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 anti-leukemia activity of the saponin rich Gleditsia sinensis Lam. fruit extract (GSE) was investigated on cancer cell lines and bone marrow cells obtained from consented patients with chronic myelogenous leukemia (CML) and acute myelogenous leukemia (AML) during presentation. The growth inhibitory activity of the extract was determined by [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] (MTS) assay. Colony formation assay was performed to investigate the regeneration potential. Cellular morphology change was studied. Apoptosis was demonstrated by DNA electrophoresis, reverse transcription polymerase chain reaction (RT-PCR) and flow cytometry. The mean concentration to inhibit the cell growth by 50% (MTS50) was 18+/-1.6 micro g/ml for K562 CML cell line and 12+/-1.3 micro g/ml for HL-60 acute promyelocytic leukemia cell line. Patient samples showed a mean MTS50 of 13-28 micro g/ml. Non-malignant hematological disorder bone marrow samples showed a mean MTS50 from 45 to 53 micro g/ml. Loss of regeneration property after treatment with GSE of these two cancer cell lines were confirmed by colony formation assay. GSE was able to induce cell shrinkage in K-562. DNA laddering was observed by incubating the leukemia cells with GSE. RT-PCR demonstrated that the pro-apoptic gene bax was induced while the anti-apoptic gene bcl-2 and cell cycle active gene PCNA were reduced. Flow cytometric analysis showed that the apoptotic effect of GSE on leukemia cell line was time- and dose-dependent. Thus GSE might be potentially used as a chemotherapeutic drug to treat patients with acute and chronic myelogenous leukemia.
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PMID:Gleditsia sinensis fruit extract is a potential chemotherapeutic agent in chronic and acute myelogenous leukemia. 1288 47

Arsenicalism has been observed throughout the world and has become an urgent public health concern. The authors explored the mechanism of carcinogenesis of inorganic arsenic in patients with arsenicalism from coal-burning pollution. The 68 subjects were divided into 3 groups--carcinoma, precarcinoma, and common-on the basis of pathological diagnosis. The expressions of proliferating cell nuclear antigen (PCNA), mutant-type P53, and B-cell lymphoma/leukemia-2 (BCL-2) proteins were detected by immunohistochemical staining. PCNA, P53, and BCL-2 proteins were overexpressed. The proteins' overexpressions correlated with the pathological changes seen in each pathological study group (i.e., common < precarcinoma < carcinoma). Statistical correlation was observed between P53 and BCL-2, and between PCNA and BCL-2. The authors concluded that cell proliferation, antiapoptosis, and up-regulation of the mutant-type P53 gene played vital roles in the pathological development of arsenicalism.
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PMID:Molecular pathology of skin carcinogenesis due to arsenicalism from coal-burning. 1289 9

To investigate the effects of normal human bone m arrow fibroblastoid stromal cell line (HFCL) on the proliferation of acute myeloid leukemia cell line HL-60 and expression of vascular endothelial growth factor (VEGF), establishing coculture system of leukemia cell line HL-60 and HFCL, growth data was obtained by cell counting. Mitotic index (MI) was observed under Wright-Giemsa staining. Flow cytometry and Western blot were used as assays for cell cycle and expression of proliferating cell nuclear antigen (PCNA) separately. VE GF levels were evaluated by using commercial ELISA kits. The results showed that compared with HL-60 cells without HFCL cells, the proliferation of HL-60 cells in direct contact with HFCL cells and with HFCL cells separated by transwell was inhibited. The MI of HL-60 cells without HFCL cells was highest followed by HL-60 cells separated by transwell and HL-60 cells in direct contact with HFCL cells. The expression of PCNA in HL-60 cells with HFCL cells were lower than HL-60 cells without HFCL cells. Meanwhile, the percentage of HL-60 cells in G1 phase cocultured with HFCL cells was higher than that without HFCL cells while the percentage of Sphase cells was lower. The levels of VEGF in HL-60 cells with HFCL cells were lower than that in HL-60 cells alone. In conclusion, the normal bone marrow fibroblastoid stromal cells inhibited the proliferation of HL-60 cells as well as the expression of VEGF.
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PMID:[Effects of human fibroblastoid stromal cell line on proliferation of HL-60 cells and expression of VEGF]. 1457 40

The importance of epigenetic modifications in carcinogenesis has been a source of controversy for some time. There is little doubt that changes in genomic hypermethylation contribute to the silencing of tumor suppressor genes. Furthermore, recent studies have also identified the significance of genomic hypomethylation associated with chromosomal instability and tumorigenesis. One of the most perplexing questions regarding epigenetic modifications and leukemogenesis is the relationship with DNA methyltransferases (DNMT's). The primary function of the DNMT enzymes is to methylate genomic DNA, whereas the methyl-CpG binding domain proteins (MBD) interpret this methylation signal and regulate gene expression and chromatin behavior. In this study we analyse these gene families by quantitative real-time PCR to investigate whether expression levels and the B-cell chronic lymphocytic leukemia (B-CLL) phenotype are associated. Furthermore, given the epigenetic crosstalk between genome stability and the histone chromatin code we have analysed eukaryotic histone methyltransferase (Eu-HMTaseI). Surprisingly, we did not observe significant changes in DNMT1 expression in B-CLL cases when compared to normal lymphocytes, regardless of whether we normalise against GAPDH or PCNA as reference standards. Indeed, expression of the maintenance and de novo methylases were independently regulated. Of particular note was the significant down regulation of DNMT3b. Furthermore, we observed a positive correlation between HMTaseI expression levels and stage of leukemia suggesting that changes in the methylation patterns in B-CLL may represent deregulation of the epigenetic repertoire that also include the methylation dependent binding proteins, MBD2 and MeCP2. We envisage changes in the epigenetic program are multifactorial in nature and postulate that the prevalent genomic methylases just one component of a larger epigenetic repertoire.
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PMID:Expression analysis of the epigenetic methyltransferases and methyl-CpG binding protein families in the normal B-cell and B-cell chronic lymphocytic leukemia (CLL). 1546 27

Mammalian MTH1 proteins, homologs of Escherichia coli MutT, are enzymes decomposing 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate (8-oxo-dGTP) to 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-monophosphate and inorganic pyrophosphate. They play an antimutagenic role by preventing the incorporation of promutagenic 8-oxo-dGTP into DNA. MTH1 gene expression is higher in some physiological types of mammalian cells and in numerous cancer cells, but the mechanism of that upregulation still remains unclear. It has been hypothesized that MTH1 expression might be associated with a proliferation rate of the cells. Therefore, we tested this hypothesis by comparing the functional levels of MTH1 gene expression measured as the 8-oxo-dGTPase activity of its protein products in normal mouse livers and hepatectomized regenerating livers. Although the proliferation rate of the hepatocytes in the regenerating livers was much higher than that in control livers, as confirmed by immunohistochemical assay of proliferating cell nuclear antigen, the 8-oxo-dGTPase activity was not different. In a second approach, we used 57 lines of human cancer cells in which 8-oxo-dGTPase activity was measured and confronted with cell population doubling time. No significant correlations between 8-oxo-dGTPase activity and proliferation rate were observed within groups of six leukemia, eight melanoma, nine lung, seven colon, six central nervous system, six ovarian, eight renal, and seven breast cancer cell lines. Thus, we conclude that the MTH1 expression manifested as the 8-oxo-dGTPase activity of its protein products in mammalian cells is not associated with proliferation rate. Our results will help in further testing of the hypothesis that MTH1 overexpression may be a specific marker of carcinogenesis and/or oxidative stress.
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PMID:Cellular 8-oxo-7,8-dihydro-2'-deoxyguanosine 5'-triphosphate pyrophosphohydrolase activity of human and mouse MTH1 proteins does not depend on the proliferation rate. 1547 5

Expression of cyclin E is believed to be a critical factor promoting cell entry into the S-phase and cell proliferation. Indeed, normal proliferating cells and most tumor cell lines are characterized by the existence of a minimal cyclin E threshold level in the G1-phase, and only those cells expressing cyclin E over this threshold enter into the S-phase of the cell cycle. However, through studying clinical tumor tissue specimens, we recently observed that some cancer cells can enter into the S-phase with minimal levels of cyclin E expression. In an effort to establish an in vitro cell model system for studying the mechanisms underlying this phenomenon, we treated MOLT-4 lymphocyte leukemia cells with 50 mM caffeine and found that the levels of cyclin E expression were decreased markedly in these cells following 2 to 4-h exposure to caffeine. Quite unexpectedly, we observed that the percentage of the cells progressing through the S-phase increased despite the reduced levels of cyclin E, as analyzed for the cellular DNA contents, expression of nuclear-bound PCNA, immunolabelling with Ki-67 antibody and incorporation of BrdU. In fact, these cells entered into the S-phase with a level of cyclin E well below the threshold level for untreated cells, thus suggesting that lower levels of cyclin E expression are associated with cell proliferation under certain circumstances. We speculate that caffeine may enhance MOLT-4 cell entrance into the S-phase through activation of Cdc25, which in turn activates cyclin-dependent protein kinases (CDKs) including CDK2 and drives the cell cycle progression; while degradation of cyclin E by the ubiquitin/proteasome pathway may account for the decreased levels of cyclin E in these cells. Our findings from both the MOLT-4 cell line and patients' cancer tissues may help decipher the mystery of the deregulation of cell cycle progression and carcinogenesis in some malignant tumors.
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PMID:Down-regulation of cyclin E expression by caffeine promotes cancer cell entry into the S-phase of the cell cycle. 1551 6

Galpha(12), the alpha-subunit of the G12 family of heterotrimeric G proteins is involved in the regulation of cell proliferation and neoplastic transformation. GTPase-deficient, constitutively activated mutant of Galpha(12) (Galpha(12)Q229L or Galpha(12)QL) has been previously shown to induce oncogenic transformation of NIH3T3 cells promoting serum- and anchorage-independent growth. Reduced growth-factor dependent, autonomous cell growth forms a critical defining point at which a normal cell turns into an oncogenic one. To identify the underlying mechanism involved in such growth-factor/serum independent growth of Galpha(12)QL-transformed NIH3T3, we carried out a two-dimensional differential proteome analysis of Galpha(12)QL-transformed NIH3T3 cells and cells expressing vector control. This analysis revealed a total of 22 protein-spots whose expression was altered by more than 3-folds. Two of these spots were identified by MALDI-MS analysis as proliferating cell nuclear antigen (PCNA) and myeloid-leukemia-associated SET protein. The increased expressions of these proteins in Galpha(12)QL cells were validated by immunoblot analysis. Furthermore, transient transfection studies with NIH3T3 cells indicated that the expression of activated Galpha(12) readily increased the expression of SET protein by 24 h. As SET has been previously reported to be an inhibitor of phosphatase PP2A, the nuclear phosphatase activity was monitored in cells expressing activated Galpha(12). Our results indicate that the nuclear phosphatase activity is inhibited by greater than 50% in Galpha(12)QL cells compared to vector control cells. Thus, our results from differential proteome analysis presented here report for the first time a role for SET in Galpha(12)-mediated signaling pathways and a role for Galpha(12) in the regulation of the leukemia-associated SET-protein expression.
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PMID:Proteome analysis of NIH3T3 cells transformed by activated Galpha12: regulation of leukemia-associated protein SET. 1559 26

Acquired drug-resistance phenotype is a key factor in the relapse of patients suffering hematological malignancies. In order to investigate the genes involved in drug resistance, a human leukemia cell line that is resistant to doxorubicin, an anthracycline anticancer agent (AML-2/DX100), was selected and its gene expression profile was analyzed using a cDNA microarray. A number of genes were differentially expressed in the AML-2/DX100 cells, compared with the wild type (AML-2/WT). Pro-apoptotic genes such as TNFSF7 and p21 (Cip1/Waf1) were significantly down-regulated, whereas the IKBKB, PCNA, stathmin 1, MCM5, MMP-2 and MRP1 genes, which are involved in anti-apoptotic or cell cycle progression, were over-expressed. The AML-2/DX100 cells were also resistant to other anticancer drugs, including daunorubicin and camptothecin, and the expression levels of the differentially regulated genes such as STMN1, MMP-2 and CTSG, were constantly maintained. This suggests that the deregulated genes obtained from the DNA microarray analysis in a cell line model of drug resistance might contribute to the acquired drug resistance after chronic exposure.
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PMID:Monitoring the gene expression profiles of doxorubicin-resistant acute myelocytic leukemia cells by DNA microarray analysis. 1645 35

The anti-cancer agent paclitaxel (PTX) is an effective anti-restenosis agent on drug eluting stents, primarily due to growth inhibition of coronary artery smooth muscle cells (CASMC) across a wide dose range. In this study, we compared the effects of PTX on CASMC to apoptotic-prone HL60 leukemia cells and apoptotic-reluctant A549 lung cancer cells to assess cell survival mechanisms. In comparison to HL60 and A549 cells, CASMC had a shorter mitotic arrest and a lower mitotic index. While CASMC and A549 cells did not become apoptotic and displayed a multi-nucleated phenotype, HL60 cells showed prolonged mitotic arrest followed by apoptosis. CASMC exiting mitosis were arrested in G1 as MN tetraploid cells, with decreased levels of cyclin B1 and PCNA. CASMC remained metabolically active, becoming permanently arrested as evidenced by increased levels of beta-galactosidase activity. These cells did not demonstrate elevated levels of inflammatory markers. Our findings suggest that a weak mitotic checkpoint or inhibited apoptotic cascade, or a combination of both, determine cell survival following PTX treatment. These in vitro findings suggest a mechanism for the cytostatic activity of PTX in CASMC for the inhibition of restenosis.
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PMID:Cytostatic activity of paclitaxel in coronary artery smooth muscle cells is mediated through transient mitotic arrest followed by permanent post-mitotic arrest: comparison with cancer cells. 1686 92

The expression of heme oxygenase-1 (HO-1), stress-related enzyme, is induced in leukaemia and some cancer tissues, but relatively little is known about the differential pattern of HO-1 expression and proliferation in premalignant lesions of the epithelial oral mucosa. The purpose of this study was to evaluate whether HO-1 expression and proliferation were increased in preneoplastic lesions compared to normal and oral cancer tissues. Immunohistochemical staining was used to examine the expression patterns of HO-1 and proliferating cell nuclear antigen (PCNA) in a series of normal mucosa and mild-to-severe cases of oral epithelial dysplasia (OED) and oral squamous cell carcinoma. Both HO-1 and PCNA are expressed in the basal cells of normal oral mucosa. In patients with OED and carcinoma in situ, immunostaining for PCNA and HO-1 was more intense, and gradually extended into the superficial layers of the mucosa. HO-1 and PCNA expression was correlated with the degree of epithelial dysplasia. Oral squamous cell carcinoma also showed elevated expression of HO-1, but this level was not higher than in severe OED or carcinoma in situ. These results suggest that the up-regulation of HO-1 in premalignant oral lesions is part of an early cytoprotection mechanism against carcinogenesis in the oral mucosa.
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PMID:Upregulation of heme oxygenase-1 in oral epithelial dysplasias. 1827 47


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