RESUMEN
With Alzheimer's disease (AD) exhibiting reduced ability of neural stem cell renewal, we hypothesized that de novo mutations controlling embryonic development, in the form of brain somatic mutations instigate the disease. A leading gene presenting heterozygous dominant de novo autism-intellectual disabilities (ID) causing mutations is activity-dependent neuroprotective protein (ADNP), with intact ADNP protecting against AD-tauopathy. We discovered a genomic autism ADNP mutation (c.2188C>T) in postmortem AD olfactory bulbs and hippocampi. RNA-Seq of olfactory bulbs also identified a novel ADNP hotspot mutation, c.2187_2188insA. Altogether, 665 mutations in 596 genes with 441 mutations in AD patients (389 genes, 38% AD-exclusive mutations) and 104 genes presenting disease-causing mutations (OMIM) were discovered. OMIM AD mutated genes converged on cytoskeletal mechanisms, autism and ID causing mutations (about 40% each). The number and average frequencies of AD-related mutations per subject were higher in AD subjects compared to controls. RNA-seq datamining (hippocampus, dorsolateral prefrontal cortex, fusiform gyrus and superior frontal gyrus-583 subjects) yielded similar results. Overlapping all tested brain areas identified unique and shared mutations, with ADNP singled out as a gene associated with autism/ID/AD and presenting several unique aging/AD mutations. The large fusiform gyrus library (117 subjects) with high sequencing coverage correlated the c.2187_2188insA ADNP mutation frequency to Braak stage (tauopathy) and showed more ADNP mutations in AD specimens. In cell cultures, the ADNP-derived snippet NAP inhibited mutated-ADNP-microtubule (MT) toxicity and enhanced Tau-MT association. We propose a paradigm-shifting concept in the perception of AD whereby accumulating mosaic somatic mutations promote brain pathology.
Asunto(s)
Enfermedad de Alzheimer , Trastorno Autístico , Proteínas de Homeodominio/genética , Discapacidad Intelectual , Proteínas del Tejido Nervioso/genética , Enfermedad de Alzheimer/genética , Trastorno Autístico/genética , Encéfalo/metabolismo , Humanos , MutaciónRESUMEN
MicroRNA (miRNA) profiling represents a promising source of cancer-related biomarkers. miRNA signatures are specific for each cancer type and subgroups of patients with diverse treatment sensitivity. Yet this miRNA potential has not been satisfactorily explored in rectal cancer (RC). The aim of the study was to identify the specific miRNA signature with clinical and therapeutic relevance for RC. Expressions of 2555 miRNA were examined in 20 pairs of rectal tumors and matched non-malignant tissues by 3D-Gene Toray microarray. Candidate miRNAs were validated in an independent cohort of 100 paired rectal tissues and in whole plasma and exosomes of 100 RC patients. To study the association of miRNA profile with therapeutic outcomes, plasma samples were taken repeatedly over a time period of 1 year reflecting thus patients' treatment responses. Finally, the most prominent miRNAs were investigated in vitro for their involvement in cell growth. We identified RC-specific miRNA signature that distinguishes responders from non-responders to adjuvant chemotherapy. A predominant part of identified miRNAs was represented by the members of miR-17/92 cluster. Upregulation of miRNA-17, -18a, -18b, -19a, -19b, -20a, -20b and -106a in tumor was associated with higher risk of tumor relapse and their overexpression in RC cell lines stimulated cellular proliferation. Examination of these miRNAs in plasma exosomes showed that their levels differed between RC patients and healthy controls and correlated with patient's treatment response. miRNAs from miR-17/92 cluster represent a non-invasive biomarker to predict posttreatment prognosis in RC patients.
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Antineoplásicos/uso terapéutico , MicroARNs/genética , Neoplasias del Recto/tratamiento farmacológico , Neoplasias del Recto/genética , Biomarcadores de Tumor/genética , Línea Celular Tumoral , Proliferación Celular/genética , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Neoplasias del Recto/mortalidad , Resultado del TratamientoRESUMEN
BACKGROUND: With the introduction of the first high-throughput qPCR instrument on the market it became possible to perform thousands of reactions in a single run compared to the previous hundreds. In the high-throughput reaction, only limited volumes of highly concentrated cDNA or DNA samples can be added. This necessity can be solved by pre-amplification, which became a part of the high-throughput experimental workflow. Here, we focused our attention on the limits of the specific target pre-amplification reaction and propose the optimal, general setup for gene expression experiment using BioMark instrument (Fluidigm). RESULTS: For evaluating different pre-amplification factors following conditions were combined: four human blood samples from healthy donors and five transcripts having high to low expression levels; each cDNA sample was pre-amplified at four cycles (15, 18, 21, and 24) and five concentrations (equivalent to 0.078 ng, 0.32 ng, 1.25 ng, 5 ng, and 20 ng of total RNA). Factors identified as critical for a success of cDNA pre-amplification were cycle of pre-amplification, total RNA concentration, and type of gene. The selected pre-amplification reactions were further tested for optimal Cq distribution in a BioMark Array. The following concentrations combined with pre-amplification cycles were optimal for good quality samples: 20 ng of total RNA with 15 cycles of pre-amplification, 20x and 40x diluted; and 5 ng and 20 ng of total RNA with 18 cycles of pre-amplification, both 20x and 40x diluted. CONCLUSIONS: We set up upper limits for the bulk gene expression experiment using gene expression Dynamic Array and provided an easy-to-obtain tool for measuring of pre-amplification success. We also showed that variability of the pre-amplification, introduced into the experimental workflow of reverse transcription-qPCR, is lower than variability caused by the reverse transcription step.
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Perfilación de la Expresión Génica/instrumentación , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Perfilación de la Expresión Génica/métodos , Voluntarios Sanos , Humanos , ARN Mensajero/análisis , ARN Mensajero/sangre , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/instrumentación , Sensibilidad y EspecificidadRESUMEN
DNA repair in blood cells was observed to be suboptimal in cancer patients at diagnosis, including colorectal cancer (CRC). To explore the causality of this phenomenon, we studied the dynamics of DNA repair from diagnosis to 1 yr follow-up, and with respect to CRC treatment. Systemic CRC therapy is targeted to DNA damage induction and DNA repair is thus of interest. CRC patients were blood-sampled three times in 6-mo intervals, starting at the diagnosis, and compared to healthy controls. DNA repair was characterized by mRNA levels of 40 repair genes, by capacity of nucleotide excision repair (NER), and by levels of DNA strand breaks (SBs). NER and base excision repair genes were significantly under-expressed (P < 0.016) in patients at diagnosis compared to controls, in accordance with reduced NER function (P = 0.008) and increased SBs (P = 0.015). Six months later, there was an increase of NER capacity, but not of gene expression levels, in treated patients only. A year from diagnosis, gene expression profiles and NER capacity were significantly modified in all patients and were no longer different from those measured in controls. All patients were free of relapse at the last sampling, so we were unable to clarify the impact of DNA repair parameters on treatment response. However, we identified a panel of blood DNA repair-related markers discerning acute stage of the disease from the remission period. In conclusion, our results support a model in which DNA repair is altered as a result of cancer.
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Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Reparación del ADN , Anciano , Estudios de Casos y Controles , Colon/efectos de los fármacos , Colon/metabolismo , Neoplasias Colorrectales/sangre , Roturas del ADN/efectos de los fármacos , Reparación del ADN/efectos de los fármacos , Femenino , Estudios de Seguimiento , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Recto/efectos de los fármacos , Recto/metabolismoRESUMEN
BACKGROUND: Mismatch repair (MMR) genes are known to be frequently altered in colorectal cancer (CRC). Both genetics and epigenetics modifications seems to be relevant in this phenomenon, however it is still not clear how these two aspects are interconnected. The present study aimed at characterizing of epigenetic and gene expression profiles of MMR genes in sporadic CRC patients from the Czech Republic, a country with one of the highest incidences of this cancer all over Europe. METHODS: Expression levels and CpG promoter methylation status of all MMR genes were evaluated in DNA from tumor and adjacent mucosal samples of 53 incident CRC patients. RESULTS: We have found significantly increased transcription levels in EXO1 gene in tumor tissues (P = 0.05) and significant over-expression of MSH3 gene in colon tumors when compared to adjacent mucosal tissues (P = 0.02). Interestingly, almost all MMR genes were differently expressed when localization of tumors was compared. In particular, colon tumors showed an up-regulation of EXO1, MSH2, MSH3, MSH6, and PMS2 genes in comparison to rectal tumors (P = 0.02). Expression levels of all MMR genes positively correlated between each other. The promoter methylation of MLH1 gene was observed in 9% of CRC tissues only. CONCLUSIONS: In our study, we have observed different pattern of MMR genes expression according to tumor localization. However, a lack of association between methylation in MMR genes and their corresponding expressions was noticed in this study, the relationship between these two aspects is worthy to be analyzed in larger population studies and in pre-malignant stages.
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Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN/genética , Anciano , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/patología , República Checa/epidemiología , Metilación de ADN , Epigénesis Genética , Femenino , Perfilación de la Expresión Génica , Humanos , Incidencia , Masculino , Inestabilidad de Microsatélites , Regiones Promotoras Genéticas/genéticaRESUMEN
BACKGROUND: Giardiasis, caused by the protozoan parasite Giardia intestinalis, often presents a treatment challenge, particularly in terms of resistance to metronidazole. Despite extensive research, markers for metronidazole resistance have not yet been identified. METHODS: This study analysed 28 clinical samples of G. intestinalis from sub-assemblage AII, characterised by varying responses to metronidazole treatment. We focussed on copy number variation (CNV) of the multi-copy flavohemoprotein gene, analysed using digital polymerase chain reaction (dPCR) and next generation sequencing (NGS). Additionally, chromosomal ploidy was tested in 18 of these samples. Flavohemoprotein CNV was also assessed in 17 samples from other sub-assemblages. RESULTS: Analyses revealed variable CNVs of the flavohemoprotein gene among the isolates, with no correlation to clinical metronidazole resistance. Discrepancies in CNVs detected from NGS data were attributed to biases linked to the whole genome amplification. However, dPCR helped to clarify these discrepancies by providing more consistent CNV data. Significant differences in flavohemoprotein CNVs were observed across different G. intestinalis sub-assemblages. Notably, Giardia exhibits a propensity for aneuploidy, contributing to genomic variability within and between sub-assemblages. CONCLUSIONS: The complexity of the clinical metronidazole resistance in Giardia is influenced by multiple genetic factors, including CNVs and aneuploidy. No significant differences in the CNV of the flavohemoprotein gene between isolates from metronidazole-resistant and metronidazole-sensitive cases of giardiasis were found, underscoring the need for further research to identify reliable genetic markers for resistance. We demonstrate that dPCR and NGS are robust methods for analysing CNVs and provide cross-validating results, highlighting their utility in the genetic analyses of this parasite.
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Antiprotozoarios , Variaciones en el Número de Copia de ADN , Resistencia a Medicamentos , Giardia lamblia , Giardiasis , Metronidazol , Giardia lamblia/genética , Giardia lamblia/efectos de los fármacos , Metronidazol/farmacología , Resistencia a Medicamentos/genética , Humanos , Giardiasis/parasitología , Giardiasis/tratamiento farmacológico , Antiprotozoarios/farmacología , Secuenciación de Nucleótidos de Alto Rendimiento , Proteínas Protozoarias/genéticaRESUMEN
Altered expression and methylation pattern of tumor suppressor and DNA repair genes, in particular involved in mismatch repair (MMR) pathway, frequently occur in primary colorectal (CRC) tumors. However, little is known about (epi)genetic changes of these genes in precancerous and early stages of CRC. The aim of this pilot study was to analyze expression profile and promoter methylation status of important tumor suppressor and DNA repair genes in the early stages of experimentally induced colorectal carcinogenesis. Rats were treated with azoxymethane (AOM), dextran sodium sulphate (DSS) or with their combination, and sacrificed 1 or 4 months post-treatment period. The down-regulation of Apc expression in left colon, detectable in animals treated with DSS-AOM and sacrificed 1 month after the end of treatment, represents most early marker of the experimental colorectal carcinogenesis. Significantly reduced gene expressions were also found in 5 out of 7 studied MMR genes (Mlh1, Mlh3, Msh3 Pms1, Pms2), regarding the sequential administration of DSS-AOM at 4 months since the treatment. Strong down-regulation was also discovered for Apc, Apex1, Mgmt and TP53. Tumors developed in rectum-sigmoid region displayed significantly lower Apc and Pms2 expressions. The decreased expression of studied genes was not in any case associated with aberrant methylation of promoter region. Present data suggest that down-regulation of Apc and MMR genes are prerequisite for the development of CRC. In this study we addressed for the first time early functional alterations of tumor suppressor genes with underlying epigenetic mechanisms in experimentally induced CRC in rats.
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Neoplasias del Colon/genética , Metilación de ADN/genética , Regulación Neoplásica de la Expresión Génica , Proteínas Supresoras de Tumor/genética , Animales , Colon/metabolismo , Colon/patología , Masculino , Proyectos Piloto , Reacción en Cadena de la Polimerasa , Ratas , Ratas Wistar , Proteínas Supresoras de Tumor/metabolismoRESUMEN
MUC13, a transmembrane mucin glycoprotein, is overexpressed in colorectal cancer (CRC), however, its regulation and functions are not fully understood. It has been shown that MUC13 protects colonic epithelial cells from apoptosis. Therefore, studying MUC13 and MUC13-regulated pathways may reveal promising therapeutic approaches for CRC treatment. Growing evidence suggests that microRNAs (miRs) are involved in the development and progression of CRC. In the present study, the MUC13-miR-4647 axis was addressed in association with survival of patients. miR-4647 is predicted in silico to bind to the MUC13 gene and was analyzed by RT-qPCR in 187 tumors and their adjacent non-malignant mucosa of patients with CRC. The impact of previously mentioned genes on survival and migration abilities of cancer cells was validated in vitro. Significantly upregulated MUC13 (P=0.02) in was observed tumor tissues compared with non-malignant adjacent mucosa, while miR-4647 (P=0.05) showed an opposite trend. Higher expression levels of MUC13 (log-rank P=0.05) were associated with worse patient's survival. The ectopic overexpression of studied miR resulted in decreased migratory abilities and worse survival of cells. Attenuated MUC13 expression levels confirmed the suppression of colony forming of CRC cells. In summary, the present data suggested the essential role of MUC13-miR-4647 in patients' survival, and this axis may serve as a novel therapeutic target. It is anticipated MUC13 may hold significant potential in the screening, diagnosis and treatment of CRC.
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Di-(2-ethylhexyl)-phthalate (DEHP) is a compound widely used as a plasticizer, which can leach from plastics into the environment and thus influence human health. The aim of this study was to analyze whether exposure to an environmentally relevant dose of DEHP during mice fetal development or puberty can cause long-lasting changes detectable month/s after the last exposure. We used a DEHP concentration relevant to a daily human intake of 2.4-3⯵g/kg of body weight/day. CD1 outbred mice were treated either in utero or postnatally during puberty and analyzed in adulthood. Analyzing fertility parameters using morphometric, histologic, genomic and proteomic methods we showed that DEHP exposure leads to decreased sperm concentration and quality, in both experimental groups. Moreover, the changes in anogenital distance, seminal vesicle weight, and testicular gene expression suggest a disturbance of androgen signaling in exposed animals. In conclusion, we hereby present, that the prenatal and pubertal exposure to a low dose of DEHP negatively influenced reproductive endpoints in male mice, and some of the effects were persistent until adulthood.
Asunto(s)
Dietilhexil Ftalato/toxicidad , Disruptores Endocrinos/toxicidad , Plastificantes/toxicidad , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Maduración Sexual/efectos de los fármacos , Canal Anal/anatomía & histología , Canal Anal/efectos de los fármacos , Animales , Femenino , Regulación del Desarrollo de la Expresión Génica/efectos de los fármacos , Genitales Masculinos/anatomía & histología , Genitales Masculinos/efectos de los fármacos , Masculino , Intercambio Materno-Fetal , Ratones Endogámicos ICR , Embarazo , Efectos Tardíos de la Exposición Prenatal/genética , Espermatozoides/efectos de los fármacos , Testículo/anatomía & histología , Testículo/efectos de los fármacosRESUMEN
Given our recent discovery of somatic mutations in autism spectrum disorder (ASD)/intellectual disability (ID) genes in postmortem aged Alzheimer's disease brains correlating with increasing tauopathy, it is important to decipher if tauopathy is underlying brain imaging results of atrophy in ASD/ID children. We concentrated on activity-dependent neuroprotective protein (ADNP), a prevalent autism gene. The unique availability of multiple postmortem brain sections of a 7-year-old male, heterozygous for ADNP de novo mutation c.2244Adup/p.His559Glnfs*3 allowed exploration of tauopathy, reflecting on a general unexplored mechanism. The tested subject exhibited autism, fine motor delays, severe intellectual disability and seizures. The patient died after multiple organ failure following liver transplantation. To compare to other ADNP syndrome mutations, immortalized lymphoblastoid cell lines from three different patients (including ADNP p.Arg216*, p.Lys408Valfs*31, and p.Tyr719* heterozygous dominant mutations) and a control were subjected to RNA-seq. Immunohistochemistry, high-throughput gene expression profiles in numerous postmortem tissues followed. Comparisons to a control brain and to extensive datasets were used. Live cell imaging investigated Tau-microtubule interaction, protecting against tauopathy. Extensive child brain tauopathy paralleled by multiple gene expression changes was discovered. Tauopathy was explained by direct mutation effects on Tau-microtubule interaction and correction by the ADNP active snippet NAP. Significant pathway changes (empirical P value < 0.05) included over 100 genes encompassing neuroactive ligand-receptor and cytokine-cytokine receptor interaction, MAPK and calcium signaling, axon guidance and Wnt signaling pathways. Changes were also seen in steroid biosynthesis genes, suggesting sex differences. Selecting the most affected genes by the ADNP mutations for gene expression analysis, in multiple postmortem tissues, identified Tau (MAPT)-gene-related expression changes compared with extensive normal gene expression (RNA-seq) databases. ADNP showed relatively reduced expression in the ADNP syndrome cerebellum, which was also observed for 25 additional genes (representing >50% of the tested genes), including NLGN1, NLGN2, PAX6, SMARCA4, and SNAP25, converging on nervous system development and tauopathy. NAP provided protection against mutated ADNP disrupted Tau-microtubule association. In conclusion, tauopathy may explain brain-imaging findings in ADNP syndrome children and may provide a new direction for the development of tauopathy protecting drug candidates like NAP in ASD/ID.
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Trastorno del Espectro Autista , Trastorno Autístico , Tauopatías , Anciano , Trastorno del Espectro Autista/genética , Biomarcadores , Encéfalo/diagnóstico por imagen , Encéfalo/metabolismo , Niño , ADN Helicasas , Femenino , Proteínas de Homeodominio/metabolismo , Humanos , Masculino , Proteínas del Tejido Nervioso , Proteínas Nucleares , Tauopatías/genética , Factores de TranscripciónRESUMEN
Adaptation to continuous normobaric hypoxia (CNH) protects the heart against acute ischemia/reperfusion injury. Recently, we have demonstrated the infarct size-limiting effect of CNH also in hearts of spontaneously hypertensive rats (SHR) and in conplastic SHR-mtBN strain characterized by the selective replacement of the mitochondrial genome of SHR with that of more ischemia-resistant Brown Norway rats. Importantly, cardioprotective effect of CNH was more pronounced in SHR-mtBN than in SHR. Thus, here we aimed to identify candidate genes which may contribute to this difference between the strains. Rats were adapted to CNH (FiO2 0.1) for 3 weeks or kept at room air as normoxic controls. Screening of 45 transcripts was performed in left ventricles using Biomark Chip. Significant differences between the groups were analyzed by univariate analysis (ANOVA) and the genes contributing to the differences between the strains unmasked by CNH were identified by multivariate analyses (PCA, SOM). ANOVA with Bonferroni correction revealed that transcripts differently affected by CNH in SHR and SHR-mtBN belong predominantly to lipid metabolism and antioxidant defense. PCA divided four experimental groups into two main clusters corresponding to chronically hypoxic and normoxic groups, and differences between the strains were more pronounced after CNH. Subsequently, the following 14 candidate transcripts were selected by PCA, and confirmed by SOM analyses, that can contribute to the strain differences in cardioprotective phenotype afforded by CNH: Alkaline ceramidase 2 (Acer2), Fatty acid translocase (Cd36), Aconitase 1 (Aco1), Peroxisome proliferator activated receptor gamma (Pparg), Hemoxygenase 2 (Hmox2), Phospholipase A2 group IIA (Ppla2g2a), Dynamin-related protein (Drp), Protein kinase C epsilon (Pkce), Hexokinase 2 (Hk2), Sphingomyelin synthase 2 (Sgms2), Caspase 3 (Casp3), Mitofussin 1 (Mfn1), Phospholipase A2 group V (Pla2g5), and Catalase (Cat). Our data suggest that the stronger cardioprotective phenotype of conplastic SHR-mtBN strain afforded by CNH is associated with either preventing the drop or increasing the expression of transcripts related to energy metabolism, antioxidant response and mitochondrial dynamics.
RESUMEN
Previous findings showed that in mice, complete knockout of activity-dependent neuroprotective protein (ADNP) abolishes brain formation, while haploinsufficiency (Adnp+/-) causes cognitive impairments. We hypothesized that mutations in ADNP lead to a developmental/autistic syndrome in children. Indeed, recent phenotypic characterization of children harboring ADNP mutations (ADNP syndrome children) revealed global developmental delays and intellectual disabilities, including speech and motor dysfunctions. Mechanistically, ADNP includes a SIP motif embedded in the ADNP-derived snippet drug candidate NAP (NAPVSIPQ, also known as CP201), which binds to microtubule end-binding protein 3, essential for dendritic spine formation. Here, we established a unique neuronal membrane-tagged, GFP-expressing Adnp+/- mouse line allowing in vivo synaptic pathology quantification. We discovered that Adnp deficiency reduced dendritic spine density and altered synaptic gene expression, both of which were partly ameliorated by NAP treatment. Adnp+/-mice further exhibited global developmental delays, vocalization impediments, gait and motor dysfunctions, and social and object memory impairments, all of which were partially reversed by daily NAP administration (systemic/nasal). In conclusion, we have connected ADNP-related synaptic pathology to developmental and behavioral outcomes, establishing NAP in vivo target engagement and identifying potential biomarkers. Together, these studies pave a path toward the clinical development of NAP (CP201) for the treatment of ADNP syndrome.
Asunto(s)
Trastorno Autístico/metabolismo , Espinas Dendríticas/metabolismo , Modelos Neurológicos , Proteínas del Tejido Nervioso/deficiencia , Sinapsis/metabolismo , Secuencias de Aminoácidos , Animales , Trastorno Autístico/genética , Trastorno Autístico/patología , Trastorno Autístico/fisiopatología , Conducta Animal , Biomarcadores/metabolismo , Membrana Celular/genética , Membrana Celular/metabolismo , Membrana Celular/patología , Espinas Dendríticas/patología , Regulación de la Expresión Génica , Proteínas de Homeodominio , Humanos , Ratones , Ratones Noqueados , Microtúbulos/genética , Microtúbulos/metabolismo , Microtúbulos/patología , Mutación , Naftoquinonas/farmacología , Sinapsis/patología , SíndromeRESUMEN
The importance of iron in the growth and progression of tumors has been widely documented. In this report, we show that tumor-initiating cells (TICs), represented by spheres derived from the MCF7 cell line, exhibit higher intracellular labile iron pool, mitochondrial iron accumulation and are more susceptible to iron chelation. TICs also show activation of the IRP/IRE system, leading to higher iron uptake and decrease in iron storage, suggesting that level of properly assembled cytosolic iron-sulfur clusters (FeS) is reduced. This finding is confirmed by lower enzymatic activity of aconitase and FeS cluster biogenesis enzymes, as well as lower levels of reduced glutathione, implying reduced FeS clusters synthesis/utilization in TICs. Importantly, we have identified specific gene signature related to iron metabolism consisting of genes regulating iron uptake, mitochondrial FeS cluster biogenesis and hypoxic response (ABCB10, ACO1, CYBRD1, EPAS1, GLRX5, HEPH, HFE, IREB2, QSOX1 and TFRC). Principal component analysis based on this signature is able to distinguish TICs from cancer cells in vitro and also Leukemia-initiating cells (LICs) from non-LICs in the mouse model of acute promyelocytic leukemia (APL). Majority of the described changes were also recapitulated in an alternative model represented by MCF7 cells resistant to tamoxifen (TAMR) that exhibit features of TICs. Our findings point to the critical importance of redox balance and iron metabolism-related genes and proteins in the context of cancer and TICs that could be potentially used for cancer diagnostics or therapy.
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Neoplasias de la Mama/genética , Hierro/metabolismo , Células Madre Neoplásicas/enzimología , Neoplasias de la Próstata/genética , Transcriptoma , Animales , Antineoplásicos/farmacología , Transporte Biológico , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/enzimología , Neoplasias de la Mama/patología , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos , Femenino , Perfilación de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Quelantes del Hierro/farmacología , Leucemia Promielocítica Aguda/enzimología , Leucemia Promielocítica Aguda/genética , Células MCF-7 , Masculino , Ratones Transgénicos , Mitocondrias/enzimología , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Fenotipo , Análisis de Componente Principal , Neoplasias de la Próstata/tratamiento farmacológico , Neoplasias de la Próstata/enzimología , Neoplasias de la Próstata/patología , Esferoides Celulares , Tamoxifeno/farmacologíaRESUMEN
Successful molecular analyses of human solid tissues require intact biological material with well-preserved nucleic acids, proteins, and other cell structures. Pre-analytical handling, comprising of the collection of material at the operating theatre, is among the first critical steps that influence sample quality. The aim of this study was to compare the experimental outcomes obtained from samples collected and stored by the conventional means of snap freezing and by PAXgene Tissue System (Qiagen). These approaches were evaluated by measuring rRNA and mRNA integrity of the samples (RNA Quality Indicator and Differential Amplification Method) and by gene expression profiling. The collection procedures of the biological material were implemented in two hospitals during colon cancer surgery in order to identify the impact of the collection method on the experimental outcome. Our study shows that the pre-analytical sample handling has a significant effect on the quality of RNA and on the variability of qPCR data. PAXgene collection mode proved to be more easily implemented in the operating room and moreover the quality of RNA obtained from human colon tissues by this method is superior to the one obtained by snap freezing.
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Carcinoma/química , Colon/química , Neoplasias del Colon/química , Criopreservación/métodos , Proteínas de Neoplasias/genética , Preservación Biológica/métodos , ARN Neoplásico/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Manejo de Especímenes/métodos , Carcinoma/cirugía , Neoplasias del Colon/cirugía , Criopreservación/instrumentación , ADN-Topoisomerasas de Tipo I/genética , ADN de Neoplasias/genética , ADN Ribosómico/genética , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica , Ensayos Analíticos de Alto Rendimiento/instrumentación , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Proteínas de Neoplasias/biosíntesis , Nitrógeno , Soluciones Preservantes de Órganos , Preservación Biológica/instrumentación , Control de Calidad , ARN Neoplásico/análisis , ARN Neoplásico/genética , ARN Ribosómico 18S/genética , Reacción en Cadena en Tiempo Real de la Polimerasa/instrumentación , Reproducibilidad de los Resultados , Manejo de Especímenes/instrumentación , Fijación del Tejido/métodosRESUMEN
One purpose of the EC funded project, SPIDIA, is to develop evidence-based quality guidelines for the pre-analytical handling of blood samples for RNA molecular testing. To this end, two pan-European External Quality Assessments (EQAs) were implemented. Here we report the results of the second SPIDIA-RNA EQA. This second study included modifications in the protocol related to the blood collection process, the shipping conditions and pre-analytical specimen handling for participants. Participating laboratories received two identical proficiency blood specimens collected in tubes with or without an RNA stabilizer. For pre-defined specimen storage times and temperatures, laboratories were asked to perform RNA extraction from whole blood according to their usual procedure and to return extracted RNA to the SPIDIA facility for further analysis. These RNA samples were evaluated for purity, yield, integrity, stability, presence of interfering substances, and gene expression levels for the validated markers of RNA stability: FOS, IL1B, IL8, GAPDH, FOSB and TNFRSF10c. Analysis of the gene expression results of FOS, IL8, FOSB, and TNFRSF10c, however, indicated that the levels of these transcripts were significantly affected by blood collection tube type and storage temperature. These results demonstrated that only blood collection tubes containing a cellular RNA stabilizer allowed reliable gene expression analysis within 48 h from blood collection for all the genes investigated. The results of these two EQAs have been proposed for use in the development of a Technical Specification by the European Committee for Standardization.
Asunto(s)
Recolección de Muestras de Sangre/métodos , ARN/sangre , Proteínas Ligadas a GPI/genética , Perfilación de la Expresión Génica , Humanos , Interleucina-1beta/genética , Proteínas Proto-Oncogénicas c-fos/genética , Control de Calidad , ARN/genética , Miembro 10c de Receptores del Factor de Necrosis Tumoral , Receptores Señuelo del Factor de Necrosis Tumoral/genéticaRESUMEN
There is an increasing need for proper quality control tools in the pre-analytical phase of the molecular diagnostic workflow. The aim of the present study was to identify biomarkers for monitoring pre-analytical mRNA quality variations in two different types of blood collection tubes, K2EDTA (EDTA) tubes and PAXgene Blood RNA Tubes (PAXgene tubes). These tubes are extensively used both in the diagnostic setting as well as for research biobank samples. Blood specimens collected in the two different blood collection tubes were stored for varying times at different temperatures, and microarray analysis was performed on resultant extracted RNA. A large set of potential mRNA quality biomarkers for monitoring post-phlebotomy gene expression changes and mRNA degradation in blood was identified. qPCR assays for the potential biomarkers and a set of relevant reference genes were generated and used to pre-validate a sub-set of the selected biomarkers. The assay precision of the potential qPCR based biomarkers was determined, and a final validation of the selected quality biomarkers using the developed qPCR assays and blood samples from 60 healthy additional subjects was performed. In total, four mRNA quality biomarkers (USP32, LMNA, FOSB, TNRFSF10C) were successfully validated. We suggest here the use of these blood mRNA quality biomarkers for validating an experimental pre-analytical workflow. These biomarkers were further evaluated in the 2nd ring trial of the SPIDIA-RNA Program which demonstrated that these biomarkers can be used as quality control tools for mRNA analyses from blood samples.
Asunto(s)
ARN Mensajero/sangre , Recolección de Muestras de Sangre , Perfilación de la Expresión Génica , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa , Estabilidad del ARN , ARN Mensajero/química , ARN Mensajero/genética , ARN Mensajero/aislamiento & purificaciónRESUMEN
PURPOSE: DNA repair capacity (DRC) is a determinant not only of cancer development but also of individual response to therapy. Previously, altered base and nucleotide excision repair (BER and NER) have been described in lymphocytes of patients with sporadic colorectal cancer. We, for the first time, evaluate both excision repair capacities in human colon biopsies to study their participation in colorectal tumorigenesis. EXPERIMENTAL DESIGN: Seventy pairs of tumor and adjacent healthy tissues were analyzed for BER- and NER-specific DRC by a comet repair assay. Tissue pairs were further compared for expression levels of a panel of 25 BER and NER genes complemented by their promoter methylation status. RESULTS: We observed a moderate increase of NER-DRC (P = 0.019), but not of BER-DRC in tumors. There was a strong correlation between both tissues for all investigated parameters (P < 0.001). However, 4 NER (CSB, CCNH, XPA, XPD) and 4 BER (NEIL1, APEX1, OGG1, PARP1) genes showed a 1.08- to 1.28-fold change difference in expression in tumors (P < 0.05). Individual gene expression levels did not correlate with overall DRC, and we did not detect any aberrant methylation of the investigated genes. CONCLUSIONS: Our complex analysis showed that tumor cells are not deficient in BER and NER, but rather follow patterns characteristic for each individual and are comparable with adjacent tissue. Alteration of excision repair pathways is not a pronounced event in colorectal carcinogenesis. This study shows the feasibility of DRC evaluation in human solid tissues, representing a complex marker of multigene DNA repair processes.