Non-invasive Cells Research Articles

MP17-04 NOVEL HYALURONIDASE TMEM2 EXPRESSION OF BLADDER TUMOR IS ALTERED BY INDUCING EMT-MET PROCESS

You have accessJournal of UrologyBladder Cancer: Basic Research & Pathophysiology II (MP17)1 Apr 2020MP17-04 NOVEL HYALURONIDASE TMEM2 EXPRESSION OF BLADDER TUMOR IS ALTERED BY INDUCING EMT-MET PROCESS Mihoko Yoneyama*, Tohru Yoneyama, Hayato Yamamoto, Yuki Tobisawa, Shingo Hatakeyama, Senji Hoshi, Shigeru Tsuboi, Tadashi Suzuki, and Chikara Ohyama Mihoko Yoneyama*Mihoko Yoneyama* More articles by this author , Tohru YoneyamaTohru Yoneyama More articles by this author , Hayato YamamotoHayato Yamamoto More articles by this author , Yuki TobisawaYuki Tobisawa More articles by this author , Shingo HatakeyamaShingo Hatakeyama More articles by this author , Senji HoshiSenji Hoshi More articles by this author , Shigeru TsuboiShigeru Tsuboi More articles by this author , Tadashi SuzukiTadashi Suzuki More articles by this author , and Chikara OhyamaChikara Ohyama More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000842.04AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: As a major component of ECM, Hyaluronic acid (HA) fragments different molecular sizes exhibit different biological actions and biological responses. While high molecular weight (HMW) HA inhibits the cell motility and tumor proliferation, it has been reported that low MW HA has enhanced the cell migration/invasion and increased apoptosis. Recently, we identified transmembrane protein 2 (TMEM2) as a novel hyaluronidase that degraded HMW-HA into ∼5-kDa HA fragments. There are few data on TMEM2 involvement in human cancer. In this study, we investigated that association between TMEM2 expression and bladder cancer (BCa) progression. METHODS: TMEM2 expression of BCacells were examined by western blotting and droplet digital PCR. To examine the association of TMEM2 expression during EMT-MET process,we performed spheroid formation assay by using RT4-EMT and, 5637-EMT cell lines which isolated from the noninvasive RT4 and 5637 BCa cell line. To assess hyaluronidase activity of TMEM2, we examined that BCa cells put on FITC-HMW-HA1500. To examine TMEM2 expression in radical cystectomy tissues, we performed immunohistochemical staining by using anti-TMEM2 polyclonal antibody and evaluated association between TMEM2 expression and pathological features. RESULTS: We showed TMEM2 expression were significantly lower invasive BCa cells than non-invasive BCa cells. BCa cells expressing TMEM2 exhibit hyaluronidase activity depending on its expression level. Although TMEM2 expression of EMT induced BCa cells (RT4-EMT and 5637-EMT) were significantly decreased and little hyaluronidase activity was observed, the TMEM2 expression of EMT induced BCa cells increased during spheroid formation and its expression level was positively correlated with spheroid volume. In addition, immunohistochemical analyze revealed that TMEM2 expression were significantly higher in expansive growth lesion (eg, papillary or local invasive lesion, metastatic colonization lesion) and significantly lower in diffuse infiltrative lesion of muscle or stroma of bladder. CONCLUSIONS: Our results revealed TMEM2 expression of bladder tumor is changed by inducing EMT-MET process. Source of Funding: none © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e226-e227 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mihoko Yoneyama* More articles by this author Tohru Yoneyama More articles by this author Hayato Yamamoto More articles by this author Yuki Tobisawa More articles by this author Shingo Hatakeyama More articles by this author Senji Hoshi More articles by this author Shigeru Tsuboi More articles by this author Tadashi Suzuki More articles by this author Chikara Ohyama More articles by this author Expand All Advertisement PDF downloadLoading ...

Isolation of Highly Migratory and Invasive Cells in Three-Dimensional Gels.

We developed a modified invasion assay in three-dimensional (3D) gels that permits isolation of invading cells as living cells, termed an invading cell-trapping (iCT) assay. A small cell strainer consisting of nylon mesh with pores of 40-µm square is used in this assay. A layer of gel composed of extracellular-matrix components is formed on each side of the nylon mesh, which permits cell migration or invasion from one gel layer to the other. At the end of the assay, the two gel layers are removed from the apparatus and easily separated from each other. Invading cells from the primary gel are trapped in the secondary gel, which maintains the morphology and other properties of the invasive cells in a 3D matrix. The cells that have invaded are observed and counted with a standard light microscope without cell staining. There is no need for a specialized microscope, imaging analysis software, or advanced cell-biological technical knowledge in this assay. This assay can also reduce measurement of nonspecific cell invasion by monitoring the upward invasion of cells. The viability of both invading and non-invading cells trapped in the gels can be assessed by typical colorimetric assays, if desired. This assessment characterizes the total number of cells (invading and non-invading cells) and the ratio of invading cells to total cells. By repeating the iCT assay, further enrichment of invasive and noninvasive cells can be attained. Thus, this assay improves comparative analyses between invasive and noninvasive cells. © 2020 by John Wiley & Sons, Inc. Basic Protocol 1: Measuring upward cell invasion into collagen gel Basic Protocol 2: Measuring cell invasion from Matrigel into collagen gel Basic Protocol 3: Isolation and enrichment of highly invasive cells.

Arg kinase mediates CXCL12/CXCR4-induced invadopodia formation and invasion of glioma cells

Compared with noninvasive tumor cells, glioma cells overexpress chemokine receptor type 4 (CXCR4), which exhibits significantly greater expression in invasive tumor cells than in noninvasive tumor cells. C-X-C motif chemokine ligand 12 (CXCL12, also known as stromal derived factor-1, SDF-1) and its cell surface receptor CXCR4 activate a signaling axis that induces the expression of membrane type-2 matrix metalloproteinase (MT2-MMP), which plays a pivotal role in the invasion and migration of various cancer cells; however, the specific mechanism involved in this is unclear. Recently, studies have shown that invadopodia can recruit and secrete related enzymes, such as matrix metalloproteinases (MMPs), to degrade the surrounding extracellular matrix (ECM), promoting the invasion and migration of tumor cells. Phosphorylated cortactin (pY421-cortactin) is required for the formation and maturation of invadopodia, but the upstream regulatory factors and kinases involved in phosphorylation have not been elucidated. In this study, we found that CXCL12/CXCR4 was capable of inducing glioma cell invadopodia formation, probably by regulating cortactin phosphorylation. The interaction of cortactin and Arg (also known as Abl-related nonreceptor tyrosine kinase, ABL2) in glioma cells was demonstrated. The silencing of Arg inhibited glioma cell invadopodia formation and invasion by blocking cortactin phosphorylation. Moreover, CXCL12 could not induce glioma cell invasion in Arg-knockdown glioma cells. Based on these results, it can be concluded that Arg mediates CXCL12/CXCR4-induced glioma cell invasion, and CXCL12/CXCR4 regulates invadopodia maturation through the Arg-cortactin pathway, which indicates that Arg could be a candidate therapeutic target to inhibit glioma cell invasion.

Different Mechanical Responses to Substrate Stiffness between Cancer Cells and Normal Cells

Metastatic cancer cells persistently interact with tumor microenvironment in every steps of their migrating processes. Understanding the effects of ECM on cancer cells are vital to decipher cancer cell invasion and metastasis. Thousands of molecules in focal adhesions are involved in the force transduction processes. Among them, talin acts as one of the most important participants. Conformational changes of talin caused by force are well researched by using single molecule force microscopies in the last decade. However, correlation between mechanical properties of the cancer cells and forces in focal adhesions in cancer metastasis are not fully understood. Here, we measured the viscoelastic properties of cancer cells on five different substrates and the force on talin in focal adhesions by using custom-made talin tension sensors. In order to find out the working patterns of metastatic cancer cells, we carried out the same measurements in human breast cells (MCF10A), non-invasive human breast cancer cells (MCF-7), and invasive human breast cancer cells (MDA-MB-231). By comparing the results, we found that invasive cancer cells can tune their mechanical properties, both viscoelastic properties and force on talin, accordingly when substrate stiffness are changed. Nonetheless, non-invasive cancer cells and normal cells lack this ability. Furthermore, membrane tether experiments conducted by atomic force microscopy also showed that strength of membrane tethers changed with substrate stiffness in MDA-MB-231 cells, not in MCF10A and MCF7 cells.

Hypoxic environment may enhance migration/penetration of endocrine resistant MCF7- derived breast cancer cells through monolayers of other non-invasive cancer cells in vitro

The response of cancer cells to hypoxic conditions found within the interior of a tumor mass is mediated through the hypoxia inducible factor (HIF) cascade and is thought to promote metastasis. However, given their distant proximity from blood vessels as compared to normoxic cells at the vascularised tumor periphery, it is uncertain if these cells can migrate through the tumor mass to gain access. Hypoxia was simulated by exposure to cobalt chloride or deferoxamine in normal (MCF10A) and cancerous [estrogen receptor (ER)−ve (pII), and ER +ve (YS1.2/ EII)] cells. In this report, HIF1α expression and localization was measured using western blotting, ELISA, and immunofluorescence, cell proliferation by MTT assay, motility and invasion by wound healing, live cell imaging, matrigel and co-culture in chambered slides. We found that the expression and nuclear translocation of HIF1α was significantly elevated by hypoxia, which inhibited cell proliferation, but significantly increased motility of pII cells and their penetration into and through a dense layer of adjacent EII cells, as well as their selective emergence out of a co-culture. These data suggest that endocrine resistant pII cancer cells, having undergone epithelial to mesenchymal transition are able to penetrate through other cell layers, with possible enhancement in response to hypoxia.

Microenvironment-induced TIMP2 loss by cancer-secreted exosomal miR-4443 promotes liver metastasis of breast cancer.

We aimed to investigate the role of exosomal miR-4443 in metastasis of breast cancer (BCa). In vitro wound-healing assay and transwell invasion assay were used to investigate effect of miR-4443 on BCa cells. Animal experiments were performed to confirm its effects in vivo. miR-4443 promotes the metastasis of BCa cells through downregulating tissue inhibitors of metalloproteinase 2 (TIMP2) and upregulating matrix metalloproteinases (MMPs). Highly invasive BCa cells have a higher expression of miR-4443 in both cells and exosomes. The exosomes derived from highly invasive BCa cells mainly gather in the primary tumor and liver. In vivo, overexpression of miR-4443 in noninvasive BCa cells induces liver metastasis, accompanied with downregulated TIMP2, and upregulated MMP-2 in both the primary tumor and liver. When we armed MCF-10A exosomes with miR-4443 inhibitors to treat mice bearing high-miR-4443 tumors, exosomes accumulated in the primary tumor, and liver following the upregulation of TIMP2 and downregulation of MMP2, and the metastasis was inhibited. Highly invasive BCa cells destroy natural barriers against metastasis by delivering exosomal miR-4443 to stromal cells of the primary tumor and impairing TIMP2, consequently activating MMP; circulating exosomal miR-4443 might promote BCa cells lodging in future metastatic sites through the similar mechanisms.

Discoidin Domain Receptor 1 functionally interacts with the IGF-I system in bladder cancer

Bladder cancer is one of the most common and aggressive cancers and, regardless of the treatment, often recurs and metastasizes. Thus, a better understanding of the mechanisms regulating urothelial tumorigenesis is critical for the design and implementation of rational therapeutic strategies. We previously discovered that the IGF-IR axis is critical for bladder cancer cell motility and invasion, suggesting a possible role in bladder cancer progression. However, IGF-IR depletion in metastatic bladder cancer cells only partially inhibited anchorage-independent growth. Significantly, metastatic bladder cancer cells have decreased IGF-IR levels but overexpressed the insulin receptor isoform A (IR-A), suggesting that the latter may play a more prevalent role than the IGF-IR in bladder tumor progression. The collagen receptor DDR1 cross-talks with both the IGF-IR and IR in breast cancer, and previous data suggest a role of DDR1 in bladder cancer. Here, we show that DDR1 is expressed in invasive and metastatic, but not in papillary, non-invasive bladder cancer cells. DDR1 is phosphorylated upon stimulation with IGF-I, IGF-II, and insulin, co-precipitates with the IGF-IR, and the IR-A and transient DDR1 depletion severely inhibits IGF-I-induced motility. We further demonstrate that DDR1 interacts with Pyk2 and non-muscle myosin IIA in ligands-dependent fashion, suggesting that it may link the IGF-IR and IR-A to the regulation of F-actin cytoskeleton dynamics. Similarly to the IGF-IR, DDR1 is upregulated in bladder cancer tissues compared to healthy tissue controls. Thus, our findings provide the first characterization of the molecular cross-talk between DDR1 and the IGF-I system and could lead to the identification of novel targets for therapeutic intervention in bladder cancer. Moreover, the expression profiles of IGF-IR, IR-A, DDR1, and downstream effectors could serve as a novel biomarker signature with diagnostic and prognostic significance.

Structure activity relationship analysis of antiproliferative cyclic C5-curcuminoids without DNA binding: Design, synthesis, lipophilicity and biological activity

The chemical susceptibility of the β-diketone linker between the two aromatic rings in the structure of curcumin to hydrolysis and metabolism has made it crucial to investigate structurally modified analogs of curcumin without such shortcomings. The synthesis of twenty cyclic C5-curcuminoids is described in this study in order to gain more insight into their anticancer structure-activity relationship (SAR). The design of their synthesis included four different cyclanones and five substituted aromatic aldehydes to form four, five-membered subgroups. These model compounds were evaluated in vitro for antiproliferative activity in an XTT cell viability assay against MCF-7 human non-invasive breast adenocarcinoma cancer cells and Jurkat human T lymphocyte leukemia cells in five different concentrations (10 nM, 100 nM, 1 μM, 10 μM and 20 μM). The majority of the compounds investigated have shown remarkable cytotoxicity with IC50 values in the range of 120 nM and 2 μM with very high relative toxicity values to curcumin. The SAR conclusions are drawn and summarized. A method was developed and applied in a TLC based experimental logP measurement, which is new for such C5-curcuminoids. The logP data and structural modifications have shown a strong correlation. The correlation of these experimental logP and the corresponding IC50 values of the model-compounds were calculated according to the Pearson and Kendall correlation coefficient and showed weak concordance. The physicochemical behaviors of the majority of these compounds are in good accordance with Lipinski’s rule. The most promising compound is 7a, which is the most active (IC50 = 0.12–0.32 μM), most potent (80 times of curcumin) with the lowest lipophilicity (experimental logP = 3.22) which is important also from a pharmacokinetic point of view. The analysis of experimental logP and computed ClogP values have revealed good agreement. These cyclic C5-curcuminoids in contrast to curcumin do not bind to natural DNA based on their CD spectra.

Mammary SLAMF3 Regulates Store-Operated Ca2+ Entry and Migration Through STIM1 in Breast Cancer Cells and Cell Lines

Abstract: Store Operated Calcium Entry (SOCE) is the main route for calcium entry in breast cells. After it’s activation by STromal Interaction Molecule (STIM) during endoplasmic reticulum store depletion, membrane channels ORAI are the main actors of this cell calcium entry. STIM, ORAI and SOCE alterations might contribute to Breast Cancer (BC) carcinogenesis. Recently, we reported the tumor suppressor role of Signaling Lymphocytic Activation Molecule Family member 3 (SLAMF3) on HepatoCellular Carcinoma (HCC) progression. SLAMF3 has been shown to regulate the activity of immune cells by modulating the calcium influx. In this report, we aimed at exploring the role of SLAMF3 in regulating SOCE and migration of BC cells. We quantified and compared the expression of SLAMF3 and STIM1 by quantitative RT-PCR in tumor and healthy resections of 14 patients followed at the University Hospital of Amiens. The expressions of SLAMF3 and STIM1 were also quantified and compared in non-invasive T47D and invasive MDA-MB-231 cell lines by quantitative RT-PCR, Western blot and flow cytometry. We determined the Ca2+ basal entry as well as SOCE by Mn2+ quenching and calcium imaging, respectively, in T47D and MDA-MB-231 cells overexpressing SLAMF3 ectopically. The cell proliferation and migration/invasion were investigated by MTT, wound healing assay and Boyden chambers tests, respectively. First, we report the expression of SLAMF3 in mammary epithelial cells. We highlight the complete loss of SLAMF3 expression in invasive BC cell lines compared to non-invasive cells. In addition, we show that the forced expression of SLAMF3 in invasive cells down-regulate specifically the STIM1 expression in invasive compared to non-invasive mammary cell lines. Interestingly, an inverse correlation is observed between the low expression of SLAMF3 and the high expression of STIM1 in primary human BC tissues. Our results indicate that SLAMF3 reduces SOCE and therefore restricts BC cell migration by decreasing STIM1 expression. Therefore, SLAMF3 might be used as a predictive marker of BC evolution and aggressiveness.

High-resolution imaging mass spectrometry combined with transcriptomic analysis identified a link between fatty acid composition of phosphatidylinositols and the immune checkpoint pathway at the primary tumour site of breast cancer

BackgroundThe fatty acid (FA) composition of phosphatidylinositols (PIs) is tightly regulated in mammalian tissue since its disruption impairs normal cellular functions. We previously found its significant alteration in breast cancer by using matrix-assisted laser desorption and ionisation imaging mass spectrometry (MALDI-IMS).MethodsWe visualised the histological distribution of PIs containing different FAs in 65 primary breast cancer tissues using MALDI-IMS and investigated its association with clinicopathological features and gene expression profiles.ResultsNormal ductal cells (n = 7) predominantly accumulated a PI containing polyunsaturated FA (PI-PUFA), PI(18:0/20:4). PI(18:0/20:4) was replaced by PIs containing monounsaturated FA (PIs-MUFA) in all non-invasive cancer cells (n = 12). While 54% of invasive cancer cells (n = 27) also accumulated PIs-MUFA, 46% of invasive cancer cells (n = 23) accumulated the PIs-PUFA, PI(18:0/20:3) and PI(18:0/20:4). The accumulation of PI(18:0/20:3) was associated with higher incidence of lymph node metastasis and activation of the PD-1-related immune checkpoint pathway. Fatty acid-binding protein 7 was identified as a putative molecule controlling PI composition.ConclusionsMALDI-IMS identified PI composition associated with invasion and nodal metastasis of breast cancer. The accumulation of PI(18:0/20:3) could affect the PD-1-related immune checkpoint pathway, although its precise mechanism should be further validated.

Bimodal Molecule as NIR-CT Contrast Agent for Hepatoma Specific Imaging.

With currently available molecular imaging techniques, hepatocellular carcinoma (HCC), a liver cancer with high mortality rates and poor treatment responses, is mostly diagnosed at its late stage. This is largely due to the lack of highly sensitive contrast agents with high liver specificity. Herein, we report a novel bimodal contrast agent molecule CNCI-1 for the effective detection of HCC at its early stage both in vitro and in vivo. The agent has high liver specificity with effective X-ray computed tomography (CT)/near-infrared (NIR) imaging functions. It has been successfully applied to in vivo NIR imaging with high sensitivity and high selectivity to the HCC region of the HepG2 tumor-xenografted mice model and LM3 orthotopic hepatoma mice model. Moreover, the agent was found to be noninvasive and hepatocarcinoma cells preferential. Furthermore, it also enhanced the tumor imaging by revealing the blood vessels nearby for the CT image acquisition in the VX2 orthotopic hepatoma rabbit model. Our design strategy provides a new avenue to develop the medical relevant bimodal contrast agents for diagnosis of HCC at its early stage.

Tracking metabolic dynamics of apoptosis with high-speed two-photon fluorescence lifetime imaging microscopy.

Programmed cell death, or apoptosis, is an essential process in development and homeostasis, and disruptions in associated pathways are responsible for a wide variety of diseases such as cancer, developmental abnormalities, and Alzheimer's disease. On the other hand, cell death, in many cases, is the desired outcome of therapeutic treatments targeting diseases such as cancer. Recently, metabolic imaging based on two-photon fluorescence microscopy has been developed and shown to be highly sensitive to certain cell death processes, most notably apoptosis, thus having the potential as an advanced label-free screening tool. However, the typically low acquisition rates of this imaging technique have resulted in a limited throughput approach, allowing only a small population of cells to be tracked at well-separated time points. To address this limitation, a high-speed two-photon fluorescence lifetime imaging microscopy (2P-FLIM) platform capable of video-rate imaging is applied to study and further characterize the metabolic dynamics associated with cell death. Building upon previous work demonstrating the capabilities of this system, this microscope is utilized to study rapid metabolic changes during cell death induction, such as dose-dependency of metabolic response, response in invasive vs. noninvasive cancer cells, and response in an apoptosis-resistant cell line, which is further shown to undergo autophagy in response to toxic stimuli. Results from these experiments show that the early apoptosis-related metabolic dynamics are strongly correlated with important cellular parameters including responsiveness to apoptosis-inducing stimuli. The high speed and sensitivity of the presented imaging approach enables new investigations into this highly dynamic and complex process.

ANGI-02. GENOME-WIDE shRNA SCREEN IDENTIFIES CANDIDATE GENES DRIVING GLIOBLASTOMA INVASION

Abstract BACKGROUND A major hallmark of glioblastoma (GBM) is its invasive capacity, contributing to its aggressive behaviour. Invasive cells cannot be easily removed by surgery or irradiation and eventually result in lethal recurrence. A better understanding of the invasion process and the key molecular players underlying the invasive potential of GBM may lead to the identification of new therapeutic targets for GBM patients. MATERIAL AND METHODS To identify candidate genes responsible for invasion, a genome-wide shRNA screen was performed in patient-derived GBM cultures. The most promising candidate was validated in in vitro invasion assays, ex vivo brain slice cultures and in vivo orthotopic xenografts in mice. Gene knockdown in invasive GBM cells was compared with overexpression in non-invasive cells. RNAseq of knockdown cells, along with the generation of deletion constructs were applied to uncover the mechanisms regulating invasion. RESULTS A zinc-finger domain containing protein was identified as an invasion essential candidate gene. Knockdown of this gene confirmed a strong impact on invasion in highly invasive GBM cells. In contrast, gene overexpression switched non-invasive GBM cells to an invasive phenotype. Deletion of one or both zinc-finger motifs decreased invasion indicating that both are essential for regulating invasion. Mutation of the nuclear localisation signal resulted in retention of the protein in the cytoplasm and loss of the invasion phenotype demonstrating that the protein activity is required in the nucleus. Gene expression analyses revealed that invasion-related genes are significantly regulated by the candidate gene once it is localized in the nucleus. CONCLUSION We identified a zinc-finger containing protein as a novel driver of GBM invasion, presumably through transcription factor activity resulting in the induction of an invasive transcriptional program. This protein and its downstream pathway may represent novel promising targets to overcome invasive capacities in GBM.

Calcitonin induces stem cell-like phenotype in prostate cancer cells.

Stem cell-like-cancer cells are key drivers of tumor growth, metastasis, and relapse of cancer following remission. Prostate stem cell-like cancer cells isolated from human prostate cancer (PC) biopsies express CD44+/α2β1 hi/CD133+ cell surface markers and can self-renew in vitro. Expression of calcitonin (CT) and its receptor (CTR) is frequently elevated in PCs and activation of CT-CTR axis in non-invasive PC cells induces an invasive phenotype. We investigated whether CT-CTR autocrine axis induces stem cell-like phenotype in two PC cell lines. CT-CTR axis in these cell lines was activated by enforced expression of CTR. The cells were then examined for the changes in the expression of CD44 and CD133, collagen adherence, tumorigenic, metastatic and repopulating characteristics. The activation of CT-CTR axis led to a large increase in adherence to collagen and a remarkable increase of CD44 and CD133 in PC-3 and LNCaP cells. This was accompanied by a strong increase in tumorigenic, metastatic and repopulation properties of PC cells. However, the mutation of CTR-C PDZ-binding site in CTR almost abolished CTR-mediated increases in stem cell-like characteristics of PC cells. These results support an important role for CT-CTR axis in the progression of PC from localized cancer to an aggressive form, and a majority of proinvasive CTR actions may be mediated through its interaction with its partner protein at the PDZ-binding site. These results suggest that CT/CTR can serve as a valuable target to prevent the generation of stem-like PC cells.

Inhibition of CYR61-S100A4 Axis Limits Breast Cancer Invasion.

Background and Objective: Matricellular proteins modulate the micro environment of tumors and are recognized to contribute to tumor cell invasion and dissemination. The cysteine-rich angiogenic inducer 61 (CYR61) is upregulated in mesenchymal transformed and invasive breast cancer cells. CYR61 correlates with poor prognosis of breast cancer patients. The signaling mechanism that causes invasive properties of cancer cells regarding to epithelial-mesenchymal transition (EMT) needs further research. In this study, we investigated the signaling mechanism, which is responsible for reduced cell invasion after suppression of CYR61 in mesenchymal transformed breast cancer cells and in triple negative breast cancer cells.Methods: We addressed this issue by generating a mesenchymal transformed breast cancer cell line using prolonged mammosphere cultivation. Western blotting and quantitative PCR were used to analyze gene expression alterations. Transient gene silencing was conducted using RNA interference. Proliferation was assessed using AlamarBlue assay. Invasiveness was analyzed using 2D and 3D invasion assays. Immune-histochemical analysis of patient tissue samples was performed to examine the prognostic value of CYR61 expression.Results: In this study, we investigated whether CYR61 could be used as therapeutic target and prognostic marker for invasive breast cancer. We discovered an interaction of CYR61 with metastasis-associated protein S100A4. Suppression of CYR61 by RNA interference reduced the expression of S100A4 dependent on ERK1/2 activity regulation. Non-invasive breast cancer cells became invasive due to extracellular CYR61 supplement. Immune-histochemical analysis of 239 patient tissue samples revealed a correlation of higher CYR61 and S100A4 expression with invasive breast cancer and metastasis.Conclusion: Our data suggest that suppression of CYR61 impedes the formation of an invasive cancer cell phenotype by reducing ERK1/2 phosphorylation thereby suppressing S100A4. These findings identify mechanisms by which CYR61 suppresses cell invasion and suggest it to be a potential therapeutic target and prognostic marker for invasive breast cancer and metastasis.

CD133 in Breast Cancer Cells: More than a Stem Cell Marker.

Initially correlated with hematopoietic precursors, the surface expression of CD133 was also found in epithelial and nonepithelial cells from adult tissues in which it has been associated with a number of biological events. CD133 is expressed in solid tumors as well, including breast cancer, in which most of the studies have been focused on its use as a surface marker for the detection of cells with stem-like properties (i.e., cancer stem cells (CSCs)). Differently with other solid tumors, very limited and in part controversial are the information about the significance of CD133 in breast cancer, the most common malignancy among women in industrialized countries. In this review, we summarize the latest findings about the implication of CD133 in breast tumors, highlighting its role in tumor cells with a triple negative phenotype in which it directly regulates the expression of proteins involved in metastasis and drug resistance. We provide updates about the prognostic role of CD133, underlining its value as an indicator of increased malignancy of both noninvasive and invasive breast tumor cells. The molecular mechanisms at the basis of the regulation of CD133 levels in breast tumors have also been reviewed, highlighting experimental strategies capable to restrain its level that could be taken into account to reduce malignancy and/or to prevent the progression of breast tumors.

P11.26 Genome-wide shRNA screen identifies candidate genes driving glioblastoma invasion

Abstract BACKGROUND A major hallmark of glioblastoma (GBM) is its highly invasive capacity, contributing to its aggressive behaviour. Since invasive cells cannot be easily removed by surgery or irradiation, they are left behind and eventually result in lethal recurrence. Therefore, a better understanding of the invasion process and of the key molecular players underlying the invasive capacities of GBM may lead to the identification of new therapeutic targets for GBM patients. MATERIAL AND METHODS To identify candidate genes responsible for invasion, a genome-wide shRNA screen was performed in patient-derived GBM sphere cultures. The phenotype of the most promising candidate was validated in in vitro invasion assays, ex vivo brain slice cultures and in vivo orthotopic xenografts in mice. Gene knockdown in invasive GBM cell lines was compared with overexpression in non-invasive cells. RNA sequencing of knockdown cells, along with the generation of deletion constructs were applied to uncover the mechanisms regulating invasion. RESULTS Through a whole genome shRNA screen, a zinc-finger containing protein was identified as an invasion essential candidate gene. Knockdown of this gene confirmed a strong decrease in invasion capacity in two highly invasive GBM cell lines. In contrast, gene overexpression switched non-invasive GBM cells to an invasive phenotype. Deletion of either one or both zinc-finger motifs led to decreased invasion indicating that the two zinc-finger motifs are essential for regulating invasion. Mutation of the nuclear localisation signal resulted in retention of the protein in the cytoplasm and loss of the invasion phenotype demonstrating that the protein activity is required in the nucleus. Gene expression analyses revealed that invasion-related genes are significantly regulated by the candidate gene once it is localized in the nucleus. CONCLUSION We identified a zinc-finger containing protein as a novel driver of GBM invasion, presumably through a transcription factor activity resulting in the induction of an invasive transcriptional program. This protein and its downstream pathway may represent a novel promising target to overcome invasive capacities in GBM.

P11.57 A 3D brain organoid coculture system delineates the invasive cell components in glioblastoma

Abstract BACKGROUND Glioblastoma (GBM) cell infiltration into the surrounding normal brain tissue where the blood brain barrier is intact, represents a major problem for clinical management and therapy. There is a vital need to understand the molecular mechanism that drives tumor cell invasion into the surrounding brain. We have previously developed a 3D coculture model where mature brain organoids are confronted with patient-derived glioblastoma stem-like cells (GSCs). In such a coculture system, single cell invasion into the normal brain tissue can be studied in detail. Here, we first describe in detail, by RNA-seq and proteomics, the differentiation of various neural cell lineages into mature brain organoids as well as their cellular organization. By real-time confocal microscopy and imaging analyses we also determine the speed of tumor cell invasion into the brain. Finally, we used this coculture system to delineate in detail the cellular heterogeneity within the invasive compartment and their gene expression. MATERIAL AND METHODS Immunohistochemistry and immunofluorescence were used to determine the expression and distribution of mature neurons, astrocytes, oligodendrocytes, and microglia within the brain organoids. Proteomics and RNA-seq were used to determine brain development ex-vivo. To assess the clonal composition of the GBM-invasive compartment, we used cellular (RGB) barcoding technology. By advanced imaging, we tracked in real time the invasion of barcoded cells into the brain organoids. Finally, we isolated invasive cells and non-invasive cells from our coculture system and used single cell sequencing to analyze their gene expression profiles and molecular phenotypes. RESULTS Immunohistochemistry and immunofluorescence showed that brain organoids, after 21 days of differentiation, display a highly cellular and structural organization. RNA-seq and proteomics, performed at different time points of organoid differentiation, revealed that the brain organoids develop into mature brain structures after 21 days as verified by a comparative analysis to normal rat brain development in vivo. Imaging analyses showed that multiple clones within the GBMs have the capacity to invade into the brain tissue with an average speed of ~ 20 μm/h. RNA-sec analysis of the invasive compartment revealed a strong up-regulation of genes and pathways associated with anaerobic respiration (glycolysis). CONCLUSION We describe a highly standardized brain organoid coculture system that can be used to delineate GBM invasion ex-vivo. We demonstrate that this platform can be used to unravel the mechanisms that drive GBM invasion into the normal brain.

Golgi phosphoprotein 3 (GOLPH3) promotes endometrial carcinoma cell invasion and migration by regulating the epithelial-mesenchymal transition.

BACKGROUND: Golgi phosphoprotein 3 (GOLPH3) is a novel oncogene overexpressed in several human cancers, but specific contributions to endometrial carcinoma (EC) have not been examined. The aims of this study were to evaluate the GOLPH3 expression in EC and investigate its functions in EC cell proliferation, migration, and survival.METHODS: The expression levels of GOLPH3 in EC patient samples and EC cell lines (HEC-1A, KLE, RL95-2, and Ishikawa) were examined using qRT-PCR, western blotting and immunohistochemistry. Further, EC cell lines with either ectopic GOLPH3 overexpression or knockdown were established, and the effects on proliferation, apoptosis, invasion, and migration were investigated in vitro using cell viability and transwell assays and in mice following cell injection.RESULTS: Compared to adjacent non-cancerous tissues, expression of GOLPH3 was significantly upregulated in EC tissues ( 0.05), and the expression level of GOPLPH3 was related to the grade of the tumor ( 0.05). The expression of GOLPH3 was also higher in all four EC cell lines than endometrial stromal cells (ESCs) ( 0.05). Moreover, GOLPH3 expression was greater in EC cell lines with high invasive capacity than in non-invasive EC cells ( 0.05). Knockdown of GOLPH3 inhibited EC cell proliferation and increased cell apoptosis in vitro. Further, knockdown of GOLPH3 also inhibited EC cell invasion and migration in vitro and in vivo by regulating the epithelial-mesenchymal transition (EMT). Conversely, GOLPH3 overexpression promoted proliferation and migration.CONCLUSIONS: The present study provides evidence that GOLPH3 promotes EMT and metastasis of EC cells and predicts the risk of EC progression, highlighting its potential as a therapeutic target for this malignancy.

Guanylate binding protein 1 (GBP-1) promotes cell motility and invasiveness of lung adenocarcinoma

Previously, we identified molecules involved in human invasive lung adenocarcinoma, and guanylate-binding protein 1 (GBP-1) was selected for further analysis. RT-PCR of normal lung and invasive lung adenocarcinoma tissue samples showed that the relative GBP-1 expression levels normalized to GAPDH for invasive lung adenocarcinoma were three-fold higher than those for normal lung samples (P < 0.05). GBP-1 gene and protein expression levels were also higher in mesenchymal-like than in epithelial-like lung adenocarcinoma cell lines. To determine whether GBP-1 participates in lung adenocarcinoma invasion, we performed migration and wound healing assays using RERF-LC-OK cells transfected with various siRNAs. The relative migration of transfected GBP1-siRNA1 and GBP1-siRNA2 cells was significantly lower than that of transfected control-siRNA cells. The relative wound healing capacities 6 and 12 h after cells transfected with GBP1-siRNA1 and GBP1-siRNA2 were scratched were significantly lower than those of the control-siRNA cells. Immunohistochemistry of 80 patients with Stage I lung adenocarcinoma revealed that non-invasive cells were GBP-1 negative in all cases. Invasive cells were GBP-1 positive in 10 cases (12.5%) and GBP-1 negative in 70 cases (87.5%). Lymphatic-vascular invasion was positive in 20 patients (25%) and positively correlated with GBP-1 expression (P < 0.05). In conclusion, GBP-1 may enhance lung adenocarcinoma invasiveness by promoting cell motility, and control of GBP-1 expression has the potential to contribute to the development of new therapeutic strategies for lung adenocarcinoma.