Project description:I investigated the role of insulin receptor substrate 2 (IRS2) in small-intestinal neuroendocrine tumours (SI-NETs). Using SI-NET cell lines (STC-1 and Glu-tag), I found that IRS2 was significantly upregulated. IRS2 knockdown inhibited cellular proliferation, migration, and invasion, while its overexpression promoted these processes. For in vivo validation, I established stable IRS2-knockdown cell lines and performed xenograft experiments in nude mice. Transcriptomic profiling by RNA sequencing was conducted to identify downstream targets of IRS2 signaling.
Project description:Glioblastoma cells are characterized by a highly invasive behavior whose mechanisms are not yet understood. Using the wound healing and Boyden chamber assays we compared in the present study the migration and invasion abilities of 5 glioblastoma cell lines (DK-MG, GaMG, U87-MG, U373-MG, SNB19) differing in p53 and PTEN status. We also analyzed by Western blotting the expression of PTEN, p53, mTOR and several other marker proteins involved in cell adhesion, migration and invasion. Among 5 cell lines, GaMG cells exhibited the fastest rate of wound closure, whereas U87-MG cells showed the most rapid chemotactic migration in the Boyden chamber assay. In DK-MG and GaMG cells, F-actin mainly occurred in the numerous stress fibers spanning the cytoplasm, whereas U87-MG, U373-MG and SNB19 cells preferentially expressed F-actin in filopodia and lamellipodia. Moreover, the two glioblastoma lines mutated in both p53 and PTEN genes (U373-MG and SNB19) were found to exhibit the fastest invasion rates through the Matrigel matrix. Here, we performed a gene expression profiling of the five glioblastoma cell lines to examine the molecular framework of differences in invasive behavior to find possible targets for chemo- and radiation therapy.
Project description:Relative beta cell deficit and increased beta cell apoptosis are hallmarks of type 2 diabetes (T2D). The Insulin/Insulin Growth Factor (Igf) signaling pathway is an established regulator of beta cell survival and is found downregulated in human T2D islets. The Insulin Receptor Substrate 2 (Irs2) plays a central role in the coordination of this pathway in beta cells. Thus, Irs2 knockout mice (Irs2 -/-) exhibit increased beta cell apoptosis that leads to a progressive decline of beta cell mass and hyperglycaemia. In this study, we sought to determine whether the anti-diabetic compound sodium tungstate could prevent the onset of diabetes in Irs2 -/- mice. Oral administration of tungstate resulted in an overall improvement in whole-body glucose tolerance in Irs2 -/- mice which correlated with increased beta cell mass. Enhanced beta cell mass was due to a dramatic reduction of beta cell apoptosis without changes in proliferation. Whole genome gene profiling analysis of islets isolated from treated Irs2 -/- mice confirmed a broad impact of tungstate on cell death pathways. Mechanistically, tungstate induced Erk1/2 phosphorylation in islets in vitro and, in agreement, treated Irs2 -/- islets exhibited increased basal Erk1/2 phosphorylation. Tungstate also downregulated expression of apoptosis-related genes in Irs2-/- islets in vitro, uncovering a direct effect of this compound in islets. All together, our data demonstrate that tungstate can restore beta cell mass and glucose homeostasis in a context of deficient Insulin/Igf signaling. This study underscores the importance of developing strategies specifically designed to arrest beta cell apoptosis as a means to prevent progressive beta cell failure in diabetes. 10-week old WT and Irs2 -/- mice were randomly divided into two treatment group, in a total of 4 experimental groups. For 21 days one group received distilled water as drinking water (untreated group) whilst the other received ad libitum a solution of 2mg/ml of sodium tungstate in distilled water (treated group). For each experimental group 2 independent samples were analysed, in a total of 8 samples.
Project description:Relative beta cell deficit and increased beta cell apoptosis are hallmarks of type 2 diabetes (T2D). The Insulin/Insulin Growth Factor (Igf) signaling pathway is an established regulator of beta cell survival and is found downregulated in human T2D islets. The Insulin Receptor Substrate 2 (Irs2) plays a central role in the coordination of this pathway in beta cells. Thus, Irs2 knockout mice (Irs2 -/-) exhibit increased beta cell apoptosis that leads to a progressive decline of beta cell mass and hyperglycaemia. In this study, we sought to determine whether the anti-diabetic compound sodium tungstate could prevent the onset of diabetes in Irs2 -/- mice. Oral administration of tungstate resulted in an overall improvement in whole-body glucose tolerance in Irs2 -/- mice which correlated with increased beta cell mass. Enhanced beta cell mass was due to a dramatic reduction of beta cell apoptosis without changes in proliferation. Whole genome gene profiling analysis of islets isolated from treated Irs2 -/- mice confirmed a broad impact of tungstate on cell death pathways. Mechanistically, tungstate induced Erk1/2 phosphorylation in islets in vitro and, in agreement, treated Irs2 -/- islets exhibited increased basal Erk1/2 phosphorylation. Tungstate also downregulated expression of apoptosis-related genes in Irs2-/- islets in vitro, uncovering a direct effect of this compound in islets. All together, our data demonstrate that tungstate can restore beta cell mass and glucose homeostasis in a context of deficient Insulin/Igf signaling. This study underscores the importance of developing strategies specifically designed to arrest beta cell apoptosis as a means to prevent progressive beta cell failure in diabetes.
Project description:Glioblastoma cells are characterized by a highly invasive behavior whose mechanisms are not yet understood. Using the wound healing and Boyden chamber assays we compared in the present study the migration and invasion abilities of 5 glioblastoma cell lines (DK-MG, GaMG, U87-MG, U373-MG, SNB19) differing in p53 and PTEN status. We also analyzed by Western blotting the expression of PTEN, p53, mTOR and several other marker proteins involved in cell adhesion, migration and invasion. Among 5 cell lines, GaMG cells exhibited the fastest rate of wound closure, whereas U87-MG cells showed the most rapid chemotactic migration in the Boyden chamber assay. In DK-MG and GaMG cells, F-actin mainly occurred in the numerous stress fibers spanning the cytoplasm, whereas U87-MG, U373-MG and SNB19 cells preferentially expressed F-actin in filopodia and lamellipodia. Moreover, the two glioblastoma lines mutated in both p53 and PTEN genes (U373-MG and SNB19) were found to exhibit the fastest invasion rates through the Matrigel matrix.
Project description:Placentation requires the proper regulation of extravillous trophoblast (EVT) migration and invasion into the decidua and maternal vasculature, processes which are initiated in physiologic hypoxic conditions. Abnormal EVT migration and/or invasion have been suggested to lead to pregnancy complications, such as preeclampsia. The objectives of this study are to determine how exposure to hypoxia impacts gene expression and cellular motility of first trimester trophoblasts, and to assess if expression of migration-associated genes is dysregulated in 2nd trimester chorionic villous samples (CVS) from preeclampsia pregnancies relative to CVS from healthy pregnancies. The 1st trimester trophoblast cell line, HTR8/SVneo, was used to investigate the relationship between hypoxia and Notch signaling in trophoblast migration and invasion. RNA sequencing and quantitative RT-PCR analyses show that exposure to hypoxia (2.5% O2) activates Notch signaling in HTR-8/SVneo. We demonstrate that exposure of HTR-8/SVneo to hypoxia induces expression of genes associated with cellular migration and invasion and increases HTR-8/SVneo cellular migration and invasion, whereas inhibition of gamma-secretase decreases Notch signaling and decreases HTR-8/SVneo migration and invasion. Analysis of RNA sequencing data from CVS of preeclampsia and uncomplicated pregnancies identified significant differentially expressed genes that are involved in cellular migration and invasion. Decreased expression of migration and invasion genes in CVS from preeclampsia pregnancies, may impair trophoblast migration and invasion in the 2nd trimester of pregnancy, resulting in the development of preeclampsia.
Project description:We identified distinct sets of genes under the control of PRMT5 and E2F1. Some of the most highly regulated genes, such as cortactin/CTTN, influenced cell migration, invasion and adherence. We characterised the functional role of the cortactin/CTTN gene, which enabled PRMT5 through E2F1 to promote cellular migration and invasion, whilst decreasing cellular adherence. Most significantly, there was a striking coincidence between the expression of PRMT5 and E2F1 in certain human tumours, and elevated levels of PRMT5, E2F1 and cortactin/CTTN correlated with poor prognosis disease. Our results suggest a causal relationship between PRMT5, E2F1 and the migration and invasion of cancer cells, thereby highlighting an important pathway that contributes to the cancer biology of tumour cells.
Project description:Metastasis accounts for almost 90% of breast cancer-related fatalities, making it frequent malignancy and the main reason of tumor mortality globally among women. A key player in breast cancer is the histone demethylase lysine-specific demethylase 1 (LSD1). We used LSD1 knockdown MCF7 and T47D cell exosomes to treat breast cancer cells for greatly increasing the invasion and migration of breast cancer cells for evaluating the impact of LSD1 on breast cancer invasion and migration. miR-1290 expression was downregulated in LSD1 knockdown MCF7 exosomes. Furthermore, miR-1290 could control NAT1 expression by looking through the database of miR-1290 target genes. These data provide fresh insights into the biology of breast cancer therapy by demonstrating how the epigenetic factor LSD1 stimulates the breast cancer cells’ invasion and migration via controlling exosomal miRNA.
Project description:Colorectal cancer (CRC) is currently the fourth leading etiology of brain metastasis (BM). Yet, mechanisms supporting the formation of CRC BM are mostly unknown. In order to identify drivers that lead to tropism and adaptation of CRC cells to the brain environment, we analyzed an extensive genomic database, consisting of over 36,000 human CRC primary and metastasis samples. Several genomic alterations specific for BM were noted, among them increased prevalence of insulin receptor substrate 2 (IRS2) amplification, observed in 7.6% of BM, compared to only 2.9% of primary tumors or other metastatic sites (p<7E-05). This observation was validated by Immunohistochemistry studies of human clinical samples, showing increased expression of IRS2 protein in BM. IRS2 is a cytoplasmic adaptor mediating effects of insulin and IGF-1 receptors and is involved in more aggressive behavior of different cancer types. In order to study the ability of IRS2 to promote growth of CRC cells under brain microenvironment conditions, we employed an in vitro system consisting of cultured human astrocytes or their conditioned media. Indeed, IRS2-overexpressed CRC cells survived better and formed larger 3D spheres when grown in brain-mimicking conditions, while IRS2-silenced CRC cells showed a mirror image. Similarly, In vivo studies, using intracranial CRC BM mouse model, demonstrated that IRS2-overexpressed cells generated larger brain lesions, while silencing IRS2 dramatically decreased tumor outgrowth and extended survival. Transcriptomic analysis revealed enrichment of oxidative phosphorylation (OXPHOS) and Wnt/β-catenin pathways by IRS2. Indeed, IRS2-expressing cells showed increased mitochondrial activity and glycolysis-independent viability. Furthermore, IRS2-expressing cells had increased β-catenin transcriptional activity, and either β-catenin inhibition or IRS2 inhibition in IRS2-expressing cells decreased their viability, β-catenin transcriptional activity, and mitochondrial activity. These data suggest involvement of IRS2 in modulating OXPHOS through β-catenin. Exploiting this mechanism as a potential vulnerability allowed us to develop novel treatment strategies against CRC BM. NT219 is a novel IRS1/2 inhibitor already being tested in clinical trials. Treatment of mice harboring CRC BM with NT219 and 5-flourouracil reduced tumor growth and prolonged mice survival. These data reveal, for the first time, the unique genomic profile of CRC BM and imply the IRS2 role in promoting CRC BM. These effects may be mediated, at least in part, by modulation of the β-catenin and OXPHOS pathway. These findings may pave the way for clinical trials evaluation this novel IRS2-based strategy for the treatment of CRC BM.
Project description:Part I - SI-NET tumors High Resolution Isoelectric Focusing (HiRIEF) LC-MS and relative quantification by iTRAQ 8-plex was used to analyze 14 small intestinal neuroendocrine tumors (SI-NETs). The data was obtained from two separate TMT10plex sets and linked by a single internal pooled standard. The internal pooled standard was made by combining equal aliquots of the tryptic peptide mixtures from each of the 14 tissue samples. iTRAQ set1 was composed of 7 SI-NET samples, all from different individuals, and internal pooled standard labelled as follows: Channel 113 (sample Screen-1 with liver metastasis), Channel 114 (sample Screen-8 with liver metastasis), Channel 115 (sample Screen-3 with liver metastasis), Channel 116 (sample Screen-2 with liver metastasis), Channel 117 (sample Screen-5 no liver metastasis), Channel 118 (sample Screen-4 no liver metastasis), Channel 119 (sample Screen-10 no liver metastasis), Channel 121 (internal pooled standard). iTRAQ set2 was composed of 7 SI-NET samples, all from different individuals, and internal pooled standard labelled as follows: Channel 113 (sample Screen-7 with liver metastasis), Channel 114 (sample Screen-11 with liver metastasis), Channel 115 (sample Screen-13 with liver metastasis), Channel 116 (sample Screen-6 no liver metastasis), Channel 117 (sample Screen-12 no liver metastasis), Channel 118 (sample Screen-9 no liver metastasis), Channel 119 (sample Screen-14 no liver metastasis), Channel 121 (internal pooled standard). Part II - time course profiling in cell lines High Resolution Isoelectric Focusing (HiRIEF) LC-MS and relative quantification by TMT 10-plex was used to analyze cellular response to the neddylation inhibitor pevonedistat (MLN4924) at different timepoints in two SI-NET (small intestinal neuroendocrine tumors) cell lines. The data was obtained from two separate TMT 10-plex experiments. TMT set1 includes a time course experiment upon pevonedistat treatment of CNDT2 cells with harvests at 2h, 6h, 12h and 24h after treatment as well as of untreated control cells. Isobaric tag labelling of peptide samples with TMT10plex was used as follows. Biological duplicate controls (TMT channels 126, 127N), duplicate 2h (127C, 128N), duplicate 6h (128C, 129N), duplicate 12h (129C, 130N) and duplicate 24h (130C, 131) samples were employed. TMT set2 includes a time course experiment upon pevonedistat treatment of HC45 cells with harvests at 2h, 6h, 12h and 24h after treatment as well as of untreated control cells. Isobaric tag labelling of peptide samples with TMT10plex was used as follows. Biological duplicate controls (TMT channels 126, 127N), duplicate 2h (127C, 128N), duplicate 6h (128C, 129N), duplicate 12h (129C, 130N) and duplicate 24h (130C, 131) samples were employed.