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PubMed1976

"Non-condensed" and "condensed" chromain in transitional cell carcinoma of the human urinary bladder.

The area and content of "non-condensed" and "condensed" chromatin in smeared Feulgen-stained malignant urothelial cells were determined by means of scanning-cytophotometry. The results were compared with those from similar measurements of benign human transitional epithelial cells. There was no difference between the relative area and content of "non-condensed" and "condensed" chromatin in cancer nuclei and normal urothelial nuclei as far as nuclei of the same size and ploidy class were considered. Within the same ploidy class the relative area and content of "non-condensed" chromatin increased with increasing nuclear size. As increased nuclear size within the same ploidy class is typical for most cancer cells, cancer specimens therefore contained relatively more "non-condensed" chromatin than normal urothelium. Analogously the relative values of "condensed" chromatin decreased in cancer specimens. Only in high-polyploid cancer cells, which occurred more frequently in undifferentiated tumours, a slight decrease of the relative area and content of "non-condensed" chromatin was observed as compared with well differentiated diploid tumour cells. It was in polyploid tumours that the absolute area and content of "condensed" chromatin was increased as compared with diploid normal urothelium. This means that the changes in "non-condensed" and "condensed" chromatin were primarily dependent on nuclear size and total chromatin content and were not found to be a characteristic of cancer nuclei as compared with control nuclei of the same size and ploidy. These findings differ from the results of biochemical analyses of heterochromatin both in cells during carcinogenesis and also in cancer cells, but are in agreement with qualitative and quantitative morphological studies of smeared cancer nuclei.

Carcinoma, Transitional Cell↗
PubMed1997

DNA content, ploidy level and number of nuclei in the human heart after myocardial infarction.

OBJECTIVE: Cardiac hypertrophy due to a prolonged functional activity is associated with an increase of cell size and polyploidization of the myocyte nuclei. Myocardial infarction is characterized by loss of myocytes. Increased load and as a consequence hypertrophic growth of the surviving myocardium has to be expected. The aim of this study was to investigate the response of cardiomyocytes after infarction. METHOD: Biochemical and cytophotometric analysis was performed on myocyte and connective tissue nuclei to determine whether the human heart after myocardial infarction is accompanied by an increase in the ploidy level, DNA content and in the number of nuclei. A total of 15 hearts obtained from autopsy material was studied, among them 8 after myocardial infarction. The number of nuclei was measured by indirect computation. RESULTS: We found a decrease of 4c and no significant difference of 2c nuclei in infarcted hearts. DNA ploidy level (> 8c) as well as the proportion of aneuploid myocyte nuclei were increased in infarcted hearts. DNA concentration and total DNA content were increased in the hearts after myocardial infarction. Numerical ratio of connective tissue nuclei/myocyte nuclei, total number of nuclei, number of myocyte nuclei and number of connective tissue nuclei were increased in infarcted hearts. CONCLUSION: Polyploidization and nuclear hyperplasia of myocytes may represent an adaptive response of the myocardium to an ischemic injury.

Adult↗
PubMed2003

Metal-catalyzed oxidation of extracellular matrix components perturbs hepatocyte survival with activation of intracellular signaling pathways.

To investigate whether oxidative manipulation of extracellular matrix components could affect cell survival, we studied primary rat hepatocytes cultured on dishes coated with collagen type 1, which was oxidized with a metal-based system. Culture of hepatocytes on oxidized collagen led to decreased cellular catalase activity along with impaired cell survival. The fraction of polyploid hepatocytes decreased early followed by greater reaccumulation of polyploid cells. Cells cultured on oxidized collagen showed greater susceptibility to additional oxidant stress induced by tert.-butyl-hydroperoxide. The capacity of hepatocytes for growth factor-induced DNA synthesis was unaffected by culture on oxidized collagen. In response to culture on oxidized matrix, AP-1, Egr-1, CREB, and NF-kappaB transcription factor activity was rapidly increased. This change in transcription factor activity was ameliorated by treatment of collagen with a free radical spin trap, N-tert.-butyl-alpha-phenylnitrone, prior to oxidation. Moreover, culture of hepatocytes with aminoguanidine, an antioxidant drug, decreased cell injury. These findings established that exposure of primary hepatocytes to oxidized extracellular matrix components rapidly activates cell signaling events with loss of hepatocyte subpopulations. Such cell-extracellular matrix interactions may play roles in organ homeostasis and oncogenetic progression.

Animals↗
PubMed2003

Chromosomal information derived from single blastomeres isolated from cleavage-stage embryos and cultured in vitro.

OBJECTIVE: To evaluate the potential of proliferation of single blastomeres isolated from human cleavage-stage embryos for use in preimplantation genetic diagnosis of chromosomal abnormalities. DESIGN: A laboratory study of chromosomal content of blastomeres isolated from embryos of patients from an in vitro fertilization program. SETTING: University hospital laboratory. PATIENT(S): Couples undergoing IVF or ICSI. INTERVENTION(S): Blastomeres were isolated from normally fertilized cleavage-stage human embryos, cultured in vitro or fixed immediately, and analyzed by fluorescence in situ hybridization (FISH) probes. MAIN OUTCOME MEASURES: Chromosomal information yielded by blastomeres cultured in vitro compared with those obtained from blastomeres that were processed for chromosomal analysis directly after isolation. RESULT(S): The percentage of cultured blastomeres that produced FISH results was significantly lower than the percentage of blastomeres processed for FISH directly after isolation (72% vs. 90%). Lack of FISH results from cultured cells, which in most cases was related to nuclear anomalies, was significantly more frequent among nondivided than divided blastomeres (39% vs. 21%). Both cultured and noncultured cells showed diploid, aneuploid and polyploid chromosome complements on FISH. Compared with directly processed cells, cultured cells yielded a higher proportion of polyploid patterns (22.9% vs. 6.1%). Of the cultured blastomeres that divided, 18% produced progeny with mosaicism. CONCLUSION(S): Although blastomere culture may increase the number of cells available for chromosomal analysis, the high frequency of nuclear defects and the occurrence of polyploidy and mosaicism among cultured cells discourage the use of blastomere isolation and proliferation strategy for use in preimplantation genetic diagnosis.

Adult↗
PubMed1996

Sex determination by simultaneous application of polymerase chain reaction and fluorescent in situ hybridization on the same blastomere of a pre-embryo.

OBJECTIVE: To describe an investigation of the feasibility of carrying out polymerase chain reaction (PCR) and fluorescent in situ hybridization on the same single human cell for sex determination. DESIGN: To develop protocol for a clinical diagnostic test in preclinical trials. SETTING: Infertile human volunteers in a clinical environment. PATIENTS: Polyploid embryos were obtained from patients treated by IVF at the Advanced Institute of Fertility. INTERVENTIONS: Seventeen blastomeres biopsied from human polyploid embryos were analyzed for sex determination by simultaneous application of PCR and fluorescent in situ hybridization. MAIN OUTCOME MEASURE: Presence of an X- or X and Y-chromosome band after agarose gel electrophoresis of PCR products and presence of an X- or X and Y-chromosome fluorescent probe signal after fluorescent in situ hybridization following PCR analysis. RESULTS: By PCR, all 17 blastomeres were amplified and, by fluorescent in situ hybridization, 12 (70.6%) blastomeres produced signals that were consistent with PCR results. Two blastomeres showed only X signals, although by PCR they had both X and Y-chromosome bands. CONCLUSIONS: The sequential use of PCR and fluorescent in situ hybridization on the same blastomere can be applied to improve the accuracy of sex determination before fresh ET.

Base Sequence↗
PubMed1985

Mitotic-cyclic and cycle-independent growth of cardiomyocytes.

The number of myocytes in mouse heart ventricles increased by 25% to 30%, on average, mainly for 3 days after birth. The mean myocyte number was 1.87 +/- 0.04 X 10(6) in 3-week-old and older mice, while the individual values varied up to 25% in any age group. In newborn mice, up to 90% of the myocytes were diploid cells, then polyploidization occurred. The stable ratio of ploidy classes was observed from 3 weeks to 1 year of age. The main class was always binucleate 2c X 2, comprising approximately 80% of the entire population. Nor were many mononucleate tetraploids (4c) and octaploids of different types (8c, 4c X 2, 2c X 4, 2c + 2c + 4c) observed. An insignificant number of hexadecaploids (16c and 8c X 2) could be found in some animals. The mean protein content in myocytes was not always directly proportional to the weight of the ventricles. These data and a certain discrepancy between calculated wet and measured dry weights allowed us to assume that the water content and the non-muscle component of myocardium varied from heart to heart. In growing myocytes of different ploidy, the ratio of the myocyte masses did not correspond to the genome ratio 2: 4: 8: 16 being equal to 2: 3.3: 5.0: 6.3. Thus the growth of the cells outside mitotic cycle differs from that during polyploidization.

Animals↗
PubMed1986

Flow cytometry of renal oncocytoma: common occurrence of deoxyribonucleic acid polyploidy and aneuploidy.

Flow cytometry was performed on 51 typical specimens of renal oncocytoma. Nuclei were extracted from paraffin-embedded archival material and isolated nuclei were stained with propidium iodide. Of the 51 available tissue blocks 86 per cent were evaluable and 50 per cent of these samples showed a deoxyribonucleic acid (DNA) histogram that was approximately the same as normal renal parenchyma. Of the oncocytoma samples 39 per cent showed a marked increase (more than 10 per cent of the nuclei) in the tetraploid DNA peak, while 11 per cent showed a distinct DNA aneuploid peak. Among 21 evaluable grade 2 oncocytic renal tumors 33 per cent showed a normal DNA histogram, 43 per cent showed a marked increase in the DNA tetraploid peak and 24 per cent showed a DNA aneuploid peak. The common presence of polyploid nuclei containing double quantities of chromosomal DNA may correlate with the long-standing pathological observation that oncocytic tumors often contain a distinct population of large nuclei. Indeed, 86 per cent concurrence was seen between the detection of an abnormal DNA content by flow cytometry and the histopathological presence of large abnormal nuclei in these specimens. Since renal oncocytomas (grade 1 oncocytic tumors) rarely, if ever, metastasize and are relatively noninvasive locally, their markedly abnormal flow cytometry patterns are of considerable interest. Moreover, DNA polyploidy has not been identified previously in renal tumors. The biological significance and mechanism of DNA polyploidy, and the relationship of DNA polyploidy and DNA aneuploidy to the pathogenesis of oncocytic renal tumors require further laboratory investigation. The clinical use of flow cytometry to classify and to predict the behavior of renal tumors will be complicated, since renal oncocytomas commonly have polyploid and aneuploid DNA histograms.

Adenoma↗
PubMed2002

Spontaneous and induced aneuploidy, considerations which may influence chromosome malsegregation.

Aneuploidy plays a major role in the production of human birth defects and is becoming increasingly recognised as a critical event in the etiology of a wide range of human cancers. Thus, the detection of aneuploidy and the characterisation of the mechanisms which lead to chromosome malsegregation is an important area of genotoxicological research. As an aid to aneuploidy research, methods have been developed to analyse the mechanisms of chromosome malsegregation and to investigate the role of aneuploidy in tumour progression. The presence of aneuploid cells is a common characteristic of many of tumour cell types as illustrated by the wide range of chromosome number changes detected in post-menopausal breast tumours. To investigate the time of occurrence of aneuploidy during tumour progression, we have studied the chromosome number status of Syrian hamster dermal (SHD) cells cultures progressing to morphological transformation. The production of both polyploid and aneuploid cells is a common feature of progressing cells in this model. The elevation of both progression to morphological transformation and aneuploid frequencies can be produced by exposure to a diverse range of carcinogens and tumour promoters. Analysis of the genotoxic activity of the hormone 17-beta oestradiol demonstrated its ability to induce both chromosome loss and non-disjunction in human lymphoblastoid cells implicating aneugenic activity in hormone related cancers. Mutations in the p53 tumour suppressor gene introduced into human fibroblasts produced modifications in chromosome separation at mitosis which may lead to the production of both aneuploidy and polyploid cells. Our studies indicate that the production of aneuploid cells can be influenced by both endogenous and exogenous factors and occur throughout the progression of normal cells to a malignant phenotype.

Alkylating Agents↗
PubMed2003

Effect of microcystin-LR and cyanobacterial extract from Polish reservoir of drinking water on cell cycle progression, mitotic spindle, and apoptosis in CHO-K1 cells.

Microcystin-LR is a cyanobacterial toxin possessing a potent tumor-promoting activity mediated through inhibition of protein phosphatases PP1 and PP2A. Because these enzymes are involved in fundamental cell processes, we decided to examine the influence of microcystin-LR on cell cycle progression, onset of anaphase, segregation of chromosomes by the mitotic spindle, and apoptosis in Chinese hamster ovary (CHO-K1) cells. Cells were incubated with 25, 50, and 100 microM of pure microcystin-LR and a cyanobacterial extract for 14, 18, and 22 h. Giemsa staining of cells treated with these toxins revealed a dose- and time-dependent increase of mitotic indices, accumulation of abnormal G(2)/M figures with hypercondensed chromosomes, abnormal anaphases with defective chromosome separation, and polyploid cells. Because spindle checkpoint is a fundamental regulatory mechanism that assures the onset of anaphase and subsequent exit from mitosis, we examined the spindle organization in microcystin-treated cells. The majority of the mitotic cells showed monopolar and multipolar mitotic spindles (multiple asters). Microtubule bundles were present in interphase cells. Our results indicate that microcystin-LR induces apoptosis and necrosis in a dose- and time-dependent manner and that the frequency of dead cells cells is positively correlated with the frequency of polyploid cells.

Animals↗
PubMed1998

Age-associated mosaicism and polyploidy in Down's syndrome.

Age-related increases in the frequencies of cells with chromosome 21 loss and of polyploid cells were documented in short-term peripheral blood lymphocyte cultures from 54 patients with Down's syndrome (DS), ages 0 to 48 years. The polyploid data, together with previous work from this laboratory with non-DS subjects, suggest that this may be a useful indicator of aging in lymphocytes.

Adolescent↗
PubMed2001

Chromosome analysis and comparison of the benign cystic and malignant squamous component of an ovarian teratoma.

Teratoma, the most common ovarian germ-cell tumor, presumably arises from a single germ cell and is composed of tissues representing all germ layers (ectoderm, mesoderm, and endoderm). Benign cystic teratomas (dermoid cyst) represent over 95% of ovarian teratomas and are comprised of entirely mature adult tissues. When malignant, almost all mature teratomas contain squamous carcinoma. We report for the first time the karyotypic comparison of an ovarian teratoma in a 36-year-old female with tissue separately taken from the benign cystic and malignant squamous components. The malignant squamous component revealed two distinct karyotypic populations: one diploid and the other polyploid. Both, however, demonstrated two common markers. The polyploid population also demonstrated numerous additional abnormalities with multiple copies of chromosome 20. Though many of the chromosomal aberrations were unique to the benign component, several karyotypes showed the same markers noted in the malignant squamous component. The significance of this finding is that it may serve to identify those histologically benign teratomas destined to undergo malignant transformation.

Adult↗
PubMed1999

Near-haploidy in a malignant sacrococcygeal teratoma.

Cytogenetic analysis of a malignant sacrococcygeal teratoma in an adult patient revealed near-haploid (77%), near-diploid (19%), and polyploid (4%) cells. The near-haploid cells had a karyotype of 25,XX,der(5)t(5;7)(p15;p13),+7,der(9)t(6;9)(p21;q34),r(17)(p13q25) . In the near-diploid and polyploid cells identical copies of the structural chromosomal changes were found. Although some of the anomalies observed appear unique to this case, a common breakpoint in chromosome 6 was previously reported as specific in a subgroup of extragonadal germ cell tumors of adults.

Aged↗
PubMed1997

Heterogeneity of DNA content and expression of cell cycle genes in axenically growing Entamoeba histolytica HM1:IMSS clone A.

The cell division cycle of Entamoeba histolytica was studied using multi-parametric flow cytometry in asynchronous and partially synchronised cells. Dynamic changes in the DNA synthesis and DNA content of axenically growing trophozoites were observed by using 5-bromo-2'-deoxyuridine (BrdU) uptake and DNA specific fluorochromes. It was observed that DNA synthesis in these cells continues beyond the typical S-phase stop point when DNA duplication is complete. Asynchronously growing E. histolytica cells could be synchronised by serum starvation followed by serum re-addition. BrdU incorporation in synchronised cells showed that cell synchrony is maintained for at least one generation time, in which the G1 phase lasts for 2-3 h and the S-phase lasts for 5-6 h. Analysis of our results revealed that E. histolytica trophozoites, growing in axenic medium, are made up of a heterogenous population of euploid and polyploid cells. The number of polyploid cells increases with age of the cells in culture. Expression of putative cell cycle and signal transduction markers was studied using specific antibodies and changes in their expression levels have been correlated with changes in the DNA content. Based upon our results we could identify G1, S and G2 phases of the cell cycle of E. histolytica and also predict the mechanism underlying the generation of polyploidy in these cells, which may have significant effects on its biology and pathogenesis.

Animals↗
PubMed1988

Comparison of computerized analysis of nuclear DNA changes in uterine cervix dysplasia and in urothelial non-invasive papillary carcinoma.

The nuclear DNA content was measured in preneoplastic lesions of the uterine cervix and in papillary carcinomas of the bladder. Three groups of features were calculated from the raw data: basic DNA, DNA deviation and DNA distribution. The basic DNA features, concerning both the cervix and the bladder, showed a progressive increase in the mean DNA content, a decrease in the percentage of diploid nuclei and steadily increasing values of polyploid and aneuploid nuclei. Among the DNA deviation features, the malignancy grade value was zero in the normal cervical epithelium and in the normal urothelium. An increase in this value was evident in moderate dysplasia and in urothelial papillary carcinoma of grade 2, the highest value being in CIS and in grade 3. Concerning the DNA distribution features, the values of the 15th and 95th percentiles and their difference were progressively higher both in the cervix and in the bladder, expressing a continuous shift and spread of the DNA content measurements in the different diagnostic categories, with respect to normal epithelium and urothelium. The statistical analysis showed that the strongest correlation is between 2c D.I. and % of polyploid nuclei in the cervix and between M.I. and % of aneuploid nuclei greater than 4c in the bladder. In the cervix the most discriminating feature is the Malignancy Grade, whereas in the bladder it is the percentage of diploid nuclei. The comparison between the results of the three groups of features showed that: 1) Mild dysplasia of the cervix and urothelial papillary carcinoma of grade 1 showed similar changes in DNA features. Both were basically characterized by increased proliferative activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinoma, Papillary↗
PubMed2003

Molecular evolution of rDNA external transcribed spacer and phylogeny of sect. Petota (genus Solanum).

The 5(') external transcribed spacer (ETS) region of ribosomal DNA of 30 species of Solanum sect. Petota and the European Solanum dulcamara were compared. Two structural elements can be distinguished in the ETS: (i). a variable region (VR), demonstrating significant structural rearrangements and (ii). a conservative region (CR), evolving mainly by base substitutions. In VR, a conservative element (CE) with similarity to the ETS of distantly related Nicotiana is present. The ancestral organization of ETS (variant A) was found for non-tuber-bearing species of ser. Etuberosa, tuber-bearing wild potatoes of Central American ser. Bulbocastana, Pinnatisecta, and Polyadenia and S. dulcamara. Duplication of CE took place in the ETS of species from ser. Commersoniana and Circaeifolia (variant B). South American diploids and Mexican polyploids from superser. Rotata also possess two CE, and additionally two duplications around CE1 are present in VR (variant C). Three major lineages could be distinguished: non-tuber-bearing species of ser. Etuberosa, tuber-bearing Central American diploids and all South American species radiated from a common ancestor at early stages of evolution, indicating a South American origin of the tuber-bearing species. Later, Central and South American diploids evolved further as independent lineages. South American species form a monophyletic group composed of series with both stellata and rotata flower morphology. Solanum commersonii represents a sister taxon for all rotata species, whereas ser. Circaeifolia diverged earlier. Two main groups, C1 and C2, may be distinguished for species possessing ETS variant C. C1 contains ser. Megistacroloba, Conicibaccata, Maglia, and Acaulia, whereas all diploids of ser. Tuberosa are combined into C2. A closer relationship of Solanum chacoense (ser. Yungasensa) to the C2 group was found. The origin of polyploid species Solanum maglia, Solanum acaule, Solanum tuberosum, Solanum iopetalum, and Solanum demissum is discussed.

Base Sequence↗
PubMed2002

Epialleles - a source of random variation in times of stress.

With the advent of biotechnology, epigenetics has gained in respectability. Recently, focus has moved away from the problems caused by the epigenetic silencing of transgenes to the adaptive advantages offered by stochastic epigenetic variation. Epialleles can form in response to environmental and genomic stresses, including polyploidization. They may be important in acclimation to a range of environmental conditions and in stabilizing polyploid genomes.

Acclimatization↗
PubMed2003

Dual roles of human BubR1, a mitotic checkpoint kinase, in the monitoring of chromosomal instability.

In this study, we show that the formation of polyploidy following sustained mitotic checkpoint activation appears to be preceded by the ubiquitin-dependent proteolysis of hBubR1. In addition, the level of hBubR1 is significantly reduced not only in polyploid cells created by sustained mitotic spindle damage, but also in 21 (31.3%) of 67 human colon adenocarcinomas tested. Importantly, the introduction of hBubR1 triggers the apoptosis of polyploid cells formed by aberrant exit from mitosis and inhibits the growth of tumors established with these cells in athymic nude mice. These results suggest that hBubR1-mediated apoptosis prevents the propagation of cells that breach the mitotic checkpoint and that the control of hBubR1 protein level is an important factor in the acquisition of preneoplastic polyploidy.

Adenocarcinoma↗
PubMed2002

Sonohysterographic appearances of endometrial carcinoma: an in vitro study of uterine specimens.

OBJECTIVE: To determine the sonohysterographic appearances of endometrial carcinoma by sonohysterographic examination of uterine specimens. METHODS: A prospective study of sonohysterographic examination on 30 uteri obtained immediately after hysterectomy from women 30 to 86 years of age, diagnosed preoperatively with endometrial carcinoma. The transducer was applied directly on the serosal surface of the anterior uterine wall for sonographic visualization. Sonographic examination was performed initially to assess the endometrial thickness, followed by infusion of normal saline into the endometrial cavity through a Foley catheter inserted into the cervix and repeat sonographic evaluation to characterize endometrial carcinoma. RESULTS: The mean (+/- SD) endometrial thickness on initial sonographic examination was 11.4 (+/- 6.6) mm. Sonohysterographic examination demonstrated 15 uteri to have large, irregular polyploid masses arising from the endometrium, 6 uteri to have focal endometrial thickening, 4 uteri to contain benign-appearing polyp(s), 2 uteri to contain benign-appearing polyp(s) with focal endometrial thickening, and 3 uteri to have normal endometria. CONCLUSION: The sonohysterographic appearance of endometrial carcinoma is variable. Although the majority of endometrial carcinomas appeared as large, irregular polyploid masses, a completely normal sonohysterographic appearance may occur.

Adult↗