[Neurotrophins and their receptors in tumors].

Neurotrophins are structurally related growth polypeptide factors that play an essential role in the development and functioning of the vertebrate nervous system. They provide forming and survival of different neuron populations of the central and peripheral nervous system. Neurotrophins are also involved in the processes of higher nervous activity. Neurotrophins are active not only in the nervous system; these universal trophic factors are important for the development, proliferation, and maintaining of different tissues including tumor tissues. Changes in the neurotrophin signaling system are significant for the pathogenesis of malignancies at the initiation stage as well as during the tumor progression. Neurotrophins and their receptors are complex multi-component system controlled in a very complicated manner. This system can affect the cells and tissues in different ways; the final results of neurotrophin action vary from cell maintenance and survival to apoptosis. Differences in mechanisms and results of the neurotrophin action depend on the cell and tissue type in which the system works. The effects of the neurotrophin signaling are especially variable in different malignancies. In the review we summarize the information on the neurotrophin signaling in various tumors and demonstrate its contribution to the disease course.

[Structural and functional analyses of the Hfb1, Hmob3 and Hmob33 cDNAs as an example of human brain-specific gene studies]. / Strukturno-funktsional'nyi analiz kDNK-posledovatel'nostei Hfb1, Hmob3 i Hmob33 kak primer issledovaniia mozgospetsificheskikh genov cheloveka.

Brain-specific human genes were studied over the recent years in the Department of Molecular Bases of Human Genetics, Institute of Molecular Genetics. Clones Hfb1, Hmob3, and Hmob33 were selected from human brain cDNA libraries by differential screening. The clones were sequenced, mapped, and tested for expression in various human tissues. In vitro and in silico experiments identified Hfb1 as an earlier unknown complexin 2 gene (CPLX2) fragment, which codes for the large 3'-untranslated region of the CPLX2 mRNA. Hmob3 proved to correspond to an earlier unknown fragment of the large 3'-untranslated region of the human MAP1B mRNA. With Hfb1 and Hmob3, new terminal exons were revealed and exact structures established for CPLX2 and MAP1B. Hmob33 was identified as a fragment of the 3'-terminal exon of a new gene, MOB, which codes for a thus far unknown evolutionarily conserved transmembrane protein. The structure of the deduced protein product was analyzed.

[Brain-specific sequence Hfb1 is part of the 3'-untranslated region of the human complexin 2 gene: new data from in vitro and in silico experiments]. / Mozgospetsificheskaia posledovatel'nost' Hfb1 vkhodit v sostav protiazhennoi 3'-netransliruemoi oblasti gena komplksina 2 cheloveka: novye dannye in vitro i in silico éksperimentov.

A genomic clone hybridizing with brain-specific sequence Hfb1 was isolated from a chromosome 5 consmid library. Hfb1 proved to correspond to a new gene exon which codes for a large 3'-untranslated region of the mRNA for synaptic protein complexin 2. Together with the 985-nt Hfb1 cDNA (EMBL Y15167) isolated previously from a cDNA library of the frontal cerebral cortex, the primary structure was established for genomic clone Ghfb sized more than 4 kb. A GenBank search revealed complete identity of the 5' end of Ghfb and the 3'-untranslated region (878-933) of the human complexin 2 mRNA. Large transcripts with the 5' end corresponding to the complexin 2 mRNA and the 3' end to Ghfb were detected in total mRNA of the human brain by means of RT-PCR. The size of the 3'-untranslated region of the human complexin 2 mRNA was estimated at 4 kb.