Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.1.1 (hexokinase)
 5,274 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A pH-dependent, saturable binding of hexokinase isozyme I from Ehrlich ascites carcinoma to plasma membrane and microsome preparations from the same tissue is demonstrated. This binding is enhanced by glucose 6-phosphate and may be considered as the sum of a glucose 6-phosphate-dependent binding and an independent binding. The half saturation concentration of hexokinase is about 0.4 unit per ml for both types of binding, and a maximal binding of 0.5-2.0 units per mg membrane protein is observed for both, although the pH optimum of the independent binding (5.4) is lower than that of the dependent binding (5.9). The half saturation concentration of glucose 6-phosphate required for the dependent binding is 0.05 mM at pH 6.1. 2-Deoxyglucose 6-phosphate competatively reverses the effect of glucose 6-phosphate on binding but does not diminish its inhibition of hexokinase activity.
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PMID:Glucose 6-phosphate-dependent binding of hexokinase to membranes of ascites tumor cells. 1 34

The R3230AC mammary adenocarcinoma was not dependent on insulin; tumor growth was equal to or greater in diabetic rats than in intact animals. However, tumor growth was reduced when daily doses of insulin were administered. Treatment with estrogen inhibited growth of the R3230AC carcinoma, either in diabetic rats or in intact animals simultaneously treated with insulin. The effects of insulin plus estrogen treatment appeared to be additive in causing inhibition of tumor growth. Tumors from diabetic rats showed few metabolic alterations as reflected by little or no changes in the activities of selected glycolytic enzymes, pyruvate kinase, phosphofructokinase, and hexokinase, nor any striking changes in the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase, representing the pentose phosphate pathway. A modest reduction in the ratio of utilization of (1-14C)glucose: (6-14C)glucose was seen in vitro by tumors from diabetic rats. It was concluded that insulin, along with estrogen and prolactin, should be considered as a hormonal factor that influences growth of this automonous, hormone-responsive adenocarcinoma.
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PMID:Influence of insulin on estrogen-induced responses in the r3230ac mammary carcinoma. 12 68

The activity of the following enzymes was studied in normal, precancerous, and malignant biopsies from the human cervix uteri: hexokinase (HK), phosphofructokinase (PFK), pyruvate-kinase (PK), lactate dehydrogenase (LDH), and glucose-6-phosphate dehydrogenase (G-6-PDH). In precancerous conditions, i.e., dysplasia and carcinoma in situ without any signs of invasive carcinoma, only PK showed moderate but significant activity increases. A rise in enzyme activity in biopsies histologically classified as carcinoma in situ was found to signal the presence of invasive carcinoma in other parts of the cervix. In invasive carcinomas of the cervix, all the enzymes studied showed a two- to four-fold increase (p less than 0.01) as compared to the normal cervix. The present study failed to reveal significant differences between enzyme activities in biopsies from patients in Stage I, II, and III; no correlation could be established between enzyme activity and prognosis.
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PMID:The glycolytic enzyme activity of the human cervix uteri. 16 34

Activities of some enzymes associated with carbohydrate and lipid metabolism were determined in 48 human breast carcinomas and compared with those found in 35 nonmalignant breast tumours and also in 13 normal breast tissues. In fibrocystic disease only the activity of citrate lyase was markedly higher (14-fold) than in normal tissue. The activities of the remaining enzymes did not differ significantly from those in normal tissue. Enzyme activities in breast carcinoma were 4--160 x those determined in normal tissue according to the following sequence : phosphofructokinase less than malate NADP dehydrogenase less than hexokinase less than lactate dehydrogenase less than isocitrate NADP dehydrogenase less than ATP citrate lyase. Activity of citrate lyase, very low in normal breast (0.0017 mumol/min/g of tissue) rose gradually to 0.039, 0.072 and 0.258 mumol/min/g of tissue in localized fibrocystic disease, fibroadenomas and carcinomas respectively. These data support the idea that citrate lyase may play an important role in lipogenesis in hyperplastic human breast tissues.
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PMID:Lipogenetic and glycolytic enzyme activities in carcinoma and nonmalignant diseases of the human breast. 44 7

Catalytic properties and isoenzyme composition of hexokinase were studied in extracts of normal thyroid, thyroid benign adenoma and thyroid carcinoma tissues from 23 patients. It was shown that the "cancer" hexokinase was several times more active and had lower Km (glucose) as compared with the enzyme from normal thyroid and benign tumor. Gel electrophoretic study revealed five hexokinase isoenzymes in both normal thyroid and its benign tumor. The hexokinase isoenzyme pattern in thyroid carcinoma was characterized by the "deletion" or distinctly decreased ratio of the "slowest" component. Studies on catalytic properties and isoenzyme composition of hexokinase are important as an additional test for the differentiation between benign and malignant tumors.
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PMID:[Catalytic properties and isoenzyme composition of hexokinase in thyroid gland normal and neoplastic tissue]. 75 96

The activities of hexokinase, phosphofructokinase, aldolase, enolase and pyruvate kinase were studied in breast cancer tissues, in comparison to benign breast disease and normal breast tissues. The enzyme activities in breast cancer were significantly increased compared to normal and benign breast tissues (p less than 0.001). Also the increase in activity in benign disease compared to normal was statistically significant (p less than 0.001). Within the group of benign diseases, fibroadenomas could be distinguished from fibrocystic disease, the former generally showing higher activities compared to the latter (p less than or equal to 0.05). Carcinoma subgroups, classified according to their histology, could not be recognized enzymologically. In addition, isozyme composition of pyruvate kinase and enolase was studied. We did not find a significant shift towards K type pyruvate kinase expression in benign disease compared to normal breast tissues. Also fibroadenomas did not differ from fibrocystic disease. However, the amount of K type pyruvate kinase in carcinomas proved to be significantly higher in comparison to benign disease and normal breast tissues (p less than 0.001). Expression of alpha gamma-enolase in normal breast tissue was virtually absent. In benign disease only a minority of specimens did show the hybrid alpha gamma-enolase. Nearly all carcinomas had alpha gamma-enolase expression and in 20% of the carcinomas gamma gamma-enolase could be detected (so-called neuron-specific enolase). By discriminant analysis, the function giving the best discrimination compared to the histological data was based on natural logarithm aldolase and the total of gamma-enolase subunits. Contrary to expectation, the regulator enzymes of glycolysis; i.e., hexokinase, phosphofructokinase and pyruvate kinase were not included in this discriminant function. The best fit produced a 90% correct classification in both benign and malignant disease. If these findings are confirmed to a larger series, the discrimination is sufficiently strong to form the basis of a clinically useful tool.
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PMID:Glycolytic enzymes in breast cancer, benign breast disease and normal breast tissue. 344 71

Serum levels of phosphohexose isomerase (PHI), aldolase (ALD) and hexokinase (HK) activities have been determined in 76 patients of carcinoma cervix, in search of proper diagnostic and prognostic parameters. All the three glycolytic enzyme levels studied were found to be significantly elevated in all the groups of malignancy and showed a relation to the clinical stage and tumor. Serum PHI levels were of best diagnostic significance even at an early stage of the disease. The enzyme levels correlated well with the prognosis of the disease.
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PMID:Diagnostic and prognostic significance of serum phosphohexose isomerase, aldolase and hexokinase in carcinoma cervix. 381 45

Serum levels of lactate dehydrogenase and its isoenzymes, phosphohexos isomerase, aldolase and hexokinase were determined in 152 cases of breast carcinoma, in search of proper diagnostic and prognostic parameters. The enzyme levels showed a relation to the clinical stage of the tumor and were, on an average, higher in advanced stages of disease. Phosphohexose isomerase and lactate dehydrogenase-isoenzyme levels were of best diagnostic significance even at an early stage of the disease. The enzyme levels correlated well with the prognosis of the disease. In group three, the prognosis was very poor and the patients responded only slightly to the treatment, and only up to the third month; after that enzyme levels again increased.
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PMID:Serum glycolytic enzymes in breast carcinoma. 395 20

Hexokinase (ADP: D-hexose-6-phosphotransferase, EC 2.7.1.1) was studied in human thyroid carcinomas (n = 11), follicular adenomas (n = 32), and normal thyroid tissue (n = 21). The specific activity was significantly increased in carcinoma (0.163 +/- 0.083 U/mg protein) compared with normal tissue (0.030 +/- 0.010 U/mg protein) (P less than 0.001). Specific activities of follicular adenomas are rather heterogeneous, but when subdivided into three groups according to histopathologic criteria, a significant difference was found between follicular adenomas group I and II and follicular adenomas group III. A lesser cellular differentiation of adenomas is indicated by the lower degree or even absence of colloid production and follicle formation. A higher proliferation rate may be assumed on the grounds of the irregularities in outline, the often defective pseudocapsule, and signs of compression of the surrounding tissue. The highest specific activity in adenomas was found in the group with the highest proliferative activity, i.e., group III, whereas the lowest specific activities were found in adenomas with the lowest grade of proliferation, i.e., group I; the former was comparable with values found in carcinomas and the latter was comparable with values found in normal thyroid tissue. An interesting difference was found when the compartmentation of hexokinase was compared in carcinomas of different degree of differentiation. In papillary carcinomas a significantly lower proportion of hexokinase (HK) is present in the cytosol in comparison to follicular and undifferentiated carcinomas. In carcinomas more HK II and less HK I was found in comparison with normal thyroid tissue. In contrast hexokinase isozyme composition and compartmentation in adenomas were not different from normal thyroid tissue.
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PMID:Determination and characterization of hexokinase in thyroid cancer and benign neoplasms. 397 45

The serum phosphohexose isomerase (PHI), aldolase and hexokinase activities have been determined in 36 patients of carcinoma ovary with different clinical stages and in 25 healthy normal female subjects. The serum PHI and hexokinase levels were significantly elevated (P less than .001) in all the stages of malignancy while serum aldolase was significantly elevated only in stages III and IV of malignancy. The enzyme levels showed statistically significant response to therapy in stage II patients. The mean values in patients with progression of the disease were not significantly different.
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PMID:Significance of serum phosphohexose isomerase, hexokinase and aldolase in carcinoma ovary. 405 17


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