Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study describes the establishment of T-cell lines from the peripheral blood of two Bloom syndrome (BS) patients and one healthy female by co-cultivation with a lethally irradiated human T-cell line (MT-2) carrying adult T-cell leukemia (ATL) virus (ATLV). The cell lines from normal and BS subjects exhibited cell surface markers compatible with T-cell origin, and BS T-cell lines retained the original cytogenetic characteristics of the syndrome. Even though phytohemagglutinin-stimulated BS lymphocytes from the two BS patients studied all showed high levels of sister chromatid exchange (SCE), one of the BS T-lines retained the high SCE level in 100% of the cells and the other BS T-line contained two populations, one with high SCE (70%) and the other with normal SCE (30%), at a relatively constant frequency over 6 months. Transformation of normal and BS cells by cocultivation with MT-2, which carries ATLV, did not cause karyotypic changes over 6 months. ATLV infection, chromosome instability, karyotypic abnormality and SCE in BS T-lymphocytes are also discussed.
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PMID:Transformation of Bloom syndrome T-lymphocytes by cocultivation with a lethally irradiated human T-cell line carrying type C virus particles. 630 51

Three types of tumors termed plasmacytomas (ABPC's), lymphosarcomas (ABLS's), and plasmacytoid lymphosarcomas (ABPL's) arise in BALB/c mice treated with pristane and Abelson murine leukemia virus (A-MuLV). While most ABPC's and BLS's contain integrated A-MuLV proviral genome and synthesize the v-abl RNA, most ABPL's do not. The ABPL tumors were examined for the expression of other oncogenes that may be associated with their transformed state, in the absence of transforming virus. These tumors expressed abundant c-myb RNA of unusually large size and showed DNA rearrangements of the c-myb locus.
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PMID:DNA rearrangement and altered RNA expression of the c-myb oncogene in mouse plasmacytoid lymphosarcomas. 668 62

Some specific chromosomal abnormalities are associated with certain cancers. The earliest description of such a specific association is the one of the Philadelphia chromosome and myelogenous leukemia (1960). Other congenital karyotype abnormalities are associated with specific cancers. Examples of these are Down's syndrome with leukemia and Klinefelter's syndrome with male breast cancer. Genetic diseases of increased chromosome breakage, or of defective chromosome repair, are associated with greatly increased cancer incidence. Three such diseases have been recognized: 1) Fanconi's anemia, associated with leukemias and lymphomas, 2) Bloom's syndrome, associated with acute leukemias and lymphosarcoma, and 3) ataxia telangiectasia, associated with Hodgkin's disease, leukemia, and lymphosarcomas. Ten percent of individuals with ataxia telangiectasia will develop one of these neoplasms. Individuals with certain of these syndromes display an unusually high radiosensitivity. Radiation therapy for cancers has been fatal in patients who received as low as 3000 rad. This remarkable radiosensitivity has been quantitated in cell cultures from such cases. Evidence suggests that the apparent sensitivity may reflect subnormal ability to repair radiation damage. The rapid proliferation of information in this field stems from the interdigitation of many disciplines and specialties, including cytogenetics, cell biology, molecular biology, epidemiology, radiobiology, and several others. This paper is intended for clinicians; it presents a structured analytic scheme for correlating and classifying this multidisciplinary information as it becomes available.
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PMID:Chromosomes, cancer and radiosensitivity. 686 20

Two children presenting with sporadic unilateral retinoblastoma and exhibiting a high degree of chromosome breakage were noted to have unusual facies, microcephaly and abnormal skin pigmentation. In the first child the pattern of both spontaneous and mitomycin-C-induced chromosome breakage was characteristic of Fanconi's anaemia although the degree of breakage was extreme. She also exhibited a striking increase in X-ray-induced chromosomal damage in G0 lymphocytes as measured by dicentric formation and increase in chromatid-type aberrations. She had a number of typical clinical features, including cafe-au-lait patches and abnormalities involving the kidney; however, she demonstrated neither the hypoplasia of radius and thumb nor the typical aplastic phase of this disorder. At age 22 months the child became anaemic with trilineage myelodysplasia, which was rapidly followed by the development of acute myeloblastic leukaemia. The early onset (at age 4 months) of retinoblastoma may have been associated with the underlying genomic instability. The second child exhibited a pattern of chromosome breakage characteristic of Bloom's syndrome, in addition to a moderate increase in damage induced by mytomycin-C. She had the typical stunted growth and malar hypoplasia of Bloom's syndrome although she did not demonstrate the frequently described erythematous 'butterfly rash' Although patients with Fanconi's anaemia and Bloom's syndrome are recognised to be at an increased risk of cancer, retinoblastoma has not previously been described in patients with either condition. We suggest that underlying recessive chromosome breakage syndromes may be underdiagnosed in paediatric cancer patients, with important implications for prognosis and genetic counselling.
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PMID:Retinoblastoma in association with the chromosome breakage syndromes Fanconi's anaemia and Bloom's syndrome: clinical and cytogenetic findings. 755 65

The present study was conducted on 13 patients with Fanconi anemia. 25 parents and 12 siblings. The chromosomal instability characteristic of this congenital breakage syndrome was associated with the presence of transferable clastogenic material in the plasma, as also reported previously for ataxia telangiectasia and Bloom's syndrome. While all plasma ultrafiltrates from homozygotes had chromosome damaging properties, the clastogenic material had to be concentrated in most heterozygotes to reach detectable levels. The clastogenic effect was exerted via the intermediacy of superoxide radicals, since it was regularly inhibited by superoxide dismutase (SOD). This adds further evidence for a prooxidant state in this hereditary disease. The autosustained clastogenic activity possibly plays a role in the progressive impairment of blood cell-producing bone marrow and may predispose patients to develop cancer and leukemia. Prophylactic use of antioxidants may be recommended, using clastogenic plasma activity as a guide.
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PMID:Transferable clastogenic activity in plasma from patients with Fanconi anemia. 760 48

Breast cancer is a disease moderately responsive to chemotherapy. While its curability is inversely related to the tumor burden, a relevant number of patients still progress to metastatic disease even after adjuvant chemotherapy. Also, high-dose chemotherapy appears promising, but can not yet be considered ultimately curative of breast cancer. Different variables, biological, kinetic and treatment-related, account for the clinical behaviour of this disease. In order to improve its curability, they will all need to be taken into account in planning future treatment strategies. One of the most effective ways to understand and predict the clinical behaviour of breast cancer is the development of appropriate mathematical models explaining its growth-patterns. Aim of this paper is to review the two fundamental models, the exponential and the Gompertzian. The exponential model is at the basis of the Skipper-Schabel and the Goldie-Coldman hypotheses, while the Norton-Simon hypothesis has been formulated from the gompertzian model. The latter appears to better fit the vast amount of clinical data which are presently available: from Bloom's analysis of untreated breast cancer patients, to the results of large clinical trials, to the data emerged from the recent meta-analysis. Characteristic of a gompertzian growth pattern is that exponential growth is matched by exponential retardation of growth. In 1943 Delbruck and Luria demonstrated that random mutations could account for the development of virus resistance in bacteria and were able to estimate the rate of mutation as a function of the growth rate of bacteria. Shortly after Law demonstrated that resistance to methotrexate in murine leukemia occurred similarly. The concept of combination chemotherapy actually derived from the idea that cancer cells could be resistant to chemotherapy even before exposure to it. Goldie and Coldman applied the Delbruck/Luria model to hypothesize the use of non cross-resistant alternating combination chemotherapy as a better way to eliminate the risk of resistance. They also suggested that many different drugs were to be used as soon as possible, when the tumor size is still small. Most of their predictions were based on the Skipper/Schabel model of the exponential growth of cancer and on its deriving log-kill model. A large amount of clinical data are now suggesting that the behaviour of breast cancer is best described by gompertzian growth: in particular, gompertzian growth is a tenable model of breast cancer growth for both the unperturbed and the perturbed (by treatment) states.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Kinetics of breast neoplasms]. 815 80

Two new human DNA helicase genes, RecQ4 and RecQ5, that belong to the RecQ helicase family were cloned and characterized. The addition of these genes increases the total to five helicase genes in the human RecQ family, which includes helicases involved in Bloom and Werner syndromes, the genetic diseases manifesting the distinctive but overlapping clinical phenotypes of immunodeficiency, premature aging, and an enhanced risk of cancer. The RecQ4 helicase is as large as the Bloom (BLM) and Werner (WRN) helicases, and its gene expression profile is organ-specific, resembling that of BLM helicase. In contrast, the RecQ5 helicase has a low molecular weight, similar to the human progenitor RecQ1 helicase, and is expressed in all the organs examined. All five human helicase genes are expressed in cultured K562 leukemia and fibroblast cells. Synchronized K562 cell cultures showed that the genes RecQ4 and BLM, and RecQ1 and WRN, seem to be upregulated at the G1/S and G2/M phases, respectively, of the cell cycle. The biological significance of multiple species of human RecQ helicases, which are apparently nonessential for life but may be related to distinct diseases, is discussed in light of the fact that unicellular organisms, like Escherichia coli and yeast, contain only one species of helicase of this particular family.
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PMID:Cloning of two new human helicase genes of the RecQ family: biological significance of multiple species in higher eukaryotes. 987 47

Promyelocytic leukaemia (PML) nuclear bodies are present in most mammalian cell nuclei. PML bodies are disrupted by PML retinoic acid receptor alpha (RAR alpha) oncoproteins in acute promyelocytic leukaemia. These bodies contain numerous proteins, including Sp100, SUMO-1, HAUSP(USP7), CBP and BLM, and they have been implicated in aspects of transcriptional regulation or as nuclear storage depots. Here, we show that three classes of PML nuclear bodies can be distinguished, on the basis of their dynamic properties in living cells. One class of PML bodies is particularly noteworthy in that it moves by a metabolic-energy-dependent mechanism. This represents the first example of metabolic-energy-dependent transport of a nuclear body within the mammalian cell nucleus.
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PMID:Metabolic-energy-dependent movement of PML bodies within the mammalian cell nucleus. 1175 75

Persons with the autosomal recessive disorder Bloom syndrome are predisposed to cancers of many types due to loss-of-function mutations in the BLM gene, which encodes a recQ-like helicase. Here we show that mice heterozygous for a targeted null mutation of Blm, the murine homolog of BLM, develop lymphoma earlier than wild-type littermates in response to challenge with murine leukemia virus and develop twice the number of intestinal tumors when crossed with mice carrying a mutation in the Apc tumor suppressor. These observations indicate that Blm is a modifier of tumor formation in the mouse and that Blm haploinsufficiency is associated with tumor predisposition, a finding with important implications for cancer risk in humans.
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PMID:Enhanced tumor formation in mice heterozygous for Blm mutation. 1224 42

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


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