MEK inhibition preferentially suppresses anchorage‐independent growth in osteosarcoma cells and decreases tumors in vivo

AbstractIn this study, we identified the multifaceted effects of atezolizumab, a specific monoclonal antibody against PD-L1, in tumor suppression except for restoring antitumor immunity, and investigated the promising ways to improve its efficacy. Atezolizumab could inhibit the proliferation and induce immune-independent apoptosis of osteosarcoma cells. With further exploration, we found that atezolizumab could impair mitochondria of osteosarcoma cells, resulting in increased release of reactive oxygen species and cytochrome-c, eventually leading to mitochondrial-related apoptosis via activating JNK pathway. Nevertheless, the excessive release of reactive oxygen species also activated the protective autophagy of osteosarcoma cells. Therefore, when we combined atezolizumab with autophagy inhibitors, the cytotoxic effect of atezolizumab on osteosarcoma cells was significantly enhanced in vitro. Further in vivo experiments also confirmed that atezolizumab combined with chloroquine achieved the most significant antitumor effect. Taken together, our study indicates that atezolizumab can induce mitochondrial-related apoptosis and protective autophagy independently of the immune system, and targeting autophagy is a promising combinatorial approach to amplify its cytotoxicity.

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

Open Life Sciences ◽

10.1515/biol-2020-0086 ◽

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.

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Potential Antimetastatic Effect of Timosaponin AIII against Human Osteosarcoma Cells through Regulating the Integrin/FAK/Cofilin Axis

Pharmaceuticals ◽

10.3390/ph14030260 ◽

2021 ◽

Vol 14 (3) ◽

pp. 260

Author(s):

Yi-Hsien Hsieh ◽

Wen-Hung Hsu ◽

Shun-Fa Yang ◽

Chung-Jung Liu ◽

Ko-Hsiu Lu ◽

...

Keyword(s):

Integrin Αvβ3 ◽

Migration And Invasion ◽

Steroidal Saponin ◽

Αvβ3 Integrin ◽

Osteosarcoma Cells ◽

Inhibitory Effects ◽

Human Osteosarcoma ◽

Human Osteosarcoma Cells ◽

Timosaponin Aiii

Timosaponin AIII (TSAIII) is a steroidal saponin which demonstrates anti-tumour activities. However, the effect of TSAIII on human osteosarcoma cells remains largely unknown. In this study, we demonstrated that TSAIII exerted a significant inhibitory effect on the distribution of cytoskeletal F-actin and cytoskeletal-related proteins, which contributed to the suppression of cell migration and invasion, without inhibiting cell growth or apoptosis. In the synergistic inhibitory analysis, cotreatment of TSAIII with αVβ3 integrin inhibitor [Cyclo(RGDyK)] or focal adhesion kinase (FAK) inhibitor (PF-573228) exerted greater synergistic inhibitory effects on the expression of Intergin αVβ3/FAK/cofilin axis, thus inhibiting the migration and invasion capacities of human osteosarcoma cells. TSAIII was demonstrated to significantly inhibit the pulmonary metastasis formation of human osteosarcoma cells in vivo in metastasis animal models. These findings reveal the inhibitory effects of TSAIII on the metastasis progression of human osteosarcoma cells and the regulation of integrin-αVβ3-FAK-Src and TESK1/p-cofilin mediated cytoskeletal F-actin pathway. Therefore, TSAIII might represent a novel strategy for the auxiliary treatment of human osteosarcoma cells.

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Knockdown of lncRNA GHET1 inhibits osteosarcoma cells proliferation, invasion, migration and EMT in vitro and in vivo

Cancer Biomarkers ◽

10.3233/cbm-181863 ◽

2018 ◽

Vol 23 (4) ◽

pp. 589-601 ◽

Cited By ~ 10

Author(s):

Wei Yang ◽

Zhiming Shan ◽

Xinfang Zhou ◽

Liangqun Peng ◽

Chongyang Zhi ◽

...

Keyword(s):

Osteosarcoma Cells

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Tumor Suppressor Function of miR-127-3p and miR-376a-3p in Osteosarcoma Cells

Cancers ◽

10.3390/cancers11122019 ◽

2019 ◽

Vol 11 (12) ◽

pp. 2019 ◽

Cited By ~ 6

Author(s):

Joerg Fellenberg ◽

Burkhard Lehner ◽

Heiner Saehr ◽

Astrid Schenker ◽

Pierre Kunz

Keyword(s):

Tumor Suppressor ◽

Therapeutic Strategies ◽

High Dose ◽

Osteosarcoma Cell ◽

Tumor Suppressor Function ◽

Osteosarcoma Cells ◽

Aberrant Expression ◽

Suppressor Function

Since the introduction of high-dose chemotherapy about 35 years ago, survival rates of osteosarcoma patients have not been significantly improved. New therapeutic strategies replacing or complementing conventional chemotherapy are therefore urgently required. MicroRNAs represent promising targets for such new therapies, as they are involved in the pathology of multiple types of cancer, and aberrant expression of several miRNAs has already been shown in osteosarcoma. In this study, we identified silencing of miR-127-3p and miR-376a-3p in osteosarcoma cell lines and tissues and investigated their role as potential tumor suppressors in vitro and in vivo. Transfection of osteosarcoma cells (n = 6) with miR-127-3p and miR-376a-3p mimics significantly inhibited proliferation and reduced the colony formation capacity of these cells. In contrast, we could not detect any influence of miRNA restoration on cell cycle and apoptosis induction. The effects of candidate miRNA restoration on tumor engraftment and growth in vivo were analyzed using a chicken chorioallantoic membrane (CAM) assay. Cells transfected with mir-127-3p and miR-376a-3p showed reduced tumor take rates and tumor volumes and a significant decrease of the cumulative tumor volumes to 41% and 54% compared to wildtype cells. The observed tumor suppressor function of both analyzed miRNAs indicates these miRNAs as potentially valuable targets for the development of new therapeutic strategies for the treatment of osteosarcoma.

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HDAC6 inhibitor WT161 performs antitumor effect on osteosarcoma and synergistically interacts with 5-FU

Bioscience Reports ◽

10.1042/bsr20203905 ◽

2021 ◽

Author(s):

Jun Sun ◽

Wei Wu ◽

Xiaofeng Tang ◽

Feifei Zhang ◽

Cheng Ju ◽

...

Keyword(s):

Dependent Manner ◽

Osteosarcoma Cells ◽

Synergistic Inhibition ◽

Proliferative Effect ◽

Xenograft Models ◽

Hdac6 Inhibitor ◽

Underlying Mechanisms ◽

Induced Apoptosis

Background: WT161, as a selective HDAC6 inhibitor, has been shown to play anti-tumor effects on several kinds of cancers. The aim of this study is to explore the roles of WT161 in osteosarcoma and its underlying mechanisms. Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were established to evaluate the anti-proliferative effect of WT161 in vivo. Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein level of PTEN and decreased the phosphorylation level of AKT. More importantly, WT161 show synergistic inhibition with 5-FU on osteosarcoma cells in vitro and in vivo. Conclusions: These results indicate that WT161 inhibits the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

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HDAC6 Inhibitor WT161 Performs Antitumor Effect on Ostersarcoma and Synergistically Interacts with 5-FU

10.21203/rs.3.rs-49194/v1 ◽

2020 ◽

Author(s):

Jun Sun ◽

Xiaofeng Tang ◽

Feifei Zhang ◽

Cheng Ju ◽

Renfeng Liu ◽

...

Keyword(s):

Osteosarcoma Cell ◽

Dependent Manner ◽

Osteosarcoma Cells ◽

Proliferative Effect ◽

Xenograft Models ◽

Hdac6 Inhibitor ◽

Underlying Mechanisms ◽

Induced Apoptosis

Abstract Background: WT161 as a new selective HDAC6 inhibitor has been shown to play anti-tumor effects on multiple myeloma and breast cancer. However, the role of WT161 in osteosarcoma remains unclear. The aim of this study is to explore the role of WT161 in osteosarcoma and its underlying mechanisms.Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were esatablished to evaluate the anti-proliferative effect of WT161 in vivo.Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein expression level of PTEN and decreased the phosphorylation level of AKT. Notably, WT161 shows synergistically inhibitory effects on osteosarcoma cell combined with 5-FU. Animal experiment results show WT161 inhibits the growth of osteosarcoma tumor and further illustrates that WT161 and 5-FU have a synergistic efficiency in osteosarcoma.Conclusions: These results indicate that WT161 inhibiting the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

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Selectively Targeting Breast Cancer Stem Cells by 8-Quinolinol and Niclosamide

10.21203/rs.3.rs-686641/v1 ◽

2021 ◽

Author(s):

Patricia Cámara-Sánchez ◽

Zamira V. Díaz-Riascos ◽

Natalia García-Aranda ◽

Petra Gener ◽

Joaquin Seras-Franzoso ◽

...

Keyword(s):

Breast Cancer ◽

Stem Cells ◽

Cancer Stem Cells ◽

Cell Viability ◽

Cancer Cells ◽

Cell Lines ◽

Breast Cancer Subtype ◽

Anchorage Independent Growth ◽

Tnbc Cell

Abstract Background Cancer maintenance, metastatic dissemination and drug-resistance are sustained by cancer stem cells (CSCs). Triple negative breast cancer (TNBC) is the breast cancer subtype with the highest numbers of CSCs and poorest prognosis. Here, we aimed to identify potential drugs targeting CSCs to be further employed in combination with standard chemotherapy in TNBC treatment. Methods The anti-CSC efficacy of up to 17 small-drugs was tested in TNBC cell lines using cell viability assays on differentiated cancer cells and CSCs. Then, the effect of 2 selected drugs (8-quinolinol -8Q- and niclosamide -NCS-) in the cancer stemness hallmarks were evaluated using mammosphere growth, cell invasion, migration and anchorage-independent growth assays. Changes in the expression of stemness genes upon 8Q or NCS treatment were also evaluated. Moreover, the potential synergism of 8Q and NCS with PTX on the CSC proliferation and on stemness-related signaling pathways was evaluated using TNBC cell lines, CSC-reporter sublines, and CSCenriched mammospheres. Finally, the efficacy of the NCS in combination with PTX was analyzed in vivo using an orthotopic mice model of MDA-MB-231 cells. Results Among all tested drug candidates, 8Q and NCS showed remarkable specific anti-CSC activity in terms of CSC viability, migration, invasion and anchorage independent growth reduction in vitro. Moreover, specific 8Q/PTX and NCS/PTX ratios at which both drugs displayed a synergistic effect in different TNBC cell lines were identified. The solely use of PTX increased the relative presence of CSCs in TNBC cells, whereas the combination with 8Q and NCS counteracted this pro-CSC activity of PTX whilst significantly reducing cell viability. In vivo, the combination of NCS with PTX reduced tumor growth, and limited the dissemination of the disease by reducing the circulating tumor cells and the incidence of lung metastasis. Conclusions The combination of 8Q and NCS with PTX at established ratios inhibits both, the proliferation of differentiated cancer cells and the viability of CSCs, opening a way to more efficacious TNBC treatments.

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LncRNA GAS5 suppresses the proliferation and invasion of osteosarcoma cells via the miR-23a-3p/PTEN/PI3K/AKT pathway

10.21203/rs.3.rs-26945/v2 ◽

2020 ◽

Author(s):

Jianmin Liu ◽

Ming Chen ◽

Longyang Ma ◽

Xingbo Dang ◽

Gongliang Du

Keyword(s):

Tumor Suppressor ◽

Tumor Growth ◽

Akt Pathway ◽

Osteosarcoma Cell ◽

Osteosarcoma Cells ◽

Cell Behaviors ◽

Human Osteosarcoma ◽

Proliferation And Invasion

Abstract Background: Accumulating evidence has shown that lncRNA growth arrest special 5 (GAS5) is a well‑known tumor suppressor in the pathogenesis of a variety of human cancers. However, the detailed role of GAS5 in osteosarcoma is largely unclear. Here, we explore the role of GAS5 in progression of osteosarcoma. Methods: The expression level of GAS5 was detected in human osteosarcoma tissues and matched adjacent tissues, as well as osteosarcoma cell lines and non-malignant osteoblast cells. Then, in vitro gain- and loss-of-function experiments, with the pcDNA-GAS5 expression vector and GAS5-siRNA, were performed in U2OS and HOS cells to determine the effect of GAS5 on osteosarcoma cell proliferation and invasion. Subsequently, we searched potential miRNA targets with bioinformatics analysis and confirmed their interaction by using luciferase reporter gene and RNA pull-down assays. The function and mechanism of miR-23a-3p in proliferation and invasion was also investigated in U2OS and HOS cells. Furthermore, rescue experiments were performed to verify the involvement of miR-23a-3p and its target gene in GAS5-mediated cell behaviors. Finally, a xenograft nude mouse model was established by subcutaneous injection with U2OS cells overexpressing GAS5 or not, and the effect of GAS5 on tumor growth in vivo was evaluated. Results: GAS5 was downregulated in human osteosarcoma tissues and cell lines. Overexpression of GAS5 could significantly suppress, and downregulation of GAS5 promoted, proliferation and invasion of osteosarcoma cells. GAS5 could directly bind with and downregulated miR-23a-3p that post-transcriptionally downregulated the tumor suppressor PTEN and positively regulated proliferation and invasion of osteosarcoma cells. Rescue experiments confirmed the involvement of miR-23a-3p and PTEN in GAS5-mediated cell behaviors by modifying the phosphatidylinositol-3-kinases/protein-serine-threonine kinase (PI3K/AKT) pathway. GAS5 could inhibit tumor growth in vivo . Conclusion: GAS5 functions as a competing endogenous RNA , sponging miR-23a-3p, to promote PTEN expression and suppress cell growth and invasion in osteosarcoma by regulating the PI3K/AKT pathway.

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