Pituitary tumors contain a (CD31¯/CD45¯ purified) side population with 'tumor stem cell'-associated characteristics [set 2]
ABSTRACT: Pituitary adenomas cause significant endocrine and mass-related morbidity. Not much is known about mechanisms underlying pituitary tumor pathogenesis. We searched for a side population (SP) in pituitary tumor, representing cells with high efflux capacity and potentially enriching for cancer/tumor stem cells (CSC/TSC). Human pituitary adenomas contain a SP irrespective of hormonal phenotype. This adenoma SP, as well as the further purified SP (pSP) depleted from endothelial and immune cells, enriches for cells that express 'tumor stemness' markers and signaling pathways, including epithelial-mesenchymal transition (EMT)-linked factors. The adenomas were found to contain self-renewing sphere-forming cells, considered a property of TSC. The sphere-initiating cells were retrieved in the pSP. Because benign pituitary adenomas do not grow in vitro and failed to expand in immunodeficient mice, the pituitary tumor cell line AtT20 was further used. We identified a SP in this cell line and found it more tumorigenic than the main population (MP). Of the two EMT-regulatory pathways tested, inhibition of Cxcr4 signaling reduced EMT-linked cell motility in vitro as well as xenograft tumor growth, whereas activation of TGFβ had no effect. The tumor pSP showed upregulated expression of the pituitary stem cell marker SOX2. Pituitaries from dopamine receptor D2 knockout (Drd2-/-) mice bearing prolactinomas, contain more pSP, Sox2+ and colony-forming cells than wildtype glands. In conclusion, we detected a SP in pituitary tumors and identified TSC-associated characteristics. Our study may contribute to a better understanding of pituitary tumor pathogenesis and lead to new therapeutic targets. We determined gene expression profiles for 5 human pituitary adenoma samples (all NF-A type). The samples were obtained immediately after transsphenoidal resection (by the neurosurgeon Dr. van Loon, Division Neurosurgery, University Hospitals Leuven). Informed consent was received from the patients. Hormonal phenotype was determined by the Department of Imaging and Pathology (University Hospitals Leuven). For each sample, CD31¯/CD45¯ SP (purified SP or pSP) and pMP cells were sorted by FACS. Separate assays were run subsequently for the two fractions. As such we present data from 10 microarrays.
SUBMITTER: Heleen Roose Johannes van Loon Qiuli Fu Carolina Cristina Wouter Van Delm Olivier Govaere Lies Gremeaux Hugo Vankelecom Christophe Willems Marie Bex Damasia Becú-Villalobos Freya Mertens Jianghai Chen Tania Roskams
Pituitary tumors contain a side population with tumor stem cell-associated characteristics.
Mertens Freya F Gremeaux Lies L Chen Jianghai J Fu Qiuli Q Willems Christophe C Roose Heleen H Govaere Olivier O Roskams Tania T Cristina Carolina C Becú-Villalobos Damasia D Jorissen Mark M Poorten Vincent Vander VV Bex Marie M van Loon Johannes J Vankelecom Hugo H
Endocrine-related cancer 20150428 4
Pituitary adenomas cause significant endocrine and mass-related morbidity. Little is known about the mechanisms that underlie pituitary tumor pathogenesis. In the present study, we searched for a side population (SP) in pituitary tumors representing cells with high efflux capacity and potentially enriched for tumor stem cells (TSCs). Human pituitary adenomas contain a SP irrespective of hormonal phenotype. This adenoma SP, as well as the purified SP (pSP) that is depleted from endothelial and im ...[more]
Pituitary tumors contain a side population with 'tumor stem cell'-associated characteristics [set 1]
Project description:Pituitary adenomas cause significant endocrine and mass-related morbidity. Not much is known about mechanisms underlying pituitary tumor pathogenesis.We searched for a side population (SP) in pituitary tumor, representing cells with high efflux capacity and potentially enriching for cancer/tumor stem cells (CSC/TSC). Human pituitary adenomas contain a SP irrespective of hormonal phenotype. This adenoma SP, as well as the further purified SP (pSP) depleted from endothelial and immune cells, enriches for cells that express 'tumor stemness' markers and signaling pathways, including epithelial-mesenchymal transition (EMT)-linked factors. The adenomas were found to contain self-renewing sphere-forming cells, considered a property of TSC. The sphere-initiating cells were retrieved in the pSP.Because benign pituitary adenomas do not grow in vitro and failed to expand in immunodeficient mice, the pituitary tumor cell line AtT20 was further used. We identified a SP in this cell line and found it more tumorigenic than the main population (MP). Of the two EMT-regulatory pathways tested, inhibition of Cxcr4 signaling reduced EMT-linked cell motility in vitro as well as xenograft tumor growth, whereas activation of TGFβ had no effect.The tumor pSP showed upregulated expression of the pituitary stem cell marker SOX2. Pituitaries from dopamine receptor D2 knockout (Drd2-/-) mice bearing prolactinomas, contain more pSP, Sox2+ and colony-forming cells than wildtype glands.In conclusion, we detected a SP in pituitary tumors and identified TSC-associated characteristics. Our study may contribute to a better understanding of pituitary tumor pathogenesis and lead to new therapeutic targets. We determined gene expression profiles for 9 human pituitary adenoma samples (5 x NF-A; 4 x GH-A). The samples were obtained immediately after transsphenoidal resection (by the neurosurgeon Dr. van Loon, Division Neurosurgery, University Hospitals Leuven). Informed consent was received from the patients. Hormonal phenotype was determined by the Department of Imaging and Pathology (University Hospitals Leuven). For each sample, total SP and MP cells were sorted by FACS. Separate assays were run subsequently for the two fractions. As such we present data from 18 microarrays.
The side population of human pancreatic cancer expresses cancer stem cell-associated genes
Project description:Purpose: To explore the side population (SP) in pancreatic ductal adenocarcinoma (PDAC) for its gene expression profile and its association to cancer stem cells (CSC) and to evaluate the value of genes from its gene signature on patient survival. Experimental design: Side and main population (MP) cells were isolated from 11 human PDAC resection specimens using fluorescence-activated cell sorting (FACS) after Hoechst incubation. Total RNA was extracted for whole-genome analysis. A gene signature for the purified SP (pSP; depleted from immune/endothelial CD45+/CD31+ cells) was developed and validated with the nCounter system on expression data of 78 primary PDAC using Cox regression analyses for disease-free and overall survival. Results: An SP was identified in all PDAC samples. Whole-genome expression profiling of pSP revealed upregulation of genes related to therapy-resistance and of CSC-associated genes and pathways. A pSP signature of 32 up- or downregulated genes was capable of discriminating SP from MP in an independent set of 10 PDAC samples, and some contributing genes had a prognostic value in a separate series of 78 patients who underwent surgery for PDAC. Conclusion: Pancreatic cancer contains an SP with chemo-resistant and CSC-associated molecular characteristics. Genes from a newly defined pSP gene signature are related to survival of patients who undergo surgical resection for pancreatic cancer, and might therefore represent potential therapeutic targets. Microarray analysis was performed on SP and MP samples from 11 different human PDAC samples.
Transcription profiling of human pituitary non-invasive and invasive tumors
Project description:Pituitary adenomas are common benign neoplasms giving rise to disorders of growth, reproductive function and cortisol production. Although recently determined to be monoclonal, very little is known about the mechanisms regulating the development of pituitary hyperplasia and neoplasia in humans. Surgical resection is the treatment of choice for most symptomatic pituitary adenomas. The goal of surgery is the complete removal of the tumor and the success of surgery is strongly affected by the presence of local invasion. However, complete tumor removal is unlikely when there is extensive local invasion. Identifying genes that control the invasiveness and recurrence of this class of tumors will provide therapeutic targets for this class of tumors. We will determine the expression pattern of genes in recurrent and invasive and pituitary adenomas and compare those to non-invasive and non-recurrent tumors. We hypothesize that the differential expression and activation of a number of genes affect pituitary adenoma recurrence and invasiveness. Rationale: Preliminary result showed a differential expression of novel PKC isozymes in non-invasive and invasive pituitary adenomas. PMA, an activator of both novel and classical PKC isozymes increased the expression of gelatinase A (MMP-2) mRNA in human pituitary adenoma cell line. This result raises a fundamental question as to the functional role of novel PKC isozymes and proteases in the invasive phenotype of pituitary adenomas. The primary component of this Specific Aim is to determine whether specific genes are differentially expressed in recurrent or invasive adenomas when compared with control non-invasive tumors. Tissue specimens from non-invasive and invasive (dural invasion based microscopic examination) and recurrent vs non-recurrent tumors will be used for microarray analysis. Frozen pituitaryspecimens will be collected and total RNA extracted with TriZol reagent. We will provide total RNA (10 ug) from non-invasive, invasive, reoccurred and non-occurrent pituitary adenomas.
Hussaini-2R01NS035122-06A1
Project description:Pituitary adenomas are common benign neoplasms giving rise to disorders of growth, reproductive function and cortisol production. Although recently determined to be monoclonal, very little is known about the mechanisms regulating the development of pituitary hyperplasia and neoplasia in humans. Surgical resection is the treatment of choice for most symptomatic pituitary adenomas. The goal of surgery is the complete removal of the tumor and the success of surgery is strongly affected by the presence of local invasion. However, complete tumor removal is unlikely when there is extensive local invasion. Identifying genes that control the invasiveness and recurrence of this class of tumors will provide therapeutic targets for this class of tumors. We will determine the expression pattern of genes in recurrent and invasive and pituitary adenomas and compare those to non-invasive and non-recurrent tumors. We hypothesize that the differential expression and activation of a number of genes affect pituitary adenoma recurrence and invasiveness. Rationale: Preliminary result showed a differential expression of novel PKC isozymes in non-invasive and invasive pituitary adenomas. PMA, an activator of both novel and classical PKC isozymes increased the expression of gelatinase A (MMP-2) mRNA in human pituitary adenoma cell line. This result raises a fundamental question as to the functional role of novel PKC isozymes and proteases in the invasive phenotype of pituitary adenomas. The primary component of this Specific Aim is to determine whether specific genes are differentially expressed in recurrent or invasive adenomas when compared with control non-invasive tumors. Tissue specimens from non-invasive and invasive (dural invasion based microscopic examination) and recurrent vs non-recurrent tumors will be used for microarray analysis. Frozen pituitaryspecimens will be collected and total RNA extracted with TriZol reagent. We will provide total RNA (10 ug) from non-invasive, invasive, reoccurred and non-occurrent pituitary adenomas. Keywords: other
2006-02-14 | GSE4237 | GEO
Genome-wide evaluation of change in lncRNA expression in non-functioning pituitary adenoma using formalin-fixed and paraffin-embedded tissue specimens
Project description:Long noncoding RNAs (lncRNAs) have been implicated in the formation of many different types of tumors. However, expression profiles and potential functions of lncRNAs in non-functioning pituitary adenomas (NFPAs) have not been systematically evaluated. We evaluated the expression profiles and potential functions of lncRNAs in non-functioning pituitary adenomas (NFPAs). 10 formalin-fixed and paraffin-embedded (FFPE) tissue specimens (5 non-functioning pituitary adenomas (NFPAs) and 5 normal pituitaries(NPs)) were selected for RNA extraction and hybridization on Affymetrix microarrays. The NFPAs team was designed as the Tumor group (T), while the NPs team was designed as Normal group (N).
Gene expression analysis of growth hormone producing somatotroph pituitary adenomas
Project description:The epithelial marker E-cadherin plays a crucial role in epithelial mesenchymal transition (EMT). Decreased protein content in somatotroph adenomas has been associated with increased tumor size, invasion, and poor response to somatostatin analog (SA) treatment, but the potential mechanisms of EMT progression in these adenomas are lacking. Adenomas from sixteen acromegalic patients, eight with high (tertile 3)and eight with low (tertile 1) expression of E-cadherin where four adenomas treated with SA in each group, were screened for expressional candidate genes using Affymetrix human Gene Plus 2.0 Arrays. Analyses were performed to identify EMT-related transcripts. Expression levels were examined in adenomas from sixteen acromegalic patients, eight with high (tertile 3) and eight with low (tertile 1) expression of E-cadherin where four adenomas were treated with SA in each group.
Profiling Side Population Cells in Malignant Fibrous Histiocytoma
Project description:We are currently studying the mechanisms that confer tumour initiating potential upon SP, and as part of this work, we undertook gene profiling studies comparing expression between SP and non-SP cells, initially focusing on the most common soft tissue sarcoma, malignant fibrous histiocytoma (or MFH) Sarcomas contain a subpopulation of cells which exclude Hoechst dye (SP cells) and are enriched for tumor initiating potential. The persistence of SP cells could be responsible for relapse or a failed response to therapy. Expression profiles were compared between the SP and non-SP cells from malignant fibrous histiocytoma (MFH) tumors using microarray. The Hedgehog and Notch pathways were activated in SP cells. Blocking these pathways in MFH xenografts established in NOD-SCID mice depleted the abundance of SP cells and reduced tumor growth. Intriguingly, treatment also substantially inhibited the potential for successful secondary transplantation. The data provides support that SP cells act as tumor initiating cells in sarcomas and suggests targeting the SP as an enticing approach for sarcoma therapy. In this study, we studied six MFH tumours, and identified a number of signaling pathways that were consistently activated in the SP population compared to the non-SP population.
Gene expression profiling in human ACTH-secreting pituitary tumors
Project description:Corticotropin (ACTH)-secreting pituitary adenomas give rise to a severe endocrinological disorder, i.e., Cushing's disease, with multifaceted clinical presentation and treatment outcomes. Experimental studies suggested that disease variability is inherent to the pituitary tumor, thus pointing to the need for further studies into tumor biology. Aim of the present study was to evaluate transcriptome expression pattern in a large series of ACTH-secreting pituitary adenoma specimens, in order to identify molecular signatures of these tumors. Gene expression profiling of formalin-fixed paraffin-embedded specimens from 40 human ACTH-secreting pituitary adenomas revealed significant expression of genes involved in protein biosynthesis and ribosomal function, in keeping with neuroendocrine cell profile. Unsupervised cluster analysis identified three distinct gene profile clusters and several genes were uniquely overexpressed in a given cluster, accounting for different molecular signatures. Of note, gene expression profiles were associated with clinical features such as age and size of the tumor. Altogether, our studiy shows that corticotrope tumors are characterized by neuroendocrine gene expression profile and present subgroup-specific molecular features. Overall design: gene expression analysis of 40 RNA obtained from formalin-fixed paraffin-embedded pituitary human tissue
Development of diagnostic exosomal biomarkers for the detection of invasive non-functional pituitary adenomas (NFPAs)
Project description:The incomplete surgical resection of invasive non-functional pituitary adenomas (iNFPAs) carries the increased risk of complications and requires adjuvant radiotherapy and medications. Thus, the molecular mechanisms and markers of invasiveness must be identified to guide the management of NFPA patients. This study explores the proteomic and transcriptomic variations of invasive and non-invasive NFPAs and other types of pituitary adenomas and evaluates the genetic markers in the exosome related to iNFPAs. The exosome from invasive and non-invasive NFPAs, prolactinomas (PRLs), growth hormone–secreting adenomas (GHs), adrenocorticotropic hormone-secreting adenomas (ACTHs), and normal pituitary tissue were analyzed. We confirmed that elevated matrix metalloproteinase-1 (MMP1) expression and its production in the exosome (exo-MMP1) are correlated with the invasive characteristics of NFPA. To investigate the molecular mechanism underlying the role of exo-MMP1 in invasiveness, we analyzed the effects of MMP1 on cell migration, cell growth and tumor angiogenesis. After transfection of MMP1 or a shRNA expression vector into NFPA cells, we obtained the associated exosome and observed that the altered expression and production of MMP1 in the exosome was significantly synchronized with the transduction of NFPA cells. In addition, the enrichment of MMP1 in the exosome promoted cell migration, cell growth and tumor angiogenesis via protease-activated receptor-1 (PAR1) signaling in recipient cells. Thus, these data demonstrate that MMP1 plays an important role in tumor invasion and angiogenesis and show that an exosome-mediated regulatory pathway for MMP1 may represent a target for therapeutic treatment. Overall design: This study explores the transcriptomic variations of invasive (n=1) and non-invasive NFPAs (n=1) in the exosome.
Transcriptional analysis of apoptotic cerebellar granule neurons following rescue by Gip, Sp, Pacap and Igf1
Project description:Primary cultures of Cerebellar Granule Neurons (CGNs) have been extensively utilized to examine the signal transduction mechanisms underlying neuronal apoptosis. We conducted whole-genome expression profiling to decipher the transcriptional program controlling the apoptotic/survival switch in cerebellar granule neurons (CGNs) following the induction of apoptosis by serum and potassium deprivation and their rescue by gastric inhibitory polypeptide (Gip), substance p (Sp), insulin-like growth factor-1 (Igf1) or pituitary adenylyl cyclase-activating polypeptide (Pacap). Our results reveal the transcriptional changes intersecting neuronal apoptosis and survival and form the basis for further functional analyses and pharmacological exploitation to identify neuroprotective drugs. After six days "in vitro" (DIV), extracellular KCl of CGNs was shifted from 25 to 5 mM for neuronal apoptotic death induction. After two washes with serum-free BME containing 5 mM KCl, neurons were incubated with the same medium for 6 h (K5), while control neurons were incubated with serum free medium supplemented with 25 mM KCl (K25). K5 neurons were also treated with a maximal effective dose of Gip, Sp, Igf1 and Pacap. Four biological replicates (derived from the same litter) for each of the experimental conditions (K25, K5, K5 + Gip; K25, K5, K5 + Sp; K25, K5, K5 + Igf1; K25, K5, K5 + Pacap) were analyzed.