59 research outputs found
Adventitious shoot regeneration from in vitro stem explants of Phellodendron amurense
An efficient in vitro plant regeneration system from stem explants was established in Phellodendron amurense. Factors influencing shoot regeneration from stems including culture medium type, combinations of plant growth regulators and carbon source in the medium were investigated. Adventitious shoot regeneration was significantly influenced by the type of medium. Murashige and Skoog medium (MS) was the best for promoting shoot regeneration, followed by Gamborg medium (B5) and woody plant medium (WPM). The combination of 6-benzyladenine (BA) and naphthaleneacetic acid (NAA) produced better results for shoot regeneration. The optimum shoot regeneration frequency (74.5%) and number of shoots per explant (12.3) was achieved using MS medium supplemented with 29.7 M BA and 5.8 M NAA. High concentrations of BA and NAA in the medium inhibited shoot formation. Among the three sugars tested, 20 g dm-3 glucose was the optimum for shoot regeneration. Rooting of regenerated shoots was successful on 1/4-strength MS medium with the addition of 15.4 M IBA. Almost 100% plantlets survived acclimatization after transferred to soil.Key words: Phellodendron amurense, callus, shoot regeneration, stem explants
Anticancer activity of an extract from needles and twigs of Taxus cuspidata and its synergistic effect as a cocktail with 5-fluorouracil
<p>Abstract</p> <p>Background</p> <p>Botanical medicines are increasingly combined with chemotherapeutics as anticancer drug cocktails. This study aimed to assess the chemotherapeutic potential of an extract of <it>Taxus cuspidata </it>(<it>TC</it>) needles and twigs produced by artificial cuttage and its co-effects as a cocktail with 5-fluorouracil (5-FU).</p> <p>Methods</p> <p>Components of <it>TC </it>extract were identified by HPLC fingerprinting. Cytotoxicity analysis was performed by MTT assay or ATP assay. Apoptosis studies were analyzed by H & E, PI, TUNEL staining, as well as Annexin V/PI assay. Cell cycle analysis was performed by flow cytometry. 5-FU concentrations in rat plasma were determined by HPLC and the pharmacokinetic parameters were estimated using 3p87 software. Synergistic efficacy was subjected to median effect analysis with the mutually nonexclusive model using Calcusyn1 software. The significance of differences between values was estimated by using a one-way ANOVA.</p> <p>Results</p> <p><it>TC </it>extract reached inhibition rates of 70-90% in different human cancer cell lines (HL-60, BGC-823, KB, Bel-7402, and HeLa) but only 5-7% in normal mouse T/B lymphocytes, demonstrating the broad-spectrum anticancer activity and low toxicity to normal cells of <it>TC </it>extract <it>in vitro</it>. <it>TC </it>extract inhibited cancer cell growth by inducing apoptosis and G<sub>2</sub>/M cell cycle arrest. Most interestingly, <it>TC </it>extract and 5-FU, combined as a cocktail, synergistically inhibited the growth of cancer cells <it>in vitro</it>, with Combination Index values (CI) ranging from 0.90 to 0.26 at different effect levels from IC50 to IC90 in MCF-7 cells, CI ranging from 0.93 to 0.13 for IC40 to IC90 in PC-3M-1E8 cells, and CI < 1 in A549 cells. In addition, the cocktail had lower cytotoxicity in normal human cell (HEL) than 5-FU used alone. Furthermore, <it>TC </it>extract did not affect the pharmacokinetics of 5-FU in rats.</p> <p>Conclusions</p> <p>The combinational use of the <it>TC </it>extract with 5-FU displays strong cytotoxic synergy in cancer cells and low cytotoxicity in normal cells. These findings suggest that this cocktail may have a potential role in cancer treatment.</p
Loss of interferon regulatory factor 5 (IRF5) expression in human ductal carcinoma correlates with disease stage and contributes to metastasis
Pan-cancer analysis of whole genomes
Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
Animal Models of Human Cerebellar Ataxias: a Cornerstone for the Therapies of the Twenty-First Century
High yield production of salidroside in the suspension culture of Rhodiola sachalinensis
Salidroside has been identified as the most potent ingredient of the Chinese medicine herb, Rhodiola sachalinensis. Since the natural supply of this herb is rapidly decreasing, we established a compact callus aggregate (CCA) strain and culturing system for high yield salidroside production. Several callus strains induced from the explants originated from root, stem, leaf and cotyledon of R. sachalinensis were established and screened for rapid growth rate, high salidroside content and easy propagation in suspension culture condition. The CCA strain was established from a callus strain initiated from the cotyledon. The kinetics of dry weight accumulation and cellular salidroside content in various culture conditions for the strain was determined. For high salidroside production, the optimal inoculum amount was 10\% and the optimal concentration for 6-benzylaminopurine and indole-3-butyric acid added in the liquid medium was 5 and 2.5 mg l(-1), respectively. The acidic culture medium and a faster shaking speed favored the salidroside accumulation. The addition of 2,4-D, in the liquid MS medium and the utilization of L-tyrosol for chemical feeding enhanced salidroside production. Using a proper combination of culture condition and treatment, salidroside accumulation could reach 57.72 mg g(-1) dry weight, that was 5-10-fold higher than that detected in field-grown plants. The corresponding salidroside yield was 555.13 mg l(-1), a level suitable for cost effective commercial production to compensate the natural resource shortage of R. sachalinensis. (C) 2003 Elsevier B.V. All rights reserved
Cadmium response of the hairy root culture of the endangered species Adenophora lobophylla
We generated hairy root cultures from two closely related species, Adenophora lobophylla and A. potaninii (Campanulaeae) and carried out a comparative study on their cadmium (Cd) response. A. lobophylla is an endangered species while A. potaninii is widely distributed in the same habitat. Upon exposure to Cd concentrations higher than 50 muM, more extensive growth inhibition and higher Cd accumulation were detected in the hairy root of A. lobophylla. Cd treatment affected the protein content in both the species. Phytochelatins (PCs) have been isolated and characterized from the hairy roots for both species. They shared structure similarities but showed different accumulation kinetics. The content of reduced glutathione (GSH) and cysteine (Cys) differs in both the species and they show different changes upon Cd challenge. The results suggested that these two species might employ different strategy for Cd detoxification. A. lobophylla is capable of synthesizing high level of PCs while a Cd exclusion system and a tighter homeostasis mechanism(s) to maintain the cellular GSH level could have been evolved in A. potanini in additon to its capability of synthesizing PCs. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved
Supercritical Fluid Extraction of Seed Oil from Chinese Licorice Glycyrrhiza uralensis Fisch.): Chemical Composition and Antibacterial Activity
Seed oil from Glycyrrhiza uralensis Fisch. was extracted by supercritical fluid (CO2) extraction. The oil was analysed by GC-MS after methylation. Compounds were identified according to their mass spectra (EI, 70 eV) by comparison with authentic reference substances and literature data. Five fatty acids were identified, with linoleic acid (24.3%) and α-linolenic acid (25.51%) being the main constituents. The effects of extraction time, pressure, temperature and CO2 flow rate on seed oil yield were investigated. Results showed that, under dynamic extraction time of 1.5 h, pressure 30MPa, temperature 50 °C and CO2 flux of 10 kg h–1, the oil yield was 2.09% (m/m). The method was efficient for the extraction of this oil. Antibacterial activity of the oil was checked against Gram-negative and Gram-positive strains, evaluated by investigation of MIC and MBC. The seed oil of Glycyrrhiza uralensis did not exhibit an antibacterial effect against the tested strains in our test system.KEYWORDS: Fatty acid, methylation, GC-MS, SCFE-CO2, Glycyrrhiza uralensis Fisch., antibacterial activity
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