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Chromosomal abnormalities, p53 and Bcl-2 expression and clinical outcome in choroidal melanoma.

OBJECTIVE: To determine whether alterations of p53, Bcl-2 and chromosomes were present in choroidal melanoma and to further characterize the prognosis of these changes. METHODS: The expression of p53 and Bcl-2 protein was assessed by immunohistochemistry from paraffin blocks. Tumours were analysed by comparative genomic hybridization (CGH) to identify chromosomal aberrations. Fifteen tumours were studied, and the survival results were compared by Spearman correlation analysis with a mean follow-up of 36.5+/-8 months. The majority of tumours were mixed (eight cases), and the others were spindle cell (four cases) and epithelioid cell (three cases) types. Four patients have already died due to metastatic disease. RESULTS: p53 was expressed at a low percentage in only two tumours. There were no differences in Bcl-2 expression in our cases. Bcl-2 was expressed by the majority of cells in all cases. Chromosomal copy number aberrations were detected in 10 of the 15 patients by CGH analyses. A gain at chromosome 8 and a loss at chromosome 3 were the most frequently seen abnormalities. The other aberrations observed were losses at 6q, 7q14 and 17p13-15, and gains at 6p and 18q. Two of the three cases with a loss at 17p13 showed a low percentage expression of p53. No relationship was determined between the chromosomal abnormalities, cell type, expression of p53 and survey. The presence of a chromosome 6q deletion in two of the four patients who died of metastatic disease may indicate that chromosome 6q deletion may be correlated with a poor prognosis. CONCLUSIONS: Our results suggest that choroidal melanomas show high levels of chromosomal alterations. Further studies are necessary to determine the correlation between chromosomal abnormalities and prognosis.

Adult↗

Two myelodysplastic syndrome cases with the inv(11)(p15q23) as a sole chromosomal abnormality.

Two myelodysplastic syndrome cases (one with acute nonlymphocytic leukaemia (M2) transformed from myelodysplastic syndrome (MDS), and the other with chronic myelomonocytic leukaemia following refractory anaemia with excess of blasts in transformation) showed the inv(11)(p15q23) as a sole chromosomal abnormality. Gene probes for c-Ha-ras-1 and c-ets-1 were hybridized to metaphase cells from bone marrow of these patients. c-ets-1 gene, which is mapped to 11q23, was demonstrated to have translocated to the short arm in the rearranged chromosome 11 in both cases. On the other hand, c-Ha-ras-1 gene, which is located at 11p15, was translocated to the long arm in the rearranged chromosome 11 in patient 1, and deleted in patient 2. Our findings suggest that there may be heterogeneity in molecular events involved in the chromosomal rearrangement among the inv(11)-carrying MDS.

Adolescent↗

The importance of surgical evaluation of patients with "Turner-like" sex chromosomal abnormalities.

Children with "pure" gonadal dysgenesis do not require abdominal explorations to remove their gonads, because the risk of development of malignancy is minimal. Children with "mixed" gonadal dysgenesis, who usually present with sexual ambiguity, need to have gonadectomy because of the high incidence of malignancy in these gonads. We present four children (three adolescents and one two year old) who presented with minimal somatic anomalies, who did not have sexual ambiguity. The prominent features were primary amenorrhea and short stature in the adolescents, and minor dysmorphic features in the small child. On the basis of these physical features, complete genetic evaluation was carried out, and a Y chromosome or an unidentifiable fragment was identified in all four cases. At exploration, bilateral genital streaks were found, and were removed. In addition to the usual microscopic features of the streaks, Leydig cells and tubular structures resembling rete testis were seen in all the gonads. In one gonad, a gonadoblastoma was found. Since this type of gonad is "at risk" for the development of gonadoblastoma, the need for complete genetic evaluation of all females with "Turner-like" chromosomal abnormalities, although phenotypically female, is emphasized. If a Y chromosome or any unusual fragment is identified, exploration should be carried out, and any gonad that is not a normal ovary should be removed.

Adolescent↗

Nodulocystic acne, chromosomal abnormality, and diabetes mellitus.

Nodulocystic acne (NCA), a severe dermatologic facial condition, has previously been described in association with the XYY genotype. Presented herein is a severely retarded insulin-dependent diabetic with grade three hypospadias, fibrous testes, and severe NCA. Chromosomal analysis revealed his karyotype to be 46 XY+, (4 p+, 14q-). This case report demonstrates that NCA may occur with chromosomal abnormalities other than a 46 XYY genotype. The need to have karyotypic proof of a phenotypic diagnosis is emphasized.

Acne Vulgaris↗

Transcriptional activation by TAL1 and FUS-CHOP proteins expressed in acute malignancies as a result of chromosomal abnormalities.

Proteins that appear to participate in transcriptional control of gene expression are increasingly implicated in leukemias and malignant solid tumors. We report here that the N-terminal domains of the proteins TAL1 (ectopically activated in T-cell acute leukemias after chromosomal abnormalities caused by V-D-J recombinase error) (V, variable; D, diversity; J, joining) and FUS-CHOP (a liposarcoma tumor-specific fusion protein that is produced as a result of a chromosomal translocation) can function as transcription activators of specific responsive reporter genes. The result with TAL1 provides evidence that transcriptional activation can be mediated by a gene activated by translocation in T-cell acute leukemias. In the case of the liposarcoma, transactivation by the FUS-CHOP protein occurs because the FUS transcriptional activation domain is added to the DNA-binding CHOP protein normally lacking such activity. Therefore, the association of transcriptional activation and DNA-binding elements is a common consequence in proteins activated or newly created as fusion proteins after chromosomal translocations in acute leukemias and in malignant solid tumors.

3T3 Cells↗

Isochromosome 7q and trisomy 8 are consistent primary, non-random chromosomal abnormalities associated with hepatosplenic T gamma/delta lymphoma.

Four patients with hepatosplenic T gamma/delta lymphoma, a rare but distinct entity of peripheral T cell lymphoma, are reported on. In each case, cytogenetic studies showed the presence of an Isochromosome 7q and a trisomy 8. A few chromosome studies have previously been reported in this lymphoma subtype but comparison with these published cases confirms that isochromosome 7q and trisomy 8 are primary, non-random chromosomal abnormalities in hepatosplenic T gamma/delta lymphoma.

Adolescent↗

Unique balanced chromosome abnormalities in treatment-related myelodysplastic syndromes and acute myeloid leukemia: report from an international workshop.

A total of 123 balanced rearrangements, including 26 occurring as a sole anomaly, not known to be recurrent in myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) prior to the Workshop, were ascertained retrospectively from 104 patients with treatment-related MDS/AML (t-MDS/t-AML). Thirteen of the aberrations were reported previously in single cases and hence may be classified as recurrent as a result of the Workshop. Patients with Unique aberrations had complex karyotypes more often (P < 0.001 for all pairwise comparisons) than did other Workshop subgroups, with 72% having 3 or more aberrations. Among 85 cases with secondary chromosomal abnormalities, -5, -7, del(5q), and del(7q) were observed in 76%, which is significantly higher (P < or = 0.007 for all pairwise comparisons) than the frequencies found in the Workshop subgroups of patients with previously known recurring aberrations. The chromosome bands most often involved in balanced aberrations were 1p36 and 3q26-27. Treatment exposure was significantly different (less topoisomerase II inhibitor exposure, more radiotherapy-only exposure) than for patients with 11q23 (P < 0.001 and P = 0.002, respectively) and 21q22 (P = 0.007 and P = 0.002, respectively) abnormalities. The median time from the first toxic exposure to secondary disease, 59 months, was significantly longer (P < or = 0.016 for all significant pairwise comparisons) than the median latency of all other patients except those in the Rare subgroup, and the median survival time, 7 months, was significantly shorter than for patients in the 21q22, inv(16), and t(15;17) subgroups (P < or = 0.002 for all pairwise comparisons), but similar to patients in the 11q23 and Rare subgroups. In contrast to known recurring abnormalities, significantly more patients (61%, all P < 0.001) presented with t-MDS, with over one-third of these patients progressing to t-AML. Thus, this group of patients appears to be more similar to the typical t-MDS/t-AML patients, with complex karyotypes as well as chromosome 5 and 7 abnormalities, than to those with recurrent balanced rearrangements.

Adolescent↗

Abnormal chromosome 16 in clonogenic eosinophils from a case of acute myeloid leukemia (FAB,M2).

A case of acute myeloid leukemia (AML, FAB M2) is described in which the leukemic karyotype showed several numerical and structural cytogenetic abnormalities including an abnormal chromosome 16 with breakpoint at band q22, monosomy for chromosomes 5 and 7, and a single pair of double minute chromosomes. There was no patient history of treatment for a previous malignancy or occupational exposure to mutagens. Bone marrow eosinophilia was seen at presentation for refractory anemia with excess blasts in transformation and when AML was diagnosed. When bone marrow buffy coat cells were cultured in soft agar in the presence of colony stimulating factor, 19% of the colonies and 20% of the clusters were of eosinophils. Cytogenetic examination of pooled eosinophil colonies showed the marker chromosomes that identified the leukemic population.

Bone Marrow↗

Chromosomal abnormalities and sister-chromatid exchange in bone marrow cells of mice and Chinese hamsters after inhalation and intraperitoneal administration: I. Diepoxybutane.

Diepoxybutane (DEB), a direct-acting animal carcinogen, was found to increase the frequency of structural chromosomal abnormalities (CA) and sister-chromatid exchange (SCE) in bone marrow cells of mice and Chinese hamsters, when inhaled from an aerosol during a 2-h head-only exposure or administered as a single intraperitoneal injection. For the purpose of comparing the genotoxicity in the 2 species, both after inhalation and intraperitoneal administration, the systemic DEB dose obtained by inhalation was determined on the basis of blood concentrations and inhalation duration after the investigation of the blood kinetics. The bone marrow cells of male and female NMRI mice were found to be more sensitive than those of Chinese hamsters to the genotoxic activity of DEB.

Administration, Inhalation↗

Specific chromosomal abnormalities characterize four established cell lines derived from malignant human gliomas.

The four permanent human glioma-derived cell lines reported here are the first such lines for which the karyotypes have been followed from the original biopsies through the establishment of the lines in culture. Although ploidy changes were seen, each line retained either distinctive marker chromosomes or the overall original chromosomal distribution allowing the origin of each line to be established with certainty. D-263 MG expresses glial fibrillary acidic protein, all lines except D-245 MG are tumorigenic in athymic mice, and each line displays a unique pattern with respect to in vitro growth parameters and expression of biochemically defined markers, oncofetal antigens and lymphoid-associated markers. D-245 MG and D-259 MG are able to grow in the absence of supplemental glutamine; glutamine synthetase was detected in these cell lines both by immunocytochemistry and by direct assay. Thus, the four permanent human glioma-derived cell lines described here are representative of glioma lines in their general characteristics. D-259 MG retains numerous double minute chromosomes (DMs), D-263 MG contains two marker chromosomes with breaks in 9p, and D-247 MG and D-245 MG with stemlines containing 96 and 89 chromosomes contain eight and six normal copies (respectively) of chromosome No. 7. The retention in these four cell lines of the most common chromosomal abnormalities seen in biopsies of malignant human gliomas provides the opportunity to investigate the meaning of these specific chromosomal changes.

Animals↗

Intracytoplasmic sperm injection (ICSI) and chromosomally abnormal spermatozoa.

An infertile couple was referred for intracytoplasmic sperm injection (ICSI) because of primary infertility and oligoasthenoteratozoospermia (OAT) in the male. It was observed that although the sperm cells presented with an unusual head size and multiple tails they were able to fertilize the oocytes after ICSI. Subsequent molecular cytogenetic analysis demonstrated de-novo chromosome abnormalities in virtually all sperm cells with 40% diploidy and 24% triploidy in addition to aneuploidy for the sex chromosomes.

Adult↗

Hyponatremia secondary to reset osmostat in a child with a central nervous system midline defect and a chromosomal abnormality.

A newborn with a CNS midline defect and persistent hyponatremia was diagnosed with a "reset" osmostat using a 3% hypertonic saline test. The diagnosis was established by measuring urinary arginine vasopressin (UAVP) and plasma osmolality (P(Osmoil)). In this infant a chromosome abnormality with the karyotype 46, X, -X, +der(X) t(X;13) (p22.1;q22) was associated with the midline defect and a reset osmostat.

Arginine Vasopressin↗

Low p53 expression of acute myelocytic leukemia cells with t(8;21) chromosome abnormality: association with low p14(ARF) expression.

In this study, the mRNA expression of p14(ARF) in t(8;21)AML cells was found to be significantly lower than acute myelocytic leukemia (AML) cells without t(8;21) chromosome abnormality, which was concordant with previous observation by Linggi et al. that AML1-MTG8 represses the transcription of p14(ARF). Although p53 mRNA expression level of t(8;21)AML cells was not low, p53 protein expression was reduced in t(8;21)AML cells. Genotoxic damage by ionizing radiation did not induce p53 upregulation in t(8;21)AML cells. Since p14(ARF) has been demonstrated to inhibit p53 degradation by binding to MDM2, repression of p14(ARF) expression in t(8;21)AML may facilitate the degradation of p53 by MDM2. Low p14(ARF) in t(8;21)AML may also account for the absence of upregulation of p53 by ionizing radiation. Then, we have shown that p53 expression level was inversely correlated with S/G2/M population of cell cycle in AML cells. Most of the t(8;21)AML are considered to be in p53(low) S/G2/M(high). It is now widely known that formation of AML1-MTG8 by t(8;21) translocation is a very early event in leukemogenesis, and AML1-MTG8 alone might have limited proliferative potential. Then, secondary oncogenic events such as activated receptor tyrosine kinase (like c-kit mutation), is necessary to become full-blown leukemia. Low p53 protein expression and insufficient induction of p53 by genotoxic damage might increase the opportunity to obtain additional oncogenic events, since genome guard function of p53 does not work in t(8;21)AML cells.

Cell Cycle↗