Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30536 (PBS)
 9,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A modified highly sensitive procedure for the evaluation of DNA damage in individual cells treated with alkylating agents is reported. The new methodology is based on the amplification of single-strandedness in alkylated DNA by heating in the presence of Mg2+. Human ovarian carcinoma cells A2780 were treated with nitrogen mustard (HN2), fixed in methanol, and stained with monoclonal antibody (MOAB) F7-26 generated against HN2-treated DNA. Binding of MOAB was measured by flow cytometry with indirect immunofluorescence. The maximal difference in fluorescence between untreated and HN2-treated cells was observed after heating at 100 degrees C for 5 min in PBS containing 1.25 mM MgCl2. Higher concentrations of MgCl2 inhibited MOAB binding to HN2-treated cells and heating at lower concentrations induced binding to control cells. Intensive binding of MOAB to control and drug-treated cells was observed after heating in Tris buffer supplemented with MgCl2. Thus, the presence of phosphates and MgCl2 during heating was necessary for the detection of HN2-induced changes in DNA stability. Fluorescence of HN2-treated cells decreased to background levels after treatment with single-strand-specific S1 nuclease. MOAB F7-26 interacted with single-stranded regions in DNA and did not bind to dsDNA or other cellular antigens. Specific reactivity of MOAB F7-26 with deoxycytidine was established by avidin-biotin ELISA. Single-stranded conformation was necessary for the binding of MOAB to deoxycytidine on the DNA molecule. It is suggested that alkylation of guanines decreased the stability of the DNA molecule and increased the access of MOAB F7-26 to deoxycytidines on the opposite DNA strand.
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PMID:Decreased stability of DNA in cells treated with alkylating agents. 225 76

Monoclonal antibodies generated against human milk fat globule membrane antigens were used in antibody-guided tumour imaging and palliative therapy in a case of wide-spread ovarian carcinoma. Antibody III H 2, which previously has been shown to react with 100% of ovarian cystadenocarcinomas showed a strong reactivity with tissue sections obtained from the primary and metastatic tumours of the patient. Immunoglobulins were purified from mouse ascitic fluid containing III H 2 and labelled with 123I or 131I with the iodogen method. 80 MBq (2 mCi) of 123I-labelled antibody was given intraperitoneally in 500 ml of PBS and the uptake of radiolabel was followed daily with emission tomography. Radiolabel was mainly located in the peritoneal cavity; only a very low activity was seen in the thyroid gland and urinary bladder. A therapeutic dose consisting of 600 MBq (15 mCi) of 131I-labelled antibody was followed nine days later and the localization of the antibody was followed.
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PMID:The use of radiolabelled monoclonal antibodies to human milk fat globule membrane antigens in antibody-guided tumour imaging, and administration of therapeutic dose of labelled antibody in wide-spread ovarian carcinoma. A preliminary report. 386 32

The intracellular uptake and localization of a fluorescently labeled Pluronic P-105 in HL-60 leukemia cells and in A2780 drug-sensitive and A2780/ADR MDR ovarian carcinoma cells were characterized by flow cytometry and fluorescence microscopy. Pluronic P-105 molecules were labeled with a pH-sensitive fluorescent label, 5-(and 6-)carboxy-2'7'-dichlorofluorescein. The fluorescence intensity of labeled Pluronic was about twofold higher at pH 7.4 than at pH 5.5. At Pluronic concentrations exceeding the critical micelle concentration (cmc), flow cytometry histograms manifested bimodal distribution of cell fluorescence for all types of cells. Cell population characterized by higher fluorescence intensity presumably resulted from Pluronic transfer from the acidic environment of cytoplasmic vesicles (endosomes or lysosomes) into the neutral environment of the cytoplasm and cell nuclei, which suggested the permeabilization of the membranes of acidic vesicle by Pluronic molecules. For the MDR cells, the bimodal distribution of cell fluorescence was already observed at very low Pluronic concentrations in the incubation medium (i.e., below the cmc). The data suggest that the membranes of acidic vesicles of MDR cells are more susceptible to the action of polymeric surfactants than those of drug-sensitive cells. Permeabilization of acidic vesicles had a dramatic effect on the intracellular trafficking of drugs: when delivered in PBS, the anthracyclin drug ruboxyl (Rb) sequestered in cytoplasmic vesicles and was excluded from cell nuclei; however, when delivered in Pluronic micelles, drug accumulated in cell nuclei. Drug uptake from/with Pluronic micelles was substantially enhanced by ultrasound. These findings suggest that the nuclear accumulation of drugs internalized via fluid-phase endocytosis can be enhanced by the application of Pluronic micelles and can be further augmented by ultrasonic irradiation.
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PMID:Intracellular uptake and trafficking of Pluronic micelles in drug-sensitive and MDR cells: effect on the intracellular drug localization. 1178 5

The effect of high-frequency ultrasound on doxorubicin (DOX) release from Pluronic micelles and intracellular DOX uptake was studied for promyelocytic leukemia HL-60 cells, ovarian carcinoma drug-sensitive and multidrug-resistant (MDR) cells (A2780 and A2780/ADR, respectively), and breast cancer MCF-7 cells. Cavitation events initiated by high-frequency ultrasound were recorded by radical trapping. The onset of transient cavitation and DOX release from micelles were observed at much higher power densities than at low-frequency ultrasound (20-100 kHz). Even a short (15-30 s) exposure to high-frequency ultrasound significantly enhanced the intracellular DOX uptake from PBS, RPMI 1640, and Pluronic micelles. The mechanisms of the observed effects are discussed.
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PMID:Drug delivery in pluronic micelles: effect of high-frequency ultrasound on drug release from micelles and intracellular uptake. 1239 66

The results of a comprehensive in vivo study of a novel tumor-targeting modality are reported. The technique utilized in this study is based on the encapsulation of the chemotherapeutic agent within polymeric micelles in combination with a local ultrasonic irradiation of the tumor. A doxorubicin (DOX) biodistribution, a yield of the internal tumors and a growth rate of the subcutaneous (s.c.) tumors was compared for molecularly dissolved and micellar-encapsulated DOX. This was done with and without tumor sonication, using an ovarian carcinoma tumor model in nu/nu mice. Pure and mixed Pluronic P-105, PEG2000-diacylphospholipid, and poly(ethylene glycol)-co-poly(beta-benzyl-L-aspartate) micelles were used as drug carriers. DOX intracellular uptake was characterized by flow cytometry. A local ultrasonic irradiation of the tumor resulted in a substantially increased drug accumulation in the tumor cells. The effect of the ultrasound was dependent on the time between ultrasound application and drug injection. Ultrasound did not enhance micelle extravasation; the ultrasonic enhancement of drug internalization by the tumor cells required a preliminary passive drug accumulation in the tumor interstitium. Due to the ultrasound-enhanced drug intracellular uptake and cell killing, the yield of intraperitoneal (i.p.) ovarian carcinoma tumors decreased from 70% for DOX dissolved in PBS (positive control) to 36% for the same concentration of DOX encapsulated in Pluronic micelles combined with a 30-s sonication of the abdominal region of a mouse (3 mg/kg DOX, i.p. injection 1 day after inoculation, n>or=10). For s.c. tumors, micellar delivery combined with localized ultrasonic tumor irradiation resulted in a substantial decrease of the tumor growth rates compared to a positive control (3 mg/kg DOX, i.v. injections, n=7, p<0.05). Possible mechanisms of the ultrasound bioeffects on in vivo drug targeting are discussed.
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PMID:Controlled and targeted tumor chemotherapy by micellar-encapsulated drug and ultrasound. 1565 46

All-trans-retinoic acid (ATRA) is now included in many antitumor therapeutic schemes for the treatment of acute promyelocytic leukaemia, Kaposi's sarcoma, head and neck squamous cell carcinoma, ovarian carcinoma, bladder cancer and neuroblastoma. Unfortunately its poor aqueous solubility hampers its parenteral formulation. To date, there is no parenteral formulation of ATRA commercially available and oral administration of ATRA is associated with progressively diminishing ATRA levels in plasma, which is related to induction of retinoic acid-binding protein and increased drug catabolism by cytochrome P-450-mediated reaction. An ATRA formulation, obtained by complexation of the drug into polymeric micelles, might be suitable for parenteral administration overcoming these unwanted effects. To this purpose we prepared an amphiphilic polymer by polyvinylalcohol (PVA) substitution with oleyl amine at 1.5% substitution degree (mol substituent per 100 mol hydroxyvinylmonomer) and evaluated its functional properties with regard to ATRA complexation. The substituted polymer displayed ability to interact with ATRA both in aqueous solution and in the solid state following spray-drying of drug-polymer hydro-alcoholic solutions. The spray-dried complexes rapidly dissolved in water providing high levels of ATRA solubilization as a function of the drug-polymer weight ratio. The complexes characterized by 1:5 drug-polymer weight ratio provided higher levels of ATRA solubilization than 1:3 and 1:10 drug-polymer weight ratios respectively. Pre-formed polymeric micelles in water equilibrated in the presence of excess solid ATRA provided the lowest levels of solubilization. The drug release from the complexes was very slow in PBS, indicating their suitability in antitumor drug targeting where a fundamental requirement is stability towards drug release for at least 24 h, corresponding to the average circulation time period of macromolecular carriers. The cytotoxicity studies against neuroblastoma cell lines outlined increased cytotoxicity of complexed ATRA with respect to free ATRA, likely due to the increased bioavailability of the hydrophobic drug from the complex. We conclude that ATRA entrapped into self-assembling polymer micelles may be a useful parenteral ATRA formulation overcoming the unwanted pharmacological mechanism that lead to acquired retinoid resistance.
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PMID:Modified polyvinylalcohol for encapsulation of all-trans-retinoic acid in polymeric micelles. 1576 20

The adenoviral mutant dl922-947 has potent activity in a variety of tumors. We investigated the efficacy of dl922-947 in ovarian carcinoma; compared its activity to wild-type adenovirus, dl309, and dl1520; and investigated the use of icodextrin to enhance activity in vivo. We also assessed the utility of luciferase bioluminescence imaging to quantify the response of human ovarian carcinoma xenografts to dl922-947. Ovarian carcinoma cell lines were transfected in vitro with dl922-947, adenovirus 5 wild-type (Ad5 WT), dl309, and dl1520 and monitored for S-phase induction, viral protein expression, replication, and overall survival. In vivo, the efficacy of dl922-947 when delivered in PBS or icodextrin to female nude mice bearing IGROV1 xenografts was determined. In vitro, dl922-947 induced lysis with greater efficacy than Ad5 WT, dl309, or dl1520 in all ovarian carcinoma cell lines tested, which was associated with earlier expression of viral proteins and S-phase induction. The lytic effect in immortalized ovarian surface epithelial cells confirmed that cellular retinoblastoma pathway status is a strong determinant of dl922-947 activity. In vivo, i.p. delivery of dl922-947 (5 x 10(9) particles daily x 5) increased median survival from 20 to 96 days (P < 0.0001) and delivery in icodextrin-enhanced survival further. However, delayed hepatic toxicity was evident in some dl922-947-treated mice, which was not dependent upon viral replication within tumor cells or the liver. dl922-947 has potency in ovarian carcinoma and i.p. delivery in icodextrin may enhance this activity. Immunocompetent models of ovarian carcinoma are required for further evaluation of hepatotoxicity.
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PMID:Activity of the adenoviral E1A deletion mutant dl922-947 in ovarian cancer: comparison with E1A wild-type viruses, bioluminescence monitoring, and intraperitoneal delivery in icodextrin. 1642 34

Epithelial ovarian cancer (EOC) is the fifth most common cancer in women and is characterized by a low 5-year survival rate. One strategy that can potentially improve the overall survival rate in ovarian cancer is the use of antitumor agents such as ABT-510. ABT-510 is a small mimetic peptide of the naturally occurring antiangiogenic compound thrombospondin-1 and has been shown to significantly reduce tumor growth and burden in preclinical mouse models and in naturally occurring tumors in dogs. This is the first evaluation of ABT-510 in a preclinical model of human EOC. Tumorigenic mouse surface epithelial cells were injected into the bursa of C57BL/6 mice that were treated with either 100 mg/kg ABT-510 or an equivalent amount of PBS. ABT-510 caused a significant reduction in tumor size, ascites fluid volume, and secondary lesion dissemination when compared with PBS controls. Analysis of the vasculature of ABT-510-treated mice revealed vascular remodeling with smaller diameter vessels and lower overall area, increased number of mature vessels, and decreased tissue hypoxia. Tumors of ABT-510-treated mice had a significantly higher proportion of apoptotic tumor cells compared with the PBS-treated controls. Immunoblot analysis of cell lysates revealed a reduction in vascular endothelial growth factor, vascular endothelial growth factor receptor-2, and proliferating cell nuclear antigen protein expression as well as expression of members of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase survival pathways. In vitro, ABT-510 induced tumor cell apoptosis in mouse and human ovarian cancer cells. This study shows ABT-510 as a promising candidate for inhibiting tumor growth and ascites formation in human EOC.
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PMID:ABT-510 induces tumor cell apoptosis and inhibits ovarian tumor growth in an orthotopic, syngeneic model of epithelial ovarian cancer. 1913 14

Human PNAS-4 (hPNAS-4), as a pro-apoptotic gene, can inhibit tumor growth when overexpressed in some malignant cells. Poly (lactic-co-glycolic acid) (PLGA) was used as a gene transfer vector due to the advantage of sustained release, nontoxicity and biodegradability. In this study, we aimed to investigate the effect of PLGA nanoparticles encapsulating hPNAS-4 combined with cisplatin (DDP) on ovarian carcinoma. Expression of hPNAS-4 was determined by RT-PCR. Mice bearing intraperitoneal ovarian carcinomas were treated with PBS, pVAX-PLGA nanoparticles (P-P), pVAX-hPNAS-4-PLGA nanoparticles (PhP-P), DDP and PhP-P plus DDP, respectively. Intraperitoneal tumors were weighed to assess the antitumor efficacy. The percentage of proliferative cells and apoptotic cells was evaluated by Ki-67 staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling. The anti-angiogenic effects were detected by CD31 staining and the alginate-encapsulate assay. Overexpression of hPNAS-4 was detected by RT-PCR in the PhP-P and PhP-P plus DDP groups. PhP-P exerted significant antitumor activity through induction of apoptosis, inhibition of cell proliferation and suppression of angiogenesis, compared with treatment with P-P or PBS alone. The combination of PhP-P with DDP showed enhanced antitumor activity compared with therapy of PhP-P or DDP alone. PLGA encapsulating hPNAS-4 combined with DDP may have promising applications in the therapy of ovarian cancer.
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PMID:Antitumor effects of PLGA nanoparticles encapsulating the human PNAS-4 gene combined with cisplatin in ovarian cancer. 2166 29

A RGD peptide mimetic was conjugated to four camptothecins, with the purpose to improve their therapeutic index. The conjugate derivatives were evaluated against two tumor cell lines, one overexpressing integrins (human ovarian carcinoma, A2780) and a second one with a low integrin expression (human prostate cancer, PC3). The in vitro screening was completed with the adhesion behavior to vitronectin. Compound 8 (ST7456CL1) was selected for the in vivo investigation after stability tests over 24h, in PBS solution and in rat plasma, and compared to irinotecan. The former showed a prolonged half-life.
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PMID:Camptothecins in tumor homing via an RGD sequence mimetic. 2295 46


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