[Show abstract][Hide abstract] ABSTRACT: Increased expression of the insulin-like growth factor (IGF) family members, IGF1, IGF2, their receptors and binding proteins,
or combinations thereof has been documented in various malignancies including gliomas. The results of multiple investigations
suggest that the IGFs can play a paracrine and/or autocrine role in promoting tumor growth in situ during tumor progression
but that these roles may vary depending on the tissue of origin. Enhanced IGF1 expression was not found in glioblastomas and
it was supposed that IGF1 participation in the development of glial tumors may be substituted by protein products of highly
expressed other genes, also participating in PI3K and MAPK pathways. Increased expression of IGF-binding protein genes in brain tumors makes the picture even more complicated.
As other binding proteins, IGFBPs regulate the activity of their ligands by prolonging their half-life. The discrepancies
arising from conflicting evidence on the results obtained by different laboratories in human gliomas are discussed. Our data
highlight the importance of viewing the IGF-related proteins as a complex multifactorial system and show that changes in the
expression levels of any one component of the system, in a given malignancy, should be interpreted with caution. As IGF targeting
for anticancer therapy is rapidly becoming clinical reality, an understanding of this complexity is very timely.
Cytology and Genetics 04/2012; 45(5):303-317. · 0.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Aim. To investigate protein level of all subunits of the eukaryotic elongation translation factor eEF1H (eEF1A, eEF1Bα, eEF1Bβand eEF1Bγ) in glial tumors of human brain in comparison with normal brain. Methods. The eEF1H components content has been investigated in human glioblastoma clinical samples by Western blot analysis. Results. To determine the eEF1Bα, eEF1Bβ and eEF1Bγ content, the polyclonal antibodies against all eEF1H subunits were obtained. The tendency of the eEF1Bγ protein level to increase in glioblastomas was observed. There were no significant differences in the eEF1A, eEF1Bα and eEF1Bβ protein contents. Conclusions. In the previous report we analysed the expression of all eEF1H subunits in human glial brain tumor on the mRNA level. This study showed that eEF1Bγ was overexpressed while no significant changes in other eEF1H subunits were observed. It suggests a possible function of eEFBg which is cancer-related and is not connected with the functioning of eEF1H complex in translation.
[Show abstract][Hide abstract] ABSTRACT: Analysis of the expression of genes encoding myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP) in human
glial tumors was carried out for determination of the expression specificity of these genes according to tumor types and their
malignancy. Low levels of MBP mRNA in astrocytoma specimens of malignancy grades II-IV and significantly higher levels in
perifocal zones adjacent to them have been determined by Northern hybridization. Diffuse astrocytomas and anaplastic astrocytomas
are characterized mostly by a low level of MBP gene expression and high level of GFAP gene expression, but distinct subtypes
of diffuse and anaplastic astrocytomas with a high level of GFAP gene expression can also be detected that may be the reflection
of different oncogenic pathways. Very low levels or even absence of MBP mRNA were revealed in oligodendroglioma and all oligoastrocytomas.
Thus, Northern hybridization data are correlated with serial analysis of gene expression (SAGE). Obtained results show that
MBP is a nonspecific marker for tumors of oligodendroglial origin, but determination of relative levels of MBP and GFAP mRNAs
may be useful for glial tumor recognition. In such a way, these two genes together with YKL-40 and TSC-22, which we found
previously, can be included into the gene panel for determination of so-called “gene signatures” of brain tumors. However,
strict requirements in relation to a clinical value of these “gene signatures” cannot be formulated without verifying them
on a large number of clinical samples of tumors and valid control.
Cytology and Genetics 02/2009; 43(1):22-27. · 0.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Eukaryotic elongation factor 1 (eEF1) mediates the binding of aminoacyl-tRNA to the ribosome in GTP-dependent manner. eEF1 consists of four subunits: eEF1A, eEF1Bα, eEF1Bβ and eEF1Bγ. eEF1A has two different isoforms: eEF1A1 is present throughout development and is ubiquitously expressed with the exception of adult muscle, while eEF1A2 is developmentally regulated and expressed only in muscle cells and neurons. Expression of eEF1A1, eEF1A2, eEF1Bα, eEF1Bβ and eEF1Bγ genes was analyzed by Northern blot hybridization of a panel of brain tumor and normal brain tissue RNAs. Totally 23 glioblastoma and 10 normal brain samples were investigated. In gliomas, no meaningful difference in the mRNA content for the eEF1A1, eEF1Bα and eEF1Bγ subunits as compared to normal brain tissues was found. However, we have observed approximately 2-fold decrease in the eEF1Bβ mRNA expression in human gliomas as compared to normal human brain by Northern blot analysis. Besides, we have shown reduced level of the eEF1A2 mRNA expression in glioblastoma as compared to normal human glia.
[Show abstract][Hide abstract] ABSTRACT: Comparison of gene expression profiles in human normal brain and glioblastoma using SAGE database revealed 129 genes with 5-fold difference of expression level in glioblastoma (P<0.05), 85 of them were down-regulated. The number of genes with 5-fold down-regulated expression is lower in the diffuse and anaplastic astrocytomas. Five-fold decrease in the expression in the diffuse astrocytoma and nearly the same expression levels in the anaplastic astrocytoma and glioblastoma were revealed for 9 genes only. For overwhelming majority of inactivated genes in the low-grade astrocytoma the expression decreased progressively in the subsequent stages of malignant progression of astrocytoma, expression levels of some genes were very low or undetectable in glioblastoma, the most aggressive brain tumor. The decreased expression of selected genes in glioblastoma was confirmed by Northern analysis and RT-PCR. Some genes, described in this work, may encode the tumor suppressors and their decreased expression may play an important role in initiation and progression of human glioma.
[Show abstract][Hide abstract] ABSTRACT: To enhance glioblastoma (GB) marker discovery we compared gene expression in GB with human normal brain (NB) by accessing SAGE Genie web site and compared obtained results with published data. Nine GB and five NB SAGE-libraries were analyzed using the Digital Gene Expression Displayer (DGED), the results of DGED were tested by Northern blot analysis and RT-PCR of arbitrary selected genes. Review of available data from the articles on gene expression profiling by microarray-based hybridization showed as few as 35 overlapped genes with increased expression in GB. Some of them were identified in four articles, but most genes in three or even in two investigations. There was found also some differences between SAGE results of GB analysis. Digital Gene Expression Displayer approach revealed 676 genes differentially expressed in GB vs. NB with cut-off ratio: twofold change and P < or = 0.05. Differential expression of selectedgenes obtained by DGED was confirmed by Northern analysis and RT-PCR. Altogether, only 105 of 955 genes presented in published investigations were among the genes obtained by DGED. Comparison of the results obtained by microarrays and SAGE is very complicated because authors present only the most prominent differentially expressed genes. However, even available data give quite poor overlapping of genes revealed by microarrays. Some differences between results obtained by SAGE in different investigations can be explained by high dependence on the statistical methods used. As for now, the best solution to search for molecular tumor markers is to compare all available results and to select only those genes, which significant expression in tumor combined with very low expression in normal tissues was reproduced in several articles. 105 differentially expressed genes, common to both methods, can be included in the list of candidates for the molecular typing of GBs. Some genes, encoded cell surface or extra-cellular proteins may be useful for targeting gliomas with antibody-based therapy.
Cytology and Genetics 02/2007; 41(1):30-48. · 0.29 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A comparison of gene expression profiles in different types of human brain tumours and normal brain by Serial Analysis of Gene Expression (SAGE) revealed exceptionally high content of CTTGGGTTTT tag in meningioma and ependimoma SAGE-libraries. A search of the most relevant gene for this tag on the website "SAGE Anatomic Viewer" showed that it belonged to the nucleotide sequence of insulin-like growth factor II (IGF-II) gene as well as to the open reading frame 43 on a chromosome 11 (C11orf43). This nucleotide sequence encodes putative insulin-like growth factor II associated protein (IGF-IIA). mRNA for this protein is produced as a result of the processing of IGF-II gene primary transcript. Northern analysis of glial tumours and meningiomas showed the exceptionally high level of mRNA of IGF-II-associated protein in meningiomas. Protein, encoded by this mRNA, can play the important role in meningioma formation and may be used as their specific molecular marker.
[Show abstract][Hide abstract] ABSTRACT: Public database of Serial Analysis of Gene Expression (SAGE) was used for identification of potential human astrocytic glioma molecular markers. The comparison of nine glioblastoma SAGE-libraries, eleven anaplastic astrocytoma SAGE-libraries, eight diffusive astrocytoma SAGE-libraries, and five human normal brain SAGE-libraries revealed 57 genes with more than 5-fold increase of expression in astrocytic gliomas (P≤0.05) comparing to the human normal brain. Besides the genes expression changes which occur at the early stage of astrocytomas formations and are revealed also during the subsequent stages of progression, some changes are characteristic only of highly malignant stages of tumor development while they are absent in the tumors of low stage of malignancy. The analysis of revealed genes expression can be used for glial tumor molecular classification, diagnosis, prognostic evaluation and determination of potential targets for anticancer therapy.
[Show abstract][Hide abstract] ABSTRACT: Comparison of gene expression levels in astrocytic gliomas and human normal brain by SAGE revealed SPARC gene among those the expression of which increases most significantly (more than 5-fold, p 0.05). High level of the SPARCgene expression was detected in differentiated astrocytomas as well as in malignant glial tumors. Northern hybridization confirmed the SAGE results and showed that the SPARC gene expression elevated in astrocytomas of grade II-IV as compared to human normal brain. Two SPARC transcripts of about 2 and 3 kb length were detected almost in all the tumour samples. A longer mRNA is synthesized preferentially in tumour cells. The SPARC gene expression changes may play a role in the gliomas invasion and their angiogenesis. SPARC gene seems to be a specific invasion factor in view of our results on substantial enhancement of its expression in the gliomas of different malignancy grades and the corresponding literature data. Since the SPARC expression level is much higher in the tumours of low grades (differentiated astrocytomas) than that in the tumours of high grade (glioblastomas) this gene can not be regarded as a specific marker of increasing tumor aggressiveness.
[Show abstract][Hide abstract] ABSTRACT: Screening of human fetal brain cDNA library by glioblastoma (GB) and normal human brain total cDNA probes revealed 80 differentially hybridized clones. Hybridization of the DNA from selected clones and the same cDNA probes confirmed this difference for 38 clones, of which eight clones contained Alu-repeat inserts with increased levels in GB. Thirty clones contained cDNAs corresponding to mitochondrial genes for ATP synthase subunit 6 (ATP6), cytochrome c oxidase subunit II (COXII), cytochrome c oxidase subunit III (COXIII), NADH dehydrogenase subunit 1 (ND1), NADH dehydrogenase subunit 4 (ND4), and mitochondrial 12S rRNA. The levels of all these mitochondrial transcripts were decreased in glioblastomas as compared to tumor-adjacent histologically normal brain. Earlier we found the same for cytochrome c oxidase subunit I (COXI) Serial Analysis of Gene Expression (SAGE) showed lower content of the tags for all mitochondrial genes in GB SAGE libraries and together with our experimental data could serve as evidence of general inactivation of the mitochondrial genome in glioblastoma--the most malignant and abundant form of human brain tumor.
Cancer Letters 02/2005; 218(1):99-107. · 5.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 80 cDNA clones differentially hybridized with total cDNA probes of glioblastoma and normal human brain were revealed by differential hybridization of human fetal brain cDNA library. Hybridization of the DNA of selected clones with the same cDNA probes verified the difference for 38 clones. The levels of six nucleotide sequences from 6 clones containing Alu-repeats were increased in glioblastoma. 20 clones contained cDNAs corresponding to mitochondrial genes for ATP synthase subunit 6 (ATP6), cytochrome C oxidase subunit II (COXII), cytochrome C oxidase subunit III (COXIII), NADH dehydrogenase subunit 1 (ND1), NADH dehydrogenase subunit 4 (ND4) and mitochondrial 12S rRNA. The expression of all these mitochondrial genes was decreased in glioblastomas as compared to tumor-adjacent normal brain.
[Show abstract][Hide abstract] ABSTRACT: Public databases of the Cancer Genome Anatomy Project were used to quantify the relative gene expression levels in glioblastoma multiforme (GBM) and normal brain by Serial Analysis of Gene Expression (SAGE). Analysis revealed HC gp-39 among the genes with the most pronounced changes of expression in tumor cells. Northern hybridization confirmed the results of computer analysis and showed that enhanced expression of the HC gp-39 gene was mainly in GBMs and occasionally in anaplastic astrocytomas. Neither SAGE nor Northern analysis revealed the presence of HC gp-39 mRNA in the glioblastoma cell line, thus the detection of increased quantities of this mRNA in GBMs may be associated with activated macrophages. Since the numbers of infiltrating macrophages and small vessel density are higher in glioblastomas than in anaplastic astrocytomas or astrocytomas, the HC gp-39 gene can be used as a molecular marker in the analysis of malignant progression of astrocytic gliomas.
Cancer Letters 09/2003; 198(2):203-10. · 5.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Our objective was to identify differentially expressed genes involved in the pathogenesis of glioblastoma multiforme (GBM).
Screening of arrayed human fetal brain and human postnatal brain cDNA libraries was performed by differential hybridization with glioblastoma multiforme and human normal brain cDNAs.
Repeated differential hybridization of more than 100 cDNA clones selected by primary screening and analysis of RNA from adult normal brain and glial tumors showed 16 nucleotide sequences differentially expressed between normal brain and brain tumors. Among others, decreased content in astrocytic tumors was determined for TSC-22 mRNA corresponding to cDNA in the ICRFp507J1041 clone from human fetal brain cDNA library. Northern blot hybridization of RNA from different human brain tumors showed very low amounts of TSC-22 mRNA in most investigated samples of GBM, anaplastic astrocytoma, and some other tumors. Complete lack of expression of TSC-22 occurred in one sample of anaplastic astrocytoma, as well as in meningioma, brain sarcoma, sarcomatous meningioma, and oligodendroglioma. The differential expression of TSC-22 gene was confirmed by semiquantitative RT-PCR in 15 samples of astrocytomas WHO grade II-IV and three samples of normal brain.
Significantly decreased levels of TSC-22 mRNA in human brain and salivary gland tumors and antiproliferative role of TSC-22 strongly suggest a tumor suppressor role for TSC-22. J.
Journal of Surgical Oncology 02/2003; 82(1):57-64. · 2.64 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The comparison of gene expression in normal and tumour cells is one of the alternative approaches to determine genes involved in cancerogenesis. The comparison of gene expression profiles for normal brain and glioblastoma multiforme by utilising SAGEmap and ODD public databases of Cancer Genome Anatomy Project (CGAP) revealed that the expressions of the HC gp-39 and SOX-2 genes had the greatest changes in the tumor cells. The expression of HC gp-39 gene is 82 times and SOX-2 – 109 times greater in glioblastoma multiforme. Northern-analysis confirmed the results of computation and showed enhanced expression of the HC gp-39 gene only in glioblastoma multiforme and elevated level of SOX-2 mRNA in astrocytic tumours of different malignancy grades. Very likely that overexpression of the HC gp-39 gene may be related to upregulation of this gene in the activated macrophages which are more abundant during the terminal stages of astrocytic gliomas or due to cartilage metaplasia in glioblastoma. Expression of the SOX-2 gene was observed prevalently only in gliomas. We assume that increased activity of the SOX-2 gene in astrocytic tumours has an essential biological significance in the gtioma formation and the HC gp-39 gene may be used as a molecular marker for the glioblastoma diagnostics.
[Show abstract][Hide abstract] ABSTRACT: The identification and characterization of genes either induced or repressed in human brain tumors are important in understanding the mechanism of tumor initiation and progression, stages of malignancy, in developing new approaches to the diagnosis and treatment of tumors. In this paper, differential hybridization of arrayed human fetal brain and postnatal brain and postnatal brain cDNA libraries revealed differences in the rate of hybridization signals with total cDNA probes of the human brain and glioblastoma multiforme for more than 150 cDNA clones. Sixteen nucleotide sequences with changed contents in tumors were identified by repeated differential hybridization of the cDNA clones selected by primary screening with the same total cDNA probes of the human brain and glioblastoma multiforme and by Northern-hybridization of RNA samples from the human and glial tumors. The results of an analysis of the increased expression of the gene encoding apolipoprotein E. DNA-binding protein B, mitochondrial (16S and 12S) and cytoplasmic 28S rRNAs, Alu-containing transcripts, inactivation of cullin 1 gene and potential tumor suppressor gene TSC-22 are described.
[Show abstract][Hide abstract] ABSTRACT: At present some biological mechanisms assumed to initiate and promote astrocytoma formation have been partly revealed. Several putative genes in regions strongly suggested to harbour tumour suppressors should be identified. For example, these are the regions on the chromosomal arms 1p, 10p, 13q, 19g and 22g. More comprehensive approach in the analysis of astrocytomas includes gene expression determination in order to focus not only on the structural alterations but on the regulatory differences as well. Such changes in gene expression are important determinants of normal cellular physiology and, if disturbed, directly contribute to abnormal cellular physiology, including cancer. The search of new genes, the activation or inactivation of which is associated with the progression of astrocytic tumours, is still a goal of intensive investigations. In this work, more than a hundred cDNA clones differed in hybridization signals between human normal brain and glioblastoma multiform have been found by screening of high density grids of arrayed human fetal brain and human postnatal brain cDNA libraries. The repeated differential hybridization of the clones selected by primary screening, as well as the analysis of RNA from human adult normal brain and glial tumour samples have revealed 16 nucleotide sequences, which content had changed in tumours. The decreased content in astrocytic tumours has been determined for TSC-22 mRNA corresponding to cDNA in ICRFp507J 1041 clone from the library of human fetal brain cDNAs. The Northern blot hybridization of RNA from different human brain tumours has shown very low amount of TSC-22 mRNA in a bulk of the investigated samples of glioblastoma multiform, anaptastic astrocytoma, WHO grade II astrocytoma and some other tumours. The expression of TSC-22 gene has not been detected at all in astrocytoma WHO grade 11 as well as in meningioma, brain sarcoma, sarcomatous meningioma and oligodendroglioma (one sample of each tumor kind). The Southern blot hybridization has revealed the deletions in genomic loci of TSC-22 gene in two of three anaplastic astrocytomas analyzed. A significantly decreased level of the production of TSC-22 mRNA in the human brain tumours and, as it was shown previously, in the salivary gland tumours, an antiproliferative role of TSC-22 protein, the localization of TSC-22 gene in 13q14 region close to the known tumour suppressor retinoblastoma (Rb) gene, and the deletions in this genomic locus strongly evidence TSC-22 to be a tumour suppressor.
[Show abstract][Hide abstract] ABSTRACT: Meningiomas of the third ventricle, especially those located in its anterior part, are a rare occurrence. Two patients with meningiomas of the third ventricle are described. In one of them the tumor was removed successfully. Pneumoencephalography and positive ventriculography are of decisive importance in the diagnosis of these tumors. Analysis of the data in the literature and the authors' personal observations shows that timely removal of these tumors with the use of rational approaches and microsurgical techniques may yield satisfactory results.
[Show abstract][Hide abstract] ABSTRACT: Increased expression of the insulin-like growth factor (IGF) family members, IGF1, IGF2, their receptors and binding proteins, or combinations thereof has been documented in various malignancies including gliomas. The results of multiple investigations suggest that the IGFs can play a paracrine and/or autocrine role in promoting tumor growth in situ during tumor progression but that these roles may vary depending on the tissue of origin. Enhanced IGF1 expression was not found in glioblastomas and it was supposed that IGF1 participation in the development of glial tumors may be substituted by protein products of highly expressed other genes, also participating in PI3K and MAPK pathways. Increased expression of IGF-binding protein genes in brain tumors makes the picture even more complicated. As other binding proteins, IGFBPs regulate the activity of their ligands by prolonging their half-life. The discrepancies arising from conflicting evidence on the results obtained by different laboratories in human gliomas are discussed. Our data highlight the importance of viewing the IGF-related proteins as a complex multifactorial system and show that changes in the expression levels of any one component of the system, in a given malignancy, should be interpreted with caution. As IGF targeting for anticancer therapy is rapidly becoming clinical reality, an understanding of this complexity is very timely.