Familial osteosarcoma associated with 13;14 chromosomal rearrangement

Two prepubertal sisters of American Indian origin developed osteosarcoma at 8 and 12 years of age. This familial occurrence, tumor onset prior to puberty, unusual tumor location in one who also had short stature, and ethnic background all suggest an inborn predisposition to bone cancer rather than a chance occurrence. Rearrangements involving chromosomes #13 and #14 were found in both the surviving proband and mother. Comparison of the arm ratio and prometaphase G-banding patterns of the rearranged chromosomes suggests either deletion of band 14q11.2 or pericentric inversion (with breakpoints at 13q12 and 14q11.2) in the proband's rearranged chromosome, but not in her mother's. Her mother, who had no malignancy, had a typical Robertsonian translocation [t(13;14)(p11;q11)]. Three previously reported children with chromosomal abnormalities developed osteosarcoma at unusually young ages, younger even than in reported sibships with osteosarcoma. The most frequently detected cytogenetic abnormalities in sarcoma tumor cells involve chromosomes #13 and #14. In addition, some cases of bilateral retinoblastoma and familial unilateral retinoblastoma, which are known to be at increased risk for osteosarcoma, are associated with tiny deletions on chromosome #13. Thus, there may be a causal relationship between constitutional loss or rearrangement of genetic material at these breakpoints on chromosomes #13 or #14 and development of osteosarcoma in this family that is similar to that seen in patients with small constitutional chromosomal deletions who develop Wilms' tumor and retinoblastoma.     

A nonrandom chromosomal abnormality, del 3p(14-23), in human small cell lung cancer (SCLC)

In order to determine whether or not there are specific chromosomal changes in small cell lung cancer (SCLC), karyotypic analyses of 16 continuous SCLC tissue culture lines, three fresh tumor specimens (bone marrow), one direct preparation of bone marrow involved with SCLC, and two lymphoblastoid lines derived from SCLC patients were studied. Cell lines were derived from primary tumor, or metastases to bone marrow, subcutaneous nodules, or pleural fluid; all 16 lines had biochemical and histologic properties characteristic of SCLC. Of the 15 males and 3 females, 6 patients had no prior treatment. All of the 16 cell lines, the 3 fresh specimens, and the direct bone marrow preparation had a common deletion of the short arm of chromosome #3. Use of the shortest region of overlap analysis showed the common deletion was of the short arm in the regions p(14-23). This specific chromosomal abnormality, del 3p, was not found in five non-SCLC cell lines studied and is of major potential biological and diagnostic importance.     

Cytogenetics of human malignant melanoma and premalignant lesions

Chromosome studies were done on direct preparations, early passage cultures, and/or cell lines derived from melanocytic lesions of 17 patients. There were 5 nevi (3 dysplastic); 1 early primary melanoma (radial growth phase); 1 advanced primary melanoma (vertical growth phase) with multiple metastases; and 10 metastatic lesions. The 5 nevi had normal karyotypes, while each of the tumors had a predominantly abnormal karyotype. The early melanoma was pseudodiploid, including a 6p;22 translocation. Ten of the 11 advanced melanomas had one or more aberrations involving chromosome #1, with 9 having deletions or translocations of Ip that involved the proximal segment 1p12→1p22 9 times in 8 lesions. Six advanced tumors had additional material involving 7q, including extra #7s (4 cases) and 7q (2 cases). Nine melanomas, including the early tumor, had alterations in chromosome #6. Three had additional copies of 6p (as iso6p or t6p); the others showed no consistent pattern. In one advanced tumor, the primary lesion and 5 metastases (removed seriatim over an 18-month period) had nearly identical karyotypes, indicating the clonal nature of the neoplasm. The nonrandom cytogenetic changes suggest that genes important in melanoma carcinogenesis are located on the proximal portion of 1p, on 7q, and on chromosome #6. More data on early lesions are needed to identify the relation of these various cytogenetic changes to the different stages of malignant melanoma development.     

Consistent chromosomal losses in head and neck squamous cell carcinoma cell lines

Clonal chromosomal abnormalities were characterized in nine cell lines established from squamous cell carcinomas of the head and neck. Aneuploidy was a common feature; one cell line was near-diploid, three were near-triploid, four were near-tetraploid, and one cell line showed extensive variation in chromosome numbers. Consistent numerical abnormalities included loss of the sex chromosomes in six cell lines, losses of chromosomes 2 and 21 in six and five cell lines, respectively, and gain of chromosome 20 in five cell lines. Recurrent structural rearrangements included del(10)(q22-q26) (seven cell lines), i(5)(p10) (six cell lines), i(8)(q10) (six cell lines), add(19)(q13) (six cell lines), del(4)(q21-q31.3) (five cell lines), i(3)(q10) (four cell lines), del(12)(p11.1-p12) (four cell lines), and add (18)(q21-q23) (four cell lines). Other changes were noted in lower frequencies. Loss of specific regions on chromosomes 2, 3p, 4q, 5q, 8p, 10q, 12p, 18q, 19q, and 21 suggests that they may represent sites of putative tumor suppressor genes, loss of which may play a role in the pathogenesis of squamous cell carcinomas of the head and neck. Alternatively, gain of chromosomal region 3q, 5p, and 8q due to isochromosome formation suggests that more than one mechanism is involved in malignant transformation. Cytogenetic evidence of gene amplification was found in two cell lines; as an hsr(11)(q 13) in one and as dmins in the other. The clonal karyotypes of four cell lines were compared with those of their respective primary tumors. In all cell lines, clonal evolution had occurred, with loss of some rearrangements present in the primary tumors or the gain of additional abnormalities.     

Chromosomal gains and losses in ocular melanoma detected by comparative genomic hybridization in an Australian population-based study

To define the location of potential oncogenes and tumor suppressor genes in ocular melanoma we carried out comparative genomic hybridization (CGH) analysis on a population-based series of 25 formalin-fixed, paraffin-embedded primary tumors comprising 17 choroidal, 2 ciliary body, 4 iris, and 2 conjunctival melanomas. Twelve (48%) of the 25 melanomas showed no chromosomal changes and 13 (52%) had at least one chromosomal gain or loss. The mean number of CGH changes in all tumors was 3.3, with similar mean numbers of chromosomal gains (1.5) and losses (1.8). The highest number of chromosomal changes (i.e., nine) occurred in a conjunctival melanoma and included four changes not observed in tumors at any other ocular site (gains in 22q and 11p and losses in 6p and 17p). The most frequent gains in all primary ocular melanomas were on chromosome arm 8q (69%), 6p (31%) and 8p (23%) and the most frequent losses were on 6q (38%), 10q (23%), and 16q (23%). The most common pairing was gain in 8p and gain in 8q, implying a whole chromosome copy number increase; gains in 8p occurred only in conjunction with gains in 8q. The smallest regions of copy number alteration were mapped to gain of 8q21 and loss of 6q21, 10q21, and 16q22. Sublocalization of these chromosomal changes to single-band resolution should accelerate the identification of genes involved in the genesis of ocular melanoma.     

G-banded karyotype of a primary renal-cell carcinoma

Cytogenetic findings of a primary renal-cell carcinoma are reported. The chromosome number was near triploid and there was tetrasomy for the long arm of chromosomes #1 and #3. The following structural chromosomal abnormalities were identified by the G-banding technique: i(1q), t(3;17), 6q-, 7p+, and a ring chromosome of unknown origin. Chromosomes #1, #3, #6, #7, and #17 involved in this case are often implicated in malignancy.     

Cytogenetic study of a testicular tumor in a translocation (13;14) carrier

We performed chromosomal analysis of a primary testicular tumor from an individual who, on subsequent analysis of peripheral blood, was found to have a balanced (13q14q) translocation. Histologically, the tumor was a mixed germ cell neoplasm, predominantly embryonal carcinoma, with some teratomatous elements. The modal chromosome count of the tumor cells was 62, with most counts ranging from 54 to 66. In addition to a t(13q14q) chromosome (of constitutional origin), nine nonrandomly acquired chromosomal abnormalities were identified, including an abnormal chromosome #1 and a probable i(12p). These findings are further discussed and compared with cytogenetic data on human testicular neoplasms from the literature. This case is also discussed with regard to the possible association of a constitutional t(13q14q) and various malignancies and related disorders.     

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.     

Analysis of ovarian cancer cell lines using array-based comparative genomic hybridization

In this study, 23 ovarian cancer cell lines were screened using array-comparative genomic hybridization (aCGH) based on large-insert clones at about 1 Mb density from throughout the genome. The most frequent recurrent changes at the level of the chromosome arm were loss of chromosome 4 or 4q, loss of 18q and gain of 20 or 20q; other recurrent changes included losses of 6q, 8p, 9p, 11p, 15q, 16q, 17p, and 22q, and gain of 7q. Losses of 4q and 18q occurred together more often than expected. Evidence was found for two types of ovarian cancer, one typically near-triploid and characterized by a generally higher frequency of chromosomal changes (especially losses of 4p, 4q, 13q, 15q, 16p, 16q, 18p and 18q), and the other typically near-diploid/tetraploid and with fewer changes overall, but with relatively high frequencies of 9p loss, 9q gain, and 20p gain. Multiple novel changes (amplifications, homozygous deletions, discrete regions of gain or loss, small overlapping regions of change and frequently changed clones) were also detected, each of which might indicate the locations of oncogenes or tumour suppressor loci. For example, at least two regions of amplification on chromosome 11q13, one including cyclin D1 and the other the candidate oncogene PAK1, were found. Amplification on 11q22 near the progesterone receptor gene and a cluster of matrix metalloproteinase loci was also detected. Other potential oncogenes, which mapped to regions found by this study, included cyclin E and PIK3C2G. Candidate tumour suppressor genes in regions of loss included CDKN2C, SMAD4-interacting protein and RASSF2.     

Chromosomal composition of a series of 22 human low-grade gliomas

G-banded chromosomal analysis was performed on direct and/or in vitro cultures of 22 low-grade gliomas, including nine grade I-II astrocytomas, nine oligodendrogliomas, one mixed tumor oligodendroglioma-astrocytoma, and three ependymomas. Normal diploid stem lines were present in most astrocytomas and oligodendrogliomas, whereas, all three ependymomas displayed polyploid modal numbers. However, secondary cell lines showed the presence of clonal recurrent numerical abnormalities, mainly polysomy 7, monosomy 10 and 22, and loss of the Y chromosome. Clonal structural rearrangements were present with a low incidence; they mainly involved chromosomes #1 and #7. These patterns of chromosome involvement seem to correlate with the scarce previous cytogenetic banding data available from low-grade gliomas. They are also similar to the chromosome alterations found in high-grade gliomas.     

Chromosome changes in a secondary lymphoma

A case of probable secondary lymphoma, poorly differentiated lymphocytic lymphoma (PDLL), is described in which two chromosomal translocations were observed, i.e., t(10;19)(q11;q13) and t(1;6)(q21;p11.1-2). A consistent numerical aberration was monosomy of chromosome #21. Accumulation of more data on secondary lymphomas is necessary in order to reach a general conclusion as to whether or not there are any nonrandom chromosomal aberrations that differentiate primary from secondary lymphomas.     

Genetic characterization of immortalized human prostate epithelial cell cultures. Evidence for structural rearrangements of chromosome 8 and i(8q) chromosome formation in primary tumor-derived cells

We have utilized a combination of conventional and spectral karyotyping (SKY) techniques and allelotype analysis to assess numerical and structural chromosome alterations in two cell lines derived from normal human prostatic epithelium, and three cell lines derived from human prostate primary tumor epithelium, immortalized with the E6 and E7 transforming genes of human papilloma virus (HPV) 16 or the large T-antigen gene of simian virus 40 (SV40). These studies revealed trisomy for chromosome 20 and rearrangements involving chromosomes 3, 4, 8, 9, 10, 16, 17, 18, 19, 21, or 22. In addition, the four HPV-immortalized cell lines exhibited extensive duplications or translocations involving the 11q chromosomal region. Interestingly, allelotyping data disclosed loss of 8p sequences in two of the three primary tumor-derived cell lines, and SKY data revealed that the loss of 8p sequences was directly due to i(8q) chromosome formation and/or other structural alterations of chromosome 8. This provides intriguing evidence that 8p loss in primary human prostate tumors may, in some cases, result from complex structural rearrangements involving chromosome 8. Moreover, the data reported here provide direct evidence that such complex structural rearrangements sometimes include i(8q) chromosome formation.     

Triple-color FISH analysis of 12p amplification in testicular germ-cell tumors using 12p band-specific painting probes

Forty-nine surgical specimens and nine germ cell tumor lines were analyzed by triple-color FISH using microdissected probes for the cytogenetic bands of chromosome arm 12p (12p11.2, p12, and p13). FISH analysis demonstrated amplification of material from all three bands in all tumors. This amplification was in the form of increased copy number of 12p or i(12p) and/or 12p amplified regions (AMP12p). The number of copies of 12p was variable (4–11 copies) from case to case but tended to remain relatively constant in all clones of the same tumor, even when the amplification took the form of an amplified region composed of 12p material. In tumors with multiple clones, i(12p) and AMP12p were never found in the same cell. No correlation was found between 12p copy number and tumor type. We describe, for the first time, a relative overrepresentation of 12p13 or 12p12–p13 regions in six tumors (two surgical samples and four cell lines), either as ”partial 12p” (five cases) or within a 12p amplified region (one case). The ubiquitous amplification of all three 12p bands in germ-cell tumors supports the hypothesis that 12p harbors more than one gene important for oncogenesis of adult male germ-cell tumors, and that these genes may be located in different areas of 12p. Received: 4 March 1998 / Accepted: 12 May 1998     

Chromosomal composition of four permanent cultured cell lines derived from human gliomas

Four permanent cell lines derived from malignant human gliomas were karyotyped using Giemsa-trypsin banding. D-65 MG had a stemline with 44 chromosomes, including 11 markers: 1p+, 2q-, 3p-, 3q+, 4p-, 9q-, 11q+, 15q-, 17p+, 21p+, 22q-. The net effect after accounting for fragments in markers was: +8, -10, -16 -X. D-32 MG had chromosome counts 90-91 without a distinct stem karyotype. Modal cells contained from 3 to 5 copies of the normal autosomes and 5 markers: 1q-, 3q-, 7q-, 13q-, 18q-. D-32 MGCl2 had a complex karyotype containing 78-82 chromosomes. There was no stemline, and modal cells varied from one another primarily in their set of marker chromosomes. A total of 23 markers were seen in this line, 17 of which were present in most modal cells. They were partially characterized as: 1q+, 1q+, 2q-, 5q+, 7p-, 7q-, 8p+, 8p+, 9p+, 12p+, 14q-, 16q+, 19q+, 19q+, a small submetacentric chromosome of undetermined origin and two small isochromosomes, i(Dp or Gp) and i(17p or 18p). A-172 MG had a modal peak of 77 chromosomes within which no two cells were exactly alike. Ten markers seen in modal cells were: 1p-, 4p+, 6p+, 6p+, 6q-, 7p-, 9p-q+, 13q+ 14p+, 22q+. There were no normal copies of chromosomes #1, #6, #9, #14. These four glioma-derived cell lines possess unique karyotypes, but each displays some combination of the numerical and structural deviations generally associated with established glioma lines.     

Molecular cytogenetic analysis of archival uveal melanoma with known clinical outcome

Uveal melanoma (UM) is the most common primary intraocular tumor in the Western world. Cytogenetically, this tumor is characterized by typical chromosomal aberrations such as loss of 1p, 3, and 6q, and gain of 6p and 8q. Routinely, karyotyping and fluorescent in situ hybridization (FISH) on fresh tumor-biopsies are used to identify chromosomal changes. In addition, archival UM samples can be examined using comparative genomic hybridization (CGH). In the presented study, we used CGH on a series of 46 archival uveal melanomas to identify chromosomal changes. In 44 tumors aberrations were present and classic prognostic markers as loss of 1p (12 tumors, 26.1%), monosomy 3 (26 tumors, 56.5%), loss of 6q (10 tumors, 21.7%), and gain of chromosome arm 8q (27 tumors, 58.7%) were observed. Gain of chromosome arms 18q or 21q was found in three UMs. Multiplex ligation-dependent probe amplification (MLPA), a novel technique in UM, was performed to verify this low number of chromosome 18 and 21 abnormalities, but we could not confirm the previously reported gain of 18q11.2 and 21q11.2 as poor prognostic factors in UM.     

大肠癌的细胞遗传学研究

目的研究大肠癌的发生机理,期望发现与大肠癌发生有关的染色体脆性位点,以指导大肠癌高危人群的筛查和防治。方法对２０例大肠癌手术切除瘤组织及４例大肠癌细胞系进行了细胞遗传学研究。结果发现癌细胞多为异倍体,染色体数目以亚二倍体居多,常见１３号染色体增多及１７、１号染色体丢失;结构畸变较常累及１号染色体,以１ｑ２１,１ｐ１３区的裂隙、断裂、末端丢失最为常见。对比大肠癌细胞染色体高度非随机断裂点与脆性位点和目前所确认的癌基因位点,发现三者同位或毗邻的位点为１ｑ２１。结论１ｑ２１可能与大肠癌的发生有关,并对大肠癌高危人群的筛查和防治有一定的指导意义。     

20例原发性肝癌实体瘤的细胞遗传学研究

本研究采用直接法制备和分析了２０例原发性肝癌实体瘤Ｇ带染色体，每例实体瘤都有明显的染色体数目和结构异常。常见出现结构异常的染色体有１、２、３、７、和１１，９０％（１８例）的实体瘤有１号染色体长短臂不同程度的缺失和重排，２号染色体异常在８０％的实体瘤出现，尤以２ｐ－为突出。本研究所见提示各种染色体的缺失和重排特别是１号染色体的改变、２号和７号染色体短臂的缺失，可能是引起多个原癌基因的激活和抑癌基因失活的基础。     

Chromosome analysis of three seminomas

Each of three seminomas revealed chromosome #1 and #12 structural changes in direct preparations and short-term cultures. The #1 changes involved duplication of 1q and loss of 1p; in two, the breakpoint was in the heterochromatic region. The anomaly in #12 was a short arm isochromosome, usually present in duplicate. In one tumor, these were the only structural changes; in the other two, there was also involvement of #7, with extra copies of 7p. In one of these two tumors, a heterochromatic minute was identified after C-banding, and in the other, aside from two different markers containing part of #7, there was a dicentric derived from two chromosomes #15; this tumor proved to be prognostically unfavorable. Three normal chromosomes #1 and XXY sex chromosomes were present in each tumor. Chromosomes #11 and #13 were generally underrepresented, and #12 and #19-22 were over-represented.     

Nonrandom pattern of cytogenetic abnormalities in squamous cell carcinoma of the larynx

Cytogenetic analysis of short-term cultures from 105 squamous cell carcinomas of the larynx (LSCC) revealed clonal chromosome aberrations in 56 tumors. Simple karyotypic changes (less than four aberrations per clone) were found in 24 cases, and the remaining 32 tumors had complex karyotypes with multiple numerical as well as unbalanced structural rearrangements. Extensive intratumor heterogeneity, in the form of multiple related subclones or unrelated clones, was observed in a large fraction of the tumors. The structural changes most often affected chromosomes 3, 1, 11, 7, 2, 15, 5, 4, 8, and 12, with rearrangements in the centromeric regions, i.e., the centromeric bands p10 and q10 and the juxtacentromeric bands p11 and q11, accounting for 43% of the total breakpoints. The most common imbalances brought about by numerical and unbalanced structural rearrangements were loss of chromosomal region 3p21-pter, chromosome arms 4p, 6q, 8p, 10p, 13p, 14p, 15p, and 17p, and gain of chromosomal regions 3q21-qter, 7q31-pter, and 8q. Among 17 recurrent aberrations identified, the most common were i(8q), hsr(11)(q13), i(3q), i(5p), and del(3)(p11). No statistically significant association was found between major karyotypic features and histological differentiation or TNM stage. The karyotypic features of the LSCC were also compared with previously published oral SCC, a subgroup of SCC that has been more extensively characterized cytogenetically. No clear-cut karyotypic differences were found between LSCC and oral SCC, with the exception that i(8q) was significantly more frequent among the latter.     

A possible specific chromosome change in transitional cell carcinoma of the bladder

Chromosome changes were ascertained in nine tumor samples from seven untreated patients with transitional cell carcinoma of the urinary bladder. All tumors analyzed showed abnormal karyotypes. In one tumor, a single numerical abnormality (+7) was the sole detectable change. From 1 to 19 structurally abnormal chromosomes could be identified in the remaining 8 tumors. The same abnormality, an isochromosome of the short arm of chromosome #5, was found in five tumors from four patients. We have previously described the presence of this marker chromosome in three of nine cases of transitional cell carcinoma of the bladder. We therefore conclude that i(5p) constitutes the most consistent nonrandom chromosome abnormality in this malignancy. Other chromosomes most frequently involved in structural changes in the present series of tumors were chromosomes #1, #6, #11, and #13.