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Metaphase Cells (metaphase + cell)
Selected AbstractsChromosome aberrations in peripheral blood lymphocytes of high-risk HPV-infected women with HGSILENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 9 2008Rosa E. Álvarez-Rosero Abstract Genomic instability is one of the main characteristics of malignant tumors, including HPV-induced cervical cancer. The aim of this study was to explore the use of assessing chromosome aberrations (CA) in peripheral blood lymphocytes as a biomarker for genomic instability in high-risk HPV-infected women with high-grade squamous intraepithelial lesions (HGSIL). A total of 120 women were recruited for this study, following cytology/colposcopy evaluation and HPV DNA detection. The study groups consisted of 30 HPV(+) women with histologically confirmed cervical intraepithelial neoplasia grade 2/3 and 30 HPV(+) women with carcinoma in situ (CIS). Two control groups, including 30 women HPV(,) and 30 women HPV(+), were recruited among women who were reported as cytology negative. Lymphocyte cell cultures were established for 52 hr, and 100 complete metaphase cells were evaluated per subject for CA analysis. The results show that women with CIS had significantly higher frequencies of both aneuploidy (0.67 ± 0.20 vs. 0.14 ± 0.08, P = 0.020) and tetraploidy (0.88 ± 0.23 vs. 0.17 ± 0.08, P = 0.013) in comparison with HPV(,) controls. These findings suggest the usefulness of peripheral blood lymphocytes to detect genomic instability associated with HPV-induced HGSIL. Environ. Mol. Mutagen., 2008. © 2008 Wiley-Liss, Inc. [source] Comprehensive analysis of the ICEN (Interphase Centromere Complex) components enriched in the CENP-A chromatin of human cellsGENES TO CELLS, Issue 6 2006Hiroshi Izuta The centromere is a chromatin structure essential for correct segregation of sister chromatids, and defects in this region often lead to aneuploidy and cancer. We have previously reported purification of the interphase centromere complex (ICEN) from HeLa cells, and have demonstrated the presence of 40 proteins (ICEN1,40), along with CENP-A, -B, -C, -H and hMis6, by proteomic analysis. Here we report analysis of seven ICEN components with unknown function. Centromere localization of EGFP-tagged ICEN22, 24, 32, 33, 36, 37 and 39 was observed in transformant cells. Depletion of each of these proteins by short RNA interference produced abnormal metaphase cells carrying misaligned chromosomes and also produced cells containing aneuploid chromosomes, implying that these ICEN proteins take part in kinetochore functions. Interestingly, in the ICEN22, 32, 33, 37 or 39 siRNA-transfected cells, CENP-H and hMis6 signals disappeared from all the centromeres in abnormal mitotic cells containing misaligned chromosomes. These results suggest that the seven components of the ICEN complex are predominantly localized at the centromeres and are required for kinetochore function perhaps through or not through loading of CENP-H and hMis6 onto the centromere. [source] Order of genetic events is critical determinant of aberrations in chromosome count and structureGENES, CHROMOSOMES AND CANCER, Issue 4 2004Christine Fauth A sequential acquisition of genetic events is critical in tumorigenesis. A key step is the attainment of infinite proliferative potential. Acquisition of this immortalization requires the activation of telomerase in addition to other activities, including inactivation of TP53 and the retinoblastoma family of tumor-suppressor proteins. However, the importance of the order in which these genetic events occur has not been established. To address this question, we used a panel of normal mammary fibroblasts and endothelial cultures that were immortalized after transduction with the catalytic subunit of telomerase (hTERT) and a temperature-sensitive mutant of the SV40 large-tumor (tsLT) oncoprotein in different orders in early- and late-passage stocks. These lines were maintained in continuous culture for up to 90 passages, equivalent to >300 population doublings (PDs) post-explantation during 3 years of continuous propagation. We karyotyped the cultures at different passages. Cultures that received hTERT first followed by tsLT maintained a near-diploid karyotype for more than 150 PDs. However, in late-passage stocks (>200 PDs), metaphase cells were mostly aneuploid. In contrast, the reverse order of gene transduction resulted in a marked early aneuploidy and chromosomal instability, already visible after 50 PDs. These results suggest that the order of genetic mutations is a critical determinant of chromosome count and structural aberration events. © 2004 Wiley-Liss, Inc. [source] Comprehensive karyotyping of the HT-29 colon adenocarcinoma cell lineGENES, CHROMOSOMES AND CANCER, Issue 1 2002Kanji Kawai The tumor cell line HT-29 was derived from a primary adenocarcinoma of the rectosigmoid colon. HT-29 is hypertriploid (3n+) and has accumulated numerous chromosomal structural aberrations. To identify material involved in chromosome rearrangements, we performed a comprehensive cytogenetic analysis using G-banding, spectral karyotyping (SKY), and fluorescence in situ hybridization (FISH). The combination of molecular cytogenetic techniques enabled us to define the first comprehensive karyotype for HT-29. Seventeen marker chromosomes were found in 75,100% of metaphase cells, generally in a single copy per cell. We confirmed the composition of eight previously described markers, refined the classification of seven others, and identified two novel marker chromosomes. Notable aberrations included a reciprocal translocation between chromosomes 6 and 14 and an unusual, large derivative chromosome 8 composed entirely of 8q material. The telomere status, evaluated by FISH, revealed telomeric signals at the termini of all chromosomes. No interstitial telomeric sequences were observed in any cell. Although numerous chromosomal aberrations are present in HT-29, the cell line appears to have retained a high level of genomic stability during passage in culture since undergoing transformation. The excellent resolving power of SKY, coupled with additional information obtained from molecular cytogenetic analyses, will improve our ability to identify genetic lesions characteristic of cancer. © 2002 Wiley-Liss, Inc. [source] Karyotypic similarity identified by multiplex-FISH relates four prostate adenocarcinoma cell lines: PC-3, PPC-1, ALVA-31, and ALVA-41GENES, CHROMOSOMES AND CANCER, Issue 4 2001Marileila Varella-Garcia Recently developed molecular cytogenetic techniques for karyotyping are providing new and important insights regarding the chromosomal changes that occur in solid tumors. We used multiplex-FISH to analyze four adenocarcinoma cell lines, PC-3, PPC-1, ALVA-31, and ALVA-41, in which the characterization of a large number of rearranged chromosomes was partially or substantially inconclusive by G-banding. Although the original descriptions of these lines depict them as distinct entities established from different patients, this study demonstrates that these four lines share numerous, highly rearranged chromosomes, strongly supporting the conclusion that they are derived from the same patient material. Our analysis indicates that PPC-1, ALVA-31, and ALVA-41 were derived from PC-3 through mechanisms involving clonal progression represented by sequential changes and clonal diversion represented by differing patterns of changes. Extensive cellular heterogeneity was detected in all four lines, and most rearrangements included segments derived from multiple chromosomes. Each line also showed a set of unique derivative chromosomes. However, a limited number of metaphase cells (approximately 10) was analyzed for each line, and numerous single-cell abnormalities were detected in all of them. Therefore, it is plausible that the number of clonal, shared, and/or unique rearrangements has been underestimated. These cell lines have been utilized as models for understanding the biology of prostate cancer and reportedly differ in their cell physiology. Rather than detracting from their value, a complete understanding of the interrelationships of these lines to one another may provide the opportunity to define the molecular changes that have led to their individual malignant phenotypes. © 2001 Wiley-Liss, Inc. [source] Prenatal diagnosis of occipital encephalocele, mega-cisterna magna, mesomelic shortening, and clubfeet associated with pure tetrasomy 20pPRENATAL DIAGNOSIS, Issue 2 2003Yi-Cheng Wu Abstract We present the first case of a fetus with pure tetrasomy 20p proven by cord-blood sampling at 24 weeks of gestation. This case was diagnosed in utero with multiple congenital anomalies including occipital encephalocele, mega-cisterna magna, mesomelic shortening, and clubfeet. An analysis of GTG-banded chromosomes of 20 metaphase cells was performed. Female karyotype [47,XX, +i(20)(p10)] was revealed in all cells. Pure tetrasomy 20p was confirmed using fluorescent in situ hybridization (FISH) with a telomere probe for chromosome 20p in all seven metaphase cells. The pregnancy was terminated because of associated multiple anomalies and severe oligohydramnios. The postmortem examination confirmed the prenatal diagnosis. Copyright © 2003 John Wiley & Sons, Ltd. [source] | ||||||||||