Search results for "Metaphase"
showing 10 items of 35 documents
Identification of novel drug resistance mechanisms by genomic and transcriptomic profiling of glioblastoma cells with mutation-activated EGFR.
2021
Abstract Aims Epidermal growth factor receptor (EGFR) is not only involved in carcinogenesis, but also in chemoresistance. We characterized U87.MGΔEGFR glioblastoma cells with constitutively active EGFR due to deletion at the ligand binding domain in terms of gene expression profiling and chromosomal aberrations. Wild-type U87.MG cells served as control. Materials and methods RNA sequencing and network analyses (Ingenuity Pathway Analysis) were performed to identify novel drug resistance mechanisms related to expression of mutation activated EGFR. Chromosomal aberrations were characterized by multicolor fluorescence in situ hybridization (mFISH) and array comparative genomic hybridization (…
An overview on anti-tubulin agents for the treatment of lymphoma patients
2020
Anti-tubulin agents constitute a large class of compounds with broad activity both in solid tumors and hematologic malignancies, due to the interference with microtubule dynamics. Since microtubules play crucial roles in the regulation of the mitotic spindles, the interference with their function usually leads to a block in cell division with arrest at the metaphase/anaphase junction of mitosis, followed to apoptosis. This explains the reason why tubulin-binding agents (TBAs) proved to be extremely active in patients with cancer. Several anti-tubulin agents are indicated in the treatment of patients with lymphomas both alone and in combination chemotherapy regimens. The article reviews the …
Differential long non-coding RNA expression profiles in human oocytes and cumulus cells
2018
AbstractProgress in assisted reproductive technologies strongly relies on understanding the regulation of the dialogue between oocyte and cumulus cells (CCs). Little is known about the role of long non-coding RNAs (lncRNAs) in the human cumulus-oocyte complex (COC). To this aim, publicly available RNA-sequencing data were analyzed to identify lncRNAs that were abundant in metaphase II (MII) oocytes (BCAR4, C3orf56, TUNAR, OOEP-AS1, CASC18, and LINC01118) and CCs (NEAT1, MALAT1, ANXA2P2, MEG3, IL6STP1, and VIM-AS1). These data were validated by RT-qPCR analysis using independent oocytes and CC samples. The functions of the identified lncRNAs were then predicted by constructing lncRNA-mRNA co…
Genotoxicity of selected pesticides in the mouse bone-marrow micronucleus test and in the sister-chromatid exchange test with human lymphocytes in vi…
1996
Selected pesticides (aldicarb, 1,3-dichloropropene, methidathion, parathion, triadimefon, vinclozolin) were tested for their clastogenic and aneugenic activities in the mouse bone-marrow micronucleus (MN) test in vivo and for their sister-chromatid exchange-inducing activities in human lymphocytes in vitro in the presence and absence of an exogenous metabolizing system from rat-liver S9. 1,3-Dichloropropene significantly increased the frequencies of micronucleated polychromatic erythrocytes (PCE) in bone-marrow cells of female mice from 3.3 MN/1000 PCE to 15.3 MN/1000 PCE (187 mg per kg body weight). 1,3-Dichloropropene (100 microM) induced 16.0 SCE/metaphase after 24 h of incubation as com…
Female obesity impairs in vitro fertilization outcome without affecting embryo quality.
2008
Objective To compare embryo quality and reproductive outcome in our IVF program according to the women's body mass index (BMI). Design Retrospective study. Setting University-affiliated infertility clinic, between January 2001 and April 2007. Patient(s) Women undergoing a total of 6,500 IVF–intracytoplasmic sperm injection (ICSI) cycles. Intervention(s) Six thousand five hundred IVF-ICSI cycles were included and divided into four groups: lean ( 2 ; n=1,070; 16.5%); normal (20–24.9 kg/m 2 ; n=3,930; 60.5%); overweight (25–29.9 kg/m 2 ; n=1,081; 16.6%); and obese (≥30 kg/m 2 ; n=419; 6.4%). Main Outcome Measure(s) Comparison of embryo quality and reproductive outcome (implantation, pregnancy,…
The follicular hormonal profile in low-responder patients undergoing unstimulated cycles: is it hypoandrogenic?
2012
STUDY QUESTION What is the final hormonal milieu of pre-ovulatory follicles of low-responder (LR) patients undergoing unstimulated cycles? SUMMARY ANSWER Neither androgen secretion nor LH was impaired in pre-ovulatory follicles of LR women. WHAT IS KNOWN ALREADY Therapies currently used to improve ovarian response in LR women have an impact on the final hormonal follicular milieu, and these changes are believed to be partially responsible for determining the success rate in these women. Surprisingly, as far as we know, there is no report of the final hormonal profile of LR women undergoing unstimulated cycles or evidence that follicular androgen secretion in LR women is impaired. STUDY DESI…
Direct detection of repetitive, whole chromosome paint and telomere DNA probes by immunogold electron microscopy
1993
Biotinylated repetitive, whole chromosome paint and telomere DNA probes were investigated at the electron microscope level after non-isotopic in situ hybridization and direct immunogold detection. The protocol described allowed the visualization of a biotinylated chromosome 1 specific satellite DNA probe in the light microscope without silver intensification. This sensitive method was exploited to analyse factors contributing to signal strength in immunogold chromosome painting. Furthermore, it allowed us to investigate the distribution of (TTAGGG)n telomere repeats in human metaphase chromosomes and interphase nuclei. Telomeric and internal (TTAGGG)n repeats were detected at high spatial r…
Mid-region parathyroid hormone-related protein (PTHrP) binds chromatin of MDA-MB231 breast cancer cells and isolated oligonucleotides “in vitro”
2006
We have previously shown that PTHrP(38-94)-amide restrains growth and invasion "in vitro", causes striking toxicity and accelerates death of some breast cancer cell lines, the most responsive being MDA-MB231 whose tumorigenesis was also attenuated "in vivo". PTHrP(38-94)-amide contains the domain implicated in the nuclear import of PTHrP. Although the nucleus was identified as a destination for mid-region PTHrP, evidence for direct DNA-binding capability is lacking to date. Here, we examined the localization of PTHrP(38-94)-amide within MDA-MB231 cells and within metaphase spread preparations and characterized its DNA-binding properties, employing a combination of immunocytochemical, cytoge…
Maternal Oct-4 is a potential key regulator of the developmental competence of mouse oocytes
2008
Abstract Background The maternal contribution of transcripts and proteins supplied to the zygote is crucial for the progression from a gametic to an embryonic control of preimplantation development. Here we compared the transcriptional profiles of two types of mouse MII oocytes, one which is developmentally competent (MIISN oocyte), the other that ceases development at the 2-cell stage (MIINSN oocyte), with the aim of identifying genes and gene expression networks whose misregulated expression would contribute to a reduced developmental competence. Results We report that: 1) the transcription factor Oct-4 is absent in MIINSN oocytes, accounting for 2) the down-regulation of Stella, a matern…
Centromere-Like Elements in Megaselia Spiracularis (Diptera: Phoridae): A Fine-Structure and Cytogenetic Study
2004
The present study was concerned with the karyotype of a humpbacked fly, Megaselia spiracularis (Diptera: Phoridae). Chromosome preparations of neuroblasts isolated from male and female pupae uniformly showed two pairs of metacentric chromosomes and a telocentric chromosome pair. All chromosomes were homomorphic. The analysis of ultrathin serial sections through spermatogonia in metaphase using transmission electron microscopy, confirmed the presence of 3 regular chromosome pairs. In ultrathin sections, the centromeres could be detected as individual elements owing to their lesser electron density in comparison with the chromosome arms. In addition, the spindles contained two tiny elements s…