Break points in chromosome #1 abnormalities of 218 human neoplasms

Spontaneous chromosome fragility in chorionic villus cells

Human fragile sites are only very rarely expressed spontaneously. In this paper we report the presence of non-random spontaneous chromosome lesions (CL) in chorionic villus samples and their coincidence with fragile site (FS) bands. The average number of CL was about 9% both in RPMI-1640 and in Chang media. To determine any possible influence of external factors other than culture media, the results were grouped according to age of gestation. No differences were observed among the different groups. A total of 101 chromosome lesions could be precisely identified by sequential Leishman Staining/Wright G-banding; 76.2% of them coincided with FS-bands. The most affected region was at 1q12-1q21.1 (15.8% of total CL); other FS with a clustering of breakpoints in our study were 1p36, 1q44, 2q37, 3p24, 3q27, 10q22 and 16q23. These results suggest that spontaneous expression of some FS could be a characteristic of embryonic tissues.

Cytogenetic findings in cervical carcinoma. A statistical approach

Cytogenetic analysis with banding techniques was attempted in 150 cervical carcinomas, including in situ carcinoma, large cell keratinizing tumors, large cell nonkeratinizing tumors, small cell nonkeratinizing tumors, and adenocarcinomas. Monte Carlo simulations were used to determine which numerical and structural aberrations were nonrandomly involved in the tumorous process and to attempt to correlate specific abnormalities with specific histologic types. Results showed that several chromosomes are nonrandomly involved in cervical carcinomas and that some are more specifically associated with particular histologic subtypes. Therefore, cervical carcinoma appear to include a large spectrum of malignancies, each particular histologic type involving different genes. If some cytogenetic changes may be considered general events related to the carcinogenesis process, other rearrangements are presumably more specific processes arising in more committed stem cells.

Trisomy 2 and 20 in two hepatoblastomas

Cytogenetic analysis of two pediatric hepatoblastomas is presented, comparing results in primary tumor samples, nude mouse xenographs, and lung metastases in one case. Both tumors had trisomy 2 and 20 in the primary tumors, along with other structural abnormalities. In subsequent passages/metastases, both tumors showed structural changes in one chromosome 2, resulting in partial trisomy 2q, along with structural changes of other chromosomes. Partial trisomy 1q was also common to both tumors in late stages. Results are compared to those of embryonal rhabdomyosarcoma, where trisomy 2 has also been noted.

1p13 is the most frequently involved band in structural chromosomal rearrangements in human breast cancer

Cytogenetic data on 14 breast carcinomas were examined to determine which chromosome arms and bands are preferentially involved in structural chromosome changes. Chromosome arms 17p, 16q, and 1p and band 1p13 were found to be significantly involved. A review of the world literature confirmed 1p as being the most frequently involved arm in structural chromosome changes in breast cancer and 1p13 as being the band most frequently involved in such changes. The two sets of results were pooled, and the analysis of 113 tumours revealed 229 of 304 bands to be involved, with 1p13 affected in 20% of the tumours.

Chromosome abnormalities involving heterochromatic regions in monocytic leukemia

We report two cases of monocytic leukemia associated with cytogenetic changes involving the juxtacentromeric heterochromatin of different chromosomes. In a patient with chronic myelomonocytic leukemia (CMMoL) we describe a translocation t(1;9)(q12;q13) in which the duplicated derivative chromosome 9q + showed a huge centromeric C-band, derived by fusion of the heterochromatic regions of chromosomes 1 and 9. The constitutional karyotype showed two heterochromatin polymorphisms, 1qh + and inv(9qh). In the second case, an acute monoblastic leukemia was associated with an abnormally elongated juxtacentromeric heterochromatic region of chromosome 4 that was not constitutionally present.

Leukemia characterized by multiple sub-clones with unbalanced translocations involving different telomeric segments: case report and review of the literature

A 68-year-old man presented with t(4;11)(q21;q23), B-lineage acute lymphoblastic leukemia (ALL) which was negative for C-ALL antigen and TdT. Clonal evolution to five different, but related karyotypes, in which chromosomal material distal either to 1q11 or 1q21 was translocated to the terminal regions of 4q-, 11q, 16q, and 19p resulted in partial or total trisomy of 1q. The patient, having achieved a short remission, died 14 weeks after diagnosis. Five reports of jumping translocations in hematological malignancies, four with B-lineage malignancy, are reviewed. One (four cases) or both (one case) of the same 1q breakpoints were consistently found and 11q and 16q were repeatedly involved. Such cases, having multiple subclones with trisomy 1q, may form a distinct subgroup of ALL.

Involvement of 9p in metastatic ovarian adenocarcinomas

By a direct method and after in vitro culture, we cytogenetically analyzed five ovarian adenocarcinomas, using six samples of ascitic fluid. The structural aberrations included rearrangements of chromosomes 1 and 3, in agreement with the results of other researchers. The long arm of chromosome 6 was rearranged in three samples, but no translocation t(6;14) was found. Rearrangements involving 9p were present in all cases, with breakpoints at p13 or p22-23.

Cytogenetic study on acute lymphoblastic leukemia

During 1987-1988 cytogenetic studies were performed in 30 patients with acute lymphoblastic leukemia (ALL). Of the 30 patients 15 (10 children and 5 adults) were found to have abnormal karyotypes including 8 cases (27%) of pseudodiploidy, 2 cases (7%) of hypodiploidy, one case (3%) of low-hyperdiploidy (modal number 47-50), and 4 cases (13%) of high-hyperdiploidy (modal number greater than 50). Immunological classification was performed by using monoclonal antibodies in 26 patients, and the most common immunophenotype was C-ALL. The patients with abnormal karyotypes were more likely to be NuLL-ALL (6 in 14) as compared with patients with normal karyotype (1 in 12). In our series, there was no significant difference between the patients with and without cytogenetic changes in regard of clinical findings such as FAB classification, the rate of complete remission, percentage of lymphoblasts in bone marrow cells and blood picture.

Chromosome aberrations in metastatic ovarian cancer: relationship with abnormalities in primary tumors

Twenty malignant effusions secondary to ovarian cancer have been cytogenetically analyzed directly and after short in vitro culture. With the exception of one sample characterized by trisomy 3, all cases displayed clonal structural rearrangements. Chromosomes 1 and 3 were most frequently involved in the genesis of markers. Abnormalities of chromosomes 5, 6, 9, 11 and 12 were also recurrently found, and double minutes (DM) were observed in 2 samples. Our results agree with previous findings on the preferential involvement of chromosomes 1, 3 and 6 in ovarian carcinomas, and suggest that rearrangements of certain chromosomes are non-random but are secondary to the malignant progression of these tumors.

Abnormalities of chromosome 1 in relation to human malignant diseases

Chromosome 1 is known to often be involved in various malignant diseases. Its numerical and structural aberrations have been observed in chronic and acute leukemias and solid tumors as well. Recently five protooncogenes have been assigned to the long and short arms of chromosome 1. The frequent and nonspecific occurrence of chromosome 1 rearrangements in human tumors suggests that they play an important role in the pathogenesis and progression of these diseases. The frequency, types, and time of the occurrence of chromosome 1 aberrations and their relation to the stage of the disease were studied in 317 patients with various malignant diseases. In ten patients nonrandom aberrations of chromosome 1 were observed. Two patients had CML, two PRV followed by ANLL, and the remaining six patients suffered from ANLL, ALL, Burkitt lymphoma, MF, SMMoL, and IRSA, respectively. In six patients, total or partial trisomy of the long arm or of the whole chromosome 1 was present, and in three cases balanced translocations involving chromosome 1 could be found. In the cells of one patient a duplication of the centromeric heterochromatin was seen. We analyzed the breakpoints involved. Finally, the aberrations of chromosome 1 were almost always be observed at the terminal stage of the diseases.

High incidence of chromosomal lesions involving C-heterochromatin in four human melanoma lines

Cytogenetic analysis of early in vitro cultures derived from human melanomas, two primary tumors (Me 10538, Me 1402) and two metastatic lesions in the same patient (Me 665/1, Me 665/2) showed non-random involvement of C-heterochromatin in clonal chromosome rearrangements. Marker chromosomes with C- and DA-Dapi-positive bands were identified in one of the metastases, Me 665/1 (m1) and in the two primary tumors, Me 10538 (m2) and Me 1402 (m3). C-positive fragments predominated in the other metastasis, Me 665/2, which lacked C-regions intercalated in rearranged chromosomes, and were also detected with appreciable frequency in the Me 665/1 and Me 1402 cells. The frequencies of marker chromosomes and their mean number per cell allowed m2 and m1 to be considered as early markers of tumor formation and m3 as a marker of tumor progression. Dissection of chromosome structure, including the origin of the intercalated C-band, has so far been achieved only with the m2 chromosome of the primary tumor Me10538. This was the only cell line which displayed few C-fragments and a narrow chromosomal distribution with a well defined mode. A gradient of malignancy could be detected in the four cell lines, by local and disseminated tumor growth in xenotransplanted mice, with the two primary melanomas 10538 and the 1402 cells at the lowest and upper extremes. This gradient closely parallels the increase in cytogenetic heterogeneity and C-heterochromatin lesions from the 10538 to the 1402 cells.

Three possible cytogenetic subgroups of leiomyosarcoma

Cytogenetic analysis was performed on short-term cultured tumor cells from ten patients diagnosed as having leiomyosarcoma. Of these, five tumors from five unrelated patients had clonal chromosome abnormalities. The combined data from this report and previous studies on leiomyosarcomas indicate that at least three subtypes may be identified chromosomally within leiomyosarcomas. One subtype is characterized by a hypodiploid chromosome number ranging from 41 to 43 and a common chromosome pattern of monosomies of chromosomes specific to this subgroup, including partial monosomy of the short arm of chromosome 1 (1p13----pter), monosomy 18, and consistent monosomy 22. In contrast to the previous subtype, for the pathogenesis of which the "tumor suppressor gene" hypothesis may be suggested, another subtype was characterized by a pseudodiploid chromosome number associated with simple reciprocal translocations; so far, these translocations are unique to individual tumors, the pathogenesis of which may involve a translocation-mediated gene deregulation pathway. A third subtype contained tumors with heterogeneous karyotypic findings.

Direct cytogenetic analysis of primary neuroblastoma

In this paper the results of cytogenetic analysis of a metastatic neuroblastoma from a 14-month-old boy are described. Direct cytogenetic analysis was performed on tumor pieces obtained from surgery prior to therapy. Consistent numerical and structural chromosome aberrations were identified. The modal chromosome number was 48, with 9.4% of the cell population being in the near-tetraploid range. In all karyotyped cells, the Y chromosome was missing and additions of chromosomes 7 and 14 were identified. Two rearranged #1 were observed: del(1)(p22 or p31) and t(1;18)(p22 or p31;q11-12), resulting in monosomy of the distal segment of the short arm and trisomy of the long arm. In two cells, single minutes were found; this chromosomal aberration has been previously described in a case of metastatic neuroblastoma.

Chromosomal abnormalities and their correlations with asbestos exposure and survival in patients with mesothelioma

Cytogenetic findings of our 30 previously reported and eight new patients with malignant pleural mesothelioma were summarised and correlated with asbestos fibre burden in lung tissue and survival. Successful cytogenetic analyses were performed on cells obtained from the tumours and/or pleural effusions of 34 of the 38 patients. Clonal chromosomal abnormalities were detected in 25 patients, 19 of them studied before treatment. Nine patients, seven of them studied before treatment, had normal karyotypes and/or non-clonal chromosomal abnormalities. Most of the karyotypic findings in the patients with clonal abnormalities were complex and heterogeneous, and no chromosome aberration specific to mesothelioma could be demonstrated. The following numerical abnormalities in decreasing order of frequency were preferentially present in karyotypic changes: -22, +7, -1, -3, -9, +11 and -14 (-/+ denoting partial or total loss or gain). Translocations and deletions involving a breakpoint at 1p11-p22 were the most frequent structural aberrations. Statistically significant correlations were found between high content of asbestos fibres in lung tissue and partial or total losses of chromosomes 1 and 4, and a breakpoint at 1p11-p22 (P = 0.0001, P = 0.003, P = 0.009, respectively). The number of copies of chromosome 7 short arms was inversely correlated with survival (P = 0.02). In this study no diagnostic cytogenetic markers of mesothelioma were found, instead the copy number of chromosome 7 short arms turned out to be a possible prognostic factor in malignant mesothelioma.

Cytogenetic and molecular studies in primary myelofibrosis

Cytogenetic and molecular data of three patients affected by primary myelofibrosis with myeloid metaplasia (PMMM) evolving to blastic crisis are reported. The cytogenetic findings were uncommon. The first patient (female) showed an idic(X)(q13) as the sole alteration in chronic phase, with an additional r(7) in 67% of the cells of the blast crisis; the other two patients showed, in blast crisis, a partial trisomy of the long arm of chromosome 1, without translocation, as a unique structural abnormality. These findings confirm the presence of nonrandom, although nonspecific, alterations in PMMM that, in our cases, seem to be related to the multistep progression of the neoplastic process. Molecular investigations have been applied to study the genomic organization and the level of expression of genes such as bcr and calcyclin and c-fms protooncogene possibly involved in the molecular mechanisms underlying cell proliferation in hematopoietic cells. The data obtained are discussed with respect to the myeloproliferative disorder.

Detection of 1q polysomy in interphase nuclei of human solid tumors with a biotinylated probe

A biotinylated probe (L23-21) specific for the 1q12 band of human karyotype was used to detect the 1q segment in interphase nuclei of breast and colon carcinomas. This probe was selected because trisomy or polysomy 1q is the most frequent chromosomal change observed in solid tumors. This method enables cancerous cells, including near-diploid ones carrying an unbalanced rearrangement of 1q, to be easily identified.

Chromosome 1 abnormalities in cervical carcinoma

Abnormalities of chromosome 1 have been reported in a number of solid tumors and hematologic malignancies, indicating that this is a frequent event in neoplasia. Here we report our observations on aberrations of chromosome 1 in malignancies of the uterine cervix. Tumor material obtained from 148 patients with invasive carcinoma of the cervix and two cases of carcinoma in situ (CIS) was analyzed on direct preparations by G-banding. The results showed abnormalities of chromosome 1 to be one of the most common karyotypic changes, with 95% of the patients showing rearrangements of this chromosome. These changes were never seen as the sole abnormality but were always found in association with other chromosomal aberrations. Numerical rearrangements were present in 54% of the cases, with losses of unaltered chromosome 1 predominating. Consistent marker chromosomes included deletions of chromosome 1 at bands q32, p34, q42, p32, and p22, isochromosomes of both the "p" and "q" arms and translocations, particularly on the long arm. Specific regions on both arms of chromosome 1 (1p11-p13 and 1q21-q32) were preferentially overrepresented in changes involving this chromosome. Certain breakpoints were nonrandomly involved in the structural changes, particularly band 1q32 breaks occurring at this site in 88 instances. The presence of chromosome 1 aberrations in the two cases of CIS suggests that rearrangements of this chromosome are not always a secondary change contributing to the progression of the cancer, but also may represent an early cytogenetic event as in neuroblastoma, some leukemias, and myeloproliferative disorders.

Cytogenetic changes in Wilms' tumors

Cytogenetic analysis of 20 Wilms' tumors using short-term culture techniques were undertaken. Chromosome abnormalities were detected in all tumors. In 19 of 20 cases only minor karyotypic changes were observed within cells with near-diploid chromosome numbers; only one tumor was predominantly hyperdiploid. Rearrangements involving chromosome 1 were the most frequently observed abnormality (in 25%) and often resulted in partial or complete trisomy for the long arm. In 20% of the tumors, abnormalities involving chromosomes 11 and 16 were present. The only other chromosomes frequently involved in structural or numerical changes were #12, and #18. Two discrete tumor foci within the same kidney differed cytogenetically, suggesting an independent origin for each focus. No correlation could be made between specific chromosome abnormalities and tumor stage or histologic subtype. Although constitutional deletion of chromosome region 11p13 has frequently been reported to predispose to Wilms' tumor formation, only two tumors with deletions involving this region were observed. Chromosomes from tumors treated with chemotherapy prior to surgical removal and culture yielded findings similar to those in untreated tumor cells.

Chromosomal involvement secondary to -22 in human meningiomas

Cytogenetic analyses have been performed on cultures in vitro from 32 human meningiomas, seeking chromosomal anomalies in addition to characteristic monosomy 22. Eight cases showed stem lines with normal karyotype, whereas, monosomy 22 as the only chromosomal deviation characterized the stem line of ten tumors. In 14 samples stem lines or modal numbers displaying numerical deviations (other than -22) and/or structural rearrangements were found. A hyperdiploid modal number was present in three, whereas, it was hypodiploid in the remainder. Numerical deviations in these tumors involved mainly #14 by losses, and also #22; recurrent structural rearrangements involving 1p and 11p were also characteristic features. Thus, these results could imply that involvement of #14, 1p, and 11p would be a form of clonal evolution secondary to monosomy 22 in certain meningiomas.

Complex translocation involving chromosomes #1, #9, and #22 in a patient with chronic myelogenous leukemia

A case of Philadelphia chromosome positive chronic myelogenous leukemia with a complex translocation involving chromosomes #1, #9, and #22 is described. All cells in the bone marrow showed this rearrangement, and Q-banding analysis showed the predominant karyotype to be 46,XY, t(1;9;22)(p22;q34;q11).

Tubulovillous adenoma of the colon with hyperdiploidy, double-minute chromosomes, and inversion of chromosome 1

A sessile adenoma of the left flexure of the colon was studied after surgical colectomy. Specimens were obtained for complete histologic evaluation. The tumor consisted of glandular tubes with decreased mucin production and a papillary structure on the luminal aspect. The muscularis mucosa was not involved; there was no carcinomatous focus. Cytogenetic study was carried out on 56 cells; none was normal, 77% were hyperdiploid (52-87 chromosomes), 16% were hypodiploid (18-39 chromosomes), and 7% were paradiploid. The supernumerary chromosomes were chromosomes #3, #6, #13, #19, and #20; chromosome #18 was missing in 80% of the cells. A marker for chromosome #1 resulting from a q21.1-q21.2 break with inversion of the centromere-bearing segment (pter-q21) was observed in 58% of the cells. Twenty-five percent of the cells had double minute chromosomes. Despite the histologically benign nature of the tumor, all the cells showed significant cytogenetic aberrations, some of which are considered to be markers of neoplastic transformation (polyploidy, double minutes, chromosome #1 marker).

Characterization of a T-lymphocyte Epstein-Barr virus/C3d receptor (CD21)

The Epstein-Barr virus/C3d receptor (EBVR-CR2) was detected on three T-lymphoblastoid cell lines. The apparent Mrs of purified EBVR-CR2 of T-cell and B-cell origin were identical. The N-terminal amino acid sequence from the T-cell EBVR-CR2 confirmed the placement of this receptor in a multigene family of complement regulatory proteins. All EBVR-CR2-positive T-cell lines were T6 and T4-T8 antigen positive.

Trisomy of the long arm of chromosome 1 in patients with hematologic malignancies and solid tumors: report of six cases

Complete or partial trisomy of the long arm of chromosome #1 was observed in six patients with malignant disorders. Four patients suffered from hematologic diseases (two cases of refractory anemia with excess of blasts and one case each of acute myeloblastic leukemia and Burkitt lymphoma), and two had solid tumors (retinoblastoma and Ewing's sarcoma). In all cases the excess material included the distal part of chromosome #1. Such material was translocated to chromosomes #16 (three patients), #3, #9, and Y (one patient each), and this was accompanied by additional cytogenetic changes in five of the six patients. The present and other previously published observations support the hypothesis of the localization of genes responsible for malignant growth in the distal segments of chromosome #1.

Stability of cytogenetic alterations in a human melanoma cell line and five clonal derivatives

A cytogenetic study was done on a human malignant melanoma cell line and its 5 clones. Chromosome banding analysis indicated the presence of 7 "shared" markers (M) and 9 unique markers (m) that were present only in the clones. Chromosomes 1, 5, 9, 12, 17 and 21 were involved in M-markers and chromosomes 1, 2, 4, 6, 8, 9, 11, 16, 17, 18 and 21 were involved in m-marker formation. Both parental and clonal lines had near-triploid chromosome numbers. A number of M-markers were isochromosomes of the short (p) and long (q) arms of chromosome 1. Our cytogenetic data indicate that the parental line contained subpopulations of cells that were in different stages of karyotypic evolution.

Chromosome changes in metastatic human melanoma

Cytogenetic studies were performed on human malignant melanoma cells from eight metastatic lesions. Five tumors displayed near-triploid and three near-diploid chromosome numbers. Chromosomes #1, #6, #7, followed by #2 and #9, were found to be most frequently involved in structural aberrations. Aberrations involving chromosome #1, with deletions or translocations of 1p, involving region 1p12-1p22 in seven of eight breakpoints of the p arm were observed. Seven of nine breakpoints of 6q were located at region 6q15-6q21. Most of the breakpoints on chromosome #7 occurred near the centromeric region. All tumors had additional chromosome material involving 1q, chromosome #7 (7q in two tumors), and in five tumors an increased dose of chromosome #6 (6p in one tumor). The nonrandom breakpoints of these and other chromosomes involved diverse bands, including loci of oncogenes and fragile sites. The observation of nonrandom chromosomal changes in advanced malignant melanoma suggests that genes important in the progression of melanoma are located on chromosomes #1, #6, and #7.

Chromosomal patterns in human malignant astrocytomas

Cytogenetic analysis by direct and/or in vitro preparations was performed on 34 malignant astrocytomas. Thirty tumors showed near-diploid chromosome numbers, whereas, tritetraploid chromosome complements were present in four tumors. The most frequent chromosomal changes implied numerical deviations by a gain of chromosomes #7, #19, and #20, and by losses of #10, #22, and Y. Structural rearrangements were present in stem- or side lines of 24 tumors. Although no common chromosomal rearrangement seems to exist among those tumors, chromosomes #1, #6, #7, and #9 were predominantly involved. Polysomy and structural rearrangements of chromosome #7 could be related to the overexpression of epidermal growth factor gene, previously observed in some malignant gliomas.

Cytogenetic findings in two cases of carcinoma in situ of the cervix uterus

Karyotypic analysis of two cases of carcinoma in situ of the cervix uterus, studied on direct preparations by G-banding, revealed numerical and structural abnormalities characteristic of invasive cancers. Abnormalities of chromosome No. 1 were present in both cases. The chromosome No. 1 changes involved isochromosome formation of the long arm (i(1q)) in one case and monosomy in the other. The other chromosomes showing structural aberrations were Nos. 8, 11, and 21. One case revealed the presence of double minute chromatin bodies. The prognosis in both cases was good following excision of the tumor.

Loss of heterozygosity in hypotriploid cell cultures from testicular tumours

We have established cell lines with a hypotriploid chromosome number from four testicular tumours. Each line had at least one Y chromosome and most of the informative centrosome and enzyme markers were heterozygous implying that the tumours originated from germ cells before the first meiotic division. The small metacentric marker chromosome (i12p), specific for testicular tumours, was present in all tumour cell lines and up to three copies were found in some lines. Rearrangements of chromosome 1 and 11 were each found in three out of four tumours. The rearrangements of chromosome 1 all resulted in duplication of 1q and deletion of short-arm material from the same chromosome giving loss of heterozygosity for enzyme markers on 1p. Loss of satellite material from chromosome 13 and the centromere region of chromosome 9 were found in single cases. This study shows that even where the chromosome number of tumour cells is near triploid, regions of the genome can be deleted. The chromosomes most frequently involved in rearrangements, 1, 11, and 12 all contain sites of ras oncogenes and it is suggested that loss of normal alleles could result in homozygosity for mutant oncogenes which may play a part in tumour progression.

Expression of a possible constitutional "hot spot" in sperm chromosomes of a patient treated for Wilms' tumor

Sperm chromosomes were studied in a man who was treated for Wilms' tumor with radiotherapy (RT) and chemotherapy (CT) 18 years ago. Human pronuclear sperm chromosomes were obtained after penetration of zona-free hamster eggs. Eighty-nine sperm chromosome complements were analyzed; 12.4% of them showed structural anomalies. This percentage was statistically different from the one found in our laboratory for controls (p less than 0.05). Five of eleven structurally abnormal metaphases had the same aberration: fission of chromosome #1 with the breakpoint at or near the centromere. Breaks and rearrangements of chromosome #1, often involving the centromere region, are among the most frequent anomalies found in Wilms' tumor cells.

Mosaicism in the C-banded region of chromosome 1 in cancer families

Chromosome 1 C-band length mosaicism was detected in lymphocytes from six tumor patients and one healthy subject belonging to three families with a high incidence of cancer. In all cases the variant cell population showed a decreased amount of C-heterochromatin in one chromosome, whereas the C-banded pattern of the homolog was identical to that of the nonvariant cell population. A family tendency to unequal mitotic crossing over, possibly leading to C-band heteromorphism, may explain the high frequency of detection of C-heterochromatin mosaicism in cancer family members (seven of 13 cases studied). The possible role of heterochromatin in inducing cancer has been widely discussed. The special feature of the acquired C-band variants vis-à-vis the inherited ones is that they mark intrinsic genetic instability that may result, through multiple mechanisms, in increased susceptibility to malignancy.

Single chromosome defect, partial trisomy 1q, in a colon cancer cell line

The characterization of a single chromosome defect previously reported in a case of inherited nonpolyposis colorectal cancer is the essence of this communication. The defect, originally described as 13p+, is now being defined and the karyotype designated as 46,XY,-13,+der(13)t(1;13)(q32.1;p11).

Chromosome findings in multiple myeloma

Cytogenetic studies were performed on six patients with multiple myeloma in which G-banding allowed the identification of clonal chromosome abnormalities. Normal cells and random chromosome gains and losses were seen in all cases. Numerical clonal aberrations were observed in two cases. Among the remaining cases, clonal chromosome rearrangements were seen in two cases, whereas, the other two patients revealed both numerical and structural clonal anomalies. The following marker chromosomes were identified: 1q-, 2p+, 2q+, 7q-, 17p-, and five unidentified abnormal chromosomes.

Marker chromosome 1q+ in acute lymphocytic leukemia

This paper presents the results of a cytogenetic analysis on a patient with acute lymphocytic leukemia (ALL) type L2 according to the FAB classification. Of the metaphases examined, 69.3% belong to the aberrant clone of pseudodiploid karyotype. Marker chromosome 14q+ has been identified in all the cells of the clone. Duplication was found in 30% of the metaphases, and in 15% triplication of the proximal segment of the long arm of chromosome #1 (q11-q21). In one metaphase the long arm of chromosome #1 is made up of segment q11-q21 four times repeated. Aberrations of chromosome #1 support the idea that heterochromatic region may be related to the higher degree of the cell malignity.

Complexity of an apparently simple variant Ph translocation in chronic myeloid leukemia

A patient with chronic myeloid leukemia (CML) presented with an apparently simple Ph translocation t(19;22)(q13;q11). In-situ hybridization revealed movement of the c-abl oncogene from a cytogenetically normal chromosome 9 to the Ph. Bcr-3' and c-sis probes hybridized to distal 1p and not to the 19q+ chromosome as expected from the cytogenetic findings. We concluded that this patient had a complex translocation involving four chromosomes: t(1;9;19;22)(p36;q34;q13;q11).

Multiple telomeric associations of a trisomic whole q arm of chromosome 1 in a child with acute lymphoblastic leukemia

The results of cytogenetic analysis of bone marrow cells from a 13-year-old boy with acute lymphoblastic leukemia (ALL) are described. Initial analysis of aspirated bone marrow disclosed ALL FAB-L1 morphology, common (Ia+, cALLa+) immunophenotype and a complex abnormal karyotype. The majority of leukemic cells showed unbalanced translocations that resulted in complete trisomy of the long arm of chromosome #1 as the common denominator. The heterochromatic region of chromosome #1 (1qh) was associated with the telomeres of whole chromosomes #2, #13, and #16 in 28% of the 36 metaphases completely analyzed. Telomeric association is a very rare event and this is only the second known report of its occurrence associated with ALL wherein the 1qh region is attached to the telomeres of different chromosomes, resulting in trisomy of the whole 1q arm.

Trisomy and tetrasomy for long arm of chromosome 1 in near-diploid human endometrial adenocarcinomas

Karyotypic analysis by R-banding after short-term culture, carried out on 7 cases of human endometrial adenocarcinoma, showed in 4 of these a trisomy or a tetrasomy for the long arm of chromosome I. In the 4 cases, these imbalances were due to rearrangements involving centromeric or para-centromeric break-points: 46,XX,-16, +der(1q16p) t(1;16)(1p16q;1q16p); 46,XX,-21, +der (1q21q)t(1;21) (1p21p;1q21q); 46,XX, -21, +der(21) t(1;21)(q11;p13); 48, XX, +2, +i(1q). Two other cases showed only a numerical aberration: 47, XX, +10 and 47, XX, +12. In the last case, only cells with apparently normal karyotype were seen. In the 4 cases with an anomaly of chromosome I, two normal I chromosomes coexisted with abnormal elements. This shows that the rearrangement very likely occurred in G2 phase of the cell cycle.

Trisomy 1q in polycythemia vera and its relation to disease transition

Clinical and cytogenetic details of 12 patients with polycythemia vera and complete or partial trisomy of the long arm of chromosome 1 are reported. All patients had trisomy for at least the segments 1q22 to 1qter. The 1q or material from 1q was translocated to another chromosome in eight patients. This was chromosome 9 in four patients, and those cases all had trisomy also for 9p. The trisomy 1q was found at the time of diagnosis in three patients, later during the polycythemic phase in five, and in four patients when they were first examined during a late stage of the disease. Acute leukemia or a myelodysplastic syndrome developed in eight of the 12 patients. Signs of advanced disease, eg, myeloid metaplasia or myelofibrosis, preceded the leukemia in four cases and was noted in one more patient. Trisomy 1q was the most frequent structural chromosome abnormality in patients with polycythemia vera. It is thus one of several nonrandom abnormalities that can appear at any stage of the disease. It seems to occur with higher frequency in patients with myelofibrosis and/or leukemia, but it is not a specific characteristic of these complications.

Constitutive heterochromatin studies in patients with solid tumors

Constitutive heterochromatin of chromosomes 1, 9, and 16 was studied in 101 patients with solid tumors and 85 controls. Lymphocyte cultures were used for performing C-banded chromosome preparations. Two homologous chromosomes were regarded as heteromorphic when there was a 25% difference between their C-band size or when they fell into different classes according to the method of Patil and Lubs (1977). A statistically significant difference between patients and controls was found in chromosome 1 heteromorphism. No statistical difference between patients and controls was found in the heteromorphism of chromosomes 9 and 16. The frequencies with which pericentric inversions of the heterochromatin in chromosomes 1 and 9 occurred in cancer patients were 9.9% and 12.9%, respectively. Patients displaying this type of polymorphism usually showed an increased rate of chromosome associations. The most frequent associations were found between heterochromatic regions of chromosomes 1 and 9 and between the chromosome 9 heterochromatin and D acrocentrics. These results support the hypothesis concerning the involvement of constitutive heterochromatin of chromosome 1 in malignant disease.

Chromosome 1 aberrations in cancer

Evidence for chromosome #1 involvement in structural rearrangements in cancer is reviewed. There have been adequate studies of cancer at most of the common sites, and at all of these, nonrandom chromosome #1 involvement has been demonstrated. In general, a variety of changes is encountered, irrespective of the site; most commonly, however, the changes result in the duplication of long arm material. It seems that these nonrandom changes, which tend to occur at a relatively late stage, may contribute to the progression of all forms of cancer. However, a small number of chromosome #1 aberrations are also now known, which may represent specific and possibly initiating changes in particular forms of cancer. These include short arm deletions in neuroblastoma and translocations in leukemias and myelodysplasia.

Chromosome 1 in relation to human disease

Chromosome 1 is thought to represent about 6% of the total human genome and the 85 loci so far identified may constitute about 1% of the genes present on this chromosome. The existence of at least 22 loci sufficiently polymorphic in Europeans to be useful as genetic markers has allowed the construction of an elementary genetic map. This permits comparisons with physical and chiasma maps and has demonstrated striking homologies between different regions of chromosome 1 and mouse chromosomes 1, 3, and 4. The existence of a map should be of great help in developing a more systematic approach to further mapping studies. A wide range of disease can be attributed to allelic variation on chromosome 1 and the homologies with the mouse may be useful in predicting the position of other genes involved in human disease. Rearrangements of this chromosome are a common finding in many different types of malignancy. Loss of material from the short arm and activation of one or more of the four oncogenes in this region may play an important role in the later stages of tumour development. Polymorphic markers of all kinds will be useful in the future for investigating the somatic events which have occurred during the malignant process.

Cytogenetics of a renal adenocarcinoma in a 2-year-old child

Chromosomal abnormalities in a 2.4-year-old boy with renal adenocarcinoma (Grawitz tumor) are described. Renal adenocarcinoma is extremely rare in childhood, compared with nephroblastoma (Wilms' tumor). In all tumor cells the same 46,XY,t(X;1) (p11.2;q21.2) karyotype was found. This karyotype is compared with the cytogenetic descriptions of renal adenocarcinoma in adults.

An identical translocation between chromosome 1 and 15 in two patients with myelodysplastic syndromes

An identical translocation between the long arm of chromosome no. 1 and the short arm of chromosome no. 15 was found in two unrelated patients with refractory anaemia type I, according to the FAB classification of myelodysplastic syndromes. In the first patient the typical translocation was associated with anomalies commonly found in preleukaemic states, i.e. a 5q- and a 20q- chromosome. Furthermore, in both patients the long arm of chromosome no. 1 was trisomic. Cytogenetic follow-up in the second patient demonstrated a proliferative advantage of the cells bearing a t(1;15) translocation over the cells with trisomy 8 as well as over normal cells. This karyotypic evolution, however, was not accompanied by a transformation of the haematological disorder into acute leukaemia.

RCH-ACV: a lymphoblastic leukemia cell line with chromosome translocation 1;19 and trisomy 8

A cell line (RCH-ACV) was established from a bone marrow sample of a child with acute lymphoblastic leukemia (ALL). The cell line lacked Epstein-Barr virus nuclear antigen and exhibited a recently described nonrandom chromosome translocation, 1;19, thought to be associated with pre-B-ALL and poor prognosis. Banding studies confirm that the breakpoint of chromosome #19 occurs at p13.3. Cell surface marker analysis using a panel of monoclonal antibodies revealed markers consistent with common ALL phenotype. Although the cells did not show cytoplasmic immunoglobulin, studies of the immunoglobulin gene rearrangement confirmed the pre-B phenotype. This cell line could be of great value to studies of the role of the specific translocation 1;19 in the etiology of pre-B-ALL.

Karyotypic evolution in human malignant melanoma

Chromosome studies were performed on direct preparations, early passage cultures, and cell lines derived from melanocytic lesions of 37 patients. There were six congenital or common acquired nevi, six dysplastic nevi, one early primary melanoma (radial growth phase), three complex melanomas (RGP with foci of vertical growth phase), six advanced primary melanomas (VGP), and 26 metastases. The karyotype was normal in the six common nevi. A chromosomally abnormal clone with a single karyotypic alteration was found in two dysplastic nevi. All melanomas had clones with multiple cytogenetic changes. Nonrandom abnormalities involving translocations or deletions in the short arm of chromosome #1, either arm of chromosome #6, and/or extra copies of the short arm of chromosome #7 were present in all melanomas. These were not obviously associated with a particular stage of disease, except that the only nonrandom alteration in the early (RGP) melanoma involved chromosome #6. In four cases, cytogenetic data were available on both a primary melanoma and its metastases. In each instance there were common alterations (demonstrating the clonality of the disease), as well as additional changes in the metastases. Our findings indicate that demonstrable somatic genetic abnormalities increase in severity with clinical progression of melanocytic disease, but additional data are required to establish the significance of specific karyotypic changes (and the involved genes) in the clinical evolution of these disorders.

Cytogenetic and molecular biologic alterations in human breast cancer: a review

Chromosomal and molecular biologic studies of human breast cancer are beginning to provide insight into the basic biology of this important disease. The current state of knowledge of both cytogenetic evaluation and assessment of expression and amplification of cellular oncogenes in breast cancer will be outlined in this brief review.

Isolation and chromosomal localization of the human fgr protooncogene, a distinct member of the tyrosine kinase gene family

The cell-derived domain of Gardner-Rasheed feline sarcoma virus (GR-FeSV) consists of a gamma-actin- and a tyrosine-specific protein kinase-encoding sequence designated v-fgr. By utilizing a v-fgr probe, it was possible to detect related sequences present at low copy number in DNAs of a variety of mammalian species and to isolate a human fgr homologue. Comparative studies revealed that this human DNA clone represented all but 200 base pairs of v-fgr. Analysis of human genomic DNA demonstrated that the fgr protooncogene was distinct from the cellular homologues of other retrovirus onc genes. In addition, the fgr protooncogene was localized to the distal portion of the short arm of human chromosome 1 at p36.1-36.2 by in situ hybridization. Taken together, our findings establish that the fgr protooncogene is a unique member of the tyrosine kinase gene family.

Neuroepithelioma (neuroblastoma) arising in an adult. A case report

Cytogenetic studies on neuroblastomas arising in children have revealed consistent abnormalities of the short arm of chromosome number 1. Partly because of the rare occurrence of neuroblastomas in adults, extensive cytogenetic studies in this group of patients have not been performed. We report a case of a neuroepithelioma (neuroblastoma) arising in a 50-year-old male patient. On chromosome analysis of a metastasis, a stemline with karyotype 47,XY, +der1 (1 qter---1 cen::1q21---1 qter) was identified. The possible consequences of this result and those of results previously reported in the literature are discussed.