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1.
Sci Rep ; 7: 40070, 2017 01 10.
Article in English | MEDLINE | ID: mdl-28071670

ABSTRACT

Functional reactivation of p53 pathway, although arduous, can potentially provide a broad-based strategy for cancer therapy owing to frequent p53 inactivation in human cancer. Using a phosphoprotein-screening array, we found that Benzyl Isothiocynate, (BITC) increases p53 phosphorylation in breast cancer cells and reveal an important role of ERK and PRAS40/MDM2 in BITC-mediated p53 activation. We show that BITC rescues and activates p53-signaling network and inhibits growth of p53-mutant cells. Mechanistically, BITC induces p73 expression in p53-mutant cells, disrupts the interaction of p73 and mutant-p53, thereby releasing p73 from sequestration and allowing it to be transcriptionally active. Furthermore, BITC-induced p53 and p73 axes converge on tumor-suppressor LKB1 which is transcriptionally upregulated by p53 and p73 in p53-wild-type and p53-mutant cells respectively; and in a feed-forward mechanism, LKB1 tethers with p53 and p73 to get recruited to p53-responsive promoters. Analyses of BITC-treated xenografts using LKB1-null cells corroborate in vitro mechanistic findings and establish LKB1 as the key node whereby BITC potentiates as well as rescues p53-pathway in p53-wild-type as well as p53-mutant cells. These data provide first in vitro and in vivo evidence of the integral role of previously unrecognized crosstalk between BITC, p53/LKB1 and p73/LKB1 axes in breast tumor growth-inhibition.


Subject(s)
Antineoplastic Agents/metabolism , Breast Neoplasms/pathology , Isothiocyanates/metabolism , Protein Serine-Threonine Kinases/metabolism , Signal Transduction/drug effects , Tumor Protein p73/metabolism , Tumor Suppressor Protein p53/metabolism , AMP-Activated Protein Kinase Kinases , Cell Line, Tumor , Humans , Phosphoproteins/analysis , Phosphorylation , Protein Processing, Post-Translational , Proteome/analysis
2.
J Biol Chem ; 288(4): 2179-89, 2013 Jan 25.
Article in English | MEDLINE | ID: mdl-23235160

ABSTRACT

Cell-cell adhesions and the cytoskeletons play important and coordinated roles in cell biology, including cell differentiation, development, and migration. Adhesion and cytoskeletal dynamics are regulated by Rho-GTPases. ARHGAP21 is a negative regulator of Rho-GTPases, particularly Cdc42. Here we assess the function of ARHGAP21 in cell-cell adhesion, cell migration, and scattering. We find that ARHGAP21 is localized in the nucleus, cytoplasm, or perinuclear region but is transiently redistributed to cell-cell junctions 4 h after initiation of cell-cell adhesion. ARHGAP21 interacts with Cdc42, and decreased Cdc42 activity coincides with the appearance of ARHGAP21 at the cell-cell junctions. Cells lacking ARHGAP21 expression show weaker cell-cell adhesions, increased cell migration, and a diminished ability to undergo hepatocyte growth factor-induced epithelial-mesenchymal transition (EMT). In addition, ARHGAP21 interacts with α-tubulin, and it is essential for α-tubulin acetylation in EMT. Our findings indicate that ARHGAP21 is a Rho-GAP involved in cell-cell junction remodeling and that ARHGAP21 affects migration and EMT through α-tubulin interaction and acetylation.


Subject(s)
Epithelial-Mesenchymal Transition , Epithelium/metabolism , GTPase-Activating Proteins/physiology , Tubulin/metabolism , Acetylation , Animals , Cell Adhesion , Cell Communication , Cell Line, Tumor , Cell Movement , Dogs , GTPase-Activating Proteins/metabolism , Humans , Madin Darby Canine Kidney Cells , Neoplasm Metastasis , RNA Interference , Time Factors , cdc42 GTP-Binding Protein/metabolism
3.
J Cell Sci ; 125(Pt 17): 4001-13, 2012 Sep 01.
Article in English | MEDLINE | ID: mdl-22685327

ABSTRACT

Hepatocyte growth factor (HGF) signaling drives epithelial cells to scatter by breaking cell-cell adhesions and causing them to migrate as solitary cells, a process that parallels epithelial-mesenchymal transition. HGF binds and activates the c-met receptor tyrosine kinase, but downstream signaling required for scattering remains poorly defined. We have applied a chemical biology approach to identify components of HGF signaling that are required for scattering in an in vitro model system. This approach yields a number of small molecules that block HGF-induced scattering, including a calcium channel blocker. We show that HGF stimulation results in sudden and transient increases in ion channel influxes at the plasma membrane. Although multiple channels occur in the membranes of our model system, we find that TrpC6 is specifically required for HGF-induced scattering. We further demonstrate that HGF-induced ion influxes through TrpC6 channels coincide with a transient increase in nuclear factor of activated T-cells (NFAT)-dependent gene transcription and that NFAT-dependent gene transcription is required for HGF-induced cell scattering.


Subject(s)
Cell Membrane/metabolism , Epithelial Cells/cytology , Epithelial Cells/metabolism , Ions/metabolism , NFATC Transcription Factors/metabolism , Proto-Oncogene Proteins c-met/metabolism , Transcription, Genetic , Actins/metabolism , Animals , Calcium/metabolism , Cell Membrane/drug effects , Dogs , Epithelial Cells/drug effects , Epithelial-Mesenchymal Transition/drug effects , Hepatocyte Growth Factor/pharmacology , Madin Darby Canine Kidney Cells , Microtubules/drug effects , Microtubules/metabolism , Reproducibility of Results , Signal Transduction/drug effects , Small Molecule Libraries/chemistry , Small Molecule Libraries/pharmacology , TRPC Cation Channels/metabolism , TRPV Cation Channels/metabolism , Transcription, Genetic/drug effects
4.
J Neurosurg ; 111(6): 1175-8, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19558302

ABSTRACT

OBJECT: In this prospective randomized clinical trial, investigators looked at wound healing after craniotomy. The hypothesis was that the self-closing plastic scalp clips used for hemostasis on the skin edge might lead to localized microscopic tissue damage and subsequent delayed wound healing. METHODS: The trial consisted of 2 arms in which different methods were used to secure scalp hemostasis: 1) the routinely used plastic clips (Scalpfix, Aesculap); and 2) the older method of artery forceps placed on the galea. Participants were restricted to those > 16 years of age undergoing craniotomies expected to last > 2 hours. Repeat operations were not included. One hundred fifty patients were enrolled. They were visited at 3 and 6 weeks postoperatively by an observer blinded to the method used, and the wounds were assessed for macroscopic epithelial closure, signs of infection, and hair regrowth by using a predefined assessment scale. RESULTS: The results showed no significant difference in wound healing between the 2 groups at either 3 weeks (OR 0.55, 95% CI 0.27-1.11; p = 0.09) or 6 weeks (OR 0.79, 95% CI 0.39-1.58; p = 0.50). The length of operation was found to be a significant factor affecting wound healing at 6 weeks (OR/hour 0.68, 95% CI 0.51-0.92; p = 0.01). CONCLUSIONS: The use of Aesculap Scalpfix self-retaining plastic scalp clips on the skin edge during craniotomy surgery does not appear to affect wound healing significantly to the postoperative 6-week mark.


Subject(s)
Craniotomy , Hemostasis, Surgical/instrumentation , Scalp/injuries , Surgical Instruments/adverse effects , Wound Healing , Craniotomy/adverse effects , Craniotomy/instrumentation , Follow-Up Studies , Hemostasis, Surgical/adverse effects , Humans , Odds Ratio , Plastics , Prospective Studies , Severity of Illness Index , Time Factors , Treatment Outcome
5.
J Neurosurg ; 103(1): 176-8, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16121989

ABSTRACT

In this report the authors describe a patient in whom a symptomatic carotid-cavernous fistula developed 8 months after percutaneous balloon compression of the trigeminal ganglion. The fistula involved a branch of the external carotid artery and was cured with microcatheter embolization.


Subject(s)
Arteriovenous Fistula/etiology , Catheterization/adverse effects , Cavernous Sinus/pathology , Meningeal Arteries/pathology , Trigeminal Ganglion , Aged , Arteriovenous Fistula/diagnostic imaging , Arteriovenous Fistula/pathology , Cavernous Sinus/diagnostic imaging , Female , Humans , Meningeal Arteries/diagnostic imaging , Radiography , Trigeminal Neuralgia/therapy
6.
Child Dev ; 68(6): 1105-1116, 1997 Dec.
Article in English | MEDLINE | ID: mdl-29106734

ABSTRACT

Unlike previous studies of the development of reasoning about moral dilemmas, the 2 studies reported separated judicial reasoning (the application of rules) from legislative reasoning (the justification of rules), as well as attending to other aspects of context, using a modification of the weakly interpretive scoring method of Langford and D'Cruz. This assigns justifications to relatively simple conceptually defined categories. Findings were in accord with substantially modified versions of the views of Piaget and Kohlberg, according to which legislative reasoning can be divided into 3 main types of stages in the period 7-21 years: heteronomy (Piaget) or egocentrism (Kohlberg); local groups (attention to group interests, harmony, and reciprocity in local groups), wider groups (attention to these thing in wider groups). Findings contradicted Gibbs's theory.

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