Biomedical subjects

E Novikova

Publications and source records attributed to E Novikova.

4 recordsLinked to original sources

PubMed2001

The LMP1 gene isolated from Russian nasopharyngeal carcinoma has no 30-bp deletion.

The Epstein-Barr virus (EBV) is tightly linked to the induction of undifferentiated nasopharyngeal carcinoma (NPC), a tumour endemic in certain areas of southeast Asia. The LMP1 gene encoded by EBV is a classical oncogene due to its ability to transform rodent fibroblasts. LMP1 is absolutely essential for transformation of B cells by the virus and is one of the few EBV genes found to be expressed in NPC. It was originally shown that the LMP1 gene from NPC harbours a deletion of 30 bp in the 3' part of the gene. However, this deletion is also present in the virus spread in healthy people of the areas endemic for NPC and also in other EBV-positive tumours as well as in healthy carriers. We isolated and sequenced the LMP1 gene obtained from tissue of 7 Russian patients with NPC and 1 German patient with an NPC-like tumour of the parotid gland (PG) and compared them with the LMP1 gene isolated from peripheral blood lymphocytes (PBLs) of 6 Russian and 4 German healthy EBV-positive carriers. Neither the Russian NPC cases nor the German NPC-like tumour harboured an LMP1 gene with the 30-bp deletion, while 1 Russian and 2 German carriers contained the LMP1 gene with the 30-bp deletion. In addition, the LMP1 gene isolated from PBLs of the German patient was virtually identical to the gene isolated from the primary tumour. Functional analysis showed no correlation between the presence or absence of the 30-bp deletion and the level of induction of the transcription factors NFkappaB and jun/AP-1 caused by LMP1. These data indicate that the 30-bp deletion is not a factor predisposing for NPC. Comparison of the DNA sequences revealed that the LMP1 genes present in the NPCs most likely represent the "strain" persisting in the general population.

Adolescent↗

PubMed2001

Metallocarboxypeptidase Z is dynamically expressed in mouse development.

Metallocarboxypeptidase Z (CPZ), a new member of the regulatory metallocarboxypeptidases, contains a 120-residue cysteine-rich region that has 20-35% amino acid sequence identity to Drosophila and mammalian frizzled proteins. In order to gain insights into the function of CPZ, we have examined the distribution of the protein by immunohistochemistry throughout mouse development. The expression of CPZ peaks at E9-E12, decreases in late gestation and falls further in adult tissues. CPZ expression in amnion cells, cochlear epithelial cells and surrounding mesenchyme, ventricular lining cells in the brain and cartilagenous condensations and surrounding connective tissue in ribs remains at high levels throughout mouse gestation. The expression pattern of CPZ overlaps with the expression pattern of several Wnt genes, consistent with the putative role of CPZ in Wnt signaling.

Animals↗

PubMed1998

Human testicular glutathione S-transferases: insights into tissue-specific expression of the diverse subunit classes.

Cytosolic glutathione S-transferase (GST) subunits from human testis were resolved by HPLC and unambiguously identified by combined use of peptide sequence-specific antisera and electrospray ionization mass spectrometry (ESI MS). Allelic variants of hGSTP1, hGSTM1 and hGSTA2 were distinguished on the basis of observed differences in their molecular masses. Relative amounts of the multiple different subunit types in various human tissues were determined from HPLC profiles. From this type of analysis, tissues from hGSTM1 null allele individuals were readily discerned at the protein level; liver was the only tissue in which the hGSTM1 subunit was the major mu-class GST. hGSTM4 and hGSTM5 subunits were found at very low levels in all tissues examined. By far the tissue richest in the unique hGSTM3 subunit was testis, although brain also has significant levels.

Aged↗

PubMed1998

Rationale for reclassification of a distinctive subdivision of mammalian class Mu glutathione S-transferases that are primarily expressed in testis.

A rat testicular Mu-class glutathione S-transferase (GST) resolved by reversed-phase high performance liquid chromatography cross-reacted with peptide sequence-specific antisera raised against the human hGSTM3 subunit. Electrospray ionization mass spectrometry indicated that this rat GST subunit (designated rGSTM5 in this report) has a significantly greater molecular mass (26,541 Da) than the other rat GST subunits. The mouse homologue (mGSTM5 subunit) was also identified and characterized by high performance liquid chromatography and electrospray ionization mass spectrometry. Sequence analysis of rGSTM5 peptide fragments and the sequence deduced from a cDNA clone showed that the protein is highly homologous to the hGSTM3 and murine mGSTM5 subunits. All three GSTs of this subclass have N- and C-terminal extensions with C-terminal cysteine residues, but the two penultimate amino acids near the C terminus are divergent in the three species. The proteins of this class Mu subfamily have similar catalytic specificities and mechanisms, are all cysteine rich, are found mainly in testis, and share characteristics that distinguish them from other GSTs. Moreover, the rGSTM5 subunit isolated from rat testis was not found in heterodimeric combination with other common Mu-class GST subunits. As the rGSTM5, mGSTM5, and hGSTM3 subunits are structurally more closely related to each other than they are to other Mu GSTs, it is proposed that they be considered a functionally distinct and separate subfamily within class Mu. The identification of this unique mammalian GST subclass could advance strategies for interspecies comparisons of GSTs and provides a rodent model for studies on functions and regulatory mechanisms for human GSTs.

Amino Acid Sequence↗