Loss of Y chromosome in bilharzial bladder cancer.

Bilharzial bladder cancer is the most common malignant neoplasm in Egypt, also occurring with a high incidence in other regions of the Middle East and East Africa. In a previous study, using centromere probes specific for chromosomes 3, 4, 7-11, 16, and 17, we demonstrated that monosomy of chromosome 9 (48.4%), and numerical aberrations of chromosome 17 (19.4%) were the most common observed imbalances. The present study extends the establishment of the baseline cytogenetic profile of this type of malignancy. Interphase cytogenetics by fluorescence in situ hybridization with the use of a panel of centromere-associated DNA probes for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, X, and Y was performed on paraffin-embedded bladder specimens from 25 Egyptian patients affected with bilharzial bladder cancer. No numerical aberrations were detected in the 25 cases for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, and X. However, loss of chromosome Y was observed in 7 of the 17 male cases studied (41.2%). No significant correlation was observed between loss of the Y chromosome and any of the different clinicopathologic characteristics of these cases. These data suggest that loss of the Y chromosome is the second frequent event that can occur in bilharzial bladder cancer. A molecular genetic model of bilharzial bladder cancer is evolving.

Chromosomal aberrations in Bilharzial bladder cancer as detected by fluorescence in situ hybridization.

Cancer of the bladder is a frequent malignancy in Egypt and other developing countries in which bladder infection with the parasite Schistosoma haematobium is common. Several epidemiological, histopathological, and clinical characteristics of cancer of the Bilharzial bladder suggest that it is distinct from bladder cancer seen in other places in the world. No numerical aberrations of chromosomes that might be specific for Bilharzial bladder carcinoma have been established. In this study, we used fluorescence in situ hybridization (FISH) with centromere-specific probes for chromosomes 3, 4, 7, 8, 9, 10, 11, 16, and 17 to detect numerical aberrations of these chromosomes in frozen-stored samples of 31 Egyptian patients affected with Bilharzial carcinoma. Among 5 types of chromosomes examined, imbalance was observed; the most common imbalance was a loss of chromosome 9 (48.4%), with numerical aberration of chromosome 17 being the second most-frequent anomaly (19.4%). The presence of such anomalies, especially losses of chromosome 9, are associated with a younger age group of patients, as well as with a lower grade tumor and negative pelvic node involvement by the disease. Fluorescence in situ hybridization analysis thus proved to be a useful method for detecting numerical aberrations of individual chromosomes, with application to touch preparations of frozen-stored tissue having the advantage of exact sampling of cancer foci. This result also suggests that the mechanism of genetic progression of bladder cancer is independent of its etiology.

Specific numerical chromosomal aberrations induced by adriamycin.

Fluorescence in situ hybridization with 7, 17, X, and Y chromosome-specific DNA probe was used to investigate the ability of Adriamycin (AM) to induce aneuploidy in interphase human lymphocytes. The reliability of the probes was tested by hybridization to metaphases and interphase nuclei of untreated normal lymphocytes. Two signals were scored in over 87% of the analyzed nuclei with chromosome 7 and 17 probes, whereas one signal was recorded in over 86% of the nuclei with chromosomes X and Y. The same conditions and probe concentrations were used for hybridizing the four probes to interphase nuclei of AM-treated and untreated lymphocytes, cultured from healthy individuals and cancer patients. AM was found to induce significant increases of trisomy 7 and 17 in lymphocytes cultured from healthy individuals and cancer patients, where the interphase nuclei showed three spots in over 70% and 72% of the cells, respectively. Only 6% of interphase nuclei of untreated cells cultured from healthy individuals and cancer patients showed three spots. No significant increase in X or Y aneuploidy was induced by exposure to AM.

Human type I cytokeratin genes are a compact cluster.

A YAC clone (211F11) containing approximately 0.5 Mb of human DNA was isolated from a human genomic library by PCR-based screening with cytokeratin (KRT) 13-specific primers. The YAC clone was mapped by FISH to the long arm of chromosome 17 (17q12-->q21), a region to which several other type I KRT genes had been mapped previously. We now show by Southern blot hybridization and PFGE analyses that KRT13, 14, 15, and 16 are all contained within YAC clone 211F11. Long-range restriction mapping analysis of clone 211F11 and of two smaller YAC clones that were also isolated with KRT13-specific primers, suggests that KRT13, 14, 15, 16 and their linked type I genes KRT17 and 19, are contained in less than 150 kb of genomic DNA. According to our reconstruction it then appears that at least six type I KRT genes are arranged in a highly compact cluster. The three YACs reported in this study represent a new tool to dissect the molecular structure of the locus of the human type I KRT genes.

Structure and chromosomal localization of the human gene of the phosphotyrosyl phosphatase activator (PTPA) of protein phosphatase 2A.

The PTPA gene encodes a specific phosphotyrosyl phosphatase activator of the dimeric form of protein phosphatase 2A. PTPA, cloned from human genomic libraries, is encoded by one single-copy gene, composed of 10 exons and 9 introns with a total length of about 60 kb. The transcription start site was determined, and the 5' flanking sequence was analyzed for its potential as a promotor. This region lacks a TATA sequence in the appropriate position relative to the transcription start, is very GC-rich, and contains upstream of the transcription start four Sp1 sites, a feature common to many TATA-less promotors. Based on the homology with DNA binding consensus sequences of transcription factors, we identified in this promotor region several putative DNA binding sites for transcription factors, such as NF-kappa B, Myb, Ets-1, Myc, and ATF. Transfection experiments with a construct containing the PTPA promotor region inserted 5' of a luciferase reporter gene revealed that the 5' flanking sequence of the PTPA gene indeed displayed promotor activity that seems to be cell-line dependent. By fluorescence in situ hybridization and G-banding, the PTPA gene was localized to the 9q34 region. The PTPA gene is positioned centromeric of c-abl in a region embracing several genes implicated in oncogenesis.

Some desmoid tumors are characterized by trisomy 8.

Ten desmoid tumors were examined by chromosome banding analysis and by in situ hybridization on short-term cultures and frozen sections. Trisomy 8 was detected in four out of ten tumors, of which only one had shown trisomy 8 by karyotype analysis. Since trisomy 8 has been reported in superficial fibromatoses, which are clinically distinct but histologically similar to desmoid tumors, the occurrence of trisomy 8 in both may be a further indication of a close relationship.

Chromosome abnormalities in benign prostatic hyperplasia.

We combined conventional cytogenetic analysis and fluorescence in situ hybridization of short-term cultures of 28 samples from benign prostatic hyperplasia. Loss of the Y chromosome was the most common chromosome change, followed by trisomy 7. Trisomy 7, however, may be unrelated to the origin of benign prostate hyperplasia, in which the only and not very specific change seems to be the loss of the Y chromosome.

Competitive in situ hybridization in a mediastinal germ cell tumor.

We performed competitive in situ hybridization in a mediastinal germ cell tumor to identify chromosome 12 aberration(s). DNA from a mouse-human somatic hybrid cell line, containing an i(12p) as unique human material, was labeled and used as a probe. Our results confirm that the chromosome marker, observed in mediastinal germ cell tumor and cytogenetically identified as i(12p), is a true isochromosome of the short arm of chromosome 12.

Studies on tissue cholinesterase in experimental trichinosis in albino rat. 2 effects of treatment with Mintezol and 5-fluorouracil-Endoxan.

The changes in cholinesterase (ChE) activity was studied in different tissues of normal and 60 days T. spiralis infected albino rats following treatment with Mintezol (5 mg/rat/day, for 5 days) and 5-fluorouracil-Endoxan (500 mg/rat/day--100 mg/rat/day, for 5 days). In normal rats, administration of either Mintezol or 5-fluorouracil-Endoxan provoked a general decrease in the ChE activity of the various rat tissues. Treatment of 60 days T. spiralis infected rats with Mintezol increased markedly the ChE activity of the brain, liver, gastrocnemius muscle and serum. Meanwhile treatment with 5-fluorouracil-Endoxan decreased the enzyme activity in the selected rat tissues. It can be concluded that treatment with Mintezol and 5-fluorouracil-Endoxan in trichinellosis represents a certain danger. This danger results from general inhibition of ChE activity which may cause accumulation of acetylcholine.

Studies on tissue cholinesterase in experimental trichinosis in albino rat. 1. Effect of T. spiralis infection.

Adult male albino rats were orally infected with Trichinella spiralis (T. spiralis) larvae (400 larvae/rat). The cholinesterase (ChE) activity was then determined in the serum, brain, spinal cord, liver, stomach, intestine, heart, diaphragm and gastrocnemius muscle of the infected rats at different time intervals (15, 30, 45, 60 and 90 days) after infection. The enzyme activity was inhibited at all the time intervals in the brain, liver, heart and diaphragm while it increased progressively in the serum. In the spinal cord the ChE activity was inhibited at 15, 30 and 45 days postinfection but was markedly increased thereafter. In the intestine, stomach and gastrocnemius muscle the enzyme activity was generally increased. These alterations in ChE activity may be due to the stress effect due to the presence of the larvae in the tissues and/or the toxic effect or their metabolites.

The gene for tissue inhibitor of metalloproteinases-2 is localized on human chromosome arm 17q25.

Tissue inhibitor of metalloproteinases-2 (TIMP2) is a natural inhibitor of several proteinases that are involved in the degradation of the extracellular matrix. By means of somatic cell hybrids segregating human chromosomes, the gene encoding this inhibitor was assigned to human chromosome 17. Fluorescence in situ hybridization confirmed this assignment and allowed mapping of the gene to the terminal region (17q25) of the chromosome.

Trisomy 7 and trisomy 10 characterize subpopulations of tumor-infiltrating lymphocytes in kidney tumors and in the surrounding kidney tissue.

We performed conventional cytogenetic analysis and fluorescence in situ hybridization in short-term cultures of normal and neoplastic kidney tissues. Cell populations carrying an extra chromosome 7 or an extra chromosome 10 as the only chromosome change could be identified in kidney tumors, mostly renal cell carcinomas, and in the surrounding kidney tissue, but not in nonneoplastic kidneys. To identify the type of cells displaying these aneuploidies, we performed in situ hybridization (ISH) with probes specific for the centromeric region of chromosomes 7 and 10 on frozen kidney tissue sections. Trisomy 7 and trisomy 10 were restricted to infiltrating inflammatory cells in the tumor as well as in the surrounding tissue. Trisomy 7 and trisomy 10 were also found in subpopulations of peripheral blood T cells of cancer patients and of normal individuals, as well as in the thymus of five normal fetuses (21-29 weeks), but not in noninvaded reactive lymph node sections of patients without malignancy. When lymphocytes were enriched from kidney tumors and surrounding tissue by either Ficoll/Hypaque density gradient or immunomagnetic selection with anti-CD3, anti-CD4, or anti-CD8 monoclonal antibodies, it was confirmed that they contained a high percentage of trisomy 7 and trisomy 10 cells. Further proof for T-lymphocyte origin of the trisomy 7 and trisomy 10 cells was obtained by simultaneous staining of lymphocytes isolated from tumor tissue with anti-CD3, anti-CD4, and anti-CD8 monoclonal antibodies and ISH. We conclude that trisomy 7 and trisomy 10, found in renal carcinomas and surrounding kidney tissue, characterize subpopulations of tumor-infiltrating lymphocytes. The biologic significance of this phenomenon is unknown and requires further investigation.

Involvement of 19q13 in follicular thyroid adenoma.

Cytogenetic investigation of a follicular thyroid adenoma from a 31-year-old woman showed a t(16;19)(q12;q13), as the sole chromosome abnormality. As five more cases with 19q13 involvement have been described, we suggest that the terminal region of the long arm of chromosome 19 is important for the development of follicular thyroid adenoma.

The gene for the alpha 4 subunit of the VLA-4 integrin maps to chromosome 2Q31-32.

The VLA-4 integrin (CD49d/CD29), initially discovered on lymphoid cells, is actually known to be highly expressed on T cells, B cells, monocytes, and derived cell lines. Unlike other VLA integrins, mainly involved in cell-matrix adhesive interactions, VLA-4 has also been implicated in several cellular interactions. Based on the published alpha 4 cDNA sequence, a 1,142-bp alpha 4 cDNA fragment was amplified using the polymerase chain reaction. This fragment was used to isolate three overlapping genomic clones from a phage library. By Southern analysis with the cDNA probe, and using the polymerase chain reaction on DNA isolated from a panel of human/mouse somatic cell hybrids, the alpha 4 gene was mapped to chromosome 2. Fluorescence in situ hybridization confirmed this assignment and allowed a more precise mapping to chromosome 2q31-32.

A variant (2;13) translocation in rhabdomyosarcoma.

Cytogenetic analysis of a right buttock mass from a 5-year-old boy showed translocation between an inverted chromosome 1 and a chromosome 13 as the sole cytogenetic abnormality. The breakpoint 13q14 appears to be the same as in previously reported cases of rhabdomyosarcoma (mostly of the alveolar type), but does not show involvement of 2q37. We suggest that this translocation may be a variant of the classical t(2;13)(q37;q14) found in rhabdomyosarcoma.

Localization of the gene encoding the alpha 2 subunit of the human VLA-2 receptor to chromosome 5q23-31.

The alpha 2 subunit of the VLA-2 receptor (CD49B) was mapped to human chromosome 5 by several independent approaches. First, the expression of the alpha 2 subunit at the protein level was investigated in a panel of human-mouse hybrid cell lines. Cell surface expression was detected by indirect immunofluorescence with monoclonal anti-alpha 2 antibody 12F1. Intracellular alpha 2 antigen was detected by immunostaining of whole cell extracts or of immunoprecipitated 12F1 antigen with the monoclonal antibodies 3H8 and 5C5. Second, the presence of human genomic alpha 2 sequences in the panel of human-mouse hybrids was detected by PCR, using primers derived from the published alpha 2 cDNA sequence. The specificity of the amplification product was shown by direct sequencing. The results of the PCR study were confirmed by amplifying a CD14 gene fragment, known to map to chromosome 5. Finally, in situ hybridization with a 3H-labeled 1040-bp cDNA probe, also obtained by PCR, confirmed and refined the localization of CD49B on chromosome 5 at q23-31.

Human and rat chromosomal localization of two genes for 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase by analysis of somatic cell hybrids and in situ hybridization.

Two genes encoding 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase were localized in human and rat chromosomes. PFKFB1 (previously PFRX), which encodes the liver and muscle isozymes, was assigned to Xq22-q31 in the rat and to Xq27-q28 in the human by in situ hybridization using probes generated by the polymerase chain reaction. PFKFB2, which encodes the heart isozyme of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, was assigned to chromosome 13 in the rat and to chromosome 1 in the human by hybridization of DNA from somatic cell hybrids. By in situ hybridization, this gene was localized to the regions 13q24-25 in the rat and 1q31 in the human.