| 1. |
- Alvarado-Kristensson, Maria
(författare)
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A simple and fast method for fixation of cultured cell lines that preserves cellular structures containing gamma-tubulin
- 2018
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Ingår i: MethodsX. - : Elsevier BV. - 2215-0161. ; 5, s. 227-233
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Tidskriftsartikel (refereegranskat)abstract
- When using fluorescence microscope techniques to study cells, it is essential that the cell structure and contents are preserved after preparation of the samples, and that the preparation method employed does not create artefacts that can be perceived as cellular structure/components. γ-Tubulin forms filaments that in some cases are immunostained with an anti-γ-tubulin antibody, but this immunostaining is not reproducible [1,2]. In addition, the C terminal region of γ-tubulin (green fluorescence protein tagged [GFP]-γ-tubulin334––449) forms cytosolic GFP-labeled structures, which can easily be imaged in live cells but are not preserved in fixed cells [1,3]. The purpose of this study was to identify a fixation technique that preserves cellular constituents containing γ-tubulin. • This protocol describes a method that preserves γ-tubulin-containing structures in fixed cells.• The technique entails two-step fixation. A pre-fixation step using paraformaldehyde is followed by a final fixation and permeabilization step performed at −80 °C.• In comparison with other methodology for fixation [4–6], the technique presented here uses a short pre-fixation step with a mixture of paraformaldehyde and sucrose followed by a short fixation/permeabilization step with a mixture of methanol and acetone at −80 °C.
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| 2. |
- Alvarado-Kristensson, Maria
(författare)
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Ett nytt cellskelett i kampen mot cancer
- 2018
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Ingår i: Onkologi i Sverige : den oberoende tidningen för svensk cancervård. - 1653-1582. ; 5, s. 44-48
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- Forskare vid Lunds universitet har upptäckt ett cellskelett som ger struktur åt mito-kondrierna, cellens energifabriker. Skelettet är nödvändigt för mitokondriernas funktion, men forskarna fann även att cancerceller trots defekter utnyttjar skelettet för att kunna bibehålla sin energiproduktion – och därigenom överleva. Cellskelettet i mitokondrierna fungerar ungefär som ett armeringsnät och hjälper till att bibehålla cellens uppbyggnad och bidrar till stabiliteten i cellens olika rum. Det gör att olika molekyler lättare kan ta sig runt i cellen, skriver Maria Alvarado Kristensson, docent och forskare i molekylär patologi vid Lunds universitet.
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| 3. |
- Alvarado Kristensson, Maria, et al.
(författare)
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The Biology of the Nuclear Envelope and Its Implications in Cancer Biology
- 2019
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 20:10
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Forskningsöversikt (refereegranskat)abstract
- The formation of the nuclear envelope and the subsequent compartmentalization of the genome is a defining feature of eukaryotes. Traditionally, the nuclear envelope was purely viewed as a physical barrier to preserve genetic material in eukaryotic cells. However, in the last few decades, it has been revealed to be a critical cellular component in controlling gene expression and has been implicated in several human diseases. In cancer, the relevance of the cell nucleus was first reported in the mid-1800s when an altered nuclear morphology was observed in tumor cells. This review aims to give a current and comprehensive view of the role of the nuclear envelope on cancer first by recapitulating the changes of the nuclear envelope during cell division, second, by reviewing the role of the nuclear envelope in cell cycle regulation, signaling, and the regulation of the genome, and finally, by addressing the nuclear envelope link to cell migration and metastasis and its use in cancer prognosis.
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| 4. |
- Alvarado-kristensson, Maria
(författare)
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γ-tubulin as a signal-transducing molecule and meshwork with therapeutic potential
- 2018
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Ingår i: Signal Transduction and Targeted Therapy. - : Springer Science and Business Media LLC. - 2059-3635. ; 3
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Forskningsöversikt (refereegranskat)abstract
- Knowledge of γ-tubulin is increasing with regard to the cellular functions of this protein beyond its participation in microtubule nucleation. γ-Tubulin expression is altered in various malignancies, and changes in the TUBG1 gene have been found in patients suffering from brain malformations. This review recapitulates the known functions of γ-tubulin in cellular homeostasis and discusses the possible influence of the protein on disease development and cancer.
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| 5. |
- Lekmeechai, Sujinna, et al.
(författare)
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Helicobacter pylori Outer Membrane Vesicles Protect the Pathogen From Reactive Oxygen Species of the Respiratory Burst
- 2018
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Ingår i: Frontiers in Microbiology. - : Frontiers Media S.A.. - 1664-302X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Outer membrane vesicles (OMVs) play an important role in the persistence of Helicobacter pylori infection. Helicobacter OMVs carry a plethora of virulence factors, including catalase (KatA), an antioxidant enzyme that counteracts the host respiratory burst. We found KatA to be enriched and surface-associated in OMVs compared to bacterial cells. This conferred OMV-dependent KatA activity resulting in neutralization of H2O2 and NaClO, and rescue of surrounding bacteria from oxidative damage. The antioxidant activity of OMVs was abolished by deletion of KatA. In conclusion, enrichment of antioxidative KatA in OMVs is highly important for efficient immune evasion.
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| 6. |
- Lindström, Lisa, et al.
(författare)
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Characterization of gamma-tubulin filaments in mammalian cells
- 2018
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Ingår i: Biochimica et Biophysica Acta - Molecular Cell Research. - : Elsevier BV. - 0167-4889. ; 1865:1, s. 158-171
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Tidskriftsartikel (refereegranskat)abstract
- Overexpression of γ-tubulin leads to the formation of filaments, but nothing is known about such filaments with regard to possible presence in cells, structure and probable dynamics. Here, we used mammalian cell lines to investigate the ability of γ-tubulin to form filaments. We found that γ-tubulin produces fibers called γ-tubules in a GTP-dependent manner and that γ-tubules are made up of pericentrin and the γ-tubulin complex proteins 2, 3, 5 and 6. Furthermore, we noted that the number of cells with cytosolic γ-tubules is increased in non-dividing cells. Our experiments showed that γ-tubules are polar structures that have a low regrowth rate compared to microtubules. Also, we observed that γ-tubules were disassembled by treatment with cold, colcemid, citral dimethyl acetal, dimethyl fumarate or mutation of γ-tubulin GTPase domain, but were increased in number by treatment with taxol or by stable expression of the γ-tubulin1–333 GTPase domain. Our results demonstrate that γ-tubulin forms filaments, and such assembly is facilitated by the GTPase domain of γ-tubulin.
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| 7. |
- Lindström, Lisa, et al.
(författare)
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The GTPase domain of gamma-tubulin is required for normal mitochondrial function and spatial organization
- 2018
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 1:https://doi.org/10.1038/s42003-018-0037-3
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Tidskriftsartikel (refereegranskat)abstract
- In the cell, γ-tubulin establishes a cellular network of threads named the γ-string meshwork. However, the functions of this meshwork remain to be determined. We investigated the traits of the meshwork and show that γ-strings have the ability to connect the cytoplasm and the mitochondrial DNA together. We also show that γ-tubulin has a role in the maintenance of the mitochondrial network and functions as reduced levels of γ-tubulin or impairment of its GTPase domain disrupts the mitochondrial network and alters both their respiratory capacity and the expression of mitochondrial-related genes. By contrast, reduced mitochondrial number or increased protein levels of γ-tubulin DNA-binding domain enhanced the association of γ-tubulin with mitochondria. Our results demonstrate that γ-tubulin is an important mitochondrial structural component that maintains the mitochondrial network, providing mitochondria with a cellular infrastructure. We propose that γ-tubulin provides a cytoskeletal element that gives form to the mitochondrial network.
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| 8. |
- Lindström, Lisa, et al.
(författare)
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Therapeutic Targeting of Nuclear Gamma-Tubulin in RB1-negative Tumors.
- 2015
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Ingår i: Molecular Cancer Research. - 1557-3125. ; 13:7, s. 1073-1082
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Tidskriftsartikel (refereegranskat)abstract
- In addition to its cytosolic function, gamma-tubulin is a chromatin-associated protein. Reduced levels of nuclear gamma-tubulin increase the activity of E2 promoter-binding factors (E2F) and raise the levels of retinoblastoma (RB1) tumor suppressor protein. In tumor cells lacking RB1 expression, decreased gamma-tubulin levels induce cell death. Consequently, impairment of the nuclear activity of gamma-tubulin has been suggested as a strategy for targeted chemotherapy of RB1-deficient tumors; thus, tubulin inhibitors were tested to identify compounds that interfere with gamma-tubulin. Interestingly, citral increased E2F activity but impaired microtubule dynamics while citral analogs, like citral dimethyl acetal (CDA), increased E2F activity without affecting microtubules. The cytotoxic effect of CDA on tumor cells was attenuated by increased expression of either RB1 or gamma-tubulin, and increased by reduced levels of either RB1 or gamma-tubulin. Mechanistic study, in silico and in vitro, demonstrated that CDA prevents GTP binding to gamma-tubulin and suggested that the FDA approved drug dimethyl fumarate is also a gamma-tubulin inhibitor. Finally, in vivo growth of xenograft tumors carrying defects in the RB1 signaling pathway were inhibited by CDA treatment. These results demonstrate that inhibition of gamma-tubulin has the potential to specifically target tumor cells and may aid in the design of safer and more efficient chemotherapeutic regimes.
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| 9. |
- Mehdawi, Lubna M., et al.
(författare)
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A potential anti-tumor effect of leukotriene C4 through the induction of 15-hydroxyprostaglandin dehydrogenase expression in colon cancer cells
- 2017
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 8:21, s. 35033-35047
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. Cyclooxygenase-2, which plays a key role in the biosynthesis of prostaglandin E2 (PGE2), is often up-regulated in CRC and in other types of cancer. PGE2 induces angiogenesis and tumor cell survival, proliferation and migration. The tumor suppressor 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is a key enzyme in PGE2 catabolism, converting it into its inactive metabolite 15-keto- PGE2, and is often down-regulated in cancer. Interestingly, CRC patients expressing high levels of the cysteinyl leukotriene 2 (CysLT2) receptor have a good prognosis; therefore, we investigated a potential link between CysLT2 signaling and the tumor suppressor 15-PGDH in colon cancer cells. We observed a significant up-regulation of 15-PGDH after treatment with LTC4, a CysLT2 ligand, in colon cancer cells at both the mRNA and protein levels, which could be reduced by a CysLT2 antagonist or a JNK inhibitor. LTC4 induced 15-PGDH promoter activity via JNK/AP-1 phosphorylation. Furthermore, we also observed that LTC4, via the CysLT2/JNK signaling pathway, increased the expression of the differentiation markers sucrase-isomaltase and mucin-2 in colon cancer cells and that down-regulation of 15-PGDH totally abolished the observed increase in these markers. In conclusion, the restoration of 15-PGDH expression through CysLT2 signaling promotes the differentiation of colon cancer cells, indicating an anti-tumor effect of CysLT2 signaling.
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| 10. |
- Rosselló, Catalina Ana, et al.
(författare)
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γ-Tubulin⁻γ-Tubulin Interactions as the Basis for the Formation of a Meshwork
- 2018
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Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 19:10
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Forskningsöversikt (refereegranskat)abstract
- In cytoplasm, protein γ-tubulin joins with various γ-tubulin complex proteins (GCPs) to form a heterotetramer γ-tubulin small complex (γ-TuSC) that can grow into a ring-shaped structure called the γ-tubulin ring complex (γ-TuRC). Both γ-TuSC and γ-TuRC are required for microtubule nucleation. Recent knowledge on γ-tubulin with regard to its cellular functions beyond participation in its creation of microtubules suggests that this protein forms a cellular meshwork. The present review summarizes the recognized functions of γ-tubulin and aims to unite the current views on this protein.
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