Search results for "Ploidy"

DNMT1 SILENCING ELICITS DIFFERENT CELL CYCLE RESPONSES IN PRIMARY VERSUS TUMOR CELLS AND IS ASSOCIATED WITH ANEUPLOIDY GENERATION

2011

DNMT1 depletion activates a pathway p14ARF/TP53 controlled that induces G1 arrest preventing DNA demethylation and aneuploidy

2011

Background: Aneuploidy is considered the result of chromosome segregation errors caused by defects in the mitotic spindle assembly, centrosome duplication, cell-cycle checkpoints and epigenetic changes. Usually, aneuploidy affects negatively proliferation of normal cells. However, it is frequently associated with cancer that is characterized by a uncontrolled proliferation. Thus, understanding the pathway(s) that block proliferation of aneuploid cells might open new avenue to exploit new cancer therapies. O bservations: We found that in primary human fi broblasts (IMR90) knocking down of DNMT1, a member of epigenetic machinery is perceived by the cell as a stress signal that induces p14ARF …

p14ARF re-expression induces apoptosis in aneuploid HCT116 cells

2012

Weakening the Spindle Assembly Checkpoint by reduced expression of its components such as MAD2, BubR1 and MPS1 induces chromosome instability and aneuploidy both hallmarks of cancer cells. p14ARF that is found frequently altered in human cancers, is overexpressed in response to oncogenic stimuli to stabilize p53 halting cell progression. Previously, we determined that lack or reduced expression of p14ARF is involved in the maintenance of aneuploid cells suggesting that it could be part of a pathway controlling proliferation of aneuploidy cells. To investigate further this aspect of p14ARF function it was ectopically expressed in HCT116 cells, a stable near diploid cell line, after MAD2 depl…

Simultaneous reduction of MAD2 and BUBR1 expression induces mitotic spindle alterations associated with p53 dependent cell cycle arrest and death

2014

pRb loss and chromosomal instability in human cells.

2009

pRb loss and chromosomal instability in human cells. Recent studies suggest that Retinoblastoma tumor suppressor (RB) plays important roles in the prevention of chromosomal instability by regulating genes that control cell cycle progression and mitotic events. We investigated the effects of stable post-transcriptional silencing of RB in primary human fibroblasts (IMR90) and in near-diploid colon cancer cells (HCT116) focusing on chromosome missegregation mechanisms. Stable depletion of pRb was achieved by infection with the retroviral vector MSCV-LMP670 encoding a microRNA (miR670) targeting RB transcript. Cytogenetic, immunofluorescence microscopy and time-lapse video-microscopy analyses s…

Identification of molecular markers involved in cellular response to aneuploidy in normal and tumor cells

2020

The retinoblastoma paradigm revisited

2008

Background: Retinoblastoma (Rb) is the most common primary malignant intraocular tumour in childhood. The "two hit" theory, formulated by Knudson in 1971 to explain the variegated clinical expression of the disease, led to the discovery of the so called tumour suppressor genes and the identification of the Rb1 as the prototype of such genes. Mutations of the Rb1 gene are now commonly believed to be the "cause" retinoblastoma, although epidemiological, clinical, and biological evidences argue against it. Material/Methods: The Authors have performed a systematic review of available data concerning clinical and diagnostic aspects of retinoblastoma, including molecular genetics. Meta analysis o…

DNA DEMETHYLATION CAUSED BY 5-AZA-2’-DEOXYCYTIDINE TREATMENT AFFECTS GENOME STABILITY BY INDUCING MITOTIC ALTERATIONS AND ANEUPLOIDY IN HCT-116 TUMOR…

2014

Identification of mechanism(s) leading to hyperdiploidy in progenitor tumor cells derived from MCF7 breast cancer cells

2010

Stem cells are a minor population of mostly resting cells defined by their long life, high clonogenicity, self-replicating potential, plasticity, and drug resistance (Finn, 2008). Cells with these properties have been identified in various normal and cancerous human tissues (Wicha, 2006), as well as in several long-term tumor cell lines (Setoguchi, 2004). We have some preliminary data indicating that cells isolated from MCF7 line divide slowly and form spheres, both features of progenitors tumor cells, when grown in ultralow adherent plates and in absence of serum. Furthermore, these features were associated to two distinct populations characterized by different content in terms of number o…

Hybridization studies inSilene subgen.Petrocoptis (Caryophyllaceae)

2006

Silene subgenusPetrocoptis comprises sexual diploid taxa and it is restricted to calcareous cliffs in the Iberian peninsula. Artificial crosses involvingSilene pyrenaica (Bergeret)Mayol etRossello (≡Petrocoptis pyrenaica (Bergeret)Walp.),Silene laxipruinosa Mayol etRossello andS. montserratii subsp.crassifolia (Rouy)Mayol etRossello (≡P. crassifolia Rouy) were attempted to assess the extent of barriers developed within the subgenusPetrocoptis. Usually, intraspecific crosses involving allopatric populations were successful, suggesting that geographically isolated populations are not genetically isolated. Cross-compatibility was noted among the polymorphicS. pyrenaica, which developed fertile…