Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q06643 (non-Hodgkin's lymphoma)
 11,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Unbalanced translocations as well as interstitial deletions of the short arm of chromosome 12 [del(12p)] are found as recurring chromosomal changes in a broad spectrum of hematopoietic malignancies. These changes result in the hemizygous deletion of genetic material from 12p. We mapped a yeast artificial chromosome containing the TEL gene, a cosmid contig containing part of TEL and a P1 contig containing the KIP1 gene to 12p13. These probes were used for fluorescence in situ hybridization to analyze samples from 47 patients with various hematologic malignancies who had unbalanced translocations (25 patients) leading to loss of 12p or deletions (22 patients) involving 12p13. The patients had acute lymphoblastic leukemia (8 cases), myelodysplastic syndrome (MDS; 11 cases), acute myeloid leukemia (AML; 10 cases), myeloproliferative disorders (4 cases), therapy-related MDS or AML (7 cases), non-Hodgkin's lymphoma (2 cases), and other hematopoietic malignancies (5 cases). All three probes were hemizygously detected in 26 cases and were completely retained in only 9 cases. In 12 cases probes for one of the two genes were deleted, allowing us to map the smallest region of overlap of these deletions to a small genomic region that is bordered on the telomeric side by the TEL gene and on the centromeric side by KIP1. The genomic distance between TEL and KIP1 is estimated to be about 1 to 2 Mbp.
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PMID:TEL and KIP1 define the smallest region of deletions on 12p13 in hematopoietic malignancies. 763 60

Twenty patients with hematologic malignancies with 12p abnormalities were investigated by fluorescence in situ hybridization (FISH) using probes mapped to specific regions in 12p. The initial analysis using the YAC 964c10 (D12S736) revealed that all four cases with cytogenetically identified del(12p) had lost one copy of this YAC and that submicroscopic deletions had occurred in 10 of the 16 neoplasms with other 12p abnormalities, ie, translocations, additions, and insertions. The deletions were partially mapped with cosmids localized to subregions of 12p. One copy of the gene for p27kip1 (KIP1), involved in cell cycle entrance, was found to be lost in all cases in which deletions could be detected by other probes and in one case with a translocation as the only detectable change. This implicates KIP1 as a possible tumor suppressor gene affected by del(12p). Four translocations with no apparent concomitant deletions were detected. All four breakpoints resulted in a split D12S736 signal. In two of these cases, we showed that TEL was disrupted as a result of a t(5;12)(q32-33;p12) and a t(12;22)(p12;q12), respectively. Two lymphoid neoplasm--one non-Hodgkin's lymphoma and one Burkitt's lymphoma--with 12p amplifications were detected. In both cases cyclin D2 (CCND2) was within the amplified region. Thus, cytogenetic abnormalities of 12p in hematologic malignancies result in at least three different molecular changes: deletions of KIP1, amplifications of CCND2, and structural rearrangements of TEL.
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PMID:Molecular characterization of 12p abnormalities in hematologic malignancies: deletion of KIP1, rearrangement of TEL, and amplification of CCND2. 854 59

The recurrent (12;21)(p13;q22) translocation fuses the two genes TEL and AML1 that have previously been cloned from translocation breakpoints in myeloid leukemias. Using mainly reverse transcriptase-polymerase chain reaction (RT-PCR), the TEL-AML1 chimeric transcript has been observed in 22-27% of pediatric patients with acute lymphoblastic leukemia (ALL), in particular in the early B-lineage ALL subtype, making it the most common genetic lesion in these patients. The vast majority of acute myeloid leukemias, other ALL subtypes and even adults with early B-lineage ALL were TEL-AML1-negative. We determined whether the TEL-AML1 fusion gene can also be observed in continuous human leukemia cell lines with an early B-lineage phenotype. Twenty-nine such cell lines established from children (n = 13) or adults (n = 13) with early B-lineage ALL and five cell lines derived from chronic myeloid leukemia in blast crisis or B cell non-Hodgkin's lymphoma were investigated for the occurrence of the TEL-AML1 rearrangement by RT-PCR. While all 13 adult early B-lineage ALL cell lines and the five cell lines from other leukemias or lymphomas were negative, 1/13 pediatric cell lines (cell line REH) was found to be positive for TEL-AML1; though neither reciprocal AML1-TEL, nor normal TEL, mRNA was detectable by RT-PCR in this cell line. These findings agreed with the results of conventional cytogenetic and FISH analysis of REH which was found to carry the der(21) partner only of t(12;21)(p13;q22), probably resulting from a complex translocation, t(4;12;21;16)(q32;p13;q22;q24.3). Hybridization with flanking cosmid clones (179A6 and 148B6), covering exons 1 and 8 respectively of TEL, confirmed a rearrangement accompanying the t(12;21), and showed cryptic deletion of the residual allele resulting from an apparently reciprocal t(5;12)(q31;p13). These findings in REH provide a further example of, and possible cytogenetic mechanism for, the paradigm of TEL-AML1 fusion accompanied by deletion of the residual TEL allele. The low rate of early B-lineage ALL cell lines carrying this translocation contrasts clearly with the relative high frequency of TEL-AML1-positive cases in primary material. It is possible that expression of the fusion product hampers the in vitro growth and establishment in culture of such leukemic cells. Nevertheless, the cell line REH represents a powerful tool for the further molecular characterization of this unique breakpoint and can serve as a positive control in routine PCR reactions.
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PMID:Occurrence of TEL-AML1 fusion resulting from (12;21) translocation in human early B-lineage leukemia cell lines. 906 87

The ETV6 (also known as TEL) gene on chromosome 12p13 is the target of a number of translocations associated with various hematologic malignancies. The contribution of ETV6 to leukemogenesis occurs through different mechanisms that involve either its helix-loop-helix dimerization domain or its E26 transformation-specific (ETS) DNA-binding domain. Using fluorescence in situ hybridization we characterized seven new ETV6 rearrangements in chronic myeloid leukemia, acute myeloid leukemia, acute lymphoblastic leukemia, and non-Hodgkin's lymphoma. These aberrations, not always discernible at the cytogenetic level, include a t(5;12)(q31;p13), t(6;12;17)(p21;p13;q25), t(7;12)(p15;p13), t(7;12)(p12;p13), t(7;12)(q36;p13), t(12;13)(p13;q12), and a not completely defined t(12;?)(p13;?). Loss or disruption of the second ETV6 allele by a del(12)(p12p13) or by an intragenic ETV6 deletion was detected in two cases. In six cases the 12p13 breakpoint occurred in the 5' end of ETV6, upstream to exons encoding the HLH domain, whereas the remaining case had a breakpoint between the exons coding for the HLH domain and the exons coding for the ETS domain of ETV6. These observations provide further evidence for the multiple contributions of ETV6 in the pathogenesis of a wide range of hematologic malignancies.
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PMID:Fluorescence in situ hybridization characterization of new translocations involving TEL (ETV6) in a wide spectrum of hematologic malignancies. 945 71

The PAX5 gene, encoding the B-cell-specific activator protein, is a critical determinant of commitment to the B-lymphocyte pathway. This gene, mapped at 9p13, is juxtaposed to the immunoglobulin heavy chain (IgH) gene as a result of the t(9;14)(p13;q32), a rare but recurring translocation found in a subset of B-cell non-Hodgkin's lymphoma cases. In all of these, this translocation results in deregulated expression of the gene product because of the proximity of IgH. We present here the molecular characterization of a previously reported acute lymphoblastic leukemia case carrying a t(9;12)(q11;p13) translocation. Using 5' rapid amplification of cDNA ends PCR, a novel chimeric transcript was identified that contained the NH(2)-terminal region of PAX5 and most of the ETV6/TEL gene on 12p13. According to the fusion transcript, the resulting chimeric protein would retain the PAX5 paired-box domain and both the helix-loop-helix and DNA binding domains of TEL. Thus, it is reasonable to hypothesize that this protein could act as an aberrant transcription factor. This is the first report of PAX5 rearrangement in a human malignancy resulting in a chimeric transcript.
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PMID:The paired box domain gene PAX5 is fused to ETV6/TEL in an acute lymphoblastic leukemia case. 1140 33

Fusion tyrosine kinases (FTKs) such as BCR/ABL, TEL/ABL, TEL/JAK2, TEL/PDGF beta R, TEL/TRKC(L), and NPM/ALK arise from reciprocal chromosomal translocations and cause acute and chronic leukemias and non-Hodgkin's lymphoma. FTK-transformed cells displayed drug resistance against the cytostatic drugs cisplatin and mitomycin C. These cells were not protected from drug-mediated DNA damage, implicating activation of the mechanisms preventing DNA damage-induced apoptosis. Various FTKs, except TEL/TRKC(L), can activate STAT5, which may be required to induce drug resistance. We show that STAT5 is essential for FTK-dependent upregulation of RAD51, which plays a central role in homology-dependent recombinational repair (HRR) of DNA double-strand breaks (DSBs). Elevated levels of Rad51 contributed to the induction of drug resistance and facilitation of the HRR in FTK-transformed cells. In addition, expression of antiapoptotic protein Bcl-xL was enhanced in cells transformed by the FTKs able to activate STAT5. Moreover, cells transformed by all examined FTKs displayed G(2)/M delay upon drug treatment. Individually, elevated levels of Rad51, Bcl-xL, or G(2)/M delay were responsible for induction of a modest drug resistance. Interestingly, combination of these three factors in nontransformed cells induced drug resistance of a magnitude similar to that observed in cells expressing FTKs activating STAT5. Thus, we postulate that RAD51-dependent facilitation of DSB repair, antiapoptotic activity of Bcl-xL, and delay in progression through the G(2)/M phase work in concert to induce drug resistance in FTK-positive leukemias and lymphomas.
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PMID:Fusion tyrosine kinases induce drug resistance by stimulation of homology-dependent recombination repair, prolongation of G(2)/M phase, and protection from apoptosis. 1202 32

Fusion tyrosine kinases (FTKs) such as BCR/ABL, TEL/ABL, TEL/JAK2, TEL/PDGF beta R and NPM/ALK arise from reciprocal chromosomal translocations and cause acute and chronic myelogenous leukemias and non-Hodgkin's lymphoma. Murine hematopoietic growth factor dependent BaF3 cells and cells transformed by FTK (BaF3-FTK) were used to investigate the role of FTKs in response to DNA damage. FTK-transformed cells displayed resistance to genotoxic treatment including gamma-radiation and cytostatic agents such as idarubicin and MNNG. More FTK-transformed cells survived genotoxic treatment and were able to proliferate in comparison to parental non-transformed cells. Similar or higher levels of DNA damage was detected in gamma-irradiated in BaF3-FTK cells in comparison to BaF3 parental cells. Idarubicin induced different amounts of DNA damage in various BaF3-FTK cells. All BaF3-FTK cells treated with MNNG displayed significantly more DNA damage in comparison to BaF3 cells. Despite the extent of genotoxic effect BaF3-FTK cells were often able to repair damaged DNA more efficiently that the non-transformed counterparts. Inhibition of BCR/ABL kinase activity by STI571 (Gleevec, inatinib mesylate) abrogated the resistance to genotoxic treatment and inhibited DNA repair mechanisms. We hypothesize that facilitation of the DNA repair in FTK-positive cells may contribute to their resistance to genotoxic treatment.
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PMID:Fusion oncogenic tyrosine kinases alter DNA damage and repair after genotoxic treatment: role in drug resistance? 1253 80

Germ-line mutations (present in all cells) in genes that are crucial for the cell cycle cause cancer only in specific cell lines (e.g. mismatch repair genes in the colon; BRCA1-2 in breast and ovary; other cancers in Bloom syndrome, neurofibromatosis and xeroderma pigmentosum). The mutation rate of genes other than mismatch repair or p53 is the same in colon cancer and in normal cells, indicating that a 'mutator phenotype', increasing the rate of mutations in many genes, is not an essential feature of sporadic cancers; conversely, fusion genes, TEL-AML1/AML1-ETO, typical of leukemia, are 100 times more frequent at birth than in overt leukemia in children, indicating that further selective events are needed to cause malignancy. The devastating impairment of immunity, as in AIDS patients, does not cause cancer other than Kaposi's sarcoma and non-Hodgkin's lymphoma, although immunological control is considered to be an essential mechanism in preventing the spread of cancer cells. These observations suggest that cell-specific additional events are needed to explain carcinogenesis. Carcinogenesis has been traditionally interpreted as the sequence of initiation (mutation) and promotion (clone expansion), with an interesting similarity with the neo-Darwinian theory of evolution, based on a first stage of genetic change (including recombination) and a second stage of selection. I propose that carcinogenesis consists in two general phases (not necessarily stages), i.e. genetic change followed by clone expansion (selective advantage). As in neo-Darwinian theory selection is chiefly represented by the elimination of the less fit, the selection of mutated cells would mainly consist in resistance to apoptosis or other types of 'bottlenecks' that hamper a cell's survival; an example of such a bottleneck is the autoimmunity that induces paroxysmal nocturnal hemoglobinuria in individuals with PIG-A mutations. Cancer rates show great variation in different countries around the world, a variation only marginally explained by genetic differences. More interestingly, migrants change their risk of cancer by adapting to that of the population into which they move: as these changes are not likely to be entirely due to mutagens in the environment, we have to invoke selective pressure over mutated cells to explain them. My theory is that mutated cells adapt to environmental 'niches' better than normal cells, in a 'gene-environment interaction' that involves the history of the genetic changes the cell has undergone and the kind of environment in which it happens to live.
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PMID:Cancer as an evolutionary process at the cell level: an epidemiological perspective. 1253 42

Multiplex reverse transcription-polymerase chain reaction (M-RT-PCR) has been proved to possess great clinical potential for simultaneous screening of 29 chromosomal translocations in acute leukemia. To evaluate the clinical value of M-RT-PCR in hematologic malignancies, bone marrow samples from 90 patients with various hematologic malignancies, including 25 acute myelogenous leukemia (AML), 22 acute lymphoblastic leukemia (ALL), 27 chronic myelogenous leukemia (CML), 4 myeloproliferative diseases (MPD), 3 chronic lymphoblastic leukemia (CLL), 3 non-Hodgkin's lymphoma (NHL), 3 myelodysplastic syndrome (MDS), 2 multiple myeloma (MM) and 1 malignant histiocytosis (MH) were subjected to both M-RT-PCR and chromosome karyotypic analysis. Some of cases were subjected to follow-up examination of M-RT-PCR during the period of clinical complete remission (CR) for detection of minimal residual leukemia. In our hand, 12 of 29 chromosomal translocation transcripts including TEL/PDGFR, DEK/CAN, MLL/AF6, AML1/ETO, MLL/AF9, BCR/ABL, MLL/MLL, PML/RARu, TLS/ERG, E2A/HLF, EVI1 and HOXI1 were detected in 57 cases (63.3 %) of the 90 samples, which were in consistency with the results of karyotypic analysis. Furthermore, M-RT-PCR had also shown good clinical relevance when used as an approach to detect minimal residual leukemia. We concluded that M-RT-PCR could be used as an efficient and fast diagnostic tool not only in the initial diagnosis of hematologic malignancies but also in subsequent monitor of minimal residual leukemia.
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PMID:Multiplex reverse transcription-polymerase chain reaction for simultaneous screening of 29 chromosomal translocation in hematologic malignancies. 1735 82