Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cell migration”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed1994

Mesangial cell migration precedes proliferation in Habu snake venom-induced glomerular injury.

BACKGROUND: Mesangial cells migrate in response to platelet released products in vitro (Am J Pathol 1991;138:859). Cell migration, in addition to proliferation might play a role in cell remodeling during the course of proliferative glomerular disease. EXPERIMENTAL DESIGN: In this study, we examined mesangial cell migration in vivo in a platelet-dependent model of proliferative glomerulonephritis induced by Habu snake venom. Mesangial cell migration was assessed by phenotypic identification and temporal location of mesangial cells within glomerular lesions in serial time studies from 8 to 48 hours after Habu snake venom. Autoradiography of [3H]thymidine incorporation into cells was employed to identify and temporally separate cell division and proliferation from cell motility and other related events. RESULTS: Early (8-hour) lesions consisted of microaneurysms devoid of mesangial cells. By 24 hours, glomeruli showed mesangial cells at the margins of lesions adjacent to intact glomerular tufts, followed by the presence of clusters of cells at 30 and 36 hours. By 48 hours, most lesions were filled with proliferating mesangial cells. Cells containing [3H]thymidine were rarely observed until 30 hours, at which point they were found in advanced lesions. Marginating cells did not contain [3H]thymidine, suggesting that the location of these cells was not related to cell division but rather to migration. Platelet depletion eliminated platelets from lesions and substantially retarded mesangial cell migration into glomerular lesions indicating mesangial cell migration is, in part, dependent on platelets or their secretory products. CONCLUSIONS: These studies show that mesangial cells can migrate in vivo and suggest that cell migration is an important early step in cell redistribution and remodeling during glomerular injury in this model of proliferative glomerulonephritis.

Animals↗
PubMed2005

Proteolysis of cortactin by calpain regulates membrane protrusion during cell migration.

Calpain 2 regulates membrane protrusion during cell migration. However, relevant substrates that mediate the effects of calpain on protrusion have not been identified. One potential candidate substrate is the actin binding protein cortactin. Cortactin is a Src substrate that drives actin polymerization by activating the Arp2/3 complex and also stabilizes the cortical actin network. We now provide evidence that proteolysis of cortactin by calpain 2 regulates membrane protrusion dynamics during cell migration. We show that cortactin is a calpain 2 substrate in fibroblasts and that the preferred cleavage site occurs in a region between the actin binding repeats and the alpha-helical domain. We have generated a mutant cortactin that is resistant to calpain proteolysis but retains other biochemical properties of cortactin. Expression of the calpain-resistant cortactin, but not wild-type cortactin, impairs cell migration and increases transient membrane protrusion, suggesting that calpain proteolysis of cortactin limits membrane protrusions and regulates migration in fibroblasts. Furthermore, the enhanced protrusion observed with the calpain-resistant cortactin requires both the Arp2/3 binding site and the Src homology 3 domain of cortactin. Together, these findings suggest a novel role for calpain-mediated proteolysis of cortactin in regulating membrane protrusion dynamics during cell migration.

Actins↗
PubMed2005

Involvement of aquaporin-4 in astroglial cell migration and glial scar formation.

Aquaporin-4, the major water-selective channel in astroglia throughout the central nervous system, facilitates water movement into and out of the brain. Here, we identify a novel role for aquaporin-4 in astroglial cell migration, as occurs during glial scar formation. Astroglia cultured from the neocortex of aquaporin-4-null mice had similar morphology, proliferation and adhesion, but markedly impaired migration determined by Transwell migration efficiency (18+/-2 vs 58+/-4% of cells migrated towards 10% serum in 8 hours; P<0.001) and wound healing rate (4.6 vs 7.0 microm/hour speed of wound edge; P<0.001) compared with wild-type mice. Transwell migration was similarly impaired (25+/-4% migrated cells) in wild-type astroglia after approximately 90% reduction in aquaporin-4 protein expression by RNA inhibition. Aquaporin-4 was polarized to the leading edge of the plasma membrane in migrating wild-type astroglia, where rapid shape changes were seen by video microscopy. Astroglial cell migration was enhanced by a small extracellular osmotic gradient, suggesting that aquaporin-4 facilitates water influx across the leading edge of a migrating cell. In an in vivo model of reactive gliosis and astroglial cell migration produced by cortical stab injury, glial scar formation was remarkably impaired in aquaporin-4-null mice, with reduced migration of reactive astroglia towards the site of injury. Our findings provide evidence for the involvement of aquaporin-4 in astroglial cell migration, which occurs during glial scar formation in brain injury, stroke, tumor and focal abscess.

Animals↗
PubMed2005

Contact stimulation of prostate cancer cell migration: the role of gap junctional coupling and migration stimulated by heterotypic cell-to-cell contacts in determination of the metastatic phenotype of Dunning rat prostate cancer cells.

BACKGROUND INFORMATION: Motile activity of tumour cells is regarded as a critical factor determining their metastatic potential. We have shown previously that contrary to the majority of normal cells, homotypic contacts between some tumour cells, among them low metastatic (AT-2) and highly metastatic (MAT-LyLu) rat prostate cancer cells, increase the speed of their movements. The aim of the present study was to determine the effect of heterotypic cell-to-cell contacts on the migration of rat prostate cancer cells differing in metastatic potential, and to correlate it with the intensity of homo- and heterologous gap junctional coupling. RESULTS: MAT-LyLu and AT-2 cells moving on the surface of fibroblasts displayed significantly greater cell displacement than those moving on plastic substrata. This effect correlated with the polarization (contact guidance) and increased speed of cell movements. However, in contrast with the migration on plastic substrata, where MAT-LyLu cells displayed considerably higher motility than AT-2 cells, no differences between both cell lines were observed on the surface of fibroblasts. On the other hand, in contrast with AT-2, Mat-LyLu cells displayed extensive homologous coupling mediated by connexin43 and were able to couple with normal fibroblasts. CONCLUSION: Heterotypic contacts between migrating prostatic cancer cells and normal fibroblasts can strongly stimulate their migration during invasion; however, this effect does not correlate with the gap junctional coupling between cancer cells and normal fibroblasts.

Animals↗
PubMed1996

The C. elegans gene vab-8 guides posteriorly directed axon outgrowth and cell migration.

The assembly of the nervous system in the nematode C. elegans requires the directed migrations of cells and growth comes along the anteroposterior and dorsoventral body axis. We show here that the gene vab-8 is essential for most posteriorly directed migrations of cells and growth cones. Mutations in vab-8 disrupt fourteen of seventeen posteriorly directed migrations, but only two of seventeen anteriorly directed and dorsoventral migrations. For two types of neurons that extend axons both anteriorly and posteriorly, vab-8 mutations disrupt only the growth of the posteriorly directed axon. vab-8 encodes two genetic activities that function in the guidance of different migrations. Our results suggest that most posteriorly directed cell and growth cone migrations are guided by a common mechanism involving the vab-8 gene.

Alleles↗
PubMed1999

Synthetic alphaVbeta3 antagonists inhibit insulin-like growth factor-I-stimulated smooth muscle cell migration and replication.

Porcine aortic smooth cells respond to insulin-like growth factor-I (IGF-I) with increases in DNA synthesis and cell migration. Because ligand occupancy of the alphaVbeta3 integrin has been shown to be necessary for IGF-I to stimulate maximal increases in both processes, we determined whether synthetic alphaVbeta3 antagonists could inhibit IGF-I-stimulated actions on this cell type. Low-molecular-weight compounds that had been selected based on their ability to compete with vitronectin for binding to purified human alphaVbeta3 in vitro were analyzed for their ability to compete with 125I-kistrin (a known ligand for porcine alphaVbeta3) for binding to porcine alphaVbeta3. Nine compounds were screened, and five were found to be potent competitive inhibitors. The most potent compound, SC-69000, resulted in 88% competition at 10(-7) M and was nearly equipotent with echistatin. The compounds that were the most potent inhibitors of kistrin binding were tested for their capacity to inhibit the cell migration response to IGF-I. Three compounds caused between 81-88% inhibition of IGF-I-stimulated migration at 10(-7) M. To determine whether these compounds could inhibit other IGF-I-stimulated actions, their ability to inhibit IGF-I-stimulated [3H]-thymidine incorporation into DNA was analyzed. The four compounds that were the most potent inhibitors of cell migration also inhibited IGF-I-stimulated DNA replication. IGF-I stimulates the synthesis of IGF binding protein-5 by these cells. Preincubation with the four most active compounds also resulted in significant inhibition of the ability of IGF-I to stimulate IGF binding protein-5 synthesis. AlphaVbeta3 occupancy by the ligand vitronectin has been shown to enhance the capacity of IGF-I to activate its receptor tyrosine kinase. The four most active compounds were shown to inhibit IGF-I-stimulated IGF-I receptor autophosphorylation. These findings suggest that blockade of ligand occupancy of the alphaVbeta3 integrin globally inhibits several IGF-I-stimulated biologic actions and that synthetic inhibitors are very active in this regard. Because these compounds can be administered to whole animals, they should be very useful in determining whether blocking alphaVbeta3 occupancy in vivo results in alteration in responsiveness to IGF-I.

Animals↗
PubMed2002

Regulation of epithelial cell migration and tumor formation by beta-catenin signaling.

Cell migration requires precise control, which is altered or lost when tumor cells become invasive and metastatic. beta-catenin plays a dual role in this process: as a member of adherens junctions it is essential to link cadherins to the cytoskeleton thereby allowing tight intercellular adhesion, and as a member of the Wnt-signaling pathway, beta-catenin is translocated into the nucleus and serves together with the LEF1/TCF-transcription factors to drive gene expression necessary for the epithelial-to-mesenchymal transition (EMT). Activated beta-catenin signaling has been implicated in the genesis of a variety of tumors. Here we demonstrate a pivotal function for beta-catenin signaling in epithelial cell migration and tumorigenesis. Hepatocyte growth factor (HGF) and epidermal growth factor (EGF) induce beta-catenin signaling under conditions where they stimulate cell motility. Ectopic expression of either stabilized beta-catenin or a regulatable form of activated beta-catenin induces cell migration in different cell types and cooperates with EGF and HGF in this process. Activation of beta-catenin signaling induces expression of the new target gene osteopontin during migration. Cells expressing stabilized beta-catenin also exhibit significantly increased capability to form tumors in a nude mouse xenograft model. The data suggest that a critical threshold of beta-catenin signaling, activated by cooperative mechanisms, may be important during the EMT and tumorigenesis.

Animals↗
PubMed1987

Extracellular matrix and cell migration: locomotory characteristics of MOS-11 cells within a three-dimensional hydrated collagen lattice.

The locomotory trajectories of MOS-11 cells migrating in a three-dimensional hydrated collagen lattice have been determined using a computer-assisted optical sectioning unit. The trajectories have been quantified using a three-dimensional continuous-time Markov probability theory consisting of eight directional states and one stationary state; in the latter the cells are not locomoting. Markov analysis shows that these cells are locomoting in a random manner with regard to direction and remain stationary for about three times as long as they are locomoting. Analysis of persistence also implies random locomotion. Compilation of the distribution of angles between steps reveals that the cells exhibit a predilection for turns around 30 degrees and 150 degrees on either side of the previous step. Time-lapse video recordings show that the cells are bi-polar with ruffling membranes at opposite poles. Ruffling, and hence locomotion, occurs alternately at one pole and then the other, which would account for the distribution of angles encountered. The mean speed of the cells was of the order of 3 microns min-1 including the time stopped and approximately twice this if the time stopped (state 0) is not included. The results obtained provide base-line data on the locomotory characteristics of MOS-11 cells locomoting in a 1.2 mg ml-1 collagen gel. It is now possible to study the role of various matrix components in cell locomotion. Such studies are of importance to embryology, wound healing, host defence mechanisms and the invasion of cancer cells.

Animals↗
PubMed1999

Sphingosine 1-phosphate stimulates cell migration through a G(i)-coupled cell surface receptor. Potential involvement in angiogenesis.

Sphingosine 1-phosphate (SPP) has been shown to inhibit chemotaxis of a variety of cells, in some cases through intracellular actions, while in others through receptor-mediated effects. Surprisingly, we found that low concentrations of SPP (10-100 nM) increased chemotaxis of HEK293 cells overexpressing the G protein-coupled SPP receptor EDG-1. In agreement with previous findings in human breast cancer cells (Wang, F., Nohara, K., Olivera, O., Thompson, E. W., and Spiegel, S. (1999) Exp. Cell Res. 247, 17-28), SPP, at micromolar concentrations, inhibited chemotaxis of both vector- and EDG-1-overexpressing HEK293 cells. Nanomolar concentrations of SPP also induced a marked increase in chemotaxis of human umbilical vein endothelial cells (HUVEC) and bovine aortic endothelial cells (BAEC), which express the SPP receptors EDG-1 and EDG-3, while higher concentrations of SPP were less effective. Treatment with pertussis toxin, which ADP-ribosylates and inactivates G(i)-coupled receptors, blocked SPP-induced chemotaxis. Checkerboard analysis indicated that SPP stimulates both chemotaxis and chemokinesis. Taken together, these data suggest that SPP stimulates cell migration by binding to EDG-1. Similar to SPP, sphinganine 1-phosphate (dihydro-SPP), which also binds to this family of SPP receptors, enhanced chemotaxis; whereas, another structurally related lysophospholipid, lysophosphatidic acid, did not compete with SPP for binding nor did it have significant effects on chemotaxis of endothelial cells. Furthermore, SPP increased proliferation of HUVEC and BAEC in a pertussis toxin-sensitive manner. SPP and dihydro-SPP also stimulated tube formation of BAEC grown on collagen gels (in vitro angiogenesis), and potentiated tube formation induced by basic fibroblast growth factor. Pertussis toxin treatment blocked SPP-, but not bFGF-stimulated in vitro angiogenesis. Our results suggest that SPP may play a role in angiogenesis through binding to endothelial cell G(i)-coupled SPP receptors.

Animals↗
PubMed2004

Corneal development, limbal stem cell function, and corneal epithelial cell migration in the Pax6(+/-) mouse.

PURPOSE: To investigate the etiology of corneal dysfunction in the Pax6(+/-) mouse model of aniridia-related keratopathy. METHODS: Mosaic patterns of X-gal staining were compared in the corneal and limbal epithelia of female Pax6(+/-) and Pax6(+/+) littermates, age 3 to 28 weeks, hemizygous for an X-linked LacZ transgene, and Pax6(+/+), LacZ(-)<-->Pax6(+/+), LacZ(+) and Pax6(+/+), LacZ(-)<-->Pax6(+/-), LacZ(+) chimeras. Histologic examination of chimeric corneas was performed. RESULTS: Disrupted patterns of X-gal staining showed that heterozygosity for Pax6 perturbed clonal patterns of growth and development in the corneal and limbal epithelium. Centripetal migration of Pax6(+/-) corneal epithelial cells was diverted. Normal patterns of centripetal Pax6(+/-) cell migration and epithelial morphology were restored in Pax6(+/+)<-->Pax6(+/-) chimeras. Fewer, larger clones of limbal stem cells were present in Pax6(+/-) eyes, compared with wild-type. In the chimeras, Pax6(+/-) limbal stem cells were cell-autonomously depleted or less efficient than wild-type cells at producing progeny to populate the corneal epithelium. CONCLUSIONS: The correct Pax6 dosage is necessary for normal clonal growth during corneal development, normal limbal stem cell activity, and correct corneal epithelial cell migration. Disruption of normal cell movement in heterozygotes may be the consequence of failure of nonautonomous guidance cues. Degeneration of the corneal surface in aniridia-related keratopathy relates to both a deficiency within the limbal stem cell niche and nonautonomous diversion of corneal epithelial cell migration.

Animals↗
PubMed2002

Embryonic testis cord formation and mesonephric cell migration requires the phosphotidylinositol 3-kinase signaling pathway.

Mesonephric cell migration and seminiferous cord formation are critical processes in embryonic testis development at the time of male sex determination. Extracellular growth factors shown to influence seminiferous cord formation such as neurotropin-3 utilize in part the phosphotidylinositol 3-kinase (PI3K) signal transduction pathway. The current study investigates the hypothesis that the PI3K pathway is critical in seminiferous cord formation and testis development. The role of the PI3K signaling pathway in testicular cord formation was examined using an Embryonic Day 13 organ culture system and a PI3K-specific inhibitor LY294002. The actions of a mitogen-activated protein (MAP) kinase-specific inhibitor PD98059 was also examined. The PI3K inhibitor blocked cord formation or reduced the number of cords in a concentration-dependent manner. The actions of LY294002 were found to have a developmental stage specificity in that cord inhibition was observed in organs from embryos with 16-17 tail somites, while organs from embryos with 19 or more tail somites had no block in cord formation and only a small reduction in cord number. In contrast, the MAP kinase inhibitor PD98059 did not block cord formation and only caused a slight reduction in cord number. Neither PI3K or MAP kinase inhibitor altered apoptotic cell number, suggesting apoptosis was not the reason for the inhibition of cord formation. Embryonic testis cell migration assays showed that the PI3K inhibitor LY294002 blocked mesonephros cell migration into the testis, while the MAP kinase inhibitor had no effect. Observations suggest the interference of cell migration is the cause for the inhibition of cord formation. Western blot analysis confirmed that LY294002 and PD98509 inhibited phosphorylation of Akt and ERK1/ERK2, respectively. Combined observations demonstrate that the PI3K signaling pathway is involved in embryonic testis cord formation and mesonephros cell migration.

Animals↗
PubMed2004

CXCL12 activation of CXCR4 regulates mucosal host defense through stimulation of epithelial cell migration and promotion of intestinal barrier integrity.

Intestinal epithelial cell migration plays a key role in gastrointestinal mucosal barrier formation, enterocyte development, differentiation, turnover, wound healing, and adenocarcinoma metastasis. Chemokines, through engagement of their corresponding receptors, are potent mediators of directed cell migration and are critical in the establishment and regulation of innate and adaptive immune responses. The aim of this study was to define the role for the chemokine CXCL12 and its sole cognate receptor CXCR4 in regulating intestinal epithelial cell migration and to determine its impact on barrier integrity. CXCL12 stimulated the dose-dependent chemotactic migration of human T84 colonic epithelial cells. Epithelial cell migration was inhibited by CXCR4 neutralizing antibody, pertussis toxin, LY-294002, and PD-98059, thereby implicating Galpha(i), phosphatidylinositol 3-kinase (PI3-kinase), and the ERK1/2 MAP kinase pathways in CXCR4-specific signaling. CXCL12 was also shown to increase barrier integrity, as defined by transepithelial resistance and paracellular flux across differentiating T84 monolayers. To determine whether CXCL12 regulated epithelial restitution, we used the normal nontransformed intestinal epithelial cell-6 (IEC-6) wound healing model. By using RT-PCR, immunoblot analysis, and immunofluorescence microscopy, we first showed expression of both CXCR4 and its ligand by IEC-6 cells. We then demonstrated that CXCL12 activated comparable signaling mechanisms to stimulate epithelial migration in the absence of proliferation in wounded IEC-6 monolayers. Taken together, these data indicate that CXCL12 signaling via CXCR4 directs intestinal epithelial cell migration, barrier maturation, and restitution, consistent with an important mechanistic role for these molecules in mucosal barrier integrity and innate host defense.

Animals↗
PubMed2001

Screening of natural compounds for inhibitory activity on colon cancer cell migration.

We examined the effects of 75 kinds of natural compounds, such as alkaloids, phenylpropanoids, flavonoids, steroids and terpenoids on the in vitro migration and proliferation of colon 26-L5 cells, in comparison with anti-cancer drugs used for chemotherapy. Twenty-three of the 75 compounds inhibited markedly tumor cell migration. Among the 23 compounds, evodiamine showed the most potent and selective inhibitory activity on tumor cell migration with an IC50 value of 1.25 microg/ml, which was about 20 times lower than that for tumor cell proliferation. The migratory inhibition reached about 70% at 10 microg/ml of evodiamine. On the other hand, most of anti-cancer drugs tested, except for paclitaxel, had little effect on tumor cell migration at the concentrations strongly inhibiting tumor cell proliferation. Paclitaxel suppressed tumor cell migration in a concentration-dependent manner and achieved about 70% inhibition at 10 microg/ml with a marginal effect on cell proliferation. These results suggest that evodiamine and paclitaxel may be regarded as leading compounds for anti-metastatic agents acting through the inhibition of tumor cell migration without cytotoxicity.

Animals↗
PubMed1987

In vitro bone marrow cell migration to supernatants prepared from thymic epithelial cell cultures.

Thymic epithelial cell cultures were established from neonatal CBA/J mice by inhibition of fibroblast overgrowth. Epithelial cells were identified by their cobblestone appearance in culture, by the presence of keratin, and by ultrastructural analysis demonstrating desmosomes. Supernatants were prepared by incubation of confluent cultures of these cells in serum-free media. Using blind well chambers, these supernatants were chemoattractive to murine bone marrow cells, enriched for immature lymphoid cells, and decreased the myeloid to lymphoid ratio in the migrating cell population. Interleukin 2 had no effect as a modulator of this chemoattraction, nor did it possess chemoattractive properties. Supernatants prepared from epidermal growth factor stimulated thymic epithelial cells possessed significantly enhanced chemoattractive properties to bone marrow cells, and was found to be a thymic epithelial cell mitogen. Supernatants from serum-free cultures of thymocytes also induced a significant migration of bone marrow cells but were found to enrich for mature myeloid cells.

Animals↗
PubMed2006

Expression of Wnt-5a is correlated with aggressiveness of gastric cancer by stimulating cell migration and invasion.

Wnt-5a is a representative ligand that activates a beta-catenin-independent pathway in the Wnt signaling. Although abnormal activation of beta-catenin-dependent pathway is often observed in human cancer, the relationship between beta-catenin-independent pathway and tumorigenesis is not clear. We sought to clarify how Wnt-5a is involved in aggressiveness of gastric cancer. Abnormal expression of Wnt-5a was observed in 71 of 237 gastric cancer cases by means of immunohistochemistry. The positivity of Wnt-5a expression was correlated with advanced stages and poor prognosis of gastric cancer. Wnt-5a had the abilities to stimulate cell migration and invasion in gastric cancer cells. Wnt-5a activated focal adhesion kinase and small GTP-binding protein Rac, both of which are known to play a role in cell migration. Cell migration, membrane ruffling, and turnover of paxillin were suppressed in Wnt-5a knockdown cells. Furthermore, anti-Wnt-5a antibody suppressed gastric cancer cell migration. These results suggest that Wnt-5a stimulates cell migration by regulating focal adhesion complexes and that Wnt-5a is not only a prognostic factor but also a good therapeutic target for gastric cancer.

Cell Movement↗
PubMed2006

Functional KCa3.1 K+ channels are required for human lung mast cell migration.

BACKGROUND: Mast cell recruitment and activation are critical for the initiation and progression of inflammation and fibrosis. Mast cells infiltrate specific structures in many diseased tissues such as the airway smooth muscle (ASM) in asthma. This microlocalisation of mast cells is likely to be key to disease pathogenesis. Human lung mast cells (HLMC) express the Ca2+ activated K+ channel K(Ca)3.1 which modulates mediator release, and is proposed to facilitate the retraction of the cell body during migration of several cell types. A study was undertaken to test the hypothesis that blockade of K(Ca)3.1 would attenuate HLMC proliferation and migration. METHODS: HLMC were isolated and purified from lung material resected for bronchial carcinoma. HLMC proliferation was assessed by cell counts at various time points following drug exposure. HLMC chemotaxis was assayed using standard Transwell chambers (8 microm pore size). Ion currents were measured using the single cell patch clamp technique. RESULTS: K(Ca)3.1 blockade with triarylmethane-34 (TRAM-34) did not inhibit HLMC proliferation and clotrimazole had cytotoxic effects. In contrast, HLMC migration towards the chemokine CXCL10, the chemoattractant stem cell factor, and the supernatants from tumour necrosis factor alpha stimulated asthmatic ASM was markedly inhibited with both the non-selective K(Ca)3.1 blocker charybdotoxin and the highly specific K(Ca)3.1 blocker TRAM-34 in a dose dependent manner. Although K(Ca)3.1 blockade inhibits HLMC migration, K(Ca)3.1 is not opened by the chemotactic stimulus, suggesting that it must be involved downstream of the initial receptor-ligand interactions. CONCLUSIONS: Since modulation of K(Ca)3.1 can inhibit HLMC chemotaxis to diverse chemoattractants, the use of K(Ca)3.1 blockers such as TRAM-34 could provide new therapeutic strategies for mast cell mediated diseases such as asthma.

Asthma↗
PubMed1997

Antisense inhibition of beta-actin mRNA localization and its effect on smooth muscle cell migration.

A crucial step in cell migration involves changes in the actin cytoskeleton in response to extracellular signals. We have previously shown that beta-actin transcripts are associated with mobile regions of mouse 3T3 fibroblasts when grown in the presence of serum. In the current study we used in situ hybridization and laser scanning confocal microscopy to show that cultured rat smooth muscle cells also localize beta-actin mRNA to the cell periphery and that this peripheral pool of beta-actin mRNA is dependent on the presence of growth factors in the culture medium. We also show that antisense phosphorothioated oligonucleotides directed against sequences in the 3' untranslated region of rat beta-actin mRNA block peripheral localization of beta-actin mRNA while the corresponding control oligonucleotides have no effect. Time-lapse video analysis demonstrates that the antisense oligonucleotides inhibit rat smooth muscle cell migration in culture and analysis of beta-actin mRNA confirms this is not due to changes in beta-actin gene expression or instability of the message. Our results suggest that depletion of beta-actin transcripts from the cell periphery is associated with suppression of SMC migration.

Actins↗
PubMed2005

Blocking tumor cell migration and invasion with biphenyl isoxazole derivative KRIBB3, a synthetic molecule that inhibits Hsp27 phosphorylation.

Cell migration is a prerequisite for cancer invasion and metastasis, suggesting cell motility as a potential therapeutic target for cancer treatment. A synthetic library was screened to identify inhibitors of tumor cell migration. From this, we discovered that CAC-1098 (aurintricarboxylic acid) and CBI-0997 (5-(2,4-dimethoxy-5-ethylphenyl)-4-(4-bromophenyl) isoxazole) inhibited migration of MDA-MB-231 cells with IC50 = 5 and 50 nM, respectively. We synthesized KRIBB3 (5-(5-ethyl-2-hydroxy-4-methoxyphenyl)-4-(4-methoxyphenyl) isoxazole) by replacing the bromide group of CBI-0997 with a methoxyl group. Like CBI-0997, KRIBB3 has anti-migratory and anti-invasive activities in MDA-MB-231 cells. Because KRIBB3 has a better drug-like structure, we focused our effort on further understanding its anti-migratory mechanism. Biotinyl-KRIBB3 was synthesized as an affinity probe for identification of KRIBB3-binding proteins. Using affinity chromatography, we identified Hsp27 as a target protein of KRIBB3 in vitro. Treatment of MDA-MB-231 cells with phorbol 12-myristate 13-acetate induced protein kinase C-dependent phosphorylation of Hsp27 and tumor cell migration. In contrast, treatment of MDA-MB-231 cells with KRIBB3 blocked phorbol 12-myristate 13-acetate-induced phosphorylation of Hsp27 and tumor cell migration. Furthermore, overexpression of Hsp27 antagonized the inhibitory effect of KRIBB3 on tumor cell invasion, and knockdown of Hsp27 using small interfering RNA inhibited tumor cell migration. Overall, our results demonstrate that KRIBB3 inhibits tumor cell migration and invasion by blocking protein kinase C-dependent phosphorylation of Hsp27 through its direct binding to Hsp27.

Amino Acid Sequence↗