Peroxidase Activity May Play a Role in the Cytotoxic Effect of Indole Acetic Acid*

Melo, Mariza Pires de; Curi, Tânia Cristina Pithon; Curl, Rui; Mascio, Paolo Di; Cilento, Giuseppe

doi:10.1111/j.1751-1097.1997.tb08567.x

Cited by 29 publications

(29 citation statements)

References 15 publications

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“…injection of 20 ml sterile oyster glycogen solution (Sigma, Type II) at 1% in PBS. 13,14 The same procedure was used for preparation of monocytes but in this case the rats were injected i.p. with 3 ml sterile thioglycollate solution (4%), 4 days prior to the harvest of the cells.…”

Section: Leukocyte Preparationmentioning

confidence: 99%

“…with 3 ml sterile thioglycollate solution (4%), 4 days prior to the harvest of the cells. 13 Monocytes were obtained by lavage with 40 ml sterile PBS of the i.p. cavity of the rats.…”

Section: Leukocyte Preparationmentioning

confidence: 99%

“…Lymphocytes were isolated from mesenteric lymph nodes as previously described. 13,14 The cell suspensions were centrifuged (850 g for 8 min) three times in PBS. The number of viable cells, (always > 95%), was counted in a Neubauer chamber using a light microscope (Nikkon, Japan), and Trypan Blue solution at 1%.…”

Section: Leukocyte Preparationmentioning

confidence: 99%

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Glucose and glutamine utilization by rat lymphocytes, monocytes and neutrophils in culture: a comparative study

Pithon-Curi

Melo

Curi

2004

Cell Biochemistry & Function

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Glucose and glutamine utilization and production of glutamate and lactate were determined for up to 48 h in lymphocytes, monocytes and neutrophils cultured in medium rich in metabolites and vitamins. Glucose was utilized by the three cell types in culture in the following order: neutrophils > monocytes > lymphocytes, whereas lactate was produced in the order: monocytes > neutrophils > lymphocytes. The consumption of glucose followed the activity of glucose-6-phosphate dehydrogenase but it was not related to hexokinase activity. Glutamine was consumed by the three leukocyte types in culture as follows: neutrophils > lymphocytes > or = monocytes. The consumption of glutamine was not fully related to the activity of phosphate-dependent glutaminase. The production of glutamate was not remarkably different among the three cell types. For comparison, glutamine and glucose utilization and glutamate and lactate production were also evaluated using 1-h incubated leukocytes. Under this condition, only glucose or glutamine was added to the medium. Glucose was utilized as follows: neutrophils > monocytes > lymphocytes, whereas lactate was produced in the following order: monocytes > or = neutrophils > lymphocytes. Glutamine was consumed as follows: neutrophils > lymphocytes > monocytes, whereas glutamate was produced as follows: neutrophils > or = monocytes = lymphocytes. The ratio of the amount of glucose/glutamine consumed by 1-h incubated cells was 0.5 for neutrophils, 1.5 for monocytes, and 0.3 for lymphocytes. However, the three cell types cultured for 48 h utilized glucose to a much higher degree than glutamine. The ratio of the amount of glucose/glutamine utilized by the cultured cells was 8.9 for neutrophils, 16.4 for monocytes, and 6.7 for lymphocytes. These observations support the proposition that glutamine is required in much higher amounts than glucose to accomplish the total metabolic requirement of leukocytes. Under conditions closer to physiological when the availability of a variety of metabolites and vitamins is not restricted, glucose is the preferred substrate for lymphocytes, monocytes and neutrophils.

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Section: Leukocyte Preparationmentioning

confidence: 99%

“…with 3 ml sterile thioglycollate solution (4%), 4 days prior to the harvest of the cells. 13 Monocytes were obtained by lavage with 40 ml sterile PBS of the i.p. cavity of the rats.…”

Section: Leukocyte Preparationmentioning

confidence: 99%

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Glucose and glutamine utilization by rat lymphocytes, monocytes and neutrophils in culture: a comparative study

Pithon-Curi

Melo

Curi

2004

Cell Biochemistry & Function

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“…15 Horseradish peroxidase isozyme C (HRPC) oxidizes IAA to produce free radicals that are cytotoxic to mammalian cells. [16][17][18][19] IAA or HRP alone shows no cytotoxic effect in mammalian cells. Only the combination of these two compounds can result in cell death.…”

Section: Introductionmentioning

confidence: 95%

“…Only the combination of these two compounds can result in cell death. [16][17][18][19] One strategy to selectively induce tumor cell death and avoid damage to normal tissues is to target HRP on tumor cells for producing the toxic IAA metabolites. As the high level of alpha-fetoprotein (AFP) is expressed in liver tumor cells, but not in adult normal liver cells, 20,21 AFP has been chosen as a promoter for liver tumor-targeted gene delivery.…”

Section: Introductionmentioning

confidence: 99%

Tumor-targeted gene therapy using Adv-AFP-HRPC/IAA prodrug system suppresses growth of hepatoma xenografted in mice

et al. 2011

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Clinical efficacy of current therapies for hepatocellular carcinoma (HCC) treatment is limited. Indole-3-acetic acid (IAA) is non-toxic for mammalian cells. Oxidative decarboxylation of IAA by horseradish peroxidase (HRP) leads to toxic effects of IAA. The purpose of this study was to investigate the effects of a novel gene-targeted enzyme prodrug therapy with IAA on hepatoma growth in vitro and in vivo mouse hepatoma models. We generated a plasmid using adenovirus to express HRP isoenzyme C (HRPC) with the HCC marker, alpha-fetoprotein (AFP), as the promoter (pAdv-AFP-HRPC). Hepatocellular cells were infected with pAdv-AFP-HRPC and treated with IAA. Cell death was detected using MTT assay. Hepatoma xenografts were developed in mice by injection of mouse hepatoma cells. The size and weight of tumors and organs were evaluated. Cell death in tumors was assessed using hematoxylin and eosin-stained tissue sections. HRPC expression in tissues was detected using Reverse Transcriptase-Polymerase Chain Reaction. IAA stimulated death of hepatocellular cells infected with pAdv-AFP-HRPC, in a dose-and time-dependent manner, but not in control cells. Growth of hepatoma xenografts, including the size and weight, was inhibited in mice treated with pAdv-AFP-HRPC and IAA, compared with that in control group. pAdv-AFP-HRPC/IAA treatment induced cell death in hepatoma xenografts in mice. HRPC gene expressed only in hepatoma, but not in other normal organs of mice. pAdv-AFP-HRPC/IAA treatment did not cause any side effects on normal organs. These findings suggest that pAdv-AFP-HRPC/IAA enzyme/prodrug system may serve as a strategy for HCC therapy.

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Percentage of phagocytosis, production of O2·−, H2O2 and NO, and antioxidant enzyme activities of rat neutrophils in culture

Curi

Melo

Palanch

et al. 1998

Cell Biochem. Funct.

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Changes in the integrity, ultrastructure, phagocytosis capacity, and production of H2O2, O2.- and NO2- were evaluated in cultured neutrophils. The activities of the antioxidant enzymes (catalase-CAT, superoxide dismutase-SOD and glutathione-dependent peroxidase-GSH-Px) were measured under similar conditions. The integrity of the cells remained unchanged up to 18 h. After 24 h, the number of viable cells in culture dropped by 16 per cent. The percentage of viable cells in culture was of 72 per cent even after 72 h. An ultrastructural analysis of the cells was carried out after 3, 6, 12, 24, 48, and 72 h in culture. Neutrophils started developing morphologic changes after 24 h: decreased cell volume, abundant vacuoles (mainly around the nucleus), and also the presence of autophagic vacuoles. This period was then chosen for the study of neutrophil function and antioxidant enzyme activities. Neutrophils cultured for 24 h presented reduced phagocytosis capacity. The rates of production of H2O2 and O2.- remained unchanged after 24 h in culture. Concomitantly, these cells were also able to produce NO in significant amounts. The production of O2.- in response to PMA stimulus was lowered in 24-h cultured cells. Possibly, the production of oxygen and nitrogen reactive species accomplished with a decrease in the activities of CAT and GSH-Px play a key role for the process of apoptosis which takes place in neutrophils under these conditions.

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Peroxidase Activity May Play a Role in the Cytotoxic Effect of Indole Acetic Acid*

Cited by 29 publications

References 15 publications

Glucose and glutamine utilization by rat lymphocytes, monocytes and neutrophils in culture: a comparative study

Glucose and glutamine utilization by rat lymphocytes, monocytes and neutrophils in culture: a comparative study

Tumor-targeted gene therapy using Adv-AFP-HRPC/IAA prodrug system suppresses growth of hepatoma xenografted in mice

Percentage of phagocytosis, production of O2·−, H2O2 and NO, and antioxidant enzyme activities of rat neutrophils in culture

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