Abnormalities of chromosome 1 in relation to human malignant diseases

Acute Panmyelosis with Myelofibrosis: Clinical, Immunophenotypic and Cytogenetic Study of Twelve Cases

The clinical, cytogenetic, and immunophenotypic features in 12 adult patients with acute panmyelosis with myelofibrosis (APMF; ICD-0-3: 9931/3; C42.1) are reported (median age: 57 years; f/m = 1.4). The white cell count (WBC) was normal in 3 patients; 9 had leucopenia. The median hemoglobin value was 64.5 g/l, and median platelet count 12 x 10(9)/l. Bone marrow biopsy showed a hypercellular marrow in 10/12 patients with a significant infiltration of pathological blasts (range: 30 - 60%). All the cases had marked reticulin fibrosis. Immunophenotyping of bone marrow blast cells showed the expression of early (CD34) and lineage-unspecified antigens (HLA-DR) in 6/7, and 7/7 patients, respectively. "Early" myeloid antigens (CD13, CD33) were seen in 6/7 and 4/6 patients respectively. Monocyte antigen (CD14) was expressed in 3/7 patients. Megakaryocyte antigen (CD61) and erythroid cell antigen (GpA) were each expressed in only 1 patient. Two patients had expression of CD34, HLA-DR and "early" myeloid antigens by their bone marrow blast cells and 1 of these also had a co-expression of the antigens from a differentiated monocytic cell proliferation (lysozyme+, CD68+). Nonspecific chromosomal aberrations were recorded in 8/10 patients. The median survival was 2 months. These findings suggest an immature myeloid phenotype of blast cells in APMF. In 6/9 patients a leukemic cell differentiation into monocytic, megakaryocytic or erythroid lineage was also demonstrated.

Abnormalities of chromosome 1p/q are highly associated with chromosome 13/13q deletions and are an adverse prognostic factor for the outcome of high-dose chemotherapy in patients with multiple myeloma

The prognostic value of chromosomal abnormalities was studied in untreated multiple myeloma patients who were registered into a prospective randomised multicentre phase 3 study for intensified treatment (HOVON24). A total of 453 patients aged less than 66 years with stage II and III A/B disease were registered in the clinical study. Cytogenetic analysis was introduced as a standard diagnostic assay in 1998. It was performed at diagnosis in 160 patients and was successful in 137/160 patients (86%). An abnormal karyotype was observed in 53/137 (39%) of the patients. Abnormalities of chromosome 1p and 1q were found in 19 (36% of patients with an abnormal karyotype) and 21 patients (40%). There was a strong association between chromosome 1p and/or 1q abnormalities and deletion of chromosome 13 or 13q (n = 27, P < 0.001). Patients with karyotypic abnormalities had a significantly shorter overall survival (OS) than patients with normal karyotypes. Complex abnormalities, hypodiploidy, chromosome 1p abnormalities, chromosome 1q abnormalities, and chromosome 13 abnormalities were associated with inferior OS on univariate analysis, as well as after adjustment for other prognostic factors. In conclusion, chromosome 13 abnormalities and chromosome 1p and/or 1q abnormalities were highly associated, and are risk factors for poor outcome after intensive therapy in multiple myeloma.

A der(14)t(1;14)(q12;p11) in chronic myelomonocytic leukemia

Duplication of the long arm of chromosome 1 (1q) is widely reported in human neoplasia, including the myelodysplastic syndromes (MDS). So far, it has not been described as a single aberration in the chronic myelomonocytic leukemia (CMML), a subtype of MDS. Rather, trisomy 1q was always a part of complex chromosome changes affecting the subtypes of MDS other than CMML. We report on a patient with CMML with an unbalanced translocation of the entire 1q onto the short arm of chromosome 14 as a sole cytogenetic abnormality. Fluorescence in situ hybridization (FISH) analysis with an alpha-satellite probe for the paracentric region of the long arm of chromosome 1 confirmed the presence of trisomy 1q in a derivative chromosome, der(14)t(1;14)(q12;p11). The discrepant results between the metaphase cytogenetics (100% abnormal) and interphase cytogenetic (71% nuclei with 3 signals) suggest that trisomy 1q, even in the absence of additional cytogenetic changes, has a sufficient leukemogenic potential to confer a proliferative advantage on hematopoietic cells committed to monocyte stemline both in vitro and in vivo. The literature data on partial and complete trisomy 1q in CMML is reviewed.

del(2)(p23) as a sole abnormality in a case of acute myeloid leukemia

We report a case of acute myeloid leukemia (AML) [FAB-M5a] showing a deletion of the short arm of chromosome 2 at band p23 as a sole abnormality in the bone marrow cells. This abnormality deserves to be considered as an established nonrandom entity in AML.

Delineation and physical separation of novel translocation breakpoints on chromosome 1p in two genetically closely associated childhood tumors

Sporadic childhood tumors associated with Beckwith-Wiedemann syndrome (BWS) all show abnormalities of the same region on chromosome 11. In addition to chromosome 11, other chromosome regions are affected in some of these tumor types. In this study we analyzed the region on chromosome 1p involved in the etiology of BWS-associated tumors, Wilms tumor, rhabdomyosarcoma, and hepatoblastoma. For this purpose we determined the location of two novel translocation breakpoints in this chromosome region in cells from a Wilms tumor and cells from a rhabdomyosarcoma. We constructed a map of the region and found that both breakpoints are separated by at least 875 kb. We identified a PAC clone which crosses the rhabdomyosarcoma breakpoint and found several exons within this clone. We established that this breakpoint is located proximal to the PAX7 gene and, therefore, identified a new region involved in the etiology of rhabdomyosarcomas.

Trisomy of the long arm of chromosome 1 resulting in a dicentric derivative (6)t(1;6) chromosome in a child with myelodysplastic syndrome following treatment for a primitive neuroectodermal tumor

We report the clinical, hematologic, and cytogenetic findings for a child with secondary myelodysplastic syndrome (MDS) after treatment for a primitive neuroectodermal tumor. At the time of conversion to MDS, conventional cytogenetics revealed an unbalanced der(6)t(1;6) that resulted in trisomy of the long arm of chromosome 1 and partial monosomy and duplication of 6p. Using alpha satellite probes, fluorescence in situ hybridization of bone marrow cells showed that the rearranged chromosome contained the centromeres of both chromosomes 1 and 6, thus forming a dic(1;6) resulting in trisomy 1q. This report is the first to describe a case of childhood secondary myelodysplastic syndrome associated with a trisomy 1q involving chromosome 6.

Identification of breakpoint cluster regions at 1p36.3 and 3q21 in hematologic malignancies with t(1;3)(p36;q21)

The reciprocal translocation t(1;3)(p36;q21) is associated with myelodysplastic syndromes (MDSs) and acute myeloid leukemia (AML) characterized by trilineage dysplasia, in particular dysmegakaryocytopoiesis, and a poor prognosis. As yet no molecular genetic analyses of the t(1;3) have been reported. In four patients with t(1;3), all of whom had AML-M4, which evolved from MDS, the breakpoints at 3q21 clustered within a 60-kb region centromeric to the breakpoint of the inv(3)(q21q26), whereas the breakpoints at 1p36 clustered within a 90-kb region at 1p36.3. The presence of novel clusters in both the 3q21 and 1p36 breakpoints (BCRs) suggests a common, underlying molecular mechanism for the development of t(1;3)-positive MDS/AML. The Ribophorin I (RPN1) gene close to the BCR at 3q21 was highly expressed without gross structural changes, whereas the GR6 gene located within the BCR at 3q21 was not expressed. No other highly expressed genes were isolated in a 150-kb region at 3q21. Thus, it is likely that a gene at 1p36.3 is activated by the translocation of the 3q21 region or a gene important for transformation lies on 3q21, outside the 150-kb region. Further characterization of the BCRs at 1p36.3 and 3q21 should provide important insights into the molecular genetic mechanisms involved in the genesis of t(1;3)-positive MDS/AML. Genes Chromosomes Cancer 27:229-238, 2000.

Alterations of chromosome arms 1p and 19q as predictors of survival in oligodendrogliomas, astrocytomas, and mixed oligoastrocytomas

PURPOSE

A recent report suggests that alterations of chromosome arms 1p and 19q are associated with chemotherapeutic response and overall survival in anaplastic oligodendroglioma patients treated with procarbazine, lomustine, and vincristine chemotherapy. We set out to further clarify the diagnostic and prognostic implications of these alterations in a broader set of diffuse gliomas, including astrocytic neoplasms and low-grade oligodendrogliomas.

PATIENTS AND METHODS

Fluorescence in situ hybridization (FISH) signals from DNA probes mapping to 1p and 19q common deletion regions were enumerated in 162 diffuse gliomas (79 astrocytomas, 52 oligodendrogliomas, and 31 mixed oligoastrocytomas), collected as part of an ongoing prospective investigation of CNS tumors.

RESULTS

The oligodendroglial phenotype was highly associated with loss of 1p (P =.0002), loss of 19q (P <.0001), and combined loss of 1p and 19q (P <.0001). Combined loss of 1p and 19q was identified as a univariate predictor of prolonged overall survival among patients with pure oligodendroglioma (log-rank, P =.03) and remained a significant predictor after adjusting for the effects of patient age and tumor grade (P <.01). This favorable association was not evident in patients with astrocytoma or mixed oligoastrocytoma.

CONCLUSION

Combined loss of 1p and 19q is a statistically significant predictor of prolonged survival in patients with pure oligodendroglioma, independent of tumor grade. Given the lack of this association in patients with astrocytic neoplasms and the previously demonstrated chemosensitivity of oligodendrogliomas, a combined approach of histologic and genotypic assessment could potentially improve existing strategies for patient stratification and management.

Jumping Translocations of Chromosome 1q in Multiple Myeloma: Evidence for a Mechanism Involving Decondensation of Pericentromeric Heterochromatin

Karyotypes in multiple myeloma (MM) are complex and exhibit numerous structural and numerical aberrations. The largest subset of structural chromosome anomalies in clinical specimens and cell lines involves aberrations of chromosome 1. Unbalanced translocations and duplications involving all or part of the whole long arm of chromosome 1 presumably occur as secondary aberrations and are associated with tumor progression and advanced disease. Unfortunately, cytogenetic evidence is scarce as to how these unstable whole-arm rearrangements may take place. We report nonrandom, unbalanced whole-arm translocations of 1q in the cytogenetic evolution of patients with aggressive MM. Whole-arm or “jumping translocations” of 1q were found in 36 of 158 successive patients with abnormal karyotypes. Recurring whole-arm translocations of 1q involved chromosomes 5,8,12,14,15,16,17,19,21, and 22. A newly delineated breakpoint present in three patients involved a whole-arm translocation of 1q to band 5q15. Three recurrent translocations of 1q10 to the short arms of different acrocentric chromosomes have also been identified, including three patients with der(15)t(1;15)(q10;p10) and two patients each with der(21)t(1;21)(q10;p13) and der(22)t(1;22) (q10;p10). Whole-arm translocations of 1q10 to telomeric regions of nonacrocentric chromosomes included der(12)t(1;12) (q10;q24.3) and der(19)t(1;19)(q10;q13.4) in three and two patients, respectively. Recurrent whole-arm translocations of 1q to centromeric regions included der(16)t(1;16)(q10;q10) and der(19)t(1;19)(q10;p10). The mechanisms involved in the 1q instability in MM may be associated with highly decondensed pericentromeric heterochromatin, which may permit recombination and formation of unstable translocations of chromosome 1q. The clonal evolution of cells with extra copies of 1q suggests that this aberration directly or indirectly provides a proliferative advantage.

Jumping Translocations of Chromosome 1q in Multiple Myeloma: Evidence for a Mechanism Involving Decondensation of Pericentromeric Heterochromatin

Karyotypes in multiple myeloma (MM) are complex and exhibit numerous structural and numerical aberrations. The largest subset of structural chromosome anomalies in clinical specimens and cell lines involves aberrations of chromosome 1. Unbalanced translocations and duplications involving all or part of the whole long arm of chromosome 1 presumably occur as secondary aberrations and are associated with tumor progression and advanced disease. Unfortunately, cytogenetic evidence is scarce as to how these unstable whole-arm rearrangements may take place. We report nonrandom, unbalanced whole-arm translocations of 1q in the cytogenetic evolution of patients with aggressive MM. Whole-arm or “jumping translocations” of 1q were found in 36 of 158 successive patients with abnormal karyotypes. Recurring whole-arm translocations of 1q involved chromosomes 5,8,12,14,15,16,17,19,21, and 22. A newly delineated breakpoint present in three patients involved a whole-arm translocation of 1q to band 5q15. Three recurrent translocations of 1q10 to the short arms of different acrocentric chromosomes have also been identified, including three patients with der(15)t(1;15)(q10;p10) and two patients each with der(21)t(1;21)(q10;p13) and der(22)t(1;22) (q10;p10). Whole-arm translocations of 1q10 to telomeric regions of nonacrocentric chromosomes included der(12)t(1;12) (q10;q24.3) and der(19)t(1;19)(q10;q13.4) in three and two patients, respectively. Recurrent whole-arm translocations of 1q to centromeric regions included der(16)t(1;16)(q10;q10) and der(19)t(1;19)(q10;p10). The mechanisms involved in the 1q instability in MM may be associated with highly decondensed pericentromeric heterochromatin, which may permit recombination and formation of unstable translocations of chromosome 1q. The clonal evolution of cells with extra copies of 1q suggests that this aberration directly or indirectly provides a proliferative advantage.

Establishment and characterization of a highly tumorigenic human diploid endometrial cancer cell line

A new cell line designated CUME-1 has been established from a poorly differentiated endometrial adenocarcinoma of the uterus. This cell line grew well without interruption for more than 88 months and 110 serial passages were successively carried out. The cells were highly tumorigenic in nude mice (85%). Repeated karyotype analyses from early (4th) to late (55th) passages of this cell line revealed a diploid stable clone in each passages without any noticeable structural or numerical aberrations. But from the 80th passage, a subpopulation with reciprocal translocation between chromosomes 1q and 9q consistently appeared and was observed in about 30% of the cells. This cell line is one of the rare examples of experimentally proved tumorigenic cells of human solid tumor origin that retains the diploid karyotype in vitro. HLA typing indicated the presence of DR4, DR13, DQ3 and DQ6. Cytosol estrogen and progesterone receptors were found both in fresh primary tumor and in this cell line. Gonadotropin-releasing hormone (Gn-RH) receptor mRNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) in cultured cells. Using the single-strand conformation polymorphism (SSCP) technique, we have screened CUME-1 cells for p53 mutation in exons 4 to 9. No mobility shift was observed. This cell line may be useful in studying the in vitro chromosomal evolution of the cell line and the in vivo properties of human endometrial adenocarcinoma.

The first recurring chromosome translocation in hepatoblastoma: der(4)t(1;4)(q12;q34)

We report four cases of hepatoblastoma with a derivative chromosome 4 from an unbalanced translocation between the long arms of chromosomes 1 and 4, an aberration reported only rarely in isolated cases of other types of neoplasms. The abnormality in three hepatoblastomas was der(4)t(1;4)(q12;q34), whereas the fourth case appeared to have a der(4)t(q25;q32). All had hyperdiploid tumor karyotypes; however, in the case with t(q25;q32), the der(4) was the only abnormality in the stemline. We speculate that the oncogenetic event in our cases may be the loss of a gene on distal 4q or their alteration by juxtaposition to 1q12 heterochromatin.

Lymphoid myelofibrosis associated with high grade B cell lymphoma of the liver: morphological, cytogenetic, and clinical features

Severe pancytopenia associated with moderate hepatosplenomegaly, increased serum lactic dehydrogenase (LDH) levels, and hypogammaglobulinemia were found in a young male patient. Bone marrow histology showed extensive fibrosis, hypoplasia of erythro- and granulocytopoiesis, and hyperplasia of megakaryocytopoiesis associated with histiocytic fat cell phagocytosis and infiltration of abnormal lymphocytes, compatible with lymphoid myelofibrosis. Striking chromosomal aberrations indicating karyotype evolution were also demonstrated by cytogenetic analyses (47, XY, +3 / 47, XY, +3, 1p+ / 46, XO, +3, 1p+, -Y). The clinical course was characterized by cyclic febrile episodes accompanied by excessive increase of serum LDH levels and leukocyte counts, and decrease of platelet counts, followed by spontaneous regression. Further diagnostic procedures, including two liver biopsies and computed tomography, did not detect any manifestation of lymphoma. Eventually, the patient developed rapidly progressive, lethal pulmonary aspergillosis. At autopsy, high grade B cell lymphoma of the liver was found. In this case, the lymphoid myelofibrosis seen on bone marrow biopsy may be considered as a manifestation of "discordant" bone marrow histology related to high grade lymphoma. With respect to the cyclic clinical course, a possible role of apoptotic mechanisms in the physiopathology of this disorder is reviewed.

A new cell line from human undifferentiated carcinoma of the ovary: establishment and characterization

A cell line designated CUMO-2 has been established from an undifferentiated ovarian carcinoma. The s.c. injection of cells into nude mice gave rise to fast-growing tumors, while the i.p. route induced a peritoneal carcinomatosis with ascites. Histopathologically, the transplanted s.c. tumors closely resembled the original tumor, but tumors developed in the peritoneal cavity were highly anaplastic. The epithelial nature of the cells was confirmed by ultrastructural analysis. Sequential cytogenetic analyses on early and late passages revealed highly aneuploid tumor cells with consistent structural aberrations of chromosomes 1, 3, 8 and 11. CUMO-2 cells were found to produce CA 125 in vitro and in vivo. Cytosol estrogen receptor (ER) was found but progesterone receptor (PR) was not measured. HLA typing indicated the presence of DR8 and DQw4. A gonadotropin-releasing hormone (Gn-RH) analog inhibited cell growth and Gn-RH receptor mRNA was detected by reverse transcription/polymerase chain reaction in this cell line. Administration of transforming growth factor beta 1 inhibited both cell growth and c-myc mRNA expression. This cell line demonstrated a conformational band shift in exon 7 of the p53 gene. It was a frameshift mutation.

Genomic instability in 1p and human malignancies

Both cytogenetic and molecular genetic approaches have unveiled non-random genomic alterations in 1p associated with a number of human malignancies. These have been interpreted to suggest the existence of cancer-related genes in 1p. Earlier studies had employed chromosome analysis or used molecular probes mapped by in situ hybridization. Further, studies of the various tumor types often involved different molecular probes that had been mapped by different technical approaches, like linkage analysis, radioactive or fluorescence in situ hybridization, or by employing a panel of mouse x human radiation reduced somatic cell hybrids. The lack of maps fully integrating all loci has complicated the generation of a comparative and coherent picture of 1p damage in human malignancies even among different studies on the same tumor type. Only recently has the availability of genetically mapped, highly polymorphic loci at (CA)n repeats with sufficient linear density made it possible to scan genomic regions in different types of tumors readily by polymerase chain reaction (PCR) with a standard set of molecular probes. This paper aims at presenting an up-to-date picture of the association of 1p alterations with different human cancers and compiles the corresponding literature. From this it will emerge that the pattern of alterations in individual tumor types can be complex and that a stringent molecular and functional definition of the role that Ip alterations might have in tumorigenesis will require a more detailed analysis of the genomic regions involved.

Derivative (6)t(1;6)(q22;p21) revealed in bone marrow cells by FISH 9 months before diagnosis of acute T-lymphoblastic leukemia

A chromosomal clone with unbalanced translocation resulting in partial trisomy of segment 1q22-qter and partial monosomy of segment 6p21-pter was revealed by fluorescence in situ hybridization (FISH) using a panel of different whole chromosome painting probes. The pathologic clone appeared after sequential chemotherapy treatment for AML-M5 when the patient was in complete remission before development of T-ALL. However, this clone was present during the whole period of treatment for T-ALL. The clone remained the only chromosomal aberration found. Breakpoints were detected more easily and more precisely with the use of the FISH technique than with G-banding only.

Cytogenetic findings in 200 patients with multiple myeloma

Cytogenetic studies were performed in 200 consecutive patients with multiple myeloma and related disorders. Structurally or numerically abnormal clones were found in 63 patients (32%), including 8 of 45 untreated patients (18%), and 55 of 155 treated patients (35%). The abnormal karyotypes generally showed numerous numerical and structural aberrations and in some patients multiple abnormal clones. The most striking feature of patients with hyperdiploid karyotypes was the finding of consistent recurring trisomies for chromosomes 3, 5, 7, 9, 11, 15, 19, and 21, cosegregating together in many cases. Monosomy for chromosome 13 was the most common chromosome loss, occurring in 18 abnormal patients (29%), while interstitial deletions involving band 13q14 occurred in an additional 9 patients, indicating a loss of all or part of chromosome 13 in a high percentage of patients with abnormal karyotypes (43%). Structural aberrations of chromosome 1 were most frequent, occurring in 30 of 63 patients (48%), and involved almost equally the short and long arms. The single most frequent chromosome breakpoint involved band 14q32 and was found in 21 patients (33%), including 11 patients with a 14q+ chromosome, 8 with t(11;14)(q13;q32), and 2 with t(8;14)(q24;132).

Rearrangement of chromosome 1 is a frequent finding in endometrial carcinoma. An in situ hybridization study in nine endometrial carcinomas

Nine endometrial carcinomas were examined for numerical aberrations of the chromosomes 1,7, and X by fluorescence in situ hybridization using highly repetitive chromosome-specific probes. In addition, a combination of a centromeric and a telomeric chromosome 1 probe was applied to detect structural chromosome 1 aberrations. Chromosome aberrations were found in six tumors. In four of these, an imbalance between 1q12 and 1p36 was detected, indicating the presence of an extra 1p- chromosome. In regard to the chromosomes 7 and X, monosomies and trisomies were found. Intratumoral genetic heterogeneity in endometrial carcinomas was detectable by FISH and flow cytometry. In conclusion, our findings confirm that chromosome 1 is frequently involved in structural chromosome changes, indicating chromosome 1 to be of importance in the evolution of endometrial carcinoma.

Study of numerical aberrations of chromosome 1 by fluorescent in situ hybridization and DNA content by densitometric analysis on (pre)-malignant cervical lesions

In an attempt to determine whether the fluorescent in situ hybridization (FISH) can be used as a rapid approach for the identification of aneuploidy in premalignant cervical smears, a centromeric probe for chromosome 1 was used. The results from the FISH experiments were compared with measurements of the overall DNA content obtained by means of an image analysis system. With progression to neoplasia, a decrease of the frequency of cells with two spots was observed, due to an increasing polysomy of chromosome 1. As far as the DNA content was concerned, an increasing DNA index and 5C-exceeding ratio (fraction of cells with a DNA content higher than 5C) was observed. Classification of the FISH results by a linear discriminant analysis revealed that 67.6% of the cases were classified in agreement with the CIN classification. These data suggest that chromosome 1 may be considered as a marker chromosome for pre-malignant cervical lesions and that the DNA content measurements are complementary to the FISH results.

A single clonal abnormality of chromosome 1 found in an adenocarcinoma of the uterus

Adenocarcinomas usually have a complex genome comprised of multiple chromosomal alterations. These neoplasms rarely express a single genomic change. We report the first case of an endometrial adenocarcinoma demonstrating a single genomic variation in chromosome 1 associated with a 2 1/2-year survival. The finding of this anomaly may be important in determining the etiology and clinical behavior of uterine malignancies.

Detection of premalignant stages in cervical smears with a biotinylated probe for chromosome 1

Fluorescence in situ hybridization with (peri-)centromeric probes is an easy method to detect numerical aberrations in nonmitotic and mitotic cells. In this study, cervical smears of premalignant and malignant stages (26 controls, 15 CIN I, 12 CIN II, and 15 CIN III cervical smears) were analyzed for the presence of numerical aberrations of chromosome 1 with a centromeric DNA probe (1q12). With more severe stages a decrease of disomy was observed, merely due to a gain of extra copies of chromosome 1; in some cases, however, monosomy was detected. The frequencies of disomy for chromosome 1 ranged from 65.3% to 95.0% in the controls, from 71.3% to 94.3% in CIN I, from 59.2% to 91.5% in CIN II, and from 23% to 96.2% in CIN III. Polysomy ranged from 0% to 5.7% in the controls, from 0% to 14.4% in CIN I, from 0.9% to 30.8% in CIN II, and from 0.8% to 69.6% in CIN III. Monosomy ranged from 2.6% to 34.1% in the controls, from 0% to 17.5% in CIN I, from 3.6% to 27.5% in CIN II, and from 0.9% to 31.4% in CIN III. The results show that screening for aneuploidy of chromosome 1 allows a good discrimination between control samples and dysplasia. These data suggest that chromosome 1 may be a marker chromosome. They are in accordance with previous cytodensitometric analyses, where already in the preneoplastic stages an increased DNA content (polyploidization with subsequent aneuploidization) is observed.

Karyotype evolution in a patient with Down syndrome and acute leukemia following a congenital leukemoid reaction

We report the serial cytogenetic study of a patient with Down syndrome who experienced a congenital leukemoid reaction, underwent a spontaneous remission within four months, and subsequently developed acute myeloid leukemia at 16 months. A blood chromosome study to rule out Down syndrome performed at age 24 days, during the leukemoid reaction, revealed a 47,XX,+21 karyotype. The diagnosis of acute leukemia was made at 16 months, at which time a chromosome study, on bone marrow, was performed. This analysis revealed a clonal karyotype of 47,XX,+21,-22,+der(22)t(1;22)(q21;q13) in all but one cell studied. The single apparently nonclonal cell showed a karyotype of 49,XX,+12,-13,-19,+der(19)t(19;?)(q11;?)x2,+21,+22. A third chromosome study at 19 months indicated the original leukemic clone with t(1;22) (q21;q13) had been replaced by the clone represented by the single cell with 49 chromosomes seen in the previous chromosome study. This case of an infant with Down syndrome and acute leukemia illustrated rapid evolution and a transitory nature to clonal chromosome aberrations while retaining AML morphology and course.

Partial trisomy 1q, an uncommon chromosomal aberration in erythroleukemia

A 2 years 4 months old boy with erythroleukemia (FAB-M6) and Down's syndrome is described. Chromosome analysis of bone marrow leukemic blasts revealed apart from the trisomy 21 a partial trisomy of the long arm of chromosome 1:1q23-->1qter in all cells and trisomy 8 mosaicism. To the best of our knowledge this is the first time that a partial trisomy of chromosome 1 in association with erythroleukemia has been described. Previous reports of other hematologic malignancies with aberrations of chromosome 1 indicate that the breakpoint 1q23 is nonrandom and that trisomies of chromosome 1 plays a crucial role in the course of development of hematologic malignancies. This could probably also be true for erythroleukemias.

Consistent chromosomal anomalies in keratinocyte cell lines derived from untreated malignant lesions of the oral cavity

Cytogenetic analysis has been carried out on 8 early passage cell lines derived from 8 untreated human oral squamous cell carcinomas. Clonal aberrations were detected in the karyotypes of each cell line. A high frequency of breakpoints were noted on chromosomes 1, 7, 8, 9, 11, and X. An isochromosome 8 was present in 6 out of 8 cell lines; isochromosome 9 (3 cell lines) and isochromosome 11 (1 cell line) were also found. In 4 out of 8 cell lines X chromosome harboured breakpoints, a novel finding in oral squamous cell carcinomas. Breakpoints were common on chromosome 1, with 1p12-p13 most frequently involved. Tandem duplication of 11q13-q23, which contains a number of growth regulatory genes, was also noted in 2 cases. We correlate the sites of proto-oncogenes and other growth control genes with chromosomal breakpoints and suggest that several of these may play a role in the pathogenesis of oral cancer.

Familial and genetic aspects of colorectal carcinogenesis

There is abundant clinical and pathological evidence which suggests that colorectal cancer arises in a sequential manner through a series of events that can be followed during the progression of the disease from early adenoma through to metastatic disease. The molecular events that are associated with the initiation and progression of the disease are gradually being unravelled. As the molecular characterisation of colorectal cancer continues, new mechanisms by which the disease progresses are becoming evident. In this short review, a brief description of current knowledge of colorectal cancer development is presented.

Genetic and molecular basis for cellular senescence

Normal human and rodent cells in culture exhibit a finite life span at the end of which they exhibit morphological changes and cease proliferating, a process termed cellular senescence or cellular aging. Many cancer cells differ from normal cells in that they do not senesce and have an indefinite life span in culture, suggesting that alterations relating to cellular senescence are involved in the neoplastic evolution of tumor cells. Recent experimental results strongly support a genetic basis for cellular senescence. Defects in the senescence program in transformed cells can be corrected by introduction of a specific chromosome from normal cells into the abnormal cells. Using this approach, possible senescence genes have been mapped to specific chromosomes. Cell cycle control genes that regulate entry into the DNA synthetic phase of the cell cycle must be altered in senescent cells. Recent findings suggest that phosphorylation of the retinoblastoma gene is altered in senescent cells. It is possible, but not yet proven, that aging at the cellular level contributes to the aging of the individual. Therefore, an understanding of cellular senescence at the genetic and molecular levels may provide new insights into both the cancer and aging processes.

Cytogenetic findings in a case of pediatric glioblastoma

We report a patient with glioblastoma multiforme (GBM) which showed stable and unstable telomeric associations involving the short arms of chromosomes 4 and 7. The karyotype was hyperdiploid, with chromosome numbers ranging from 84 to 87 in all cells, and showed a single stemline with variations in the number of marker chromosomes, teleomeric associations, and double minutes (dmin). The karyotype designation is 83-86,XX,-X,rea(X),-4,tas(4;7)(p16;?p22),der(6)t(6;?)(p21;?), -8, -9, der(9)t(9;?)(?p11;?), dup(9)(p12p23), -10 x 2, del(10)(p11), -11,del(11)(p11), -12, der(12)t(12;?) (p13;?),-13, -14 x 2,der(14)t(14;?) (p11;?), -16 x 2, -19, -21 x 2, -22 x 2, + 9-13mar, + dmin. Loss of the short arm of chromosome 10, structural aberrations of the short arm of chromosome 9, and dmin are consistent findings in GBM, whereas the high chromosome number is less common. Chromosome instability associated with the phenomenon of telomeric association/fusion has not been reported in GBM.

A single human colonic adenoma cell line can be converted in vitro to both a colorectal adenocarcinoma and a mucinous carcinoma

In a previous study, using a chemical carcinogen, we converted in vitro a non-tumorigenic cell line derived from a human colorectal diploid adenoma, designated PC/AA, into a tumorigenic cell line which, when inoculated into athymic nude mice, produced progressively growing adenocarcinomas. We now report that continuous in vitro passage of the PC/AA adenoma cell line resulted in its spontaneous transformation to a mucinous carcinoma with a modal karyotype of 51, XY, +i(Iq), +8, +9, +13, +i(13q), -21, +mar. These studies show that a single adenoma can be converted along 2 independent pathways, giving rise to either a mucinous carcinoma or an adenocarcinoma, and provide further experimental evidence for the adenoma-carcinoma sequence. Cytogenetic changes which occur along both pathways to tumorigenicity include abnormalities of chromosome I and multiple copies of chromosome 13. These abnormalities may be important in tumour development and progression in colorectal carcinogenesis.

Chromosome 1 in human colorectal tumors. Cytogenetic research on structural changes and their significance

The significance of short and long arm anomalies of chromosome 1 was investigated in 55 colorectal tumors comprising 41 carcinomas and 14 adenomas. The tumors were at various stages of transformation from adenoma to carcinoma. Our investigation was prompted by the observation of a p32-pter deletion on the short arm of chromosome 1 in a case of benign tubulovillous adenoma with mild dysplasia, as well as by frequent reports that chromosome 1 is involved in many neoplastic processes. Long arm anomalies were found in seven of the 41 carcinomas, six of which were in stage B2, and short arm anomalies in ten carcinomas at various stages. Three of the adenomas exhibited chromosome 1 anomalies, which in one case comprised a 1p32-pter deletion only. Overall, short arm anomalies especially concerned the p32-36 region. These results suggest that the cytogenetic anomalies respectively located on the short and long arms of chromosome 1 should be considered separately. Damage to the long arm might constitute a late non-specific event, whereas damage to the p32-pter region of the short arm might be involved in triggering colorectal tumor development.

Possible cellular and molecular mechanisms for asbestos carcinogenicity

Asbestos fibers may exert their carcinogenic effects on mesothelial cells and bronchial epithelial cells by direct and indirect mechanisms. Direct effects can occur following the physical interaction of fibers with target cells or by the generation of free radicals from the fiber surface; indirect effects, following the interaction of fibers with inflammatory cells can result in the production of cellular mediators such as cytokines and various reactive oxygen species. As a result, target cells may be induced to proliferate and/or sustain genetic alterations, which lead to tumor development.

Genomic organization and chromosomal localization of the human CTP synthetase gene (CTPS)

To elucidate the organization of the human genomic sequences encoding CTP synthetase (CTPS), fragments homologous to the cDNA were isolated from genomic lambda libraries. The fragments cloned were overlapping and cover over 40 kb. Cotransfection of the DNAs into CTPS-deficient, cytidine-requiring CHO mutants can transform them to cytidine-independent growth, indicating that the complete structural gene has been isolated. Direct sequencing and enzymatic amplification of the cloned genomic fragments revealed that the coding sequences are distributed to 19 exons covering about 35 kb. Multiple transcriptional start sites were detected by primer extension in a G + C-rich 5' flanking sequence that is separated from the translational start by an approximately 3-kb intron. A panel of human-rodent somatic cell hybrids and the CTPS cDNA were used to assign the structural gene to the short arm of human chromosome 1. This assignment was further refined through the use of somatic cell hybrids bearing fragments of the short arm of the chromosome, allowing localization to 1p36.11-p31, a region notable for its disruption in many types of tumors.

Karyotypic characterization of a new human embryonal rhabdomyosarcoma cell line

Chromosomal analysis of an advanced recurrent rhabdomyosarcoma of the embryonal type was performed on cell cultures in the 9th passage of in vitro cultivation. This tumor showed a modal karyotype of 54 and was characterized by multiple numerical and structural chromosome abnormalities, all present in high frequencies. Abnormalities observed in 100% of the cells included a der(1) chromosome with a short unidentified insertion between q31 and q32; a der(1) chromosome, arising from insertion at the same breakpoint of a longer segment with a duplicated 1q31 band and translocation of 13q23----qter to 1p36, a deleted tetrasomic 13q23----qter, and a der(4) chromosome showing 1p36----pter translocated to 4p13. Other common abnormalities included trisomy of chromosomes 8, 13, and 9p, deletions of chromosomes 6, 10, 11, and 12, and presence of marker chromosomes. Characterization of the established line at the 38th passage evidenced the persistence of both the modal karyotype and all the numerical and structural abnormalities previously found. The results of this study provide further evidence of the major involvement of alterations in chromosome 1 in the progression of rhabdomyosarcoma.

Evolution of tumor chromosome abnormalities after therapy in a pediatric astrocytoma

Chromosome studies originally performed on a patient with an untreated pontine astrocytoma showed a trisomy for 1q as the sole chromosome aberration. After the patient received radiation and chemotherapy, subsequent study indicated the presence of the original trisomy for 1q, as well as trisomy for chromosomes 2, 3q, and 17, in a tumor that now, histologically, is glioblastoma multiforme. In addition to the numerical aberrations, chromosome rearrangements were observed, involving translocation breakpoints that have been reported as "hot spots" associated with the clastogenetic effect of ionizing radiation.

Acute myelomonocytic leukemia with bone marrow eosinophilia and inv(16)(p13q22),t(1;16)(q32;q22)

A two-year-old girl presenting with de novo acute myelomonocytic leukemia with eosinophilia (French-American-British [FAB] classification, M4Eo) and inv(16)(p13q22), t(1;16)(q32;q22) involving the same chromosome 16 is described. This is the second report of a variant translocation of an inverted chromosome 16 with chromosome 1 at 1q32. However, the segment 1q32----1qter has been exchanged for 16q22----qter and not 16p13----pter, as reported in the previous case. The additional break at 1q32 and the juxtaposition of 1q32----qter onto chromosome 16 could be relevant to the pathogenesis of the disease.