RESUMEN
BACKGROUND: Ataxia telangiectasia mutated (ATM) is a kinase that has a central role in the maintenance of genomic integrity by activating cell cycle checkpoints and promoting repair of DNA double-strand breaks (DSB). In breast cancer, a low level of ATM was correlated with poor outcome; however, the molecular mechanism of this downregulation is still unclear. METHODS: We used qRT-PCR assay to quantify mRNA levels of ATM gene in 454 breast tumours from patients with known clinical/pathological status and outcome; reverse phase protein arrays (RPPA) were used to assess the levels of ATM and 14 proteins in 233 breast tumours. RESULTS: ATM mRNA was associated with poor metastasis-free survival (MFS) (P=0.00012) on univariate analysis. ATM mRNA and protein levels were positively correlated (P=0.00040). A low level of ATM protein was correlated with poorer MFS (P=0.000025). ATM expression at mRNA or protein levels are independent prognostic factors on multivariate analysis (P=0.00046 and P=0.00037, respectively). The ATM protein level was positively correlated with the levels of six proteins of the DSB repair pathway: H2AX (P<0.0000001), XRCC5 (P<0.0000001), NBN (P<0.0000001), Mre11 (P=0.0000029), Rad50 (P=0.0064), and TP53BP1 (P=0.026), but not with proteins involved in other pathways that are altered in cancer. Low expression of ATM protein was significantly associated with high miR-203 expression (P=0.011). CONCLUSION: We confirmed that ATM expression is an independent prognostic marker at both RNA and protein levels. We showed that alteration of ATM is involved in dysregulation of the DSB repair pathway. Finally, miR-203 may be responsible for downregulation of ATM in breast cancers.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/genética , Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Carcinoma/genética , Roturas del ADN de Doble Cadena , Reparación del ADN , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/diagnóstico , Carcinoma/diagnóstico , Proteínas de Ciclo Celular/genética , Proteínas de Unión al ADN/genética , Regulación hacia Abajo , Femenino , Humanos , MicroARNs/genética , Persona de Mediana Edad , Pronóstico , ARN Mensajero/genética , Transducción de Señal/genéticaRESUMEN
Based on nationwide data from the French national cancer institute (INCa), we analyzed the evolution of cancer genetics consultations and testing over time, and the uptake of targeted tests in relatives of families with BRCA1/2 or MMR genes mutation. Genetic testing and consultations for familial high-risk individuals are exclusively funded and monitored by the INCa in France. All nationwide cancer genetics centers reported annually standardized parameters of activity from 2003 to 2011. The analysis included a total of 240,134 consultations and 134,652 genetic tests enabling to identify 32,494 mutation carriers. Referral for hereditary breast and ovarian cancer (HBOC) or colorectal cancer predisposition syndromes represented 59 % (141,639) and 23.2 % (55,698) consultations, respectively. From 2003 to 2011, we found a dramatic and steady increase of tests performed for BRCA1/2 (from 2,095 to 7,393 tests/year, P < 0.0001) but not for MMR genes (from 1,144 to 1,635/year, P = NS). The overall percentage of deleterious mutations identified in the probands tested was 13.8 and 20.9 % in HBOC and Lynch syndromes, respectively. Pooled analysis for BRCA1/2 and Lynch syndrome tests showed an inverse relationship between the percentage of mutation detected and the absolute number of tests performed over the time (overall Cochran-Armitage test for trend: P < 0.001). In families with BRCA1/2 or MMR identified mutations, there was an average number of 2.94 and 3.28 relatives performing targeted tests, respectively. This nationwide study shows a lack of referral and genetic testing in Lynch as compared to HBOC syndromes. Only a third of relatives of a proband with a predisposing mutation performed a targeted test. Enhanced information about benefit of genetic testing should be given to clinicians and patients for Lynch syndrome and relatives of a proband carrying an identified predisposing mutation.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/genética , Neoplasias de la Mama/genética , Neoplasias Colorrectales Hereditarias sin Poliposis/genética , Proteínas de Unión al ADN/genética , Genes BRCA1 , Genes BRCA2 , Asesoramiento Genético/estadística & datos numéricos , Pruebas Genéticas/estadística & datos numéricos , Proteína 2 Homóloga a MutS/genética , Síndromes Neoplásicos Hereditarios/genética , Proteínas Nucleares/genética , Neoplasias Ováricas/genética , Derivación y Consulta/estadística & datos numéricos , Neoplasias de la Mama/prevención & control , Instituciones Oncológicas/estadística & datos numéricos , Neoplasias Colorrectales Hereditarias sin Poliposis/prevención & control , Reparación de la Incompatibilidad de ADN/genética , Análisis Mutacional de ADN/estadística & datos numéricos , Salud de la Familia , Femenino , Francia , Tamización de Portadores Genéticos , Asesoramiento Genético/tendencias , Pruebas Genéticas/tendencias , Humanos , Laboratorios/estadística & datos numéricos , Masculino , Homólogo 1 de la Proteína MutL , Mutación , Síndromes Neoplásicos Hereditarios/prevención & control , Neoplasias Ováricas/prevención & control , Derivación y Consulta/tendenciasRESUMEN
BACKGROUND: The Hedgehog (Hh) signalling pathway functions as an organiser in embryonic development. Recent studies have shown constitutive activation of this pathway in various malignancies, but its role in bladder cancer remains poorly studied. METHODS: Expression levels of 31 genes and 9 microRNAs (miRNAs) involved in the Hh pathway were determined by quantitative real-time RT-PCR in 71 bladder tumour samples (21 muscle-invasive (MIBC) and 50 non-muscle-invasive (NMIBC) bladder cancers), as well as in 6 bladder cancer cell lines. RESULTS: The SHH ligand gene and Gli-inducible target genes (FOXM1, IGF2, OSF2, H19, and SPP1) were overexpressed in tumour samples as compared with normal bladder tissue. SHH overexpression was found in 96% of NMIBC and 52% of MIBC samples, as well as in two bladder cancer cell lines. Altered expression of miRNAs supported their oncogene or tumour-suppressor gene status. In univariate analysis, high expression levels of PTCH2, miRNA-92A, miRNA-19A, and miRNA-20A were associated with poorer overall survival in MIBC (P=0.02, P=0.012, P=0.047, and P=0.036, respectively). CONCLUSION: We observed constitutive activation of the Hh pathway in most NMIBC and about 50% of MIBC. We also found that some protein-coding genes and miRNAs involved in the Hh pathway may have prognostic value at the individual level.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Carcinoma de Células Transicionales/metabolismo , Proteínas Hedgehog/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Carcinoma de Células Transicionales/diagnóstico , Carcinoma de Células Transicionales/mortalidad , Estudios de Casos y Controles , Línea Celular Tumoral , Femenino , Expresión Génica , Proteínas Hedgehog/genética , Humanos , Estimación de Kaplan-Meier , Masculino , MicroARNs/genética , MicroARNs/metabolismo , Persona de Mediana Edad , Invasividad Neoplásica , Receptores Patched , Receptor Patched-2 , Pronóstico , Reacción en Cadena en Tiempo Real de la Polimerasa , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Transducción de Señal , Neoplasias de la Vejiga Urinaria/diagnóstico , Neoplasias de la Vejiga Urinaria/mortalidadRESUMEN
Hereditary breast cancers account for up to 5-10 % of breast cancers and a majority are related to the BRCA1 and BRCA2 genes. However, many families with breast cancer predisposition do not carry any known mutations for BRCA1 and BRCA2 genes. We explored the incidence of rare large rearrangements in the coding, noncoding and flanking regions of BRCA1/2 and in eight other candidate genes--CHEK2, BARD1, ATM, RAD50, RAD51, BRIP1, RAP80 and PALB2. A dedicated zoom-in CGH-array was applied to screen for rearrangements in 472 unrelated French individuals from breast-ovarian cancer families that were being followed in eight French oncogenetic laboratories. No new rearrangement was found neither in the genomic regions of BRCA1/2 nor in candidate genes, except for the CHEK2 and BARD1 genes. Three heterozygous deletions were detected in the 5' and 3' flanking regions of BRCA1. One large deletion introducing a frameshift was identified in the CHEK2 gene in two families and one heterozygous deletion was detected within an intron of BARD1. The study demonstrates the usefulness of CGH-array in routine genetic analysis and, aside from the CHEK2 rearrangements, indicates there is a very low incidence of large rearrangements in BRCA1/2 and in the other eight candidate genes in families already explored for BRCA1/2 mutations. Finally, next-generation sequencing should bring new information about point mutations in intronic and flanking regions and also medium size rearrangements.
Asunto(s)
Neoplasias de la Mama/genética , Genes BRCA1 , Genes BRCA2 , Predisposición Genética a la Enfermedad , Mutación de Línea Germinal , Adulto , Neoplasias de la Mama Masculina/genética , Hibridación Genómica Comparativa , Femenino , Humanos , Masculino , Persona de Mediana Edad , Linaje , Adulto JovenRESUMEN
BACKGROUND: It was shown recently on the level of gene expression that UGT8, coding UDP-galactose:ceramide galactosyltransferase, is one of six genes whose elevated expression correlated with a significantly increased the risk of lung metastases in breast cancer patients. In this study primary tumours and their lung metastases as well as breast cancer cell lines were analysed for UGT8 expression at the protein level. METHODS: Expression of UGT8 in breast cancer tissue specimens and breast cancer cell lines was analysed using IHC, real-time PCR and Western blotting. RESULTS: Comparison of the average values of the reaction intensities (IRS scale) showed a significant difference in UGT8 expression between (1) primary and metastatic tumours (Mann-Whitney U, P<0.05), (2) tumours of malignancy grades G3 and G2 (Mann-Whitney U, P<0.01) as well as G3 and G1 (Mann-Whitney U, P<0.001) and (3) node-positive and node-negative tumours (Mann-Whitney U, P<0.001). The predictive ability of increased expression of UGT8 was validated at the mRNA level in three independent cohorts of breast cancer patients (721). Similarly, breast cancer cell lines with the 'luminal epithelial-like' phenotype did not express or weakly expressed UGT8, in contrast to malignant, 'mesenchymal-like,' cells forming metastases in nude mice. CONCLUSION: Our data suggest that UGT8 is a significant index of tumour aggressiveness and a potential marker for the prognostic evaluation of lung metastases in breast cancer.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/genética , Carcinoma Ductal de Mama/genética , Balactosiltransferasa de Gangliósidos/genética , Neoplasias Pulmonares/genética , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/patología , Línea Celular Tumoral , Femenino , Expresión Génica , Humanos , Neoplasias Pulmonares/secundario , Persona de Mediana Edad , PronósticoRESUMEN
BACKGROUND: The TP53 pathway, in which TP53 and its negative regulator MDM2 are the central elements, has an important role in carcinogenesis, particularly in BRCA1- and BRCA2-mediated carcinogenesis. A single nucleotide polymorphism (SNP) in the promoter region of MDM2 (309T>G, rs2279744) and a coding SNP of TP53 (Arg72Pro, rs1042522) have been shown to be of functional significance. METHODS: To investigate whether these SNPs modify breast cancer risk for BRCA1 and BRCA2 mutation carriers, we pooled genotype data on the TP53 Arg72Pro SNP in 7011 mutation carriers and on the MDM2 309T>G SNP in 2222 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Data were analysed using a Cox proportional hazards model within a retrospective likelihood framework. RESULTS: No association was found between these SNPs and breast cancer risk for BRCA1 (TP53: per-allele hazard ratio (HR)=1.01, 95% confidence interval (CI): 0.93-1.10, P(trend)=0.77; MDM2: HR=0.96, 95%CI: 0.84-1.09, P(trend)=0.54) or for BRCA2 mutation carriers (TP53: HR=0.99, 95%CI: 0.87-1.12, P(trend)=0.83; MDM2: HR=0.98, 95%CI: 0.80-1.21, P(trend)=0.88). We also evaluated the potential combined effects of both SNPs on breast cancer risk, however, none of their combined genotypes showed any evidence of association. CONCLUSION: There was no evidence that TP53 Arg72Pro or MDM2 309T>G, either singly or in combination, influence breast cancer risk in BRCA1 or BRCA2 mutation carriers.
Asunto(s)
Neoplasias de la Mama/genética , Genes BRCA1 , Genes BRCA2 , Genes p53 , Predisposición Genética a la Enfermedad , Mutación , Polimorfismo de Nucleótido Simple , Proteínas Proto-Oncogénicas c-mdm2/genética , Neoplasias de la Mama/etiología , Femenino , Heterocigoto , Humanos , Factores de RiesgoRESUMEN
The somatic loss of heterozygosity for normal alleles occurring in human tumors has suggested the presence of recessive oncogenes. The results presented here demonstrate a loss of heterozygosity of several genes on chromosome 11 in primary breast tumors. Restriction fragment length polymorphism analysis of these DNAs further suggests that the most frequent loss of sequences in breast tumors occurs between the beta-globin and parathyroid hormone loci on the short arm of chromosome 11. The loss of heterozygosity for chromosome 11 loci has a significant association with tumors that lack estrogen and progesterone receptors, grade III tumors, and distal metastasis.
Asunto(s)
Neoplasias de la Mama/genética , Cromosomas Humanos Par 11 , Homocigoto , Alelos , Aberraciones Cromosómicas , Deleción Cromosómica , Mapeo Cromosómico , Femenino , Genes , Humanos , Proto-OncogenesRESUMEN
BACKGROUND: Many unclassified variants (UV) of BRCA1 or BRCA2 may have an effect on pre-mRNA splicing. Patient blood samples suitable for RNA extraction are not always available for testing UVs at the RNA level. METHODS: Analyses of RNA from patient peripheral blood were performed, using a one-step reverse transcriptase-PCR (RT-PCR) protocol, and were compared with an ex vivo splicing assay based on PCR-amplified patient DNA inserted into a splicing reporter minigene. Using both methods 20 variants found in 17 patients were examined. RESULTS: Data from patient RNA and from the minigene assay were fully concordant, but the ex vivo splicing assay, which is monoallelic, clarified several ambiguities in the patient RNA data. Two intronic variants induced strong splicing defects: BRCA1 c.4987-5T-->A (IVS16-5T-->A) induced exon 17 skipping and BRCA2 c.316+5G-->C (IVS3+5G-->C) induced complete skipping of exon 3. Of the exonic variants, BRCA2 c.7805G-->C (p.Arg2602Thr), at the last base of exon 16, induced both exon skipping and activation of a cryptic exonic donor site, and BRCA2 c.8023A-->G (p.Ile2675Val) generated a strong donor site within exon 18. These four variants were thus classified as pathogenic, because of the total absence of a normal transcript from the corresponding allele. Variant BRCA2 c.9501+3A-->T (IVS25+3A-->T) induced incomplete skipping of exon 25, suggesting a mutation with incomplete penetrance, and BRCA2 c.8257_8259del (p.Leu2753del) modified the alternative splicing of exons 17 and 18. CONCLUSIONS: We show that functional analysis using a splicing reporter minigene is sensitive and specific, and should be used for initial screening of potential splicing defects, especially when patient RNA is not readily available.
Asunto(s)
Neoplasias de la Mama/genética , Genes BRCA1 , Genes BRCA2 , Neoplasias Ováricas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Algoritmos , Empalme Alternativo , Femenino , Genes Reporteros , Predisposición Genética a la Enfermedad , Variación Genética , Humanos , Mutación , ARN Mensajero/química , ARN Mensajero/genéticaRESUMEN
BACKGROUND: Few germline BRCA2 rearrangements have been described compared with the large number of germline rearrangements reported in the BRCA1 gene. However, some BRCA2 rearrangements have been reported in families that included at least one case of male breast cancer. OBJECTIVE: To estimate the contribution of large genomic rearrangements to the spectrum of BRCA2 defects. METHODS: Quantitative multiplex PCR of short fluorescent fragments (QMPSF) was used to screen the BRCA2 gene for germline rearrangements in highly selected families. QMPSF was previously used to detect heterozygous deletions/duplications in many genes including BRCA1 and BRCA2. RESULTS: We selected a subgroup of 194 high risk families with four or more breast cancers with an average age at diagnosis of < or = 50 years, who were recruited through 14 genetic counselling centres in France and one centre in Switzerland. BRCA2 mutations were detected in 18.6% (36 index cases) and BRCA1 mutations in 12.4% (24 index cases) of these families. Of the 134 BRCA1/2 negative index cases in this subgroup, 120 were screened for large rearrangements of BRCA2 using QMPSF. Novel and distinct BRCA2 deletions were detected in three families and their boundaries were determined. We found that genomic rearrangements represent 7.7% (95% confidence interval 0% to 16%) of the BRCA2 mutation spectrum. CONCLUSION: The molecular diagnosis of breast cancer predisposition should include screening for BRCA2 rearrangements, at least in families with a high probability of BRCA2 defects.
Asunto(s)
Genes BRCA2 , Mutación de Línea Germinal/genética , Exones/genética , Femenino , Humanos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Eliminación de Secuencia/genéticaRESUMEN
The estrogen receptor alpha (ERalpha) plays a critical role in the pathogenesis and clinical behavior of breast cancer. To obtain further insights into the molecular basis of estrogen-dependent forms of this malignancy, we used real-time quantitative reverse transcription (RT)-PCR to compare the mRNA expression of 560 selected genes in ERalpha-positive and ERalpha-negative breast tumors. Fifty-one (9.1%) of the 560 genes were significantly upregulated in ERalpha-positive breast tumors compared with ERalpha-negative breast tumors. In addition to well-known ERalpha-induced genes (PGR, TFF1/PS2, BCL2, ERBB4, CCND1, etc.) and genes recently identified by cDNA microarray-based approaches (GATA3, TFF3, MYB, STC2, HPN/HEPSIN, FOXA1, XBP1, SLC39A6/LIV-1, etc.), an appreciable number of novel genes were identified, many of, which were weakly expressed. This validates the use of large-scale real-time RT-PCR as a method complementary to cDNA microarrays for molecular tumor profiling. Most of the new genes identified here encoded secreted proteins (SEMA3B and CLU), growth factors (BDNF, FGF2 and EGF), growth factor receptors (IL6ST, PTPRT, RET, VEGFR1 and FGFR2) or metabolic enzymes (CYP2B6, CA12, ACADSB, NAT1, LRBA, SLC7A2 and SULT2B1). Importantly, we also identified a large number of genes encoding proteins with either pro-apoptotic (PUMA, NOXA and TATP73) or anti-apoptotic properties (BCL2, DNTP73 and TRAILR3). Surprisingly, only a small proportion of the 51 genes identified in breast tumor biopsy specimens were confirmed to be ERalpha-regulated and/or E2-regulated in vitro (cultured cell lines). Therefore, this study identified a limited number of genes and signaling pathways, which better delineate the role of ERalpha in breast cancer. Some of the genes identified here could be useful for diagnosis or for predicting endocrine responsiveness, and could form the basis for novel therapeutic strategies.
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Neoplasias de la Mama/genética , Receptor alfa de Estrógeno/metabolismo , Regulación Neoplásica de la Expresión Génica , Proteínas de Neoplasias/genética , Biopsia , Neoplasias de la Mama/metabolismo , Estrógenos/farmacología , Femenino , Perfilación de la Expresión Génica , Humanos , Neoplasias Hormono-Dependientes/genética , Neoplasias Hormono-Dependientes/metabolismo , Análisis de Secuencia por Matrices de Oligonucleótidos , ARN Neoplásico/genética , ARN Neoplásico/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Tumorales Cultivadas/efectos de los fármacos , Células Tumorales Cultivadas/metabolismoRESUMEN
The Mitochondrial Tumor suppressor 1 (MTUS1) gene is a newly identified candidate tumor suppressor gene at chromosomal position 8p22. We report here that MTUS1 encodes a family of proteins whose leader member (ATIP1) was previously isolated in our laboratory as a novel interacting partner of the angiotensin II AT2 receptor involved in growth inhibition (Nouet, JBC 279: 28989-97, 2004). The MTUS1 gene contains 17 coding exons distributed over 112 kb of genomic DNA. Alternative exon usage generates three major transcripts (ATIP1, ATIP3 and ATIP4), each showing different tissue distribution. ATIP polypeptides are identical in their carboxy-terminal region carrying four coiled-coil domains. In their amino-terminal portion, ATIP polypeptides exhibit distinct motifs for localisation in the cytosol, nucleus or cell membrane, suggesting that MTUS1 gene products may be involved in a variety of intracellular functions in an AT2-dependent and independent manner. ATIP1 is ubiquitous and highly expressed in the brain. ATIP3 is the major transcript in tissues (prostate, bladder, breast, ovary, colon) corresponding to cancer types with frequent loss of heterozygosity at 8p22. Interestingly, ATIP4 is a brain-specific transcript highly abundant in the cerebellum and fetal brain. High evolutionary conservation of ATIP amino-acid sequences suggests important biological roles for this new family of proteins in tumor suppression and/or brain function.
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Genes Supresores de Tumor , Receptor de Angiotensina Tipo 2/metabolismo , Proteínas Supresoras de Tumor/genética , Empalme Alternativo , Secuencia de Bases , Northern Blotting/métodos , Sistema Nervioso Central/metabolismo , Mapeo Cromosómico , Cromosomas Humanos Par 8 , Evolución Molecular , Exones , Femenino , Expresión Génica , Variación Genética , Humanos , Intrones , Masculino , Familia de Multigenes/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , Análisis de Secuencia , Homología de Secuencia de Aminoácido , Distribución Tisular , Proteínas Supresoras de Tumor/química , Proteínas Supresoras de Tumor/metabolismoAsunto(s)
Poliposis Adenomatosa del Colon/genética , ADN Glicosilasas/genética , Reordenamiento Génico , Poliposis Adenomatosa del Colon/complicaciones , Poliposis Adenomatosa del Colon/etiología , Secuencia de Bases , Análisis Mutacional de ADN , Mutación de Línea Germinal , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Factores de RiesgoRESUMEN
The loss of heterozygosity of genes on the short arm of chromosome 3 (3p) in human breast carcinomas occurs in a region involved in other malignancies, including renal cell carcinoma, lung cancers, and von Hippel-Lindau disease. This finding suggests the presence of a gene(s) that plays a crucial role in multiple cancers. In our study of 84 informative (heterozygous) primary breast tumors, 30% showed losses of heterozygosity on chromosome 3. The shortest region of homozygosity in primary human breast tumor is located between the DNF15S2 and RAF1 loci in the 3p21-p25 region on the short arm of chromosome 3. This region includes at least two members of the c-erbA steroid/thyroid hormone receptor family (c-erbA beta and c-erbA2) that may be of special relevance to breast cancer. Furthermore, tumors with a loss of heterozygosity of genes on chromosome 3 were previously reported to have frequent allelic deletions on chromosome 11p and amplification of the c-myc proto-oncogene. These results highlight the occurrence of multiple genetic alterations in breast tumors.
Asunto(s)
Neoplasias de la Mama/genética , Carcinoma Intraductal no Infiltrante/genética , Deleción Cromosómica , Cromosomas Humanos Par 3 , ADN de Neoplasias/análisis , Proteínas Proto-Oncogénicas/análisis , Mapeo Cromosómico , Femenino , Genotipo , Humanos , Polimorfismo de Longitud del Fragmento de Restricción , Proto-Oncogenes Mas , Receptores de Hormona TiroideaRESUMEN
The c-Ha-ras-1 locus in 104 breast cancer patients and 56 unaffected individuals was examined for allelic restriction fragment-length polymorphism. Four common and 16 rare alleles were detected in the combined populations. The distribution of common and rare alleles differed significantly between the two populations. The common restriction fragments represented 91% of the allele pool in the unaffected population. In breast cancer patients, these common alleles represented only 59% of the allele pool (P less than .001). More specifically, the frequency of two of the common fragments, the 6.5- and 8.0-kilobase alleles, was significantly diminished in the breast cancer population (P less than .001 and P less than .02, respectively). The frequency of rare c-Ha-ras-1 alleles and hence genotypes composed of two rare alleles was increased in the breast cancer population (P less than .001). One of the rare alleles had a significant (P less than .05) association with these breast cancer patients. These results suggest that genotype analysis of the c-Ha-ras-1 locus, in combination with other clinical parameters, may be of prognostic value in assessing the potential for cancer.
Asunto(s)
Alelos , Neoplasias de la Mama/genética , Proto-Oncogenes , Adulto , Anciano , Femenino , Frecuencia de los Genes , Humanos , Persona de Mediana Edad , Proto-Oncogenes MasRESUMEN
Transforming growth factor alpha (TGF alpha) mRNA expression was measured by Northern blot analysis in 18 human, primary, infiltrating, ductal breast carcinomas. Expression of a 4.8-kilobase TGF alpha mRNA transcript was detected in nine of 18 tumors. No evidence was observed of any gross amplifications or major rearrangements of the TGF alpha gene in the breast carcinoma specimens. Biologically active and immunoreactive TGF alpha was measured in the pleural effusions or in the ascitic fluids from 37 noncancer and 63 cancer patients. The TGF alpha activity detected ranged from 0.2 to 26 ng/mL in most effusions from both groups. However, 29 of 63 (46%) of the effusions from cancer patients exhibited TGF alpha levels that were 6 ng/mL or higher, whereas only seven of 37 (19%) of those from noncancer patients exceeded this level (P less than .03). In particular, effusions obtained from breast cancer patients showed a significantly higher level of TGF alpha, compared with those from noncancer patients (P less than .001). Effusions from 14 cancer patients also contained elevated levels of two tumor-associated antigens, CEA and/or TAG-72, and within this group, nine also had elevated levels of TGF alpha.
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Neoplasias de la Mama/metabolismo , Carcinoma Intraductal no Infiltrante/metabolismo , ARN Mensajero/análisis , ARN Neoplásico/análisis , Factores de Crecimiento Transformadores/biosíntesis , Líquido Ascítico/metabolismo , Northern Blotting , Carcinoma Intraductal no Infiltrante/secundario , Femenino , Humanos , Metástasis Linfática , Derrame Pleural/metabolismo , Factores de Crecimiento Transformadores/genéticaRESUMEN
BACKGROUND: Clinical studies have shown that a marked lymphoplasmocytic reaction in breast tumors is associated with poor prognosis. Such findings raise the possibility that an inflammatory cell reaction might be a tumor-induced response that tends to promote tumor growth. PURPOSE: We assessed the expression of colony-stimulating factor-1 (CSF-1) as well as the prevalence of specific tumor-infiltrating lymphocytes and monocytes in breast tumors. METHODS: Tissue sections were obtained from archival paraffin blocks from 196 breast cancer patients. Seventy-eight percent of the women had been treated by mastectomy and 22% by lumpectomy. Median age of the patients was 54 years, and median follow-up was 7.3 years. Immunohistochemical and in situ hybridization techniques were used to characterize the specimens. RESULTS: Markedly high numbers of CD45RO-positive T- and L26-positive B-cell infiltrates were found in 13% and 17% of the tissue specimens, respectively. CSF-1 receptor-positive monocytes were detected in 48% and CD68-positive monocytes in 90% of the tumors. In turn, tumors with large fractions of CD68-positive monocytes also showed CSF-1 receptor-positive monocytes (P < .0001). CSF-1 was expressed significantly in 74% of the tumors and the CSF-1 receptor in more than 50% of the tumors. Tumors with high percentages of CSF-1 expressing cells also had marked monocyte infiltrates (P = .035). The presence of marked CD45RO-positive T-cell infiltrates and apparent nuclear staining of CSF-1 in tumor cells were associated with the more frequent occurrence of metastases (P = .02 and P = .04, respectively) and with poor survival (P = .02 and P = .03, respectively). CONCLUSIONS: Large numbers of CD45RO-positive (activated memory but noncytotoxic) T cells as well as a predominant nuclear staining pattern for CSF-1 are associated with a poor outcome in breast cancer patients. IMPLICATIONS: Nuclear retention of CSF-1 could reflect CSF-1 turnover and function in tumor cells, but new approaches are needed to establish the significance of these observations. Secreted CSF-1 appears to cause monocyte recruitment and activation, thereby modulating immune functions and potentially the expression of the CD45RO phenotype in T cells.
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Adenocarcinoma/inmunología , Neoplasias de la Mama/inmunología , Factor Estimulante de Colonias de Macrófagos/inmunología , Adenocarcinoma/patología , Adenocarcinoma/ultraestructura , Neoplasias de la Mama/patología , Neoplasias de la Mama/ultraestructura , Núcleo Celular/inmunología , Femenino , Humanos , Inmunohistoquímica , Inmunofenotipificación , Hibridación in Situ , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/fisiología , Factor Estimulante de Colonias de Macrófagos/fisiología , Persona de Mediana Edad , Invasividad Neoplásica , PronósticoRESUMEN
The breast cancer susceptibility gene BRCA2 is expressed in a wide range of tissues as an 11-kb mRNA transcript encoding a 3418-amino acid protein, which is involved in the response to DNA damage. To obtain a better molecular characterization of BRCA2 expression in breast tissue, we analyzed full-length BRCA2 mRNA by means of reverse transcriptase-PCR with a panel of primer pairs encompassing the entire cDNA sequence. We report the identification of an exon 12 alternatively spliced BRCA2 transcript (delta12-BRCA2) in normal human breast tissue, in a wide variety of other normal human tissues, and in several mouse tissues. The deletion observed in this transcript (96 bp) preserves the open reading frame, and translation of the transcript would result in a BRCA2 isoform lacking 32 amino acids between codons 2280 and 2311. The analysis of matched normal and primary tumor breast tissues from 12 patients showed that the expression level of the delta12-BRCA2 transcript was higher in 4 of 12 (33%) tumor tissues compared with their normal breast tissues. Overproduction of the delta12-BRCA2 variant was associated with steroid receptor-negative tumors (P = 0.0005). These data suggest that the mechanisms generating the BRCA2 mRNA variant exist in normal breast tissue and may be dysregulated in steroid receptor-negative breast tumor tissues.
Asunto(s)
Empalme Alternativo , Neoplasias de la Mama/metabolismo , Mama/metabolismo , Proteínas de Neoplasias/metabolismo , Factores de Transcripción/metabolismo , Proteína BRCA1/metabolismo , Proteína BRCA2 , Exones , Femenino , Humanos , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Receptores de Estrógenos/metabolismo , Receptores de Progesterona/metabolismoRESUMEN
To investigate the possibility of collaboration between telomeric deletion on the short arm of chromosome 1 and genetic amplification similar to that described in human neuroblastoma, 122 human primary breast tumors were examined by restriction fragment length polymorphism analysis for loss of heterozygosity on 1p32-pter and for the three most frequently amplified genetic regions in breast carcinomas (MYC and ERBB2 protooncogenes and the chromosomal region 11q13). Allelic losses at one or more loci on the telomeric part of the short arm of chromosome 1 was observed in 57 (47%) of 122 informative tumors. MYC, ERBB2, and the 11q13 region were amplified in 23, 20, and 21% of breast tumors, respectively. A correlation was found between loss of heterozygosity on chromosome 1p32-pter and amplification of the MYC (formerly c-myc) protooncogene (P = 0.003), suggesting that these two genetic events may collaborate during tumor progression in human breast cancer. These results, together with those obtained in human neuroblastoma, suggest that the distal part of the short arm of chromosome 1 harbors an unidentified tumor suppressor gene(s), whose inactivation may be involved in MYC family gene amplification (an example of genetic instability) in tumors of various cellular origins.
Asunto(s)
Neoplasias de la Mama/genética , Cromosomas Humanos Par 1 , Eliminación de Gen , Genes Supresores de Tumor/fisiología , Genes myc/genética , Proto-Oncogenes/genética , Femenino , Marcadores Genéticos , Humanos , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
We have examined the long arm of chromosome 17 in sporadic breast carcinomas for the loss of heterozygosity (LOH) at 18 polymorphic loci. At least three distinct regions could be identified by the frequency of LOH and confirmed by high density deletion maps of individual tumor DNAs. A proximal region affected by LOH is located in a 22-cM region defined by D17S73 and NME1 and thus is similar in location to the region thought to contain the BRCA1 gene associated with familial breast and breast/ovarian cancer. The central region affected by LOH is bordered by the D17S86 and D17S21 loci and is estimated to be 28 cM in size. The third region is bordered by the D17S20 and D17S77 loci which are 11 cM apart. These results define three independent regions of chromosome 17q which are likely to contain tumor suppressor genes relevant to the etiology of sporadic breast carcinoma.
Asunto(s)
Neoplasias de la Mama/genética , Deleción Cromosómica , Cromosomas Humanos Par 17 , Femenino , Humanos , Mapeo RestrictivoRESUMEN
Loss of heterozygosity (LOH) on chromosome arm 16q is one of the most consistent genetic alterations in sporadic prostate cancer and may be involved in cancer development through inactivation of tumor suppressor genes. A candidate tumor suppressor gene on this chromosome arm, CDH1 at 16q22.1, is dysregulated in prostate cancer. However, no specific deletion map has been constructed from prostate tumors to determine whether CDH1 is the potential target gene for the observed LOH on 16q. To narrow down the region of 16q loss, we constructed a detailed deletion map that incorporates CDH1. We examined the pattern of allelic imbalance in prostate tissue from 22 patients with confined prostate tumors, 22 with local extracapsular extension, and 15 with metastatic forms, using 14 CA microsatellite repeats on 16q. Thirty-five of the 59 tumors tested showed LOH for at least one marker. We found evidence of 16q monosomy in 5 cases and partial allelic loss in 30. Our data provide evidence that three different target regions on 16q might be involved in the pathogenesis of prostate cancer. The first region is telomeric and lies at 16q24.3 between markers D16S520 and D16S413; the second, the most centromeric region in the 16q22.1 band, and limited by markers D16S347 and D16S318, is close to the CDH1 gene; the third, intermediate region, at 16q23.2, is bracketed by loci D16S518 and D16S507. The rate of LOH at 16q24.3 was significantly higher in metastatic forms (80%; 12 of 15) than localized forms (32%; 7 of 22), pointing to a gene related to invasiveness in prostate cancer.