AIM:To investigate the effect of zinc protoporphyrin IX on the response of hepatoma cells to cisplatin and the possible mechanism involved.METHODS:Cytotoxicity was determined using the3-(4,5-dimethylthiazol-2-yl)-2,5-...AIM:To investigate the effect of zinc protoporphyrin IX on the response of hepatoma cells to cisplatin and the possible mechanism involved.METHODS:Cytotoxicity was determined using the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was determined by a flow cytometric assay.Western blotting was used to measure protein expression.Heme oxygenase(HO)-1 activity was measured by determining the level of bilirubin generated in isolated microsomes.Reactive oxygen species(ROS)production was monitored by flow cytometry.Caspase-3 activity was measured with a colorimetric assay kit.Mice were inoculated with 1×107 tumor cells subcutaneously into the right flanks.All mice were sacrificed 6 wk after the first treatment and tumors were weighed and measured.RESULTS:Overexpression of HO-1 in HepG2 cell line was associated with increased chemoresistance to cisdiaminedichloroplatinum(cisplatin;CDDP)compared to other cell lines in vitro.Inhibition of HO-1 expression or activity by zinc protoporphyrin IX(ZnPP IX)markedly augmented CDDP-mediated cytotoxicity towards all liver cancer cell lines in vitro and in vivo.In contrast,induction of HO-1 with hemin increased resistance of tumor cells to CDDP-mediated cytotoxicity in vitro and in vivo.Furthermore,cells treated with ZnPP IX plus CDDP exhibited marked production of intracellular ROS and caspase-3 activity,which paralleled the incidence of cell apoptosis,whereas hemin decreased cellular ROS and caspase-3 activity induced by CDDP.CONCLUSION:ZnPP IX increases cellular sensitivity and susceptibility of liver cancer cell lines to CDDP and this may represent a mechanism of increasing ROS.展开更多
The leukaemia cells HL60, incubated in 10 mM/ml ALA (5-aminolevulinic) for 4 hours, were carried an experimental research with fluorescent probes in photodynamic therapy (PDT) based on ALA by using PDT reaction room (...The leukaemia cells HL60, incubated in 10 mM/ml ALA (5-aminolevulinic) for 4 hours, were carried an experimental research with fluorescent probes in photodynamic therapy (PDT) based on ALA by using PDT reaction room (The average fluence rate of the 412 nm source was 5 mW/cm2). Cells viability were determined using a Cell Counting Kit-8 (CCK-8) assay, and PpIX Photobleaching of subcellular distributed sites of HL60 cells in vitro were investigated by fluorescence spectra acquired during treatment. The results showed that the fluorescence intensity of mitochondria, lysosomes, endoplasmic reticulum had decreased by 81.5%, 52.3% and 21.0%, respectively, compared with their initial values after a 45-minute light treatment. The rate of PpIX photobleaching in mitochondria was significantly higher than others. Addi-tionally, the change of the activity of HL60 cells was basically characterized by the change fluorescence intensity in mitochondria, which suggest that mitochondria is one of main therapeutic targets of photodynamic therapy.展开更多
Protoporphyrin IX (PPIX) fluorescence-guided brain tumor resection, using 5-aminolevulinic acid (5-ALA), is among the most valuable tools for determining tumor removal area. However, PPIX fluorescence is not necessari...Protoporphyrin IX (PPIX) fluorescence-guided brain tumor resection, using 5-aminolevulinic acid (5-ALA), is among the most valuable tools for determining tumor removal area. However, PPIX fluorescence is not necessarily achieved during an operation visually even when 5-ALA is used, and we do not know until tumor exposure to the excitation light of the ultraviolet region whether PPIX fluorescence has been achieved. When a particular biopsy and frozen section diagnosis is made, the reason for lack of PPIX fluorescence in the tissue cannot be judged. We do not know whether the tumor fails to fluoresce or no fluorescence is seen because it is not the main body of the tumor. We investigated whether the presence or absence of tumor fluorescence could be predicted by examining urinary porphyrin before surgery, at the time of intraoperative fluorescence diagnosis using 5-ALA. The urine of brain tumor patients 2 hours after 5-ALA administration was irradiated with a 405 ± 1 nm laser light. The patients were divided into a fluorescent urine group and negative fluorescent urine group. Red fluorescence was observed in response to the 405 ± 1 nm laser beam for all tumors in the fluorescent urine group. Clear red fluorescence was not observed even with 405 ± 1 nm laser beam irradiation in any tumors in the negative fluorescent urine group. Preoperative prediction of the intraoperative fluorescence of PPIX can be achieved by observation of urine 2 hours after 5-ALA administration with exposure to a 405 ± 1 nm laser light.展开更多
Protoporphyirin-IX (PP-IX) is a precursor of the biosynthesis of the hemo group, most of the cytochromes and the chlorophylls. The PP-IX is used for medical purposes, and recently a report indicated that it exhibits a...Protoporphyirin-IX (PP-IX) is a precursor of the biosynthesis of the hemo group, most of the cytochromes and the chlorophylls. The PP-IX is used for medical purposes, and recently a report indicated that it exhibits a dual action since it can decrease or increase the genetic damage caused by N-nitroso-N-ethylurea (ENU) in somatic cells of Drosophila. PP-IX is known to be able to act as an anti-or pro-oxidant agent. The aim of the present research was to study the role of PP-IX on the lifespan of Drosophila melanogaster, taking into account the fact that increasing levels of ROS can accelerate the aging process. The Canton-S strain (CS) was used as well as Sod and Cat which are deficient in the endogenous enzymes, superoxide dismutase and catalase, respectively. Groups of females and males were treated separately with 5 mg/ml of PP-IX solution. The comparison of survival curves indicates that this pigment extended the lifespan of CS. In contrast, Sod strain showed that the opposite effect and had no effect in Cat strain. The fact that PP-IX reduces the mean lifespan in Sod deficient strain might suggest a pro-oxidant action of PP-IX, and consequently the cumulating of ROS as a superoxide could have a mutagenic effect as was shown recently. The results presented evidence of the dual effect of PP-IX.展开更多
基金Supported by Xuzhou City Health Bureau Project,China,No.XZZD1128Xuzhou City Municipal Science and Technology Bureau Project,China,No.XWJ2011040
文摘AIM:To investigate the effect of zinc protoporphyrin IX on the response of hepatoma cells to cisplatin and the possible mechanism involved.METHODS:Cytotoxicity was determined using the3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Apoptosis was determined by a flow cytometric assay.Western blotting was used to measure protein expression.Heme oxygenase(HO)-1 activity was measured by determining the level of bilirubin generated in isolated microsomes.Reactive oxygen species(ROS)production was monitored by flow cytometry.Caspase-3 activity was measured with a colorimetric assay kit.Mice were inoculated with 1×107 tumor cells subcutaneously into the right flanks.All mice were sacrificed 6 wk after the first treatment and tumors were weighed and measured.RESULTS:Overexpression of HO-1 in HepG2 cell line was associated with increased chemoresistance to cisdiaminedichloroplatinum(cisplatin;CDDP)compared to other cell lines in vitro.Inhibition of HO-1 expression or activity by zinc protoporphyrin IX(ZnPP IX)markedly augmented CDDP-mediated cytotoxicity towards all liver cancer cell lines in vitro and in vivo.In contrast,induction of HO-1 with hemin increased resistance of tumor cells to CDDP-mediated cytotoxicity in vitro and in vivo.Furthermore,cells treated with ZnPP IX plus CDDP exhibited marked production of intracellular ROS and caspase-3 activity,which paralleled the incidence of cell apoptosis,whereas hemin decreased cellular ROS and caspase-3 activity induced by CDDP.CONCLUSION:ZnPP IX increases cellular sensitivity and susceptibility of liver cancer cell lines to CDDP and this may represent a mechanism of increasing ROS.
文摘The leukaemia cells HL60, incubated in 10 mM/ml ALA (5-aminolevulinic) for 4 hours, were carried an experimental research with fluorescent probes in photodynamic therapy (PDT) based on ALA by using PDT reaction room (The average fluence rate of the 412 nm source was 5 mW/cm2). Cells viability were determined using a Cell Counting Kit-8 (CCK-8) assay, and PpIX Photobleaching of subcellular distributed sites of HL60 cells in vitro were investigated by fluorescence spectra acquired during treatment. The results showed that the fluorescence intensity of mitochondria, lysosomes, endoplasmic reticulum had decreased by 81.5%, 52.3% and 21.0%, respectively, compared with their initial values after a 45-minute light treatment. The rate of PpIX photobleaching in mitochondria was significantly higher than others. Addi-tionally, the change of the activity of HL60 cells was basically characterized by the change fluorescence intensity in mitochondria, which suggest that mitochondria is one of main therapeutic targets of photodynamic therapy.
文摘Protoporphyrin IX (PPIX) fluorescence-guided brain tumor resection, using 5-aminolevulinic acid (5-ALA), is among the most valuable tools for determining tumor removal area. However, PPIX fluorescence is not necessarily achieved during an operation visually even when 5-ALA is used, and we do not know until tumor exposure to the excitation light of the ultraviolet region whether PPIX fluorescence has been achieved. When a particular biopsy and frozen section diagnosis is made, the reason for lack of PPIX fluorescence in the tissue cannot be judged. We do not know whether the tumor fails to fluoresce or no fluorescence is seen because it is not the main body of the tumor. We investigated whether the presence or absence of tumor fluorescence could be predicted by examining urinary porphyrin before surgery, at the time of intraoperative fluorescence diagnosis using 5-ALA. The urine of brain tumor patients 2 hours after 5-ALA administration was irradiated with a 405 ± 1 nm laser light. The patients were divided into a fluorescent urine group and negative fluorescent urine group. Red fluorescence was observed in response to the 405 ± 1 nm laser beam for all tumors in the fluorescent urine group. Clear red fluorescence was not observed even with 405 ± 1 nm laser beam irradiation in any tumors in the negative fluorescent urine group. Preoperative prediction of the intraoperative fluorescence of PPIX can be achieved by observation of urine 2 hours after 5-ALA administration with exposure to a 405 ± 1 nm laser light.
文摘Protoporphyirin-IX (PP-IX) is a precursor of the biosynthesis of the hemo group, most of the cytochromes and the chlorophylls. The PP-IX is used for medical purposes, and recently a report indicated that it exhibits a dual action since it can decrease or increase the genetic damage caused by N-nitroso-N-ethylurea (ENU) in somatic cells of Drosophila. PP-IX is known to be able to act as an anti-or pro-oxidant agent. The aim of the present research was to study the role of PP-IX on the lifespan of Drosophila melanogaster, taking into account the fact that increasing levels of ROS can accelerate the aging process. The Canton-S strain (CS) was used as well as Sod and Cat which are deficient in the endogenous enzymes, superoxide dismutase and catalase, respectively. Groups of females and males were treated separately with 5 mg/ml of PP-IX solution. The comparison of survival curves indicates that this pigment extended the lifespan of CS. In contrast, Sod strain showed that the opposite effect and had no effect in Cat strain. The fact that PP-IX reduces the mean lifespan in Sod deficient strain might suggest a pro-oxidant action of PP-IX, and consequently the cumulating of ROS as a superoxide could have a mutagenic effect as was shown recently. The results presented evidence of the dual effect of PP-IX.
