Specific Cytotoxicity of Targeted 177Lu and 212Pb-Based Radiopharmaceuticals.

Two radiopharmaceutical preparations were developed on the basis of artificial targeted polypeptide ZHER2 specific to HER2/neu tumor marker and radionuclides 177Lu (ZHER2-HSA-chelator-177Lu) or 212Pb (ZHER2-HSA-chelator-212Pb). The objective was to evaluate in vitro the cytotoxic activity of the targeted radiopharmaceuticals using two cultured human breast cancer cell lines with different expression of HER2/neu: SK-BR3 (high expression of HER2/neu) and MCF-7 (low expression of HER2/neu). It was shown that the cytotoxic effect of both preparations was significantly higher against the SK-BR-3 cells. The cytotoxicity correlated with the incubation period (it was higher after 72 h than after 24 h) and was significantly more pronounced in comparison with activity of radionuclide salts without a specific ligand. In vivo preclinical study of these pharmaceuticals seems to be very promising in animals with xenografted tumors showing high expression of HER2/neu marker.

[Targeted Bifunctional Proteins and Hybrid Nanoconstructs for Cancer Diagnostics and Therapies].

In this review, the authors' works published within the past 5 years devoted to the development of bifunctional hybrid nanostructures based on the targeting polypeptides and nanoparticles of various origin (quantum dots, nanogold, nanodiamonds, upconversion nanoparticles, magnetic and polymer nanoparticles) as modules that ensure visualization and various damaging effects on cancer cells are surveyed and the prospects of their application in theranostics and precision medicine have been contemplated.

[Supramolecular Agents for Theranostics].

This mini-review summarizes recent data obtained in the process of creation of a versatile module platform suitable for construction of supramolecular theranostic agents. As an example, we consider multifunctional hybrid agents for imaging and elimination of cancer cells. The use of an adapter protein system barnase:barstar for producing targeted multifunctional hybrid structures on the basis of highly specific peptides and mini-antibodies as addressing modules and recombinant proteins and/or nanoparticles of different nature (quantum dots, nanogold, magnetic nanoparticles, nanodiamonds, upconverting nanophosphores, polymer nanoparticles) as agents visualizing and damaging cancer cells is described. New perspectives for creation of selective and highly effective compounds for theranostics and personified medicine are contemplated.

ERBB oncogene proteins as targets for monoclonal antibodies.

General properties of the family of tyrosine kinase ERBB receptors are considered in connection with their role in the generation of cascades of signal transduction in normal and tumor cells. Causes of acquisition of oncogene features by genes encoding these receptors and their role in tumorigenesis are analyzed. Anti-ERBB monoclonal antibodies approved for therapy are described in detail, and mechanisms of their antitumor activity and development of resistance to them are reviewed. The existing and the most promising strategies for creating and using monoclonal antibodies and their derivatives for therapy of cancer are discussed.

Near-Infrared Activated Cyanine Dyes As Agents for Photothermal Therapy and Diagnosis of Tumors.

Today, it has become apparent that innovative treatment methods, including those involving simultaneous diagnosis and therapy, are particularly in demand in modern cancer medicine. The development of nanomedicine offers new ways of increasing the therapeutic index and minimizing side effects. The development of photoactivatable dyes that are effectively absorbed in the first transparency window of biological tissues (700-900 nm) and are capable of fluorescence and heat generation has led to the emergence of phototheranostics, an approach that combines the bioimaging of deep tumors and metastases and their photothermal treatment. The creation of near-infrared (NIR) light-activated agents for sensitive fluorescence bioimaging and phototherapy is a priority in phototheranostics, because the excitation of drugs and/or diagnostic substances in the near-infrared region exhibits advantages such as deep penetration into tissues and a weak baseline level of autofluorescence. In this review, we focus on NIR-excited dyes and discuss prospects for their application in photothermal therapy and the diagnosis of cancer. Particular attention is focused on the consideration of new multifunctional nanoplatforms for phototheranostics which allow one to achieve a synergistic effect in combinatorial photothermal, photodynamic, and/or chemotherapy, with simultaneous fluorescence, acoustic, and/or magnetic resonance imaging.

Functional conservation of RNA polymerase II in fission and budding yeasts.

The complementary DNAs of the 12 subunits of fission yeast (Schizosaccharomyces pombe) RNA polymerase II were expressed from strong promoters in Saccharomyces cerevisiae and tested for heterospecific complementation by monitoring their ability to replace in vivo the null mutants of the corresponding host genes. Rpb1 and Rpb2, the two largest subunits and Rpb8, a small subunit shared by all three polymerases, failed to support growth in S. cerevisiae. The remaining nine subunits were all proficient for heterospecific complementation and led in most cases to a wild-type level of growth. The two alpha-like subunits (Rpb3 and Rpb11), however, did not support growth at high (37 degrees C) or low (25 degrees C) temperatures. In the case of Rpb3, growth was restored by increasing the gene dosage of the host Rpb11 or Rpb10 subunits, confirming previous evidence of a close genetic interaction between these three subunits.

Internalization and Recycling of the HER2 Receptor on Human Breast Adenocarcinoma Cells Treated with Targeted Phototoxic Protein DARPinminiSOG.

Design and evaluation of new high-affinity protein compounds that can selectively and efficiently destroy human cancer cells are a priority research area in biomedicine. In this study we report on the ability of the recombinant phototoxic protein DARPin-miniSOG to interact with breast adenacarcinoma human cells overexpressing the extracellular domain of human epidermal growth factor receptor 2 (HER2). It was found that the targeted phototoxin DARPin-miniSOG specifically binds to the HER2 with following internalization and slow recycling back to the cell membrane. An insight into the role of DARPin-miniSOG in HER2 internalization could contribute to the treatment of HER2-positive cancer using this phototoxic protein.

A high-level prokaryotic expression system: synthesis of human interleukin 1 alpha and its receptor antagonist.

Synthetic intronless genes, coding for human interleukin 1 alpha (IL 1 alpha) and interleukin 1 receptor antagonist (IL1ra), have been expressed efficiently in a specially designed prokaryotic vector, pGMCE (a pGEM1 derivative), where the target gene forms the second part of a two-cistron system. The first part of the system is a translation enhancer-containing mini-cistron, whose termination codon overlaps the start codon of the target gene. In the case of the IL1 alpha gene, the high expression level is largely due to the direct efficient translation initiation at the second cistron, whereas with the IL1ra gene in the same system, the proximal translation initiation region (TIR) provides a high level of coupled expression of the target gene. Thus, pGMCE is a potentially versatile vector for direct prokaryotic expression.

[The first member of a novel family of eukaryotic transcription factors detected by the heterospecific complementation]. / Pervyi predstavitel' novogo semeistva éukarioticheskikh faktorov transkriptsii, obnaruzhennyi s pomoshch'iu mezhvidovoi komplementatsii.

The cDNA of a previously uncharacterized gene fet5 (factor of eukaryotic transcription, clone no. 5) of the fission yeast Schizosaccharomyces pombe was cloned by the heterospecific complementation of a conditional mutant of Saccharomyces cerevisiae defective in the function of the RNA polymerases I-III common subunit ABC10 beta. The gene encodes a new factor of eukaryotic transcription, Fet5, the first member of a superfamily of proteins for which the area of functioning is determined. The Fet5-superfamily consists of three distinct families of proteins highly evolutionarily conserved and widely spread among eukaryotes. Features of the Fet5 amino acid sequence suggest that it belongs to ATP/GTP-binding proteins.

[Molecular cloning and characterization of cDNA of the rpc10+ gene encoding the smallest subunit of nuclear RNA polymerases of Schizosaccharomyces pombe]. / Molekuliarnoe klonirovanie i kharakteristika kDNK gena rpc10+, kodirue shchego samuiu maluiu cyb''edinitsu iadernykh rnk-polimeraz Schizosaccharomyces pombe.

The full-length cDNA of the rpc10+ gene encoding mini-subunit Rpc10, which is common for all three nuclear RNA polymerases of the fission yeast Schizosaccharomyces pombe, was cloned and sequenced. The Rpc10 subunit of Sz. pombe and its homologs from S. cerevisiae and H. sapiens are positively charged proteins with a highly conserved C-terminal region and an invariant zinc-binding domain (Zn-finger) of a typical amino acid composition: YxCx2Cx12RCx2CGxR. Functional tests of heterospecific complementation, using tetrad analysis or plasmid shuffling, showed that the Rpc10 subunit of Sz. pombe can successfully replace the homologous ABC10 alpha subunit in nuclear RNA polymerases I-III of S. cerevisiae.

[Molecular identification and characteristics of hRPC11, the smallest specific subunit of human RNA polymerase III]. / Molekuliarnaia identifikatsiia i kharakteristika hRPC11, samoi maloi spetsificheskoi sub''edinitsy RNK-polimerazy III cheloveka.

Full-length copies of cDNA of the hRPC11 gene encoding the smallest specific subunit of nuclear RNA polymerase III were identified among human transcripts with the use of the RT-PCR technique. The cloning of the first orthologue of the subunit RPC11 from a multicellular organism and the comparison of subunit hRPC11 of Homo sapiens (108 aa; M(r), 12.3 kDa; pI 8.05) deduced from the cDNA primary structure with the homologous components of RNA polymerase III from Saccharomyces cerevisiae and Schizosaccharomyces pombe revealed the most important functional domains: a Zn-binding motif of the classic type (CxxCx16-17CxxC) at the N-terminal region, and two extended regions of homology (KEVDDVLGG and RSADEPM) in the central and C-terminal parts of the molecule, respectively. The C-terminus of the RPC11 subunits is highly homologous to the unique zinc ribbon of the elongation factor TFIIS, which suggests a role for this subunit in the elongation or termination of RNA synthesis.

[Exon-intron structure of the fet5+ gene of Schizosaccharomyces pombe and physical mapping of genome encompassing regions]. / Ekzon-intronnaia struktura gena fet5+ Schizosaccharomyces pombe i fizicheskoe kartirovanie okaimliaiushchikh ego uchastkov genoma.

Plasmid pYUK3 bearing the fet5+ gene of Schizosaccharomyces pombe was isolated from a genomic library of the fission yeast, and a detailed physical map of the whole genomic insert (ca. 9.6 Kbp) was constructed. The primary structure of the fet5+ gene and its flanking regions is established. The gene contains a single 45-bp intron in its distal part. A typical TATA-box (TATAAG) was found in the 5'-noncoding region ca. 50 bp upstream of the putative start of transcription, and the 3'-noncoding region contains AT-rich palindromes, which are probably involved in termination of the fet5+ transcription. A previously unidentified gene of Sz. pombe encoding a protein with some similarity to one of the transcriptional activators from the TBP (TATA-binding protein) group of SPT factors of transcription was found in the vicinity of the fet5+ gene. Taking into account that cDNA of the fet5(+)-gene was isolated as a suppressor of the genetic-defect of nuclear RNA polymerases I-III (Bioorg. Khim., 1997, vol. 23, No 3, pp. 234-237), this vicinity may be the first evidence of possible clustering, in the genome of the fission yeast, of genes participating in transcription regulation.

[Three regions of Rpb10 mini-subunit of nuclear RNA polymerases are strictly conserved in all eukaryotes]. / Tri oblasti mini-sub''edinitsy Rpb10 iadernykh RNK-polimeraz strogo konservativny u vsekh éukariot.

The rpb10+ cDNA from the fission yeast Schizosaccharomyces pombe was cloned using two independent approaches (PCR and genetic suppression). The cloned cDNA encoded the Rpb10 subunit common for all three RNA polymerases. Comparison of the deduced amino acid sequence of the Sz. pombe Rbp10 subunit (71 amino acid residues) with those of the homologous subunits of RNA polymerases I, II, and III from Saccharomyces cerevisiae and Home sapiens revealed that heptapeptides RCFT/SCGK (residues 6-12), RYCCRRM (residues 43-49), and HVDLIEK (residues 53-59) were evolutionarily the most conserved structural motifs of these subunits. It is shown that the Rbp10 subunit from Sz. pombe can substitute its homolog (ABC10 beta) in the baker's yeast S. cerevisiae.

[Molecular evolution and structure of eukaryotic nuclear RNA polymerase subunits in light of the exon-intron organization of their genes]. / Molekuliarnaia évoliutsiia i struktura sub''edinits iadernykh RNK-polimeraz éukariot v svete ékzon-intronnoi organizatsii ikh genov.

Analysis of literary data (for Saccharomyces cerevisiae, Caenorhabditis elegans, Arabidopsis thaliana, Homo sapiens, and some other Eucarya) and our data (for Schizosaccharomyces pombe) on the exon-intron organization of the genes encoding subunits of nuclear RNA polymerases showed that introns in the orthologous genes from different organisms are arranged nonrandomly, namely, their positions, if projected on the map of the comparison of the amino acid sequences of the orthologous subunits, not infrequently coincide in evolutionarily distant species. As a rule, intron positions correspond to the boundaries of the structurally conserved regions (domains) or to the sites of possible turns of the polypeptide chain. For example, introns flank the secondary structure elements in the Rpb8 subunit with the known three-dimensional structure or the structure-function modules in subunits Rpb10 and Rpc10. These facts are in agreement with the idea of the ancient origin of introns, and with the notion of evolution of ancient protein sequences through the assembly of their genes from short protoexons selected by the nature as far back as the RNA world times. Comparative analysis of the primary structures of the subunits of eukaryotic RNA polymerases allowed us to reveal a nuclear localization signal in subunit Rpb10 and some hypothetical archaeal homologues of subunit Rpc10.

[Cloning of cDNA for RNA polymerase subunit from the fission yeast Schizosaccharomyces pombe by heterospecific complementation in Saccharomyces cerevisiae]. / Klonirovanie kDNK sub''edinitsy RNK-polimeraz deliashchikhsia drozhzhei Schizosaccharomyces pombe putem mezhvidovoi komplementatsii v Saccharomyces cerevisiae.

The rpb10 cDNA of the fission yeast Schizosaccharomyces pombe, encoding one of the five small subunits common to all three nuclear DNA-dependent RNA polymerases, was isolated from an expression cDNA library by two independent approaches: PCR-based screening and direct suppression by means of heterospecific complementation of a temperature-sensitive mutant defective in the corresponding gene of Saccharomyces cerevisiae. The cloned Sz. pombe cDNA encodes a protein Rpb10 of 71 amino acids with an M of 8,275 Da, sharing 51 amino acids (71% identity) with the subunit ABC10 beta of RNA polymerases I-III from S. cerevisiae. All eukaryotic members of this protein family have the same general organization featuring two highly conserved motifs (RCFT/SCGK and RYCCRRM) around an atypical zinc finger and an additional invariant HVDLIEK motif toward the C-terminal end. The last motif is only characteristics for homologs from eukaryotes. In keeping with this remarkable structural conservation, the Sz. pombe cDNA also fully complemented a S. cerevisiae deletion mutant lacking subunit ABC10 beta (null allele rpb10-delta 1::HIS3).

[Synthesis of the mature human interleukin-1(alpha) gene by amplification of an mRNA-cDNA duplex in vitro]. / Sintez gena zrelogo interleikina 1alpha cheloveka putem amplifikatsii in vitro dupleksa mRNK-kDNK.

Mixture of polyadenylated mRNAs from human monocytes has been subjected to the reverse transcription specifically initiated from the mRNA encoding interleukin 1 alpha by a synthetic polynucleotide complementary to the mRNA's coding 3'-end to yield the corresponding mRNA-cDNA duplex. Under conditions of the polymerase chain reaction, with the above polynucleotide as a downstream primer and an upstream primer corresponding to the beginning of the mature interleukin 1 alpha (AA 113-271) gene, the mRNA-cDNA duplex yielded the desired gene, whose structure was proved by the restriction and sequence analyses. The gene, containing translation initiation and termination triplets, can be used for producing interleukin 1 alpha in various expression systems and as a probe in studies of the lymphokine's biosynthesis. This method of the gene synthesis does not need construction and analysis of cDNA libraries nor synthesis of double-stranded DNA, and can, in principle, make use of the total (non-fractionated) cellular RNA.

[Chemico-enzymatic synthesis of the structural gene of yeast valine tRNA]. / Khimiko-fermentativnyi sintez strukturnogo gena valinovoi tRNK drozhzhei.

Structural gene coding for the yeast tRNA Val1 has been synthesized and cloned in the pBR322 DNA.

[Structural-functional characteristics of the Schizosaccharomyces pombe rpb8+ gene, coding the subunit of RNA polymerase I-III, specific only for eukaryotes]. / Strukturno-funktsional'naia kharakteristika gena rpb8+ Schizosaccharomyces pombe, kodiruiushchego sub''edinitsu RNK-polimeraz I-III, specifichnuiu tol'ko dlia éukariot.

A full-length cDNA of the rpb8+ gene encoding a common subunit Rpb8 of nuclear RNA polymerases I-III only specific for Eucarya was isolated from an expression library of the fission yeast Schizosaccharomyces pombe. The primary structure of the corresponding fragment of the Sz. pombe genome was also established. The rpb8+ gene contains two short introns, 59 and 48 bp long. Only short segments of homology were found upon comparing the Rpb8 subunit homologs from various eukaryotic species, and substantial differences exist between the corresponding proteins of unicellular and multicellular organisms. Subunit Rpb8 of Sz. pombe proved to be the smallest one among the known related proteins: it lacks the 21-aa fragment corresponding to amino acids residues 68-88 of the central part of the homologous subunit ABC14.5 of Saccharomyces cerevisiae. Accordingly, subunit Rpb8 of the fission yeast was not capable of substituting in vivo subunit ABC14.5 in nuclear RNA polymerases of the baker's yeast.

[Primer-dependent amplification of 2 sites of human beta-globin gene]. / Praimerzavisimaia amplifikatsiia dvukh uchastkov beta-globinovogo gena cheloveka.

The polymerase chain reaction (PCR) method has been used for amplification of two segments of the human beta-globin gene comprising most of pathogenic mutations in the gene.

[Artificial DNA splicing using directed ligation]. / Iskusstvennyi splaising DNK s pomoshch'iu napravlennogo ligirovaniia.

An approach to the directed genetic recombination in vitro has been devised, which allows for joining, in a predetermined chemical-enzymatic way, a series of DNA segments to give a precisely spliced polynucleotide sequence (DNA Splicing by Directed Ligation, SDL). The approach makes use of amplification, by several polymerase chain reactions (PCR), of the chosen DNA segments. The corresponding primers contain recognition sites of the class IIS restriction endonucleases, yielding protruding ends of unique primary structures. The protruding ends of the segments to be joined together are structurally predetermined to make them mutually complementary. Ligation of the mixture of the segments so synthesized gives the desired sequence in an unambiguous way. The suggested approach has been exemplified by the synthesis of a totally processed (intronless) gene encoding human mature interleukin-1 alpha.