scholarly journals Spatiotemporal Mislocalization of Nuclear Membrane-Associated Proteins in γ-Irradiation-Induced Senescent Cells

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 999
Author(s):  
Alena Svobodová Kovaříková ◽  
Eva Bártová ◽  
Aleš Kovařík ◽  
Emilie Lukášová
Keyword(s):  
Cell Lines ◽  
Cellular Senescence ◽  
Nuclear Membrane ◽  
Osteosarcoma Cell ◽  
Linc Complex ◽  
Protein Distribution ◽  
Γ Irradiation ◽  
Lamin B ◽  
Original Cell ◽  
Shrna Knockdown

Cellular senescence, induced by genotoxic or replication stress, is accompanied by defects in nuclear morphology and nuclear membrane-heterochromatin disruption. In this work, we analyzed cytological and molecular changes in the linker of nucleoskeleton and cytoskeleton (LINC) complex proteins in senescence triggered by γ-irradiation. We used human mammary carcinoma and osteosarcoma cell lines, both original and shRNA knockdown clones targeting lamin B receptor (LBR) and leading to LBR and lamin B (LB1) reduction. The expression status and integrity of LINC complex proteins (nesprin-1, SUN1, SUN2), lamin A/C, and emerin were analyzed by immunodetection using confocal microscopy and Western blot. The results show frequent mislocalization of these proteins from the nuclear membrane to cytoplasm and micronuclei and, in some cases, their fragmentation and amplification. The timing of these changes clearly preceded the onset of senescence. The LBR deficiency triggered neither senescence nor changes in the LINC protein distribution before irradiation. However, the cytological changes following irradiation were more pronounced in shRNA knockdown cells compared to original cell lines. We conclude that mislocalization of LINC complex proteins is a significant characteristic of cellular senescence phenotypes and may influence complex events at the nuclear membrane, including trafficking and heterochromatin attachment.

Lamin B receptor: role on chromatin structure, cellular senescence and possibly aging

2020 ◽  
Vol 477 (14) ◽  
pp. 2715-2720
Author(s):  
Susana Castro-Obregón
Keyword(s):  
Cellular Senescence ◽  
Nuclear Membrane ◽  
Chromatin Structure ◽  
Cholesterol Synthesis ◽  
Reductase Activity ◽  
Chimeric Protein ◽  
Nuclear Lamina ◽  
Lamin B ◽  
Inner Nuclear Membrane ◽  
Lamin B Receptor

The nuclear envelope is composed by an outer nuclear membrane and an inner nuclear membrane, which is underlain by the nuclear lamina that provides the nucleus with mechanical strength for maintaining structure and regulates chromatin organization for modulating gene expression and silencing. A layer of heterochromatin is beneath the nuclear lamina, attached by inner nuclear membrane integral proteins such as Lamin B receptor (LBR). LBR is a chimeric protein, having also a sterol reductase activity with which it contributes to cholesterol synthesis. Lukasova et al. showed that when DNA is damaged by ɣ-radiation in cancer cells, LBR is lost causing chromatin structure changes and promoting cellular senescence. Cellular senescence is characterized by terminal cell cycle arrest and the expression and secretion of various growth factors, cytokines, metalloproteinases, etc., collectively known as senescence-associated secretory phenotype (SASP) that cause chronic inflammation and tumor progression when they persist in the tissue. Therefore, it is fundamental to understand the molecular basis for senescence establishment, maintenance and the regulation of SASP. The work of Lukasova et al. contributed to our understanding of cellular senescence establishment and provided the basis that lead to the further discovery that chromatin changes caused by LBR reduction induce an up-regulated expression of SASP factors. LBR dysfunction has relevance in several diseases and possibly in physiological aging. The potential bifunctional role of LBR on cellular senescence establishment, namely its role in chromatin structure together with its enzymatic activity contributing to cholesterol synthesis, provide a new target to develop potential anti-aging therapies.

scholarly journals Induction of a Massive Endoplasmic Reticulum and Perinuclear Space Expansion by Expression of Lamin B Receptor Mutants and the Related Sterol Reductases TM7SF2 and DHCR7

2010 ◽  
Vol 21 (2) ◽  
pp. 354-368 ◽  
Author(s):  
Monika Zwerger ◽  
Thorsten Kolb ◽  
Karsten Richter ◽  
Iakowos Karakesisoglou ◽  
Harald Herrmann
Keyword(s):  
Endoplasmic Reticulum ◽  
Nuclear Envelope ◽  
Cell Lines ◽  
Nuclear Membrane ◽  
Cultured Cells ◽  
Membrane Separation ◽  
Reductase Activity ◽  
Nuclear Pore ◽  
Lamin B ◽  
Lamin B Receptor

Lamin B receptor (LBR) is an inner nuclear membrane protein involved in tethering the nuclear lamina and the underlying chromatin to the nuclear envelope. In addition, LBR exhibits sterol reductase activity. Mutations in the LBR gene cause two different human diseases: Pelger-Huët anomaly and Greenberg skeletal dysplasia, a severe chrondrodystrophy causing embryonic death. Our study aimed at investigating the effect of five LBR disease mutants on human cultured cells. Three of the tested LBR mutants caused a massive compaction of chromatin coincidental with the formation of a large nucleus-associated vacuole (NAV) in several human cultured cell lines. Live cell imaging and electron microscopy revealed that this structure was generated by the separation of the inner and outer nuclear membrane. During NAV formation, nuclear pore complexes and components of the linker of nucleoskeleton and cytoskeleton complex were lost in areas of membrane separation. Concomitantly, a large number of smaller vacuoles formed throughout the cytoplasm. Notably, forced expression of the two structurally related sterol reductases transmembrane 7 superfamily member 2 and 7-dehydrocholesterol reductase caused, even in their wild-type form, a comparable phenotype in susceptible cell lines. Hence, LBR mutant variants and sterol reductases can severely interfere with the regular organization of the nuclear envelope and the endoplasmic reticulum.

scholarly journals Anti-Metastatic and Anti-Angiogenic Effects of Curcumin Analog DK1 on Human Osteosarcoma Cells In Vitro

2021 ◽  
Vol 14 (6) ◽  
pp. 532
Author(s):  
Muhammad Nazirul Mubin Aziz ◽  
Nurul Fattin Che Rahim ◽  
Yazmin Hussin ◽  
Swee Keong Yeap ◽  
Mas Jaffri Masarudin ◽  
...  
Keyword(s):  
Cell Lines ◽  
Safety Profile ◽  
Quantitative Polymerase Chain Reaction ◽  
Tube Formation ◽  
Osteosarcoma Cell ◽  
Curcumin Analog ◽  
Human Osteosarcoma ◽  
Human Osteosarcoma Cells ◽  
Human Osteosarcoma Cell

Osteosarcoma (OS) is a life-threatening malignant bone tumor associated with poor prognosis among children. The survival rate of the patient is still arguably low even with intensive treatment provided, plus with the inherent side effects from the chemotherapy, which gives more unfavorable outcomes. Hence, the search for potent anti-osteosarcoma agent with promising safety profile is still on going. Natural occurring substance like curcumin has gained a lot of attention due to its splendid safety profile as well as it pharmacological advantages such as anti-metastasis and anti-angiogenesis. However, natural curcumin was widely known for its poor cellular uptake, which undermines all potential that it possesses. This prompted the development of synthetically synthesized curcuminoid analog, known as (Z)-3-hydroxy-1-(2-hydroxyphenyl)-3-phenylprop-2- en-1-one (DK1). In this present study, in vitro scratch assay, transwell migration/invasion assay, HUVEC tube formation assay, and ex vivo rat aortic ring assays were performed in order to investigate the anti-metastatic and anti-angiogenic potential of DK1. For further comprehension of DK1 mechanism on human osteosarcoma cell lines, microarray gene expression analysis, quantitative polymerase chain reaction (qPCR), and proteome profiler were adopted, providing valuable forecast from the expression of important genes and proteins related to metastasis and angiogenesis. Based on the data gathered from the bioassays, DK1 was able to inhibit the metastasis and angiogenesis of human osteosarcoma cell lines by significantly reducing the cell motility, number of migrated and invaded cells as well as the tube formation and micro-vessels sprouting. Additionally, DK1 also has significantly regulated several cancer pathways involved in OS proliferation, metastasis, and angiogenesis such as PI3K/Akt and NF-κB in both U-2 OS and MG-63. Regulation of PI3K/Akt caused up-regulation of genes related to metastasis inhibition, namely, PTEN, FOXO, PLK3, and GADD45A. Meanwhile, NF-κB pathway was regulated by mitigating the expression of NF-κB activator such as IKBKB and IKBKE in MG-63, whilst up-regulating the expression of NF-κB inhibitors such as NFKBIA and NFKBIE in U-2 OS. Finally, DK1 also has successfully hindered the metastatic and angiogenic capability of OS cell lines by down-regulating the expression of pro-metastatic genes and proteins like MMP3, COL11A1, FGF1, Endoglin, uPA, and IGFBP2 in U-2 OS. Whilst for MG-63, the significantly down-regulated oncogenes were Serpin E1, AKT2, VEGF, uPA, PD-ECGF, and Endoglin. These results suggest that curcumin analog DK1 may serve as a potential new anti-osteosarcoma agent due to its anti-metastatic and anti-angiogenic attributes.

scholarly journals Correction to: Afatinib is active in osteosarcoma cell lines

2020 ◽  
Vol 146 (10) ◽  
pp. 2719-2719
Author(s):  
Marlid Cruz-Ramos ◽  
Yessica Zamudio-Cuevas ◽  
Daniel Medina-Luna ◽  
Karina Martínez-Flores ◽  
Gabriela Martínez-Nava ◽  
...  
Keyword(s):  
Cell Lines ◽  
Osteosarcoma Cell

scholarly journals LncRNA SNHG15 contributes to doxorubicin resistance of osteosarcoma cells through targeting the miR-381-3p/GFRA1 axis

2020 ◽  
Vol 15 (1) ◽  
pp. 871-883
Author(s):  
Jinshan Zhang ◽  
Dan Rao ◽  
Haibo Ma ◽  
Defeng Kong ◽  
Xiaoming Xu ◽  
...  
Keyword(s):  
Cell Lines ◽  
Noncoding Rna ◽  
Xenograft Model ◽  
Inhibitory Effect ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells

AbstractBackgroundOsteosarcoma is a common primary malignant bone cancer. Long noncoding RNA small nucleolar RNA host gene 15 (SNHG15) has been reported to play an oncogenic role in many cancers. Nevertheless, the role of SNHG15 in the doxorubicin (DXR) resistance of osteosarcoma cells has not been fully addressed.MethodsCell Counting Kit-8 assay was conducted to measure the half-maximal inhibitory concentration value of DXR in osteosarcoma cells. Western blotting was carried out to examine the levels of autophagy-related proteins and GDNF family receptor alpha-1 (GFRA1). Quantitative reverse transcription-polymerase chain reaction was performed to determine the levels of SNHG15, miR-381-3p, and GFRA1. The proliferation of osteosarcoma cells was measured by MTT assay. The binding sites between miR-381-3p and SNHG15 or GFRA1 were predicted by Starbase bioinformatics software, and the interaction was confirmed by dual-luciferase reporter assay. Murine xenograft model was established to validate the function of SNHG15 in vivo.ResultsAutophagy inhibitor 3-methyladenine sensitized DXR-resistant osteosarcoma cell lines to DXR. SNHG15 was upregulated in DXR-resistant osteosarcoma tissues and cell lines. SNHG15 knockdown inhibited the proliferation, DXR resistance, and autophagy of osteosarcoma cells. MiR-381-3p was a direct target of SNHG15, and GFRA1 bound to miR-381-3p in osteosarcoma cells. SNHG15 contributed to DXR resistance through the miR-381-3p/GFRA1 axis in vitro. SNHG15 depletion contributed to the inhibitory effect of DXR on osteosarcoma tumor growth through the miR-381-3p/GFRA1 axis in vivo.ConclusionsSNHG15 enhanced the DXR resistance of osteosarcoma cells through elevating the autophagy via targeting the miR-381-3p/GFRA1 axis. Restoration of miR-381-3p expression might be an underlying therapeutic strategy to overcome the DXR resistance of osteosarcoma.

scholarly journals Characterization of dormancy in osteosarcoma cell lines cultured in 3D

Bone Reports ◽  
2021 ◽  
Vol 14 ◽  
pp. 100898
Author(s):  
Camille Jubelin ◽  
Denis Cochonneau ◽  
Javier Munoz-Garcia ◽  
Emilie Moranton ◽  
Marie-Françoise Heymann ◽  
...  
Keyword(s):  
Cell Lines ◽  
Osteosarcoma Cell

The influence of etoposide and meloxicam on canine (D-17) and human (U-2 OS) osteosarcoma cell lines

2015 ◽  
Vol 152 (1) ◽  
pp. 69
Author(s):  
D. Poradowski ◽  
B. Obmin′ ska-Mrukowicz ◽  
R. Ciaputa ◽  
M. Kandefer-Gola ◽  
M. Nowak ◽  
...  
Keyword(s):  
Cell Lines ◽  
Osteosarcoma Cell

scholarly journals Establishment and characterization of human osteosarcoma cell lines with different pulmonary metastatic potentials

2009 ◽  
Vol 61 (1-2) ◽  
pp. 37-44 ◽  
Author(s):  
Xiang Chen ◽  
Tong-Tao Yang ◽  
Wei Wang ◽  
Hong-Hui Sun ◽  
Bao-An Ma ◽  
...  
Keyword(s):  
Cell Lines ◽  
Osteosarcoma Cell ◽  
Human Osteosarcoma ◽  
Human Osteosarcoma Cell
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