-To modulate gene expression at transcription and translation levels by steric blocking of cellular machinery by means of irreversibly and specifically linked platinated oligonucleotides
-To elucidate the mechanism of the interstrand cross-linking reaction between the platinated oligonucleotides and their targets
-To achieve an automated synthesis of platinated oligonucleotides
To make transplatin-modified oligonucleotides efficient to sterically block the cellular machinery and thus to modulate specifically gene expresion, we take advantage of the participants'expertise in chemistry of platinum(II) complexes and oligonucleotides, physical-chemistry of platinated oligonucleotides, biochemistry and biology of cells. The oligonucleotides will be irreversibly and specifically cross-linked to their targets. The cross-linking reaction of the platinated oligonucleotides to their targets is triggered by the formation of the double or triple helices between the platinated oligonucleotides and their respective targets. Three main complementary research lines will be followed.-1). The rearrangement of trans-DDP-1,3-intrastrand cross-links into interstrand cross-links promoted by double helices will be tested in cells (trans-DDP is for trans-diamminedichloroplatinum(II)). The rearrangement of the trans-DDP-1,3-intrastrand cross-links promoted by the binding of the platinated oligonucleotides to duplexes with formation of triplexes, will be studied.-2). The pairing of an oligonucleotide containing a trans-DDP-monofunctional adduct with its complementary strand, results in the formation of an interstrand cross-link. We will study the interstrand cross-linking reaction in triplexes. This work, initially done with trans-DDP-monofunctional adduct, will be extended to other platinum(II) complexes.-3). The efficiency of each newly platinated oligonucleotide at blocking specifically gene expression, will be determined by biological assays incell-free and cell culture systems (cancer cells and virus infected cells).