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A R Brothman

Publications and source records attributed to A R Brothman.

At least 19 recordsLinked to original sources

Hypermethylation of the caveolin-1 gene promoter in prostate cancer.

BACKGROUND: Hypermethylation of CpG islands in the promoter regions of tumor suppressor genes is one mechanism of tumorigenesis. Caveolin-1 (Cav-1), a gene coding for the structural component of cellular caveolae, is involved in cell signaling and has been proposed to be a tumor suppressor gene in several malignancies. This gene maps to 7q31.1, a site known to be deleted in some prostate tumors. We chose to examine the methylation status of the promoter region of Cav-1 to determine whether this gene could function as a tumor suppressor in prostate cancer METHODS: Genomic DNA from both tumor and normal prostate epithelial cells was obtained from paraffin-embedded prostate sections by laser capture microdissection (LCM). The methylation status of 24 CpG sites at the 5' promoter region of Cav-1 was analyzed by bisulfite-direct-sequencing after amplification by PCR using primers specific for bisulfate modified DNA. Immunohistochemistry staining with a cav-1-specific antibody was also performed to evaluate the expression of the gene RESULTS: Twenty of the 22 (90.9%) informative cases showed promoter hypermethylation in the tumor cell population when compared with adjacent normal prostate cells with an average Methylation Index (potential frequency of total possible methylated Cs) from tumor cells equal to 0.426 vs. 0.186 for normal cells (P = 0.001). While no association with Gleason grade was found, overall increased methylation correlated with PSA failure (P = 0.016), suggestive of clinical recurrence. Elevated immunoreactivity with a Cav-1 antibody was observed in tumor cells from 7 of 26 prostate samples tested; this was associated with a Gleason score but not correlated with PSA failure or Methylation Index CONCLUSIONS: CpG sites at the 5' promoter of Cav-1 are more methylated in tumor than in adjacent normal prostate cells. Hypermethylation of the Cav-1 promoter supports the notion that Cav-1 may function as a tumor suppressor gene in prostate cancer and evidence is presented suggesting that methylation status of this gene is not only a marker for cancer but also may be predictive of outcome.

Aged↗

A common deletion at chromosomal region 17q21 in sporadic prostate tumors distal to BRCA1.

Prostate cancer is the most common cancer in males in the United States, yet the etiology of this disease is still poorly understood. In previous work from our laboratory, one or more deleted regions were found in prostate tumors distal to the breast and ovarian cancer susceptibility gene (BRCA1) on chromosome 17. This suggested that genes at 17q21 may play a pivotal role in prostate cancer progression, and there may be new tumor suppressor genes at this locus. We now present a physical map built with P1, P1 artificial chromosome, and bacterial artificial chromosome clones encompassing a DNA sequence anchored by multiple STS markers. The analysis of prostate tumors indicated an 85-kb novel commonly deleted interval flanked by D17S1184-D17S183-D17S1203-D17S1860, which is at least 470 kb distal to the BRCA1 gene. Fifty-four of 126 prostrate cancer cases (43%) showed a deletion by a direct FISH technique using P1 probes in this region. Searching with clone end sequences in the sequence database BLAST, the deleted clone covered genomic DNA sequence that contained upstream binding factor (UBF), EPB3 genes, SHCL1, ASB-4-like sequence, and acidic protein-like sequence. PCR for the ESTs confirmed that these genes or ESTs are within the deletion region. Our results will be helpful for finding candidate tumor suppressor genes in prostate cancer.

Chromosome Deletion↗

An apoptosis signaling pathway induced by the death domain of FADD selectively kills normal but not cancerous prostate epithelial cells.

The adaptor protein FADD directly, or indirectly via another adaptor called TRADD, recruits caspase 8 to death receptors of the tumor necrosis factor receptor family. Consequentially, a dominant-negative mutant (FADD-DN, which consists only of the FADD death domain) that binds to receptors but cannot recruit caspase 8 has been widely used to inhibit apoptosis by various stimuli that work via death receptors. Here, we show that FADD-DN also has another cell type- and cancer-dependent activity because it induces apoptosis of normal human prostate epithelial cells but not normal prostate stromal cells or prostate cancer cells. This activity is independent of FADD-DN's ability to bind to three known interacting proteins, Fas, TRADD or RIP suggesting that it is distinct from FADD's functions at activated death receptors. FADD-DN induces caspase activation in normal epithelial cells as demonstrated using a Fluorescence Resonance Energy Transfer assay that measures caspase activity in individual living cells. However, caspase-independent pathways are also implicated in FADD-DN-induced apoptosis because caspase inhibitors were inefficient at preventing prostate cell death. Therefore, the death domain of FADD has a previously unrecognized role in cell survival that is epithelial-specific and defective in cancer cells. This FADD-dependent signaling pathway may be important in prostate carcinogenesis.

Adaptor Proteins, Signal Transducing↗

Microdissection, DOP-PCR, and comparative genomic hybridization of paraffin-embedded familial prostate cancers.

There is a clear genetic component to prostate cancer susceptibility. Regions reported to be linked to prostate cancer include 1q24-25 (HPC-1), 1q42.2-43, and Xq27-28. There is limited genetic information on familial prostate tumors. We used the Utah Population Database to identify familial prostate cancer cases and selected 35 cases from high-risk families. Tissue blocks containing discernable tumor were available from 19 cases; 13 of these yielded adequate specimens for analysis. Six cases came from families with linkage to HPC-1, 3 were known to have linkage to Xq27-28, and 4 had no linkage to a known locus; 7 cases were analyzed from patients who showed no known linkage (sporadic tumors) as controls. These paraffin-embedded tumors were laser microdissected, degenerate oligonucleotide (DOP)-amplified, and labeled for fluorescence detection by comparative genomic hybridization (CGH). Loss of 7q, 10q, and 16q and gain of 8q were common abnormalities present in both familial and sporadic tumors. Distinctive abnormalities included loss of 3p12-3p22 in 3 of 6 HPC-7-linked cases and in 2 of 3 X-linked cases and gain of 6q11-6q21 in 2 each of HPC-1 and X-linked tumors. In conclusion, laser microdissection, DOP-PCR, and CGH is a feasible method for analysis of paraffin-embedded prostate tumors. This study provides preliminary data suggesting that familial prostate cancer harbors some unique genetic changes when compared with sporadic prostate tumors.

Chromosomes, Human, Pair 1↗

The BRCA2 genetic variant IVS7 + 2T-->G is a mutation.

Biochemical and genetic characterizations that support the conclusion that the variant BRCA2 IVS7 + 2T --> G represents a deleterious mutation are presented. RNA analysis from a breast cancer patient with BRCA2 IVS7 + 2T --> G showed that the productive message was produced from only one chromosome. A haplotype analysis confirmed that the intronic variant resides on the chromosome that does not produce the normal mRNA. Additionally, an RNA splicing product that deletes exon 7 was produced by the chromosome that carries BRCA2 IVS7 + 2T --> G. The deletion of exon 7 from the RNA alters the open reading frame by removing residues 249-287 and incorporating 18 abnormal amino acids before terminating with an opal stop codon. The experimental approach presented produces strong evidence of the presence of a deleterious mutation, because the contribution by both chromosomes to each RNA species analyzed was tracked using a coding region polymorphism as a marker. Furthermore, a single nucleotide polymorphism (SNP) haplotype analysis that confirms the location of the intronic variant and an associated family history that shows a high incidence of cancer supported these biochemical data.

5' Untranslated Regions↗

Nonrandom rearrangements of 6p in malignant hematological disorders.

It is very uncommon to observe nontranslocation abnormalities (NTAs) involving the short arm of chromosome 6 (6p) in malignant hematological disorders (MHDs). By using conventional cytogenetics and fluorescence in situ hybridization (FISH) with chromosome-microdissection probes specific for 6p21 and 6p25, we observed five patients with myeloid malignancies and two patients with lymphoid malignancies to have 6p NTAs. On the basis of our data and those in the literature, it is possible to divide 6p NTAs into the following three groups in MHD: The first group presents with 6p NTAs as a sole or primary change in myeloid malignancies. There are only two cases reported in this group, including one case with del(6)(p23) and the present case with ins(6)(q23p23p25) identified by FISH only. The second group presents with 6p deletions as a sole or primary change in lymphoid malignancies. Three cases have been reported in this group, including one case with del(6)(p21p23), one with del(6)(p21), and the present case 2 with del(6)(p21). The third group has 6p deletions in addition to other known primary changes, present in both myeloid and lymphoid disorders, with 36 cases reported, including five cases from our series. Deletions involving 6p21, 6p22, or 6p23 have been observed in both myeloid and lymphoid disorders. The present data provide cogent information for further molecular characterization of 6p anomalies in MHD.

Adult↗

Evidence by spectral karyotyping that 8q11.2 is nonrandomly involved in lipoblastoma.

We report two cases of lipoblastoma with chromosome 8-related aberrations, ie, a 92,XXYY,t(7;8Xp22;q11.2)x2 [8]/46,XY[16] in Case 1 and a 46,XY,-8,-13,add(16) (q22),+mar, +r [cp13]/46,XY[7] in Case 2. Using spectral karyotyping and fluorescence in situ hybridization techniques, the karyotype of Case 2 was redesignated as 46,XY, r(8), del(13)(q12), der(16)ins(16;8)(q22; q24q11.2)[cp13]/46,XY[7]. This report delineates a new chromosome rearrangement, ie, der(16)ins(16;8)(q22; q24q11.2) in lipoblastoma, and also confirms the t(7; 8)(p22;q11.2), reported only once previously, as a recurrent translocation involved in such a tumor. These findings provide valuable information for clinical molecular cytogenetic diagnosis of lipoblastoma. Furthermore, this report highlights the value of cytogenetic and molecular cytogenetic analysis in differential diagnosis of childhood adipose tissue tumors and adds to the number of lipoblastomas reported with chromosomal abnormalities at 8q11.2.

Chromosome Aberrations↗

Attenuated familial adenomatous polyposis in a man with an interstitial deletion of chromosome arm 5q.

Familial adenomatous polyposis (FAP) is an inherited colon cancer syndrome caused by mutations in the APC gene on chromosome region 5q21. Patients typically present with several hundred to several thousand polyps throughout the colon. Benign and malignant extracolonic manifestations are often present. Attenuated FAP (AFAP) is a recognized variant of FAP in which patients present with fewer than 100 polyps and appear to have a delayed onset of the clinical manifestations of FAP. Mutations in specific regions of the APC gene are associated with AFAP. A full deletion of the APC gene region has previously been thought to be associated with typical FAP. We now report on a 39-year-old man with a cytogenetically visible interstitial 5q deletion. Fluorescent in situ hybridization analysis with two cosmid probes specific for the 5' and 3' ends of the gene indicated that the entire APC locus is deleted. The number of polyps (50-60) seen in this patient was consistent with AFAP, as was the absence of multiple congenital hypertrophy of the retinal pigment epithelium (CHRPE). This is the first reported case of AFAP associated with a germline deletion of the entire APC gene.

Adenomatous Polyposis Coli↗

Chromosomal clues to the development of prostate tumors.

BACKGROUND: Cytogenetic, molecular cytogenetic, and molecular studies of prostate cancer have revealed an enormous amount of data regarding chromosomal loci that are aberrant in prostate tumors. METHODS: These data have been compared and condensed in this review to determine which chromosomes and chromosome sites have been most frequently reported. RESULTS: Loss of the Y chromosome, gain of 7, 8, and X, and interstitial deletions on 6q, 7q, 8p, 10q, 13q, 16q, 17q, and 18q are the most prevalent. CONCLUSIONS: A potential model for genetic control of tumor progression is presented, as are data regarding the evaluation of a new series of tumors.

Chromosome Aberrations↗

A group of previously not recognized cytogenetic abnormalities in myeloid hematological malignancies.

We have identified a group of previously not reported chromosome abnormalities related to myeloid hematological malignancies. Cases 1 and 2 were observed to have an additional i(4)(p10) as the sole anomaly with similar clinical features of myeloid disorders; that is, acute nonlymphocytic leukemia (ANLL-M2) and myelodysplastic syndrome (MDS)-refractory anemia with an excess of blasts in transformation, respectively. Fluorescence in situ hybridization studies with the use of a 4p-specific microdissection probe further confirmed the presence of an i(4)(p10) in these patients. Case 3 was diagnosed with ANLL-M1 and had an additional i(8)(p10) as the only change, also confirmed by a whole-chromosome painting procedure. In cases 4-6, deletions of 18q at breakpoints q12, q23, and q21 were identified as the sole anomaly in a myeloproliferative disorder (MPD), MPD, and MDS, respectively. X-autosome translocations other than t(X;10)(p11;p11) and t(X;11)(q13;q23) have not been reported as recurrent or primary changes in hematological disorders. In the present study, a t(X;9)(q26;q22) and t(X;5)(q13;q33) as the sole anomaly were found in cases 7 and 8, respectively. Both cases had the same diagnosis of MDS. Considering that trisomies 4 (+4) and 8 (+8) are common anomalies in MDS and ANLL, our findings strongly indicate that amplification of genes on 4p and 8p, but not on 4q and 8q, may play a crucial role in the pathogenesis of MDS and ANLL. In addition, genes on 18q12-23 and on Xq13-26 may be involved in the pathogenesis of myeloid disorders.

Adult↗

Partial trisomy 17p detected by spectral karyotyping.

We report the case of a child with partial trisomy of the short arm of chromosome 17, which was characterized by 24-color spectral karyotyping (SKY) and other fluorescence in situ hybridization (FISH) methods. The child had phenotypic features previously associated with trisomy 17p, including facial characteristics, developmental delay, postnatal growth retardation, single transverse crease, inguinal hernia, redundant neck skin folds, congenital heart defect, and club foot. This case illustrates the power of SKY for characterizing derivative/marker chromosomes in patients with rare cytogenetic syndromes.

Abnormalities, Multiple↗

Natural history of Wolf-Hirschhorn syndrome: experience with 15 cases.

Wolf-Hirschhorn syndrome (WHS) is a well-known chromosomal disorder attributable to partial deletion of the short arm of chromosome 4 (4p-). Although about 120 cases have been reported so far, there is still very little data on its natural history. Information given to parents at the time of diagnosis tends to be skewed to the extreme negative. To help delineate more thoroughly the natural history of WHS, and to obtain better information to answer parents' questions in a clinical setting, we evaluated 15 patients (12 females, 3 males) in three centers with the 4p- syndrome. Four of the cases had a follow-up spanning 16 years. Thirteen cases were detected by standard cytogenetics (regular G-banding 10, high-resolution banding 3), while the remaining 2 required fluorescence in situ hybridization. A total of 5/15 (33.3%) had heart lesions; 7/15 (46. 6%) had oral facial clefts; 13/15 (86.6%) had a seizure disorder, that tended to disappear with age; and 100% had severe/profound developmental retardation. One Italian patient had sensorineural deafness and 1 Utah patient had a right split hand defect. Of note, 2 Utah patients were able to walk with support (at 4 and 12 years of age, respectively), whereas 3 Italian patients and 1 Utah patient were able to walk unassisted (at 4, 5, 5 years 9 months, and 7 years of age, respectively). Two of the 3 Italian patients also achieved sphincter control (by day). The 8 patients receiving serial electroencephalogram studies showed fairly distinctive abnormalities, usually outlasting seizures. A slow, but constant progress in development was observed in all cases, during the follow-up period. In conclusion, the combined cases of the three centers represent considerable experience, providing new information on several aspects of this important deletion syndrome.

Adolescent↗

Extensive analysis of mosaicism in a case of Turner syndrome: the experience of 287 cytogenetic laboratories. College of American Pathologists/American College of Medical Genetics Cytogenetics Resource Committee.

OBJECTIVE: To assemble and interpret karyotype data provided as part of the College of American Pathologists/American College of Medical Genetics Cytogenetics Proficiency Testing Program. DATA SOURCES, EXTRACTION, AND SYNTHESIS: The Cytogenetics Resource Committee requested data on all cells analyzed in a 1994 whole-blood specimen challenge. In that study, 287 participating laboratories analyzed a total of 14297 cells derived from a sample drawn from an adult donor with Turner syndrome. This individual had previously been found to have mosaicism, including cell lines with X structural anomalies along with monosomy X, making this an excellent challenge for a multicenter cytogenetic survey. RESULTS AND CONCLUSIONS: Analysis of the data from this extensive study revealed mosaicism of up to 10 different sex chromosome complements involving the X chromosome with and without a small ring X or a derivative X chromosome. In the routine cytogenetic analysis performed by the participating laboratories, cell lines observed, in decreasing order of prevalence, included 45,X (n = 8357 cells), 46,X,r(X) (n = 3597), 46,X,der(X)t(X;X) (n = 2237), 46,XX (n = 93), 47,X,r(X),r(X) (n = 5), 47,X,der (X)t(X;X),der(X)t(X;X) (n = 3), 47,XX,r(X) (n = 2), and one observation each of 47,XX,der(X)t(X;X), 47,X,der(X)t (X;X),r(X), and 47,XXX. Our molecular cytogenetic data, as well as detailed analysis of G-banded chromosomes, suggest the nomenclature for these 2 abnormal X chromosomes as r(X)(p11.3q21.3) and der(X)t(X;X)(p11.3;q21.3), and we discuss models for the concomitant formation of these 2 entities. Both the degree of analysis and the extensive mosaicism that was discovered in this study are exceptional, and similar reported cases as well as possible mechanisms for the observed X chromosome instability are reviewed.

Adult↗

Variegated aneuploidy in two siblings: phenotype, genotype, CENP-E analysis, and literature review.

Cytogenetic studies of 2 sisters with mild microcephaly, growth deficiency, and mild errors of morphogenesis demonstrated a unique combination of multiple trisomies, most often involving chromosomes 8 and 18 either together as sole trisomies or in combination with other chromosomes. Since neither sib has phenotypic anomalies associated with trisomy 8 or 18 mosaicism, the trisomies likely did not occur during embryogenesis, but later possibly due to a predisposition for mitotic instability. To determine if the observed chromosome instability may be related to centromere function, metaphase cells were characterized by immunofluorescence of the centromere protein, CENP-E. Hybridization of CENP-E antibodies, in combination with in situ hybridization of a chromosome 8 or 18 alpha-satellite probe, showed hybridization to chromosomes 8 and 18 in both normal and aneuploid cells from each patient. These data indicate that the chromosomes in each child contain functional and active centromeres. The clinical and cytogenetic findings in these 2 individuals are compared with 7 other previously reported individuals, each of whom have similar findings. Together, these studies support the notion that a recessive mitotic mutant may be responsible for the chromosomal mosaicism and for the resulting clinical phenotype.

Centromere↗

Peripheral primitive neuroectodermal tumor presenting with diffuse cutaneous involvement and 7;22 translocation.

We report an unusual case of peripheral primitive neuroectodermal tumor (pPNET) in an infant presenting with congenital cutaneous nodules and a t(7;22)(p21;q11.2). The biologic behavior of the tumor diverged over time from a slowly growing tumor with multiple cutaneous nodules to a more aggressive neoplasm characterized by pulmonary metastases and a soft tissue mass showing additional cytogenetic alterations.

Chromosomes, Human, Pair 22↗

Chromosome 7 abnormalities in prostate cancer detected by dual-color fluorescence in situ hybridization.

Aneusomy of chromosome 7 and loss at 7q (especially 7q31.1) have been reported in prostate cancer. To further investigate abnormalities of 7q and the relationship with whole chromosome 7 changes, we have conducted a dual-color fluorescence in situ hybridization (FISH) analysis on isolated nuclei from 28 primary prostate cancers. A pericentromeric probe for chromosome 7, five newly isolated sequence-specific bacterial artificial chromosome (BAC) probes from 7q31.1, and one BAC for the epidermal growth factor receptor (EGFR) gene at 7p12 were used in dual color hybridizations. Pericentromeric probes for chromosomes X and 4 were also used as controls. Sixteen (57.1%) of the 28 tumors showed clonal aberrations. Nine of them were trisomy 7 and four were hypertetrasomy for chromosome 7. Deletions at 7q31.1 were found in two of the high grade tumors. With the exception of these two cases, all other cases showed concordant results using all probes. These findings confirm previous studies that aneusomy of 7 is associated with prostate cancer progression, and there may be a tumor suppressor gene (TSG) at 7q31.1 which is associated with tumor progression. In addition, our study indicates: (1) the deletion pattern of individual nuclei infers that deletions at 7q31.1 precede reduplications of chromosome 7; and (2) the amplification of EGFR was not detected at the DNA level, suggesting that activation of this oncogene may play a minor role in prostate cancer.

Aneuploidy↗

Commonly occurring loss and mutation of the MXI1 gene in prostate cancer.

One of the most common chromosomal abnormalities in prostate cancer involves loss of 10q22-qter. Rarely, a smaller deletion, involving 10q24-q25, has been observed, suggesting the presence of a tumor suppressor gene at this site. We previously demonstrated that the MXI1 gene maps to 10q24-q25 and is mutated in some tumors with cytogenetically detectable deletions of this locus. MXI1 encodes a basic-helix-loop-helix protein that suppresses the transcriptional activity of the MYC oncoprotein by competing for the common dimerization partner, MAX, and binding to identical DNA sites. Because more than 90% of prostate tumors contain no cytogenetic abnormality of 10q, the relevance of MXI1 loss and/or mutation to the vast majority of cases remains unclear. We prospectively evaluated prostate tumors for loss of MXI1 by fluorescence in situ hybridization (FISH) and cytogenetic techniques. Twenty-one of 40 tumors (53%) demonstrated loss of a single MXI1 allele as determined by FISH. Ten cases with cytogenetically normal 10qs, but with FISH-documented deletion of MXI1, were examined at the molecular level, and eight mutations were identified, albeit at low frequency. Five of the mutant proteins were unable to bind DNA in association with MAX. We conclude that MXI1 gene loss in prostate cancer is common and most frequently involves a cytogenetically undetectable deletion.

Basic Helix-Loop-Helix Proteins↗

Rare trisomy mosaicism diagnosed in amniocytes, involving an autosome other than chromosomes 13, 18, 20, and 21: karyotype/phenotype correlations.

In order to determine the significance of trisomy mosaicism of an autosome other than chromosomes 13, 18, 20, and 21, 151 such cases diagnosed prenatally through amniocentesis were reviewed. These rare trisomy mosaicism cases include 54 from 17 cytogenetic laboratories, 34 from a previous North American mosaicism survey, and 63 from published reports. All were cases of true mosaicism with information available on pregnancy outcome, and with no evidence of biased ascertainment. There were 11 cases of 46/47, +2; 2 of 46/47, +3; 2 of 46/47, +4; 5 of 46/47, +5; 3 of 46/47, +6; 8 of 46/47, +7; 14 of 46/47, +8; 25 of 46/47, +9; 2 of 46/47, +11; 23 of 46/47, +12; 5 of 46/47, +14; 11 of 46/47, +15; 21 of 46/47, +16; 7 of 46/47, +17; 1 of 46/47, +19; and 11 of 46/47, +22. As to the risk of an abnormal outcome, the data showed a very high risk (> 60 per cent) for 46/47, +2, 46/47, +16, and 46/47, +22; a high risk (40-59 per cent) for 46/47, +5, 46/47, +9, 46/47, +14, and 46/47, +15; a moderately high risk (20-39 per cent) for 46/47, +12; a moderate risk (up to 19 per cent) for 46/47, +7 and 46/47, +7 and 46/47, +8; a low risk for 46/47, +17; and an undetermined risk, due to lack of cases, for the remaining autosomal trisomy mosaics. Most cases were evaluated at birth or at termination, so subtle abnormalities may have escaped detection and developmental retardation was not evaluated at all. Comparison of the phenotypes of prenatally diagnosed abnormal cases and postnatally diagnosed cases with the same diagnosis showed considerable concordance. Since the majority of anomalies noted are prenatally detectable with ultrasound, an ultrasound examination should be performed in all prenatally diagnosed cases. In cytogenetic confirmation studies, the data showed much higher confirmation rates in cases with abnormal outcomes than in cases with normal outcomes [81 per cent vs. 55 per cent for fibroblasts (from skin, fetal tissue, and/or cord); 88 per cent vs. 46 per cent for placental cells; 22 per cent vs. 10 per cent for blood cells]. The confirmation rate reached 85 per cent when both fibroblasts and placental tissues were studied in the same case (with trisomic cells found in one or the other, or both). Therefore, one must emphasize that both fibroblasts and placental tissues should be studied. Except for 46/47, +8 and 46/47, +9, PUBS is of limited value for prenatal diagnosis of rate trisomy mosaicism. DNA studies for UPD are suggested for certain chromosomes with established imprinting effects, such as chromosomes 7, 11, 14, and 15, and perhaps for chromosomes 2 and 16, where imprinting effects are likely.

Adolescent↗