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The possibility of blocking the expression of selected genes raises great hopes for the treatment of incurable diseases so far , such as neurodegenerative diseases , autoimmune diseases and cancer . The RNA molecule due to its biochemical properties of a promising therapeutic tool . The discovery of RNA interference (RNAi ) started the new tests for inhibition of expression of selected genes by small interfering RNA ( siRNA) in mammalian cells. This technique uses a natural process of gene silencing the expression of double-stranded RNA -dependent . Ribonuclease RNase III activity in human cells called Dicer , degrades double-stranded , linear RNA into siRNA fragments . This is followed by formation of the complex called RISC rybonukleinoproteinowego . RISC complex has helicase activity , as well as endo- and exonucleases . The antisense strand of siRNA located within the RISC recognizes the complementary sequences within the mRNA. This is followed by endonucleolytic degradation of mRNA in the region complementary to the antisense strand of siRNA. Blocking the expression of selected genes by RNA interference can be achieved by introducing into mammalian cells chemically synthesized or obtained by in vitro transcription of RNA segments corresponding to the siRNA sequence . It is also possible siRNA in vivo synthesis of the templated vector under the control of the U6 or H1 RNA polymerase III (Pol III) . Engineered sequences may be of the split loop palindromes . These sequences form a hairpin structure ( shRNAs ) that are recognized by the enzyme Dicer into siRNA and degraded . Many of the features described RNAi , especially selektywość substrate raises high hopes to use it not only for basic research. For RNAi phenomenon found use in medicine , it must be clarified biochemical basis which will allow to achieve a clear understanding of the choice of target sequences for siRNA.

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The Editorial Board
Andrzej Łukaszyk - przewodniczący, Zofia Bielańska-Osuchowska, Szczepan Biliński, Mieczysław Chorąży, Aleksander Koj, Włodzimierz Korochoda, Leszek Kuźnicki, Aleksandra Stojałowska, Lech Wojtczak

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Katedra i Zakład Histologii i Embriologii Uniwersytetu Medycznego w Poznaniu, ul. Święcickiego 6, 60-781 Poznań, tel. +48 61 8546453, fax. +48 61 8546440, email:

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