scholarly journals 1α,25(OH)2D3 Induces Actin Depolymerization in Endometrial Carcinoma Cells by Targeting RAC1 and PAK1

2016 ◽  
Vol 40 (6) ◽  
pp. 1455-1464 ◽  
Author(s):  
Ni Zeng ◽  
Madhuri S. Salker ◽  
Shaqiu Zhang ◽  
Yogesh Singh ◽  
Bing Shi ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Actin Cytoskeleton ◽  
Endometrial Carcinoma ◽  
Actin Polymerization ◽  
Carcinoma Cells ◽  
Filamentous Actin ◽  
Transcript Levels ◽  
Actin Depolymerization ◽  
Protein Levels ◽  
Ishikawa Cells

Background: Cell proliferation and motility require actin reorganization, which is under control of various signalling pathways including ras-related C3 botulinum toxin substrate 1 (RAC1), p21 protein-activated kinase 1 (PAK1) and actin related protein 2 (ARP2). Tumour cell proliferation is modified by 1α,25-Dihydroxy-Vitamin D3 (1α,25(OH)2D3), a steroid hormone predominantly known for its role in calcium and phosphorus metabolism. The present study explored whether 1α,25(OH)2D3 modifies actin cytoskeleton in Ishikawa cells, a well differentiated endometrial carcinoma cell line. Methods: To this end, actin cytoskeleton was visualized by confocal microscopy. Globular over filamentous actin ratio was determined utilizing Western blotting and flow cytometry, transcript levels by qRT-PCR and protein abundance by immunoblotting. Results: A 24 hour treatment with 1α,25(OH)2D3 (100 nM) significantly decreased RAC1 and PAK1 transcript levels and activity, decreased ARP2 protein levels and depolymerized actin. The effect of 1α,25(OH)2D3 on actin polymerization was mimicked by pharmacological inhibition of RAC1 and PAK1. Conclusions: 1α,25(OH)2D3 leads to disruption of RAC1 and PAK1 activity with subsequent actin depolymerization of endometrial carcinoma cells.

scholarly journals Autocrine stimulation of IGF1 in estrogen-induced growth of endometrial carcinoma cells: involvement of the mitogen-activated protein kinase pathway followed by up-regulation of cyclin D1 and cyclin E

2009 ◽  
Vol 16 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Hiroyasu Kashima ◽  
Tanri Shiozawa ◽  
Tsutomu Miyamoto ◽  
Akihisa Suzuki ◽  
Junko Uchikawa ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Protein Kinase ◽  
Cyclin D1 ◽  
Endometrial Carcinoma ◽  
Carcinoma Cells ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Ishikawa Cells ◽  
Autocrine Stimulation ◽  
Stimulation Of

To examine estrogen-induced growth mechanisms of endometrial carcinoma, we investigated the estrogen-induced activation of the mitogen-activated protein kinase (MAPK) pathway and cell cycle regulators. Estradiol (E2) treatment at concentrations of 10−8 M and 10−6 M to estrogen receptor (ER)-positive endometrial carcinoma Ishikawa cells for 24 h resulted in increased cell proliferation by 20% and 28% respectively. The E2-induced proliferation was associated with the activation of extracellular signal-regulated kinase (MAPK)3/1 and up-regulation of cyclin D1 and E, which were suppressed by the addition of an MAP2K inhibitor (U0126) or an ER antagonist (ICI 182 780). Then, our screening for estrogen-inducible growth factors identified that IGF1 was up-regulated remarkably by E2. Immunoprecipitation using conditioned medium of Ishikawa cells after E2 treatment confirmed the E2-induced secretion of IGF1 protein. Treatment with recombinant IGF1 stimulated cell proliferation in a dose-dependent fashion, in association with MAPK3/1 phosphorylation and up-regulation of cyclin D1 and E. These IGF1-induced responses were suppressed by treatment with MAP2K inhibitor or anti-IGF1 receptor antibody. Immunohistochemical staining confirmed the expression of activated MAPK3/1 in normal proliferative phase endometria and endometrial carcinomas, indicating the involvement of this pathway in actively proliferating endometrial tissues in vivo. These findings suggest that E2-induced proliferation of endometrial carcinoma cells is mediated by the MAPK3/1 pathway via autocrine stimulation of IGF1.

scholarly journals Coxiella burnetii Induces Reorganization of the Actin Cytoskeleton in Human Monocytes

1998 ◽  
Vol 66 (11) ◽  
pp. 5527-5533 ◽  
Author(s):  
Sonia Meconi ◽  
Véronique Jacomo ◽  
Patrice Boquet ◽  
Didier Raoult ◽  
Jean-Louis Mege ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Coxiella Burnetii ◽  
Actin Polymerization ◽  
Q Fever ◽  
Morphological Changes ◽  
Critical Role ◽  
Filamentous Actin ◽  
Cytoskeleton Reorganization ◽  
Membrane Protrusions ◽  
Actin Protrusions

ABSTRACT Coxiella burnetii, an obligate intracellular bacterium which survives in myeloid cells, causes Q fever in humans. We previously demonstrated that virulent C. burnetiiorganisms are poorly internalized by monocytes compared to avirulent variants. We hypothesized that a differential mobilization of the actin cytoskeleton may account for this distinct phagocytic behavior. Scanning electron microscopy demonstrated that virulent C. burnetii stimulated profound and polymorphic changes in the morphology of THP-1 monocytes, consisting of membrane protrusions and polarized projections. These changes were transient, requiring 5 min to reach their maximum extent and vanishing after 60 min of incubation. In contrast, avirulent variants of C. burnetii did not induce any significant changes in cell morphology. The distribution of filamentous actin (F-actin) was then studied with a specific probe, bodipy phallacidin. Virulent C. burnetii induced a profound and transient reorganization of F-actin, accompanied by an increase in the F-actin content of THP-1 cells. F-actin was colocalized with myosin in cell protrusions, suggesting that actin polymerization and the tension of actin-myosin filaments play a role in C. burnetii-induced morphological changes. In addition, contact between the cell and the bacterium seems to be necessary to induce cytoskeleton reorganization. Bacterial supernatants did not stimulate actin remodeling, and virulent C. burnetii organisms were found in close apposition with F-actin protrusions. The manipulation of the actin cytoskeleton by C. burnetiimay therefore play a critical role in the internalization strategy of this bacterium.

Lysophosphatidic acid-mediated augmentation of cardiomyocyte lipoprotein lipase involves actin cytoskeleton reorganization

2005 ◽  
Vol 288 (6) ◽  
pp. H2802-H2810 ◽  
Author(s):  
Thomas Pulinilkunnil ◽  
Ding An ◽  
Sanjoy Ghosh ◽  
Dake Qi ◽  
Girish Kewalramani ◽  
...  
Keyword(s):  
Actin Cytoskeleton ◽  
Lipoprotein Lipase ◽  
Lysophosphatidic Acid ◽  
Actin Polymerization ◽  
Contractile Function ◽  
Rho Kinase ◽  
Filamentous Actin ◽  
Membrane Translocation ◽  
Downstream Effector ◽  
Cytoskeleton Reorganization

The lipoprotein lipase (LPL)-augmenting property of lysophosphatidylcholine requires the formation of lysophosphatidic acid (LPA) ( J Mol Cell Cardiol 37: 931–938, 2004). Given that the actin cytoskeleton has been implicated in regulating cardiomyocyte LPL, we examined whether LPL secretion after LPA involves actin cytoskeleton reassembly. Incubation of myocytes with LPA (1–100 nM) increased basal and heparin-releasable LPL (HR-LPL), an effect that was independent of shifts in LPL mRNA. The influence of LPA on myocyte LPL was reflected at the coronary lumen, with substantial increases of the enzyme at this location. Incubation of myocytes with cytochalasin D not only blocked LPA-induced augmentation of HR-LPL but also abrogated filamentous actin formation. These effects of LPA were likely receptor mediated. Exposure of myocytes to LPA facilitated significant membrane translocation of RhoA and its downstream effector Rho kinase I (ROCK I), and blocking this effect with Y-27632 appreciably reduced basal and HR-LPL activity. Incubation of adipose tissue with LPA also significantly enhanced basal and HR-LPL activity, suggesting that sarcomeric actin likely has a limited role in influencing the LPL secretory function of LPA in the myocyte. Comparable to LPA, hyperglycemia also caused significant membrane translocation of RhoA and ROCK I in hearts isolated from diazoxide-treated animals, effects that were abrogated using insulin. Overall, our data suggest that comparable to hyperglycemia, LPA-induced increases in cardiac LPL occurred via posttranscriptional mechanisms and processes that likely required RhoA activation and actin polymerization. Whether this increase in LPL augments triglyceride deposition in the heart leading to eventual impairment in contractile function is currently unknown.

scholarly journals P-LAP/IRAP-induced cell proliferation and glucose uptake in endometrial carcinoma cells via insulin receptor signaling

BMC Cancer ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Kiyosumi Shibata ◽  
Hiroaki Kajiyama ◽  
Kazuhiko Ino ◽  
Akihiro Nawa ◽  
Seiji Nomura ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Insulin Receptor ◽  
Endometrial Carcinoma ◽  
Glucose Uptake ◽  
Carcinoma Cells ◽  
Receptor Signaling ◽  
Insulin Receptor Signaling

scholarly journals Mammalian Adenylyl Cyclase-associated Protein 1 (CAP1) Regulates Cofilin Function, the Actin Cytoskeleton, and Cell Adhesion

2013 ◽  
Vol 288 (29) ◽  
pp. 20966-20977 ◽  
Author(s):  
Haitao Zhang ◽  
Pooja Ghai ◽  
Huhehasi Wu ◽  
Changhui Wang ◽  
Jeffrey Field ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Actin Cytoskeleton ◽  
Hela Cells ◽  
Actin Polymerization ◽  
Actin Dynamics ◽  
Ras Signaling ◽  
Filamentous Actin ◽  
Camp Pathway

CAP (adenylyl cyclase-associated protein) was first identified in yeast as a protein that regulates both the actin cytoskeleton and the Ras/cAMP pathway. Although the role in Ras signaling does not extend beyond yeast, evidence supports that CAP regulates the actin cytoskeleton in all eukaryotes including mammals. In vitro actin polymerization assays show that both mammalian and yeast CAP homologues facilitate cofilin-driven actin filament turnover. We generated HeLa cells with stable CAP1 knockdown using RNA interference. Depletion of CAP1 led to larger cell size and remarkably developed lamellipodia as well as accumulation of filamentous actin (F-actin). Moreover, we found that CAP1 depletion also led to changes in cofilin phosphorylation and localization as well as activation of focal adhesion kinase (FAK) and enhanced cell spreading. CAP1 forms complexes with the adhesion molecules FAK and Talin, which likely underlie the cell adhesion phenotypes through inside-out activation of integrin signaling. CAP1-depleted HeLa cells also had substantially elevated cell motility as well as invasion through Matrigel. In summary, in addition to generating in vitro and in vivo evidence further establishing the role of mammalian CAP1 in actin dynamics, we identified a novel cellular function for CAP1 in regulating cell adhesion.

miR-486-3p Controls the Apoptosis of Endometrial Carcinoma Cells

2022 ◽  
Vol 12 (5) ◽  
pp. 1002-1007
Author(s):  
Donghua Wang ◽  
Xiaoli Liu ◽  
Lirong Cao ◽  
Shixiong Gong ◽  
Yi He ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Cell Migration ◽  
Endometrial Carcinoma ◽  
Real Time ◽  
Spectrophotometric Method ◽  
Real Time Pcr ◽  
Carcinoma Cells ◽  
Migration And Invasion ◽  
Invasive Capacity ◽  
Ec Cells

Our study aimed to discuss the mechanism of miR-486-3p in controlling the apoptosis of endometrial carcinoma (EC) cells. EC cells were divided into NC group, miR-486-3p mimic and miR-486-3p inhibitor group followed by analysis of miR-486-3p level by Real-time PCR, cell proliferation by spectrophotometric method, apoptosis by FCM, cell migration and invasion by Transwell analysis. EC cells showed reduced miR-486-3p level. The EC malignant biological behaviors could be prompted through retraining miR-486-3p level with increased EC cell invasive capacity. DDR1 was a target of miR-486-3p. The variation of tumor activity could be regulated through controlling DDR1 expression. In conclusion, the apoptotic and invasive characteristic of EC cells are restrained after overexpression of miR-486-3p in EC cells through targeting DDR1, indicating that miR-486-3p could be considered to be one kind of brand-new target for the treatment of EC.

scholarly journals Mechanisms of actin disassembly

2013 ◽  
Vol 24 (15) ◽  
pp. 2299-2302 ◽  
Author(s):  
William Brieher
Keyword(s):  
Actin Cytoskeleton ◽  
Cell Motility ◽  
Actin Filament ◽  
Actin Filaments ◽  
Actin Polymerization ◽  
Actin Depolymerization ◽  
Filament Dynamics ◽  
Physiological Demands ◽  
In Cells

The actin cytoskeleton is constantly assembling and disassembling. Cells harness the energy of these turnover dynamics to drive cell motility and organize cytoplasm. Although much is known about how cells control actin polymerization, we do not understand how actin filaments depolymerize inside cells. I briefly describe how the combination of imaging actin filament dynamics in cells and using in vitro biochemistry progressively altered our views of actin depolymerization. I describe why I do not think that the prevailing model of actin filament turnover—cofilin-mediated actin filament severing—can account for actin filament disassembly detected in cells. Finally, I speculate that cells might be able to tune the mechanism of actin depolymerization to meet physiological demands and selectively control the stabilities of different actin arrays.

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 ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Actin Cytoskeleton ◽  
Actin Polymerization ◽  
Metastatic Potential ◽  
New Drugs ◽  
Cell Stiffness ◽  
Migration And Invasion ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Metastatic Phenotype

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.

scholarly journals Novel Bradykinin Receptor Inhibitors Inhibit Proliferation and Promote the Apoptosis of Hepatocellular Carcinoma Cells by Inhibiting the ERK Pathway

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3915
Author(s):  
Yiou Wang ◽  
Bingxue Zhang ◽  
Yibing Huang ◽  
Wenjun Yao ◽  
Fei Tao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Proliferation ◽  
Liver Cancer ◽  
Carcinoma Cells ◽  
Receptor Expression ◽  
The Novel ◽  
Protein Levels ◽  
B1 Receptor ◽  
Common Cancer ◽  
Induced Apoptosis

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Studies have shown that bradykinin (BK) is highly expressed in liver cancer. We designed the novel BK receptor inhibitors J051-71 and J051-105, which reduced the viability of liver cancer cells and inhibited the formation of cancer cell colonies. J051-71 and J051-105 reduced cell proliferation and induced apoptosis in HepG2 and BEL-7402 cells, which may be due to the inhibition of the extracellular regulated protein kinase (ERK) signaling pathway. In addition, these BK receptor inhibitors reversed the cell proliferation induced by BK in HepG2 and BEL-7402 cells by downregulating B1 receptor expression. Inhibiting B1 receptor expression decreased the protein levels of p-ERK and reduced the malignant progression of HCC, providing a potential target for HCC therapy.

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