Chromosome aberrations

One of the most frequently used alkylating drugs in the therapy of a broad spectrum of tumors is cyclophosphamide. To elucidate the mechanisms by which tumor cells acquire resistance to this agent, Chinese hamster ovary cells (CHO-K1) were treated with a high dose of the cyclophosphamide analogue mafosfamide, and survivors were analyzed as to their cell killing response, chromosomal aberrations, and DNA repair capacity. None of the surviving clones tested were mafosfamide resistant. Surprisingly, some of the isolated cell lines exhibited a mafosfamide-hypersensitive phenotype. Two of these cell variants (designated as CHO-K1-4 and CHO-K1-12) were analyzed in more detail and proved to be cross-sensitive to other DNA cross-linking antineoplastic drugs such as N-hydroxyethyl-N-chloroethylnitrosourea, treosulfan, melphalan, cisplatin, and mitomycin C. The hypersensitivity to the cytotoxic effect of mafosfamide was accompanied by a 2-3-fold increase in the frequency of chromosomal aberrations. The intracellular levels of glutathione and glutathione S-transferase activity of the hypersensitive variants as well as growth rate were comparable to wild-type cells. Both the variant and the parental cells did not exhibit an increase in the amount of p53 upon UV irradiation. Furthermore, sensitive cells displayed similar UV-induced unscheduled DNA synthesis and showed identical amounts of ERCC1 mRNA as wild-type cells, indicating that the hypersensitive phenotype is not due to a defect in nucleotide excision repair. The induction of DNA single-strand breaks upon mafosfamide treatment was very similar in wild-type and mutants, and the removal of mafosfamide-induced DNA cross-links was not reduced in hypersensitive cells. However, the hypersensitive cell variants exhibited a less severe drug-induced block to DNA replication. From the data obtained, we conclude that hypersensitivity to cross-linking agents upon mafosfamide selection is due to changes in cell cycle progression of drug-treated cells.

Autism is a genetic neurodevelopmental disorder of unknown cause and pathogenesis. The identification of genes involved in autism is expected to increase our understanding of its pathogenesis. Infrequently, neurodevelopmental disorders like autism are associated with chromosomal anomalies. To identify candidate genes for autism, we initiated a positional cloning strategy starting from individuals with idiopathic autism carrying a de novo chromosomal anomaly. We report on the clinical, cytogenetic and molecular findings in a male person with autism, no physical abnormalities and normal IQ, carrying a de novo balanced paracentric inversion 46,XY,inv(10)(q11.1;q21.3). The distal breakpoint disrupts the TRIP8 gene, which codes for a protein predicted to be a transcriptional regulator associated with nuclear thyroid hormone receptors. However, no link between thyroid gland and autism has been reported so far. In addition, the same breakpoint abolishes expression of a nearby gene, REEP3, through a position effect. Receptor Expression-Enhancing Proteins (REEP) 3 is one of the six human homologs of yeast Yop1p, a probable regulator of cellular vesicle trafficking between the endoplasmatic reticulum and the Golgi network. These observations suggest that TRIP8 and REEP3 are both positional candidate genes for autism. In addition, our data indicate that in the selection of positional candidate genes when studying chromosomal aberrations, position effects should be taken into account.

Karathane LC (active ingredient dinocap), a contact fungicide and a non-systemic acaricide was investigated for its ability to induce chromosome aberrations (CAs) and sister chromatid exchanges (SCEs) in cultured human lymphocytes of peripheral blood. In addition to the cytogenetic analysis, the effect of karathane LC on the cell proliferation kinetics (CPK) by the replication index (RI) was studied. The mitotic index (MI) was also determined to detect the cytotoxic effect. Lymphocytes were treated with four different concentrations (5, 10, 15 and 20 mg/ml) of karathane LC for 24 and 48 h. Significant differences between exposed and non-exposed groups found in CAs, SCEs and MI demonstrate the mutagenic, clastogenic and also the cytotoxic effect of karathane LC.

DNMT3A mutations are associated with poor prognosis in acute myeloid leukemia (AML), but the stability of this mutation during the clinical course remains unclear. In the present study of 500 patients with de novo AML, DNMT3A mutations were identified in 14% of total patients and in 22.9% of AML patients with normal karyotype. DNMT3A mutations were positively associated with older age, higher WBC and platelet counts, intermediate-risk and normal cytogenetics, FLT3 internal tandem duplication, and NPM1, PTPN11, and IDH2 mutations, but were negatively associated with CEBPA mutations. Multivariate analysis demonstrated that the DNMT3A mutation was an independent poor prognostic factor for overall survival and relapse-free survival in total patients and also in normokaryotype group. A scoring system incorporating the DNMT3A mutation and 8 other prognostic factors, including age, WBC count, cytogenetics, and gene mutations, into survival analysis was very useful in stratifying AML patien...

We report evaluation in rhesus monkeys of a flow cytometric procedure (MicroFlow) that has previously been shown to allow assessment of micronucleated reticulocytes (MN-RETs) in the peripheral blood of rats and dogs. Reticulocytes (RETs) were labeled with anti-CD71-fluorescein isothiocyanate, DNA was stained with propidium iodide using RNase treatment, and anti-CD61-phycoerythrin was used to reduce interference from platelets. Flow cytometric data were compared with microscopic scores of peripheral blood and bone marrow using standard acridine orange staining. A single iv administration of cyclophosphamide (CP, 5 mg/kg) induced an approximately 10-fold increase in blood MN-RET frequency, with the peak occurring 2 days after administration. After daily CP treatment to approximate a steadystate condition, the frequency of MN-RETs in peripheral blood was approximately 25% of that in bone marrow, indicating strong selection against MN-RETs. Nonetheless, CP-treated animals exhibited markedly elevated blood MN-RET values (2.45-3.99%, n 5 3; compared to a mean baseline of 0.12%, n 5 6). These measurements closely reflected the increased frequencies observed in the bone marrow compartment (Spearman correlation coefficient 5 0.9856, n 5 6). These data suggest that MN-RET measurements in blood are suitable for assessing chemicalinduced chromosomal damage and can be readily integrated into routine toxicity tests, allowing genotoxicity data to be obtained as an integral part of toxicity evaluations. Microscopy-based scoring is challenging due to the low frequency of RETs and MN-RET in monkeys, but sufficient numbers of cells are easily scored with the flow cytometric procedure.

Purpose: Two quality controlled inter-laboratory exercises were organized within the EU project 'Realizing the European Network of Biodosimetry (RENEB)' to further optimize the dicentric chromosome assay (DCA) and to identify needs for training and harmonization activities within the RENEB network. Materials and methods: The general study design included blood shipment, sample processing, analysis of chromosome aberrations and radiation dose assessment. After manual scoring of dicentric chromosomes in different cell numbers dose estimations and corresponding 95% confidence intervals were submitted by the participants. Results: The shipment of blood samples to the partners in the European Community (EU) were performed successfully. Outside the EU unacceptable delays occurred. The results of the dose estimation demonstrate a very successful classification of the blood samples in medically relevant groups. In comparison to the 1st exercise the 2nd intercomparison showed an improvement in the accuracy of dose estimations especially for the high dose point. Conclusions: In case of a large-scale radiological incident, the pooling of ressources by networks can enhance the rapid classification of individuals in medically relevant treatment groups based on the DCA. The performance of the RENEB network as a whole has clearly benefited from harmonization processes and specific training activities for the network partners.

Purpose: In the framework of the 'Realizing the European Network of Biodosimetry' (RENEB) project, two intercomparison exercises were conducted to assess the suitability of an optimized version of the cytokinesis-block micronucleus assay, and to evaluate the capacity of a large laboratory network performing biodosimetry for radiation emergency triages. Twelve European institutions participated in the first exercise, and four non-RENEB labs were added in the second one. Materials and methods: Irradiated blood samples were shipped to participating labs, whose task was to culture these samples and provide a blind dose estimate. Micronucleus analysis was performed by automated, semi-automated and manual procedures. Results: The dose estimates provided by network laboratories were in good agreement with true administered doses. The most accurate estimates were reported for low dose points ( 0.94 Gy). For higher dose points (! 2.7 Gy) a larger variation in estimates was observed, though in the second exercise the number of acceptable estimates increased satisfactorily. Higher accuracy was achieved with the semi-automated method. The results of the two exercises performed by our network demonstrate that the micronucleus assay is a useful tool for large-scale radiation emergencies, and can be successfully implemented within a large network of laboratories.

To further investigate the possible relationships between agricultural pesticide exposure and the increased risk of non-Hodgkin's Lymphoma among farm workers in the north central United States, we performed G-banded chromosome analyses of peripheral blood from workers classified according to primary types of pesticide exposure: herbicides (n = 20), insecticides (n = 18), fumigants (n = 23), and occupationally unexposed controls (n = 33). Significantly increased rearrangement frequencies were demonstrated in fumigant and insecticide appliers compared to control subjects. At certain chromosome bands there were significant excesses of breaks observed in pesticide appliers, but no breaks were observed in controls. Some of these bands contained genes with potential implications for cancer risk, including oncogenes and genes involved in tumor suppression and apoptosis. Of particular interest with regard to lymphoma risk were the excess rearrangement and breaks involving band 14q32 in fumigant appliers and the excess breaks involving band 18q21 in herbicide appliers; translocations linking 14q32 and 18q21 are the most common rearrangements observed in non-Hodgkin's lymphoma patients. The potential pathobiological relevance of these cytogenetic events warrants additional investigation at the molecular level.

Imidacloprid (IMI) is a neonicotinoid insecticide widely used in agricultural activities all around the world. This compound is transported from croplands to surrounding freshwater ecosystems, producing adverse effects on nontarget organisms. Because of the relevance of aquatic macrophytes in the above-mentioned environments and the lack of studies of potential effects of IMI on them, this work aimed to assess the mitotic process and potential genotoxicity in the aquatic macrophyte Bidens laevis L. Although the analysis of the Mitotic Index (MI) showed that IMI was not cytotoxic, the Cell Proliferation Kinetics (CPK) frequencies evidenced modifications in the kinetics of the mitotic process. Indeed, the anaphases ratio decreased at 10 and 100 μg/L IMI, while at 1000 μg/L an increase of prophases ratio and a decrease of metaphases ratio were observed. Regarding genotoxicity, IMI produced an increase of the abnormal metaphases frequency from 10 μg/L to 1000 μg/L as well as an increase in clastogenic anaphases-telophases frequency at 100 and 1000 μg/L. In addition, aneugenic anaphases-telophases and C-mitosis frequencies also increased at 1000 μg/L, confirming the effects on the mitotic spindle. Considering the genotoxic effects on B. laevis through two different mechanisms (aneugenic and clastogenic) and the wide spread use of IMI in agriculture, these mechanisms of toxicity on macrophytes should be considered among other recognized effects of this insecticide on aquatic biota.

High-resolution oligonucleotide array comparative genomic hybridization (aCGH) and spectral karyotyping (SKY) were applied to a panel of malignant mesothelioma (MMt) cell lines. SKY has not been applied to MMt before, and complete karyotypes are reported based on the integration of SKY and aCGH results. A whole genome search for homozygous deletions (HDs) produced the largest set of recurrent and non-recurrent HDs for MMt (52 recurrent HDs in 10 genomic regions; 36 non-recurrent HDs). For the first time, LINGO2, RBFOX1/A2BP1, RPL29, DUSP7, and CCSER1/FAM190A were found to be homozygously deleted in MMt, and some of these genes could be new tumor suppressor genes for MMt. Integration of SKY and aCGH data allowed reconstruction of chromosomal rearrangements that led to the formation of HDs. Our data imply that only with acquisition of structural and/or numerical karyotypic instability can MMt cells attain a complete loss of tumor suppressor genes located in 9p21.3, which is the most frequently homozygously deleted region. Tetraploidization is a late event in the karyotypic progression of MMt cells, after HDs in the 9p21.3 region have already been acquired.

It has become increasingly clear that the cells within the tumor microenvironment play a critical role in cancer growth and metastasis. Studies in experimental models suggest that carcinoma-associated fibroblasts (CAF) differ from normal fibroblasts and are capable of promoting cancer progression through a variety of mechanisms. At present, a definitive view is lacking on whether genomic abnormalities are present and whether they might underlie the observed phenotypic differences. This study reports the molecular analysis of the largest series of breast CAFs reported to date, with an array comparative genomic hybridization–based DNA copy number analysis of cultured CAFs derived from 25 freshly resected human breast cancers. We found DNA copy number changes consisting of the whole arm of chromosomes 6p and 9p plus interstitial 4q loss in only one sample. No abnormalities were observed in non–tumor-associated fibroblast counterparts. Karyotyping of the same CAF revealed further chromo...

Cancer cells overcome replicative senescence by exploiting mechanisms of telomere elongation, a process often accomplished by reactivation of the enzyme telomerase. However, a subset of cancer cells lack telomerase activity and rely on the alternative lengthening of telomeres (ALT) pathway, a recombination-based mechanism of telomere elongation. Although the mechanisms regulating ALT are not fully defined, chronic replication stress at telomeres might prime these fragile regions for recombination. Here, we demonstrate that the replication stress response protein SMARCAL1 is a critical regulator of ALT activity. SMARCAL1 associates with ALT telomeres to resolve replication stress and ensure telomere stability. In the absence of SMARCAL1, persistently stalled replication forks at ALT telomeres deteriorate into DNA double-strand breaks promoting the formation of chromosome fusions. Our studies not only define a role for SMARCAL1 in ALT telomere maintenance, but also demonstrate that resolution of replication stress is a crucial step in the ALT mechanism.

Additional chromosomal abnormalities are currently detected in Burkitt's lymphoma. They play major roles in the progression of BL and in prognosis. The genes involved remain elusive. A whole-genome oligonucleotide array CGH analysis correlated with karyotype and FISH was performed in a set of 27 Burkitt's lymphoma-derived cell lines and primary tumors. More than half of the 145 CNAs,2 Mb were mapped to Mendelian CNVs, including GSTT1, glutathione s-transferase and BIRC6, an anti-apoptotic protein, possibly predisposing to some cancers. Somatic cell line-specific CNVs localized to the IG locus were consistently observed with the 244 K aCGH platform. Among 136 CNAs .2 Mb, gains were found in 1q (12/27), 13q (7/27), 7q (6/27), 8q(4/27), 2p (3/27), 11q (2/27) and 15q (2/27). Losses were found in 3p (5/27), 4p (4/27), 4q (4/27), 9p (4/27), 13q (4/27), 6p (3/27), 17p (3/27), 6q (2/27),11pterp13 (2/27) and 14q12q21.3 (2/27). Twenty one minimal critical regions (MCR), (range 0.04-71.36 Mb), were delineated in tumors and cell lines. Three MCRs were localized to 1q. The proximal one was mapped to 1q21.1q25.2 with a 6.3 Mb amplicon (1q21.1q21.3) harboring BCA2 and PIAS3. In the other 2 MCRs, 1q32.1 and 1q44, MDM4 and AKT3 appeared as possible drivers of these gains respectively. The 13q31.3q32.1 ,89.58-96.81. MCR contained an amplicon and ABCC4 might be the driver of this amplicon. The 40 Kb 2p16.1 ,60.96-61. MCR was the smallest gained MCR and specifically encompassed the REL oncogene which is already implicated in B cell lymphomas. The most frequently deleted MCR was 3p14.1 ,60.43-60.53. that removed the fifth exon of FHIT. Further investigations which combined gene expression and functional studies are essential to understand the lymphomagenesis mechanism and for the development of more effective, targeted therapeutic strategies.

Small supernumerary marker chromosomes (sSMCs) are a major problem in prenatal cytogenetic diagnostics. Over twothirds of cases carrying an sSMC derived from chromosome 1 are associated with clinical abnormalities. We report 3 further cases of such sSMCs that did not show any clinical abnormalities. All 3 sSMCs studied were detected prenatally and characterized comprehensively for their genetic content by molecular cytogenetics using subcentromere-specific multicolor fluorescence in situ hybridization, and for a possibly associated uniparental disomy. After exclusion of additional euchromatin due to the presence of sSMCs and a uniparental disomy, parents opted for continuation of the pregnancies and healthy children were born in all 3 cases. It is important to quickly and clearly characterize prenatal sSMCs. Also, all available sSMC cases need to be collected on a homepage such as the Jena Institute of Human Genetics and Anthropology sSMC homepage (

Sixteen newly established cell lines with small supernumerary marker chromosomes (sSMC) derived from chromosomes 1, 2, 4, 6, 7, 8, 14, 15, 16, 18, 19, 21, and 22 are reported. Two sSMC are neocentric and derived from 15q24.1-qter and 2q35-q36, respectively. Two further cases each present with two sSMC of different chromosomal origin. sSMC were characterized by multicolor fluorescence in situ hybridization for their chromosomal origin and genetic content. Moreover, uniparental disomy of the sister chromosomes of the sSMC was excluded in all nine cases studied for that reason. The 16 cases provide information to establish a refined genotype-phenotype correlation of sSMC and are available for future studies.

Small supernumerary marker chromosomes (SMCs) are present in about 0.05% of the human population. In approximately 30% of SMC carriers (excluding the ~60% SMC derived from one of the acrocentric chromosomes), an abnormal phenotype is observed. The clinical outcome of an SMC is difficult to predict as they can have different phenotypic consequences because of (1) differences in euchromatic DNA-content, (2) different degrees of mosaicism, and/or (3) uniparental disomy (UPD) of the chromosomes homologous to the SMC. Here, we present 35 SMCs, which are derived from all human chromosomes, apart from chromosome 6, as demonstrated by the appropriate molecular cytogenetic approaches, such as centromere-specific multicolor fluoresence in situ hybridization (cenM-FISH), multicolor banding (MCB), and subcentromere-specific multicolor FISH (subcenM-FISH). In nine cases without an aberrant phenotype, neither partial proximal trisomies nor UPD could be detected. Abnormal clinical findings, such as psychomotoric retardation and/ or craniofacial dysmorphisms, were associated with seven of the cases in which subcentromeric single-copy probes were proven to be present in three copies. Conversely, in eight cases with a normal phenotype, proximal euchromatic material was detected as partial trisomy. UPD was studied in 12 cases and subsequently detected in two of the cases with SMC (partial UPD 4p and maternal UPD 22 in a der( )-syndrome patient), indicating that SMC carriers have an enhanced risk for UPD. At present, small proximal trisomies of 1p, 1q, 2p, 6p, 6q, 7q, 9p, and 12q seem to lead to clinical manifestations, whereas partial

Unbalanced chromosomal abnormalities (UBCA) are reported for >50 euchromatic regions of almost all human autosomes. UBCA are comprised of a few megabases of DNA, and carriers are in many cases clinically healthy. Here we report on a partial trisomy of chromosome 4 of the centromere-near region of the short arm of chromosome 4 present as a small supernumerary marker chromosome (sSMC). The sSMC was present in >70% of amnion cells and in 60% of placenta. Further delineation of the size of the duplicated region was done by molecular cytogenetics and array comparative genomic hybridization. Even though the sSMC lead to a partial trisomy of ∼9 megabase pairs, a healthy child was born, developing normally at 1 year of age. No comparable cases are available in the literature. Thus, we discuss here the possibility of having found a yet unrecognized chromosomal region subject to UBCA.

© F e r r a t a S t o r t i F o u n d a t i o n © F e r r a t a S t o r t i F o u n d a t i o n © F e r r a t a S t o r t i F o u n d a t i o n that once CCyR has been reached, achieving deeper molecular response is associated with a better EFS and FFS, and that CMR clearly confers the best outcome and should thus become the main objective of CML therapies.

We have studied the pattern of chromosome instability in cultured fibroblasts and fetal membrane cells from a fetus aborted by an individual with a history of a previous child affected with Fanconi anemia (FA). These cells exhibited a low level of spontaneous chromosome instability. Upon treatment with diepoxybutane (DEB), chromosome breakage increased to a level comparable to that reported earlier in DEB-treated FA heterozygous cells. Cultured cells derived from chromosomally normal fetuses which served as controls did not show DEB-induced chromosome breakage. This observation suggests that the fetus studied is heterozygous for the FA gene. The ability to distinguish readily between the three genotypes (homozygous FA, heterozygous FA, and normal) in an in vitro stress system that measures the response of the cells to a clastogenic agent makes available a test for the prenatal and postnatal detection of the FA gene.

Fanconi anemia is characterized by congenital abnormalities, bone marrow failure, and cancer predisposition. To investigate the origin, functional role, and clinical impact of FANCA mutations, we determined a FANCA mutational spectrum with 130 pathogenic alleles. Some of these mutations were further characterized for their distribution in populations, mode of emergence, or functional consequences at cellular and clinical level. The world most frequent FANCA mutation is not the result of a mutational “hot-spot” but results from worldwide dissemination of an ancestral Indo-European mutation. We provide molecular evidence that total absence of FANCA in humans does not reduce embryonic viability, as the observed frequency of mutation carriers in the Gypsy population equals the expected by Hardy-Weinberg equilibrium. We also prove that long distance Alu-Alu recombination can cause Fanconi anemia by originating large interstitial deletions involving FANCA and 2 adjacent genes. Finally, we...

We have constructed novel DNA substrates (one inverted and three direct repeats) based on the same 0.6-kb repeat sequence to study deletions and inversions in Saccharomyces cerevisiae. Spontaneous deletions occur six to eight times more frequently than inversions, irrespective of the distance between the repeats. This difference can be explained by the observation that deletion events can be mediated by a recombination mechanism that can initiate within the intervening sequence of the repeats. Spontaneous and double-strand break (DSB)-induced deletions occur as RAD52-dependent and RAD52-independent events. Those deletion events initiated through a DSB in the unique intervening sequence require the Rad1/Rad10 endonuclease only if the break is distantly located from the flanking DNA repeats. We propose that deletions can occur as three types of recombination events: the conservative RAD52-dependent reciprocal exchange and the nonconservative events, one-ended invasion crossover, and s...

The management of Wilms' tumors consists of a combination of surgery, chemotherapy, and possibly radiotherapy. To date, chemotherapy is being risk stratified according to histologic subtype and stage. Although the cytogenetic characteristics of Wilms' tumors are well established, the cytogenetic effects related to chemotherapy are widely unknown. We herein report on comparative genomic hybridization findings in 41 primary Wilms' tumors of blastemal type, of which 19 had received preoperative chemotherapy (PCT group) and 22 did not (non-PCT group). Overall, imbalances could be detected in 32 tumors, with +1q (17 cases), +7q (10 cases), +7p (6 cases), and −7p (6 cases) as the most common changes. Among these, +7q and −7p were both significantly associated with metastatic disease at the time of surgery (P = 0.002 and 0.007, respectively), and +7q was also associated with higher stage (stages III + IV; P = 0.003). There were significant differences in the cytogenetic constit...

There are reports showing association of fragile X with trisomy 21, Klinefelter syndrome, triple X, Duchenne muscular dystrophy (DMD) and familial psychiatric disorder(l-5). In this report we describe a case of fragile X associated with 'clinical features of deletion 9p syndrome'.

Various heteromorphisms of the 9q hetero- chromatic area have been reported. In most instances, the extra G positive band is accompanied by an extra C band. We describe a family where the extra G band is totally euchromatic and does not include an extra C band. It is not clear whether these two types of variant chromosome 9 arose from a similar mechanism. (I Med Genet 1993;30:613) In recent years, there have been reports of rare variant chromosome 9. Roland et all reported two unrelated families with an inherited chro- mosome 9 where an extra G positive band was found adjacent to the heterochromatic region of the long arm. Previously Luke et al described a similar chromosome in a patient with mental retard- ation and behavioural problems. The mother's karyotype was normal and the father was unavailable for analysis. Thus it is not possible to exclude that this chromosome 9 was inherited and the observed phenotype might not be the result of the abnormal chromosome 9.

Clonal chromosomal abnormalities in Ph-negative cells (CCA/Ph-) have been identified in 3-15% of chronic myeloid leukemia (CML) patients with a partial or complete cytogenetic response (CCyR) to imatinib(1). Trisomy 8 and deletions of chromosome 7 [either monosomy 7 or del 7(q)] account for the majority of cases, although a range of other

status in breast carcinoma is essential for therapy planning. Clinical assays are targeted at protein overexpression (immunohistochemical analysis) or gene amplification (fluorescence in situ hybridization [FISH]). Cases with aberrant FISH signal patterns are problematic and may lead to underreporting of Her-2/neu amplification. We performed FISH with additional chromosome 17 probes, SMS (Smith-Magenis syndrome critical region) and RARA (retinoic acid receptor), on 7 cases with unusual Her-2/CEP17 (chromosome 17 centromere control probe) results to assess whether different measurements of chromosome 17 copy number might clarify the Her-2/neu amplicon status. Although the Her-2/CEP17 ratio scores were within normal range (<2.0), the Her-2/SMS or Her-2/RARA ratio revealed amplification of Her-2/neu in 5 of 7 cases. Immunohistochemical analysis demonstrated Her-2/neu protein overexpression in the same 5 cases only. We describe novel application of SMS/RARA FISH probes for assessing cases with complex Her-2/CEP17 FISH patterns. Such additional data, correlated with immunohistochemical analysis, may help guide therapy in patients with breast carcinoma.

The potential of cytologically reconstructed barley line D-2946 to cope with the major lesions that hamper genome integrity, namely DNA single-and double-strand breaks was investigated. Strand breaks induced by γ-rays and Li ions were assessed by neutral and alkaline comet assay. Repair capacity after bleomycin treatment was evaluated by agarose gel electrophoresis under neutral and alkaline conditions. Frequencies of radiation-induced chromosome aberrations were also determined. Results indicate that radiation-mediated constitutive rearrangement of the chromosome complement has led to a substantial modulation of the sensitivity of barley genome towards DNA strand breaks, produced by ionising radiation, Li ion implantation and bleomycin in an agent-specific manner, as well as of the clastogenic response to γ-rays. Based on these findings, reconstructed barley karyotype D-2946 can be considered a candidate radio-sensitive line with reduced ability to maintain genome integrity with respect to both DNA and chromosomal damage.

ALL is the most common childhood malignancy and identification of prognostic factors is important for further improvement of the treatment outcome in this fatal disease. Cytogenetic changes and MRD are the most powerful prognostic factors in ALL. We identified significant correlations between some CD markers and cytogenetic subgroups which can be used in MRD monitoring and as potential therapy targets. Background: Identification of prognostic factors in acute lymphoblastic leukemia (ALL) patients is important for stratifying patients into risk groups and tailoring treatment accordingly. Molecular and cytogenetic abnormalities are the most important prognostic factors. Minimal residual disease (MRD) is also an important predictor of relapse in ALL. However, the correlation of both prognostic variables has not been thoroughly studied. Methods: We investigated the correlation between defined cytogenetic abnormalities and selected new MRD markers (CD79b, CD123, and CD200) in 56 newly diagnosed Egyptian pediatric B-cell ALL patients. Results: CD123 found to be expressed in 45% of patients, CD200 in 80.3%, and CD79b in 67.9%. MRD analysis during treatment showed stable expression patterns of CD200. There was significant association of CD123 expression with the hyperdiploid ALL group (P ¼ .017). Another association (P ¼ .029) was found between CD79b negativity and the t(12;21) group. CD200 was widely expressed in all groups. Conclusion: There is a significant correlation between some markers, and certain ALL recurrent cytogenetic subgroups (CD123 and hyperdiploidy, CD79b negativity, and ETV-RUNX1 group) have good prognostic value. CD200 can be used as MRD markers in ALL patients and can also can serve as therapy targets.

Stomach cancer is the fourth most common type of cancer cancer and the second leading cause of cancer-related death through the world. The objective of the present study is to know the chromosomal aberrations in peripheral blood of stomach cancer patients. The present study was carried out on 50 patients who were suffering from stomach cancer in Erbil city and 25 healthy individuals as a control group in both sex and different age groups. Blood samples were collected and chromosomal study was performed. Because stomach cancer is a heterogeneous disorder; genetic factors, smoking habit, alcohol habit, Helicobacter pylori ( H .pylori) bacterial infection and various environmental factors contribute to its development. Other factors was also studied included patient gender , age and blood groups. The results of the present study suggest that highest value of chromosomal aberrations was (Dicentric chromosome) which occurred in males at fifth age group (65-74) ,also shown that most patients are males at age group(45-64), most of them have smoking and alcohol habit with Helicobacter pylori( H .pylori) bacterial infection and most patients are A blood type .

L iver cancer is the sixth most frequent cancer and the second leading cause of cancer death through the world. The first objective of the present study is to know the chromosomal aberrations in peripheral blood of liver cancer patients. The present study was carried out on 50 patients who were suffering from liver cancer in Erbil city and 25 healthy individuals as a healthy group in both sex and different age groups. The second objective of the present study is to know the mutations in TP53 tumor suppressor gene, so molecular study was carried out on 18 patients who were suffering from liver cancer in Erbil city and 1 healthy individual as a control group. Detection a mutation in TP53 gene in peripheral blood cells may be helpful to the diagnosis of liver cancer, especially to the accurate staging of liver cancer. Additionally, cytogenetic study followed by molecular analysis of recurring chromosome changes has facilitated the identification of crucial ontogenesis and tumor suppressor genes. The mechanism of liver carcinogenesis involve multiple endogenous and exogenous genetic alterations, so many factors contribute to its development such as genetic factors, Hepatitis Band C virus infections, smoking habit and alcohol habit. Other factors was also studied included patient gender and age. The results of the present study suggest that highest value of chromosomal aberrations was (Dicentric chromosome) which occurred in males at fifth age group (65-74) , also shown that most patients are males at age group(65-74), most of them have smoking , alcohol habit and Hepatitis B viral infection. From the study of TP53 gene, we observed mutation in exon 7 which was deletion of nitrogen base G , just before the coding region , which represent splice-site mutation.