Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Since initial studies identifying the important role of vitamin A and its derivatives (retinoids) in maintaining the integrity of epithelial tissues, these compounds have served as paradigms for experimental studies exploring the pharmacologic modification of carcinogenesis. Retinoids have clearly been shown to inhibit chemically induced mammary and urothelial carcinogenesis in experimental animals. Prohibitive toxicity of the parent compound, vitamin A, led to a systematic search for synthetic derivatives with an improved therapeutic index. More than 1500 such compounds have been synthesized, many retaining chemopreventive potential, but with less toxicity. Although several anecdotal reports confirming therapeutic benefits of cis-retinoic acid in patients with acute promyelocytic leukemia and myelodysplastic syndromes appeared in the late 1970s and early 1980s, the remarkable studies of Huang and his colleagues in China in 1988 reporting complete remissions in patients with this uncommon variety of acute myelogenous leukemia with the transisomer of retinoic acid (all-trans-retinoic acid) led to a resurgence of interest in the retinoids as differentiating agents for the prevention and therapy of cancer. Furthermore, molecular studies showing DNA rearrangements of the alpha nuclear receptor for retinoic acid located on chromosome 17 in patients with acute promyelocytic leukemia, a disease invariably associated with a translocation between chromosomes 15 and 17, provided a direct connection between an altered nuclear receptor and the development of a human malignancy. The retinoids also may have important beneficial effects in prevention of recurrent malignancies once the primary tumor has been treated, such as in squamous cell carcinoma of the head and neck. Because retinoids appear to be less effective in inducing differentiation in nonpromyelocytic leukemia cells, investigators have conducted a number of studies to exploit potential synergism between retinoids and other differentiating agents or biologic effectors. Differentiation therapy and chemoprevention are attractive alternative approaches to intensive cytotoxic chemotherapy. It is now clear that retinoids represent one class of compounds with which it may be possible to reverse the progression of malignant disease and prevent carcinogenesis.
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PMID:Retinoids in cancer treatment. 144 94

The frequency of chromosome aberrations in the peripheral blood of patients successfully treated for Hodgkin's disease (HD) and non-Hodgkin's lymphoma is compared with that seen in age-matched haematologically normal subjects. Findings are considered in relation to risk factors associated with the development of secondary myelodysplastic syndrome (MDS) or acute myeloid leukaemia (AML). Overall aberration frequencies were not significantly increased in patients compared with normal subjects. However, there were differences in aberration type. The frequency of exchanges was significantly higher among patients (P less than 0.01) and the frequency of gaps lower (P less than 0.0005). The mean frequency of exchanges was also greater in patients receiving multiple compared to single courses of therapy (P less than 0.0005) and in patients receiving radiotherapy or combined modality therapy compared to chemotherapy alone (P less than 0.005 and P less than 0.0005). Four patients had aberration frequencies greater than 2 SD above the patient mean. One of these was also found to have a mutation of the ras oncogene. None of the patients has yet developed secondary MDS/AML.
Carcinogenesis 1992 Jul
PMID:Chromosome aberrations following cytotoxic therapy in patients in complete remission from lymphoma. 163 73

The clonal malignancies of acute myeloid leukemia and the myelodysplastic syndromes are associated with numerous chromosomal and oncogenic abnormalities. Activation of oncogenes has been demonstrated, although there is little evidence that this alone causes malignant transformation of diploid cells as a consequence. Patterns of abnormalities can be seen as the patient progresses from myelodysplastic syndrome to acute myeloid leukemia, but no unique or invariant findings have been described. Chromosomal changes, with the exception of some translocations, are neither disease nor lineage specific. At this time the data provide good support for the multistep view of carcinogenesis, and there is indirect or circumstantial evidence for the presence of tumor suppressor genes on 5q and 7q. The continued study of these clonal hematological disorders will provide considerable insight into mechanisms of tumorigenesis and possibly may lead to new modes of therapy, for example, through altering the microenvironment, interfering with deranged signal transmission, or introducing antioncogenes.
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PMID:Oncogene involvement in myelodysplasia and acute myeloid leukemia. 224 55

The activity of the DNA excision repair enzyme uracil-DNA glycosylase was measured in peripheral blood mononuclear cells and in bone marrow aspiration samples obtained from patients with pernicious anemia (PA) or other types of megaloblastic anemia (one case of tapeworm anemia and three cases of myelodysplastic syndromes). In addition, the expression of uracil-DNA glycosylase was investigated in biopsies from the antrum and body of the stomach obtained from nine PA patients, from five patients having atrophic gastritis (AG) not associated with PA, and from six control patients having transient upper abdominal complaints without AG. Our results revealed that there was a considerable interindividual variation in gastric uracil-DNA glycosylase activity. No clear correlation between the enzyme level and the level of gastric atrophy was noted, although AG is generally regarded as a risk factor of gastric cancer. Furthermore, uracil-DNA glycosylase activities in peripheral blood mononuclear cells and in bone marrow cells in PA and in myelodysplastic syndromes were similar to the activities observed previously in non-hematological patients and healthy persons. Transient uracil incorporation into DNA may have a role in the cellular abnormalities associated with megaloblastic hematopoiesis. The present findings demonstrated that the enzymatic activity required for rapid removal of uracil from DNA is also expressed in the megaloblastic state.
Carcinogenesis 1987 Feb
PMID:Hematopoietic and gastric uracil-DNA glycosylase activity in megaloblastic anemia and in atrophic gastritis with special reference to pernicious anemia. 380 19

The myelodysplastic syndromes comprise a heterogeneous group of hematopoietic disorders characterized by peripheral cytopenia, and ineffective and dysplastic hematopoiesis. Patients are predominantly aged, and often develop acute non-lymphocytic leukemia. Bone marrow failure, notably infection and bleeding, is the most common cause of death. Our understanding of the biology of the myelodysplastic syndromes is limited and thus reduces the efficacy and specificity of therapeutic intervention. Available evidence, however, suggests that the myelodysplastic syndromes arise from hematopoietic stem cells. The emergence and progression of the myelodysplastic clone have been reviewed in the light of the multistep theory of human carcinogenesis.
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PMID:[Myelodysplastic syndromes--clinical and biological features]. 831 82

The EVI-1 gene was originally detected as an ectopic viral insertion site and encodes a nuclear zinc finger DNA-binding protein. Previous studies showed restricted EVI-1 RNA or protein expression during ontogeny; in a kidney and an endometrial carcinoma cell line; and in normal murine oocytes and kidney cells. EVI-1 expression was also detected in a subset of acute myeloid leukaemias (AMLs) and myelodysplasia. Because EVI-1 is expressed in the urogenital tract during development, we examined ovarian cancers and normal ovaries for EVI-1 RNA expression using reverse transcription polymerase chain reaction (RT-PCR) and RNAase protection. Chromosome abnormalities were examined using karyotypes and whole chromosome 3 and 3q26 fluorescence in situ hybridisation (FISH). RNA from six primary ovarian tumours, five normal ovaries and 47 tumour cell lines (25 ovarian, seven melanoma, three prostate, seven breast and one each of bladder, endometrial, lung, epidermoid and histiocytic lymphoma) was studied. Five of six primary ovarian tumours, three of five normal ovaries and 22 of 25 ovarian cell lines expressed EVI-1 RNA. A variety of other non-haematological cancers also expressed EVI-1 RNA. Immunostaining of ovarian cancer cell lines revealed nuclear EVI-1 protein. In contrast, normal ovary stained primarily within oocytes and faintly in stroma. Primary ovarian tumours showed nuclear and intense, diffuse cytoplasmic staining. Quantitation of EVI-1 RNA, performed using RNAase protection, showed ovarian carcinoma cells expressed 0 to 40 times the EVI-1 RNA in normal ovary, and 0-6 times the levels in leukaemia cell lines. Southern analyses of ovarian carcinoma cell lines showed no amplification or rearrangements involving EVI-1. In some acute leukaemias, activation of EVI-1 transcription is associated with translocations involving 3q26, the site of the EVI-1 gene. Ovarian carcinoma karyotypes showed one line with quadruplication 3(q24q27), but no other clonal structural rearrangements involving 3q26. However, whole chromsome 3 and 3q26 FISH performed on lines with high EVI-1 expression showed translocations involving chromosome 3q26. EVI-1 is overexpressed in ovarian cancer compared with normal ovaries, suggesting a role for EVI-1 in solid tumour carcinogenesis or progression. Mechanisms underlying EVI-1 overexpression remain unclear, but may include rearrangements involving chromosome 3q26.
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PMID:Expression of the zinc finger gene EVI-1 in ovarian and other cancers. 893 29

Since the late 1970s, a comprehensive search for cancer chemopreventive agents has been established in our Institute. A series of new retinoids have been synthesized and screened on the basis of established methodologies of experimental chemoprevention in vitro as well as in vivo. Pharmacological studies demonstrated that N-4-(carboxyphenyl)retinamide (RII) induces cell differentiation of HL-60 cells and inhibits dimethylnitrosamine-induced carcinogenesis of the forestomach in mice, 7,12-dimethylbenz[a]anthracene (DMBA)-induced papilloma in mouse skin, and DMBA-induced carcinogenesis of the buccal pouch in Syrian golden hamsters. It significantly promoted lymphoblastic transformation and activated macrophages. In further studies, RII significantly inhibited ornithine decarboxylase activity. After 6 months of chronic toxicological studies in rats and dogs, RII was recommended for clinical trial. Phase II studies found that RII is effective in treating oral and vulvar leukoplakia. It is also effective in treating myelodysplastic syndrome and dysplasia of uterine cervix. The chalcone retinoidal compounds were discovered when the search for new retinoids with less toxicity and higher potency led to third-generation retinoids, which were synthesized and screened. Structure-activity relationship studies found that 3,5-di-tert-butyl-4-methoxy-4-carboxyl chalcone (R9158) is the most active inhibitor of a variety of cancer cells. It has no effect on the Colony Forming Unit-Granulocyte/Macrophage (CFU-GM) of bone marrow in mice. In in vivo studies, R9158 showed a remarkable inhibition of chondrosarcoma in rats. It had no cross-resistance to vincristine, but was cross-resistant to all-trans retinoic acid. Red ginseng, a processed Panax ginseng, is considered a typical tonic in traditional Chinese medicine. Our studies demonstrated that red ginseng extract inhibited DMBA-induced skin papilloma significantly. Experiments showed that glycyrrhetinic acid inhibited croton oil-induced ear edema in mice. It also inhibited epidermal ornithine decarboxylase as well as the rapid DNA damage induced by the carcinogen benzo[a]pyrene (B[a]P). Our pharmacological studies demonstrated that Chinese gallotannin inhibited the malignant transformation of B[a]P-induced V79 cells in vitro and B[a]P-induced pulmonary adenoma in A/J mice in vivo significantly.
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PMID:Research and development of cancer chemopreventive agents in China. 959 Nov 87

Recent studies have elucidated that not only genetic alterations but also epigenetic changes may play an important role in carcinogenesis. In particular, de novo methylation of CpG islands within the promoter region associated with the inactivation of tumor suppressor genes (TSGs) has been demonstrated in various malignancies. Since de novo acute myelogenous leukemia shows frequent inactivation of the p15INK4B gene through the promoter methylation only, we investigated the methylation status of the p15INK4B gene in myelodysplastic syndrome (MDS). In MDS, the p15INK4B gene is also frequently hypermethylated at the promoter region located at the 5'-CpG island of exon 1. Association of frequent and strong methylation with high-risk MDS suggested that promoter methylation of the p15INK4B gene plays an important role as a late event during MDS progression. Since several TSGs and growth regulatory genes, including the p15INK4B gene, may be inactivated through promoter hypermethylation in hematological malignancies, modulation of the methylation status may be considered as a novel treatment modality in MDS.
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PMID:High-risk myelodysplastic syndromes and hypermethylation of the p15Ink4B gene. 1003 97

By using R-banding karyotypic analysis technique, the bone marrow (BM) cells were performed in 223 hematopoietic malignacies and 105 diopathic throbocytopenic purpura (ITP), which served as control. The following results were obtained: (1) Nonrandom chromosome loss (NCL), such as, -11, -14, -21, etc, which were found in the affected members of leukemia families, were found in about 30% sporadic ANLL, MDS and about 50% ALL, espedislly in 100% (5/5) CLL, but not found in ITP (P < 0.001). These results indicated that the familial nonrandom chromosome loss were associated with leukomogenesis. (2) Because most of BM cells are hypodiploed and have the same kinds of NCL in each cases of CLL, which can develop into ALL, ANLL and also cancers, ALL BM hypo- and hyper-diploid and/or polyploid cells might be origin of hypodiploid cells. (3) 28% (6/21) of pediatric patients with AL, MDS, or FA (Fanconi Anemia) have one parent, who have up to 30% BM hypodiploid cells and similar kinds of NCL and also have the rearrangement of C-erbB and abnormal proliferation of BM. The NCL were found in the three consecutive generations of a family with 5 ALL among 10 members of third generation. It indicated that the familial NCL might be inherited and be coded by a unknown gene alteration, which might be related to leukomo and carcinogenesis, because there are genes or their candidates for leukemia in the chromosomes 11, 14 and 21. (4) Based on the works of my colleages and I, the model of leukomo and carcinogenesis was proposed and the relationship between chromosome monosomy, deletion, translocations and leukomogenesis were showed elswhere. The significance of monosomy 11, 14 and 21 etc. were discussed briefly.
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PMID:[Relationship between the familial nonrandom chromosome loss (NCL) and leukomogenesis]. 1037 57

In the current era of advanced supportive care and administration of recombinant cytokines and other effective therapies, patients with congenital (inherited) marrow failure syndromes usually survive the early years of life and beyond. With the extended lifespan, a new "natural history" for these syndromes is evident. Although these disorders were always classified as "benign" historically, it is now evident that most of these conditions confer an inordinately high predisposition to myelodysplastic syndromes and acute myelogenous leukemia (MDS/AML). Since carcinogenesis occurs as a sequence of events that is driven by genetic damage and by epigenetic changes, the hypothesis is advanced that the first "hit" or leukemia-initiating step is the constitutional genetic mutation, itself, that initially manifests as a single lineage or multiple lineage marrow failure. The leukemic promotion and progression steps leading to MDS/AML can then ensue readily in the initiated pool of progenitors or stem cells. Thus, the distinction between benign and malignant hematology in the context of the inherited marrow failure disorders has become blurred and new definitions for these syndromes should be developed.
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PMID:Congenital Marrow Failure Syndromes and Malignant Hematopoietic Transformation. 1038 16


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