Multi-parameter fluorescence-activated cell sorting and analysis of stem and progenitor cells in myeloid malignancies

Owing to the discovery that rare leukemia-initiating cells (or leukemia stem cells, LSC) give origin to and propagate a hierarchical cellular organization of variably differentiated leukemic blasts, the analysis of precisely defined stem and progenitor cells have increasingly gained importance. Emergence of multi-parameter high-speed fluorescence-activated cell sorting (FACS) for the subfractionation of hematopoietic progenitor cells has allowed research on the biology of the cell-of-origin for LSCs and of LSCs as potential (or essential) therapeutic targets that may escape chemotherapy and consequently contribute to disease relapse. This review introduces the current state-of-the-art methods for the fractionation of hematopoietic stem and progenitor cells, with particular focus on myeloid malignancies. As many aspects of human normal and malignant hematopoiesis are frequently modeled in animal studies, we also provide an overview of hematopoietic stem and progenitor cell purification methods that are commonly utilized for research in murine models of disease.     

Rapid detection of human chromosome 21 aberrations by in situ hybridization.

Plasmid clones containing up to 94 kilobases of single-copy DNA from band q22.3 of chromosome 21 and a complete pool of insert DNA from a chromosome 21 recombinant library have been used to rapidly detect numerical and structural aberrations of chromosome 21 by in situ hybridization in both metaphase and interphase cells. A trisomic karyotype, diagnostic of Down syndrome, is readily detected in nonmitotic cells because the majority of their nuclei exhibit three discrete foci of hybridization, in contrast to normal diploid cells, which show two foci. Chromosomal translocations involving chromosome 21 sequences were also detected with these probes, and the intranuclear location of 21q22.3 DNA sequences in "normal" human brain neurons was established with the plasmid DNA probe set. These results suggest that chromosome 21-specific probes may have utility in clinical diagnostics, especially by facilitating the direct analysis of interphase cells.     

Applications and technical challenges of fluorescence in situ hybridization in stem cell research

Stem cell research, maintenance, and manipulations have advanced significantly in recent years, and we now witness successful clinical applications of stem therapies. However, challenges in regard to karyotypic stability and the ploidy status of stem cell lines have been addressed only marginally. Our approach to develop technology to address these highly relevant issues is based on fluorescence in situ hybridization (FISH) using nonisotopically labeled DNA probes. As a single cell analysis technique, FISH is expected to be applicable to a variety of cells and tissues including interphase and metaphase cell preparations as well as tissue sections and biopsy material. Over the last decade, our laboratories generated a large number of probes and probe sets for the molecular cytogenetic analyses of stem cells derived from different species. These probes and the introduction of spectral imaging bring us close to be able to perform a comprehensive karyotype analysis of single interphase cell nuclei. It should furthermore be possible to couple cytogenetic investigations of the cellular genotype with analysis of gene expression. This report summarizes our technical achievements relevant to stem cell research and outlines plans for future research and developments.     

Fetal cells in the blood of pregnant women: detection and enrichment by fluorescence-activated cell sorting.

Fetal cells, potentially usable for prenatal diagnosis, were sorted from maternal blood samples taken as early as 15 weeks of gestation. Immunogenetic and cytogenic criteria established the fetal origin of the observed cells: Y-chromatin-containing (male) cells were detected in the sorted sample if and only if the newborn proved to be male and carried cell-surface antigens detected by the fluorescent-labeled antibody used for sorting with the fluorescence-activated cell sorter.     

建立十二色荧光原位杂交技术鉴定食管癌KYSE450细胞系的核型

目的:应用12色荧光原位杂交技术(multicolor fluorescence in situ hybridization,M-FISH)鉴定食管癌细胞系KYSE450的染色体畸变．方法:采用DOP-PCR(degenerate oligonucleotide primer-polymerase chain reaction)法混合标记两组多色painting探针,先后两次杂交到相同的KYSE450染色体片,结合反相DAPI显带技术进行核型分析．结果:成功地建立了一种重复的12色荧光原位杂交技术,并鉴定出KYSE450中存在的畸变染色体．该细胞系共有54条染色体,只有13, 21和X号染色体是正常的,其余21条染色体均表现异常．1,2,3,5,6,8,9,14,15,16和17号染色体部分区带增益,4和18号染色体部分区带缺失．7,11,12和19号染色体同时存在区带增益和其它部分区带缺失．1,2,3,4,5,6,7,8,9, 11,12,14,15,16,17,18和19号染色体显示有易位．22号染色体丢失1条,未检测到10,20,Y 染色体成分．结论:12色荧光原位杂交可用于鉴定肿瘤中复杂的染色体异常．KYSE450存在较多与原发性食管鳞癌一致的染色体改变．     

Cholecystokinin cells purified by fluorescence-activated cell sorting respond to monitor peptide with an increase in intracellular calcium.

Cholecystokinin (CCK) is secreted from specific enteroendocrine cells of the upper small intestine upon ingestion of a meal. In addition to nutrients, endogenously produced factors appear to act within the gut lumen to stimulate CCK release. One such factor is a trypsin-sensitive CCK-releasing peptide found in pancreatic juice, known as monitor peptide. This peptide is active within the intestinal lumen and is hypothesized to stimulate CCK secretion by interacting directly with the CCK cell. We have found that monitor peptide releases CCK from isolated rat intestinal mucosal cells and that this effect is dependent upon extracellular calcium. In the present study, we used monitor peptide as a tool for isolating CCK cells from a population of small intestinal mucosal cells. Dispersed rat intestinal mucosal cells were loaded with the calcium-sensitive fluorochrome Indo-1, and CCK secretory cells were identified spectrofluorometrically by their change in fluorescence when stimulated with monitor peptide. Cells demonstrating a change in their emission fluorescence ratio were sorted using a fluorescence-activated cell sorter. More than 90% of the sorted cells stained positively for CCK with immunohistochemical staining. Furthermore, sorted cells secreted CCK when stimulated with membrane-depolarizing concentrations of potassium chloride, dibutyryl cAMP, calcium ionophore, and monitor peptide. These findings indicate that functional intestinal CCK cells can be highly enriched using fluorescence-activated cell sorting. Furthermore, monitor peptide appears to interact directly with CCK cells to signal CCK release through an increase in intracellular calcium.     

Double-staining chromogenic in situ hybridization as a useful alternative to split-signal fluorescence in situ hybridization in lymphoma diagnostics

Background

Malignant lymphomas are classified based on morphology, immunophenotype, genetics and clinical features. The pathological diagnosis is generally considered difficult and prone to mistakes. Since non-random chromosomal translocations are specifically involved in specific entities, their detection is an important adjunct for increasing the reliability of the diagnosis. Recently, split-signal fluorescence in situ hybridization has become available as a robust method to detect chromosomal breaks in paraffin-embedded formalin-fixed tissues. A bright field approach would bring this technology within the reach of every pathology laboratory.

Design and Methods

Our study was initiated to determine the consistency between chromogenic in situ hybridization and fluorescence in situ hybridization, both using split-signal probes developed for the detection of chromosomal breaks. Five hundred and forty cases of 11 lymphoma entities and reactive, benign lymphoid tissues, collected from eight different pathology laboratories, placed on 15 fluorescence in situ hybridization pre-stained tissue microarray slides, were double stained for the chromogenic hybridization. For each core morphology and actual signal were compared to the original fluorescence hybridization results. In addition, hematoxylin background staining intensity and signal intensity of the double-staining chromogenic in situ hybridization procedure were analyzed.

Results

With respect to the presence or absence of chromosomal breaks, 97% concordance was found between the results of the two techniques. Hematoxylin background staining intensity and signal intensity were found to correspond. The overall morphology after double-staining chromogenic in situ hybridization had decreased compared to the initial morphology scored after split-signal fluorescence in situ hybridization staining.

Conclusions

We conclude that double-staining chromogenic in situ hybridization is equally reliable as fluorescence in situ hybridization in detecting chromosomal breaks in lymphoid tissue. Although differences in morphology, hematoxylin staining and chromogenic signal intensity vary between the tumor entities none of the entities appeared more easy or difficult to score.     

荧光原位杂交技术在支气管肺癌中的临床应用

荧光原位杂交技术是近十多年来发展起来的一种分子细胞遗传学技术,其主要是应用荧光物质通过核酸探针杂交原理在核中或染色体上显示DNA序列的位置,在中期及间期细胞均可检测到DNA序列及其变化。染色体的不稳定性是肺癌发生过程的重要阶段,在不同的组织病理类型及分期中均有不同的表现。主要表现为染色体的数目或结构异常,在分子水平上则表现为DNA片段的扩增、缺失、碱基改变等。应用原位荧光杂交技术对肺癌组织细胞进行检测,有助于肺癌的早期诊断,同时对于判断治疗效果、预后及有无复发等均有辅助作用。     

Characterization of pancreatic stem cells derived from adult human pancreas ducts by fluorescence activated cell sorting

AIM: To isolate putative pancreatic stem cells (PSCs) from human adult tissues of pancreas duct using serum-free, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability ofβ-cell differentiation in these PSCs were evaluated as well. METHODS: By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The Matrigel?was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting (FACS) was used to detect the phenotypic markers of putative PSCs. RESULTS: A monolayer of spindle-like cells was culti vated. The putative PSCs expressed pdx-1 and nestin. They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29, CD44, CD49, CD50, CD51, CD62E, PDGFR-a, CD73 (SH2), CD81, CD105(SH3). CONCLUSION: In this study, we successfully isolated PSCs from adult human pancreatic duct by using serum-free medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus.     

Deletion of chromosome band 13q14 as detected by fluorescence in situ hybridization is a prognostic factor in patients with multiple myeloma who are receiving allogeneic dose-reduced stem cell transplantation

We investigated in a retrospective multicenter study the impact of chromosome arm 13q deletion (13q-) as detected by fluorescence in situ hybridization (FISH) on outcome after dose-reduced allografting in patients with multiple myeloma. In 68 of 140 patients, data on chromosome 13q status were available. Most patients included had advanced myeloma. At 2 years, patients with 13q deletion (n = 31) had a shorter event-free (18% vs 42%; P =.05) and overall survival (18% vs 67%; P =.03) than patients without 13q- (n = 37). Patients with 13q- experienced a higher relapse rate (77% vs 44%; P <.001) but a similar incidence of transplantation-related mortality at one year (24% vs 18%). In a multivariate analysis, 13q- remained a significant risk factor for a higher relapse rate (hazard ratio [HR], 3.28; 95% confidence interval [CI], 1.31-8.24; P =.01) and a shorter event-free survival (HR, 1.94; 95% CI, 1.03-3.67; P =.04). Concerning overall survival, 2 or more cycles of prior high-dose chemotherapy were associated with a significantly higher probability of death (HR, 2.48; 95% CI, 1.19-5.17; P =.02), while patients with deletion 13q had a nearly 2 times higher risk of death (HR, 1.94; 95% CI, 0.95-3.98; P =.07) after dose-reduced allogeneic stem cell transplantation.     

N-myc amplification at chromosome band 1p32 in neuroblastoma cells as investigated by in situ hybridization

Summary Chromosome deletion at the short arm of one chromosome 1 (1p32)—the most common aberration in neuroblastoma cells—was found to be combined with the generation of a homogeneously staining region at this specific site in a newly established neuroblastoma cell line (GI-LI-N) from a stage IV neuroblastoma. By in situ hybridization this homogeneously staining region was shown to contain multiple copies of the proto-oncogene N-myc. This 30-fold oncogene amplification was confirmed by Southern-blot and DNA-dot-blot analyses. In two additional cell lines from children with stage IV neuroblastoma (GI-ME-N and GI-CA-N) N-myc amplification was not detected. Chromosome 1, however, was involved in a structural rearrangement in one cell line (GI-ME-N).This study was supported by the Deutsche Forschungsgemeinschaft (SFB 215-A7)Recipient of a fellowship within the Italian-German agreement on Collaborative Cancer Research in Pediatric OncologySupported by the Deutsche Forschungsgemeinschaft (SFB 103-C11)     

Age-dependent accumulation of recombinant cells in the mouse pancreas revealed by in situ fluorescence imaging

Mitotic homologous recombination (HR) is critical for the repair of double-strand breaks, and conditions that stimulate HR are associated with an increased risk of deleterious sequence rearrangements that can promote cancer. Because of the difficulty of assessing HR in mammals, little is known about HR activity in mammalian tissues or about the effects of cancer risk factors on HR in vivo. To study HR in vivo, we have used fluorescent yellow direct repeat mice, in which an HR event at a transgene yields a fluorescent phenotype. Results show that HR is an active pathway in the pancreas throughout life, that HR is induced in vivo by exposure to a cancer chemotherapeutic agent, and that recombinant cells accumulate with age in pancreatic tissue. Furthermore, we developed an in situ imaging approach that reveals an increase in both the frequency and the sizes of isolated recombinant cell clusters with age, indicating that both de novo recombination events and clonal expansion contribute to the accumulation of recombinant cells with age. This work demonstrates that aging and exposure to a cancer chemotherapeutic agent increase the frequency of recombinant cells in the pancreas, and it also provides a rapid method for revealing additional factors that modulate HR and clonal expansion in vivo.     

Clonal proliferation in vitro of individual murine and human hemopoietic cells after fluorescence-activated cell sorting

A modification of the fluorescence-activated cell sorter (FACS) was used to rapidly and reliably study the clonal proliferation of single hemopoietic cells. Murine FDC-P1 and human cord blood progenitor cells were examined for their ability to proliferate from single cells in 96-well microtiter plates containing agar medium and appropriate stimuli. FACS-sorted FDC-P1 single cells formed colonies in 345 out of 558 wells (62%), which compared favorably with control cultures (53%) and micromanipulated single cells (55%). Similarly, the frequency and type of day-14 colonies arising from cord blood progenitor cells when sorted as single cells by the FACS compared favorably with those grown from micromanipulated single cells or in control cultures.     

Quantitative detection of lung cancer cells by fluorescence in situ hybridization: comparison with conventional cytology

STUDY OBJECTIVE: The aim of this study was to clarify whether fluorescence in situ hybridization (FISH) can diagnose lung cancer in various clinical specimens in comparison with conventional cytology. DESIGN: Prospective study. SETTING: University hospital in a metropolitan area. PATIENTS: Fifty consecutive patients with abnormal chest radiography or CT scan findings were enrolled. The patients included 32 men and 18 women, with an average age of 64 years. The final definitive diagnosis was made by histologic examination, as follows: 38 primary lung cancers (24 adenocarcinomas, 8 squamous cell carcinomas, 2 large cell carcinomas, and 4 small cell carcinomas); 1 metastatic renal cell carcinoma; and 11 benign lesions. METHODS: Four types of clinical specimens were analyzed. Cells obtained by transbronchial brushing and transbronchial fine-needle aspiration using a fiberoptic bronchoscope under fluoroscopy, CT scan-guided percutaneous needle biopsy, and bronchial washings. On every examination, duplicate slides were made for analyses of conventional cytology and FISH. RESULTS: Classifications according to conventional cytology were as follows: class I, 4 patients; class II, 15 patients; class IIIa, 3 patients; class IIIb, 5 patients; and class V, 23 patients. A classification higher than class IIIb was considered to be positive for cancer. For cytology, we found no false-positive cases and 11 false-negative cases. The specificity was 100%, and the sensitivity was 71.8%. By FISH, 34 cases showed aberrant copy numbers in either chromosome 3 or 17. We found no false-positive cases and five false-negative cases. The specificity was 100%, and the sensitivity was 87.1%. CONCLUSION: The ability of FISH to detect aneusomic lung cancer cells is superior to conventional cytology for the diagnosis of lung cancer.     

间期荧光原位杂交技术检测骨髓增生异常综合征-7/7q-染色体异常的价值

目的探讨应用间期荧光原位杂交（FISH）技术检测7号染色体/7号染色体长臂缺失（-7/7q-）异常在骨髓增生异常综合征（MDS）中的价值。方法采用常规细胞遗传学（CC）和间期FISH检测技术对72例MDS患者和8例正常对照者的骨髓细胞进行分析,比较CC和FISH检测-7/7q-异常的情况。结果 72例MDS中,12例CC检测阳性,发生率16.7%。间期FISH检测24例阳性,发生率33.3%。两种方法检出率有统计学差异（P〈0.05）。结论间期FISH技术敏感性高于CC,并能发现和纠正CC分析中的漏检异常。