STUDIES ON THE ANTUMOR ACTIVITY OF ORGANOTIN COMPOUNDS

Organotin compounds were found to obviously inhibit the activity of phospholipid/Ca²⁺-dependent protein kinase(PKC)in rat brain tissue and the proliferation of tumor cell lines in vitro．The results showed that a correlation exists between the effects on PKC and anti-proliferative and antitumor activities．The structure-activity relationship was shown to be as follows：(1)R，the organic group determines the biological activity；(2)electronegativity of the halogen can affect the activity．The organotin compounds inhibit tumor cells by itsSnR₂²⁺，and inhibit G₁→s phases of HL-60 cell cycle．The IC₅₀ ofSnPh₂F₂，SnPh₂(CysOS)·H₂O andSnPh₂CI₂·phen(CH₃)₂are respectively 25，15 and 20 umol·L^-1 on PKC，0．5，4．0 and 0.3 umol.L^-1 on HL-60 cells，2．7，9 and 1.5 umol·L^-1 on BEL-7402 cells，2．2，15 and 5.0 umol·L^-1 on KB cells．But no induction of differentiation of leukemic cell lines HL-60 and K562 Was observed．