The process of macropinocytosis is an essential aspect normal cell function, contributing to both growth and motile processes cells. p21-activated kinases (PAKs) are targets for activated Rac Cdc42 guanosine 5'-triphosphatases have been shown regulate the actin-myosin cytoskeleton. In fibroblasts PAK1 localizes areas membrane ruffling, as well amiloride-sensitive pinocytic vesicles. Expression a kinase autoinhibitory domain blocked platelet-derived factor- RacQ61L-stimulated uptake 70-kDa...

The mechanisms through which the small GTPases Rac1 and Cdc42 regulate formation of membrane ruffles, lamellipodia, filopodia are currently unknown. p21-activated kinases (PAKs) direct targets active Rac can induce assembly polarized cytoskeletal structures when expressed in fibroblasts, suggesting that they may play a role mediating effects these on dynamics. We have examined subcellular localization endogenous PAK1 fibroblast cell lines using specific antibodies. is detected submembranous...

The Rho GTPase Rac regulates actin cytoskeleton reorganization to form cell surface extensions (lamellipodia) required for migration/invasion during cancer metastasis. hyperactivation and overexpression are associated with aggressive cancers; thus, interference of the interaction its direct upstream activators, guanine nucleotide exchange factors (GEFs), is a viable strategy inhibiting activity. We synthesized EHop-016, novel inhibitor activity, based on structure established Rac/Rac GEF...

We previously reported that dietary genistein inhibits mammary tumor growth and metastasis of the highly metastatic MDA-MB-435 cancer cells in immunocompromised mice. The purpose herein was to characterize role novel oncogenic microRNA (miRNA) miR-155 anticancer effects breast cancer. effect determined on cell viability, apoptosis, expression its targets. At low physiologically relevant concentrations, viability induces apoptosis Hs578t cells, without affecting nonmetastatic MCF-7 cells. In...

The Akt/adenosine monophosphate protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway has emerged as a critical signaling nexus for regulating cellular metabolism, energy homeostasis, and cell growth. Thus, dysregulation this contributes to the development metabolic disorders such obesity, type 2diabetes, cancer. We previously reported that combination grape polyphenols (resveratrol, quercetin catechin: RQC), at equimolar concentrations, reduces breast cancer (BC) growth...

The Rho GTPases Rac (Ras-related C3 botulinum toxin substrate) and Cdc42 (cell division control protein 42 homolog) regulate cell functions governing cancer malignancy, including polarity, migration, cell-cycle progression. Accordingly, our recently developed inhibitor EHop-016 (IC50, 1,100 nmol/L) inhibits migration viability reduces tumor growth, metastasis, angiogenesis in vivo Herein, we describe MBQ-167, which with IC50 values of 103 78 nmol/L, respectively, metastatic breast cells....

Metastatic disease still lacks effective treatments, and remains the primary cause of cancer mortality. Therefore, there is a critical need to develop better strategies inhibit metastatic cancer. The Rho family GTPase Rac an ideal target for anti-metastatic therapy, because key molecular switch that activated by myriad cell surface receptors promote migration/invasion survival. Previously, we reported design development EHop-016, small molecule compound, which inhibits activity cells with...

A monomeric actin bundling protein with a native molecular weight of approximately 50,000 (ABP-50) has been isolated from amoebae Dictyostelium discoideum. ABP-50 cross-links F-actin to form tightly packed bundles, some which are highly ordered. It exhibits Kd 2.1 microM and molar ratio 1:1 in bundles. Calcium ATP at physiological concentrations have no effect on these activities. is immunologically unrelated 30-kDa protein, previously described Dictyostelium. Immunofluorescence...

Abstract Leukocyte chemoattractants are known to stimulate signaling pathways that involve Rho family GTPases. Direct evidence for the regulation of leukocyte cytoskeleton by GTPases and their effector targets is limited. The p21-activated kinases (PAKs) specific activated GTP-bound Rac Cdc42, have been proposed as regulators chemoattractant-driven actin cytoskeletal changes in fibroblasts. PAK1 co-localizes with F-actin cortical structures stimulated fibroblasts, mutants induce membrane...

To investigate the effects soy isoflavones in established cancers, role of genistein, daidzein, and combined was studied on progression subcutaneous tumors nude mice created from green fluorescent protein (GFP) tagged-MDA-MB-435 cells. Following tumor establishment, were gavaged with vehicle or genistein daidzein at 10 mg/kg body weight (BW) a combination (10 BW), (9 glycitein (1 BW) three times per week. Tumor quantified by whole fluorescence image analysis followed microscopic excised...

Abstract The small G-protein Rac1 is a central player in cancer progression and metastatic dissemination. has been established as bona fide effector of receptor tyrosine kinases, acting signaling node for motility, invasiveness, mitogenesis, gene expression. Previous studies demonstrated that hyperactivated aggressive cellular models prostate cancer. Here, we show CRISPR/Cas9-based knockout leads to impaired cell proliferation migration. Rac1-null cells display profound alterations...

Abstract In this work we evaluate the cartical expansion model for amoeboid chemo‐taxis with regard to new information about molecular events in cytoskeleton following chemo‐tactic stimulation of Dictyostelium amoebae. A rapid upshift concentration chemoattrac‐tant can be used synchronize motile behavior a large population cells. This synchrony presents an opportunity study biochemical basis morphological changes such as pseudopod extension that are required chemotaxis. Changes composition...

Abstract ABP‐50 is the elongation factor‐1 alpha (EF‐1 alpha) of Dictyostelium discoideum (Yang et al.: Nature 347:494–496, 1990). also an actin filament binding and bundling protein (Demma J. Biol. Chem . 265:2286–2291, In present study we have investigated compartmentalization in both resting stimulated cells. Immunofluorescence microscopy shows that addition to being colocalized with F‐actin surface extensions unstimulated cells, exhibits a diffuse distribution throughout cytosol. Upon...

Actin polymerization occurs in amebae of Dictyostelium discoideum after chemotactic stimulation (Hall, A. L., Schlein, and J. Condeelis. 1988. Cell. Biochem. 37:285-299). When cells are lysed with Triton X-100 during stimulation, an actin nucleation activity is detected lysates by measuring the rate pyrene-labeled polymerization. This stimulated closely correlated observed vivo its kinetics, developmental regulation, cytochalasin D sensitivity. coordinate pseudopod extension synchronized...

Triton-insoluble cytoskeletons were isolated from Dictyostelium discoideum AX3 cells prior to and following stimulation with 2'deoxy cyclic adenosine monophosphate (cAMP). Temporal changes in the content of actin a 120,000 dalton actin-binding protein (ABP-120) monitored. Both ABP-120 incorporated into cytoskeleton at 30-40 seconds stimulation, which is cotemporal onset pseudopod extension during amoebae chemoattractants. Changes total cytoskeletal myosin determined under same experimental...

Resveratrol, a polyphenol from grapes and red wine has many health beneficial effects, including protection against cardiovascular neurodegenerative diseases cancer. However, our group others have provided evidence for dual cancer promoting or inhibitory role resveratrol in breast cancer, dependent on estrogenic antiestrogenic activities. Moreover, much of the effects been reported studies with high non-physiological concentrations.We investigated range concentrations (0.5, 5, 50 mg/kg body...

An acquired somatic mutation at codon 816 in the KIT receptor tyrosine kinase is associated with poor prognosis patients systemic mastocytosis and acute myeloid leukemia (AML). Treatment of leukemic cells bearing this an allosteric inhibitor p21-activated (Pak) or its genetic inactivation results growth repression due to enhanced apoptosis. Inhibition upstream effector Rac abrogates oncogene-induced activity Pak. Although both Rac1 Rac2 are constitutively activated via guanine nucleotide...

Triple-negative breast cancer (TNBC) is an aggressive form of cancer, with a high predisposition for locally invasive and metastatic cancer. With the objective to reduce metastasis, we developed small molecule inhibitors target drivers Rho GTPases Rac Cdc42. Of these, MBQ-167 inhibits both Cdc42 IC50s 103 78 nmol/L, respectively; consequently, p21-activated kinase (PAK) signaling, cell proliferation, migration, mammosphere growth; induces cell-cycle arrest apoptosis; decreases HER2-type...