scholarly journals Cytoskeletal Actin Structure in Osteosarcoma Cells Determines Metastatic Phenotype via Regulating Cell Stiffness, Migration, and Transmigration

2021 ◽  
Vol 43 (3) ◽  
pp. 1255-1266
Author(s):  
Kouji Kita ◽  
Kunihiro Asanuma ◽  
Takayuki Okamoto ◽  
Eiji Kawamoto ◽  
Koichi Nakamura ◽  
...  

Osteosarcoma is the most common primary malignant bone tumor. The cause of death due to osteosarcoma is typically a consequence of metastasis to the lung. Controlling metastasis leads to improved prognosis for osteosarcoma patients. The cell stiffness of several tumor types is involved in metastatic potential; however, it is unclear whether the metastatic potential of osteosarcoma depends on cell stiffness. In this study, we analyzed the cell stiffness of the low metastatic Dunn cell line and its highly metastatic LM8 subline, and compared actin organization, cell proliferation, and metastasis. Actin cytoskeleton, polymerization, stiffness, and other cellular properties were analyzed. The organization of the actin cytoskeleton was evaluated by staining F-actin with Alexa Fluor 488 phalloidin. Cell stiffness was measured using Atomic Force Microscopy (AFM). Cell proliferation, migration, invasion, and adhesion were also evaluated. All experiments were performed using mouse osteosarcoma cell lines cultured in the absence and presence of cytochalasin. In LM8 cells, actin polymerization was strongly suppressed and actin levels were significantly lower than in Dunn cells. Stiffness evaluation revealed that LM8 cells were significantly softer than Dunn. Young’s modulus images showed more rigid fibrillar structures were present in Dunn cells than in LM8 cells. LM8 cells also exhibited a significantly higher proliferation. The migration and invasion potential were also higher in LM8 cells, whereas the adhesion potential was higher in Dunn cells. The administration of cytochalasin resulted in actin filament fragmentation and decreased actin staining intensity and cell stiffness in both LM8 and Dunn cells. Cells with high metastatic potential exhibited lower actin levels and cell stiffness than cells with low metastatic potential. The metastatic phenotype is highly correlated to actin status and cell stiffness in osteosarcoma cells. These results suggest that evaluation of actin dynamics and cell stiffness is an important quantitative diagnostic parameter for predicting metastatic potential. We believe that these parameters represent new reliable quantitative indicators that can facilitate the development of new drugs against metastasis.

2019 ◽  
Vol 30 (7) ◽  
pp. 887-898 ◽  
Author(s):  
Claude N. Holenstein ◽  
Aron Horvath ◽  
Barbara Schär ◽  
Angelina D. Schoenenberger ◽  
Maja Bollhalder ◽  
...  

Osteosarcoma is the most frequent primary tumor of bone and is characterized by its high tendency to metastasize in lungs. Although treatment in cases of early diagnosis results in a 5-yr survival rate of nearly 60%, the prognosis for patients with secondary lesions at diagnosis is poor, and their 5-yr survival rate remains below 30%. In the present work, we have used a number of analytical methods to investigate the impact of increased metastatic potential on the biophysical properties and force generation of osteosarcoma cells. With that aim, we used two paired osteosarcoma cell lines, with each one comprising a parental line with low metastatic potential and its experimentally selected, highly metastatic form. Mechanical characterization was performed by means of atomic force microscopy, tensile biaxial deformation, and real-time deformability, and cell traction was measured using two-dimensional and micropost-based traction force microscopy. Our results reveal that the low metastatic osteosarcoma cells display larger spreading sizes and generate higher forces than the experimentally selected, highly malignant variants. In turn, the outcome of cell stiffness measurements strongly depends on the method used and the state of the probed cell, indicating that only a set of phenotyping methods provides the full picture of cell mechanics.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zehua Zhang ◽  
Fei Dai ◽  
Fei Luo ◽  
Wenjie Wu ◽  
Shuai Zhang ◽  
...  

AbstractOsteosarcoma is a malignant osteoblastic tumor that can gravely endanger the lives and health of children and adolescents. Therefore, there is an urgent need to explore new biomarkers for osteosarcoma and determine new targeted therapies to improve the efficacy of osteosarcoma treatment. Diaphanous related formin 3 (DIAPH3) promotes tumorigenesis in hepatocellular carcinoma and lung adenocarcinoma, suggesting that DIAPH3 may be a target for tumor therapy. To date, there have been no reports on the function of DIAPH3 in osteosarcoma. DIAPH3 protein expression in osteosarcoma tissues and healthy bone tissues adjacent to cancer cells was examined by immunohistochemical staining. DIAPH3 mRNA expression correlates with overall survival and reduced disease-free survival. DIAPH3 protein is upregulated in osteosarcoma tissues, and its expression is significantly associated with tumor size, tumor stage, node metastasis, and distant metastasis. Functional in vitro experiments revealed that DIAPH3 knockdown suppressed cell proliferation and suppressed cell migration and invasion of osteosarcoma cell lines MG-63 and HOS. Functional experiments demonstrated that DIAPH3 knockdown inhibited subcutaneous tumor growth and lung metastasis in vivo. In conclusion, DIAPH3 expression can predict the clinical outcome of osteosarcoma. In addition, DIAPH3 is involved in the proliferation and metastasis of osteosarcoma, and as such, DIAPH3 may be a potential therapeutic target for osteosarcoma.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Andoni Garitano-Trojaola ◽  
Ana Sancho ◽  
Ralph Götz ◽  
Patrick Eiring ◽  
Susanne Walz ◽  
...  

AbstractThe presence of FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is one of the most frequent mutations in acute myeloid leukemia (AML) and is associated with an unfavorable prognosis. FLT3 inhibitors, such as midostaurin, are used clinically but fail to entirely eradicate FLT3-ITD + AML. This study introduces a new perspective and highlights the impact of RAC1-dependent actin cytoskeleton remodeling on resistance to midostaurin in AML. RAC1 hyperactivation leads resistance via hyperphosphorylation of the positive regulator of actin polymerization N-WASP and antiapoptotic BCL-2. RAC1/N-WASP, through ARP2/3 complex activation, increases the number of actin filaments, cell stiffness and adhesion forces to mesenchymal stromal cells (MSCs) being identified as a biomarker of resistance. Midostaurin resistance can be overcome by a combination of midostaruin, the BCL-2 inhibitor venetoclax and the RAC1 inhibitor Eht1864 in midostaurin-resistant AML cell lines and primary samples, providing the first evidence of a potential new treatment approach to eradicate FLT3-ITD + AML.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1376
Author(s):  
Concettina Cappadone ◽  
Emil Malucelli ◽  
Maddalena Zini ◽  
Giovanna Farruggia ◽  
Giovanna Picone ◽  
...  

Magnesium is an essential nutrient involved in many important processes in living organisms, including protein synthesis, cellular energy production and storage, cell growth and nucleic acid synthesis. In this study, we analysed the effect of magnesium deficiency on the proliferation of SaOS-2 osteosarcoma cells. When quiescent magnesium-starved cells were induced to proliferate by serum addition, the magnesium content was 2–3 times lower in cells maintained in a medium without magnesium compared with cells growing in the presence of the ion. Magnesium depletion inhibited cell cycle progression and caused the inhibition of cell proliferation, which was associated with mTOR hypophosphorylation at Serine 2448. In order to map the intracellular magnesium distribution, an analytical approach using synchrotron-based X-ray techniques was applied. When cell growth was stimulated, magnesium was mainly localized near the plasma membrane in cells maintained in a medium without magnesium. In non-proliferating cells growing in the presence of the ion, high concentration areas inside the cell were observed. These results support the role of magnesium in the control of cell proliferation, suggesting that mTOR may represent an important target for the antiproliferative effect of magnesium. Selective control of magnesium availability could be a useful strategy for inhibiting osteosarcoma cell growth.


2018 ◽  
Vol Volume 11 ◽  
pp. 8409-8420 ◽  
Author(s):  
Runsang Pan ◽  
Zhixu He ◽  
Wanyuan Ruan ◽  
Sun Li ◽  
Hui Chen ◽  
...  

2021 ◽  
Vol 12 (2) ◽  
pp. 467-473
Author(s):  
Tonglei Chen ◽  
Zhenshi Chen ◽  
Xiaoning Lian ◽  
Weidong Wu ◽  
Lei Chu ◽  
...  

2020 ◽  
Vol 19 ◽  
pp. 153303382094321
Author(s):  
Rui Gu ◽  
Xiaodong Li ◽  
Xiaowei Yan ◽  
Zhen Feng ◽  
Aixin Hu

Circular RNAs are a recently discovered subclass of endogenous noncoding RNAs that have been confirmed to play an important role in various pathophysiological processes. However, the underlying function of circular RNAs in osteosarcoma still remains unclear. We aimed to comprehend the function of circ_0032462 in osteosarcoma, as it has been predicted to be highly expressed in osteosarcoma cells. Using real-time polymerase chain reaction, we verified the elevated expression of circ_0032462 in osteosarcoma cells than normal cells. Functional validation experiments revealed that circ_0032462 overexpression promoted proliferation, migration, and invasion in osteosarcoma cells, whereas circ_0032462 silencing was observed to inhibit cancer cell progression (proliferation, migration, and invasion). Furthermore, we found that circ_0032462 upregulated the messenger RNA and protein expression level of kinesin family member 3B. In addition, kinesin family member 3B inhibition was found to inhibit circ_0032462-induced enhanced osteosarcoma cell progression. circ_0032462 overexpression was observed to reverse circ_0032462 silencing-induced inhibitory effect on osteosarcoma cell progression. Overall, our research revealed the function of circ_0032462 in osteosarcoma progression, which might serve as a novel chemotherapeutic target for osteosarcoma.


2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Ying Jiang ◽  
Chunlei Zhou ◽  
Qiang Gao ◽  
Zhi-Qi Yin ◽  
Jingwen Wang ◽  
...  

Aberrant expression of FAM64A was correlated with cell proliferation in various cancer types. We examined the expression of FAM64A and the upstream gene miR-493 in OS. The functions of miR-493 were revealed through extensive experiments. We found an increase of FAM64A gene and protein in OS tissues. Overexpression of FAM64A resulted in promoting tumor proliferation, migration, and invasion. The miR-493 targeted and negatively regulated FAM64A. Our data showed that upregulation of FAM64A in OS correlated with poor prognosis.


2019 ◽  
Vol 9 (9) ◽  
pp. 1245-1249
Author(s):  
Huanzhi Ma ◽  
Jian Wang ◽  
Jun Shi ◽  
Wei Zhang ◽  
Dongsheng Zhou

Osteosarcoma (OS) seriously affects human health. miR-124 expression is closely related to osteosarcoma, but its specific mechanism remains unclear. Our study intends to evaluate miR-124’s effect on osteosarcoma. MG-63 cells were transfected with miR-124 mimics/NC followed by analysis of miR-124 expression by real-time PCR, cell proliferation by CCK8 assay, cell apoptosis by flow cytometry as well as the level of caveolin-1 (CAV1) by Western blot. miR-124 was significantly lower and CAV1 was increased in the four osteosarcoma cells than those in normal osteoblasts (P < 0.05). miR-124 mimics transfection significantly reduced CAV1 level and cell number (P < 0.05) and increased cell apoptosis rate (P < 0.05). Moreover, miR-124 inhibitor significantly promoted the relative luciferase activity in pmirGLO-CAV1-3′UTR-wt-transfected cells (P < 0.05). miR-124 affects osteosarcoma cell proliferation and apoptosis via targeting CAV1.


Author(s):  
Feng Jiang ◽  
Yan Shi ◽  
Hong Lu ◽  
Guojun Li

Armadillo repeat-containing protein 8 (ARMC8) plays an important role in regulating cell migration, proliferation, tissue maintenance, signal transduction, and tumorigenesis. However, the expression pattern and role of ARMC8 in osteosarcoma are still unclear. In this study, our aims were to examine the effects of ARMC8 on osteosarcoma and to explore its underlying mechanism. Our results demonstrated that ARMC8 was overexpressed in osteosarcoma cell lines. Knockdown of ARMC8 significantly inhibited osteosarcoma cell proliferation in vitro and markedly inhibited xenograft tumor growth in vivo. ARMC8 silencing also suppressed the epithelial‐mesenchymal transition (EMT) phenotype, as well as inhibited the migration and invasion of osteosarcoma cells. Furthermore, knockdown of ARMC8 obviously inhibited the expression of β-catenin, c-Myc, and cyclin D1 in MG-63 cells. In conclusion, this report demonstrates that ARMC8 silencing inhibits proliferation and invasion of osteosarcoma cells. Therefore, ARMC8 may play an important role in the development and progression of human osteosarcoma and may represent a novel therapeutic target in the treatment of osteosarcoma.


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