scholarly journals The Activity of Kv 11.1 Potassium Channel Modulates F-Actin Organization During Cell Migration of Pancreatic Ductal Adenocarcinoma Cells

Cancers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 135 ◽  
Author(s):  
Sagar Manoli ◽  
Stefano Coppola ◽  
Claudia Duranti ◽  
Matteo Lulli ◽  
Lara Magni ◽  
...  

Cell migration exerts a pivotal role in tumor progression, underlying cell invasion and metastatic spread. The cell migratory program requires f-actin re-organization, generally coordinated with the assembly of focal adhesions. Ion channels are emerging actors in regulating cell migration, through different mechanisms. We studied the role of the voltage dependent potassium channel KV 11.1 on cell migration of pancreatic ductal adenocarcinoma (PDAC) cells, focusing on its effects on f-actin organization and dynamics. Cells were cultured either on fibronectin (FN) or on a desmoplastic matrix (DM) with the addition of a conditioned medium produced by pancreatic stellate cells (PSC) maintained in hypoxia (Hypo-PSC-CM), to better mimic the PDAC microenvironment. KV11.1 was essential to maintain stress fibers in a less organized arrangement in cells cultured on FN. When PDAC cells were cultured on DM plus Hypo-PSC-CM, KV11.1 activity determined the organization of cortical f-actin into sparse and long filopodia, and allowed f-actin polymerization at a high speed. In both conditions, blocking KV11.1 impaired PDAC cell migration, and, on cells cultured onto FN, the effect was accompanied by a decrease of basal intracellular Ca2+ concentration. We conclude that KV11.1 is implicated in sustaining pro-metastatic signals in pancreatic cancer, through a reorganization of f-actin in stress fibers and a modulation of filopodia formation and dynamics.

2021 ◽  
Author(s):  
Erik S Linklater ◽  
Emily Duncan ◽  
Ke Jun Han ◽  
Algirdas Kaupinis ◽  
Mindaugas Valius ◽  
...  

Rab40b is a SOCS box containing protein that regulates the secretion of MMPs to facilitate extracellular matrix remodeling during cell migration. Here we show that Rab40b interacts with Cullin5 via the Rab40b SOCS domain. We demonstrate that loss of Rab40b/Cullin5 binding decreases cell motility and invasive potential, and show that defective cell migration and invasion stem from alteration to the actin cytoskeleton, leading to decreased invadopodia formation, decreased actin dynamics at the leading edge, and an increase in stress fibers. We also show that these stress fibers anchor at less dynamic, more stable focal adhesions. Mechanistically, changes in the cytoskeleton and focal adhesion dynamics are mediated in part by EPLIN, which we demonstrate to be a binding partner of Rab40b and a target for Rab40b/Cullin5 dependent localized ubiquitylation and degradation. Thus, we propose a model where the Rab40b/Cullin5 dependent ubiquitylation regulates EPLIN localization to promote cell migration and invasion by altering focal adhesion and cytoskeletal dynamics.


2002 ◽  
Vol 227 (6) ◽  
pp. 412-424 ◽  
Author(s):  
Imre L. Szabó ◽  
Rama Pai ◽  
Michael K. Jones ◽  
George R. Ehring ◽  
Hirofumi Kawanaka ◽  
...  

Repair of superficial gastric mucosal injury is accomplished by the process of restitution—migration of epithelial cells to restore continuity of the mucosal surface. Actin filaments, focal adhesions, and focal adhesion kinase (FAK) play crucial roles in cell motility essential for restitution. We studied whether epidermal growth factor (EGF) and/or indomethacin (IND) affect cell migration, actin stress fiber formation, and/or phosphorylation of FAK and tensin in wounded gastric monolayers. Human gastric epithelial monolayers (MKN 28 cells) were wounded and treated with either vehicle or 0.5 mM IND for 16 hr followed by EGF. EGF treatment significantly stimulated cell migration and actin stress fiber formation, and increased FAK localization to focal adhesions, and phosphorylation of FAK and tensin, whereas IND inhibited all these at the baseline and EGF-stimulated conditions. IND-induced inhibition of FAK phosphorylation preceded changes in actin polymerization, indicating that actin depolymerization might be the consequence of decreased FAK activity. In in vivo experiments, rats received either vehicle or IND (5 mg/kg i.g.), and 3 min later, they received water or 5% hypertonic NaCl; gastric mucosa was obtained at 1, 4, and 8 hr after injury. Four and 8 hr after hypertonic injury, FAK phosphorylation was induced in gastric mucosa compared with controls. IND pretreatment significantly delayed epithelial restitution in vivo, and reduced FAK phosphorylation and recruitment to adhesion points, as well as actin stress fiber formation in migrating surface epithelial cells. Our study indicates that FAK, tensin, and actin stress fibers are likely mediators of EGF-stimulated cell migration in wounded human gastric monolayers and potential targets for IND-induced inhibition of restitution.


2007 ◽  
Vol 18 (10) ◽  
pp. 3860-3872 ◽  
Author(s):  
Justin G. Peacock ◽  
Ann L. Miller ◽  
William D. Bradley ◽  
Olga C. Rodriguez ◽  
Donna J. Webb ◽  
...  

In migrating cells, actin polymerization promotes protrusion of the leading edge, whereas actomyosin contractility powers net cell body translocation. Although they promote F-actin–dependent protrusions of the cell periphery upon adhesion to fibronectin (FN), Abl family kinases inhibit cell migration on FN. We provide evidence here that the Abl-related gene (Arg/Abl2) kinase inhibits fibroblast migration by attenuating actomyosin contractility and regulating focal adhesion dynamics. arg−/− fibroblasts migrate at faster average speeds than wild-type (wt) cells, whereas Arg re-expression in these cells slows migration. Surprisingly, the faster migrating arg−/− fibroblasts have more prominent F-actin stress fibers and focal adhesions and exhibit increased actomyosin contractility relative to wt cells. Interestingly, Arg requires distinct functional domains to inhibit focal adhesions and actomyosin contractility. The kinase domain–containing Arg N-terminal half can act through the RhoA inhibitor p190RhoGAP to attenuate stress fiber formation and cell contractility. However, Arg requires both its kinase activity and its cytoskeleton-binding C-terminal half to fully inhibit focal adhesions. Although focal adhesions do not turn over efficiently in the trailing edge of arg−/− cells, the increased contractility of arg−/− cells tears the adhesions from the substrate, allowing for the faster migration observed in these cells. Together, our data strongly suggest that Arg inhibits cell migration by restricting actomyosin contractility and regulating its coupling to the substrate through focal adhesions.


2017 ◽  
Vol 28 (8) ◽  
pp. 1054-1065 ◽  
Author(s):  
Yu-Hung Lin ◽  
Yen-Yi Zhen ◽  
Kun-Yi Chien ◽  
I-Ching Lee ◽  
Wei-Chi Lin ◽  
...  

Nonmuscle myosin II (NM-II) is an important motor protein involved in cell migration. Incorporation of NM-II into actin stress fiber provides a traction force to promote actin retrograde flow and focal adhesion assembly. However, the components involved in regulation of NM-II activity are not well understood. Here we identified a novel actin stress fiber–associated protein, LIM and calponin-homology domains 1 (LIMCH1), which regulates NM-II activity. The recruitment of LIMCH1 into contractile stress fibers revealed its localization complementary to actinin-1. LIMCH1 interacted with NM-IIA, but not NM-IIB, independent of the inhibition of myosin ATPase activity with blebbistatin. Moreover, the N-terminus of LIMCH1 binds to the head region of NM-IIA. Depletion of LIMCH1 attenuated myosin regulatory light chain (MRLC) diphosphorylation in HeLa cells, which was restored by reexpression of small interfering RNA–resistant LIMCH1. In addition, LIMCH1-depleted HeLa cells exhibited a decrease in the number of actin stress fibers and focal adhesions, leading to enhanced cell migration. Collectively, our data suggest that LIMCH1 plays a positive role in regulation of NM-II activity through effects on MRLC during cell migration.


Pancreatology ◽  
2013 ◽  
Vol 13 (1) ◽  
pp. e10
Author(s):  
Abasi Ene-Obong ◽  
Andrew J. Clear ◽  
Alan G. Ramsay ◽  
Hemant M. Kocher

2021 ◽  
Author(s):  
Fernando R. Valencia ◽  
Eduardo Sandoval ◽  
Jian Liu ◽  
Sergey V. Plotnikov

ABSTRACTPlasticity of cell mechanics, which relies heavily on the spatiotemporal regulation of the actomyosin cytoskeleton, safeguards cells against mechanical damage. Yet, mechanisms of adaptive change in cell mechanics remain elusive. Here, we report a new mechanism whereby mechanically activated actin elongation factor mDia1 controls the dynamics of actin polymerization at focal adhesions, force bearing linkages between the actin cytoskeleton and extracellular matrix. By combining live-cell imaging with mathematical modelling, we show that actin polymerization at focal adhesions exhibits pulsatile dynamics where the spikes of mDia1 activity are triggered by cell-generated contractile forces. We show that suppression of mDia1-mediated actin polymerization at focal adhesions results in two-fold increase in mechanical tension on the stress fibers. This elevated tension leads to an increased frequency of spontaneous stress fiber damage and decreased efficiency of zyxin-mediated stress fiber repair. We conclude that tension-controlled actin polymerization at focal adhesions acts as a safety valve dampening excessive mechanical tension on the actin cytoskeleton and safeguarding stress fibers against mechanical damage.SUMMARYValencia et al. reports that stress fiber elongation at focal adhesion requires mDia1 activity, furthermore contractile forces trigger mDia1-dependent actin polymerization. mDia1-mediated actin polymerization acts as a safety valve to dampen mechanical stress and protect the cell from damage.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Dawei Jiang ◽  
Xiangfei Yuan ◽  
Jianqi Ni ◽  
Lan Shen ◽  
Min Cai ◽  
...  

Background. One of the microRNAs (miRNAs) known to be associated with cancer development is miR-607. The aim of this study is to investigate the clinical significance and diagnostic and prognostic value of miR-607 and to explore its potential role in pancreatic ductal adenocarcinoma (PDAC). Methods. The expression levels of miR-607 were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The correlation between miR-607 expression and clinical characteristics was analyzed by the Chi-square test. Overall survival (OS) and progression-free survival (PFS) were evaluated via the Kaplan–Meier method, and the association between miR-607 expression and OS was investigated by the Cox proportional hazard analysis. The diagnostic value was estimated via receiver operating characteristic (ROC) curve analysis. The effect of miR-607 overexpression on cell migration, invasion, and epithelial-mesenchymal transition (EMT) was determined by wound-healing, Transwell invasion, and Western blotting assays. Results. miR-607 levels were downregulated in PDAC tumor tissues compared with normal tissues. Also, low miR-607 levels were observed in serum samples from PDAC patients than that in healthy controls. The miR-607 level was found to be closely correlated with lymphatic metastasis and liver metastasis, perineural invasion, and OS and PFS, and the low miR-607 level was an independent prognostic factor for the poor OS of PDAC patients. Furthermore, the area under the curve (AUC) of serum miR-607 for discriminating PDAC patients was 0.785 with a sensitivity of 0.647 and a specificity of 0.772, which was better than those for CA19-9 (AUC: 0.702, sensitivity: 0.607, specificity: 0.736) and CEA (AUC: 0.648, sensitivity: 0.542, specificity: 0.670). The AUC (0.863), sensitivity (0.766), and specificity (0.831) of their combination in the diagnosis of PDAC were better than those for alone. Moreover, ectopic overexpression of miR-607 could inhibit cell migration and invasion of BxPc-3 and PANC-1 cells by decreasing EMT ability. Conclusions. Low serum miR-607 level may serve as a potential diagnostic and prognostic biomarker through regulation of tumor metastasis in PDAC patients.


2016 ◽  
Vol 34 (4_suppl) ◽  
pp. 211-211
Author(s):  
Emmanouil Fokas ◽  
Michael A Silva ◽  
Zenobia D'Costa ◽  
Robin Bockelmann ◽  
Zahir Soonawalla ◽  
...  

211 Background: Pancreatic ductal adenocarcinoma (PDAC) often presents an abundant desmoplastic stroma. We assessed the prognostic value of stroma density and activity in patients with resectable PDAC treated with surgery and adjuvant gemcitabine-based chemotherapy. Methods: FFPE-tissue originating from the pancreatectomy of 145 patients was immunohistochemicallystained for haematoxylin-eosin and Masson’s trichrome to assess stroma density, and alpha-smooth muscle actin (αSMA) expression for activated pancreatic stellate cells. Their expression was correlated with clinicopathological characteristics as well as overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS) and distant metastases free-survival (DMFS). Results: After a mean follow-up of 20 months (range, 2-69 months), the median OS was 21 months and the 3-year OS was 35.7 %. In multivariate analysis, highly-dense stroma was an independent prognostic parameter for OS (p = 0.001), PFS (p = 0.007), LPFS (p = 0.001) and DMFS (p = 0.002), while αSMA expression lacked significance. Interestingly, highly-dense stroma retained significance for the four clinical endpoints only in early (pT1-2) but not late (pT3-4) stage tumors. Additionally, late pT-stage (pT3-4), the presence of lymph node metastases (pN+ vs pN0), perineural/neural invasion PNI and adjuvant chemotherapy also correlated with prognosis in multivariate analysis. Conclusions: In summary, stroma density represents an independent prognostic marker in PDAC patients treated with adjuvant chemotherapy. Our findings highlight the complexity of desmoplasia and indicate that highly-dense stroma is associated with better outcome. Further validation of the prognostic value of stroma as a biomarker and its role in PDAC biology is warranted and will be performed in a prospective study.


Sign in / Sign up

Export Citation Format

Share Document