AIB1, a steroid receptor coactivator amplified in breast and ovarian cancer

Members of the recently recognized SRC-1 family of transcriptional coactivators interact with steroid hormone receptors to enhance ligand-dependent transcription. AIB1, a member of the SRC-1 family, was cloned during a search on the long arm of chromosome 20 for genes whose expression and copy number were elevated in human breast cancers. AIB1 amplification and overexpression were observed in four of five estrogen receptor-positive breast and ovarian cancer cell lines. Subsequent evaluation of 105 unselected specimens of primary breast cancer found AIB1 amplification in approximately 10 percent and high expression in 64 percent of the primary tumors analyzed. AIB1 protein interacted with estrogen receptors in a ligand-dependent fashion, and transfection of AIB1 resulted in enhancement of estrogen-dependent transcription. These observations identify AIB1 as a nuclear receptor coactivator whose altered expression may contribute to development of steroid-dependent cancers.

A targeted disruption of the murine Brca1 gene causes gamma-irradiation hypersensitivity and genetic instability

Germline mutations of the Brcal gene are responsible for most cases of familial breast and ovarian cancers, but somatic mutations are rarely detected in sporadic events. Moreover, mouse embryos deficient for Brca1 have been shown to die during early embryogenesis due to a proliferation defect. These findings seem incompatible with the tumor suppress function assigned to this gene and raise questions about the mechanism by which Brca1 mutations cause tumorigenesis. We now directly demonstrate that BRCA1 is responsible for the integrity of the genome. Murine embryos carrying a Brca1 null mutation are developmentally retarded and hypersensitive to gamma-irradiation, suggesting a failure in DNA damage repair. This notion is supported by spectral karyotyping (SKY) of metaphase chromosomes, which display numerical and structural aberrations. However, massive chromosomal abnormalities are only observed when a p53-/- background is introduced. Thus, a p53 dependent cell cycle checkpoint arrests the mutant embryos and prevents the accumulation of damaged DNA. Brca1-/- fibroblasts are not viable, nor are Brca1-/-:p53-/- fibroblasts. However, proliferative foci arise from Brca1-/-: p53-/- cells, probably due to additional mutations that are a consequence of the accumulating DNA damage. We believe that the increased incidence of such additional mutations accounts for the mechanism of tumorigenesis associated with Brca1 mutations in humans.

Rapid generation of region specific probes by chromosome microdissection and their application

The strategy presented here to identify unequivocally cryptic chromosomal rearrangements has relevance to both prenatal and postnatal cytogenetic analysis as well as the analysis of tumour-associated chromosome rearrangements. Microdissection and in vitro amplification of specific chromosomal regions are performed, followed by labelling for fluorescent in situ hybridization (FISH) to normal metaphase chromosomes (Micro-FISH). Micro-FISH probes have been used successfully to determine the derivation of chromosome segments unidentifiable by standard chromosome banding analysis. Micro-FISH probes (created in less than 24 hours) now make it possible to identify explicitly the chromosome constitution of virtually all cytologically visible chromosome rearrangements.

A nuclear factor, ASC-2, as a cancer-amplified transcriptional coactivator essential for ligand-dependent transactivation by nuclear receptors in vivo

Many transcription coactivators interact with nuclear receptors in a ligand- and C-terminal transactivation function (AF2)-dependent manner. We isolated a nuclear factor (designated ASC-2) with such properties by using the ligand-binding domain of retinoid X receptor as a bait in a yeast two-hybrid screening. ASC-2 also interacted with other nuclear receptors, including retinoic acid receptor, thyroid hormone receptor, estrogen receptor alpha, and glucocorticoid receptor, basal factors TFIIA and TBP, and transcription integrators CBP/p300 and SRC-1. In transient cotransfections, ASC-2, either alone or in conjunction with CBP/p300 and SRC-1, stimulated ligand-dependent transactivation by wild type nuclear receptors but not mutant receptors lacking the AF2 domain. Consistent with an idea that ASC-2 is essential for the nuclear receptor function in vivo, microinjection of anti-ASC-2 antibody abrogated the ligand-dependent transactivation of retinoic acid receptor, and this repression was fully relieved by coinjection of ASC-2-expression vector. Surprisingly, ASC-2 was identical to a gene previously identified during a search for genes amplified and overexpressed in breast and other human cancers. From these results, we concluded that ASC-2 is a bona fide transcription coactivator molecule of nuclear receptors, and its altered expression may contribute to the development of cancers.

Telomere capture stabilizes chromosome breakage

Terminal deletions are found frequently in both malignancies and clinically recognizable deletion syndromes in man. Little is known, particularly in cancer, of the specific mechanisms which lead to the generation of deleted chromosomes or the process by which these broken chromosomes are stabilized. We demonstrate that several examples of apparent terminal deletions are, in fact, subtelomeric translocations which were not detectable using conventional cytogenetics. The unexpectedly high frequency of this phenomenon and the diversity of partner chromosomes involved in the subtelomeric translocations is consistent with a model in which telomere capture can stabilize chromosome breakage in man.

MicroRNA-377 suppresses initiation and progression of esophageal cancer by inhibiting CD133 and VEGF

Esophageal cancer is one of the most lethal cancers worldwide with poor survival and limited therapeutic options. The discovery of microRNAs created a new milestone in cancer research. miR-377 is located in chromosome region 14q32, which is frequently deleted in esophageal squamous cell carcinoma (ESCC), but the biological functions, clinical significance and therapeutic implication of miR-377 in ESCC are largely unknown. In this study, we found that miR-377 expression was significantly downregulated in tumor tissue and serum of patients with ESCC. Both tumor tissue and serum miR-377 expression levels were positively correlated with patient survival. Higher serum miR-377 expression was inversely associated with pathologic tumor stage, distant metastasis, residual tumor status and chemoradiotherapy resistance. The roles of miR-377 in suppressing tumor initiation and progression, and the underlying molecular mechanisms were investigated. Results of in vitro and in vivo experiments showed that miR-377 overexpression inhibited the initiation, growth and angiogenesis of ESCC tumors as well as metastatic colonization of ESCC cells, whereas silencing of miR-377 had opposite effects. Mechanistically, miR-377 regulated CD133 and VEGF by directly binding to their 3' untranslated region. Moreover, systemic delivery of formulated miR-377 mimic not only suppressed tumor growth in nude mice but also blocked tumor angiogenesis and metastasis of ESCC cells to the lungs without overt toxicity to mice. Collectively, our study established that miR-377 plays a functional and significant role in suppressing tumor initiation and progression, and may represent a promising non-invasive diagnostic and prognostic biomarker and therapeutic strategy for patients with ESCC.

Identification of cryptic sites of DNA sequence amplification in human breast cancer by chromosome microdissection

We have performed microdissection of 16 putative homogeneously staining regions (hsrs) from nine different breast cancer cell lines in order to determine their chromosomal origin and composition. As expected, the most commonly amplified chromosomal band-region was 17q12 (containing ERBB2). However, regions not containing known oncogenes were also identified, including 13q31 (5/9 cases) and 20q12-13.2 (4/9 cases). The chromosomal composition of the integrated amplified DNA within each hsr was determined and in 13/16 cases (81%), hsrs were shown to be composed of two or more chromosomal regions. These studies shed light on the mechanism of formation of hsrs, and identify chromosomal regions likely to harbour genes amplified in breast cancer.

Human artificial chromosomes generated by modification of a yeast artificial chromosome containing both human alpha satellite and single-copy DNA sequences

A human artificial chromosome (HAC) vector was constructed from a 1-Mb yeast artificial chromosome (YAC) that was selected based on its size from among several YACs identified by screening a randomly chosen subset of the Centre d'Etude du Polymorphisme Humain (CEPH) (Paris) YAC library with a degenerate alpha satellite probe. This YAC, which also included non-alpha satellite DNA, was modified to contain human telomeric DNA and a putative origin of replication from the human beta-globin locus. The resultant HAC vector was introduced into human cells by lipid-mediated DNA transfection, and HACs were identified that bound the active kinetochore protein CENP-E and were mitotically stable in the absence of selection for at least 100 generations. Microdissected HACs used as fluorescence in situ hybridization probes localized to the HAC itself and not to the arms of any endogenous human chromosomes, suggesting that the HAC was not formed by telomere fragmentation. Our ability to manipulate the HAC vector by recombinant genetic methods should allow us to further define the elements necessary for mammalian chromosome function.

Generation of band-specific painting probes from a single microdissected chromosome

We have developed a modified strategy for the generation of regional probes for human chromosomes by microdissection and degenerate oligonucleotide primed PCR. This modification dramatically increases the efficiency of amplification by pretreatment of the dissected chromatin with topoisomerase I (Topo I) before PCR. This protocol has enabled us to construct region-specific probes for fluorescence in situ hybridization (FISH) from a single microdissected chromosome. Results are presented which convincingly demonstrate that this new method generates high intensity region-specific FISH probes, while at the same time significantly decreasing the time-consuming and labor-intensive aspects of microdissection. The reduction of the number of copies required to generate a useful probe also significantly decreases the risk of contamination during the microdissection process. We believe this advance will allow microdissection to be more widely used in the cytogenetic analysis of chromosome rearrangements in both cancer and hereditary diseases. In addition, this method now makes it possible to construct a series of non-overlapping band-specific DNA microclone libraries to provide complete coverage of individual chromosomes for physical mapping.

Nuclear architecture and the induction of chromosomal aberrations

Progress in fluorescence in situ hybridization, three dimensional microscopy and image analysis has provided the means to study the three-dimensional structure and distribution of chromosome territories within the cell nucleus. In this contribution, we summarize the present state of knowledge of the territorial organization of interphase chromosomes and their topological relationships with other macromolecular domains in the human cell nucleus, and present data from computer simulations of chromosome territory distributions. On this basis, we discuss models of chromosome territory and nuclear architecture and topological consequences for the formation of chromosome exchanges.

Amplification of 19q13.1-q13.2 sequences in ovarian cancer. G-band, FISH, and molecular studies

In this study of ovarian carcinoma, we extended previous findings by performing FISH using chromosome 19 paint and microFISH probes and patient samples with and without abnormalities of chromosome 19 identified by G-banding. Karyotype interpretations of der(19) were confirmed, while additional 19 translocations were also detected by FISH with 19WCP in some cases. Similar FISH studies of ovarian carcinoma cell lines found chromosome 19 abnormalities even after extensive in vitro culture. MicroFISH probes were generated by chromosome microdissection from two cases with hsr(19) and mapped to 19q13.2 and 19q13.1-.2, respectively. FISH with these microFISH probes alone or in combination with a 19WCP probe to four patient samples and seven cell lines showed that 65% of chromosome 19 structural abnormalities contained 19q13.1-q13.2 sequences, sometimes as large hsrs. Ovarian cancer cell lines showed amplification and overexpression of the AKT2 putative oncogene, but not the ERCC-2 DNA repair gene in this chromosomal region. In addition to AKT2, amplification and overexpression of other yet-unidentified genes in the 19q13.1-q13.2 region may contribute to ovarian carcinoma pathogenesis or progression.

Rapid generation of whole chromosome painting probes (WCPs) by chromosome microdissection

A strategy for rapid construction of whole chromosome painting probes (WCPs) by chromosome microdissection has recently been developed. WCPs were prepared from 20 copies of each target chromosome microdissected from normal human metaphase chromosomes and then directly amplified by PCR using a universal primer. Fifteen WCPs, including chromosomes 1, 3, 6, 7, 9, 12, 13, 14, 15, 17, 19, 20, 21, 22, and X, have been generated using this strategy. The probe complexity and hybridization specificity of these WCPs have been characterized by gel electrophoresis and fluorescence in situ hybridization. Analysis of WCPs constructed by chromosome microdissection indicated that microdissected WCPs invariably provide strong and uniform signal intensity with no cytologically apparent cross-hybridization. To demonstrate the application of WCPs generated from microdissection, we have used these probes to detect complex chromosome rearrangements in a melanoma cell line, UM93-007. Two different translocations involving three chromosomes [t(1;3;13) and t(1;7;13)] have been identified, both of which were undetectable by conventional banding analysis. Further application of these WCPs (including generation of WCPs from mouse and other species) should greatly facilitate the cytogenetic analysis of complex chromosome rearrangements.

Expression of cytoplasmic and nuclear Survivin in primary and secondary human glioblastoma

Clinically, human glioblastoma (GBM) may develop de novo or from a low-grade glioma (secondary GBM), and molecular alterations in the two pathways may differ. This study examined the status of Survivin expression and apoptosis in 30 primary and 26 secondary GBMs. Our results show that cytoplasmic Survivin positivity was significantly (P<0.001) more frequent in primary GBMs (83%) than that in secondary GBMs (46%). In addition, an inverse correlation of cytoplasmc Survivin positivity with GBM apoptotic index, and a positive association between cytoplasmic Survivin and size of the tumours were observed. These results suggest that cytoplasmic Survivin, via its antiapoptotic function, may be involved in the tumorigenesis of many primary GBMs, but only in a small fraction of secondary GBMs. Furthermore, the overall progression times from low-grade precursor lesions to secondary GBMs were significantly shorter (P<0.05) in cytoplasmic Survivin-positive cases (mean, 15.6 months) than those in Survivin-negative cases (mean, 23.8 moths), and the positive expression level of Survivin in cytoplasm was upregulated in most secondary GBMs when compared to matched pre-existing low-graded lesions. These results suggest that the increased accumulation of Survivin in the cytoplasm of more malignant glioma cells may prove to be a selective advantage, thus accelerating progression to a more aggressive phenotype.

Transcriptome sequencing of sea cucumber (Apostichopus japonicus) and the identification of gene-associated markers

Sea cucumber (Apostichopus japonicus) is an ecologically and economically important species in East and South-East Asia. This project aimed to identify large numbers of gene-associated markers and differentially expressed genes (DEGs) after lipopolysaccharides (LPS) challenge in A. japonicus using high-throughput transcriptome sequencing. A total of 162 million high-quality reads of 174 million raw reads were obtained by deep sequencing using Illumina HiSeq™ 2000 platform. Assembly of these reads generated 94 704 unigenes, with read length ranging from 200 to 16 153 bp (average length of 810 bp). A total of 36 005 were identified as coding sequences (CDSs), 32 479 of which were successfully annotated. Based on the assembly transcriptome, we identified 142 511 high-quality single nucleotide polymorphisms (SNPs). Among them, 33 775, 63 120 and 45 616 were located in sequences without predicted CDS (non-CDSs), CDSs and untranslated regions (UTRs), respectively. These putative SNPs included 82 664 transitions and 59 847 transversions. Totally, 89 375 (59.1%) were distributed in 15 473 known genes. A total of 6417 microsatellites were detected in 5970 unigenes, 3216 of which were annotated and 2481 were successfully subjected for primer design. The numbers of simple sequence repeats (SSRs) identified in non-CDSs, CDSs and UTRs were 2367, 2316 and 1734. These potential SNPs and SSRs are expected to provide abundant resources for genetic, evolutionary and ecological studies in sea cucumber. Transcriptome comparison revealed 1330, 1347 and 1291 DEGs in the coelomocytes of A. japonicus at 4 h, 24 h and 72 h after LPS challenge, respectively. Approximately 58.4% (1802) of total DEGs have been successfully annotated.

Expression of the zinc finger gene EVI-1 in ovarian and other cancers

The EVI-1 gene was originally detected as an ectopic viral insertion site and encodes a nuclear zinc finger DNA-binding protein. Previous studies showed restricted EVI-1 RNA or protein expression during ontogeny; in a kidney and an endometrial carcinoma cell line; and in normal murine oocytes and kidney cells. EVI-1 expression was also detected in a subset of acute myeloid leukaemias (AMLs) and myelodysplasia. Because EVI-1 is expressed in the urogenital tract during development, we examined ovarian cancers and normal ovaries for EVI-1 RNA expression using reverse transcription polymerase chain reaction (RT-PCR) and RNAase protection. Chromosome abnormalities were examined using karyotypes and whole chromosome 3 and 3q26 fluorescence in situ hybridisation (FISH). RNA from six primary ovarian tumours, five normal ovaries and 47 tumour cell lines (25 ovarian, seven melanoma, three prostate, seven breast and one each of bladder, endometrial, lung, epidermoid and histiocytic lymphoma) was studied. Five of six primary ovarian tumours, three of five normal ovaries and 22 of 25 ovarian cell lines expressed EVI-1 RNA. A variety of other non-haematological cancers also expressed EVI-1 RNA. Immunostaining of ovarian cancer cell lines revealed nuclear EVI-1 protein. In contrast, normal ovary stained primarily within oocytes and faintly in stroma. Primary ovarian tumours showed nuclear and intense, diffuse cytoplasmic staining. Quantitation of EVI-1 RNA, performed using RNAase protection, showed ovarian carcinoma cells expressed 0 to 40 times the EVI-1 RNA in normal ovary, and 0-6 times the levels in leukaemia cell lines. Southern analyses of ovarian carcinoma cell lines showed no amplification or rearrangements involving EVI-1. In some acute leukaemias, activation of EVI-1 transcription is associated with translocations involving 3q26, the site of the EVI-1 gene. Ovarian carcinoma karyotypes showed one line with quadruplication 3(q24q27), but no other clonal structural rearrangements involving 3q26. However, whole chromsome 3 and 3q26 FISH performed on lines with high EVI-1 expression showed translocations involving chromosome 3q26. EVI-1 is overexpressed in ovarian cancer compared with normal ovaries, suggesting a role for EVI-1 in solid tumour carcinogenesis or progression. Mechanisms underlying EVI-1 overexpression remain unclear, but may include rearrangements involving chromosome 3q26.

Rapid generation of region-specific genomic clones by chromosome microdissection: isolation of DNA from a region frequently deleted in malignant melanoma

Malignant melanoma is frequently characterized by the deletion of the long arm of chromosome 6 (usually encompassing 6q16-q21). In an effort to saturate this region with DNA markers, microdissection and molecular cloning of DNA from banded human metaphases recent development of a novel chromosome microdissection scheme that omits microchemical manipulation of DNA. Microdissection was targeted on band 6q21. Direct PCR amplification of dissected DNA was first used as a probe in chromosomal in situ hybridization of normal metaphases to confirm the specificity of material excised for cloning. A genomic library of 20,000 clones, which is highly enriched for sequences encompassing 6q21, was then constructed. Clones from this library have been mapped against a human-rodent somatic cell hybrid mapping panel that divides chromosome 6 into seven regions, confirming the localization of probes within the target region. Direct PCR amplification of DNA excised by microdissection greatly simplifies and facilitates this chromosome band-specific cloning strategy. The isolation of microclones from this region of chromosome 6 should assist in establishing a physical map of the melanoma deletion region.

The significance of LMO2 expression in the progression of prostate cancer

LIM domain only 2 (LMO2) proteins are important regulators in determining cell fate and controlling cell growth and differentiation. This study has investigated LMO2 expression in human prostatic tissue specimens, prostate cancer cell lines, and xenografts; and has assessed the possible role and mechanism of LMO2 in prostate carcinogenesis. Immunohistochemical analysis on a tissue microarray consisting of 91 human prostate specimens, including normal, prostatic hyperplasia, high-grade prostatic intraepithelial neoplasia, and invasive carcinoma, revealed that overexpression of LMO2 was significantly associated with advanced tumour stage, as measured by Gleason score (p = 0.012), as well as with the development of distant metastasis (p = 0.018). These data were supported by quantitative real-time PCR experiments, where LMO2 mRNA levels were found to be significantly higher in prostate tumour specimen than in normal epithelium (p = 0.037). The expression of LMO2 in cell lines and xenografts representing androgen-dependent (AD) and androgen-independent (AI) prostate cancer stages was further studied. Consistent with the in vivo data, LMO2 mRNA and protein were found to be overexpressed in the more aggressive AI cells (PC3, DU145, and AI CWR22 xenografts) compared with less aggressive AD cells (LNCaP and AD CWR22 xenografts). Furthermore, stable introduction of LMO2 into LNCaP cells conferred enhanced cell motility and invasiveness in vitro, accompanied by down-regulation of E-cadherin expression. Taken together, these findings provide the first evidence to support the hypothesis that LMO2 may play an important role in prostate cancer progression, possibly via repression of E-cadherin expression.

Clonal chromosome abnormalities in 54 cases of ovarian carcinoma

As a prelude to assessing the relationship of chromosome alterations to clinical outcome in ovarian carcinoma, we report on the cytogenetic analysis on short-term cultures from 54 patients. All patients had histopathologically confirmed malignancy, with the majority of cases demonstrating serous ovarian adenocarcinomas. Structural alterations were evident in 52 cases, whereas numeric changes were identified in 13 cases. The most notable numeric abnormalities were loss of the X-chromosome (9/13 total cases) and +7 (3/9 diploid cases). Structural alterations most frequently involved chromosomes 1, 3, 6, 7, 11, and 12. Chromosomal breakpoints were shown to cluster in several chromosomal banding regions, including 1p36, 1p11-q21, 3p23-p10, 7p (especially 7p22), 11p, 11q, 12p13-q12, and 12q24. The frequency of structural alterations involving the following chromosome arms was found to be significantly increased: 1p (p < 0.01), 7p (p < 0.01), 11p (p < 0.01), 11q (p < 0.05), and 12p (p < 0.05). An analysis of the net gain or loss of chromosome segments was also performed, with the most consistent tendency observed being over-representation of 1q and chromosome 7, deletion of 1p, and loss of the X chromosome.

Recurrent chromosome changes in 62 primary gastric carcinomas detected by comparative genomic hybridization

Comparative genomic hybridization (CGH) has been applied to detect recurrent chromosome alterations in 62 primary gastric carcinomas. Several nonrandom chromosomal changes, including gains of 8q (31 cases, 50%), 20q (29 cases, 47%) with a minimum gain region at 20q11. 2-q12, 13q (21 cases, 34%) with a minimum gain region at 13q22, and 3q (19 cases, 31%) were commonly observed. The regions most frequently lost included: 19p (23 cases, 37%), 17p (21 cases, 33%), and 1p (14 cases, 23%). High copy number gain (DNA sequence amplification) was detected in 6 cases. Amplification of 8q23-q24.2 and 20q11.2-q12 were observed in 3 cases. Gain of 20q and loss of 19p were confirmed by fluorescence in situ hybridization using corresponding bacterial artificial chromosomes (BAC) clones from those regions. The gain and loss of chromosomal regions identified in this study provide candidate regions involved in gastric tumorigenesis.

Overexpression of clusterin correlates with tumor progression, metastasis in gastric cancer: a study on tissue microarrays

Clusterin (CLU) is expressed in a wide variety of human tissues and fluids. Overexpression of cytoplasmic clusterin (sCLU) has been implicated in cancer development and progression. The aim of the present study is to evaluate the association of sCLU overexpression with clinicopathological features of human gastric carcinomas (GC).We constructed a gastric cancer tissue microarray containing 173 primary gastric carcinomas and 70 paired non-neoplastic mucosa specimens. The expression of sCLU was studied by immunohistochemistry. The correlations between sCLU expression and clinicopathological features, p53 abnormality, as well as Ki67 activation were analyzed. Overexpressions of sCLU was detected in 28.5% (n=165) of primary GCs by immunohistochemical staining, but not in non-neoplastic mucosa. Clinical association study found that overexpression of sCLU was significantly correlated with lymph-node metastasis (p < 0.001), tumor invasion (p < 0.001) and TNM stage (p < 0.001). In Kaplan-Meier survival analysis, overexpression of sCLU was significantly correlated with unfavorable survival in advanced GCs (p < 0.03). Furthermore, the association of sCLU with abnormal expression of p53 was ascertained. These results suggested that overexpression of sCLU was involved in the progression of GC and it's oncogenic function might be associated with p53 abnormality. Overexpression of sCLU seems to be related with patient's shorter survival in late stage GC.

Amplification and overexpression of aurora kinase A (AURKA) in immortalized human ovarian epithelial (HOSE) cells

Immortalization is an early and essential step of human carcinogenesis. Amplification of chromosome 20q has been shown to be a common event in immortalized cells and cancers. We have previously reported that gain and amplification of chromosome 20q is a non-random and common event in immortalized human ovarian surface epithelial (HOSE) cells. The chromosome 20q harbors genes including TGIF2 (20q11.2-q12), AIB1 (20q12), PTPN1 (20q13.1), ZNF217 (20q13.2), and AURKA (20q13.2-q13.3), which were previously reported to be amplified and overexpressed in ovarian cancers. Some of these genes may be involved in immortalization of HOSE cells and represent crucial premalignant changes in ovarian surface epithelium. Investigation of the involvement of these genes was examined in four pairs of pre-crisis (preimmortalized) and post-crisis (immortalized) HOSE cells. Overexpression of AURKA (Aurora kinase A), also known as BTAK and STK15, by both real time-quantitative polymerase chain reaction (RT-QPCR) and Western blotting was detected in all the four immortalized HOSE cells examined while overexpression of AIB1 and ZNF217 was observed in two of four immortalized HOSE cells examined. Overexpression of TGIF2 and PTPN1 was not significant in our immortalized HOSE cell systems. The degree of overexpression of AURKA was shown to be closely associated with the amplification of chromosome 20q in immortalized HOSE cells. Fluorescence in situ hybridization (FISH) with labeled P1 artificial clone (PAC) confirmed the amplification of the chromosomal region (20q13.2-13.3) where AURKA resides. DNA amplification of AURKA was also confirmed using semi-quantitative PCR. Our study showed that amplification and overexpression of AURKA is a common and significant event during immortalization of HOSE cells and may represent an important premalignant change in ovarian carcinogenesis.

Gain of 9p in the pathogenesis of polycythemia vera

Polycythemia vera (PV) is a clonal stem cell disorder characterized by excessive erythrocyte production, resulting in absolute erythrocytosis. No specific structural chromosomal abnormalities have been reported in PV to date. We have observed two cases of PV with an extra i(9)(p10) as the sole anomaly, and FISH analysis using a 9p-specific chromosome microdissection probe showed that two other PV patients previously identified as having an add(18p) and an add(1p) as the primary changes actually carried a der(18)t(9;18)(p12;p11.2) and a der(1)t(1;9)(p12;p12), respectively. The same FISH assay was employed to evaluate domain signals on interphase cells of 15 more cases of PV with normal karyotypes and five normal controls. Two patients were observed with a significant increase in the percentage of cells with three domain signals. Our results strongly indicate that an additional i(9)(p10) is a new and recurrent primary chromosome anomaly in PV, and, in consideration of trisomy 9 being one of the most common anomalies in PV, amplification of a gene or genes on 9p, but not on 9q, may play a crucial role in the pathogenesis of PV.

Chromosome 8p deletion is associated with metastasis of human hepatocellular carcinoma when high and low metastatic models are compared

Recently, we found that chromosome 8p deletion might be associated with hepatocellular carcinoma (HCC) metastasis by analyzing the differences in chromosomal alterations between primary tumors and their matched metastatic lesions of HCC with comparative genomic hybridization (CGH) (Qin et al. 1999). To further confirm this interesting finding, the genomic changes of two models bearing human HCC with different metastatic potentials (LCI-D20 and LCI-D35), and the new human HCC cell line with high metastatic potential (MHCC97) were analyzed by CGH. Gains on 1q, 6q, 7p, and 8q, and losses on 13p, 14p, 19p, 21, and 22 were detected in both LCI-D20 and LCI-D35 models. However, high copy number amplification of a minimum region at 1q12-q22 and 12q, and deletions on 1p32-pter, 3p21-pter, 8p, 9p, 10q, 14q, and 15p were detected only in the LCI-D20 model. Gains on 1p21-p32, 2p13-p21, 6p12-pter, 9p, 15q, and 16q11-q21, and losses on 2p23-pter, 4q24-qter, 7q31-qter, 12q, 17p, and 18 were detected only in the LCI-D35 model. The chromosomal aberration patterns in the MHCC97 cell line were similar to its parent LCI-D20 model, except that gains on 19q and losses on 4, 5, 10q, and 13q were found only in the cell line. These results provide some indirect clues to the metastasis-related chromosomal aberrations of HCC and further support the finding that 8p deletion is associated with HCC metastasis. 1q12-22 and 12q might harbor a novel oncogene(s) that contributes to the development and progression of HCC. Amplification on 8q and deletions on 4q and 17p may be not necessary for HCC metastasis.

Childhood-onset schizophrenia/autistic disorder and t(1;7) reciprocal translocation: identification of a BAC contig spanning the translocation breakpoint at 7q21

Childhood-onset schizophrenia (COS) is defined by the development of first psychotic symptoms by age 12. While recruiting patients with COS refractory to conventional treatments for a trial of atypical antipsychotic drugs, we discovered a unique case who has a familial t(1;7)(p22;q21) reciprocal translocation and onset of psychosis at age 9. The patient also has symptoms of autistic disorder, which are usually transient before the first psychotic episode among 40-50% of the childhood schizophrenics but has persisted in him even after the remission of psychosis. Cosegregating with the translocation, among the carriers in the family available for the study, are other significant psychopathologies, including alcohol/drug abuse, severe impulsivity, and paranoid personality and language delay. This case may provide a model for understanding the genetic basis of schizophrenia or autism. Here we report the progress toward characterization of genomic organization across the translocation breakpoint at 7q21. The polymorphic markers, D7S630/D7S492 and D7S2410/D7S646, immediately flanking the breakpoint, may be useful for further confirming the genetic linkage for schizophrenia or autism in this region. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:749-753, 2000. Published 2000 Wiley-Liss, Inc.