Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hematopoietic stem cells (HSC) require extensive cytokine-mediated stimulation and proliferation for efficient transduction by oncoretroviral vectors. Since lentiviral vectors can transduce nondividing cells, the need for cytokine stimulation has been questioned. We studied HIV-based lentiviral transduction of human early hematopoietic progenitors from umbilical cord blood in the presence or absence of IL-3, IL-6, stem cell factor (SCF), and Flt-3L (36SF) or SCF alone and characterized the effects of these conditions on the stem cell phenotype. Gene transfer was significantly higher in the presence of 36SF in mass culture cells, CFC, LTCIC, and NOD/SCID repopulating cells (SRC). Transduction of primitive progenitor/stem cells was poor without cytokines, with only 12% LTCIC and 23% SRC transduced, compared to 59% in LTCIC and 81% in SRC with 36SF. SCF alone matched transduction rates of multiple cytokines with 70% in CFC. Cytokines prevented apoptosis, expanded CD34(+) cell number, and maintained CFC and LTCIC frequencies. Cytokine stimulation increased transduction of nondividing Ara-C-resistant and aphidicolin-inhibited cells similar to dividing cells. These data suggest that cytokines enhance lentiviral transduction of HSC, without requiring cell division, and maintain the stem cell phenotype. SCF stimulation alone was sufficient for high level transduction.
Mol Ther 2003 Mar
PMID:Cytokines, including stem cell factor alone, enhance lentiviral transduction in nondividing human LTCIC and NOD/SCID repopulating cells. 1266 28

We constructed a prokaryotic vector expressing a truncated VP22-EGFP gene and purified this fusion protein from Escherichia coli cultures using nickel resin. Application of purified VP22-EGFP protein to human pancreatic carcinoma cells showed a highly efficient time-dependent and dose-dependent uptake and resulted in green fluorescence predominantly located in the nuclei of treated cells. Purified VP22-EGFP efficiently translocated into deeper layers of pancreatic tumor cell spheroids. Homogeneous uptake into the whole tumor was observed after peritumoral injection in human pancreatic tumors in SCID mice. We conclude that the direct application of purified VP22 fusion proteins offers a new, peptide-mediated and potentially systemic therapy for pancreatic cancer. This opens the possibility of achieving specific antitumor effects induced by fused apoptosis-enhancing proteins.
J Mol Med (Berl) 2003 Mar
PMID:Efficient dose-dependent and time-dependent protein transduction of pancreatic carcinoma cells in vitro and in vivo using purified VP22-EGFP fusion protein. 1268 29

P-glycoprotein (Pgp) is an ABC (ATP binding cassette) transporter that is often overexpressed in tumours, contributing significantly to their multidrug resistance. In this study, we explored whether the radiotracers used in tumour diagnostics can be used for in vivo visualisation of Pgp-related multidrug resistance. We also examined the effects of different Pgp modulators on the accumulation of these radioligands in tumours with or without Pgp expression. In a SCID BC-17 mouse model, cells of the drug-sensitive KB-3-1 (MDR(-)) and the KB-V1 Pgp-expressing (MDR(+)) human epidermoid carcinoma cell lines were inoculated to yield tumours in opposite flanks. For in vivo scintigraphic (biodistribution) and positron emission tomography (PET) examinations, the mice were injected with technetium-99m hexakis-2-methoxybutylisonitrile ((99m)Tc-MIBI), carbon-11 labelled methionine and fluorine-18 fluoro-2-deoxy- d-glucose ((18)FDG). For validation, in vitro cell studies with (99m)Tc-MIBI,( 99m)Tc-tetrofosmin, [(11)C]methionine and (18)FDG were carried out using a gamma counter. The expression and function of the MDR product were proved by immunohistochemistry and spectrofluorimetry. (99m)Tc-MIBI uptake was significantly lower in KB-V1 cells as compared with KB-3-1-derived tumours in vivo (Pgp(+)/Pgp(-) =0.61+/-0.13; P<0.01) and cells in vitro (Pgp(+)/Pgp(-) =0.08+/-0.01; P<0.001).()Cyclosporin A reversed (99m)Tc-MIBI uptake in the Pgp+ cells, while verapamil failed to modify it. (18)FDG uptake was significantly higher in KB-V1 tumours (Pgp(+)/Pgp(-) =1.36+/-0.05; P<0.01) and cells (Pgp(+)/Pgp(- )=1.52+/-0.12; P<0.001). Whereas cyclosporin A eliminated the difference between FDG uptake in MDR(+) and MDR(-) cell lines, verapamil significantly increased it. When the animals were treated with verapamil, the ratio of (99m)Tc-MIBI uptake in the MDR(+) tumours to that in the MDR(-) tumours decreased to 0.38+/-0.05 ( P<0.01), while the ratio of (18)FDG uptake increased to 2.1+/-0.3 ( P<0.001). There were no significant differences in the [(11)C]methionine uptake in the MDR(+) and MDR(-) tumours and cell lines, nor was [(11)C]methionine accumulation modified by cyclosporin A. Parallel administration of (18)FDG and (99m)Tc-MIBI combined with verapamil treatment seems to be a good candidate as a non-invasive marker for the diagnosis of MDR-related Pgp expression in tumours.
Eur J Nucl Med Mol Imaging 2003 Aug
PMID:In vivo and in vitro multitracer analyses of P-glycoprotein expression-related multidrug resistance. 1283 Mar 25

The phenomenon of RNA interference mediated by small interfering RNAs (siRNAs) is a potent gene-silencing mechanism. A number of recent studies demonstrated inhibition of HIV-1 replication in cultured cells using this approach. To make further progress and harness this technology for HIV-1 gene therapy in a stem cell setting, in vivo studies using primary hematopoietic cells are needed. Using an HIV-based lentiviral vector we introduced an anti-Rev siRNA construct into CD34(+) hematopoietic progenitor cells. The siRNA-transduced progenitor cells were allowed to mature into macrophages in vitro and T cells in vivo in SCID-hu mouse thy/liv grafts. Phenotypically normal T cells and macrophages displaying characteristic surface markers were obtained. In vitro HIV-1 challenge of the siRNA-expressing macrophages and T cells with macrophage-tropic and T-cell-tropic HIV-1, respectively, showed marked viral resistance. These experiments demonstrate the utility of siRNAs delivered into hematopoietic stem cells via lentiviral vectors for future in vivo applications.
Mol Ther 2003 Jul
PMID:Inhibition of HIV-1 by lentiviral vector-transduced siRNAs in T lymphocytes differentiated in SCID-hu mice and CD34+ progenitor cell-derived macrophages. 1284 29

Diamond Blackfan Anemia (DBA) is a congenital disorder characterized by decreased red blood cell production and developmental abnormalities. We herein show that DBA progenitors produced lower numbers of phenotypically normal erythroid colonies in vitro, whereas nonerythroid colonies were normally abundant and developed. To determine whether DBA stem cells are capable of producing early erythroid, monocyto-granulocytic, and lymphoid progenitors in vivo we used a mouse xenotransplantation model. We demonstrate that DBA stem cells poorly repopulated erythroid progeny in NOD/SCID mice, whereas the monocyto-granulocytic and lymphoid progenies were repopulated normally. Therefore, we conclude that disordered DBA erythropoiesis may be a result of defective erythroid-lineage commitment and maintenance of early erythroid progenitors.
Blood Cells Mol Dis
PMID:Diamond blackfan anemia stem cells fail to repopulate erythropoiesis in NOD/SCID mice. 1285 Apr 91

The purpose of this study was to evaluate the extent to which the expression of p53, c-myc, bcl-2, ras genes and chromosomes, along with activity of hTERT, impacts on the malignant transformation of immortalized esophageal epithelial cells. The SHEE cell line was established from an embryonic esophageal epithelial cell induced by transduction of E6E7 genes of human papillomavirus type 18 (HPV18E6E7). In cells of the 85th passage (SHEE85), the malignant transformation of SHEE was confirmed by morphology, cell proliferative index and tumor formation in SCID mice. C-myc, p53, bcl-2 and ras genes were assayed by the multi-PCR method with house-keeping gene GAPDH as control. The modal number of chromosomes was analyzed and its expression of subunit of telomerase, hTERT, was assessed by RT-PCR. Expression of HPV18E6E7 was assayed by Western blotting. The results showed that cells of SHEE85 were atypical and exhibited proliferative status with a proliferation index of 45.70%. Tumors formed in SCID mice with invasion of adjacent tissue. The karyotype belonged to hypotriploid and displayed expression of hTERT. C-myc, k-ras, bcl-2 and p53 (expression of phosphoprotein) were positive in SHEE85. Expression of HPV18E6E7 was positive. Taken together, SHEE85 cells were in fully malignant transformation and their molecular mechanism involved the expression of cellular genes, such as p53, bcl-2, c-myc and ras, and aberrance of chromosomes. It is probable that all of these changes were related with HPV18E6E7.
Int J Mol Med 2003 Aug
PMID:Cytogenetic and molecular genetic changes in malignant transformation of immortalized esophageal epithelial cells. 1285 21

The present study was undertaken to analyze the regulatory T cells generated in response to class I derived self-I-A beta(g7) (54-76) peptide. It was observed T cells from young unprimed type 1 diabetes (T1D) prone NOD mice did not respond to self-I-A beta(g7) (54-76) peptide although T cells from primed young NOD mice showed a strong response. T cells from young unprimed BALB/c mice responded to self-I-A beta(d) (62-78) peptide. However, a breakdown of tolerance to these peptides was observed with age in both the strains. Culture supernatant from I-A beta(g7) (54-76) peptide-primed cells secreted large amounts of TGF-beta and inhibited T cell responses in allogeneic-MLR. Further, I-A beta(g7) (54-76) peptide specific T cell lines from young (I-A.Y) and diabetic (I-A.D) NOD mice were established. I-A.Y secreted IL-4, TGF-beta and IL-10 while I-A.D T cell line secreted IL-10 and IFN-gamma. We found that I-A.D T cell line induced diabetes when transferred in NOD/SCID mice but I-A.Y T cell line did not induce disease. These results show that immunization of NOD mice with I-A beta(g7) (54-76) peptide at a younger age induces a regulatory T cell response suggesting that correcting the defects in immunoregulatory mechanisms using self-MHC peptides may be one of the approaches to prevent autoimmune diseases like T1D.
Cell Mol Biol (Noisy-le-grand) 2003 Mar
PMID:Regulation of type 1 diabetes by a self-MHC class II peptide: role of transforming growth factor beta (TGF-beta). 1288 99

The HSV-1 1716 mutant virus and similar oncolytic herpesviruses deficient in the gamma 34.5 neurovirulence gene are able to reduce the growth of tumors in mice. Here we demonstrate that HSV-1 1716 therapy moderately reduced the growth of tumors of the highly malignant, spontaneously metastasizing 4T1 mouse mammary carcinoma model. This moderate effect on 4T1 tumor growth was likely due to poor replication kinetics of HSV-1 1716 in 4T1 cells. Interestingly, HSV-1 therapy of the primary tumor increased the survival time of mice. Coincident with this increase was a reduction in metastases as determined by quantification of the number of metastatic cells in the lungs. HSV-1 therapy of the primary tumor was also able to reduce the establishment of a second challenge of 4T1 tumors. Moreover, infiltrates of both CD4(+) and CD8(+) T cells were detected in HSV-1 1716-treated tumors. An important role for the T cell infiltrates was confirmed when HSV-1 therapy did not reduce the growth of 4T1 tumors in SCID mice. Collectively, these results demonstrate that an HSV-dependent anti-tumor immune response is required for the reduction in primary 4T1 tumor growth and for the reduction in the establishment of metastases in this tumor model.
Mol Ther 2003 Oct
PMID:HSV-1 therapy of primary tumors reduces the number of metastases in an immune-competent model of metastatic breast cancer. 1452 26

Recently, RD114 (feline endogenous retrovirus envelope protein)-pseudotyped retroviral particles have been shown to transduce human NOD/SCID repopulating cells efficiently. In this study, we compared directly transduction of repopulating cells with RD114-pseudotyped vector to that with standard amphotropic vector in the rhesus macaque model. G-CSF/SCF-mobilized CD34(+) rhesus peripheral blood cells were cultured in the presence of SCF, Flt-3 ligand, and MGDF on Retronectin-coated flasks. To assess directly the ability of the two pseudotypes to transduce primitive cells, both vectors were added simultaneously to the target cells every 24 h, for a total of four exposures in 96 h. The cells were reinfused after the animals received 1000 cGy total body irradiation. At the end of transduction, gene marking efficiency of CFU was higher with amphotropic LNL6 vector (mean 88.4%) vs RD114-G1Na vector (mean 18.5%). After long-term engraftment in three animals, total neo gene marking levels were 4-5% in PBMNCs and 1.5-4% in granulocytes. The RD114-G1Na marking levels were consistently higher in granulocytes than in mononuclear cells, while amphotropic LNL6 marking levels were higher in PBMNCs than in granulocytes. The differential gene marking patterns suggest that RD114 and amphotropic vectors may target distinct progenitor or stem cell populations. There was no clear advantage for RD114-pseudotyped vectors in this predictive preclinical model in terms of overall long-term marking levels; however, optimization of transduction conditions by increasing m.o.i. or inducing the receptor could potentially improve results with this novel vector system.
Mol Ther 2003 Oct
PMID:Direct comparison of RD114-pseudotyped versus amphotropic-pseudotyped retroviral vectors for transduction of rhesus macaque long-term repopulating cells. 1452 34

Human papillomavirus type 16 (HPV16), a causative agent of cervical cancers, encodes the E6 and E7 oncogenes, whose simultaneous expression is pivotal for malignant transformation and maintenance of malignant phenotypes. In the hope of developing a gene-specific therapy for HPV-related cancer, we examined the effects of E6 short-interfering RNA (siRNA) on the expression of these oncogenes and on the cell growth of HPV16-related cervical cancer cells. Using SiHa cervical cancer cells, we demonstrated that E6 siRNA decreased the levels of mRNA encoding E6 as well as that encoding E7 protein and also induced nuclear accumulation of p53, the most important target of E6. E6 siRNA suppressed monolayer and anchorage-independent growth of SiHa cells, which was associated with p21(CIP1/WAF1) induction and hypophosphorylation of retinoblastoma protein. Further, SiHa cells treated with E6 siRNA formed tumors in NOD/SCID mice that were significantly smaller than in those treated with control siRNA. Our results show HPV E6 siRNA as a candidate for gene-specific therapy for HPV-related cervical cancer.
Mol Ther 2003 Nov
PMID:In vitro and in vivo growth suppression of human papillomavirus 16-positive cervical cancer cells by E6 siRNA. 1459 9


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