ITIH5 as a multifaceted player in pancreatic cancer suppression, impairing tyrosine kinase signaling, cell adhesion and migration.

Inter-alpha-trypsin inhibitor heavy chain 5 (ITIH5) has been identified as a metastasis suppressor gene in pancreatic cancer. Here, we analyzed ITIH5 promoter methylation and protein expression in The Cancer Genome Atlas (TCGA) dataset and three tissue microarray cohorts (n = 618), respectively. Cellular effects, including cell migration, focal adhesion formation and protein tyrosine kinase activity, induced by forced ITIH5 expression in pancreatic cancer cell lines were studied in stable transfectants. ITIH5 promoter hypermethylation was associated with unfavorable prognosis, while immunohistochemistry demonstrated loss of ITIH5 in the metastatic setting and worsened overall survival. Gain-of-function models showed a significant reduction in migration capacity, but no alteration in proliferation. Focal adhesions in cells re-expressing ITIH5 exhibited a smaller and more rounded phenotype, typical for slow-moving cells. An impressive increase of acetylated alpha-tubulin was observed in ITIH5-positive cells, indicating more stable microtubules. In addition, we found significantly decreased activities of kinases related to focal adhesion. Our results indicate that loss of ITIH5 in pancreatic cancer profoundly affects its molecular profile: ITIH5 potentially interferes with a variety of oncogenic signaling pathways, including the PI3K/AKT pathway. This may lead to altered cell migration and focal adhesion formation. These cellular alterations may contribute to the metastasis-inhibiting properties of ITIH5 in pancreatic cancer.

Remodeling of intestinal epithelium derived extracellular vesicles by nanoparticles and its bioeffect on tumor cell migration.

Extracellular vesicles (EVs) are an effective tool to elucidate the bioeffect of nanomedicines. To clarify the interaction between oral nanomedicines and intestinal epithelial cells, and their bioeffects on downstream cells, polystyrene nanoparticles (PS-NPs) with different sizes were used as the model nanomedicines for EVs induction. Caco-2 monolayers were selected as the model of the intestinal epithelium and DLD-1 cells as the colorectal cancer model proximal to the gastrointestinal tract. It is found that compared with small-sized (25, 50, 100 nm) PS-NPs, the large-sized (200 and 500 nm) exhibited higher co-localization with multivesicular bodies and lysosomes, and more significant reduction of lysosomal acidification in Caco-2 cells. Proteomic and western-blotting analysis showed that the EVs remodeled by large-sized PS-NPs exhibited a higher extent of protein expression changes. The in vitro and in vivo signaling pathway detection in DLD-1 cells and DLD-1 cell xenograft nude mice showed that the remodeled EVs by large-sized PS-NPs inhibited the activation of multiple signaling pathways including Notch3, EGF/EGFR, and PI3K/Akt pathways, which resulted in the inhibition of tumor cell migration. These results primarily clarify the regulation mechanisms of nanomedicines-EVs-receptor cells chain. It provides a new perspective for the rational design and bioeffect evaluation of oral drug nanomaterials and sets up the fundamental knowledge for novel tumor therapeutics in the future.

Tumor Microenvironment Remodeling in Gastrointestinal Cancer: Role of miRNAs as Biomarkers of Tumor Invasion.

Gastrointestinal (GI) cancers are the most frequent neoplasm, responsible for half of all cancer-related deaths. Metastasis is the leading cause of death from GI cancer; thus, studying the processes that regulate cancer cell migration is of paramount importance for the development of new therapeutic strategies. In this review, we summarize the mechanisms adopted by cancer cells to promote cell migration and the subsequent metastasis formation by highlighting the key role that tumor microenvironment components play in deregulating cellular pathways involved in these processes. We, therefore, provide an overview of the role of different microRNAs in promoting tumor metastasis and their role as potential biomarkers for the prognosis, monitoring, and diagnosis of GI cancer patients. Finally, we relate the possible use of nutraceuticals as a new strategy for targeting numerous microRNAs and different pathways involved in GI tumor invasiveness.

The 3q Oncogene SEC62 Predicts Response to Neoadjuvant Chemotherapy and Regulates Tumor Cell Migration in Triple Negative Breast Cancer.

In the absence of targeted treatment options, neoadjuvant chemotherapy (NACT) is applied widely for triple-negative breast cancer (TNBC). Response to NACT is an important parameter predictive of oncological outcomes (progression-free and overall survival). An approach to the evaluation of predictive markers enabling therapy individualization is the identification of tumor driver genetic mutations. This study was conducted to investigate the role of SEC62, harbored at 3q26 and identified as a driver of breast cancer pathogenesis, in TNBC. We analyzed SEC62 expression in The Cancer Genome Atlas database, and immunohistologically investigated SEC62 expression in pre- and post-NACT tissue samples from 64 patients with TNBC treated at the Department of Gynecology and Obstetrics/Saarland University Hospital/Homburg between January 2010 and December 2018 and compared the effect of SEC62 on tumor cell migration and proliferation in functional assays. SEC62 expression dynamics correlated positively with the response to NACT (p ≤ 0.01) and oncological outcomes (p ≤ 0.01). SEC62 expression stimulated tumor cell migration (p ≤ 0.01). The study findings indicate that SEC62 is overexpressed in TNBC and serves as a predictive marker for the response to NACT, a prognostic marker for oncological outcomes, and a migration-stimulating oncogene in TNBC.

Overexpression of miR-4669 Enhances Tumor Aggressiveness and Generates an Immunosuppressive Tumor Microenvironment in Hepatocellular Carcinoma: Its Clinical Value as a Predictive Biomarker.

Accumulating evidence suggests the involvement of tumor-derived exosomes in the development and recurrence of hepatocellular carcinoma (HCC). We previously identified miR-4669 as a highly expressed microRNA in circulating exosomes obtained from patients with post-transplant HCC recurrence. This study aimed to explore how overexpression of miR-4669 affects HCC development and recurrence. The impact of miR-4669 overexpression in Hep3B cells on tumor cell behavior and the tumor microenvironment was evaluated in vitro. In addition, the clinical value of exosomal miR-4669 for the prediction of treatment response to HCC downstaging therapies and following post-transplant HCC recurrence was explored. Overexpression of miR-4669 enhanced migration ability and led to acquired sorafenib resistance with an elevation of sirtuin 1 and long noncoding RNA associated with microvascular invasion. Active release of tumor-derived exosomes and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) contributed to generating an immunosuppressive tumor microenvironment through the induction of M2 macrophage polarization. The retrospective analysis demonstrated the clinical value of exosomal miR-4669 for predicting treatment response to HCC downstaging therapies and for risk assessment of post-transplant HCC recurrence. In summary, the present data demonstrate the impact of exosomal miR-4669 on HCC recurrence through the enhancement of tumor aggressiveness and generation of an immunosuppressive tumor microenvironment.

Neutrophils Promote Glioblastoma Tumor Cell Migration after Biopsy.

Glioblastoma is diagnosed by biopsy or, if clinically feasible, tumor resection. However, emerging evidence suggests that this surgical intervention may increase the risk of tumor cell spread. It has been hypothesized that the damage to the tumor leads to infiltration of immune cells that consequently form an environment that favors tumor cell motility. In mouse glioma models, it was previously found that biopsy induced migration of tumor cells in vivo and that recruitment of monocytes from the blood was involved in this effect. However, the role of neutrophils in this process is still unclear. Here, we study the contribution of neutrophils on the pro-migratory effect of surgical interventions in glioma. Using repetitive intravital microscopy, in vivo migration of glioma tumor cells before and after biopsy was compared in mice systemically depleted of neutrophils. Interestingly, macrophages/microglia were almost completely absent from neutrophil-depleted tumors, indicating that neutrophils may be indirectly involved in biopsy-induced migration of glioma tumor cells through the recruitment of macrophages to the tumor. To further investigate whether neutrophils have the potential to also directly promote glioblastoma tumor cell migration, we performed in vitro migration assays using human neutrophils. Indeed, wound-healing of human primary glioblastoma tumor cell lines was promoted by human neutrophils. The pro-migratory effects of human neutrophils on glioblastoma tumor cells could also be recapitulated in transwell migration assays, indicating that soluble factor(s) are involved. We therefore provide evidence for both an indirect and direct involvement of neutrophils in tumor spread following biopsy of glioblastoma tumors.

Diaph3 underlines tumor cell heterogeneity in glioblastoma with implications for treatment modalities resistance.

INTRODUCTION: Glioblastoma (GBM) is the most aggressive central nervous system (CNS) tumor with astrocytic differentiation. The growth pattern of GBM mimics that of the precursor cell migration during the fetal development of the brain. Diaphanous homolog (Diaph3) has been established to play a role in both CNS maturation and cancer progression as it is required both for cell migration and division. Furthermore, Diaph3 has been shown to play a role in malignant disease progression through hyperactivation of the EGFR/MEK/ERK in loss of expression and its overexpression correlating to hyperactivity of the mTOR pathway, both of which are with a well-established role in GBM. Herein, we aimed at establishing the diagnostic role of Diaph3 immunohistochemistry expression patterns in GBM and their possible implications for molecular response to different therapies. MATERIALS AND METHODS: The study utilized a retrospective nonclinical approach. Results of Diaph3 immunohistochemical expression were compared to healthy controls and reactive gliosis and statistically analyzed for correlation with neuroradiological tumor parameters and patient survival. RESULTS: Healthy controls showed individual weakly positive cells, while reactive gliosis controls showed a strong expression in astrocytic projections. GBM samples showed a heterogeneous positive reaction to Diaph3, mean number of positive cells 62.66%, median 61.5, range 12-96%. Areas of migrating cells showed a strong diffuse cytoplasmic reaction. Cells located in the tumor core and those in areas of submeningeal aggregation had no antibody expression. Statistical analysis revealed no correlation with tumor size or patient survival. CONCLUSION: The different expression pattern of Diaph3 in healthy controls, reactive gliosis and GBM shows promise as a clinical differentiating marker. Despite Diaph3 expression not correlating with survival and tumor size in GBM, there is an accumulating body of evidence that Diaph3 correlates with mTOR activity and can thus be used as a predictor for response to rapamycin and taxanes, clinical studies of which have shown promising, if mixed results in GBM.

Macrophages Actively Transport Nanoparticles in Tumors After Extravasation.

Nanoparticles need to navigate a complex microenvironment to target cells in solid tumors after extravasation. Diffusion is currently the accepted primary mechanism for nanoparticle distribution in tumors. However, the extracellular matrix can limit nanoparticle diffusion. Here, we identified tumor-associated macrophages as another key player in transporting and redistributing nanoparticles in the tumor microenvironment. We found tumor-associated macrophages actively migrate toward nanoparticles extravasated from the vessels, engulfing and redistributing them in the tumor stroma. The macrophages can carry the nanoparticles 2-5 times deeper in the tumor than passive diffusion. The amount of nanoparticles transported by the tumor-associated macrophages is size-dependent. Understanding the nanoparticle behavior after extravasation will provide strategies to engineer them to navigate the microenvironment for improved intratumoral targeting and therapeutic effectiveness.

The Solute Carrier MFSD1 Decreases the Activation Status of ß1 Integrin and Thus Tumor Metastasis.

Solute carriers are increasingly recognized as participating in a plethora of pathologies, including cancer. We describe here the involvement of the orphan solute carrier Major Facilitator Superfamily Domain-containing protein 1 (MFSD1) in the regulation of tumor cell migration. Loss of MFSD1 enabled higher levels of metastasis in experimental and spontaneous metastasis mouse models. We identified an increased migratory potential in MFSD1-/- tumor cells which was mediated by increased focal adhesion turnover, reduced stability of mature inactive ß1 integrin, and the resulting increased integrin activation index. We show that MFSD1 promoted recycling to the cell surface of endocytosed inactive ß1 integrin and thereby protected ß1 integrin from proteolytic degradation; this led to dampening of the integrin activation index. Furthermore, downregulation of MFSD1 expression was observed during the early steps of tumorigenesis, and higher MFSD1 expression levels correlate with a better cancer patient prognosis. In sum, we describe a requirement for endolysosomal MFSD1 in efficient ß1 integrin recycling to suppress tumor cell dissemination.

hsa －let－7e－5p inhibits the migration of lung adenocarcinoma cells / 安徽医科大学学报

Objective @#To screen differentially expressed miRNAs and explore its effect and mechanism on cell mi- gration in lung adenocarcinoma (LUAD) ．@*Methods @#Differentially expressed miRNAs in LUAD tissues and normal lung tissues were screened by miRNA microarrays，and then bioinformatics analysis was used to predict their poten- tial biological functions and signaling pathways．The cancer genome atlas (TCGA) analysis and quantitative real- time PCR (qRT-PCR) verified the expression level of hsa-let-7e-5p in LUAD tissues and cell lines．The effect of hsa-let-7e-5p cell migration in LUAD was examined by would healing experiment．After screening the underlying target genes by bioinformatics analysis ，the targeting relationship between hsa-let-7e-5p and DTX2，NME6， C8orf58，GATM and DHX57 were verified by qRT-PCR. @*Results @#The miRNA microarray results showed that 347 miRNAs were down-regulated while 229 miRNAs were up-regulated in lung adenocarcinoma tissues．Compared with normal lung tissue and cells，the expression level of hsa-let-7e-5p was significantly down-regulated．Besides，over- expression of hsa-let-7e-5p inhibitedLUAD cell migration．@*Conclusion @#Non-coding RNA hsa-let-7e-5p is down- regulated in LUAD and inhibits the migration of lung adenocarcinoma cells．DTX2，NME6，C8orf58，GATM and DHX57 are the potential target genes of hsa-let-7e-5p.

Transmembrane Protein TMEM230, a Target of Glioblastoma Therapy.

Glioblastomas (GBM) are the most aggressive tumors originating in the brain. Histopathologic features include circuitous, disorganized, and highly permeable blood vessels with intermittent blood flow. These features contribute to the inability to direct therapeutic agents to tumor cells. Known targets for anti-angiogenic therapies provide minimal or no effect in overall survival of 12-15 months following diagnosis. Identification of novel targets therefore remains an important goal for effective treatment of highly vascularized tumors such as GBM. We previously demonstrated in zebrafish that a balanced level of expression of the transmembrane protein TMEM230/C20ORF30 was required to maintain normal blood vessel structural integrity and promote proper vessel network formation. To investigate whether TMEM230 has a role in the pathogenesis of GBM, we analyzed its prognostic value in patient tumor gene expression datasets and performed cell functional analysis. TMEM230 was found necessary for growth of U87-MG cells, a model of human GBM. Downregulation of TMEM230 resulted in loss of U87 migration, substratum adhesion, and re-passaging capacity. Conditioned media from U87 expressing endogenous TMEM230 induced sprouting and tubule-like structure formation of HUVECs. Moreover, TMEM230 promoted vascular mimicry-like behavior of U87 cells. Gene expression analysis of 702 patients identified that TMEM230 expression levels distinguished high from low grade gliomas. Transcriptomic analysis of patients with gliomas revealed molecular pathways consistent with properties observed in U87 cell assays. Within low grade gliomas, elevated TMEM230 expression levels correlated with reduced overall survival independent from tumor subtype. Highest level of TMEM230 correlated with glioblastoma and ATP-dependent microtubule kinesin motor activity, providing a direction for future therapeutic intervention. Our studies support that TMEM230 has both glial tumor and endothelial cell intracellular and extracellular functions. Elevated levels of TMEM230 promote glial tumor cell migration, extracellular scaffold remodeling, and hypervascularization and abnormal formation of blood vessels. Downregulation of TMEM230 expression may inhibit both low grade glioma and glioblastoma tumor progression and promote normalization of abnormally formed blood vessels. TMEM230 therefore is both a promising anticancer and antiangiogenic therapeutic target for inhibiting GBM tumor cells and tumor-driven angiogenesis.

AQP1 Is Up-Regulated by Hypoxia and Leads to Increased Cell Water Permeability, Motility, and Migration in Neuroblastoma.

The water channel aquaporin 1 (AQP1) has been implicated in tumor progression and metastasis. It is hypothesized that AQP1 expression can facilitate the transmembrane water transport leading to changes in cell structure that promote migration. Its impact in neuroblastoma has not been addressed so far. The objectives of this study have been to determine whether AQP1 expression in neuroblastoma is dependent on hypoxia, to demonstrate whether AQP1 is functionally relevant for migration, and to further define AQP1-dependent properties of the migrating cells. This was determined by investigating the reaction of neuroblastoma cell lines, particularly SH-SY5Y, Kelly, SH-EP Tet-21/N and SK-N-BE(2)-M17 to hypoxia, quantitating the AQP1-related water permeability by stopped-flow spectroscopy, and studying the migration-related properties of the cells in a modified transwell assay. We find that AQP1 expression in neuroblastoma cells is up-regulated by hypoxic conditions, and that increased AQP1 expression enabled the cells to form a phenotype which is associated with migratory properties and increased cell agility. This suggests that the hypoxic tumor microenvironment is the trigger for some tumor cells to transition to a migratory phenotype. We demonstrate that migrating tumor cell express elevated AQP1 levels and a hypoxic biochemical phenotype. Our experiments strongly suggest that elevated AQP1 might be a key driver in transitioning stable tumor cells to migrating tumor cells in a hypoxic microenvironment.

Transport Metabolons and Acid/Base Balance in Tumor Cells.

Solid tumors are metabolically highly active tissues, which produce large amounts of acid. The acid/base balance in tumor cells is regulated by the concerted interplay between a variety of membrane transporters and carbonic anhydrases (CAs), which cooperate to produce an alkaline intracellular, and an acidic extracellular, environment, in which cancer cells can outcompete their adjacent host cells. Many acid/base transporters form a structural and functional complex with CAs, coined "transport metabolon". Transport metabolons with bicarbonate transporters require the binding of CA to the transporter and CA enzymatic activity. In cancer cells, these bicarbonate transport metabolons have been attributed a role in pH regulation and cell migration. Another type of transport metabolon is formed between CAs and monocarboxylate transporters, which mediate proton-coupled lactate transport across the cell membrane. In this complex, CAs function as "proton antenna" for the transporter, which mediate the rapid exchange of protons between the transporter and the surroundings. These transport metabolons do not require CA catalytic activity, and support the rapid efflux of lactate and protons from hypoxic cancer cells to allow sustained glycolytic activity and cell proliferation. Due to their prominent role in tumor acid/base regulation and metabolism, transport metabolons might be promising drug targets for new approaches in cancer therapy.

Visualization and Quantification of 3D Tumor Cell Migration under Extracellular Stimulation.

To investigate tumor cell migration capability, the scratch/wound healing assay and the Transwell assay are the most commonly used assays in the current biomedical research laboratory. However, both assays have their limitations and may mislead the interpretation of the results. In the current study, visualization and quantification of tumor cell migration process was realized in a three-dimensional (3D) environment. The tumor cells horizontally migrated along a Matrigel-filled microchannel under extracellular stimulation. The cell migration process was visualized under a microscope, and the migration speed could be calculated based on the traveling distance of the cells and the time required. Here, three demonstrations were conducted, respectively, including cells attracted by nutrient gradient, stimulated by cytokine, and coculturing with fibroblasts. The results revealed that the cell migration capability could be visually and quantitatively correlated to the extracellular stimulation. The current protocol is compatible to the existing laboratory setup and provides a persuasive result for the study of the 3D cell migration process. Understanding of the molecular and intercellular mechanism of cancer metastasis can potentially develop effective therapeutic strategy.

Textures of the tumour microenvironment.

In this review, we present recent findings on the dynamic nature of the tumour microenvironment (TME) and how intravital microscopy studies have defined TME components in a spatiotemporal manner. Intravital microscopy has shed light into the nature of the TME, revealing structural details of both tumour cells and other TME co-habitants in vivo, how these cells communicate with each other, and how they are organized in three-dimensional space to orchestrate tumour growth, invasion, dissemination and metastasis. We will review different imaging tools, imaging reporters and fate-mapping strategies that have begun to uncover the complexity of the TME in vivo.

CXCL1-LCN2 paracrine axis promotes progression of prostate cancer via the Src activation and epithelial-mesenchymal transition.

BACKGROUND: Mechanisms driving the progression of castration-resistant prostate cancer are believed to relate substantially to the tumor microenvironment. However, the cross-talks between tumor epithelial cell, stromal cells, and immune cells are yet to be fully elucidated. The present study aims to determine the role of chemokine and neutrophil derived cytokine paracrine axis in mediating the interaction between tumor cells, stromal myofibroblasts, and neutrophils in the tumor microenvironment of prostate cancer. METHODS: To identify myofibroblasts and neutrophil derived specific proteins affecting progression of prostate cancer, bioinformatics analyses were firstly performed in independent human prostate cancer gene expression data sets from the GEO data bank. Expression of stromal myofibroblasts secretory chemokine CXCL1 and neutrophil derived cytokine LCN2 was evaluated in prostate tissues via immunohistochemistry assay. We further investigated the effect of CXCL1 and LCN2 on prostate cancer using in vivo and in vitro models, and explored the underlying signal transduction pathways. RESULTS: A CXCL1-LCN2 paracrine network was confirmed in prostate cancer tissue samples, which was correlated with the biochemical recurrence of prostate cancer. Of note, CXCL1-LCN2 axis activates Src signaling, triggers the epithelial-mesenchymal transition (EMT), consequently promotes the migration of prostate cancer cells, leading to enhanced tumor metastasis. CONCLUSIONS: Our findings may provide enhanced insight into the interactions of carcinoma-stromal cells and immune cells linked to prostate cancer progression, wherein CXCL1-LCN2 axis is a key contributor to prostate cancer cells migration. These data indicate tumor microenvironment and Src signaling pathway may be potential therapeutic targets of prostate cancer treatment.

Reversing the Tumor Target: Establishment of a Tumor Trap.

Despite the tremendous progress made in the field of cancer therapy in recent years, certain solid tumors still cannot be successfully treated. Alongside classical treatments in the form of chemotherapy and/or radiotherapy, targeted treatments such as immunotherapy that cause fewer side effects emerge as new options in the clinics. However, these alternative treatments may not be useful for treating all types of cancers, especially for killing infiltrative and circulating tumor cells (CTCs). Recent advances pursue the trapping of these cancer cells within a confined area to facilitate their removal for therapeutic and diagnostic purposes. A good understanding of the mechanisms behind tumor cell migration may drive the design of traps that mimic natural tumor niches and guide the movement of the cancer cells. To bring this trapping idea into reality, strong efforts are being made to create structured materials that imitate myelinated fibers, blood vessels, or pre-metastatic niches and incorporate chemical cues such as chemoattractants or adhesive proteins. In this review, the different strategies used (or could be used) to trap tumor cells are described, and relevant examples of their performance are analyzed.

Overexpression and Tyr421-phosphorylation of cortactin is induced by three-dimensional spheroid culturing and contributes to migration and invasion of pancreatic ductal adenocarcinoma (PDAC) cells.

BACKGROUND: The nucleation-promoting factor cortactin is expressed and promotes tumor progression and metastasis in various cancers. However, little is known about the biological role of cortactin in the progression of pancreatic ductal adenocarcinoma (PDAC). METHODS: Cortactin and phosphorylated cortactin (Y421) were investigated immunohistochemically in 66 PDAC tumor specimens. To examine the functional role of cortactin in PDAC, we modulated cortactin expression by establishing two cortactin knockout cell lines (Panc-1 and BxPC-3) with CRISPR/Cas9 technique. Cortactin knockout was verified by immunoblotting and immunofluorescence microscopy and functional effects were determined by cell migration and invasion assays. A proteomic screening approach was performed to elucidate potential binding partners of cortactin. RESULTS: Immunohistochemically, we observed higher cortactin expression and Tyr421-phosphorylation in PDAC metastases compared to primary tumor tissues. In PDAC cell lines Panc-1 and BxPC-3, knockdown of cortactin impaired migration and invasion, while cell proliferation was not affected. Three-dimensional spheroid culturing as a model for collective cell migration enhanced cortactin expression and Tyr421-phosphorylation. The activation of cortactin as well as the migratory capacity of PDAC cells could significantly be reduced by dasatinib, a Src family kinase inhibitor. Finally, we identified gelsolin as a novel protein interaction partner of cortactin in PDAC. CONCLUSION: Our data provides evidence that cohesive cell migration induces cortactin expression and phosphorylation as a prerequisite for the gain of an invasive, pro-migratory phenotype in PDAC that can effectively be targeted with dasatinib.

Breast cancer cell motility is promoted by 14-3-3γ.

PURPOSE: Pseudopodia are actin-rich ventral protrusions associated with cell motility and cancer cell invasion. We previously applied our established method of using excimer laser cell etching to isolate pseudopodial proteins from MDA-MB-231 breast cancer cells. We later identified 14-3-3γ as an oncogenic molecule among 46 candidate proteins that are specific to pseudopodia. The present study aimed to determine the function of 14-3-3γ in the motility of breast cancer cells. METHODS: MDA-MB-231 cells were cultured on 3-µm porous membranes and double stained to localize 14-3-3γ and phalloidin in pseudopodia using confocal imaging. We assessed pseudopodia numbers and length, as well as migration and wound healing in MDA-MB-231 cells with knockdown and forced expression of 14-3-3γ to determine 14-3-3γ involvement in cell motility. We also immunohistochemically analyzed 14-3-3γ in human breast cancer tissues with high-grade lymphatic invasion. RESULTS: We specifically located 14-3-3γ in pseudopodia of MDA-MB-231 cells. Knockdown and forced expression of 14-3-3γ, respectively, decreased and increased pseudopodial formation and elongation. Migration and wound healing assays also showed that 14-3-3γ knockdown and forced expression, respectively, decreased and increased the number of underside cells and acellular areas in MDA-MB-231 breast cancer cells. More 14-3-3γ was expressed in sites of lymphatic invasion, than in the center and periphery of human breast cancer tissues. CONCLUSION: The role of 14-3-3γ in breast cancer invasiveness might be to promote cell motility. Inhibition of 14-3-3γ could, therefore, become a novel target of therapy to prevent invasion and metastasis in patients with breast cancers expressing 14-3-3γ.

Chemoenzymatically synthesized ganglioside GM3 analogues with inhibitory effects on tumor cell growth and migration.

Ganglioside GM3, belonging to glycosphingolipid family, has been known as tumor-associated carbohydrate antigen on several types of tumor. Many studies have revealed that GM3 plays a role in cell proliferation, adhesion and differentiation, which is crucial in the process of cancer development. In the present study, we firstly synthesized novel mannose-containing GM3 analogues by enzymatic hydrolysis and chemical procedures. Then the antiproliferative activity of the novel analogues along with galactose-containing analogues we prepared previously was investigated and the data demonstrated that these analogues exhibited antiproliferative effect on K562 and HCT116 cells. Finally, the influence of these analogues on tumor cell migration was studied on B16, B16-F10 and HCCLM3 cells by wound healing test, because the migration of tumor cells represents one of the relevant factors in assessing the malignancy of cancer. This study could lay the foundation for optimizing leading compounds and provide valuable information for finding new antitumor drugs for cancer therapy.