Clustering of two fragile sites and seven homeobox genes in human chromosome region 2q31-->q32.1

In this study we have used FISH to examine the relationship between a group of homeobox genes, namely DLX1/DLX2, EVX2 and four HOXD genes (10, 11, 12, 13), that map to region q31 on chromosome 2, and the FRA2G and FRA2H fragile sites located at 2q31 and 2q32.1 respectively. Our results indicate that these homeobox genes lie between the two fragile regions.     

Apoptosis induced by butyrate is independent of Jak/STAT signaling in a fibrosarcoma cell line

The aim of this study was to evaluate the participation of the Jak-1 and STAT-1 proteins in sodium butyrate-induced apoptosis in 2C4 cells derived from human fibrosarcoma. Making use of Jak-1 or STAT-1 deficient cell lines, we demonstrated that the apoptotic process induced by butyrate is independent of the presence of these proteins. In addition, this work showed that, although the constitutive expression of pro-caspases-2 and -3 is reduced in STAT-1 cells, the activity of caspase-3 is preserved in both Jak-1 and STAT-1 deficient cells and is similar to that seen in 2C4 parental cells. In conclusion, we demonstrated that the absence of functionally active Jak-1 or STAT-1 protein directly affects the TNF-alpha-induced apoptosis, but does not alter the sodium butyrate-induced apoptosis in cells derived from human fibrosarcoma.     

Cytogenetic mapping of five YAC clones to human chromosome region 2q31 --> q32.1 in relation to the FRA2G common fragile site

In this work, five YAC clones have been mapped by fluorescent in situ hybridization (FISH) to human chromosome region 2q31 q32.1 and ordered in relation to each other and to the FRA2G common fragile site. YAC clones that span the fragile site have been identified. Moreover a deleted HOXD 13 gene has been identified on the 942D2 YAC.     

Numerical chromosomal aberrations of chromosome 1 and 7 in dysplastic cervical smears

Cervical smears with Papanicolaou's staining (PAP) reveal only morphological characteristics of epithelial cells of the cervix uteri. Since chromosomal aberrations are known to play a role in malignant transition, we analyzed cervical smears for numerical changes of the chromosomes 1 and 7 with fluorescence in-situ hybridization to probe for a diagnostic value of these chromosomes in the characterization of cervical dysplasia. Cervical smears were collected from 21 patients with suspect histology of curettage or biopsy specimen, 14 of them having been subsequently graded as cervical intraepithelial neoplasia (CIN) III and 5 as CIN II. Nineteen normal cervical smears (PAP I-II) served as controls. Smears were hybridized with chromosomal enumeration probes for chromosome 1 and 7. Disomic cells (2 copies of chromosome 1 and 7) were decreased in the CIN II (63%) and CIN III group (57%) with respect to the control group (77%). Cells with 3 signals for chromosome 7 were significantly more frequent in the CIN III and the CIN II group than in the control group (6.7, 6.4 and 0.7%, respectively). Only the CIN II group (10%), but not CIN II (6%), showed a significant trisomy for chromosome 1 as compared with the controls (3.8%). A close correlation between the incidence of trisomy 1 or 7 and PAP grading was observed. PAP III-IIID smears with high trisomy 1 counts corresponded to CIN III histology, while all CIN II patients were PAP III-IIID with low incidence of trisomy 1. We conclude that trisomy of chromosome 7 is a feature of cervical dysplasia and seems to be an early event in dysplastic transition. In contrast, trisomy of chromosome 1 is observed only in high grade dysplasia and may be a marker for pre-malignant lesions.     

Identification of a haplosufficient 3.6-Mb region in human chromosome 11q14.3-->q21

Cytogenetic deletions are almost always associated with phenotypic abnormality and are very rarely transmitted. We have located a hitherto undescribed, familial deletion involving the region 11q14.3-->q21 in five individuals in a three-generation kindred. Four of the deletion carriers show no phenotypic abnormality; the other, who is the proband, was investigated for short stature and poor academic progress. In view of the apparent innocuous nature of this genetic imbalance, the deletion was investigated in detail to determine its size (3.6 Mb) and location with reference to molecular markers and genetic content. The deleted region is described by a contig of 37 BACS including the flanking regions, which we have assembled. Several possible contributory factors are considered, which might explain the lack of clinical significance of this large deletion. It is notable that there are few genes in this region and none have known functions. All most likely have copies elsewhere in the genome and a number of other hypothetical genes appear to be members of certain gene families, i.e. none is unique. Part of the region (1 Mb) is also duplicated at the pericentromeric region 11p11. Given the very low proportion of the genome occupied by single copy genes and their uneven distribution, regions such as this, which appear to be functionally haplosufficient, may be more common than hitherto recognised.     

The assignment of PRKCI to bovine chromosome 1q34-->q36 by FISH suggests a new assignment to human chromosome 3

In metaphases from female mouse fibroblasts, successive stainings by Giemsa and DAPI and immunolabeling of 5-methylcytosine were performed with or without bromodeoxyuridine pretreatment. It was shown that, compared to all other chromosomes, the late replicating X is the least methylated, the most compacted, and the most intensely stained by DAPI and Giemsa.