Analysis of genotype and phenotype on the same interphase or mitotic cell. A manual of MAC (morphology antibody chromosomes) methodology

Morphology antibody chromosome technique for determining phenotype and genetic status of the same cell

The morphology antibody chromosome (MAC) technique is a combination of methods that permits analysis of both phenotypic and genetic evaluation on a single interphase or mitotic cell as a basis for lineage analysis of neoplastic and normal cells. This unit describes MAC with sequential phenotypic analysis using antibody and an alkaline phosphatase anti-alkaline phosphatase (APAAP) complex and genotypic analysis using in situ hybridization with either enzymatic or fluorescence detection. Alternate methods for phenotypic analysis are also described, which include the use of horseradish peroxidase-conjugated antibodies, fluorochrome-conjugated antibodies, May-Grunwald-Giemsa cytochemical staining, and Sudan black B cytochemical staining. An additional protocol describes G- and C-banding as alternatives to in situ hybridization (ISH) for genotyping MAC specimens. Support protocols describe methods for preparing specimens, cytospin preparations, in situ cultures, paraffin-embedded or cryostat sections, and blood and bone marrow smears. Also described is a procedure for chromosome painting of previously GTG-banded slides. An additional protocol is included for FISH analysis on sorted hematopoietic stem cells and its application in the detection of leukemic stem cells. For overcoming the drawbacks of scarcity and variability from case to case of malignant plasma cells in multiple myeloma FISH analyses, a protocol is included for the enrichment of plasma cells by immunomagnetic beads.

Combined immunofluorescence and FISH: new prospects for tumor cell detection/identification

Fluorescence-microscope based methods are presented that allow automatic selection and quantification of immunophenotyped cells and sequential FISH analysis to facilitate molecular cytogenetic analysis of single cells and very small cell populations. The protocols in this unit are particularly useful for studying the biological and genetic makeup of disseminated tumor cells or other rare cells.

Morphology antibody chromosome technique for determining phenotype and genotype of the same cell

The morphology antibody chromosome (MAC) technique is a powerful combination of methods that permits analysis of both phenotype and genotype on a single interphase or mitotic cell as a basis for lineage analysis of neoplastic and normal cells. This unit describes MAC with sequential phenotypic analysis using antibody and an alkaline phosphatase anti-alkaline phosphatase (APAAP) complex and genotypic analysis using in situ hybridization with either enzymatic or fluorescence detection. Alternate methods for phenotypic analysis are also described, which include the use of horseradish peroxidase-conjugated antibodies, fluorochrome-conjugated antibodies, May-Grunwald-Giemsa cytochemical staining, and Sudan black B cytochemical staining. An additional protocol describes G- and C-banding as alternatives to in situ hybridization (ISH) for genotyping MAC specimens. Support protocols describe methods for preparing specimenscytospin preparations, in situ cultures, paraffin-embedded or cryostat sections, and blood and bone marrow smears. Basic Protocol 2 describes a procedure for chromosome painting of previously GTG-banded slides.

Genomic aberrations in mucinous tubular and spindle cell renal cell carcinomas

Mucinous tubular and spindle cell carcinoma of the kidney is a new diagnostic entity. We present the pathologic and genomic characteristics of three such low-malignant tumors. Two of the tumors were found in women aged 19 and 52 years, the third tumor was found in an 80-year-old man, and the tumor stages were pT2N0MX, pT2NXMX, and pT1NXMX, respectively. Findings by immunohistochemistry were similar but not identical for the three cases; markers for both proximal and distal parts of the nephron were expressed in each tumor, a finding that is in agreement with data from previous studies. The Ki-67-labeling index was below 5 in all three cases. Two of the tumors were predominantly hypodiploid (DNA-indexes 0.77 and 0.80), whereas the third tumor was hypertriploid (1.57) as measured by DNA-image cytometry. From the latter tumor live cells were available making it possible to establish its karyotype: 62-70,XXX,+del(X)(q11),-1,+2,+4,-5,-6,+7,-8,-9,-10,-11,+12,-13,-14,-15,+16,+17,+18,-19,+20,+21,-22[cp15]. Interphase fluorescence in situ hybridization analyses with centromere-specific probes for chromosomes 1, 3, 4, 6, 7, 9, 10, 17, 18, 20, and X showed that the two hypodiploid tumors had disomic and monosomic chromosome populations, whereas the karyotyped, near-triploid tumor was dominated by trisomic chromosome populations. Comparative genomic hybridization analysis was normal for the karyotyped tumor but abnormal for the two others. We conclude that multiple numerical chromosome aberrations may be a feature of mucinous tubular and spindle cell carcinomas of the kidney, but beyond that no clear-cut karyotypic aberration pattern is so far discernible.

Methods for isolating circulating epithelial cells and criteria for their classification as carcinoma cells

Novel assay methods developed for the isolation and characterization of circulating tumor cells (CTC) of epithelial origin offer the potential of markers for the non-invasive gathering of clinical information relevant to the diagnosis, evolution and treatment of carcinoma. Of the numerous techniques currently used to analyze CTC, slide-based assays are perhaps the most common. While traditional combined immunocytochemical/brightfield microscopy systems continue to be the most frequently employed, fluorescence-based analysis is gaining in importance. This is partly because fluorescence microscopy analysis of slide-mounted CTC can provide simultaneously cytogenetic as well as morphologic and multiple phenotypic information. In particular, fluorescence microscopy analysis of slide-mounted CTC can accurately determine genetic changes at the chromosomal level in patients with recurrent disease. More importantly, by identifying genetic aberrations in CTC, it becomes possible to choose those patients most likely to benefit from a given treatment. The potential of this technique has already been demonstrated by employing fluorescence in situ hybridization (FISH) methods to measure expression of the HER2/neu gene in tissue from patients with breast carcinoma for the specific purpose of identifying those patients most likely to respond to Trastuzumab targeted therapy. Here, we review the major methodologies used in the preparation and analysis of the slide-based assays.

Molecular cytogenetic characterization of tenosynovial giant cell tumors

Tenosynovial giant cell tumor (TSGCT) is a disease of disputed etiology and pathogenesis. Some investigations indicate a neoplastic origin of the tumors; others indicate that they are polyclonal and inflammatory. The cytogenetic and molecular genetic features of TSGCTs are largely unknown, as only some 20 localized and 30 diffuse tumors with cytogenetic aberrations have been reported. The most common karyotypic aberrations have been trisomy for chromosomes 5 and 7 and translocations involving chromosomal area 1p11-13. We decided to screen the genomes of TSGCTs by comparative genomic hybridization (CGH) to perform interphase fluorescence in situ hybridization (IP-FISH), looking for numerical aberrations of chromosomes 1, 5, and 7, and to analyze the tumors for microsatellite instability. Except for two diffuse TSGCTs that came fresh to us, and which, by karyotyping, exhibited t(1;22)(p13;q12) and a t(1;1)(q21;p11) and +7, respectively, all studies had to be performed on formalin-fixed, paraffin-embedded material. DNA was extracted from 51 localized and nine diffuse TSGCTs. CGH was successful for 24 tumors, but none of them showed copy number changes. The IP-FISH studies showed trisomy 7 in 56% of the tumors (15/27), whereas chromosomes 1 and 5 seemed to be disomic in all TSGCTs. All informative tumors were wild-type by microsatellite instability analysis.

Chromosome abnormalities in juxtaglomerular cell tumors

BACKGROUND

Juxtaglomerular cell tumors (JGCT; also known as reninomas) are considered benign tumors of the kidney, although there have been reports of both malignant behavior and a JGCT-related death. The clinicopathologic features of these rare tumors are well established, whereas nothing is known about their cytogenetic characteristics.

METHODS

The authors reported the first karyotype of a JGCT and also performed comparative genomic hybridization (CGH) and interphase fluorescence in situ hybridization (IP-FISH) analyses on the above-mentioned tumor as well as on another JGCT from which live cells were not available for karyotyping. Both tumors were also examined by electron microscopy and immunohistochemistry.

RESULTS

The karyotype was 57 approximately 64,XX,-X,-1,-4,-6,-9,+10,-11,-13,-14, -15,+20,-22[cp10]/60 approximately 61,idem, add(19)(p13)[cp2]/46,XX[3]. The IP-FISH results were in accordance with the karyotypic findings for the first tumor, whereas Tumor 2 was found to be diploid for most investigated chromosomes, except for trisomy for chromosomes 4 and 10 and monosomy for chromosomes 9 and X. By CGH, gain of chromosomes 10 and 20 but no losses were detected for Tumor 1, whereas for Tumor 2, gain of chromosomes 4 and 10 as well as loss of chromosomes 9 and X and most of chromosome arm 11q were found. The immunohistochemical profiles were identical. Both tumors were positive for vimentin and CD34, focally positive for smooth muscle actin, and negative for cytokeratin, CD31, and actin.

CONCLUSIONS

Gain of chromosome 10, as well as loss of chromosomes 9 and X and most of chromosome arm 11q, might be important pathogenetic events in JGCT.

Molecular cytogenetic characterization of desmoid tumors

Desmoid tumors are benign neoplasms of the fibromatosis group. Data on their acquired chromosomal changes are sparse and, therefore, we wanted to ascertain what genomic losses and gains these tumors may have incurred. DNA was extracted from a total of 26 formalin-fixed, paraffin-embedded desmoid tumors followed by comparative genomic hybridization (CGH) and interphase fluorescence in situ hybridization (I-FISH) analyses. Ten of 12 informative tumors were normal by CGH; the two abnormal ones had loss of chromosome 6 and loss of 6q and gain of chromosome 20, respectively. I-FISH analyses with an alpha-satellite probe specific for chromosome 8 of 26 desmoids, including one tumor that by karyotyping had +i(8)(q10), showed no evident abnormalities. An explanation for the relatively high frequency of genomically normal tumors by CGH seen in this study may be sought in the fact that as many as 10 of the 12 informative tumors were abdominal desmoids, a subset of tumors also previously found to exhibit genomic changes only rarely. It is therefore possible that abdominal desmoids might be non-neoplastic tumors or neoplastic tumors with genetic changes too small to be discovered by CGH, whereas desmoid tumors from other locations exhibit detectable genomic changes at a significantly higher frequency.

Fluorescence in situ hybridization BCR/ABL fusion signal rate in interphase nuclei of healthy volunteer donors: a test study for establishing false positive rate

Fluorescence in situ hybridization (FISH) using chromosome-specific DNA probes is rapidly becoming a part of clinical laboratory practice. However, as a relatively new clinical test, it is not yet standardized and for practical reasons each laboratory must establish its own criteria. For this purpose we have evaluated the specificity of a dual-color BCR/ABL translocation probe by establishing the range of BCR/ABL fusion-positive scores in a healthy donor group. The false positive rate (FPR), determined by the percent of FISH BCR/ABL fusion-positive cells found in the specimens of healthy donors, was estimated at 2.3% (mean = 1%-4%). Thus the cut-off value for false positive nuclei was set at 5%.

Effect of dithiocarbamate pesticide zineb and its commercial formulation, azzurro. II. micronucleus induction in immunophenotyped human lymphocytes

The frequency of micronuclei was measured in human peripheral B-lymphocytes and some T-lymphocyte subpopulations exposed in vitro to 1.0-100.0 microg/ml of the dithiocarbamate pesticide zineb and its commercial formulation azzurro. The peripheral mononuclear lymphocytes were stimulated in vitro with phytohemagglutinin after pesticide treatment and B-lymphocytes and the various T-lymphocyte subsets were classified by the MAC (morphology, antibody, chromosomes) method, which allows the immunological identification of different cell lineages. An increased frequency of micronuclei in CD20(+) (P < 0.01), CD3(+) (P < 0.01), and CD8(+) lymphocytes (P < 0.01) was observed only when 25.0 microg/ml of zineb and azzurro were employed. The frequency of micronuclei in treated CD8(+) cells did not differ from treated CD20(+) lymphocytes (P > 0.05). Lower concentrations of pesticides did not increase the frequency of micronuclei from that observed in control cultures. Furthermore, for both zineb and azzurro cytotoxicity was observed at doses higher than 50.0 microg/ml. Significant increases in the proportion of CD20(+) (P < 0.01) and CD8(+) cells (P < 0.01) among mitotic and interphasic lymphocytes from both zineb- and azzurro-treated cultures were observed only when a concentration of 25.0 microg/ml was employed. In contrast, significant decreases in the proportion of CD3(+) (P < 0.01) and CD4(+) cells (P < 0.01) were found for both mitotic and interphasic lymphocytes from zineb- and azzurro-treated cultures. The MAC methodology revealed that among the different lymphocyte subpopulations analyzed (CD20, CD3, CD4, and CD8), the induction of micronuclei by zineb and its commercial formulation azzurro was restricted to CD20(+) B-cells and T-suppressor/cytotoxic CD8(+) lymphocytes.

Detection of fetal trisomy 18 by short-term culture of maternal peripheral blood

OBJECTIVE

We report the prenatal detection by fluorescence in situ hybridization analysis of a male fetus with trisomy 18.

STUDY DESIGN

Total nucleated cells recovered from 7 mL of maternal peripheral blood by means of double-density gradient centrifugation were cultured for 3 days in a devised medium.

RESULTS

Fetal cells with X- and Y-specific signals were detected in all the established cultures, but the yield and purity were higher in the culture from the 1077 Ficoll layer. Cumulatively, 84 fetal cells were recorded by analysis of 5640 cells. The hematopoietic lineages involved in the production of the fetal cells in culture were not assessed. For the cultures established with the 1119 Ficoll layer, the involvement of progenitors or precursors of the erythroid lineage was assumed because postculture sorting was directed toward cells expressing the erythropoietin receptor.

CONCLUSION

We conclude that culturing total nucleated cells from maternal blood is a new procedure that could prove valuable in the detection of the main fetal aneuploidies affecting pregnant populations.

Fluorescence in situ hybridization: molecular probes for diagnosis of pediatric neoplastic diseases

Fluorescence in situ hybridization (FISH) has become an important tool for diagnosing neoplasia in children. With probes designed to identify specific chromosomes and chromosomal regions, FISH is commonly used to detect the specific chromosomal abnormalities associated with hematologic diseases and solid tumors. Variations of FISH currently being investigated, such as comparative genomic hybridization, multicolor FISH, and microchip arrays, will probably result in additional uses of FISH in both research and clinical cytogenetic laboratories. Although FISH has disadvantages when compared with conventional cytogenetics and molecular methods, FISH will continue to be important in analyzing chromosomal abnormalities of tumors in children.

Vinorelbine: cell cycle kinetics and differential sensitivity of human lymphocyte subpopulations

Antiproliferative activity induced by vinorelbine (VRB) was studied in whole blood cultures (WBC) and in lymphocyte subpopulations evaluated by the MAC (morphology-antibody-chromosome) method. In WBC a significant delay in cell cycle kinetics in VRB-treated cultures compared with controls (P < 0.001) was observed. The highest dose (1.0 microg/ml) arrested all cells at the first metaphase. Both WBC and isolated lymphocyte cultures showed a significant increase in the mitotic index (MI) in VRB-treated cultures compared with controls (P < 0.001). Moreover, a significant increase in the MI was found in VRB-treated CD4 cells compared with VRB-treated CD8 (P < 0.01) and B-lymphocytes (P < 0.001).

Detection of genetic alterations in micrometastatic cells in bone marrow of cancer patients by fluorescence in situ hybridization

Detection of micrometastatic tumor cells in bone marrow of cancer patients has been shown to be of prognostic significance. To further characterize these cells, we combined antibody labeling and fluorescence in situ hybridization (FISH). For detection of numerical changes of chromosome 17, nine patients with proven breast cancer whose bone marrow contained epithelial tumor cells were evaluated. Epithelial cells were stained by anticytokeratin antibody. Afterwards FISH was performed using an alpha-satellite probe specific for chromosome 17. In a second series bone marrow epithelial cells of eight patients with breast cancer and of six with prostatic cancer were evaluated for the amplification of HER-2/neu by using a gene-specific DNA probe. In the first series four patients had only single epithelial cells in their bone marrow. Only one single cell showed five hybridization signals, whereas all other single cells showed two or less. Five patients had clusters of epithelial cells in bone marrow with or without additional single cells. One hundred four cells had three or more hybridization signals and 103 of these polysomic cells were located in tumor cell clusters. In the second series we could detect HER-2/neu amplification in bone marrow epithelial tumor cells in two of eight patients with breast cancer but in none of the prostatic cancer patients. These results show that it is possible to detect numerical chromosomal changes and oncogene amplification in bone marrow micrometastatic epithelial cells of cancer patients by combining immunophenotyping and FISH.

Maternal origin of transferrin receptor positive cells in venous blood of pregnant women

We studied the origin of transferrin receptor (CD71) positive cells in blood from seven women pregnant with a male fetus in order to explore if fetal cells could be detected among them. We used a technique that allows direct chromosomal analysis by in situ hybridization on immunologically and morphologically classified cells. Enrichment was performed by magnetic activated cell sorting (miniMACS) using an anti-CD71 monoclonal antibody. The cells were immunophenotyped by alkaline phosphatase anti-alkaline phosphatase immunostaining with the same antibody. The origin of the immunophenotyped cells was studied by in situ hybridization using an X cosmid Y repeat chromosome specific probe cocktail. CD71 positive cells were found in six of the seven women at the range of 4 to 43 in respective samples. Over 90% of the CD71 positive cells were nucleated erythrocytes. None of the detected positive cells were shown to be fetal. Thus, the use of transferrin receptor antigen alone in combination with the miniMACS may not be sufficient for enrichment of fetal cells.

Lymphoid involvement in a patient with acute myeloid leukemia: a direct phenotypic and genotypic study of single cells

Lymphoid involvement in acute myeloid leukemia (AML) was studied using the morphology-antibody-chromosome (MAC) combination technique in one patient. The chromosomal aberration, trisomy 8, was demonstrated in AML blasts, glycophorin A-positive erythroblasts, and CD3- and CD20/22-positive small lymphocytes. This suggests that in this patient even lymphocytes belonged to the leukemic clone.

Chromosome 7 in glioblastoma tissue. Parenchymal vs. endothelial cells

Strong endothelial proliferation is a prominent feature of glioblastomas and sometimes these proliferated areas transform into a malignant component of glioblastoma, resulting in gliosarcomas. It has not been established whether the proliferated endothelial areas are cytogenetically abnormal. To clarify this question, the most common cytogenetic aberration, gain of chromosome 7, was chosen and in situ hybridization was performed on paraffin-embedded tissue sections of three glioblastomas. The purpose was to compare the parenchymal tumor cells and the endothelial cells. The results showed trisomy 7 in only a small amount of endothelial cells (5-8%), whereas 23-38% of parenchymal tumor cells displayed trisomy 7.

Maternal origin of nucleated erythrocytes in peripheral venous blood of pregnant women

We studied the origin of nucleated red blood cells (NRBC) in peripheral venous blood samples from 40 pregnant women carrying a male fetus, using a technique that allows direct chromosomal analysis by in situ hybridisation on immunologically and morphologically classified cells. Samples from ten nulligravid women were studied as controls. NRBC were enriched by negative magnetic activated cell sorting (miniMACS) using anti-CD45 monoclonal antibody. NRBC were detected by alkaline phosphatase anti-alkaline phosphatase immunostaining using a monoclonal anti-glycophorin A antibody. The origin of the NRBC was determined by fluorescence in situ hybridisation using X and Y specific probes. NRBC were found in 37 of the 40 pregnant women at a range of 1 to 230 per 20 ml of venous blood and in 6 of the 10 controls at a range of 1 to 3 per 20 ml of venous blood. All NRBC detected in the pregnant women were evidently of maternal origin, and in the pregnant women the number of NRBC was significantly higher (P < 0.05) than in the controls. Pregnancy per se seems to induce the appearance of maternal NRBC in the circulation, and it cannot therefore be assumed that NRBC isolated from the maternal blood are of fetal origin on the basis of morphology alone. Discrimination of fetal NRBC must occur for prenatal diagnosis of fetal genetic disorders.

FISH analysis on spontaneously arising micronuclei in the ICF syndrome

The ICF syndrome is a rare disorder where patients show undercondensation of the heterochromatic blocks of chromosomes 1, 9, and 16 along with variable immunodeficiency. The undercondensation of the heterochromatic block appears to be restricted to a portion of PHA stimulated T cells. Patients with this syndrome also show an increase in micronuclei formation. We have used dual colour FISH to investigate the chromosomal content of these micronuclei in PHA stimulated peripheral blood cultures, an EBV transformed B cell line, and also micronuclei observed in vivo from peripheral blood smears. Chromosome 1 appears to be present in a higher proportion of micronuclei compared to chromosomes 9 and 16 in both a PHA stimulated culture and an EBV transformed cell line. An 18 centromeric probe, not associated with the ICF syndrome, showed no signal in any of the micronuclei observed. The implications from these observations are that the heterochromatic instability in the ICF syndrome is manifested not only in T but also in B cells and that it is present in vivo.

Lineage involvement and karyotype in a patient with myelodysplasia and blood basophilia

We report a 63-year-old woman with myelodysplastic syndrome (MDS), refractory anaemia with ring sideroblasts (RARS), and blood basophilia with pathological forms. Karyotype analysis revealed a complex rearrangement: 46,XX,del(3)(p13p25),del(5)(q13q33),der(16)t(1;16) (p13;q12)/47,idem,add(20)(?p11)/49,idem, + add(1)(q32),add(20)(?p11), + mar/46,XX. Karyotype, immunophenotype and in situ hybridization studies by the MAC (morphology antibody chromosomes) combination technique revealed the chromosomal abnormality in granulocytic/monocytic and erythrocytic metaphase cells. Also mature basophils and other granulocytes were involved with the abnormality. We suggest that our patient with the MDS has a stem cell disorder affecting all myeloid cell lineages and that basophilia constitutes a part of the malignant process.

Prenatal sex determination by in situ hybridization on fetal nucleated cells in maternal whole venous blood

Our aim was to evaluate whether the sex of a fetus could be determined in maternal whole venous blood by in situ hybridization without enrichment of fetal cells. This procedure is virtually without risks to the fetus or the mother. Blood samples were obtained from 59 women at different stages of pregnancy. Twenty preparations were discarded because they were technically unfit for in situ hybridization. Of the remaining 39 pregnant women, 18 had a male fetus, one had male twins, and 20 had a female fetus. Y-positive cells were detected in 12 of the 19 pregnancies with male fetuses and in two of the 20 pregnancies with a female fetus. The frequencies of cells with Y-signals ranged from 1 in 100,000 to 1 in 639. Our results show that fetal cells in maternal blood cannot be reliably used for prenatal diagnosis without prior enrichment of fetal cells.