Metastatic Potential Of Cancer Cells Research Articles

GALNT8 suppresses breast cancer cell metastasis potential by regulating EGFR O-GalNAcylation

Breast cancer represents the most lethal malignancy that threatens the health of females. Metastasis is the fatal hallmark of breast cancer, and current effective therapeutic targets of metastasis are still lacking. Aberrant O-GalNAcylation, which is attributed to alteration of polypeptide N-acetylgalactosaminyl transferases (GALNTs), has been implicated in cancer metastasis. However, GALNTs that drive metastasis in breast cancer and their underlying mechanisms are largely unclear. In the present study, a negative correlation between GALNT8 and the prognosis of breast cancer patients was observed in multiple groups of Gene Expression Omnibus (GEO) datasets. We then constructed a stable GALNT8 knockdown MCF7 cell line and performed transcriptome analysis using RNA sequencing, which revealed that the expression of multiple migration-related genes was changed. GALNT8 was identified as a regulator of epithelial-mesenchymal transition (EMT) markers, including E-cadherin, N-cadherin, ZO-1 and vimentin. Moreover, loss- and gain-of-function GALNT8 assays demonstrated that this glycosyltransferase inhibited the metastatic potential of breast cancer cells. Interestingly, the O-GalNAcylation of EGFR, which is the key factor related to the metastasis cascade, was impacted by GALNT8. Furthermore, our results suggested that the GALNT8-mediated O-GalNAcylation led to the suppression of the EGFR signaling pathway and metastatic potential in breast cancer cells. These results suggested that GALNT8 acts as a tumor suppressor, represses tumor metastasis and inhibits the EMT process through the EGFR signaling pathway. This finding may provide insight into the mechanism by which aberrant O-glycosylation modulates breast cancer metastasis.

Confined Cell Migration and Asymmetric Hydraulic Environments to Evaluate the Metastatic Potential of Cancer Cells.

Metastasis, a hallmark of cancer development, is also the leading reason for most cancer-related deaths. Furthermore, cancer cells are highly adaptable to micro-environments and can migrate along pre-existing channel-like tracks of anatomical structures. However, more representative three-dimensional models are required to reproduce the heterogeneity of metastatic cell migration in vivo to further understand the metastasis mechanism and develop novel therapeutic strategies against it. Here, we designed and fabricated different microfluidic-based devices that recreate confined migration and diverse environments with asymmetric hydraulic resistances. Our results show different migratory potential between metastatic and nonmetastatic cancer cells in confined environments. Moreover, although nonmetastatic cells have not been tested against barotaxis due to their low migration capacity, metastatic cells present an enhanced preference to migrate through the lowest resistance path, being sensitive to barotaxis. This device, approaching the study of metastasis capability based on confined cell migration and barotactic cell decisions, may pave the way for the implementation of such technology to determine and screen the metastatic potential of certain cancer cells.

Nuclear Respiratory Factor 1 Overexpression Inhibits Proliferation and Migration of PC3 Prostate Cancer Cells.

The role of nuclear respiratory factor 1 (NRF1) on the prostate cancer progression is controversial. We aimed to investigate the effect of NRF1 overexpression on the metastasis potential of PC3 prostate cancer cells and the associated molecular mechanisms. Cell survival, migration capacity, mitochondrial biogenesis, the expression of TGF-β signaling and EMT markers were examined after overexpression and silencing of NRF1 in PC3 cells. We found that NRF1-overexpressing cells exhibited a decreased cell viability and proliferation ability as well as a reduced migration capacity compared to control cells. Moreover, ectopic expression of NRF1 increased the mitochondrial biogenesis and inhibited the EMT characteristics, including a decrease in the mesenchymal marker, α-SMA and an increase in the epithelial cell marker, E-cadherin. We also demonstrated that overexpression of NRF1 suppressed the expression of TGF-β signaling in PC3 cells. As expected, silencing of NRF1 reversed the abovementioned effects. This study demonstrated that upregulation of NRF1 holds the potential to inhibit the metastasis of prostate cancer, possibly through an elevation of mitochondrial biogenesis and the subsequent repression of TGF-β-associated EMT. Therapeutic avenues that increase NRF1 expression may serve as an adjunct to conventional treatments of prostate cancer.

Metadherin-mediated mechanisms in human malignancies.

Metadherin (MTDH) has been recognized as a novel protein that is critical for the progression of multiple types of human malignancies. Studies have reported that MTDH enhances the metastatic potential of cancer cells by regulating multiple signaling pathways. miRNAs and various tumor-related proteins have been shown to interact with MTDH, making it a potential therapeutic target as well as a biomarker in human malignancies. MTDH plays a critical role in inflammation, angiogenesis, hypoxia, epithelial-mesenchymal transition and autophagy. In this review, we present the function and mechanisms of MTDH for cancer initiation and progression.

Therapeutic Potential of Pharmacological Targeting NLRP3 Inflammasome Complex in Cancer Using Inhibition of NLRP3 Inflammasome in Tumor Microenvironment Leads to Suppression of Metastatic Potential of Cancer Cells

Thanks to work by researchers at the California South University (CSU) Cancer Research Institute (CRI), they may soon have new tools to treat melanoma and other cancers. In an article published last month, members of the Cancer Research Institute (CRI) introduced an intracellular complex. Involved in melanoma-mediated inflammation and leads to tumor growth and progression. The researchers found that by inhibiting NLRP3, they could reduce inflammation and tumor spread. Keywords: Cancer; Cells; Tissues, Tumors; Prevention, Prognosis; Diagnosis; Imaging; Screening; Treatment; Management

LINC01605, regulated by the EP300-SMYD2 complex, potentiates the binding between METTL3 and SPTBN2 in colorectal cancer

BackgroundColorectal cancer (CC) is one of the major contributors to tumor-related death worldwide, and its main cause of death is distant metastasis. Dysregulation of long non-coding RNA (lncRNA) LINC01605 has been implicated in CC. However, its role in metastasis of CC remains elusive. The goal of the study is to uncover the biological function and molecular mechanism of LINC01605 in CC.MethodsThe differentially expressed lncRNAs were first screened from GSE97300, GSE84983, GSE110715, GSE70880, and GSE75970 microarrays. The correlation between the expression of LINC01605 and the clinical phenotypes of enrolled CC patients (n = 134) was subsequently analyzed. The upstream and downstream regulatory mechanisms of LINC01605 in CC were identified through bioinformatics and RNA-seq analyses. Finally, the effects of related factors on CC cell growth and metastasis were confirmed through functional validation experiments.ResultsLINC01605, significantly highly expressed in CC, was a prognostic factor for patients with CC. Functional experiments revealed that LINC01605 knockdown inhibited the proliferatory and metastatic potential of CC cells in vitro and in vivo. Moreover, LINC01605 was regulated by SMYD2-EP300-mediated modifications of histone H3K4me3 as well as H3K27ac. LINC01605 was found to bind to METTL3 and promote the m6A modification of SPTBN2 mRNA, thereby facilitating the translation of SPTBN2.ConclusionsOverexpression of LINC01605, regulated by SMYD2-EP300-mediated H3K27ac and H3K4me3 modifications, bound to METTL3 protein to promote m6A modification of SPTBN2 mRNA, leading to the development of CC.

MiR-200 deficiency promotes lung cancer metastasis by activating Notch signaling in cancer-associated fibroblasts.

Lung adenocarcinoma, the most prevalent lung cancer subtype, is characterized by its high propensity to metastasize. Despite the importance of metastasis in lung cancer mortality, its underlying cellular and molecular mechanisms remain largely elusive. Here, we identified miR-200 miRNAs as potent suppressors for lung adenocarcinoma metastasis. miR-200 expression is specifically repressed in mouse metastatic lung adenocarcinomas, and miR-200 decrease strongly correlates with poor patient survival. Consistently, deletion of mir-200c/141 in the KrasLSL-G12D/+ ; Trp53flox/flox lung adenocarcinoma mouse model significantly promoted metastasis, generating a desmoplastic tumor stroma highly reminiscent of metastatic human lung cancer. miR-200 deficiency in lung cancer cells promotes the proliferation and activation of adjacent cancer-associated fibroblasts (CAFs), which in turn elevates the metastatic potential of cancer cells. miR-200 regulates the functional interaction between cancer cells and CAFs, at least in part, by targeting Notch ligand Jagged1 and Jagged2 in cancer cells and inducing Notch activation in adjacent CAFs. Hence, the interaction between cancer cells and CAFs constitutes an essential mechanism to promote metastatic potential.

Abstract 2690: Therapeutic browning of white adipose tissue in the tumor microenvironment to inhibit breast cancer progression

Abstract Background and Aim: The growth and metastatic potential of cancer cells is regulated by the surrounding tumor microenvironment composed of a variety of cells including endothelial cells, fibroblasts, and adipose cells that promote tumor cell growth and invasion. There are two types of adipose tissue within the body. Brown adipocytes (BAT) contains uncoupling protein 1 (UCP1), which burns energy through adaptive thermogenesis. White adipocytes (WAT), which is the most prominent cell type in the breast, stores energy in the form of lipids. White adipocytes have the ability to secrete cytokines, growth factors, and hormones, providing a suitable microenvironment for breast tumor growth and progression. Identifying the mechanism through which adipocytes promote breast tumor progression will allow for the development of novel therapeutic interventions to inhibit adipocyte-breast cancer cell crosstalk during early stages of breast carcinogenesis. Furthermore, development of treatments that target cells within the tumor microenvironment, such as adipose cells, will potentially inhibit primary tumor growth as well as prevent metastatic disease, and could provide a treatment option for breast cancers. Methods: Functional assays including matrigel invasion, transwell migration and growth assays were conducted. Browning of white adipocyte was achieved by the addition of bioactive compounds such as BITC and Honokiol. Results: First, we explored the functional impact of WAT on breast cancer cells and observed that co-culture of WAT and breast cancer cells significantly increases the growth, clonogenicity, invasion and migration potential of breast cancer cells. In addition, breast cancer cells with epithelial-like morphology exhibit an acquisition of mesenchymal-like morphology indicating epithelial-to-mesenchymal conversion. To query the existence of a crosstalk between breast cancer cells and WAT, we examined the secretome of WATs and WATs-co-cultured with breast cancer cells (termed CA-WAT). We observed that CA-WAT exhibit increased levels of pro-inflammatory cytokines (IL-6, MCP, and PAI). Furthermore, we examined if WAT can be converted to BAT using bioactive strategies. We found that successful browning of WAT can be achieved with BITC and Honokiol. The addition of bioactive compounds increases the expression of BAT marker genes (UCP1, PRDM16, EVOL3, COX7a, and CIDEA) in WAT. We discovered that browning of WAT not only abrogates the pro-cancer effects of WAT on breast cancer cells but it also successfully alters the secretome profile of WAT. Conclusion: Our study shows that the conversion of white adipocytes to brown adipocytes with the use of BITC and Honokiol may serve as a novel therapeutic option for altering the breast tumor microenvironment to inhibit the growth and metastatic potential of breast cancer cells. Citation Format: Nethaji Muniraj, Sumit Siddharth, Sheetal Parida, Marey Shriver, Arumugam Nagalingam, Dipali Sharma. Therapeutic browning of white adipose tissue in the tumor microenvironment to inhibit breast cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2690.

Abstract 1298: Designing novel small molecule inhibitors as possible targeted therapeutics to prevent breast cancer metastasis

Abstract Breast cancer is currently the second leading cause of cancer-related deaths and the most commonly diagnosed cancer among women in the Unites States. Localized breast cancer has a five-year survival rate of 99%, however the survival rate for patients with distant metastasis is 27%, despite improved screening and detection methods. Currently, there are few targeted therapies that specifically inhibit metastasis. Research performed by our lab and others has shown that inflammatory cytokines play a crucial role in promoting cancer growth and metastatic potential in cancer cells. While efforts have been made to develop FDA approved therapeutics for inflammatory cytokines, very few have successfully made it through clinical trials and several cytokines still lack effective clinical inhibitors. Our research has developed a stepwise approach towards designing and testing novel small molecule inhibitors (SMIs) against inflammatory cytokines. In silico computational screening of compound libraries towards specific inflammatory cytokines revealed potential molecules that interact with receptor binding regions and inhibit cytokine biological function. Top candidate inhibitors were analyzed for direct interaction with cytokines using differential scanning fluorimetry, fluorescent quenching, and Chemical Shift Pertubation NMR (CSP-NMR). Additionally, to quantitatively measure cytokine-receptor interference, a novel ligand-receptor binding assay was developed highlighting small molecule inhibitors that effectively prevent biological cytokine function. In vitro efficacy of the SMIs were analyzed by measuring inhibition of various signaling cascades activated by inflammatory cytokines using enzyme-linked immunosorbent assay (ELISA) and immunoblot assays. Inhibition of tumor cell proliferation, epithelial to mesenchymal transition (EMT), and cytokine-induced secretion of pro-tumorigenic molecules was also assessed. From these in silico and in vitro methods, SMI's are structurally modified with effective functional groups to increase efficacy of binding interaction and reduce toxicity for living systems. Finally, small molecule inhibitors that have been sufficiently tested for efficacy are then examined in vivo to evaluate toxicity and determine the maximum tolerated dose. SMI's that prove to be non-toxic are evaluated further in vivo by mouse mammary breast cancer models to analyze reduction of distant metastases. Our interdisciplinary team has designed, synthesized, and tested small molecule inhibitors (SMIs) to target inflammatory cytokines shown to promote metastasis in cancer with the long-term goal of understanding lethal breast cancer metastasis, as well as providing a novel FDA approved therapeutic for breast cancer patients. Citation Format: Cody L. Wolf, Clyde Pruett, Darren Lighter, Cooper McGrath, Amberlyn Nemeth, Joey Tuccinardi, Grace Coughlin, Samuel Randall, Joey Day, Matthew King, Lisa Warner, Don Warner, Cheryl L. Jorcyk. Designing novel small molecule inhibitors as possible targeted therapeutics to prevent breast cancer metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1298.

Silent information regulator 1 suppresses epithelial-to-mesenchymal transition in lung cancer cells via its regulation of mitochondria status

AimsSilent information regulator 1 (SIRT1) is a NAD+-dependent protein-modifying enzyme involved in regulating gene expression, DNA damage repair, cell metabolism, and mitochondrial functions. Given that it acts as both a tumor promoter and suppressor, the complex mechanisms underlying SIRT1 signaling in cancer remain controversial. Epithelial-to-mesenchymal transition (EMT) plays a key role in the progression of carcinogenesis and tumors metastasis. Studies have shown that mitochondrial defects are critical in EMT process, and SIRT1 is found to regulate the generation and energy metabolism of mitochondria. Here, we elucidate a novel mechanism by which SIRT1 affects EMT in lung cancer cells via its regulation on mitochondria. Main methodsSIRT1 signaling was detected in TGF-β1-induced EMT and was found to regulate mitochondria status, including mitochondrial biogenesis-related protein levels as detected by western blotting, mitochondrial structure observed by transmission electron microscopy, and respiratory functions analyzed by a respiration capacity assay. The effects of modulating SIRT1 expression on EMT and migration of lung cancer cells or normal cells were evaluated by in vitro and in vivo models. Key findingsWe found that the regulation of SIRT1 signaling on the biogenesis or functions of mitochondria was critical to EMT. Overexpression of SIRT1 reduced EMT or metastasis potential of lung cancer cells by improving the quantity and quality of mitochondria, whereas silencing SIRT1 promote EMT in cancer cells, even in normal cells by disturbing mitochondria status. SignificanceConsequently, SIRT1 is an attractive therapeutic target for reversing EMT or tumor metastasis.

Cancer cell metabolic plasticity in migration and metastasis.

Metabolic reprogramming is a hallmark of cancer metastasis in which cancer cells manipulate their metabolic profile to meet the dynamic energetic requirements of the tumor microenvironment. Though cancer cell proliferation and migration through the extracellular matrix are key steps of cancer progression, they are not necessarily fueled by the same metabolites and energy production pathways. The two main metabolic pathways cancer cells use to derive energy from glucose, glycolysis and oxidative phosphorylation, are preferentially and plastically utilized by cancer cells depending on both their intrinsic metabolic properties and their surrounding environment. Mechanical factors in the microenvironment, such as collagen density, pore size, and alignment, and biochemical factors, such as oxygen and glucose availability, have been shown to influence both cell migration and glucose metabolism. As cancer cells have been identified as preferentially utilizing glycolysis or oxidative phosphorylation based on heterogeneous intrinsic or extrinsic factors, the relationship between cancer cell metabolism and metastatic potential is of recent interest. Here, we review current in vitro and in vivo findings in the context of cancer cell metabolism during migration and metastasis and extrapolate potential clinical applications of this work that could aid in diagnosing and tracking cancer progression in vivo by monitoring metabolism. We also review current progress in the development of a variety of metabolically targeted anti-metastatic drugs, both in clinical trials and approved for distribution, and highlight potential routes for incorporating our recent understanding of metabolic plasticity into therapeutic directions. By further understanding cancer cell energy production pathways and metabolic plasticity, more effective and successful clinical imaging and therapeutics can be developed to diagnose, target, and inhibit metastasis.

Iron oxide-based enzyme mimic nanocomposite for dual-modality imaging guided chemical phototherapy and anti-tumor immunity against immune cold triple-negative breast cancer

Triple-negative breast cancer has few biomarkers to guide benefit from immunotherapy; furthermore, the biochemical features of the tumor microenvironment including acidosis, hypoxia, and high hydrogen peroxide concentrations, significantly modulate cancer cell metabolism and metastatic potential, and associate with bad outcomes from chemo-radiotherapy and surgery. Herein, a theranostic nanocomposite with a dual imaging modality and chemical phototherapeutic capacity has been used for breast cancer cell inhibition, which is developed to self-assemble superparamagnetic iron oxide nanocrystals and IR-780 iodides in one system. Due to the magnetic resonance and near-infrared Ⅱ fluorescence capacity, this nanocomposite serves as a contrast agent for the high-sensitivity, accurate cancer diagnosis and facilitates imaging-guided phototherapy. Furthermore, this nanocomposite not only performs dual enzyme-like activities in the tumor microenvironment, but also carries out the bioeffect of hyperthermia and oxidative stress, which could repolarize tumor-associated macrophages from the tumor-promoting M2 phenotype into the tumoricidal M1 phenotype, reduce the number of immunosuppressive cells, and execute immune activation. Through simultaneous chemical phototherapy and anti-tumor immunity, this iron oxide-based nanocomposite successfully suppresses tumor growth and metastasis, and has good biocompatibility in normal tissues and organs; thus, it might provide new insights into the development of a novel cancer therapy strategy.

Fibroblast Growth Factor Receptors (FGFRs) and Noncanonical Partners in Cancer Signaling.

Increasing evidence indicates that success of targeted therapies in the treatment of cancer is context-dependent and is influenced by a complex crosstalk between signaling pathways and between cell types in the tumor. The Fibroblast Growth Factor (FGF)/FGF receptor (FGFR) signaling axis highlights the importance of such context-dependent signaling in cancer. Aberrant FGFR signaling has been characterized in almost all cancer types, most commonly non-small cell lung cancer (NSCLC), breast cancer, glioblastoma, prostate cancer and gastrointestinal cancer. This occurs primarily through amplification and over-expression of FGFR1 and FGFR2 resulting in ligand-independent activation. Mutations and translocations of FGFR1-4 are also identified in cancer. Canonical FGF-FGFR signaling is tightly regulated by ligand-receptor combinations as well as direct interactions with the FGFR coreceptors heparan sulfate proteoglycans (HSPGs) and Klotho. Noncanonical FGFR signaling partners have been implicated in differential regulation of FGFR signaling. FGFR directly interacts with cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins, contributing to invasive and migratory properties of cancer cells, whereas interactions with other receptor tyrosine kinases (RTKs) regulate angiogenic, resistance to therapy, and metastatic potential of cancer cells. The diversity in FGFR signaling partners supports a role for FGFR signaling in cancer, independent of genetic aberration.

Lumican Inhibits In Vivo Melanoma Metastasis by Altering Matrix-Effectors and Invadopodia Markers.

It was reported that lumican inhibits the activity of metalloproteinase MMP-14 and melanoma cell migration in vitro and in vivo. Moreover, Snail triggers epithelial-to-mesenchymal transition and the metastatic potential of cancer cells. Therefore, the aim of this study was to examine the effect of lumican on Mock and Snail overexpressing melanoma B16F1 cells in vivo. Lung metastasis was analyzed after intravenous injections of Mock-B16F1 and Snail-B16F1 cells in Lum+/+ and Lum−/− mice. At day 14, mice were sacrificed, and lungs were collected. The number of lung metastatic nodules was significantly higher in mice injected with Snail-B16F1 cells as compared to mice injected with Mock-B16F1 cells confirming the pro-metastatic effect of Snail. This effect was stronger in Lum−/− mice as compared to Lum+/+, suggesting that endogenous lumican of wild-type mice significantly inhibits metastasis to lungs. Scanning electron and confocal microscopy investigations demonstrated that lumican inhibits the development of elongated cancer cell phenotypes which are known to develop invadopodia releasing MMPs. Moreover, lumican was shown to affect the expression of cyclin D1, cortactin, vinculin, hyaluronan synthase 2, heparanase, MMP-14 and the phosphorylation of FAK, AKT, p130 Cas and GSK3α/β. Altogether, these data demonstrated that lumican significantly inhibits lung metastasis in vivo, as well as cell invasion in vitro, suggesting that a lumican-based strategy targeting Snail-induced metastasis could be useful for melanoma treatment.

Non-Coding RNAs in Cancer Diagnosis and Therapy: Focus on Lung Cancer.

Simple SummaryResearchers have spent nearly two decades unraveling the roles of non-coding RNAs in cancer biology. In recent years, deep transcriptomic profiling of tissue and circulating non-coding RNAs in cancer patients have elucidated non-coding RNAs as potential biomarkers that can inform cancer diagnosis and prognosis. Clinical trials have also begun examining non-coding RNA-based drugs as adjuncts to traditional chemotherapeutics. Overall, our review is structured to provide an overview of non-coding RNAs in cancer biology, diagnostics, and therapeutics, focusing on lung cancer.Over the last several decades, clinical evaluation and treatment of lung cancers have largely improved with the classification of genetic drivers of the disease, such as EGFR, ALK, and ROS1. There are numerous regulatory factors that exert cellular control over key oncogenic pathways involved in lung cancers. In particular, non-coding RNAs (ncRNAs) have a diversity of regulatory roles in lung cancers such that they have been shown to be involved in inducing proliferation, suppressing apoptotic pathways, increasing metastatic potential of cancer cells, and acquiring drug resistance. The dysregulation of various ncRNAs in human cancers has prompted preclinical studies examining the therapeutic potential of restoring and/or inhibiting these ncRNAs. Furthermore, ncRNAs demonstrate tissue-specific expression in addition to high stability within biological fluids. This makes them excellent candidates as cancer biomarkers. This review aims to discuss the relevance of ncRNAs in cancer pathology, diagnosis, and therapy, with a focus on lung cancer.

Oxidized Phospholipids in Tumor Microenvironment Stimulate Tumor Metastasis via Regulation of Autophagy.

Oxidized phospholipids are well known to play physiological and pathological roles in regulating cellular homeostasis and disease progression. However, their role in cancer metastasis has not been entirely understood. In this study, effects of oxidized phosphatidylcholines such as 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) on epithelial-mesenchymal transition (EMT) and autophagy were determined in cancer cells by immunoblotting and confocal analysis. Metastasis was analyzed by a scratch wound assay and a transwell migration/invasion assay. The concentrations of POVPC and 1-palmitoyl-2-glutaroyl-sn-glycero-phosphocholine (PGPC) in tumor tissues obtained from patients were measured by LC-MS/MS analysis. POVPC induced EMT, resulting in increase of migration and invasion of human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF7). POVPC induced autophagic flux through AMPK-mTOR pathway. Pharmacological inhibition or siRNA knockdown of autophagy decreased migration and invasion of POVPC-treated HepG2 and MCF7 cells. POVPC and PGPC levels were greatly increased at stage II of patient-derived intrahepatic cholangiocarcinoma tissues. PGPC levels were higher in malignant breast tumor tissues than in adjacent nontumor tissues. The results show that oxidized phosphatidylcholines increase metastatic potential of cancer cells by promoting EMT, mediated through autophagy. These suggest the positive regulatory role of oxidized phospholipids accumulated in tumor microenvironment in the regulation of tumorigenesis and metastasis.

N6-methyladenosine modification of MALAT1 promotes metastasis via reshaping nuclear speckles.

N6-methyladenosine (m6A), one of the most prevalent RNA post-transcriptional modifications, is involved in numerous biological processes. In previous studies, the functions of m6A were typically identified by perturbing the activity of the methyltransferase complex. Here, we dissect the contribution of m6A to an individual-long noncoding RNA-metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). The mutant MALAT1 lacking m6A-motifs significantly suppressed the metastatic potential of cancer cells both invitro and invivo in mouse. Super-resolution imaging showed that the concatenated m6A residues on MALAT1 acted as a scaffold for recruiting YTH-domain-containing protein 1 (YTHDC1) to nuclear speckles. We further reveal that the recognition of MALAT1-m6A by YTHDC1 played a critical role in maintaining the composition and genomic binding sites of nuclear speckles, which regulate the expression of several key oncogenes. Furthermore, artificially tethering YTHDC1 onto m6A-deficient MALAT1 largely rescues the metastatic potential of cancer cells.

The action of hyaluronan in functional properties, morphology and expression of matrix effectors in mammary cancer cells depends on its molecular size.

Breast cancer constitutes a heterogeneous disease. The expression profiles of estrogen receptors (ERs), as well as the expression patterns of extracellular matrix (ECM) macromolecules, determine its development and progression. Hyaluronan (HA) is an ECM molecule that regulates breast cancer cells' properties in a molecular size-dependent way. Previous studies have shown that 200-kDa HA fragments modulate the functional properties, morphology, and expression of several matrix mediators of the highly metastatic ERα- /ERβ+ MDA-MB-231 cells. In order to evaluate the effects of HA fragments (<10, 30 and 200-kDa) in ERβ-suppressed breast cancer cells, the shERβ MDA-MB-231 cells were used. These cells are less aggressive when compared with MDA-MB-231 cells. To this end, the functional properties, the morphology, and the expression of the molecules associated with breast cancer cells metastatic potential were studied. Notably, both cell proliferation and invasion were significantly reduced after treatment with 200-kDa HA. Moreover, as assessed by scanning electron microscopy, 200-kDa HA affected cellular morphology, and as assessed by qPCR, upregulated the epithelial marker Ε-cadherin. The expression profiles of ECM mediators, such as HAS2, CD44, and MMP7, were also altered. On the other hand, cellular migration and the expression levels of syndecan-4 (SDC-4) were not significantly affected in contrast to our observations regarding MDA-MB-231 cells. These novel data demonstrate that the molecular size of the HA determines its effects on ERβ-suppressed breast cancer cells and that 200-kDa HA exhibits antiproliferative effects on these cells. A deeper understanding of this mechanism may contribute to the development of therapeutic strategies against breast cancer.

Therapeutic Strategies Against Cancer Stem Cells in Esophageal Carcinomas.

Cancer stem cells (CSCs) in esophageal cancer have a key role in tumor initiation, progression and therapy resistance. Novel therapeutic strategies to target CSCs are being tested, however, more in-depth research is necessary. Eradication of CSCs can result in successful therapeutic approaches against esophageal cancer. Recent evidence suggests that targeting signaling pathways, miRNA expression profiles and other properties of CSCs are important strategies for cancer therapy. Wnt/β-catenin, Notch, Hedgehog, Hippo and other pathways play crucial roles in proliferation, differentiation, and self-renewal of stem cells as well as of CSCs. All of these pathways have been implicated in the regulation of esophageal CSCs and are potential therapeutic targets. Interference with these pathways or their components using small molecules could have therapeutic benefits. Similarly, miRNAs are able to regulate gene expression in esophageal CSCs, so targeting self-renewal pathways with miRNA could be utilized to as a potential therapeutic option. Moreover, hypoxia plays critical roles in esophageal cancer metabolism, stem cell proliferation, maintaining aggressiveness and in regulating the metastatic potential of cancer cells, therefore, targeting hypoxia factors could also provide effective therapeutic modalities against esophageal CSCs. To conclude, additional study of CSCs in esophageal carcinoma could open promising therapeutic options in esophageal carcinomas by targeting hyper-activated signaling pathways, manipulating miRNA expression and hypoxia mechanisms in esophageal CSCs.

Abstract PS4-42: Kiss1, the kiss1 receptor (kiss1r) and the protein kinase c (pkc) family identifies patients with clinical outcome in clinical breast cancer

Abstract Background: Kiss1, also known as Kisspeptin-1 and metastin, is a protein coded by the KISS1 gene (1). The receptor for KISS1, KISS1R (also known as G-protein coupled receptor 54 or GPR54 is coded by the KISS1R gene. Kiss1 and Kiss1R have been indicated in a number of pathophysiological conditions, including metabolic and reproductive abnormalities and the protein complex has been well indicated in the development and progression of a number of solid cancers including the metastatic potential of cancer cells (1) and in clinical cancers including breast cancer (2). Here, the intracellular events associated with KISS1/KISS1R signalling have been explored, including focal adhesion kinase and phospholipase-C (PLC) pathways where we employed a protein kinase platform together with a clinical breast cohort in order to explore protein kinases that are involved in KISS1 signalling and the clinical significance. Methods: A protein kinase microarray (Kinexus850) was employed to detect the cellular kinase responses to exogenous Kisspeptin stimulation. Kiss1, Kiss1 receptor (KISS1R or GPR54) and the prospective members of the protein kinase C (PKC) family members were assessed for the expression in a Cardiff breast cancer cohort and were analysed against the pathological and clinical outcomes of the patients. Results. Using the Kinexus protein kinase platform, we identified that some key members of the protein kinase C family were upregulated in response to treatment with exogenous Kisspeptin. These members include Protein kinase C (PKC)-gamma, PKC-iota, PKC-zeta and PKC-delta, which are potential downsteam targets of KISS1/KISS1R. In our clinical cohort, KISS1 was significantly correlated with the expression levels of PKC-iota (p=0.01) and PKC-gamma (p&amp;lt;0.001). Similarly, KISS1 receptor (KISS1R) was also significantly correlated with both PKC-gamma and PKC-iota. Neither PKC-delta nor PKC-zeta showed a correlation with KISS1 and KISS1R in the clinical cohort. When KISS1, KISS1R, PKC-gamma and PKC-iota were collectively analysed against clinical outcome of the patients, the four molecules identified a subset of the patients who had all survived the ten year followup period (OS) and with no breast cancer related incidence (DFS). The subgroup consisted of all Her-2 negative tumours but with variable nodal and disease stages. Multivariate analyses indicate that the collective expression pattern of KISS1, KISS1R, PKC-gamma and PKC-iota is an independent prognostic factor for disease free survival in breast cancer patients. Discussion: Protein kinase C (PKC) family members, including PKC-gamma and PKC-iota, are important downstream intracellular events in response to KISS1/KISS1R activation. These protein kinase C members together with KISS1/KISS1R protein complex identify a subset of patients with breast cancer who have favourable prognosis.