DNA amplifications at 20q13 and MDM2 define distinct subsets of evolved breast and ovarian tumours

DNA amplification seems to be particularly frequent in human breast tumours and has been associated with cancer evolution and aggressiveness. Recent data indicate that new events should be added to the list, such as the amplifications at chromosome 20q13 or the MDM2 gene. The present work aimed at determining the incidence and clinicopathological signification of these amplifications in a large series of breast and ovarian tumours. We tested 1371 breast and 179 ovarian tumours by Southern blotting and observed amplification of 20q13 in 5.4% breast and 2.8% ovarian carcinomas, whereas MDM2 was found amplified in 5.3% and 3.8% of breast and ovarian tumours respectively. MDM2 RNA expression levels were analysed in a subset of 57 breast tumours and overexpression was observed in 4/57 (7%) of the tumours. Elevated expression levels coincided with amplification of the gene. In breast cancer, 20q13 and MDM2 amplifications seem to define subsets of aggressive tumours. Indeed, 20q13 was correlated to axillary nodal involvement and occurred preferentially in younger patients (< 50 years). Furthermore, 20q13 correlated, as did MDM2 amplification, to aneuploidy. In parallel, we had also tested our tumour DNAs for amplification of CCND1, ERBB-2 and MYC, which made it possible to test for correlations with 20q13 or MDM2 amplifications. Whereas 20q13 showed a very strong correlation to CCND1 amplification, that of MDM2 was prevalent in MYC-amplified tumours. Interestingly, 20q13 and MDM2 amplifications showed some degree of correlation to each other, which may possibly be owing to the fact that both events occurred preferentially in aneuploid tumours. In ovarian cancer, no statistically significant correlation was observed. However, 20q13 amplification occurred preferentially in stage 3 tumours and MDM2 was correlated to ERBB-2 amplification. This may suggest that in ovarian tumours also, 20q13 and MDM2 amplifications occur in late or aggressive cancers.     

Mapping of chromosomal gains and losses in primitive neuroectodermal tumors by comparative genomic hybridization

Pediatric fungal pulmonary infections are being seen with increasing frequency. The dimorphic fungi Histoplasma capsulatum. Blastomyces dermatitidis, Coccidioides immitis, and Cryptococcus neoformans frequently cause infections that are asymptomatic. However, patients may suffer pneumonia and disseminated disease. Diagnosis can be made definitively by isolation of the causative organism, but serology or skin testing is often necessary when this is not successful. Severe or life threatening infections are treated with amphotericin B. Recently, new oral azole antifungals are being used more frequently for mild to moderate disease with good success.     

DNA copy number amplifications in human neoplasms: review of comparative genomic hybridization studies

This review summarizes reports of recurrent DNA sequence copy number amplifications in human neoplasms detected by comparative genomic hybridization. Some of the chromosomal areas with recurrent DNA copy number amplifications (amplicons) of 1p22-p31, 1p32-p36, 1q, 2p13-p16, 2p23-p25, 2q31-q33, 3q, 5p, 6p12-pter, 7p12-p13, 7q11.2, 7q21-q22, 8p11-p12, 8q, 11q13-q14, 12p, 12q13-q21, 13q14, 13q22-qter, 14q13-q21, 15q24-qter, 17p11.2-p12, 17q12-q21, 17q22-qter, 18q, 19p13.2-pter, 19cen-q13.3, 20p11.2-p12, 20q, Xp11.2-p21, and Xp11-q13 and genes therein are presented in more detail. The paper with more than 150 references and two tables can be accessed from our web site http://www.helsinki.fi/lglvwww/CMG.html. The data will be updated biannually until the year 2001.     

Comparison of estrogen receptor DNA binding in untreated and acquired antiestrogen-resistant human breast tumors

Preliminary studies have suggested that measuring the ability of immunoreactive 67-kDa estrogen receptor (ER) to bind DNA and form in vitro complexes with its cognate estrogen response element (ERE) might serve to identify breast tumors most likely to respond to antiestrogens like tamoxifen. Data from two different surveys of untreated primary breast tumors confirmed that only 67% (74 of 111) of ER-positive tumors express a receptor capable of forming ER-ERE complexes by gel-shift assay, with tumors of lower ER content having significantly reduced ER DNA-binding frequency (56%) relative to those of higher ER content (82%; P = 0.007). In contrast to these untreated tumors, a panel of 41 receptor-positive breast tumors excised after acquiring clinical resistance to tamoxifen during either primary (n = 26) or adjuvant therapy (n = 15) showed a significantly greater ER DNA-binding frequency, with nearly 90% capable of forming ER-ERE complexes (P < 0.02). To assess experimentally whether ER DNA-binding function is altered during the development of antiestrogen resistance, nude mouse MCF-7 tumor xenografts were analyzed before and after the acquisition of in vivo resistance to either tamoxifen or a pure steroidal antiestrogen, ICI 182,780. Tamoxifen-resistant MCF-7 tumors retained full expression of 67-kDa DNA-binding ER, and despite a markedly reduced ER content in the ICI 182,780-treated tumors, the expressed ER in these antiestrogen-resistant tumors exhibited full ability to form ER-ERE complexes. These findings indicate that breast tumors with acquired antiestrogen resistance continue to express ER of normal size and DNA-binding ability and suggest that the failure of antiestrogens to arrest tumor growth during emergence of clinical resistance results from an altered gene-regulatory mechanism(s) other than ER-ERE complex formation.     

Mapping an initiation region of DNA replication at a single-copy chromosomal locus in Drosophila melanogaster cells by two-dimensional gel methods and PCR-mediated nascent-strand analysis: multiple replication origins in a broad zone

We have mapped an initiation region of DNA replication at a single-copy chromosomal locus in exponentially proliferating Drosophila tissue culture cells, using two-dimensional (2D) gel replicon mapping methods and PCR-mediated analysis of nascent strands. The initiation region was first localized downstream of the DNA polymerase alpha gene by determining direction of replication forks with the neutral/alkaline 2D gel method. Distribution of replication origins in the initiation region was further analyzed by using two types of 2D gel methods (neutral/neutral and neutral/alkaline) and PCR-mediated nascent-strand analysis. Results obtained by three independent methods were essentially consistent with each other and indicated that multiple replication origins are distributed in a broad zone of approximately 10 kb. The nucleotide sequence of an approximately 20-kb region that encompasses the initiation region was determined and searched for sequence elements potentially related to function of replication origins.     

Mapping specific protein-protein interactions within the core component of the breast cell DNA synthesome

We have previously described the isolation and characterization of an intact multiprotein complex for DNA replication, designated the DNA synthesome, from human breast cancer cells and biopsied human breast tumor tissue. The purified DNA synthesome was observed to fully support DNA replication in vitro. We had also proposed a model for the breast cell DNA synthesome, in which DNA polymerases alpha, delta, and epsilon, DNA primase, and replication factor C (RF-C) represent members of the core component, or tightly associated, proteins of the complex. This model was based on the observed fractionation, chromatographic, and sedimentation profiles for these proteins. We report here that poly(ADP-ribose)polymerase (PARP) and DNA ligase 1 are also members of the breast cell DNA synthesome core component. More importantly, in this report we present the results of coimmunoprecipitation studies that were designed to map the protein-protein interactions between several members of the core component of the DNA synthesome. Consistent with our proposed model for the breast cell DNA synthesome, our data indicate that DNA polymerases alpha and delta, DNA primase, RF-C, as well as proliferating cell nuclear antigen (PCNA), tightly associate with each other in the complex, whereas DNA polymerase epsilon, PARP, and several other components were found to interact with the synthesome via a direct contact with only PCNA or DNA polymerase alpha. The association of PARP with the synthesome core suggests that this protein may serve a regulatory function in the complex. Also, the coimmunoprecipitation studies suggest that the three DNA polymerases alpha, delta, and epsilon all participate in the replication of breast cell DNA. To our knowledge this is the first report ever to describe the close physical association of polypeptides constituting the intact human breast cell DNA replication apparatus.     

Mapping of chromosomal imbalances in pancreatic carcinoma by comparative genomic hybridization

To identify recurrent chromosomal imbalances in pancreatic adenocarcinoma, 27 tumors were analyzed by using comparative genomic hybridization. In 23 cases chromosomal imbalances were found. Gains of chromosomal material were much more frequent than losses. The most common overrepresentations were observed on chromosomes 16p (eight cases), 20q (seven cases), 22q (six cases), and 17q (five cases) and under-representations on a subregion of chromosome 9p (eight cases). Distinct high-level amplifications were found on 1p32-p34, 6q24, 7q22, 12p13, and 22q. These data provide evidence for a number of new cytogenetically defined recurrent aberrations which are characteristic of pancreatic carcinoma. The overrepresented or underrepresented chromosomal regions represent candidate regions for potential oncogenes and tumor suppressor genes, respectively, possibly involved in pancreatic tumorigenesis.     

DNA damage induced by UV light affects restriction endonuclease recognition sites: correlation between effects at chromosomal level and naked DNA

Optimal management of patients with the antiphospholipid syndrome (APS) remains a problem. There is now good evidence that those with thrombosis will be subject to recurrences and require long-term, possibly lifelong, oral anticoagulation. Steroids and immunosuppressive drugs aiming at a reduction of the antibody levels have not provided long-term benefit. Only prospective and controlled clinical trials can give a definitive answer to the optimal thrombotic prophylaxis in patients with the APS.     

Association of a host DNA structure with retroviral integration sites in chromosomal DNA

Integration of retroviral genomes is a site-specific process with respect to the virus but not the host genome. Numerous chromosomal sites and various sequences can be used as targets. Nevertheless, preferential regions and integration patterns have been observed. Using a functional assay, we investigated if host structural DNA elements could be associated with retroviral integration sites. The results were that 9 of 10 distinct retroviral integration events occurred in close proximity of structural elements behaving like intrinsically bent DNA.     

Structural and functional abnormalities at 11p15 are associated with the malignant phenotype in sporadic adrenocortical tumors: study on a series of 82 tumors

Abnormalities of the 11p15 region with overexpression of the normally imprinted insulin-like growth factor II (IGF-II) gene have been implicated in the pathogenesis of adrenocortical tumors. We evaluated the frequency and distribution of 11p15 loss of heterozygosity (LOH) and IGF-II gene overexpression in a series of 82 sporadic adrenocortical tumors, screened for pathological functional imprinting of the 11p15 region in tumors not exhibiting LOH and evaluated the expression of H19 gene in these tumors. Abnormalities of the 11p15 region as LOH (loss of the maternal allele and duplication of the paternal allele) and/or IGF-II gene overexpression are frequent features of the malignant state and were found in 27 of 29 (93.1%) of the malignant tumors and in only 3 of 35 (8.6%) of the benign tumors. Tumors without abnormality of the 11p15 region (mainly benign tumors) did not exhibit pathological functional imprinting. In tumors with mosaicism for 11p15 LOH, biallelic expression of the IGF-II gene was constant in the tumor cell contingent not undergoing LOH. Abrogation of H19 expression correlated with the loss of the maternal allele (LOH or pathological imprinting), but did not always correlate with overexpression of the IGF-II gene. These data indicate the involvement of dysregulation of the 11p15 region in late steps of adrenocortical tumorigenesis and provide us with new molecular markers for a better diagnostic and prognostic evaluation of adrenocortical tumors.     

Hormonal sensitivity of human breast tumors in vitro: pentose-shunt activity

Recent studies indicated that response to endocrine therapy might be predicted in human breast carcinomas using the sensitivity of the pentose-shunt pathway to hormones in organ culture. Thirty breast tumors were examined using this histochemical method, and three independent assessments were made. There was poor agreement between the observers, and we consider that this test is not reproducible in its present form.     

Cytogenetic and phenotypic effects of a chromosomal rearrangement involving the Z-chromosome and micro-chromosome in the chicken

Measurements demonstrated that the Z-chromosome was truly metacentric. Forty-six percent of one arm of a female's Z-chromosome had been translocated to a microchromosome (Z-micro) by irradiation of semen. The bread was 23 crossover units distal to the late feathering (K) locus. The barring (B) locus on the non-broken arm assorted almost independently of the Z-micro segment. Semen from eight sons of this Z-micro female was used to inseminate 98 dwarf (dw) broiler-type females. From karyotypes of 147 male and 149 female progeny, we identified 69 males heterozygous and 79 females hemizygous for Z-micro. Body weight of 43 males heterozygous for Z-micro was significantly greater than that of 45 normal Z paternal half-brothers at all ages from 2 to 24 weeks. In contrast, body weight of 57 Z-micro females compared with their 56 normal Z paternal half-sisters was depressed significantly at 2, 4, and 6 weeks but not significantly at 8, 12, 16, and 24 weeks of age. Age at first egg was retarded 8 days and egg production over a 153 day test period was reduced 19.6%, primarily due to a reduction of egg laying sequence from 2.7 to 2.1 days in the Z-micro females.     

The field of clinical psychology: Arriving at a definition.

Summarizes the development of the definition of the field of clinical psychology by the Executive and members of the Section on Clinical Psychology of the Canadian Psychological Association. The need for a definition and the process of drafting the definition are highlighted. Strategies for the use of the definition in advancing the field of clinical psychology are also addressed. The definition of clinical psychology is appended. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of an antigen containing 3-hydroxyanthranilic acid in the sera of patients with tumors of different localizations]

An unusual antigen containing a carcinogenic tryptophane metabolite -- 3-hydroxyanthranylic acid as a hapten (3-HAA-antigen) was found to be present in the blood serum in the overwhelming majority of patients with malignant tumours of various stages and localizations. The 3-HAA-antigen was rarely determined in the patients with nonmalignant diseases was not revealed in the blood serum of healthy donors and patients with benign tumours. The significance of the data obtained for the diagnosis of the tumour process, irrespective of its localization, is discussed.     

A chromosomal analysis of the phenotypic plasticity of some life history traits in relation to developmental temperature

The capacity to delay egg deposition in D. melanogaster females in the absence of a sexual partner is genetically determined and opposite types can be artificially selected. In natural populations, the relative frequency of these genotypes varies geographically and seasonally, with temperature as a selective factor. However, the retention duration of these genotypes can be modified by developmental temperature change. To study the genetic control of this response, chromosome substitution between opposite types of line was carried out in order to produce every possible homozygous chromosomal combination of the three major chromosomes (X,2,3). Eggs of these eight constructed lines were developed at two different temperatures (25 degrees C and 14 degrees C). Low temperature development directly affected the number of ovarioles but also modified the subsequent expression of adult characteristics such as retention duration and fecundity. The comparison of the eight lines revealed that, although the 3 chromosomes were involved in the genetic determinism of each trait, only one or two of them were sensitive to temperature change, and these differed according to the trait. For retention duration and fecundity, the effect of chromosome 3 from the long retention strain was particularly affected by low temperature, showing antagonism between the selective effect detected in natural populations and the effect on phenotypic plasticity studied here.     

Karyotypic changes in phyllodes tumors of the breast

Cytogenetic analysis of short-term cultures of five phyllodes tumors of the breast-classified as benign (one tumor), borderline malignant (two tumors removed from the same breast in 1991 and 1993), and malignant (two tumors)--revealed clonal changes with simple structural abnormalities in the benign tumor, the borderline malignant tumors, and one malignant tumor in which benign areas and areas of borderline malignancy were also present. In contrast, the malignant tumor without admixed borderline malignant or benign areas had a complex karyotype. The karyotype of the benign phyllodes tumor was 46,XX,del(12)(p11p12)/46,XX,t(8;18)(p11;p11)/46,XX. The first borderline malignant phyllodes tumor had t(3;20)(p21;q13) as the sole abnormality. When the tumor recurred, this was no longer the only clone detected and the tumor karyotype was now 46,XX,t(3;20)(p21;q13)/46,XX,t(9;10)(p22;q22)/46,XX,t(1;8) (p34;q24)/46,XX,del(11)(q22-23)/46,XX. The malignant/borderline malignant/benign tumor had t(1;6)(p34;p22) as the sole clonal abnormality. Finally, the karyotype of the malignant phyllodes tumor which contained no benign or borderline malignant areas was 42,XX,der(1)t(1;4)(q21;q21),der(3)t(3;17)(q29;q21), -4,i(8)(q10), -10, -13,i(13)(q10),der(14)t(1;14)(q21;p11),der(14)t(4;14) (p12;p11), -17/80-90,idemx2, +del(1)(q12), +i(1)(p10), +dic(5;5)(p14;p14), +i(6)(p10), +del(7)(p11), +dup(7)(q11q36), +i(15)(q10),inc/46,XX. The findings indicate some cytogenetic similarities between benign/borderline malignant phyllodes tumors and fibroadenomas of the breast, presumably reflecting similar pathogenetic mechanisms in the two types of mixed-lineage tumors.     

Mapping of chromosome 3p deletions in human epithelial ovarian tumors

Epithelial ovarian tumors frequently display deletions on the short arm of chromosome 3 suggesting the existence of tumor suppressor genes within the deleted regions. We have recently established a primary tissue culture system as a model to investigate the genetic events associated with ovarian cancer. The frequencies of loss of heterozygosity (LOH) at 16 loci representative of chromosome 3p in 33 tumor biopsies and 47 ovarian primary cultures derived from unselected ovarian cancers were examined. This repertoire also included benign and borderline tumors as well as malignant ovarian ascites. LOH was observed in 25 (31%) samples for at least one marker: 21 of 58 malignant, two of 12 borderline and two of 10 benign specimens. Chromosome 3p loss was not restricted to ovarian tumors of high grade and stage. LOH was observed in both cultured and non cultured tumors and ascites. A spontaneously immortalized cell line derived from a malignant ovarian ascites, OV-90, displayed LOH of the majority of markers suggesting loss of one homolog of chromosome 3p. The pattern of deletion displayed by these 25 samples enabled the determination of at least two distinct regions of overlapping deletions on chromosome 3p extending from D3S1270 to D3S1597 and from D3S1293 to D3S1283. In addition, a region proximal to D3S1300 was deleted in a subset of samples. Although loss of loci overlapping these three regions (Regions I, II and III) were observed in malignant and benign tumors, in borderline tumors loss was observed of markers representative of Region III only. While RARbeta is presently included in Region II, the minimal regions of deletion exclude VHL, TGFBR2, PTPase(gamma) and FHIT as candidate tumor suppressors in ovarian tumorigenesis.     

Assembly of DNA with histones and nonhistone chromosomal proteins in vitro

We have examined, by protein binding assays, thermal denaturation, and circular dichroism, the possible effects of histones on nonhistone chromosomal protein (NHCP) interactions with DNA. For these studies, we have fractionated mouse Krebs II chromosomal proteins into three discrete fractions: Mo, 5 M urea-soluble NHCP; M1, 5 M urea-1 M NaCl-soluble NHCP from 5 M urea-extracted chromatin; and M3, 5 M urea-3 M NaCl-soluble chromosomal proteins from 5 M urea-1 M NaCl-extracted chromatin. These fractions contain heterogeneous populations of NHCP, and were found to differentially affect histone binding to DNA by methods of reconstitution, or by direct binding of M0, M1, or M3 to urea-salt reconstituted DNA with histones. M0 was found to exert a unique effect on the thermal denaturation and circular dichroic spectra of DNA-histone complexes. M0 from Krebs II chromatin was also found to complete for DNA sites in the presence of M0 from mouse liver chromatin. In addition, in 5 M urea, pH 8.0, histone binding to DNA reached saturation at 1.85 mg/mg of DNA, higher than the in vivo ratio of 1.00 mg/mg of DNA. Saturation of histone binding to DNA occurred only in the presence of 5 M urea, resulting in a reduction of nonspecific histone-histone interactions on DNA.