Metallothionneis are low-molecular proteins, which are taking part on supervision of metal homeostasis.About molecular mechanisms of MT expression it is known too little and probably single metal is participating in MT expression by bonding on transcriptional factor MTF-1. Recently researches denote at important relations between MT concentration and carcinogenesis, mutagenesis and teratogens. MT is known as prognostic marker at many kinds of cancer and it is negatively related to anticancer drugs. For example cisplatine is used more than 40 years and is engages to quanine in DNA molecule. However cell can recognise a formed adducts and by correcting mechanisms aspires to repair it. Rising of metal concentration in organism leads to increasing MT expression and subsequently therapeutic effect is markedly reduced. Using of antisense mRNA, genes therapy, protease and application of another metals is an option how we can defend organisms to prevent of these undersirable effects. Necessary condition of study of behaviour biological molecules are well applied analytical methods. Methods using for MT determination are beside electrophoresis and chromatography also electrochemistry or mass spectrometry.

        Key words: metallothionein, cisplatine, carcinogenesis, gene therapy, heavy metals, analysis of MT.