Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Multicolor”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed2003

A recurrent chromosome translocation breakpoint in breast and pancreatic cancer cell lines targets the neuregulin/NRG1 gene.

The 8p11-21 region is a frequent target of alterations in breast cancer and other carcinomas. We surveyed 34 breast tumor cell lines and 9 pancreatic cancer cell lines for alterations of this region by use of multicolor fluorescence in situ hybridization (M-FISH) and BAC-specific FISH. We describe a recurrent chromosome translocation breakpoint that targets the NRG1 gene on 8p12. NRG1 encodes growth factors of the neuregulin/heregulin-1 family that are ligands for tyrosine kinase receptors of the ERBB family. Breakpoints within the NRG1 gene were found in four of the breast tumor cell lines: ZR-75-1, in a dic(8;11); HCC1937, in a t(8;10)(p12;p12.1); SUM-52, in an hsr(8)(p12); UACC-812, in a t(3;8); and in two of the pancreatic cancer cell lines: PaTu I, in a der(8)t(4;8); and SUIT-2, in a del(8)(p). Mapping by two-color FISH showed that the breaks were scattered over 1.1 Mb within the NRG1 gene. It is already known that the MDA-MB-175 breast tumor cell line has a dic(8;11), with a breakpoint in NRG1 that fuses NRG1 to the DOC4 gene on 11q13. Thus, we have found a total of seven breakpoints, in two types of cancer cell lines, that target the NRG1 gene. This suggests that the NRG1 locus is a recurring target of translocations in carcinomas. PCR analysis of reverse-transcribed cell line RNAs revealed an extensive complexity of the NRG1 transcripts but failed to detect a consistent pattern of mRNA isoforms in the cell lines with NRG1 breakpoint.

Breast Neoplasms↗
PubMed2003

More extensive genetic alterations in unmutated than in hypermutated cases of chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (CLL) is not a uniform disease entity; approximately half of the CLL cases have undergone immunoglobulin V(H) gene hypermutation, whereas the other half display unmutated V(H) genes. We investigated genome changes in 12 hypermutated cases (M-CLL) and 22 unmutated cases (UM-CLL) by use of comparative genomic hybridization, G-banding, and multicolor fluorescence in situ hybridization (m-FISH) after optimal mitogen stimulation and FISH analysis of typical CLL aberrations: 11q deletion, 13q deletion, and trisomy 12. Very high frequencies of aberrations were found in both groups: 82% in UM-CLL and 83% in M-CLL. Deletions of 11q and 13q were equally distributed in M-CLL and UM-CLL. However, larger aberrations detectable by CGH, trisomy 12, and complex aberrations were less frequent in M-CLL than in UM-CLL. These observations led to a hypothesis that unmutated and mutated CLL have different biological Backgrounds, given that large and/or complex chromosomal aberrations and hypermutation of the CLL progenitor cells tend to be mutually exclusive.

Chromosome Aberrations↗
PubMed2003

Cytogenetic characterization of tumors of the vulva and vagina.

Neoplasms of the vulva and vagina account for less than 5% of all female genital tract cancers. Squamous cell carcinoma (SCC) represents more than 70% of the cases in both locales, followed by melanoma, basal cell carcinoma, Paget's disease, and other carcinoma subtypes. Until recently, only few cases had been analyzed by chromosome banding techniques and karyotyped, and also the number subjected to molecular cytogenetic analysis remains low. To understand better the genetic changes harbored by the neoplastic cells in cancer of the vulva and vagina, we analyzed cytogenetically 51 such tumors, finding karyotypic abnormalities in 37. All tumors were analyzed by G-banding, sometimes supplemented by multicolor fluorescence in situ hybridization, and a subset of tumors was also analyzed by comparative genomic hybridization. The two cytogenetically abnormal cases of Paget's disease both had two clones, one with gain of chromosome 7 as the sole change, the other with loss of the X chromosome among, in one case, other aberrations. The four cytogenetically abnormal malignant melanomas (three of the vulva, one of the vagina) presented complex karyotypes with aberrations involving different chromosomes but most often chromosome 1, specifically 1p12-q41. In the 31 cytogenetically abnormal SCCs, different clonal karyotypic abnormalities were seen. Intratumor heterogeneity with multiple clones was observed in 11 cases. The clones were cytogenetically unrelated in eight tumors but related in three, indicating that in the latter clonal evolution had taken place from a single malignantly transformed cell. The main chromosomal imbalances were gains of, or from, chromosome arms 3q, 5p, 8q, 9q, and 19q, and loss from 11q. Breakpoint clusters were seen in 11q13-23, 2q22-35, and 19q13, as well as in the centromeres and pericentromeric bands of chromosomes 3, 8, 9, 13, 14, and 22.

Carcinoma in Situ↗
PubMed2003

ALK-ATIC fusion in urinary bladder inflammatory myofibroblastic tumor.

In this report, we describe an inflammatory myofibroblastic tumor (IMT) of the urinary bladder in a 46-year-old man. Tumor cells presented striking cytoplasmatic ALK immunopositivity. Cytogenetic and FISH analysis, by use of a multicolor chromosome 2 banding probe, revealed a 46,XY,der(2)(2pter-->2p23:2q35-->2q37:2p11-->2q35:2p23-->2p11:2q37-->2qter) karyotype. Subsequent FISH and RT-PCR analysis confirmed the ALK-ATIC chimeric fusion in tumor cells. This is the first evidence of a variant rearrangement involving the ATIC gene in IMT and the first cytogenetic description of an IMT originating from the urinary bladder.

Anaplastic Lymphoma Kinase↗
PubMed2003

Premature chromosome condensation revisited: a novel chemical approach permits efficient cytogenetic analysis of cancers.

Chemical induction of premature chromosome condensation (PCC) was investigated and optimized to be able to analyze the chromosomal constitution of cancer cells independent of mitosis and with minimal culture artifacts. A potent protein phosphatase inhibitor, calyculin A, was used to induce PCC in normal diploid cells, in several established human tumor cell lines, and in cells isolated from freshly dissected adenomatous polyps of a patient with hereditary colorectal cancer. In parallel, mitotic arrest was pursued by use of Colcemid. In cell lines, a difference of up to 10-fold was found between frequency of cells with PCC induced by calyculin A (PCC index) and the mitotic index after treatment with Colcemid. In the fresh tumor specimens, Colcemid failed to result in metaphase formation, whereas a regimen of 80 nM calyculin A for 75 min, after only 2 days of culturing, resulted in a PCC index of 2-5%. pq-COBRA-FISH (COmbined Binary RAtio labeling-fluorescence in situ hybridization) was used for a detailed analysis of four cell lines treated with calyculin A, which proved that PCC spreads are amenable to molecular karyotyping, and a comparison between PCC spreads and metaphases from mitotic arrest revealed no discrepancies in karyotypes. pq-COBRA-FISH on PCC spreads from fresh colon tumor samples revealed only numerical and no structural abnormalities. Calyculin A-induced PCC combined with multicolor FISH gives a new opportunity for analysis of the chromosomal constitution of G(1) and G(2) cancer cells and may find application in the study of the role of chromosome instability in cancer development.

Adenomatous Polyposis Coli↗
PubMed2001

Genome-wide analysis of sixteen chordomas by comparative genomic hybridization and cytogenetics of the first human chordoma cell line, U-CH1.

Cytogenetic information on chordomas is rudimentary and restricted to GTG-banding analysis of 26 cases worldwide. In this study, we present the chromosomal imbalances detected in a series of 16 chordomas (10 sacrococcyeal, five sphenooccipital, and one spinal) from 13 patients using comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). On average, 3.2 losses and 4.2 gains were detected per tumor. The most common DNA copy number alterations were losses on chromosomal arms 3p (50%) and 1p (44%). Losses of 3p were detected in five of seven primary chordomas. Therefore, the loss of 3p might be an early event in chordoma genesis. The most common gains involved 7q (69%), 20 (50%), 5q (38%), and 12q (38%). Additionally, we raised the first human chordoma cell line, U-CH1, from a recurrence of a sacral chordoma. U-CH1 and its parent tumor had almost the same CGH profile. According to GTG-banding and multicolor FISH, U-CH1 has the following clonal chromosomal abnormalities: der(1)t(1;22), del(4), +del(5), +del(6), +7, del(9), del(10), +der(20)t(10;20), +21. Thus, the novel permanent human chordoma cell line U-CH1 has chordoma-typical cytogenetic aberrations. Our data suggest that tumor suppressor genes or mismatch repair genes (located at 1p31 and 3p14) and oncogenes (located in 7q36) might be involved in chordoma genesis.

Adult↗
PubMed2002

Differentially amplified chromosome 12 sequences in low- and high-grade osteosarcoma.

Most osteosarcomas are highly aggressive malignancies characterized by a complex pattern of chromosome abnormalities. However, a subgroup of low-grade, parosteal tumors exhibits a relatively simple aberration pattern dominated by ring chromosomes carrying amplified material from chromosome 12. To assess whether sequences from this chromosome were differentially amplified in low- and high-grade osteosarcomas, copy numbers of the CCND2, ETV6, KRAS2, and D12S85 regions in 12p and the MDM2 region in 12q were evaluated by interphase or metaphase fluorescence in situ hybridization (FISH) in 24 osteosarcomas. Amplification of MDM2 was detected in all five low-grade and four high-grade osteosarcomas, all of which showed ring chromosomes. An overrepresentation of 12p sequences was found in 1/5 low-grade and in 9/19 high-grade tumors. Multicolor single-copy FISH analysis of metaphase cells from six high-grade tumors showed that extra 12p material either occurred together with MDM2 in ring chromosomes or was scattered over the genome as a result of complex structural rearrangements. Most tumors (8/10) not containing amplification of the assessed chromosome 12 loci exhibited a nondiploid pattern at evaluation with probes for centromeric alpha satellite sequences. These findings indicate that gain of sequences from the short arm of chromosome 12 could be a possible genetic pathway in the development of aggressive osteosarcoma.

Adolescent↗
PubMed2004

Cryptic insertion producing two NUP98/NSD1 chimeric transcripts in adult refractory anemia with an excess of blasts.

We performed cytogenetic and molecular studies on an adult patient with refractory anemia with an excess of blasts with an add(11)(p15). Multicolor fluorescence in situ hybridization (FISH) identified the extra material on 11p as belonging to chromosome 15. Metaphase FISH with probes for chromosomes 5, 11, and 15 revealed a complex four-break rearrangement. Clone RP5-1173K1, containing exons 10-20 of the NUP98 gene, gave three fluorescence signals on the normal 11, the der(5), and the der(15). 3'-RACE-PCR identified an in-frame fusion between NUP98 and NSD1, which was confirmed by RT-PCR. Two different spliced forms, that is, NUP98 exon 11/NSD1 exon 6 and NUP98 exon 12/NSD1 exon 6, were detected. The reciprocal NSD1/NUP98 was not found. A dual-color experiment with RP5-1173K1 and CTC-549A4, spanning the entire NSD1 gene, indicated an insertion of NUP98 into the NSD1 locus. This is the first report of an adult with myelodysplastic syndrome (MDS) harboring an NUP98/NSD1 fusion resulting from insertion of 5'-NUP98 into the NSD1/5q35 locus.

Amino Acid Sequence↗
PubMed2005

Cytogenetic manifestations of multiple myeloma heterogeneity.

To investigate the genetic basis of the great heterogeneity observed in the clinical behavior of multiple myeloma (MM), a combined approach of G-banding, interphase fluorescence in situ hybridization (FISH), and multicolor FISH (M-FISH) was employed to analyze 70 samples from 53 patients with MM. G-banding revealed abnormal karyotypes in 77% of the cases. The origin of 31 chromosome markers was identified or revised by M-FISH. Combined metaphase karyotypic data and interphase FISH findings, using the immunoglobulin heavy-chain (IGH), IGH/cyclin D1 gene (CCND1), and D13S319 probes, revealed chromosome abnormalities in all evaluated patients and marked inter- and intratumor cytogenetic heterogeneity in the investigated MM samples. Cytogenetically unrelated clones were detected in 26% of the cases, mostly MM evaluated at diagnosis, whereas cytogenetic clonal evolution, manifested as related clones in 20% of the cases, was associated with disease progression. Among the 14q32 rearrangements, present in 66% of the cases, at least three cytogenetic subsets could be identified: one with t(11;14), usually without 13q14 deletion; another with other IGH changes, often 13q14 deletion, and hypodiploid modal chromosome number; and a third without changes in 14q32 but with abnormalities of chromosome 17. The correlation found between cytogenetic and clinicopathologic characteristics provided support for the concept that general genomic features in conjunction with specific chromosome rearrangements define the malignant phenotype in the various subsets of MM.

Adult↗
PubMed2005

Centromeric breakage and highly rearranged chromosome derivatives associated with mutations of TP53 are common in therapy-related MDS and AML after therapy with alkylating agents: an M-FISH study.

Multicolor fluorescence in situ hybridization (M-FISH) was performed on bone marrow cells of 116 unselected cases of therapy-related myelodysplasia (t-MDS) or acute myeloid leukemia (t-AML), and the results were compared with those of previously performed with G-banding. Among 18 patients with a normal karyotype, no cryptic chromosome aberrations were observed with M-FISH. In 56 patients with a previously solved abnormal karyotype, only 17 new aberrations were identified, whereas 153 new aberrations were detected by M-FISH in 42 patients with a previously unsolved karyotype. In total, 112 of the new aberrations were unbalanced translocations, and only nine were balanced translocations. A clustering of breakpoints was observed in the centromeric or pericentromeric region of chromosomes 1, 5, 7, 13, 17, 21, and 22 in 48 of 98 patients with t-MDS and t-AML and an abnormal karyotype, and was related to previous therapy with alkylating agents. In seven of eight patients with chromosome derivatives containing material from three or more chromosomes or having sandwichlike chromosomes, those made up of several small interchanging layers of material from two chromosomes showed mutations of TP53. M-FISH had little impact on the prognostic classification of t-MDS and t-AML, as only three patients changed prognostic groups as a result of M-FISH.

Acute Disease↗
PubMed2005

An integrated mBAND and submegabase resolution tiling set (SMRT) CGH array analysis of focal amplification, microdeletions, and ladder structures consistent with breakage-fusion-bridge cycle events in osteosarcoma.

Osteosarcoma (OS) is characterized by chromosomal instability and high-copy-number gene amplification. The breakage-fusion-bridge (BFB) cycle is a well-established mechanism of genomic instability in tumors and in vitro models used to study the origins of complex chromosomal rearrangements and cancer genome amplification. However, until now, there have been no high-resolution cytogenetic or genomic array studies of BFB events in OS. In the present study, multicolor banding (mBAND) FISH and submegabase resolution tiling set (SMRT) array comparative genomic hybridization (CGH) were used to identify and map genomic signatures of BFB events in four OS cell lines and one patient tumor. The expected intermediates associated with BFB-dicentric chromosomes, inverted duplications, and intra- and interchromosomal amplifications-were identified. mBAND analysis provided detailed mapping of rearrangements in 1p, 6p, and 8q and showed that translocation junctions were often in close proximity to fragile sites. More detailed mBAND studies of OS cell line MG-63 revealed ladderlike FISH signals of equally spaced interchromosomal coamplifications of 6p21, 8q24, and 9p21-p22 in a homogeneously staining region (hsr). Focal amplifications that concordantly mapped to the hsr were localized to discrete genomic intervals by SMRT array CGH. The complex amplicon structure in this hsr suggests focal amplifications immediately adjacent to microdeletions. Moreover, the genomic regions in which there was deletion/amplification had a preponderance of fragile sites. In summary, this study has provided further support for the role of the BFB mechanism and fragile sites in facilitating gene amplification and chromosomal rearrangement in OS.

Cell Line, Tumor↗
PubMed2006

Amplified, lost, and fused genes in 11q23-25 amplicon in acute myeloid leukemia, an array-CGH study.

Gene amplifications occur rarely in hematologic neoplasms. We characterized two cases of acute myeloid leukemia (AML) with marker chromosomes and 11q23-25 amplicons. Case 1 was a 14-year-old male with an additional ring of chromosome 11 material as the sole karyotypic abnormality, as determined by G-banding and multicolor fluorescence in situ hybridization. Standard comparative genomic hybridization (CGH) showed amplification in 11q23-qter. However, the MLL gene, in 11q23, was not amplified by FISH. Case 2 was a 38-year-old male with the G-banding karyotype 51,XY,+8,+19,+3mar and with 11q22-qter amplification by standard CGH. This patient also had the MLL-LARG fusion gene. We used microarray-based CGH (array-CGH) to characterize the amplicons. In case 1, the amplified region in 11q24.3-25 (5.5 Mb) was continuous, and MLL was not amplified, as expected. In case 2, the amplicon was divided into two distinct parts, in 11q23.3 (1.2 Mb) and in 11q23.3-25 (13.3 Mb). It contained a loss ( approximately 1 Mb) in 11q23.3, and the amplicon breakpoint was in the middle of MLL. Although the amplicon size varied, the patients had a common amplified region in 11q24-25 that comprised 14 genes. Expression microarray of case 1 revealed that three of these genes, FLI1, NFRKB, and SNX19, were also overexpressed. The results indicate that the 11q24-q25 region may harbor new candidate oncogenes. In addition, the complex amplicon of case 2 suggests some intriguing chromosomal mechanisms.

Acute Disease↗
PubMed2007

Relationships between regulatory T cells and CD8+ effector populations in patients with squamous cell carcinoma of the head and neck.

BACKGROUND: Homeostasis of circulating T cells is regulated in complex ways that have not yet been well defined. The balance between type 1 and type 2 T-cell subsets in cancer patients is thought to modulate antitumor immunity. Meanwhile, CD4+CD25+ regulatory T cells (Treg), which are potent inhibitors of antitumor immune responses, also play an invaluable role in maintaining immune homeostasis. METHODS: Peripheral blood was obtained from 42 patients with squamous cell carcinoma of the head and neck (SCCHN) and 24 healthy age-selected donors. The percentages of T-cell subsets and their cytokine profiles expressed in response to ex vivo stimulation were studied by multicolor flow cytometry. RESULTS: Although patients with SCCHN had a lower percentage (p < .05) of circulating CD4+ T cells than healthy donors, CD4+CD25+ regulatory T cells (Treg) were increased in the patients (p < .01). A significant increase in Th1 and Th2 CD4+ T cells was observed in the patients after ex vivo stimulation with phorbol 12-myristate 13-acetate /ionomycin. The percent of Treg inversely correlated with that of total CD8+ T cells (p < .05), CD8+IFN-gamma+ (Tc1) cells (p < .05), and CD8+IL-4+ (Tc2) cells (p < .01). There was a highly significant correlation between Tc1 and Tc2 CD8+ T cells (p < .0001) in SCCHN patients but not in controls. CONCLUSIONS: Treg are increased in proportion in the circulation of patients with SCCHN. These cells appear to downregulate cytokine expression in both Tc1 and Tc2 subsets of CD8+ effector T cells, which may be responsible for antitumor responses.

Adult↗
PubMed2005

Subtelomeric rearrangements in the mentally retarded: a comparison of detection methods.

In recent years, subtelomeric rearrangements, e.g., chromosome deletions or duplications too small to be detected by conventional cytogenetic analysis, have emerged as a significant cause of both idiopathic and familial mental retardation. As mental retardation is a common disorder, many patients need to be tested on a routine basis. In this review, we will discuss the different methods that have been applied in laboratories worldwide, including multiprobe fluorescence in situ hybridization (FISH), multiallelic marker analysis, multiplex amplifiable probe hybridization (MAPH), multiplex ligation-dependent probe amplification (MLPA), quantitative real-time PCR, comparative genomic hybridization (CGH), and multicolor FISH, including spectral karyotyping (SKY), subtelomeric combined binary ratio labeling FISH (S-COBRA FISH), multiplex FISH telomere integrity assay (M-TEL), telomeric multiplex FISH (TM-FISH), and primed in situ labeling (PRINS).

Alleles↗
PubMed2002

Identification of known and novel immunogenic T-cell epitopes from tumor antigens recognized by peripheral blood T cells from patients responding to IL-2-based treatment.

In previous studies CD8+ T cells specific for melanocyte antigens have been frequently found in melanoma patients responding to interleukin-2 (IL-2)-based therapies. In our study we analyzed the suitability of using circulating T cells from melanoma patients with clinical response after IL-2-based therapy to identify novel T-cell epitopes from defined tumor antigens. Using unstimulated peripheral blood mononuclear cells and the interferon-gamma (IFN-gamma) ELISPOT assay, we studied CD8(+) T-cell responses against 5 peptides from the tumor antigen tyrosinase (Tyr) selected by epitope prediction using an HLA-A1-binding computer algorithm. T cells specifically secreting IFN-gamma in response to 3 of these 5 peptides, namely, Tyr (454-463), Tyr (146-156) and Tyr (243-251), could be detected in 4 of 4 HLA-A1-positive patients with clinical response. In contrast, no T-cell responses against these peptides were seen in 6 HLA-A1-positive melanoma patients with progressive disease and in 8 healthy subjects. We could generate specific cytotoxic T lymphocytes (CTL) against Tyr (454-463) using peptide-pulsed autologous dendritic cells as antigen-presenting cells. The induced CTLs efficiently killed melanoma cells that express HLA-A1 and tyrosinase. The peptides Tyr (146-156) and Tyr (243-251) had recently been identified as CTL epitopes by other groups. Further ex vivo characterization of the T cells reactive against the novel epitope Tyr (454-463) in 1 patient by multicolor flow cytometry showed specific CD3+/CD8+/IFN-gamma+ T cells with frequencies of up to 0.41% of the CD3+/CD8+ T-cell population. Most of this T-cell population also expressed granzyme B. Our data confirm that in patients with tumor regressions induced by immunotherapy or chemoimmunotherapy circulating T cells reactive with tyrosinase epitopes can frequently be detected. Peripheral blood T cells from such patients are a valuable source for screening peptides selected by epitope prediction This strategy facilitates the rapid identification of immunogenic T-cell epitopes that are probable targets of immune-mediated tumor rejection.

Antigens, Neoplasm↗
PubMed2006

T cells specific for HPV16 E7 epitopes in patients with squamous cell carcinoma of the oropharynx.

Squamous cell carcinomas of the oropharynx (SCCO) are often infected with oncogenic human papilloma virus (HPV) subtype 16. To determine the frequency of T cells specific for human leukocyte antigen (HLA)-A2.1 restricted HPV16 E7 protein-derived epitopes, tetramer analysis was performed using peripheral blood lymphocytes of 20 HLA-A2.1+ patients and 20 HLA-A2.1+ healthy individuals. Tetramers specific for 3 HPV16 peptides (E711-20, E782-90 and E786-93), an influenza matrix peptide (a model recall antigen) or an HIV reverse transcriptase peptide (a model novel antigen) were used in multicolor flow analysis. The HPV-specific T-cell frequencies were correlated with the HPV16 E7 and p16 status in tumor sections. In vitro stimulation (IVS) with autologous dendritic cells (DC) pulsed with HPV16 E7 epitopes was performed to demonstrate proliferation and antitumor activity of the HPV-responsive T cells. Frequencies of CD8+ T cells specific for HPV16 E7 peptides were not significantly different in patients with SCCO relative to normal donors. However, patients with tumors expressing HPV16 E7 (60%) and p16 (50%) had an increased frequency (p<0.05) of T cells specific for the E711-20 epitope compared to those with tumors negative for both markers. HPV16 E711-20 and HPV16 E786-93 specific T cells were expandable upon IVS with cognate peptide-pulsed DC and were reactive against peptide-pulsed targets or, in case of the E711-20 epitope-specific T cells, against HPV16 E7 expressing CaSki cell line. Thus, in patients with HPV16+ SCCO, precursor T cells specific for E711-20 epitope are present (1/3,947) in the circulation, are responsive to stimulation with the cognate viral peptide and recognize in vitro HPV16 E7+ tumor cells. Further studies have to elucidate why those T cells are unable to eliminate the tumor in vivo and this might also allow for finding potential strategies that will increase the chances of developing a future HPV-based vaccine in patients with SCCO.

Antigens, Viral↗
PubMed2007

Identification of the human/mouse syntenic common fragile site FRA7K/Fra12C1--relation of FRA7K and other human common fragile sites on chromosome 7 to evolutionary breakpoints.

Common fragile sites (CFSs) are expressed as chromosome gaps in cells of different species including human and mouse as a result of the inhibition of DNA replication. They may serve as hot spots for DNA breakage in processes such as tumorigenesis and chromosome evolution. Using multicolor fluorescence in situ hybridization mapping, the authors describe here human CFS FRA7K on chromosome band 7q31.1 and its murine homolog Fra12C1. Within the syntenic FRA7K/Fra12C1 region lies the IMMP2L/Immp2l gene with a size of 899/983 kb. The authors further mapped 2 amplification breakpoints of the breast cancer cell line SKBR3 to the CFSs FRA7G and FRA7H. The 5 molecularly defined CFSs on chromosome 7 do not preferentially colocalize with synteny breaks between the human and mouse genomes and with intragenomic duplications that have occurred during chromosome evolution. In addition, in contrast to all currently reported data, CFSs in chromosome band 7q31 do not show increased DNA helix flexibility in comparison with control regions without CFS expression.

Animals↗
PubMedDate not supplied

Sex chromosome alignment at meiosis of azoospermic men with azoospermia factor microdeletion.

Deletions in the q arm of the Y chromosome result in spermatogenesis impairment. The aim of the present study was to observe the X and Y chromosome alignment in the spermatocytes of men with Y chromosome microdeletion of the azoospermia factor (AZF) region. This was performed by multicolor fluorescence in situ hybridization probes for the centromere and telomere regions. Testicular biopsies were performed in a testicular sperm extraction-intracytoplasmic sperm injection set-up in 11 azoospermic men: 8 (nonobstructive) with AZF deletions and 3 (obstructive) controls. Histological sections, cytology preparations of the testicular biopsies, and evaluation of the meiosis according to the percentage of XY and 18 bivalents formation were assessed. Spermatozoa were identified in at least one location in controls and specimens with AZFc-deleted Y chromosomes. Complete spermatocyte arrest was found in those with a deletion that included the entire AZFb region. Bivalent formation rate of chromosome 18 was high in all samples (81%-99%). In contrast, the rate of bivalent X-Y as determined by centromeric probes was lower but in the range favorable with spermatozoa findings in controls and patients with the AZFc deletion (56%-90%), but not in those with AZFb-c deletions (28%-29%). A dramatic impairment in the normal alignment of X and Y telomeres in the specimen with AZFb-c deletion was shown (29%), compared to the specimens with AZFc deletion (70%-94%). It is suggested that the absence of sperm cells in specimens with the entire AZFb and with AZFb-c deletions is accompanied by meiosis impairment, perhaps as a result of the extent of the deletion or because of the absence of genes that are involved in the X and Y chromosome alignment.

Biopsy↗