Role In Cancer Cell Migration Research Articles

Glioblastoma U-87 cell electrotaxis is hindered by doxycycline with a concomitant reduction in the matrix metallopeptidase-9 expression

Electric fields (EF) play an essential role in cancer cell migration. Numerous cancer cell types exhibit electrotaxis under direct current electric fields (dcEF) of physiological electric field strength (EFs). This study investigated the effects of doxycycline on the electrotactic responses of U87 cells. After EF stimulation, U87 cells migrated toward the cathode, whereas doxycycline-treated U87 cells exhibited enhanced cell mobility but hindered cathodal migration. We further investigated the expression of the metastasis-correlated proteins matrix metallopeptidase-2 (MMP-2) and MMP-9 in U87 cells. The levels of MMP-2 in the cells were not altered under EF or doxycycline stimulation. In contrast, the EF stimulation greatly enhanced the levels of MMP-9 and then repressed in doxycycline-cotreated cells, accompanied by reduced cathodal migration. Our results demonstrated that an antibiotic at a non-toxic concentration could suppress the enhanced cell migration accelerated by EF of physiological strength. This finding may be applied as an anti-metastatic treatment for cancers.

MLL1 regulates cytokine-driven cell migration and metastasis.

Cell migration is a critical contributor to metastasis. Cytokine production and its role in cancer cell migration have been traditionally associated with immune cells. We find that the histone methyltransferase Mixed-Lineage Leukemia 1 (MLL1) controls 3D cell migration via cytokines, IL-6, IL-8, and TGF-β1, secreted by the cancer cells themselves. MLL1, with its scaffold protein Menin, controls actin filament assembly via the IL-6/8/pSTAT3/Arp3 axis and myosin contractility via the TGF-β1/Gli2/ROCK1/2/pMLC2 axis, which together regulate dynamic protrusion generation and 3D cell migration. MLL1 also regulates cell proliferation via mitosis-based and cell cycle-related pathways. Mice bearing orthotopic MLL1-depleted tumors exhibit decreased lung metastatic burden and longer survival. MLL1 depletion leads to lower metastatic burden even when controlling for the difference in primary tumor growth rates. Combining MLL1-Menin inhibitor with paclitaxel abrogates tumor growth and metastasis, including preexistent metastasis. These results establish MLL1 as a potent regulator of cell migration and highlight the potential of targeting MLL1 in patients with metastatic disease.

Dietary Polyphenols Effects on Focal Adhesion Plaques and Metalloproteinases in Cancer Invasiveness.

Focal adhesion plaques (FAPs) play an important role in the communication between cells and the extracellular matrix (ECM) and in cells' migration. FAPs are macromolecular complexes made by different proteins which also interact with matrix metalloproteinases (MMPs). Because of these fundamental properties, FAPs and MMPs are also involved in cancer cells' invasion and in the metastatic cascade. The most important proteins involved in FAP formation and activity are (i) integrins, (ii) a complex of intracellular proteins and (iii) cytoskeleton proteins. The latter, together with MMPs, are involved in the formation of filopodia and invadopodia needed for cell movement and ECM degradation. Due to their key role in cancer cell migration and invasion, MMPs and components of FAPs are often upregulated in cancer and are thus potential targets for cancer therapy. Polyphenols, a large group of organic compounds found in plant-based food and beverages, are reported to have many beneficial healthy effects, including anticancer and anti-inflammatory effects. In this review, we discuss the growing evidence which demonstrates that polyphenols can interact with the different components of FAPs and MMPs, inhibit various pathways like PI3K/Akt, lower focal adhesion kinase (FAK) phosphorylation and decrease cancer cells' invasiveness, leading to an overall antitumoral effect. Finally, here we highlight that polyphenols could hold potential as adjunctive therapies to conventional cancer treatments due to their ability to target key mechanisms involved in cancer progression.

Investigating the Effects of HMGB1 Overexpression on Colorectal Cancer Cell Migration via Oncolytic Herpes simplex Virus Type 1 (oHSV-1).

Colorectal Cancer (CRC) represents a significant global health challenge, and its progression, resistance to therapy, and metastasis are strongly influenced by the tumor microenvironment, including factors like hypoxia. This study explores the impact of High Mobility Group Box 1 (HMGB1) overexpression on CRC cell migration, while identifying potential genes associated with this process. To explore this, we developed oncolytic virotherapy, resulting in HSVHMGB1, an oncolytic Herpes simplex virus that expresses HMGB1. HMGB1 is known its role in cancer progression, particularly in the context of cancer cell migration. Contrary to expectations, our scratch assays indicated that HSV-HMGB1 did not significantly induce migration in CRC cells, suggesting that HMGB1 might not directly contribute to this process. Employing microarray analysis, we investigated gene expression changes linked to CRC cell migration, leading to construction of a Protein-Protein Interaction (PPI) network. This network revealed the presence of hub proteins, including as NDRG1, LGALS1, and ANGPTL4, which are recognized for their roles in cancer cell migration. The differential expression of these genes under hypoxic conditions was further validated using quantitative RT-PCR, aligning with the findings from our microarray data. Our findings emphasize the complex regulation of CRC cell migration, and provides valuable insights into potential molecular mechanisms and pathways. These findings have implications for further research into cancer progression and the development of therapeutic strategies.

CAMSAP2 enhances lung cancer cell metastasis by mediating RASAL2 degradation

AimsCancer metastasis significantly contributes to mortality in lung cancer patients. Calmodulin-regulated spectrin-associated protein family member 2 (CAMSAP2) plays a significant role in cancer cell migration; however, its role in lung cancer metastasis and the underlying mechanism remain largely unknown. The present study aimed to investigate the impact of CAMSAP2 on lung cancer. Main methodsThe clinical relevance of CAMSAP2 in lung cancer patients was assessed using public database. RNA interference experiments were conducted to investigate role of CAMSAP2 in cell migration through transwell and wound healing assays. Molecular mechanisms were explored by identifying the possible interacting partners and pathways using the BioGRID and KEGG pathway analyses. The impact of CAMSAP2 on Ras protein activator-like 2 (RASAL2)-mediated lung cancer metastasis was investigated through biochemical assays. Additionally, in vivo experimentation using a murine tail vein metastasis model was performed to comprehend CAMSAP2's influence on metastasis. Key findingsA high expression level of CAMSAP2 was associated with poor overall survival in lung cancer patients and it positively correlated with cell migration in non-small cell lung cancer (NSCLC) cell lines. Knockdown of CAMSAP2 inhibited lung cancer cell motility in vitro and metastasis in vivo. Proteomic and biochemical analyses revealed the interaction between CAMSAP2 and RASAL2, which facilitates the degradation of RASAL2 through the ubiquitin–proteasome system. These degradation processes resulted in the activation of the extracellular signal-regulated kinase (ERK) signaling pathway, thereby promoting lung cancer metastasis. Collectively, the results of this study suggest that CAMSAP2 is a crucial regulator of cancer cell migration and metastasis and a promising therapeutic target for lung cancer.

MACC1 and MET as markers associated with progression and metastasis in cutaneous melanoma.

Cutaneous melanoma is the most common lethal malignancy among skin cancers and has a high propensity for metastasis. Understanding the mechanisms governing tumorigenesis, progression and metastasis as well as identifying biomarkers guiding risk stratification and management of the disease is essential. MACC1 has been found to play key roles in cancer cell migration, invasion, epithelial-to-mesenchymal transition, and metastasis in various types of cancer, through activation of MET signaling. In this study, we examined the extent of MACC1 and MET protein expression by immunohistochemical staining in a tissue microarray constructed from twenty-three melanomas and ten melanocytic nevi. We observed significantly higher levels of MACC1 expression on average in metastatic melanomas, comparing to primary melanomas and nevi. MET expression in metastatic melanomas was also significantly higher than in nevi. MACC1 expression does not appear to correlate with MET expression in nevi and primary melanomas. However, this correlation appears stronger in metastatic melanomas, where seven (78%) of nine cases show intermediate to high expression of both MACC1 and MET. The expressions of MACC1 and MET do not show significant differences based on other clinicopathologic factors including patient age, gender, histologic subtypes, depth of invasion, and staging. Our study suggests that high expression of MACC1 or both MACC1 and MET is associated with metastasis of cutaneous melanoma.

Abstract 2184: Short Peptides derived from MIEN1 and their analogs exhibit anti-cancer activity in breast and prostate cancer cells

Abstract Migration and invasion enhancer 1 (MIEN1) is overexpressed in various cancers and plays an important role in cancer cell migration and invasion. Conserved regions of ITAM and prenylation motif in MIEN1 were used as a template to identify anti-cancer peptides. RNA-seq, qPCR analysis and western blots showed changes in the transcriptome and protein expression after peptide treatment. The two bioactive peptides inhibited genes and proteins responsible for cancer cell migration and invasion in both MDA-MB-231 breast cancer and DU-145 prostate cancer cells. The mechanism of the action of the peptides involves the inhibition of key pathways like Epithelial-Mesenchymal transition and Epidermal Growth Factor-mediated NF-κB pathway to exert their anti-cancer activity. Interestingly, the peptides targeted the same signal transduction pathways followed by parental MIEN1 to show its cancer properties. Thus, the two peptides acted as dominant negative effectors of MIEN1 activity. Additionally, Peptide-treatments induced apoptosis in mice groups bearing tumors derived from MDA-MB-231 cells as evidenced by increased levels of cleaved caspase-3 and PARP proteins in western blots. Interestingly, the MIEN1 mRNA and protein expression was lowered in the in vivo breast cancer tumor models which remained unchanged in MDA-MB-231 breast cancer cells indicating an improved therapeutic activity in living system. The peptides did not cause any toxicity in the mice group which received peptides only, at three times the dose used during in vivo assays. Citation Format: AMIT Kumar Tripathi, Jamboor K. Vishwanatha. Short Peptides derived from MIEN1 and their analogs exhibit anti-cancer activity in breast and prostate cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2184.

The role of p21-activated kinase 4 in the progression of oral squamous cell carcinoma by targeting PI3K-AKT signaling pathway.

Oral squamous carcinoma (OSCC), the most common head and neck malignancy, has a strong propensity for malignant proliferation and metastasis, which will decrease the survival of patients. P21-activated kinase 4 (PAK4), a classical serine/threonine protein kinase with multiple cellular functions, has an essential role in cancer cell migration and invasion. Here, we elucidated the function and possible molecular mechanisms of the effect of PAK4 on the biological behaviors of OSCC. The expression of genes and protein was detected by real-time PCR and western blotting. We used oral squamous carcinoma cell lines, Tca8117, Cal 27, SCC 4, and SCC 9 for validation of our cell function data. Flow cytometry, 3D cultures, and clone formation assay were used to detect proliferation of cells. RNA sequencing and bioinformatic analysis was performed to determine the potential function of PAK4. Immunohistochemistry, western blotting and real-time PCR demonstrated that PAK4 expression was up-regulated in OSCC tissues. Overexpression of PAK4 promoted the proliferation, migration and invasion of OSCC cell lines. RNA sequencing (RNA-seq) for the transcriptome-wide analysis of differential gene expression followed by bioinformatic analysis was performed to determine the potential function of PAK4. Based on the KEGG enrichment analysis and GO analysis of differential expression genes (DEGs) we found that PAK4 promotes the cell-cycle machinery, which associated with 44 regulated genes, thereby promoting cancer cell differentiation. This study demonstrates that the PAK4 regulates the biological behaviors of OSCC by PI3K-AKT signaling pathway, and these findings might provide a novel strategy for OSCC treatment.

FOSL1 promotes tumor growth and invasion in ameloblastoma.

BackgroundFOSL1, a key component of the Activating protein-1 (AP-1) transcriptional complex, plays an important role in cancer cell migration, invasion, and proliferation. However, the impact of FOSL1 in ameloblastoma (AM) has not been clarified. Herein, we aimed to assess the expression of FOSL1 and investigate its functional role in AM.MethodsThe expression of FOSL1 was examined based on an immunohistochemistry analysis of 96 AM samples. Cell proliferation, migration, invasion, and tumorigenesis were assessed using Cell Counting Kit-8 (CCK-8), colony formation, Transwell, and sphere formation assays. RNA sequencing (RNA-seq) was employed to investigate the molecular alterations of AM cells upon FOSL depletion. Microarrays of AMs were downloaded from the Gene Expression Omnibus (GEO) database for bioinformatics analysis. In addition, patient-derived AM organoids were used to evaluate the therapeutic value of the AP-1 inhibitor.ResultsFOSL1 was detected in the nuclei of AMs and upregulated in conventional AMs compared to unicystic AMs and normal oral epithelium. Compared with primary AM, FOSL1 expression was significantly increased in recurrent AM. Genetic knockdown of FOSL1 suppressed the proliferation, migration, invasion, and sphere formation of AMs. Similar results were also observed by pharmacological inhibition of AP-1 activity. Moreover, the AP-1 inhibitor T5224 impeded the growth of organoids derived from AM patients. Mechanistically, our Ingenuity Pathway Analysis (IPA) and gene set enrichment analysis (GSEA) results revealed that depletion of FOSL1 inactivated kinetochore metaphase signaling and the epithelial–mesenchymal transition pathway and then impaired the aggressiveness of AM cells accordingly.ConclusionFOSL1 promotes tumor recurrence and invasive growth in AM by modulating kinetochore metaphase signaling and the epithelial–mesenchymal transition pathway; thus, it represents a promising therapeutic target for AM treatment.

Data independent acquisition mass spectrometry in relation to potential diagnostic and prognostic biomarkers for high-grade serous ovarian cancer.

e17564 Background: Ovarian cancer (OC) is one of the most common causes of cancer-related death among women worldwide. High-grade serous ovarian cancer (HGSOC) represents the major OC histological type, and challenges associated with its early detection and prediction of clinical outcomes significantly contribute to the high prevalence and poor prognosis of OC. Lack of reliable biomarkers further exacerbates the low survival rate of patients with HGSOC. Methods: In this study, we performed liquid chromatography data independent acquisition tandem-mass spectrometry (LC-DIA-MS/MS) experiments on depleted serum samples [26 HGSOC cases, 24 healthy controls (HCs)] to identify potential diagnostic and prognostic biomarkers for HGSOC. Results: A total of 1,148 proteins were identified in all samples combined, representing one of the largest quantifications in the serum proteome of OC to date. Among them, 122 proteins showed differential expressions between the serum proteome of HGSOC patients and HCs, including 109 up- and 14 down-regulated proteins in HGSOC. These potential diagnostic biomarkers were involved in the pathways related to immune response, TGF- β and IGF signaling, and lipid metabolism. Moreover, we performed Kaplan-Meier survival analysis on the HGSOC patients with and without recurrence, and identified several potential prognostic biomarkers highly associated with progression free survival (PFS). Using independent cohort samples, we validated the expression levels of HGSOC serum biomarker candidates using targeted proteomics approaches (MRM and PRM). In vitro functional assays revealed that some of these biomarkers may play an essential role in cancer cell migration and proliferation in HGSOC. Conclusions: In summary, our LC-DIA-MS/MS analysis of the HGSOC serum proteome successfully identified novel diagnostic and prognostic biomarkers for HGSOC, some of which were experimentally shown to have functional relevance to the pathophysiology of OC.

Castanospermine suppresses CD44 ectodomain cleavage as revealed by transmembrane bioluminescent sensors.

Cluster of differentiation 44 (CD44) is a single-pass transmembrane glycoprotein that is a widely distributed cell-surface adhesion molecule. CD44 undergoes ectodomain cleavage by membrane-associated metalloproteinases in breast cancer cells. Cleavage plays a critical role in cancer cell migration by mediating the interaction between CD44 and the extracellular matrix. To explore inhibitors of CD44 ectodomain cleavage, we developed two bioluminescent sensors for the detection of CD44 ectodomain cleavage. The sensors were designed as two-transmembrane proteins with split-luciferase fragments, one of which was cyclized by protein trans-splicing of a DnaE intein. These two sensors emit light by the cyclization or the spontaneous complementation of the luciferase fragments. The luminescence intensities decreased upon cleavage of the ectodomain in breast cancer cells. The sensors revealed that castanospermine, an α-glucosidase inhibitor, suppressed the ectodomain cleavage of endogenous CD44 in breast cancer cells. Castanospermine also inhibited breast cancer cell invasion. Thus, the sensors are beneficial tools for evaluating the effects of different inhibitors.

Annexin A10 Expression as a Novel Prognostic Marker in Lung Adenocarcinoma.

Annexin A10 (ANXA10) is a member of the annexin family and a calcium-dependent phospholipid-binding protein. The aim of this study was to clarify the clinical significance of ANXA10 expression in lung adenocarcinoma. ANXA10 expression was immunohistochemically examined in surgical specimens of lung adenocarcinoma obtained from 74 consecutive patients who underwent complete resection from January 2014 to December 2014. Expression of ANXA10 was down-regulated in A549 cells via siRNA transfection and the effect of ANXA10 on cell migration was assessed by the wound healing assay. Expression of ANXA10 was examined by immunocytochemistry and polymerase chain reaction. High ANXA10 expression was significantly correlated with poor overall survival (p=0.00705). Multivariate analysis with the Cox proportional hazard model demonstrated that ANXA10 expression was an independent prognostic factor. Cell migration was suppressed in ANXA10-down-regulated A549 cell lines. ANXA10 has a role in cancer cell migration and high ANXA10 expression is a novel prognostic marker in lung adenocarcinoma.

Modulation of Cellular MicroRNA by HIV-1 in Burkitt Lymphoma Cells-A Pathway to Promoting Oncogenesis.

Viruses and viral components have been shown to manipulate the expression of host microRNAs (miRNAs) to their advantage, and in some cases to play essential roles in cancer pathogenesis. Burkitt lymphoma (BL), a highly aggressive B-cell derived cancer, is significantly over-represented among people infected with HIV. This study adds to accumulating evidence demonstrating that the virus plays a direct role in promoting oncogenesis. A custom miRNA PCR was used to identify 32 miRNAs that were differently expressed in Burkitt lymphoma cells exposed to HIV-1, with a majority of these being associated with oncogenic processes. Of those, hsa-miR-200c-3p, a miRNA that plays a crucial role in cancer cell migration, was found to be significantly downregulated in both the array and in single-tube validation assays. Using an in vitro transwell system we found that this downregulation correlated with significantly enhanced migration of BL cells exposed to HIV-1. Furthermore, the expression of the ZEB1 and ZEB2 transcription factors, which are promotors of tumour invasion and metastasis, and which are direct targets of hsa-miR-200c-3p, were found to be enhanced in these cells. This study therefore identifies novel miRNAs as role players in the development of HIV-associated BL, with one of these miRNAs, hsa-miR-200c-3p, being a candidate for further clinical studies as a potential biomarker for prognosis in patients with Burkitt lymphoma, who are HIV positive.

Nitric Oxide-Releasing Drug Glyceryl Trinitrate Targets JAK2/STAT3 Signaling, Migration and Invasion of Triple-Negative Breast Cancer Cells.

Triple-negative breast cancer (TNBC) is a highly aggressive disease with invasive and metastasizing properties associated with a poor prognosis. The STAT3 signaling pathway has shown a pivotal role in cancer cell migration, invasion, metastasis and drug resistance of TNBC cells. IL-6 is a main upstream activator of the JAK2/STAT3 pathway. In the present study we examined the impact of the NO-donor glyceryl trinitrate (GTN) on the activation of the JAK2/STAT3 signaling pathway and subsequent migration, invasion and metastasis ability of TNBC cells through in vitro and in vivo experiments. We used a subtoxic dose of carboplatin and/or recombinant IL-6 to activate the JAK2/STAT3 signaling pathway and its functional outcomes. We found an inhibitory effect of GTN on the activation of the JAK2/STAT3 signaling, migration and invasion of TNBC cells. We discovered that GTN inhibits the activation of JAK2, the upstream activator of STAT3, and mediates the S-nitrosylation of JAK2. Finally, the effect of GTN (Nitronal) on lung metastasis was investigated to assess its antitumor activity in vivo.

METTL8 mRNA Methyltransferase Enhances Cancer Cell Migration via Direct Binding to ARID1A.

The association of RNA modification in cancer has recently been highlighted. Methyltransferase like 8 (METTL8) is an enzyme and its role in mRNA m3C modification has barely been studied. In this study, we found that METTL8 expression was significantly up-regulated in canine mammary tumor and investigated its functional roles in the tumor process, including cancer cell proliferation and migration. METTL8 expression was up-regulated in most human breast cancer cell lines tested and decreased by Yin Yang 1 (YY1) transcription factor knockdown, suggesting that YY1 is a regulating transcription factor. The knockdown of METTL8 attenuated tumor cell growth and strongly blocked tumor cell migration. AT-rich interactive domain-containing protein 1A (ARID1A) was identified as a candidate mRNA by METTL8. ARID1A mRNA binds to METTL8 protein. ARID1A mRNA expression was not changed by METTL8 knockdown, but ARID1A protein level was significantly increased. Collectively, our study indicates that METTL8 up-regulated by YY1 in breast cancer plays an important role in cancer cell migration through the mRNA modification of ARID1A, resulting in the attenuation of its translation.

Kv3 channels contribute to cancer cell migration via vimentin regulation

Cell migration is a complex and important process in cancer progression. Vimentin has pivotal roles in cancer cell migration, and various signaling pathways including the AKT pathway are involved in cancer cell migration via vimentin regulation. Recent studies have revealed that voltage-gated potassium (Kv) channels have important functions in cancer cell migration; however, the exact mechanism is still unclear. In the present study, we focused on Kv3 channels with vimentin in cancer migration using human cervical cancer cells (HeLa) and canine mammary tumor cells (CHMp). Cancer cell migration was significantly inhibited, and vimentin expression was significantly decreased by Kv3 blocker, BDS-II. The Kv3 blocker also inactivated the AKT pathway in HeLa cells. In addition, reduced expressions of vimentin and Kv3.4 were observed in HeLa cells when treated with AKT blocker, MK2206. These results suggest that Kv3 channels play important roles in cancer cell migration by regulating vimentin and having closely related with the AKT pathway in human cervical cancer cells.

Green Curmin reduces pro-inflammatory cytokines and fibroblast-associated colon cancer migration

Introduction: Green Curmin is a soluble curcumin extract product made in Thailand and reported to reduce gastric inflammation. Inflammatory cytokines including IL-1α, IL-6 and TNF-β play a crucial role in cancer cell migration, which is a major process towards poor prognosis. Objective: To investigate the effects of Green Curmin on colon cancer cell growth and migration, which involve the pro-inflammatory cytokines. Method: Curcuma longa, L. were extracted and named as Green Curmin. The cytotoxicity of the Green Curmin-treated HCT116-colon cancer cells was obtained by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. The effect of the extract on cancer migration was investigated with wound healing assay. In addition, fibroblast-associated cancer migration was confirmed by using Transwell migration assay. Pro-inflammatory cytokines were also determined. Results: Green Curmin had cytotoxicity in the induced-cancer cell apoptosis at concentrations of 1 and 5 mg/ml. However, at concentrations of 0.05 and 0.1 mg/ml (non-toxicity dose), andreduced colon cancer migration and fibroblast associated-cancer migration. They also suppressed pro-inflammatory cytokines expression including IL-1α, IL-6 and TNF-β in colon cancer cells and IL-6 in fibroblast cells. Conclusion: Green Curmin suppressed pro-inflammatory cytokines and reduced fibroblast associated-cancer migration.

EB1 Restricts Breast Cancer Cell Invadopodia Formation and Matrix Proteolysis via FAK

Regulation of microtubule dynamics by plus-end tracking proteins (+TIPs) plays an essential role in cancer cell migration. However, the role of +TIPs in cancer cell invasion has been poorly addressed. Invadopodia, actin-rich protrusions specialized in extracellular matrix degradation, are essential for cancer cell invasion and metastasis, the leading cause of death in breast cancer. We, therefore, investigated the role of the End Binding protein, EB1, a major hub of the +TIP network, in invadopodia functions. EB1 silencing increased matrix degradation by breast cancer cells. This was recapitulated by depletion of two additional +TIPs and EB1 partners, APC and ACF7, but not by the knockdown of other +TIPs, such as CLASP1/2 or CLIP170. The knockdown of Focal Adhesion Kinase (FAK) was previously proposed to similarly promote invadopodia formation as a consequence of a switch of the Src kinase from focal adhesions to invadopodia. Interestingly, EB1-, APC-, or ACF7-depleted cells had decreased expression/activation of FAK. Remarkably, overexpression of wild type FAK, but not of FAK mutated to prevent Src recruitment, prevented the increased degradative activity induced by EB1 depletion. Overall, we propose that EB1 restricts invadopodia formation through the control of FAK and, consequently, the spatial regulation of Src activity.

PtdIns(4,5)P2 and PtdIns(3,4,5)P3 dynamics during focal adhesions assembly and disassembly in a cancer cell line.

Focal adhesions (FAs) are large assemblies of proteins that mediate intracellular signals between the cytoskeleton and the extracellular matrix (ECM). The turnover of FA proteins plays a critical regulatory role in cancer cell migration. Plasma membrane lipids locally generated or broken down by different inositide kinases and phosphatase enzymes to activate and recruit proteins to specific regions in the plasma membrane. Presently, little attention has been given to the use of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2) and Phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P3) fluorescent biosensors in order to determine the spatiotemporal organisation of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 within and around or during assembly and disassembly of FAs. In this study, specific biosensors were used to detect PtdIns(4,5)P2, PtdIns(3,4,5)P3, and FAs proteins conjugated to RFP/GFP in order to monitor changes of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 levels within FAs. We demonstrated that the localisation of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 were moderately correlated with that of FA proteins. Furthermore, we demonstrate that local levels of PtdIns(4,5)P2 increased within FA assembly and declined within FA disassembly. However, PtdIns(3,4,5)P3 levels remained constant within FAs assembly and disassembly. In conclusion, this study shows that PtdIns(4,5)P2 and PtdIns(3,4,5)P3 localised in FAs may be regulated differently during FA assembly and disassembly.

Neddylation blockade induces HIF-1\u03b1 driven cancer cell migration via upregulation of ZEB1

Neddylation is a process by which NEDD8 is covalently conjugated to target proteins by sequential enzymatic reaction. Its role in cancer cell migration has only been recently acknowledged. Previously in cancer cell migration, the epithelial to mesenchymal transition (EMT) process has been well-known to play an important role in both invasion and metastasis by promoting mesenchymal phenotype in epithelial cells. However, the role of neddylation in the EMT process and its mechanistic details are yet to be elucidated. We recently reported that neddylation plays a crucial role in cancer cell migration through the PI3K-Akt pathway. Here, we report that inhibiting neddylation activates the hypoxia-inducible factor 1α (HIF-1α) through the PI3K-Akt pathway, which eventually regulates the EMT-activator ZEB1 (zinc finger E-box binding homeobox 1) in various cancer cell lines. As induction of HIF-1α is known to deteriorate the state of cancer and EMT process is one of the hallmarks of metastasis in cancer, our findings uncover the role of neddylation between HIF-1α and ZEB1.