scholarly journals Genome-wide analyses of XRN1-sensitive targets in osteosarcoma cells identifies disease-relevant transcripts containing G-rich motifs

2020 ◽  
Author(s):  
Amy L. Pashler ◽  
Benjamin P. Towler ◽  
Christopher I. Jones ◽  
Tom Burgess ◽  
Sarah F. Newbury

ABSTRACTXRN1 is a highly conserved exoribonuclease which degrades uncapped RNAs in a 5’-3’ direction. Degradation of RNAs by XRN1 is important in many cellular and developmental processes and is relevant to human disease. Studies in D. melanogaster demonstrate that XRN1 can target specific RNAs, which have important consequences for developmental pathways. Osteosarcoma is a malignancy of the bone and accounts for 2% of all paediatric cancers worldwide. 5 year survival of patients has remained static since the 1970s and therefore furthering our molecular understanding of this disease is crucial. Previous work has shown a downregulation of XRN1 in osteosarcoma cells, however the transcripts regulated by XRN1 which might promote osteosarcoma remain elusive. Here, we confirm reduced levels of XRN1 in osteosarcoma cell lines and patient samples and identify XRN1-sensitive transcripts in human osteosarcoma cells. Using RNA-seq in XRN1-knockdown SAOS-2 cells, we show that 1178 genes are differentially regulated. Using a novel bioinformatic approach, we demonstrate that 134 transcripts show characteristics of direct post-transcriptional regulation by XRN1. Long non-coding RNAs (lncRNAs) are enriched in this group suggesting that XRN1 normally plays an important role in controlling lncRNA expression in these cells. Among potential lncRNAs targeted by XRN1 is HOTAIR, which is known to be upregulated in osteosarcoma and contribute to disease progression. We have also identified G-rich and GU motifs in post-transcriptionally regulated transcripts which appear to sensitise them to XRN1 degradation. Our results therefore provide significant insights into the specificity of XRN1 in human cells which is relevant to disease.

2016 ◽  
Vol 11 (4) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Jose M. Moran ◽  
Olga Leal-Hernandez ◽  
Maria L. Canal-Macías ◽  
Raul Roncero-Martin ◽  
Rafael Guerrero-Bonmatty ◽  
...  

In this study, we evaluated the antiproliferative activity on two human osteosarcoma cell lines (MG-63 and Saos2) of oleuropein, an olive oil compound traditionally found in the Mediterranean diet. Oleuropein exhibited obvious cytotoxic effects on human osteosarcoma cells in a concentration- and time-dependent manner. Statistical analysis of IC50 by the Probit regression method suggested that oleuropein had similar toxic effects on both cell lines tested (IC50 range from 247.4–475.0 μM for MG63 cells and from 798.7–359.9 μM for Saos2 cells).


2019 ◽  
Vol 20 (23) ◽  
pp. 5864 ◽  
Author(s):  
Yuliang Wang ◽  
Abdiasis M. Hussein ◽  
Logeshwaran Somasundaram ◽  
Rithika Sankar ◽  
Damien Detraux ◽  
...  

microRNAs are ~22bp nucleotide non-coding RNAs that play important roles in the post-transcriptional regulation of gene expression. Many studies have established that microRNAs are important for cell fate choices, including the naïve to primed pluripotency state transitions, and their intermediate state, the developmentally suspended diapause state in early development. However, the full extent of microRNAs associated with these stage transitions in human and mouse remain under-explored. By meta-analysis of microRNA-seq, RNA-seq, and metabolomics datasets from human and mouse, we found a set of microRNAs, and importantly, their experimentally validated target genes that show consistent changes in naïve to primed transitions (microRNA up, target genes down, or vice versa). The targets of these microRNAs regulate developmental pathways (e.g., the Hedgehog-pathway), primary cilium, and remodeling of metabolic processes (oxidative phosphorylation, fatty acid metabolism, and amino acid transport) during the transition. Importantly, we identified 115 microRNAs that significantly change in the same direction in naïve to primed transitions in both human and mouse, many of which are novel candidate regulators of pluripotency. Furthermore, we identified 38 microRNAs and 274 target genes that may be involved in diapause, where embryonic development is temporarily suspended prior to implantation to uterus. The upregulated target genes suggest that microRNAs activate stress response in the diapause stage. In conclusion, we provide a comprehensive resource of microRNAs and their target genes involved in naïve to primed transition and in the paused intermediate, the embryonic diapause stage.


Author(s):  
Shubin Wang ◽  
Zongguang Li ◽  
Wei Liu ◽  
Guojun Wei ◽  
Naichun Yu ◽  
...  

Neohesperidin has anti-oxidative and anti-inflammatory properties and exerts extensive therapeutic effects on various cancers. In this study, the osteosarcoma cell lines were exposed to different concentrations of neohesperidin. Cell proliferation and viability were assessed by CCK-8 and colony-formation assays. The role of neohesperidin in cell cycle progression and apoptosis were analyzed by flow cytometry and western blotting. To identify autophagosomes and autolysosomes, we used a tandem GFP-mRFP-LC3B lentiviral construct. In addition, autophagy was evaluated by examining autophagosome formation using transmission electron microscopy. Intracellular reactive oxygen species (ROS) production was detected by fluorescence microscopy and flow cytometry. Subsequently, the activation of the ROS/JNK signaling pathway was investigated. Neohesperidin could inhibit proliferation and induce apoptosis in SJSA and HOS cells. The formation of autophagosomes indicated that autophagy occurred in neohesperidin-treated cells and the apoptotic effect of neohesperidin was significantly increased after the use of autophagy inhibitors. Subsequently, we found that neohesperidin-induced apoptosis and autophagy were related to the increase in ROS generation and were significantly inhibited by GSH. Moreover, neohesperidin induced activation of the c-Jun N-terminal kinase (JNK) signaling pathway and inhibition of JNK with SP600125 attenuated neohesperidin-induced apoptosis and autophagy simultaneously. Our data indicated that neohesperidin caused G2/M phase arrest and induced apoptosis and autophagy by activating the ROS/JNK pathway in human osteosarcoma cells, suggesting that neohesperidin is a potential drug candidate for the treatment of osteosarcomas.


2020 ◽  
Vol 2020 ◽  
pp. 1-23
Author(s):  
Huanhuan Lv ◽  
Chenxiao Zhen ◽  
Junyu Liu ◽  
Peng Shang

Osteosarcoma is the most common primary malignancy of the skeleton in children and adults. The outcomes of people with osteosarcomas are unsatisfied. β-Phenethyl isothiocyanate (PEITC) exhibits chemoprevention and chemotherapeutic activities against many human cancers. The molecular mechanism underlying its action on osteosarcoma is still unknown. This study was aimed at investigating the effect of PEITC on human osteosarcoma both in vitro and in vivo. The results showed that PEITC reduced cell viability, inhibited proliferation, and caused G2/M cell cycle arrest in four human osteosarcoma cell lines (MNNG/HOS, U-2 OS, MG-63, and 143B). Then, we found that PEITC altered iron metabolism related to the processes of iron import, storage, and export, which resulted in increased labile iron. Expectedly, PEITC caused oxidative stress as a consequence of GSH depletion-inducing ROS generation and lipid peroxidation. Multiple cell death modalities, including ferroptosis, apoptosis, and autophagy, were triggered in human osteosarcoma cells. Three MAPKs (ERK, p38, and JNK) were all activated after PEITC treatment; however, they presented different responses among the four human osteosarcoma cell lines. ROS generation was proved to be the major cause of PEITC-induced decreased proliferative potential, altered iron metabolism, cell death, and activated MAPKs in human osteosarcoma cells. In addition, PEITC also significantly delayed tumor growth in a xenograft osteosarcoma mouse model with a 30 mg/kg administration dose. In conclusion, this study reveals that PEITC simultaneously triggers ferroptosis, apoptosis, and autophagy in human osteosarcoma cells by inducing oxidative stress.


1989 ◽  
Vol 37 (7) ◽  
pp. 1069-1074 ◽  
Author(s):  
J C Randall ◽  
D C Morris ◽  
S Zeiger ◽  
K Masuhara ◽  
T Tsuda ◽  
...  

The presence and activity of alkaline phosphatase in SAOS-2 and TE-85 human osteosarcoma cells grown in culture were examined at the ultrastructural level. A monoclonal antibody raised against purified human bone osteosarcoma alkaline phosphatase was used to localize the enzyme in cultures of the osteosarcoma cells. Similar cultures were analyzed for alkaline phosphatase activity using an enzyme cytochemical method with cerium as the capture agent. Alkaline phosphatase was immunolocalized at the light microscopic level in an osteogenic sarcoma and ultrastructurally on the SAOS-2 cell membrane and the enclosing membrane of extracellular vesicular structures close to the cells. In contrast, the TE-85 cells were characterized by the absence of all but a few traces of immunolabeling at the cell surface. Enzyme cytochemical studies revealed strong alkaline phosphatase activity on the outer surface of the SAOS-2 cell membrane. Much lower enzyme activity was observed in the TE-85 cells. The results support biochemical data from previous studies and confirm that SAOS-2 cells have a significantly greater concentration of alkaline phosphatase at the plasma membrane.


2020 ◽  
Vol 20 ◽  
Author(s):  
Maura Argenziano ◽  
Alessandra Di Paola ◽  
Chiara Tortora ◽  
Daniela Di Pinto ◽  
Elvira Pota ◽  
...  

Background: Osteosarcoma is an aggressive bone tumor. Itrepresents the principal cause of cancer-associated death in children.Considering the recent findings on the role of iron in cancer, iron chelation has been investigated for its antineoplastic properties in many tumors. Deferasirox is the most used iron chelator compound and in previous studies showed an anticancer effectinhematologic and solid malignancies. Eltrombopag is a Thrombopoietin receptor used in thrombocytopenia, that also binds and mobilize iron. It demonstrated an effect in iron overload conditions and also in contrasting cancer cells proliferation. Objective: We analyzed the effects of Deferasirox and Eltrombopag in Human Osteosarcoma cells, in the attempt to identify other therapeutic approaches for this tumor. Methods: We cultured and treated withDeferasirox and Eltrombopag, alone and in combination, two human osteosarcoma cell lines, MG63 and 143B. After 72h exposure, we performed RTqPCR, Western Blotting, Iron Assay and cytofluorimetric assays to evaluate the effect on viability, apoptosis, cell cycle progression and ROS production. Results: The iron chelating properties of the two compounds are confirmed also in Osteosarcoma, but we did not observe any direct effect on tumor progression. Discussion: We tested Deferasirox and Eltrombopag, alone and in combination, in Human Osteosarcoma cells for the first time and demonstrated that their iron chelating activity does not influence biochemical pathways related to cancer progression and maintenance. Conclusion: Although further investigations on possible effects mediated by cells of the tumor microenvironment could be of great interest, in vitro iron chelation in Osteosarcoma does not impair tumor progression.


Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 52 ◽  
Author(s):  
Lucas Dias ◽  
Ana Batista de Carvalho ◽  
Sara Pinto ◽  
Gilberto Aquino ◽  
Mário Calvete ◽  
...  

In the present study, we developed a green epoxidation approach for the synthesis of the diastereomers of (−)-isopulegol benzyl ether epoxide using molecular oxygen as the oxidant and a hybrid manganese(III)-porphyrin magnetic reusable nanocomposite as the catalyst. High activity, selectivity, and stability were obtained, with up to four recycling cycles without the loss of activity and selectivity for epoxide. The anticancer effect of the newly synthesized isopulegol epoxide diastereomers was evaluated on a human osteosarcoma cell line (MG-63); both diastereomers showed similar in vitro potency. The measured IC50 values were significantly lower than those reported for other monoterpene analogues, rendering these epoxide isomers as promising anti-tumor agents against low prognosis osteosarcoma.


Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2665 ◽  
Author(s):  
Ziqi Yue ◽  
Xin Guan ◽  
Rui Chao ◽  
Cancan Huang ◽  
Dongfang Li ◽  
...  

Diallyl disulfide (DADs), a natural organic compound, is extracted from garlic and scallion and has anti-tumor effects against various tumors. This study investigated the anti-tumor activity of DADs in human osteosarcoma cells and the mechanisms. MG-63 cells were exposed to DADs (0, 20, 40, 60, 80, and 100 μM) for different lengths of time (24, 48, and 72 h). The CCK8 assay results showed that DADs inhibited osteosarcoma cell viability in a dose-and time-dependent manner. FITC-Annexin V/propidium iodide staining and flow cytometry demonstrated that the apoptotic ratio increased and the cell cycle was arrested at the G2/M phase as the DADs concentration was increased. A Western blot analysis was employed to detect the levels of caspase-3, Bax, Bcl-2, LC3-II/LC3-I, and p62 as well as suppression of the mTOR pathway. High expression of LC3-II protein revealed that DADs induced formation of autophagosome. Furthermore, DADs-induced apoptosis was weakened after adding 3-methyladenine, demonstrating that the DADs treatment resulted in autophagy-mediated death of MG-63 cells. In addition, DADs depressed p-mTOR kinase activity, and the inhibited PI3K/Akt/mTOR pathway increased DADs-induced apoptosis and autophagy. In conclusion, our results reveal that DADs induced G2/M arrest, apoptosis, and autophagic death of human osteosarcoma cells by inhibiting the PI3K/Akt/mTOR signaling pathway.


2021 ◽  
Vol 9 (9) ◽  
Author(s):  
Longjie Chen ◽  
Dinh Nguyen ◽  
Ryan Kaminsky ◽  
Jennifer Helfer ◽  
Rosemary Dziak

Cabozantinib (CBZ) N-(4-((6,7-dimethoxyquinolin-4-yl) oxy) phenyl)-N-(4-fluorophenyl) cyclopropane-1,1-dicarboxamide) (XL184), an inhibitor of MET and vascular endothelial growth factor receptor (VEGFR-2), is an agent approved for the treatment of several types of carcinoma such as medullary thyroid and renal. Recent studies are encouraging for the effectiveness of CBZ in the treatment of osteosarcoma. Because of the complex nature of the microenvironment of osteosarcoma cell sites, in order to better understand the direct effects of CBZ on osteosarcoma cells, in vitro studies were conducted with the human osteosarcoma cell line, G292. Experiments were focused on the effects of CBZ on cell metabolic activity, differentiation, and apoptosis as well as the modulation of responses to growth factors such as platelet-derived growth factor (PDGF) and insulin like growth factor (IGF-I). The results indicate that CBZ can increase the activity of caspase 3/7 as an indicator of apoptosis as well as decrease cellular activity, measured by MTT assay and differentiation assessed by alkaline phosphatase activity. The drug partially downregulated the effects of PDGF on MTT activity and had significant inhibitory effects on the G292 cells response to IGF-I and production of VEGF. This study presents original information on responses of G292 human osteosarcoma cells to the chemotherapy agent, CBZ, and provides in vitro data consistent with the potential therapeutic effects of this agent for osteosarcoma.


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