Synthesis and characterization of Pd(II) and Pt(II) complexes of p-isopropylbenzaldehyde N-protected thiosemicarbazones.: Cytotoxic activity against ras-transformed cells

Cytotoxicity tests in tumor cells sensitive to cis-DDP (HL-60, JURKAT,Hela and 3T3) and in tumor cells transformed by ras oncogenes and resistant to cis-DDP (Pam 212-ras) show that cyclometallated complexes 1a [Pd(p-is.TSCN-NHMe) ](4,) 2b [Pt(p-is.TSCN-NMe2)](4) and 4a [Pd(p-is.TSCN-NHex) ](4) may be endowed with specific cytotoxic properties. In fact, these three novel metal-thiosemicarbazone compounds kill Pam 212-ras cells through apoptosis induction. These results. together with others recently published, indicate that the design and synthesis of metallated-thiosemicarbazone compounds may lead to the discovery of novel antitumor agents able to circumvent cis-DDP resistance, in particular tumor cell lines. (C) 1999 Elsevier Science Inc. All rights reserved.