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Accumulating data suggest that metastatic dissemination often occurs early during tumour formation, but the mechanisms of early metastatic spread have not yet been addressed. Here, by studying metastasis in a HER2-driven mouse breast cancer model, we show that progesterone-induced signalling triggers migration of cancer cells from early lesions shortly after HER2 activation, but promotes proliferation in advanced primary tumour cells. The switch from migration to proliferation was regulated by increased HER2 expression and tumour-cell density involving microRNA-mediated progesterone receptor downregulation, and was reversible. Cells from early, low-density lesions displayed more stemness features, migrated more and founded more metastases than cells from dense, advanced tumours. Notably, we found that at least 80% of metastases were derived from early disseminated cancer cells. Karyotypic and phenotypic analysis of human disseminated cancer cells and primary tumours corroborated the relevance of these findings for human metastatic dissemination.
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Many biological or pathological processes are driven by cells difficult to identify or isolate, i.e., rare cells. Very often, these cells have elusive biology. Therefore, their detailed characterization is of utmost importance. There are many approaches that allow analysis of few or even many targets within one class of biomacromolecules/analytes (e.g., DNA, RNA, proteins, etc.) in single cells. However, due to rarity of the cells of interest, there is a great need to comprehensively analyze multiple analytes within these cells, in other words to perform multi-omics analysis. In this chapter, I describe a method to isolate, separate, and amplify total mRNA and genomic DNA of a single cells, using whole transcriptome (WTA) and whole genome amplification (WGA). These WTA and WGA products enable simultaneous analysis of transcriptome and genome of a single cell using various downstream high-throughput approaches.
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DNA , RNA , RNA Mensageiro/genética , DNA/genética , Transcriptoma , GenômicaRESUMO
Dormant disseminated cancer cells, arrested and nonproliferating, are "good" cancer cells because there is no need to worry unless they resume growth. The mechanisms by which dormant disseminated cancer cells are put to sleep at distant sites and re-awakened are poorly understood. Moreover, it is not clear whether re-awakened cancer cells have a role in disease courses. Cyrus Ghajar and colleagues identified a mechanism of dormancy and growth resumption that might become important when more closely linked to clinical reality.
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Neoplasias da Medula Óssea/secundário , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Endotélio Vascular/patologia , Neoplasias Pulmonares/secundário , Neoplasia Residual/patologia , Neovascularização Patológica , Pericitos/patologia , Animais , Feminino , HumanosRESUMO
At the moment of union in fertilization, sperm and oocyte are transcriptionally silent. The ensuing onset of embryonic transcription (embryonic genome activation [EGA]) is critical for development, yet its timing and profile remain elusive in any vertebrate species. We here dissect transcription during EGA by high-resolution single-cell RNA sequencing of precisely synchronized mouse one-cell embryos. This reveals a program of embryonic gene expression (immediate EGA [iEGA]) initiating within 4 h of fertilization. Expression during iEGA produces canonically spliced transcripts, occurs substantially from the maternal genome, and is mostly downregulated at the two-cell stage. Transcribed genes predict regulation by transcription factors (TFs) associated with cancer, including c-Myc. Blocking c-Myc or other predicted regulatory TF activities disrupts iEGA and induces acute developmental arrest. These findings illuminate intracellular mechanisms that regulate the onset of mammalian development and hold promise for the study of cancer.
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Embrião de Mamíferos , Perfilação da Expressão Gênica , Masculino , Animais , Camundongos , Embrião de Mamíferos/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Sêmen , Expressão Gênica , Desenvolvimento Embrionário/genética , Mamíferos/genéticaRESUMO
BACKGROUND: We assessed a wide array of body composition parameters to identify those most relevant as prognostic tools for patients undergoing radical cystectomy (RC) due to bladder cancer (BC). METHODS: In this retrospective, single-center study, preoperative computed tomography (CT) scans of 657 patients were measured at the level of the 3rd lumbar vertebra (L3) to determine common body composition indices including sarcopenia, myosteatosis, psoas muscle index (PMI), subcutaneous and visceral fat index (SFI and VFI), visceral-to-subcutaneous fat ratio (VSR), and visceral obesity. Predictors of overall survival (OS) and cancer-specific survival (CSS) were identified in univariate and multivariate survival analysis. RESULTS: Sarcopenia and a low PMI were independently associated with shorter OS (Sarcopenia: HR 1.30; 95% CI 1.02-1.66; p = 0.04 and a low PMI: HR 1.32; 95% CI 1.02-1.70; p = 0.03) and CSS (Sarcopenia: HR 1.64; 95% CI 1.19-2.25; p < 0.01 and a low PMI: HR 1.41; 95% CI 1.02-1.96; p = 0.04). Myosteatosis, measured as decreasing average Hounsfield units of skeletal muscle, was an independent risk factor for OS (HR 0.98; 95% CI 0.97-1.00; p = 0.01) and CSS (HR 0.98; 95% CI 0.96-1.00; p < 0.05). The assessed adipose tissue indices were not significant predictors for OS and CSS. CONCLUSIONS: Sarcopenia, a low PMI, and myosteatosis are independent predictors for OS and CSS in patients undergoing radical cystectomy for bladder cancer.
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Radical nephroureterectomy (NUE) is the gold standard treatment for high-risk urothelial cancer of the upper urinary tract (UTUC). Besides sarcopenia and frailty, fat distribution is moving increasingly into focus. Components of body composition were assessed in patients undergoing NUE due to UTUC. The study cohort included 142 patients. By using CT-based measurements, the skeletal muscle index (SMI), subcutaneous adipose tissue index (SATI), and visceral adipose tissue index (VATI) were measured at the height of the third lumbar vertebra. Overall survival (OS) and cancer-specific survival (CSS) were estimated using univariable und multivariable Cox regression models. The prevalence of sarcopenia in the study population (n = 142) was 37%. OS and CSS were significantly reduced in sarcopenic patients. In the multivariable cox regression analysis, including age, ACE-27, T-stage, R-stage, LVI and necrosis, sarcopenia remained a significant risk factor of OS (HR, 1.77; 95% CI 1.02-3.07; p = 0.042) and CSS (HR, 2.17; 95% CI 1.18-3.99; p = 0.012). High visceral adipose tissue seems to be protective, although not statistically significant. Sarcopenia is a comorbidity-independent risk factor in patients who underwent NUE due to UTUC. Visceral fat represents a potentially protective factor. These results suggest that specific factors of body composition can be used for better risk stratification.
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Molecular analysis of disseminated tumour cells (DTC) may aid in predicting the course of the disease and response to therapies in individual patients. It has been shown in bladder cancer and many other cancer types that the presence of disseminated tumour cells or occult micrometastases in bone marrow or lymph nodes is associated with shorter survival. This type of analysis is particularly important for patients who have been declared disease-free after postsurgery histopathological and clinical imaging analysis. However, comprehensive molecular analysis of disseminated tumour cells is challenging due to the low amount of material and great heterogeneity of the disease. Therefore, currently the routine molecular analysis of these cells is hardly possible in daily clinical practice. Nevertheless, we see daily advances in clinical utility of analysis of cellular or cell-free liquid biopsy analytes taken before, during or after surgery. These advances will enable an integration of translational research workflows into clinical decision-making.
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Neoplasias da Bexiga Urinária , Intervalo Livre de Doença , Humanos , Linfonodos/patologia , Metástase Linfática/patologia , Micrometástase de Neoplasia/patologia , Neoplasias da Bexiga Urinária/patologiaRESUMO
BACKGROUND: Matrix metalloproteinases (MMPs) play a crucial role in tumour initiation, progression, and metastasis, including peritoneal carcinosis (PC) formation. MMPs serve as biomarkers for tumour progression in colorectal cancer (CRC), and MMP overexpression is associated with advanced-stage metastasis and poor survival. However, the molecular mechanisms of PC from CRC remain largely unclear. METHODS: We investigated the role of MMPs during peritoneal colonisation by CRC cell lines in a human ex vivo peritoneum model and in patient-derived CRC and corresponding PC samples. MMP2 and MMP9 were inhibited using the small-molecule inhibitors batimastat and the specific MMP2/9 inhibitor III. RESULTS: MMP2 and MMP9 were strongly upregulated in patient-derived samples and following peritoneal colonisation by CRC cells in the ex vivo model. MMP inhibition with batimastat reduced colonisation of HT29 and Colo205 cells by 36% and 68%, respectively (p = 0.0073 and p = 0.0002), while MMP2/9 inhibitor III reduced colonisation by 50% and 41%, respectively (p = 0.0003 and p = 0.0051). Fibronectin cleavage was enhanced in patient-derived samples of PC and during peritoneal colonisation in the ex vivo model, and this was inhibited by MMP2/9 inhibition. CONCLUSION: MMPs were upregulated in patient-derived samples and during peritoneal attachment of CRC cell lines in our ex vivo model. MMP2/9 inhibition prevented fibronectin cleavage and peritoneal colonisation by CRC cells. MMP inhibitors might thus offer a potential treatment strategy for patients with PC.
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BACKGROUND: Stromal signalling increases the lateral cell adhesions of prostate epithelial cells grown in 3D culture. The aim of this study was to use microarray analysis to identify significant epithelial signalling pathways and genes in this process. METHODS: Microarray analysis was used to identify genes that were differentially expressed when epithelial cells were grown in 3D Matrigel culture with stromal co-culture compared to without stroma. Two culture models were employed: primary epithelial cells (ten samples) and an epithelial cell line (three experiments). A separate microarray analysis was performed on each model system and then compared to identify tissue-relevant genes in a cell line model. RESULTS: TGF beta signalling was significantly ranked for both model systems and in both models the TGF beta signalling gene SOX4 was significantly down regulated. Analysis of all differentially expressed genes to identify genes that were common to both models found several morphology related gene clusters; actin binding (DIAPH2, FHOD3, ABLIM1, TMOD4, MYH10), GTPase activator activity (BCR, MYH10), cytoskeleton (MAP2, MYH10, TMOD4, FHOD3), protein binding (ITGA6, CD44), proteinaceous extracellular matrix (NID2, CILP2), ion channel/ ion transporter activity (CACNA1C, CACNB2, KCNH2, SLC8A1, SLC39A9) and genes associated with developmental pathways (POFUT1, FZD2, HOXA5, IRX2, FGF11, SOX4, SMARCC1). CONCLUSIONS: In 3D prostate cultures, stromal cells increase lateral epithelial cell adhesions. We show that this morphological effect is associated with gene expression changes to TGF beta signalling, cytoskeleton and anion activity.
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Morfogênese , Próstata/embriologia , Transdução de Sinais , Células Estromais/citologia , Regulação para Cima , Técnicas de Cultura de Células , Linhagem Celular , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Humanos , Masculino , Análise em Microsséries , Próstata/citologia , Próstata/metabolismo , Fatores de Transcrição SOXC/genética , Fatores de Transcrição SOXC/metabolismo , Células Estromais/metabolismo , Fator de Crescimento Transformador beta/metabolismoRESUMO
OBJECTIVE: To assess the true cumulative morbidity after RC by implementing the Comprehensive Complication Index (CCI) over a 90-day period, since recent evidence suggests underreporting of the cumulative morbidity after radical cystectomy (RC) with inconsistent complication rates when reported with conventional reporting systems. PATIENTS AND METHODS: Medical records of 433 patients with bladder cancer who underwent RC were retrospectively reviewed over a 90-day period. Clinical variables were assessed and complications were graded by the Clavien-Dindo Classification (CDC). The resulting 30- and 90-day CCI-scores were calculated and compared for each patient. Multivariable regression models for developing at least one severe (≥CDC IIIb) complication were designed. RESULTS: Overall, 848 complications were recorded in 371 patients (85.7%). Severe complications occurred in 130 patients (30%) and the cumulative morbidity corresponded to the level of a severe complication in 159 patients (36.7%), meaning an upgrade in 6.7% of patients compared to the CDC. The 90-day CCI (24.2 (median, IQR 20.9-39.7)) was higher than the 30-day CCI (22.6 (median, IQR 8.7-39.7)), (p < 0.001). Comorbidity indices (ASA, ACE 27), BMI, and incontinent urinary diversions were independent risk factors for suffering a severe complication within 90 days post-surgery. CONCLUSION: The cumulative morbidity (CCI) after RC seems to be higher than previously reported with CDC, especially over a 90-day period. The CCI is an appropriate assessment-tool with an upgrade in morbidity in a significant proportion of patients when compared to the CDC. BMI, several comorbidity indices, and incontinent urinary diversions are independent risk factors for suffering a severe complication after RC.
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Cistectomia , Complicações Pós-Operatórias/classificação , Neoplasias da Bexiga Urinária/cirurgia , Idoso , Feminino , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Fatores de TempoRESUMO
Autosomal dominant spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders. We investigated an SCA family from Serbia of Roma ethnic origin; four affected and nine unaffected family members underwent a detailed neurological examination. The presenting symptom in all patients was gait unsteadiness in early adulthood. Additional features included pyramidal signs, depression, and cognitive impairment. The condition follows an autosomal dominant pattern of inheritance. After excluding repeat expansions in nine known SCA genes, a genome-wide linkage analysis with 412 microsatellite markers localized the putative disease gene to a 40.7 cM (42.5 Mb) region on chromosome 15q between markers D15S1006 and D15S116. The maximum model-based multipoint LOD score was 1.75. This region is only 4.3 Mb away from the SCA11 (TTBK2) gene. Accordingly, mutations in TTBK2 were not found, suggesting a second SCA gene on chromosome 15q as cause of this novel form of SCA. In addition, we excluded alterations in two candidate genes in the linked region, namely expansion of a polyglutamine-coding CAG repeat in ARID3B and mutations in SEMA6D.
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Cromossomos Humanos Par 15/genética , Proteínas de Ligação a DNA/genética , Heterogeneidade Genética , Ataxias Espinocerebelares/genética , Adulto , Idoso , Saúde da Família , Feminino , Estudo de Associação Genômica Ampla/métodos , Humanos , Escore Lod , Masculino , Pessoa de Meia-Idade , Sérvia/epidemiologia , Sérvia/etnologia , Repetições de Trinucleotídeos/genéticaRESUMO
Although thousands of breast cancer cells disseminate and home to bone marrow until primary surgery, usually less than a handful will succeed in establishing manifest metastases months to years later. To identify signals that support survival or outgrowth in patients, we profile rare bone marrow-derived disseminated cancer cells (DCCs) long before manifestation of metastasis and identify IL6/PI3K-signaling as candidate pathway for DCC activation. Surprisingly, and similar to mammary epithelial cells, DCCs lack membranous IL6 receptor expression and mechanistic dissection reveals IL6 trans-signaling to regulate a stem-like state of mammary epithelial cells via gp130. Responsiveness to IL6 trans-signals is found to be niche-dependent as bone marrow stromal and endosteal cells down-regulate gp130 in premalignant mammary epithelial cells as opposed to vascular niche cells. PIK3CA activation renders cells independent from IL6 trans-signaling. Consistent with a bottleneck function of microenvironmental DCC control, we find PIK3CA mutations highly associated with late-stage metastatic cells while being extremely rare in early DCCs. Our data suggest that the initial steps of metastasis formation are often not cancer cell-autonomous, but also depend on microenvironmental signals.
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Interleucina-6/metabolismo , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Transdução de Sinais , Medula Óssea/patologia , Mama/citologia , Neoplasias da Mama/patologia , Classe I de Fosfatidilinositol 3-Quinases/genética , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Receptor gp130 de Citocina/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Feminino , Humanos , Interleucina-6/genética , Mutação , Metástase Neoplásica/genética , Receptores de Interleucina-6/deficiência , Receptores de Interleucina-6/metabolismo , Células Estromais/metabolismo , Microambiente TumoralRESUMO
Inhibition of gap junctional intercellular communication (GJIC) and the activation of intracellular mitogenic pathways are common hallmarks of epithelial derived cancer cells. We previously determined that the 1-methyl and not the 2-methyl isomer of anthracene, which are prominent cigarette smoke components, activated extracellular receptor kinase, and inhibited GJIC in WB-F344 rat liver epithelial cells. Using these same cells, we show that an immediate upstream response to 1-methylanthracene was a rapid (<1 min) release of arachidonic acid. Inhibition of phosphatidylcholine-specific phospholipase C prevented the inhibition of GJIC by 1-methylanthracene. In contrast, inhibition of phosphatidylinositol specific phospholipase C, phospholipase A(2), diacylglycerol lipase, phospholipase D, protein kinase C, and tyrosine protein kinases had no effect on 1-methylanthracene-induced inhibition of GJIC. Inhibition of protein kinase A also prevented inhibition of GJIC by 1-methylanthracene. Direct measurement of phosphatidylcholine-specific phospholipase C and sphingomyelinase indicated that only phosphatidylcholine-specific phospholipase C was activated in response to 1-methylanthracene, while 2-methylanthracene had no effect. 1-methylanthracene also activated p38-mitogen activated protein kinase; however, like extracellular kinase, its activation was not involved in 1-methylanthracene-induced regulation of GJIC, and this activation was independent of phosphatidylcholine-specific phospholipase C. Although mitogen activated protein kinases were activated, Western blot analyzes indicated no change in connexin43 phosphorylation status. Our results indicate that phosphatidylcholine-specific phospholipase C is an important enzyme in the induction of a tumorigenic phenotype, namely the inhibition of GJIC; whereas mitogen activated protein kinases triggered in response to 1-methylanthracene, were not involved in the deregulation of GJIC.
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Antracenos/toxicidade , Carcinógenos Ambientais/toxicidade , Junções Comunicantes/efeitos dos fármacos , Fosfolipases Tipo C/metabolismo , Animais , Antracenos/química , Comunicação Celular/efeitos dos fármacos , Linhagem Celular , Conexina 43/análise , Conexina 43/metabolismo , Conexinas/metabolismo , Inibidores Enzimáticos/farmacologia , Junções Comunicantes/química , Junções Comunicantes/metabolismo , Neoplasias/induzido quimicamente , Neoplasias/enzimologia , Fosforilação , Ratos , Fumaça , Esfingomielina Fosfodiesterase/análise , Esfingomielina Fosfodiesterase/metabolismo , Nicotiana/toxicidade , Fosfolipases Tipo C/antagonistas & inibidores , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
During September 16th-20th 2016, metastasis experts from around the world convened for the 16th Biennial Congress of the Metastasis Research Society and 12th National Congress of the Chinese Tumor Metastasis Society in Chengdu, China to share most current data covering basic, translational, and clinical metastasis research. Presentations of the more than 40 invited speakers of the main congress and presentations from the associated Young Investigator Satellite Meeting are summarized in this report by session topic. The congress program also included three concurrent short talk sessions, an advocacy forum with Chinese and American metastatic patient advocates, a 'Meet the Professors Roundtable' session for young investigators, and a 'Meet the Editors' session with editors from Cancer Cell and Nature Cell Biology. The goal of integrating expertise and exchanging the latest findings, ideas, and practices in cancer metastasis research was achieved magnificently, thanks to the excellent contributions of many leaders in the field.
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Oncologia , Metástase Neoplásica , Neoplasias/terapia , Relatório de Pesquisa , China , Humanos , Sociedades MédicasRESUMO
Sperm are highly differentiated and the activities that reprogram them for embryonic development during fertilization have historically been considered unique to the oocyte. We here challenge this view and demonstrate that mouse embryos in the mitotic cell cycle can also directly reprogram sperm for full-term development. Developmentally incompetent haploid embryos (parthenogenotes) injected with sperm developed to produce healthy offspring at up to 24% of control rates, depending when in the embryonic cell cycle injection took place. This implies that most of the first embryonic cell cycle can be bypassed in sperm genome reprogramming for full development. Remodelling of histones and genomic 5'-methylcytosine and 5'-hydroxymethylcytosine following embryo injection were distinct from remodelling in fertilization and the resulting 2-cell embryos consistently possessed abnormal transcriptomes. These studies demonstrate plasticity in the reprogramming of terminally differentiated sperm nuclei and suggest that different epigenetic pathways or kinetics can establish totipotency.
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Reprogramação Celular , Haploidia , Mitose/fisiologia , Espermatozoides/fisiologia , Animais , Desenvolvimento Embrionário , Feminino , Masculino , Camundongos , Partenogênese , Gravidez , Injeções de Esperma Intracitoplásmicas , ZigotoRESUMO
Bone is the most frequent site of metastasis in prostate cancer and patients with bone metastases are deemed incurable. Targeting prostate cancer cells that disseminated to the bone marrow before surgery and before metastatic outgrowth may therefore prevent lethal metastasis. This prompted us to directly analyze the transcriptome of disseminated cancer cells (DCC) isolated from patients with nonmetastatic (UICC stage M0) prostate cancer. We screened 105 bone marrow samples of patients with M0-stage prostate cancer and 18 bone marrow samples of patients without malignancy for the presence of EpCAM(+) single cells. In total, we isolated 270 cells from both groups by micromanipulation and globally amplified their mRNA. We used targeted transcriptional profiling to unambiguously identify DCCs for subsequent in-depth analysis. Transcriptomes of all cells were examined for the expression of EPCAM, KRT8, KRT18, KRT19, KRT14, KRT6a, KRT5, KLK3 (PSA), MAGEA2, MAGEA4, PTPRC (CD45), CD33, CD34, CD19, GYPC, SCL4A1 (band 3), and HBA2. Using these transcripts, we found it impossible to reliably identify true DCCs. We then applied combined genome and transcriptome analysis of single cells and found that EpCAM(+) cells from controls expressed transcripts thought to be epithelial-specific, whereas true DCCs may express hematopoietic transcripts. These results point to an unexpected transcriptome plasticity of epithelial cancer cells in bone marrow and question common transcriptional criteria to identify DCCs.
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Medula Óssea/metabolismo , Proteínas de Neoplasias/biossíntese , Neoplasias da Próstata/genética , Transcriptoma/genética , Adulto , Idoso , Antígenos de Neoplasias/genética , Medula Óssea/patologia , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Moléculas de Adesão Celular/genética , Molécula de Adesão da Célula Epitelial , Genoma Humano , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias da Próstata/patologia , RNA Mensageiro/biossínteseRESUMO
Because of the occurrence of different types of mutations, comprehensive genetic testing for Parkinson's disease (PD), dopa-responsive dystonia (DRD), and myoclonus-dystonia (M-D) should include screening for small sequence changes and for large exonic rearrangements in disease-associated genes. In diagnostic and research settings, the latter is frequently omitted or performed by laborious and expensive quantitative real-time PCR (qPCR). Our study aimed to evaluate the utility of a novel method, multiplex ligation-dependent probe amplification (MLPA), in molecular diagnostics of movement disorders. We have analyzed, by MLPA, genomic DNA from 21 patients affected with PD, DRD, or M-D, in which the presence of exon rearrangement(s) (n = 20) or of a specific point mutation (detectable by MLPA, n = 1) had been established previously by qPCR or sequencing. In parallel, we have studied, in a blinded fashion, DNA from 49 patients with an unknown mutational status. Exon rearrangements were evident in 20 samples with previously established mutations; in the 21st sample the known specific point mutation was detected. We conclude that MLPA represents a reliable method for large-scale and cost-effective gene dosage screening of various movement disorders genes. This finding reaches far beyond a simple technical advancement and has two major implications: (1) By improving the availability of comprehensive genetic testing, it supports clinicians in the establishment of a genetically defined diagnosis; (2) By enabling gene dosage testing of several genes simultaneously, it significantly facilitates the mutational analysis of large patient and control populations and thereby constitutes the prerequisite for meaningful phenotype-genotype correlations.
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Éxons , Rearranjo Gênico/genética , Transtornos dos Movimentos/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase/métodos , Humanos , Transtornos dos Movimentos/classificação , Reprodutibilidade dos TestesRESUMO
Dicumyl peroxide (di-CuOOH) and benzoyl peroxide (BzOOH) act as tumor promoters in SENCAR mice, whereas di-tert-butylhydroperoxide does not. Tumor promotion requires the removal of growth suppression by inhibition of gap junctional intercellular communication (GJIC) and the induction of mitogenic intracellular pathways. We showed that di-CuOOH and BzOOH both reversibly inhibited GJIC and transiently activated mitogen-activated protein kinase, specifically, the extracellular receptor kinase at noncytotoxic conditions in WB-F344 rat liver epithelial cells, whereas the non-tumor-promoting di-tert-butylhydroperoxide did not inhibit GJIC or activate extracellular receptor kinase. di-CuOOH but not BzOOH inhibited GJIC through a phosphatidylcholine-specific phospholipase C-dependent mechanism. N-acetylcysteine (NAC) was needed to prevent a cytotoxic, glutathione-depleting effect of BzOOH, whereas di-CuOOH was noncytotoxic and did not alter glutathione levels at all doses and times tested. Pretreatment of WB-F344 cells with resveratrol, a polyphenolic antioxidant present in red wine, prevented at physiological doses the inhibition of GJIC by di-CuOOH but not from BzOOH and was effective in significantly preventing extracellular receptor kinase activation by both peroxides. NAC did not prevent any of the peroxide effects on either GJIC or extracellular receptor kinase, suggesting a specific antioxidant effect of resveratrol.
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Anticarcinógenos/farmacologia , Comunicação Celular/efeitos dos fármacos , Junções Comunicantes/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oxidantes/farmacologia , Peróxidos/farmacologia , Estilbenos/farmacologia , Animais , Western Blotting , Relação Dose-Resposta a Droga , Células Epiteliais/enzimologia , Glutationa/metabolismo , Humanos , Fígado/citologia , Ratos , Ratos Endogâmicos F344 , Resveratrol , Fatores de TempoRESUMO
We present a mathematical algorithm for the analysis of electrophoretic patterns resulting from arbitrarily primed PCR profiling. The algorithm is based on the established mathematical procedures applied to the analysis of digital images of gel patterns. The algorithm includes (a) transformation of the image into a matrix form, (b) identification of every electrophoretic lane as a set of matrix columns that are further mathematically processed, (c) averaging of matrix columns corresponding to electrophoretic lanes that define lane representatives, (d) elimination of "smiling" bands, (e) solving the problem of a lane offset, and (f) removal of the background. Representation of individual electrophoretic lanes in the form of functions allows interlane comparisons and further mathematical analysis. Direct comparison of selected lanes was obtained by employing correlation analysis. Gel images were those obtained after arbitrarily primed PCR analysis of DNA that underwent damage induced by gamma radiation from a (60)Co source. The applied method proved to be useful for elimination of subjectivity of visual inspection. It offers the possibility to avoid overlooking important differences in case of suboptimal electrophoretic resolution. In addition, higher precision is achieved in the assessment of quantitative differences due to better insight into experimental artifacts. These simple mathematical methods offer an open-type algorithm, i.e., this algorithm enables easy implementation of different parameters that may be useful for other analytical needs.