimethyltin(IV) species, which occur in aqueous phases at approximate physiological pH values. The reaction pathway is then assumed to require weakly solvated, easily dissociable species such as [(CH3)2SnCl2(C2H5OH)n], which would imply in vivo reactivity of cellular DNA with organotins from hydrophobic sites.

Diorganotin dihalide complexes of 2,2'-biimidazole. A preliminary study of their inhibitory effects on cell division

We report the synthesis of new complexes with the general formula (R2SnX2)y.H2BiIm, where y = 1 or 2; R = Me, Et, Bun; X = Cl or Br (for R = Et) and H2BiIm = 2,2'-Biimidazole. The complexes have been characterized by elemental analysis and Mössbauer, infra-red and 1H n.m.r. spectroscopy and tested (like the ligand, Me2SnCl2 and Et2SnCl2) against P388D1 leukemic cells.

Cytotoxic effects of trimethyltin chloride on human peripheral blood lymphocytes in vitro

Trimethyltin chloride was found to induce cytotoxic damage in vitro in human peripheral blood lymphocytes. Two concentrations (0.5 micrograms and 1.0 micrograms) were added to lymphocytes from male and female subjects in mitogen stimulated and serum supplemented culture medium for 72 h. A dose-related increase of inhibition of replication index (P less than 0.01) and cell division (P less than 0.001) was observed. The frequencies of abnormal cells and chromosomal aberrations such as chromatid and chromosome breaks, dicentrics, triradial and quadriradial configurations were increased significantly (P less than 0.001), as were micronucleus counts (P less than 0.001) and sister chromatid exchanges (P less than 0.001). Endoreduplication, an extremely rare spontaneous event in human lymphocytes, was observed in a few cases at all dose levels. The effects were more pronounced in lymphocytes obtained from habitual smokers.