IN VITRO PICLORAM-INDUCED SOMATIC EMBRYOGENESIS FROM LEAFLET OF PRUNUS INCISE AND EXPRESSION PROFILE OF CDC2 GENE

This long term study demonstrates for the first time that it is possible to propagate embryogenic Vigna trilobata and to subsequently initiate the differentiation of embryos into complete plantlets. Initiation of callus was possible on 2,4-D. Somatic embryos differentiated on modified MS basal nutrient medium with 1.0 mg/l of 2,4-D and 0.5 mg/l of Kn. Sustained cell division resulted in globular and heart shape stages of somatic embryos. Transfer of embryos on to a fresh modified MS basal medium with 0.5 mg/l of Kn and 0.5 mg/l of GA3 helped them to attain maturation and germination. However, the propagation of cells, as well as the differentiation of embryos, were inhibited by a continuous application of these growth regulators. For this reason, a long period on medium lacking these growth regulators was necessary before the differentiation of embryos occurred again. The consequences for improving the propagation of embryogenic cultures in Vigna species are discussed. Key words: Pasture legume, Vigna trilobata, Globular, Heart shape, somatic embryogenesis D.O.I. 10.3329/ptcb.v19i1.4990 Plant Tissue Cult. & Biotech. 19(1): 89-99, 2009 (June)

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The warburg effect and tumour cell survival in human GBMs

Clinical & Investigative Medicine ◽

10.25011/cim.v30i4.2878 ◽

2007 ◽

Vol 30 (4) ◽

pp. 97 ◽

Cited By ~ 1

Author(s):

A Wolf ◽

J Mukherjee ◽

A Guha

Keyword(s):

Cytochrome C ◽

Cell Survival ◽

Expression Profile ◽

Tumour Cell ◽

Warburg Effect ◽

Glycolytic Enzymes ◽

Cytochrome C Release ◽

Apoptotic Pathway ◽

The Warburg Effect

Introduction: GBMs are resistant to apoptosis induced by the hypoxic microenvironment and standard therapies including radiation and chemotherapy. We postulate that the Warburg effect, a preferential glycolytic phenotype of tumor cells even under aerobic conditions, plays a role in these aberrant pro-survival signals. In this study we quantitatively examined the expression profile of hypoxia-related glycolytic genes within pathologically- and MRI-defined “centre” and “periphery” of GBMs. We hypothesize that expression of hypoxia-induced glycolytic genes, particularly hexokinase 2 (HK2), favours cell survival and modulates resistance to tumour cell apoptosis by inhibiting the intrinsic mitochondrial apoptotic pathway. Methods: GBM patients underwent conventional T1-weighted contrast-enhanced MRI and MR spectroscopy studies on a 3.0T GE scanner, prior to stereotactic sampling (formalin and frozen) from regions which were T1-Gad enhancing (“centre”) and T2-positive, T1-Gad negative (“periphery”). Real-time qRT-PCR was performed to quantify regional gene expression of glycolytic genes including HK2. In vitro functional studies were performed in U87 and U373 GBM cell lines grown in normoxic (21% pO2) and hypoxic (< 1%pO2) conditions, transfected with HK2 siRNA followed by measurement of cell proliferation (BrdU), apoptosis (activated caspase 3/7, TUNEL, cytochrome c release) and viability (MTS assay). Results: There exists a differential expression profile of glycolytic enzymes between the hypoxic center and relatively normoxic periphery of GBMs. Under hypoxic conditions, there is increased expression of HK2 at the mitochondrial membrane in GBM cells. In vitro HK2 knockdown led to decreased cell survival and increased apoptosis via the intrinsic mitochondrial pathway, as seen by increased mitochondrial release of cytochrome-C. Conclusions: Increased expression of HK2 in the centre of GBMs promotes cell survival and confers resistance to apoptosis, as confirmed by in vitro studies. In vivo intracranial xenograft studies with injection of HK2-shRNA are currently being performed. HK2 and possibly other glycolytic enzymes may provide a target for enhanced therapeutic responsiveness thereby improving prognosis of patients with GBMs.

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Cytokine expression profile of in vitro cultured endometrial stromal and epithelial cells during the window of implantation (WOI) – a promising tool for receptivity assessment

10.26226/morressier.573c1512d462b80296c9864d ◽

2016 ◽

Author(s):

Todor Chaushev

Keyword(s):

Epithelial Cells ◽

Expression Profile ◽

Cytokine Expression ◽

Cytokine Expression Profile ◽

Promising Tool

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Faculty Opinions recommendation of Human primordial germ cell commitment in vitro associates with a unique PRDM14 expression profile.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.725381857.793512105 ◽

2015 ◽

Author(s):

Florence Marlow

Keyword(s):

Germ Cell ◽

Expression Profile ◽

Primordial Germ Cell ◽

Cell Commitment

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Telomere Length in Norway Spruce during Somatic Embryogenesis and Cryopreservation

Plants ◽

10.3390/plants10020416 ◽

2021 ◽

Vol 10 (2) ◽

pp. 416

Author(s):

Tuija Aronen ◽

Susanna Virta ◽

Saila Varis

Keyword(s):

Somatic Embryogenesis ◽

Telomere Length ◽

Norway Spruce ◽

Genotypic Variation ◽

Production Capacity ◽

Stress Factors ◽

Embryo Production ◽

One Year ◽

Plant Telomeres

Telomeres i.e., termini of the eukaryotic chromosomes protect chromosomes during DNA replication. Shortening of telomeres, either due to stress or ageing is related to replicative cellular senescence. There is little information on the effect of biotechnological methods, such as tissue culture via somatic embryogenesis (SE) or cryopreservation on plant telomeres, even if these techniques are widely applied. The aim of the present study was to examine telomeres of Norway spruce (Picea abies (L.) Karst.) during SE initiation, proliferation, embryo maturation, and cryopreservation to reveal potential ageing or stress-related effects that could explain variation observed at SE process. Altogether, 33 genotypes from 25 families were studied. SE initiation containing several stress factors cause telomere shortening in Norway spruce. Following initiation, the telomere length of the embryogenic tissues (ETs) and embryos produced remains unchanged up to one year of culture, with remarkable genotypic variation. Being prolonged in vitro culture can, however, shorten the telomeres and should be avoided. This is achieved by successful cryopreservation treatment preserving telomere length. Somatic embryo production capacity of the ETs was observed to vary a lot not only among the genotypes, but also from one timepoint to another. No connection between embryo production and telomere length was found, so this variation remains unexplained.

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Barley somatic embryogenesis-an attempt to modify variation induced in tissue culture

Journal of Biological Research-Thessaloniki ◽

10.1186/s40709-021-00138-5 ◽

2021 ◽

Vol 28 (1) ◽

Author(s):

Renata Orłowska

Keyword(s):

Tissue Culture ◽

Somatic Embryogenesis ◽

Taguchi Method ◽

Culture Conditions ◽

Dna Demethylation ◽

Silver Ion ◽

Donor Plant ◽

In Vitro Tissue Culture ◽

Induced Variation

Abstract Background Somatic embryogenesis is a phenomenon carried out in an environment that generates abiotic stress. Thus, regenerants may differ from the source of explants at the morphological, genetic, and epigenetic levels. The DNA changes may be the outcome of induction media ingredients (i.e., copper and silver ions) and their concentrations and time of in vitro cultures. Results This study optimised the level of copper and silver ion concentration in culture media parallel with the induction medium longevity step towards obtaining barley regenerants via somatic embryogenesis with a minimum or maximum level of tissue culture-induced differences between the donor plant and its regenerants. The optimisation process is based on tissue culture-induced variation evaluated via the metAFLP approach for regenerants derived under varying in vitro tissue culture conditions and exploited by the Taguchi method. In the optimisation and verification experiments, various copper and silver ion concentrations and the different number of days differentiated the tested trials concerning the tissue culture-induced variation level, DNA demethylation, and de novo methylation, including symmetric (CG, CHG) and asymmetric (CHH) DNA sequence contexts. Verification of optimised conditions towards obtaining regenerants with minimum and maximum variability compared to donor plants proved useful. The main changes that discriminate optimised conditions belonged to DNA demethylation events with particular stress on CHG context. Conclusions The combination of tissue culture-induced variation evaluated for eight experimental trials and implementation of the Taguchi method allowed the optimisation of the in vitro tissue culture conditions towards the minimum and maximum differences between a source of tissue explants (donor plant) and its regenerants from somatic embryos. The tissue culture-induced variation characteristic is mostly affected by demethylation with preferences towards CHG sequence context.

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