Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.7.49 (reverse transcriptase)
31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) has been investigated for biomedical applications due to its many biologically favorable properties. However, to explore its application in bone tissue engineering, the poorly bioactive surface property of PHBV must be improved. To engineer PHBV to achieve a biologically active surface, in this study each porous PHBV matrix was prepared by solute leaching of salt/PHBV cast film and was treated with ozone followed by dip coating with type I collagen. The biological responses of osteoblast-like UMR-106 cells after being grown on the engineered PHBV matrix were evaluated. Confocal microscopy and the MTT assay were used to map and quantify the viable cell proliferation on the PHBV matrix, respectively. The cells were cultivated in osteogenic media containing beta-glycerophosphate and later stained with alizarin red to visualize mineralization of the matrix. RNA was extracted from the UMR-106 cells, and reverse transcriptase-polymerase chain reaction (RT-PCR) was applied to detect expression of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) (a house keeping gene) and bone sialoprotein (BSP) (marker of the osteoblastic phenotype). The results showed that the UMR-106 cells after cultivation on the engineered PHBV matrix retained the osteoblastic phenotype characteristics, indicating that the porous PHBV matrix after ozone treatment and collagen dip coatings are a promising scaffold for bone tissue engineering applications.
...
PMID:Evaluation of the biological responses of osteoblast-like UMR-106 cells to the engineered porous PHBV matrix. 1718 85

The purpose of current experiment is the generation of insulin-producing human mesenchymal stem cells as therapeutic source for the cure of type 1 diabetes. Type 1 diabetes is generally caused by insulin deficiency accompanied by the destruction of islet beta-cells. In various trials for the treatment of type 1 diabetes, cell-based gene therapy using stem cells is considered as one of the most useful candidate for the treatment. In this experiment, human mesenchymal stem cells were transduced with AAV which is containing furin-cleavable human preproinsulin gene to generate insulin-producing cells as surrogate beta-cells for the type 1 diabetes therapy. In the rAAV production procedure, rAAV was generated by transfection of AD293 cells. Human mesenchymal stems cells were transduced using rAAV with a various multiplicity of infection. Transduction of recombinant AAV was also tested using beta-galactosidse expression. Cell viability was determined by using MTT assay to evaluate the toxicity of the transduction procedure. Expression and production of Insulin were tested using reverse transcriptase-polymerase chain reaction and immunocytochemistry. Secretion of human insulin and C-peptide from the cells was assayed using enzyme-linked immunosorbent assay. Production of insulin and C-peptide from the test group represented a higher increase compared to the control group. In this study, we examined generation of insulin-producing cells from mesenchymal stem cells by genetic engineering for diabetes therapy. This work might be valuable to the field of tissue engineering for diabetes treatment.
...
PMID:Generation of insulin-producing human mesenchymal stem cells using recombinant adeno-associated virus. 1732 53

A human cervical explant culture was utilized for the preclinical assessment of anti-human immunodeficiency virus type 1 (HIV-1) activity and tissue toxicity of formulated, candidate topical microbicides. Products tested included cellulose acetate 1,2-benzene dicarboxylate (CAP), a carrageenan-based product (PC-515), a naphthalene sulfonate polymer (PRO 2000), a lysine dendrimer (SPL7013), a nonnucleoside reverse transcriptase inhibitor (UC781), and an antimicrobial peptide (D2A21), along with their placebos. Cervical explants were cultured overnight with HIV-1 with or without product, washed, and monitored for signs of HIV-1 infection. HIV-1 infection was determined by p24gag levels in the basolateral medium and by immunohistochemical analysis of the explant. Product toxicity was measured by the MTT [1-(4,5-dimethylthiazol-2-yl)-3,5-diphenylformazan] assay and histology. CAP, PRO 2000, SPL7013, and UC781 consistently prevented HIV-1 infection in all explants tested. PC-515 and D2A21 prevented HIV-1 infection in 50% or fewer of the explants tested. Placebos did not prevent infection in any of the explants tested. With the exception of PRO 2000 (4%), the MTT assay and histological analysis of the other products and placebos showed minimal toxicity to the epithelium and submucosa. Collectively, these data suggest that this culture system can be used for evaluating the safety and efficacy of topical microbicides designed for vaginal use.
...
PMID:Preclinical testing of candidate topical microbicides for anti-human immunodeficiency virus type 1 activity and tissue toxicity in a human cervical explant culture. 1735 37

Most apoptosis-related genes regulate cellular fate as a response to anticancer drugs. Modulations at the mRNA levels of such genes often correlate with the sensitivity of various types of cancer cells to chemotherapeutic reagents. The drugs cisplatin, carboplatin, and doxorubicin exhibit anticancer activity, the mechanism of which is not yet completely clarified, although they are known to modulate the expression of several genes including apoptosis-related genes, such as members of the BCL2 (Bcl-2) family. In order to define the significance of the expression patterns of such genes as a response to anticancer drug cytotoxic activity, we studied the possible alterations in the mRNA expression levels of various apoptosis-related genes, including the new member, BCL2L12, after cell treatment with distinct anticancer drugs (cisplatin, carboplatin, and doxorubicin), in the breast cancer cell line, MCF-7. The kinetics of cell toxicity was evaluated by the MTT method, whereas the expression levels of distinct apoptosis-related genes were analyzed by reverse transcriptase polymerase chain reaction (RT-PCR), using gene-specific primers. The percentage of nonviable cells was upregulated with increasing concentrations and cell exposure time to the different anticancer drugs. Distinct modulations of apoptosis-related genes, at the mRNA level, were also observed. However, further work is required in order to ascertain whether the mRNA expression profile of such genes may provide evidence for their contribution to more specific and sensitive prediction of breast cancer response to treatment and therefore the rationale for individualized, more appropriate, and successful treatment.
...
PMID:Breast cancer cells response to the antineoplastic agents cisplatin, carboplatin, and doxorubicin at the mRNA expression levels of distinct apoptosis-related genes, including the new member, BCL2L12. 1740 15

To investigate the mechanism of the resistance to cisplatin (CDDP), we established the CDDP-resistant cell line, KB-R, from CDDP-sensitive oral carcinoma cell line, KB. The 3-(3, 4-dimethyl-thiazol-2-yl) 2, 5-diphenyltetrazolium bromide (MTT) assay indicated that KB-R is 5.5-fold more resistant to CDDP than KB. Microarray analysis indicated that the expression levels of 1,718 genes were elevated at least five-fold or more in KB-R, compared with KB. The expression status of ATP binding cassette (ABC) transporter genes, which belong to multi-drug resistance genes, was confirmed by semiquantitative reverse transcriptase-polymerase chain reaction and real-time PCR. MRP1 and MRP2 were up-regulated, whereas MDR1 was down-regulated. Pathway and ontology analysis using the Ingenuity Pathway Analysis tool indicated three highly significant genetic networks including 105 of the 1,718 overexpressed genes and one network including 35 'cell-to-cell signaling and interaction' related genes. Our results suggested that these cell lines, KB and KB-R, may be useful for searching the candidate genes responsible for CDDP-resistance and for further study to understand the mechanism of CDDP-resistance.
...
PMID:Establishment and characterization of a cisplatin-resistant cell line, KB-R, derived from oral carcinoma cell line, KB. 1748 52

We have previously shown that transforming growth factor-beta1 (TGF-beta1) stimulates transdifferentiation of fibroblasts into smooth muscle alpha-actin (alpha-SMA) positive myofibroblasts. However, TGF-beta, as such, is unsuitable for effective population of a heart valve matrix, because it dose-dependently inhibits growth of fibroblasts. The aim of this study was to investigate combinations of other growth factors with TGF-beta to stimulate the proliferation of suitably differentiated cells and to enhance their invasion into aortic valve matrices. Human dermal mesenchymal cells (hDMC1.1) were treated with combinations of growth factors to stimulate these cells to trans-differentiate into myofibroblasts, to proliferate, and to invade. Growth factors were chosen after expression of their respective receptors was confirmed in hDMC1.1 using reverse transcriptase polymerase chain reaction. We combined TGF-beta with several growth factors such as insulin-like growth factor (IGF-1, IGF-2), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF-AA, PDGF-BB, and PDGFAB). Nuclear Ki67 staining, MTT assay, and cell counting revealed that only EGF and bFGF were capable of overcoming TGF-beta-induced growth inhibition. However, bFGF but not EGF inhibited TGF-beta-induced alpha-SMA expression, as evidenced by immuno-cytochemistry and Western blotting. A growth factor cocktail (TGF-beta, EGF, bFGF) has been established that maintains TGF-beta-induced trans-differentiation but overcomes TGF-beta-induced growth inhibition while stimulating fibroblast proliferation and invasion.
...
PMID:Growth factor modulation of fibroblast proliferation, differentiation, and invasion: implications for tissue valve engineering. 1751 40

The aim of this study was to explore the mechanism underlying the dual effect of androgen on prostate cancer cells and further explore its correlation with dopa decarboxylase (DDC), an androgen receptor (AR) coactivator and a traditional neuroendocrine differentiation (NED) marker. Cell proliferation and cycling after treatment with synthetic nonmetabolizable androgen R1881 was determined by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) method and flow cytometry. Differential gene expression was analyzed by cDNA microarrays. DDC expression during the dual effect of R1881 was further explored with microarray, quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, and enzyme activity assays. Proliferation of LNCaP cells was inhibited by 1 nM R1881 but stimulated by 0.1 nM R1881. Compared with the untreated cells, 320 (2.26%; 170 up-regulated, 150 down-regulated) and 4608 (32.65%; 2046 up-regulated, 2562 down-regulated) genes were found to be expressed differentially in the 1 nM and 0.1 nM R1881-treated cells, respectively. The results were partially confirmed by RT-PCR and Western blot. The DDC gene was down-regulated in the 1 nM R1881-treated cells and up-regulated in 0.1 nM R1881- and 30 nM hydroxyflutamide-treated cells. The enzymatic activity of DDC in the latter 2 groups was also strengthened. Meanwhile, the NED markers CgA and synaptophysin were not affected by these AR activators. R1881 had a dose-dependent biphasic effect on LNCaP cell proliferation. AR coactivator DDC was respectively down- and up-regulated in high and low concentrations of R1881. DDC up-regulation by exogenous AR activators is not accompanied by up-regulation of definitive NED markers.
...
PMID:Biphasic effect of androgens on prostate cancer cells and its correlation with androgen receptor coactivator dopa decarboxylase. 1758 45

This study was purposed to investigate the reversal effect of sodium selenite on multidrug resistance in adriamycin-resistant leukemic cell line K562/ADR and its mechanisms. The cytotoxicity and the reversal effect of sodium selenite on K562/ADR cells were assayed by MTT method; the apoptosis rate of K562 and K562/ADR cells were detected by flow cytometery, the mRNA expressions of mdr1 and bcl-2 were measured by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The results showed that 10 micromol/L sodium selenite significantly increased the cytotoxicity of adriamycin to K562/ADR cell and the reverse index (RI) was 2.31; the early apoptosis rate of K562 cells was elevated after treatment with 5 micromol/L Na(2)SeO(3) for 48 hours; and the medium-term and late apoptosis rate was elevated after treatment with both 5 and 10 micromol/L Na(2)SeO(3) for 48 and 72 hours. Both doses of 5 and 10 micromol/L Na(2)SeO(3) increased the early apoptosis rate of K562/ADR at 48 hours, and also increased the medium-term and late apoptosis rate after treating for 48 and 72 hours. The apoptosis rate was higher at dose of 10 micromol/L than that at 5 micromol/L, the apoptosis rate at 72 hours also was higher than that at 48 hours. The expressions of mdr1 mRNA and bcl-2 mRNA were decreased significantly by 10 micromol/L sodium selenite. It is concluded that sodium selenite can reverse the multidrug resistance in K562/ADR partially by down-regulating the expressions of mdr1 mRNA and bcl-2 mRNA, and increasing apoptosis rate of K562/ADR cells.
...
PMID:[Reversal effect of sodium selenite on multidrug resistance in K562/ADR cell line and its mechanisms]. 1770 98

Telomerase activity appears to be associated with cell immortalization and malignant progression. Understanding how telomerase activity is regulated in vivo is important not only for understanding the molecular biology of telomerase but also for the potential clinical application of anticancer drugs. This study evaluated telomerase activity and quantified the expression of human telomerase reverse transcriptase (hTERT) mRNA and human telomerase RNA (hTR) using a real-time reverse transcriptase-polymerase chain reaction (RT-PCR) method before and after the exposure of cisplatin and 5-fluorouracil (5-FU) in two head and neck squamous cell carcinoma (HNSCC) cell lines. Two human HNSCC cell lines (PNUH-12 and SNU-899) were studied. Cell cytotoxicity, the change of telomerase activity, and hTERT mRNA and hTR expression by 5-FU and cisplatin exposure were assessed by MTT assay, TRAP assay, and real-time RT-PCR, respectively. In two cell lines, after cisplatin exposure, the telomerase activity and hTERT mRNA expression decreased, but hTR expression in- creased according to the concentration of drug. However, in both cell lines, the telomerase activity and hTR did not show any significant change after 5-FU treatment, but the expression of hTERT mRNA decreased. These results suggest that there may be other important regulating mechanism except hTERT mRNA as the regulation factor of telomerase activity in HNSCC cell lines.
...
PMID:Change of the expression of human telomerase reverse transcriptase mRNA and human telomerase RNA after cisplatin and 5-fluorouracil exposure in head and neck squamous cell carcinoma cell lines. 1792 59

Heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AREG) are the members of EGF family that bind to common EGF receptor (EGFR) in the epidermis. However, the role of these two growth factors in epidermal hyperplasia of psoriasis has not been established. On the other hand, CD4+ T cells are responsible for the development of the psoriatic plaques. However, inflammatory cytokines, such as TNFalpha, IL-1beta and IFNgamma, inhibit the growth of human keratinocytes in vitro. The expression of HB-EGF, AREG and EGFR proteins in normal (n = 22) and psoriatic (n = 34) skin tissues was examined by immunohistochemistry. Then, the effects of HB-EGF and AREG on the growth of cultured adult normal human epidermal keratinocytes (NHEK-AD) with or without TH1 cytokines, such as TNFalpha, IL-1beta and IFNgamma, were examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, and the effects of these cytokines on the expression of EGFR mRNA in NHEK-AD were examined by real-time reverse transcriptase-polymerase chain reaction. The expression of HB-EGF and AREG in the epidermis was not specific to psoriatic plaques, but the distribution of positive cells throughout the epidermis was different between normal skins and psoriatic plaques. On the other hand, in the dermis and the papillary dermis, most of vascular endothelial cells and infiltrating mononuclear cells expressed both HB-EGF and AREG in normal skins and psoriatic plaques, and these positive cells were more frequent in psoriasis compared to normal skin. In the in vitro growth assay, HB-EGF, not AREG, stimulated the proliferation of NHEK-AD at the optimal concentration of 1 ng/ml. Furthermore, HB-EGF compensated the growth-suppressing effects of TNFalpha, IL-1beta and IFNgamma on NHEK-AD, and TNFalpha promoted the growth of NHEK-AD at the concentration of 2 and 20 U/ml in combination with HB-EGF and, in lesser extent, with AREG. However, TNFalpha did not affect the expression of EGFR mRNA in NHEK-AD. Growth factors and inflammatory cytokines produced in the dermis would be important for the epidermal proliferation in psoriatic plaques and TNFalpha may play a key role in cooperation with HB-EGF and AREG in the proliferation of epidermal keratinocytes at the psoriatic skin lesions.
...
PMID:The role of heparin-binding EGF-like growth factor and amphiregulin in the epidermal proliferation of psoriasis in cooperation with TNFalpha. 1796 Apr


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---