Fluorescence in situ hybridization improves cytogenetic results in the analysis of hepatoblastoma

Hepatoblastoma (HB) is the most frequent malignant liver tumor in children. Cytogenetic data indicate the presence of recurring trisomies of the chromosomes 2, 8, and 20, but more work is needed to clarify their incidence and prognostic significance. Cytogenetic analysis is limited by the requirement of suitable cells in metaphase. A different method that increases analysis sensitivity is fluorescence in situ hybridization (FISH). We studied 20 cases of hepatoblastoma; FISH analysis obtained results in 10 cases of HB with no informative karyotype. In 5 of 10 of these cases at least one trisomic clone was detected, which always coexisted with a population of diploid cells. These results confirm that trisomy 20 and/or 2 and 8 coexisting with diploid cells is a frequent finding in hepatoblastoma and provide further support to the clonal evolution theory: indeed, trisomy 20 was the most frequently detected abnormality, followed by trisomy of chromosomes 2 and 8. In view of the high incidence of recurrent trisomies, FISH analysis should be recommended in all the cases of HB with no informative karyotype.     

Fluorescence in situ hybridization in diagnostic cytology

Fluorescence in situ hybridization (FISH) is a technique that uses fluorescently labeled DNA probes to detect chromosomal alterations in cells. FISH can detect various types of cytogenetic alterations including aneusomy (ie, abnormalities of chromosome copy number), duplication, amplification, deletion, and translocation. Because tumor cells generally contain chromosomal alterations, FISH is able to detect cells that have chromosomal abnormalities consistent with neoplasia in exfoliative and aspiration cytology specimens. This review will discuss the utility of FISH for the detection of bladder, lung, pancreatobiliary, and esophageal carcinoma in cytologic specimens.     

Combined binary ratio labeling fluorescence in situ hybridization analysis of chordoma

Chordoma is a rare, low- to intermediate-grade malignant tumor involving the axial spine. Cytogenetic data on these tumors have been limited to 25 cases. The findings of clonal chromosome aberrations in five new cases are presented. One of these and two previously reported cases have been studied with multicolor combined binary ratio labeling fluorescence in situ hybridization (COBRA-FISH). The karyotypes were near-diploid, mostly with several numerical and structural aberrations. There were multiple imbalances, with loss of segments from 1p, 3p, 3q, 9p, and chromosome 10 seen in two to four of the seven cases. No clustering of breakpoints was seen and no recurrent recombination between chromosomes was detected. The findings are consistent with previous data and indicate that chordoma tumor development is associated with multiple, nonrandom losses including chromosome segments that are frequently involved in many other solid tumors.     

Fluorescence in situ hybridization analysis of HER-2/neu in brushings of normal oral mucosa

Oncogene alterations have been clearly demonstrated to be related to the carcinogenesis and progression of oral squamous cell carcinoma (OSCC). However, the analysis of these alterations for screening and early diagnostic purposes generally requires invasive techniques for surgical removal of pathological epithelium. The aim of the present study was to assess the feasibility of fluorescence in situ hybridization (FISH) analysis of HER-2/neu amplification in oral mucosa brushings and to compare the HER-2/neu status with the history and smoking and drinking habits of healthy subjects. Cells obtained by centrifugation of oral brushings from 21 subjects (overall no. of cells: 5125) were suspended in physiological saline and fixed onto two slides for cytological evaluation and FISH analysis (dual-target, dual-color fluorescence assay) of the HER-2/neu gene and CEP17 centromere. A mean of 89.8% of the cells showed two HER-2/neu signals and a mean of 94% had two CEP17 signals at fluorescent microscopy. Finally, a mean of 96% of cells with HER-2/neu / CEP17 had a ratio equal to 1. No association between smoking and drinking habits, age and the HER-2/neu and CEP17 characteristics evaluated by FISH was found.     

Fluorescence in situ hybridization: A brief review

Fluorescence in situ hybridization (FISH) is used for many purposes, including analysis of chromosomal damage, gene mapping, clinical diagnostics, molecular toxicology and cross-species chromosome homology. FISH allows an investigator to identify the presence and location of a region of cellular DNA or RNA within morphologically preserved chromosome preparations, fixed cells or tissue sections. This report describes in situ hybridization, and discusses the past, present and future applications of this method for genetic analysis and molecular toxicology. © 1996 Wiley-Liss, Inc.     

Fluorescence in situ hybridization, comparative genomic hybridization, and other molecular biology techniques in the analysis of effusions

Over the last 20 yr, the introduction of immunocytochemistry as a diagnostic tool has dramatically revolutionized diagnostic pathology. With the introduction of molecular methods as part of the diagnostic armamentarium, the practicing pathologist is facing the new challenge of grasping novel concepts of the molecular cytogenetics era. Herein, we review the diagnostic contribution of ancillary molecular techniques, including fluorescent and chromogenic in situ hybridization, telomerase assays, loss of heterozygosity, comparative genomic hybridization (CGH), and microarray-based CGH, for the practicing cytopathologists and discuss how these techniques will help pathologists in decision-making.     

Fluorescence in situ hybridization analysis of whole-arm 7;12 translocations in hematologic malignancies

Cytogenetic analysis of one case of acute myeloid leukemia (AML), one of acute lymphoblastic leukemia (ALL), one of refractory anemia with excess of blasts (RAEB), and one of acute mixed lineage leukemia (AMLL) with unbalanced 7;12 translocations mapped the breakpoints to the centromeres on both chromosomes. The rearrangements were interpreted as the whole-arm translocations der(7;12)(q10;q10) in the AML and ALL and der(7;12)(p10;q10) in the RAEB and AMLL. However, further analysis by metaphase and/or interphase fluorescence in situ hybridization (FISH) showed centric fusion only in the AML and ALL. In the RAEB and AMLL, centromeric material from chromosome 7 but not from 12 was present in the derivative chromosome. Whereas the t(7;12) resulted in loss of 12p in all four cases, the corresponding chromosome 7 imbalances differed—monosomy for 7q in the RAEB and AMLL and monosomy for 7p in the AML and ALL. Six hematologic neoplasms with unbalanced whole-arm or near-centromeric 7;12 translocations and seven dic(7;12) with juxtacentromeric breakpoints have been reported previously: 2 AML, 1 RAEB in transformation, and 10 ALL. All karyotypically informative cases had loss of 12p material. All but one of the cases with combined 7p and 12p deletion were ALL, whereas all cases with 7q and 12p loss showed myeloid differentiation. No particular clinical, morphologic, or immunophenotypic features seem to characterize ALLs with t(7;12). AMLs with an unbalanced t(7;12), often together with 5q deletions, might be associated with previous genotoxic exposure and poor prognosis.     

荧光原位杂交在滑膜肉瘤诊断中的应用

滑膜肉瘤是儿童及青少年期常见的软组织肿瘤,约占软组织恶性肿瘤的2％～10％。好发于大关节周围,也可见于其他关节、软组织,还可发生于肺、前列腺、肾等脏器。组织学可分为双相分化型、单相纤维型、单相上皮型、低分化型H0,其中前2种最常见。由于其形态多样,发病部位广泛,免疫组织化学染色又缺乏特异的抗体,有时会造成病理诊断的困难。细胞和分子遗传学研究发现,90％以上的滑膜肉瘤存在特异的t（X;18）（p11．2;q11．2）,导致位于18号染色体SYT基因易位,和位于X染色体上SSX基因产生SYT—SSX融合基因。目前国内检测该融合基因均使用逆转录-聚合酶链反应（RT—PCR）。我们收集儿童滑膜肉瘤4例,探讨运用荧光原位杂交（FISH）法对甲醛固定、石蜡包埋组织检测其融合基因的可行性。     

Fluorescence in situ hybridization in diagnosis of urinary bladder cancer

The paper presents preliminary results of a study of the diagnosis of urinary bladder cancer by fluorescence in situ hybridization (FISH). Specific chromosomal aberrations are shown to be detectable in both proper tumor tissue and urine from patients with urinary bladder cancer; and the pattern of these changes coincides. FISH may identify cells with genetic disorders in urine long before the clinical symptoms of a recurrence occur.     

Fluorescence in situ hybridization analysis of chromosome 12 anomalies in semen cells from patients with carcinoma in situ of the testis

Carcinoma in situ (CIS) of the testis is the precursor of seminomas and non-seminomatous germ cell tumours of the adult testis. A marked cytogenetic anomaly, the isochromosome of the short arm of chromosome 12 [i(12p)], has been demonstrated in over 80 per cent of all histological varieties of testicular germ cell tumours (TGCTs). In the remaining group of i(12p)-negative TGCTs, an overrepresentation of chromosome 12p sequences has been found. The i(12p) chromosome and overrepresentation of 12p sequences in CIS cells have also been reported. In order to establish whether numerical and/or structural aberrations of chromosome 12 can be found in CIS cells exfoliated into seminal fluid, semen specimens from ten patients with CIS lesions were investigated using bicolour double fluorescence in situ hybridization (FISH). The two DNA probes used, p alpha 12H8 and YAC 5, specifically detect the centromeric region of chromosome 12 and a subregion, p11.2-p12.1, on the short arm of chromosome 12, respectively. Ejaculates of ten azoospermic or oligozoospermic infertile males, presumably CIS-free, were used as negative controls. Nuclei exhibiting three or more chromosome 12 signals were found to be present in a significantly larger number in the patient samples than in the control samples. Nuclei with five or more chromosome 12 signals were observed in eight out of the ten patients. Morphologically similar arrangements to i(12p) were observed in some of the ejaculates. These results demonstrate the potential of FISH in the early detection of CIS and TGCTs in males at high risk.     

Fluorescence in situ hybridization analysis of HER-2/neu, c-myc, and p53 in endometrial cancer

Our objective was to evaluate the association between HER-2/neu, c-myc, p53, and clinicopathologic variables in endometrial cancer using fluorescence in situ hybridization (FISH) cytogenetic analysis. FISH analysis for HER-2/neu, c-myc, and p53 was performed on 47 endometrial cancer specimens. Amplification of HER-2/neu was seen in 4/47 (8.5%) cases and amplification of c-myc was seen in 7 of 47 (15%) cases; neither was associated with adverse clinicopathologic variables or survival. Deletion of p53 was seen in 31/47 (66%) cases and was associated with poor histologic grade (P = 0.008). There was no impact of genetic alterations on overall survival or disease-free interval. Grade 3 tumor was associated with poor overall survival (P = 0.032). This study found that p53 deletion is a common genetic alteration in endometrial cancer and is associated with poor-grade tumors.     

Fluorescence in situ hybridization for identification of microorganisms in acute chorioamnionitis

The relevance of microorganisms in preterm birth is still under discussion. Using a diagnostic fluorescence in situ hybridization probe panel, we visualized Staphylococcus aureus and Streptococcus mitis group in two cases of acute chorioamnionitis. This technique provides spatial resolution and quantity of bacteria, clarifying the epidemiology and pathogenic pathways of acute chorioamnionitis.     

荧光原位杂交技术检测多发性骨髓瘤复杂核型异常

目的探讨多重荧光原位杂交(multiplex fluorescence in situ hybridization,M-FISH)技术联合荧光原位杂交(fluorescence in situ hybridization,FISH)技术在检测多发性骨髓瘤(multiplemyeloma,MM)染色体异常中的应用价值及13q14缺失、IgH相关易位和17p13缺失的发生率。方法联合应用常规细胞遗传学(conventional cytogenetics,CC)方法及M-FISH和一组包括13q14(D13S319),14q32(IgH基因)和17p13(p53基因)探针的FISH技术分析了7例伴有复杂染色体异常的MM患者骨髓标本。结果M-FISH明确了CC分析中没有明确的异常,共检出12种染色体数目异常和29种结构异常,其中,1号染色体异常、13号染色体缺失和与14q32相关的易位最为多见。FISH检出6例伴有13q14缺失;4例伴有17p13缺失;5例伴有一个14q32相关易位,两例还伴有涉及两个14q32的易位。结论M-FISH联合FISH技术可以明确CC分析中复杂染色体异常,并发现和纠正CC分析中漏检及误检的异常,为MM染色体异常的研究提供了一种理想的     

Fluorescence in situ hybridization study of HER-2/neu oncogene amplification in prostate cancer.

Prostate cancer is a serious disease affecting men worldwide and treatment compromises the quality of life of prostate cancer patients. We conducted a study of 88 cases of prostate cancer in an attempt to identify prognostic biomarkers that can distinguish aggressive cases that must be treated immediately. HER-2/neu oncogene amplification was initially studied because amplification of this gene has been reported in many other cancers, including those studied in this laboratory. Fluorescence in situ hybridization (FISH) using a HER-2/neu gene probe with a chromosome 17 centromere control probe was performed on formalin-fixed, paraffin-embedded tissues. Of a total of 86 cases successfully analyzed, only 8 (9.3%) were found to be amplified. This frequency was lower than the frequency of amplification found in other cancers studied. Furthermore, no case was found where the level of amplification can be considered high. Only one case was found to have moderate amplification. The rest of the positive cases can all be classified as low amplification. Thus, while we have demonstrated that FISH is a sensitive technique for detecting oncogene amplification, the frequency and level of HER-2/neu amplification detected in prostate cancer seem to be lower than those in most cancers that we studied. In view of the fact that HER-2/neu amplification does not seem to play as significant a role, exploration of other biomarkers in prostate cancer is warranted.     

孕早期滋养细胞的荧光原位杂交

孕早期滋养细胞的荧光原位杂交，是产前诊断方法学上的一项新内容，并已展现出良好的应用价值和前景。为此，我们对18例孕早期滋养细胞用PY3，4探针进行杂交，除2例计数300个细胞外，其余各例均计数500个细胞。结果15例标本有杂交信号，信号出现率为88．6％（73．2－98．8％），3例未见杂交信号，结果与核型分析（15例男性，3例女性）一致。根据我们的实践体会，还对计数时细胞的选择和影响结果的有关因素进行了讨论。     

Comparative analysis of glutamate transporter expression in rat brain using differential double in situ hybridization

 This study compares the mRNA expression pattern for the three glutamate transporters EAAC1, GLT1 and GLAST in rat brain, using a sensitive non-radioactive in situ hybridization technique. The results confirm the predominantly neuronal localization of EAAC1 mRNA, the astroglial and ependymal localization of GLAST mRNA and the astroglial and neuronal localization of GLT1 mRNA. Further, we demonstrate, using a novel differential double hybridization protocol, that the presence of GLT1 mRNA in neurons is more widespread than previously thought, and that it encompasses the majority of neurons in the neocortex, neurons in the external plexiform layer in the olfactory bulb, neurons in dorsal and ventral parts of the anterior olfactory nucleus, the majority of neurons in the anteromedial thalamic nuclei, the CA3 pyramidal neurons in the hippocampus and neurons in the inferior olive. In addition, we demonstrate marked variations in the expression levels of GLT1 and GLAST mRNAs in different brain areas, suggesting that their mRNA levels are regulated by different mechanisms. Finally, for EAAC1 we demonstrate also a widespread distribution and a marked heterogeneity in the expression levels. EAAC1 is strongly expressed by a heretofore unrecognized group of cells in white matter tracts such as the corpus callosum, fimbria-fornix or anterior commissure. Also, strong EAAC1 expression is present in groups of scattered cells in grey matter areas of much of the forebrain and the cerebellum. These results provide more detailed information about the precise cellular localization of these three glutamate transporters and their regulation at the mRNA level. Accepted: 29 January 1998     

Fluorescence in situ hybridization in plants: recent developments and future applications

Fluorescence in situ hybridization (FISH) was developed more than 30 years ago and has been the most paradigm-changing technique in cytogenetic research. FISH has been used to answer questions related to structure, mutation, and evolution of not only individual chromosomes but also entire genomes. FISH has served as an important tool for chromosome identification in many plant species. This review intends to summarize and discuss key technical development and applications of FISH in plants since 2006. The most significant recent advance of FISH is the development and application of probes based on synthetic oligonucleotides (oligos). Oligos specific to a repetitive DNA sequence, to a specific chromosomal region, or to an entire chromosome can be computationally identified, synthesized in parallel, and fluorescently labeled. Oligo probes designed from conserved DNA sequences from one species can be used among genetically related species, allowing comparative cytogenetic mapping of these species. The advances with synthetic oligo probes will significantly expand the applications of FISH especially in non-model plant species. Recent achievements and future applications of FISH and oligo-FISH are discussed.

     

Fluorescence in situ hybridization analysis of allelic losses involving the long arm of chromosome 17 in NF1-associated neurofibromas

Neurofibromatosis type 1 (NF1) is a common autosomal dominant condition associated with germline mutations of the NF1 gene located at chromosome band 17q11.2. Molecular analysis of a number of NF1-specific tumors has shown the inactivation of both NF1 alleles during tumorigenesis, supporting the tumor suppressor hypothesis for the NF1 gene. Using interphase dual-color fluorescence in situ hybridization (FISH) technique on paraffin-embedded tissues, we studied 11 plexiform, 4 cutaneous, and 6 subcutaneous neurofibromas. Cytogenetic analysis was conducted using two probes, one specific for the NF1 region (RP11-229K15) and one for the centromeric region of chromosome 17 as control. No large somatic deletions were found. Only in one of the plexiform neurofibromas loss of a whole chromosome 17 was observed. If we assume that dual-color FISH analysis is sensitive enough to detect the majority of large somatic deletions present, then other mutational mechanisms affecting the NF1 gene are probably involved in neurofibroma formation, and other tumor suppressor genes may play an important role in NF1 tumorigenesis.     

Fluorescence in situ hybridization to improve the diagnosis of endocarditis: a pilot study

Infective endocarditis is a rare but life-threatening disease associated with high mortality. Early diagnosis of the causative microorganism is critical to patient outcome. However, conventional diagnostic methods are often unsatisfactory in achieving this goal. As a proof of concept, we applied fluorescence in situ hybridization (FISH) for detection and identification of bacteria in histological sections of heart valves. Biopsy specimens from 54 suspected endocarditis patients were obtained during valve surgery and analysed via FISH. Specimens were screened with a probe panel that identifies the most common bacteria implicated in endocarditis. Results were compared with those of culture-based diagnostics and clinical data. Discrepant results were subjected to comparative sequence analysis of PCR-amplified 16S rRNA genes. FISH detected bacteria in 26 of the 54 heart valves. FISH allowed successful diagnosis of infective endocarditis in five of 13 blood culture-negative cases and in 11 of 37 valve culture-negative cases, showing the bacteria within their histological context. This technique allows the simultaneous detection and identification of microorganisms at the species or genus level directly from heart valves and might be a valuable tool for diagnosis of endocarditis.