Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.1.21 (thymidine kinase)
7,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have recently described the partial purification and characterization of a neutrophil migration inhibitory activity present in serum from patients with chronic lymphocytic leukaemia (CLL). This new lymphokine, the chemokinetic inhibitory factor (CIF), is produced by B-CLL cells. It is a heat-labile glycoprotein of an approximate molecular weight (m. w.) of 30000. In this extended investigation 64/89 CLL-patients had CIF in their serum. CLL serum diluted to a concentration of 0.02% gave significantly decreased chemokinetic activity, suggesting that CIF is potent at very low concentrations. 31/89 patients had increased infection propensity. Significantly more patients with CIF in serum had infections compared to the group with normal susceptibility to infections. The combination of low Ig levels and CIF in serum discriminated even better between the infection-prone and non-infection-prone patients. CIF in serum was not correlated to tumour cell mass - estimated by Rai clinical staging - tumour progression or deoxythymidine kinase, S-TK, an enzyme that may reflect proliferating cells. The existence of this new lymphokine in serum seems to contribute to the increased susceptibility to infections seen in CLL patients.
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PMID:The chemokinetic inhibitory factor (CIF) in serum of CLL patients: correlation with infection propensity and disease activity. 390 Dec 43

The cellular levels of the purine catabolic enzymes adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) and those for the pyrimidine activities thymidine phosphorylase and thymidine kinase isozymes have been measured concurrently in peripheral blood nucleated cells of patients with acute lymphoblastic leukaemia, chronic lymphocytic or prolymphocytic leukaemia and correlated with the spontaneous tritiated thymidine uptake of the isolated cells. Highest ADA levels occurred in T-ALL cells but considerable overlap of individual activities occurred for non-T, non-BALL, B-CLL and T-CLL cells. The levels of PNP showed no distinct discriminatory trend in cells of the lymphoid proliferative disorders examined. Thymidine phosphorylase activity was markedly reduced in T-ALL and T-CLL cells with a stepwise increase in the level of mean activities for non-T, non-B ALL, B-CLL and B-PLL cells to that of isolated normal peripheral blood lymphocytes. Spontaneous tritiated thymidine uptake of the abnormal lymphoid cells exhibited a correlation between cellular thymidine kinase isozyme 1 and elevated ADA levels. The use of ADA inhibitors together with thymidine infusion for the treatment of lymphoproliferative disorders is discussed.
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PMID:Purine and pyrimidine activities in acute and chronic lymphocytic leukaemia: relation to cellular proliferative status. 681 8

Deoxynucleoside kinases are key enzymes in deoxyribonucleoside salvage, activating several clinically important chemotherapeutic drugs. The four known kinases, cytosolic thymidine kinase (TK1) and deoxycytidine kinase (dCK) and the mitochondrial thymidine kinase (TK2) and deoxyguanosine kinase (dGK), have been purified and characterized as to the subunit structure as well as specificity with a large number of analogs. These results are summarized and used to establish selective assays for the four enzymes in crude extracts of normal and malignant human peripheral blood mononuclear cells, gastrointestinal tissues and sarcomas. TK2 and dGK activities were found at low levels in all tissues, possibly correlated to the content of mitochondria. TK1 activity was detected only in samples containing a significant number of S phase cells. We have measured dCK activity as well as dCK polypeptide level by immuno blotting in these extracts. High levels of dCK were found in normal mononuclear leukocytes (91-145 ng dCK/mg protein) and in B-cell chronic lymphocytic leukemia (80 +/- 30 ng/mg, n = 23). Hairy cell leukemia contained lower levels (28 +/- 23 ng/mg, n = 7), as did unexpectedly three samples of T-cell chronic lymphocytic leukemia (18 +/- 14 ng/mg). Phytohemaglutinine stimulation of normal lymphocytes did not lead to any substantial increase in either dCK activity or expression (less than 2.5-fold). In colon adenocarcinomas, the dCK content was significantly higher (21 +/- 9.3 ng/mg, n = 20) than in normal colon mucosa (8.2 +/- 3.7 ng/mg, n = 19, p < 0.05). A similar pattern of dCK expression was found in gastric adenocarcinomas (21 +/- 13 ng/mg, n = 5) and normal ventricular mucosa (6.2 +/- 5.4 ng/mg, n = 5, p < 0.15). One leiomyosarcoma and one extra-skeletal osteosarcoma showed a dCK levels comparable to those found in normal lymphocytes (84 +/- 6 and 109 +/- 4 ng/mg), while other sarcoma samples contained levels comparable to the gastrointestinal adenocarcinomas (20 +/- 7 ng/mg, n = 12). We confirm that dCK is expressed constitutively and predominantly in lymphoid cells, but conclude that a significant expression may be found in non-lymphoid tissues as well, with increased levels in the corresponding tumor tissue. 2-Chlorodeoxyadenosine (CdA), an antileukemic agent used in treatment of hairy cell leukemia and chronic lymphocytic leukemias (B-CLL), is phosphorylated by dCK which was used as the selective substrate for this enzyme. A study was performed to investigate if there was a correlation between the dCK levels and the response to CdA treatment.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Properties and levels of deoxynucleoside kinases in normal and tumor cells; implications for chemotherapy. 794 71

The serum levels of soluble intercellular adhesion molecule 1 (ICAM-1) were significantly elevated (P < .001) in patients with chronic B-lymphocytic leukemia (B-CLL, n = 113) compared with healthy controls (n = 31). sICAM-1 levels in B-CLL were positively correlated to the tumor mass as reflected by the modified Rai and the Binet staging systems, lymphocyte counts, and isolated spleno/hepatomegaly. During disease progression or regression on cytoreductive therapy, the circulating sICAM-1 levels changed accordingly. sICAM-1 was also correlated to a kinetic parameter such as the lymphocyte doubling time. Furthermore, the serum sICAM-1 levels were inversely correlated to hemoglobin levels in patients with early clinical stage, and this may turn out to be of prognostic value. sICAM-1 was compared with other serum markers said to reflect disease activity in B-CLL, ie, soluble CD23, thymidine kinase, lactate dehydrogenase (LDH), and beta 2-microglobulin. sICAM-1 was equally well or better correlated to clinical stage and lymphocyte doubling time. In univariate regression analysis, all serum markers but LDH correlated with survival, and in multivariate analysis, sICAM-1 was the only marker approaching significance for additional prognostic information when included after clinical stage and lymphocyte doubling time. Based on the present observations, it appears that prospective studies repeatedly monitoring serum sICAM-1 in B-CLL are justified.
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PMID:Serum levels of soluble intercellular adhesion molecule 1 are increased in chronic B-lymphocytic leukemia and correlate with clinical stage and prognostic markers. 777 31

The efficacy of interferon-alpha 2b (IFN alpha) to prolong progression-free (PFS) and/or overall survival (OS) in early B-CLL (Binet stage A) was examined in a risk-adapted phase III study. 99 previously untreated B-CLL patients were recruited. 44 patients with expected high risk for disease progression, defined by non-nodular bone marrow infiltration and lymphocyte doubling time < or = 12 months or serum thymidine kinase levels > or = 5 U/I, were randomized to either receive IFN alpha (group 1, n = 21) or not (group 2, n = 23). 55 low-risk patients were observed to evaluate this risk stratification (group 3). During a median observation time of 36 months, four patients in the IFN alpha group achieved a partial remission (PR), no patient had stable disease (SD), and 17 patients experienced progressive disease (PD). The four responders had less extensive disease at study entry and tended to exhibit a rise in serum IgG levels. In group 2, no PR, seven SD and 16 PD, whereas in group 3, no PR, 37 SD and 18 PD occurred. PFS in group 1 (6.7 months) was not different from group 2 (13.3 months, P = 0.22), but PFS of groups 1 and 2 differed from group 3 (37 months, P < or = 0.001). OS was 44.9 months (group 1), 43.1 months (group 2) and 57.9 months (group 3). OS was not significantly different for group 1 v 2, but was significant between groups 1 and 3 (P = 0.023). The higher percentage of PD in group 2 compared to group 3 (70% v 29%) shows that the selected risk factors allow the definition of CLL stage A patients at risk for disease progression within about a year. In conclusion, our data indicate that IFN alpha does not prolong PFS or OS in stage A CLL patients with high risk for disease progression.
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PMID:Interferon-alpha 2b (IFN alpha) for early-phase chronic lymphocytic leukaemia with high risk for disease progression: results of a randomized multicentre study. 875 97

Inhibition of bcl-2 expression by antisense oligodeoxynucleotides (ODN) might render bcl-2 overexpressing malignant B cells more susceptible to chemotherapy. ODN containing unmethylated CG dinucleotides (CpG) are known to activate B cells. We studied the effects of two bcl-2 antisense ODN, with (G3139) or without CG dinucleotides (NOV 2009) within the sequence, and the effects of a nonantisense, CpG-containing ODN (ODN 2006) on activation and apoptosis of malignant B cell lines and primary B-CLL cells. Without cationic lipids, no antisense-mediated inhibition of bcl-2 synthesis was achieved with G3139 and NOV 2009. Instead, G3139, but not NOV 2009, induced similar changes as ODN 2006 in proliferation, expression of costimulatory and antigen-presenting molecules, as well as in bcl-2 and bcl-xL levels of primary B-CLL cells. G3139 and ODN 2006 inhibited in vitro, spontaneous apoptosis in B-CLL cells of patients with high serum thymidine kinase activity (s-TK, marker for proliferative activity of malignant B cells), whereas in patients with low s-TK activity, apoptosis was induced. In conclusion, our results suggest that modulation of malignant B cell apoptosis by G3139 depends on its immunostimulatory properties rather than on antisense-mediated reduction of bcl-2 expression. Immunostimulatory CpG ODN may have a therapeutic potential in patients with B-CLL, especially those with low s-TK activity.
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PMID:Modulation of malignant B cell activation and apoptosis by bcl-2 antisense ODN and immunostimulatory CpG ODN. 1210 Dec 66

In B-CLL IgV(H) genes mutational status is a major prognostic factor. Since sequencing of IgV(H) genes is not available in most laboratories, an easily performed surrogate assay is desirable. To identify the best surrogate assay, and to better discriminate prognostic subgroups we analyzed clinical and biological data from 58 typical CLL cases. A higher serum thymidine kinase level (>15 U/l) proved to be a strong predictor of mutational status, and the only independent one among the studied parameters. To further identify prognostic subgroups, cluster analysis was employed on 38 cases on which all data were available, which segregated two groups including 25 and 13 patients, respectively. These two clusters differed by their proliferative potential and appeared to discriminate patients with very different clinical course and outcome. s-TK was strikingly different among these two clusters, suggesting that s-TK level could be used routinely to identify patients at risk of progression.
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PMID:Predictive value of serum thymidine kinase level for Ig-V mutational status in B-CLL. 1252 70

Deoxycytidine kinase (dCK), a key enzyme of the deoxynucleoside salvage pathway, might have a preponderant role in DNA synthesis in resting chronic lymphocytic leukemia B-lymphocytes. In these cells, two important enzymes in deoxynucleoside triphosphate production, ribonucleotide reductase and thymidine kinase (TK), both cell-cycle regulated, are indeed very weakly expressed. This study investigated the regulation of dCK activity in response to UV-C light, a condition which causes DNA lesions and DNA repair synthesis. We observed that activity of dCK in B-CLL cells was upregulated up to 3-fold, 30 min after irradiation with 30 J/m(2) UV-C, whereas TK activity was unchanged. Activation of dCK by UV-C light was caused neither by a change in concentration of a low molecular weight metabolite nor by an increase in the amount of dCK protein. Activation of dCK by UV-C was mimicked by H(2)O(2), markedly counteracted by N-acetylcysteine, a general antioxidant, and completely abolished by the growth factor receptor inhibitor suramin. Taken together, these results indicate that dCK activity is upregulated by UV-C light through a postranslational modification that may be initiated at the cell surface through oxidative mechanisms. Suramin also suppressed the increase in DNA repair synthesis elicited by UV-C irradiation, suggesting that upregulation of dCK activity could contribute to the normal completion of DNA repair synthesis elicited by UV light.
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PMID:Activation of deoxycytidine kinase by UV-C-irradiation in chronic lymphocytic leukemia B-lymphocytes. 1256 84

A C825T polymorphism has been described in the GNB3 gene which encodes the Gbeta3 subunit of heterotrimeric G proteins. The GNB3 825T allele is predictive of enhanced Gi protein activation. This study was performed to correlate genotypes of the C825T polymorphism with various clinical aspects of chronic lymphocytic leukaemia (B-CLL). The GNB3 genotype distribution in B-CLL patients was similar to that in other Caucasian populations, arguing against a role of the polymorphism in the susceptibility to develop B-CLL. No statistically significant differences were observed at diagnosis between patients with the CC genotype and homozygous or heterozygous T allele carriers with respect to age at disease onset, sex distribution, proportion of patients with CD38+ leukaemia or patients in Binet stage A, blood cell counts, degree of bone marrow infiltration or serum levels of lactate dehydrogenase, thymidine kinase or beta2-microglobulin. In a subgroup of 44 patients requiring chemotherapy, the median interval between diagnosis and first treatment and the response to treatment were similar in patients with CC or CT/TT genotypes. A statistically significant difference, however, was found in the proportion of patients relapsing and requiring second line chemotherapy (CC: 95%; CT/TT: 52%; p = 0.0043). The GNB3 genotype (p = 0.024) and age (p = 0.042) were identified as independent prognostic factors for a second therapy. Thus, the long-term success of the treatment appears to be correlated with the GNB3 genotype.
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PMID:The CC genotype of the C825T polymorphism of the G protein beta3 gene (GNB3) is associated with a high relapse rate in patients with chronic lymphocytic leukaemia. 1469 27

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