Search results for "pRb"

Centrosome amplification induced by hydroxyurea leads to aneuploidy in pRB deficient human and mouse fibroblasts.

2006

Alterations in the number and/or morphology of centrosomes are frequently observed in human tumours. However, it is still debated if a direct link between supernumerary centrosomes and tumorigenesis exists and if centrosome amplification could directly cause aneuploidy. Here, we report that hydroxyurea treatment induced centrosome amplification in both human fibroblasts expressing the HPV16 -E6-E7 oncoproteins, which act principally by targeting p53 and pRB, respectively, and in conditional pRB deficient mouse fibroblasts. Following hydroxyurea removal both normal and p53 deficient human fibroblasts arrested. On the contrary pRB deficient fibroblasts entered the cell cycle generating aneupl…

pRb suppresses camptothecin-induced apoptosis in human osteosarcoma Saos-2 cells by inhibiting c-Jun N-terminal kinase

2001

AbstractThis paper studies the cytotoxic effect induced by the topoisomerase I inhibitor camptothecin in human osteosarcoma Saos-2 cells, which lack p53 and contain a non-functional form of the product of the retinoblastoma gene, pRb. Cytotoxicity induced by camptothecin was dose- and time-dependent; the treatment with 100 nM camptothecin reduced cell viability by 50% at 32 h and by 75% at 72 h of exposure. The cytotoxic effect was caused by apoptosis, as ascertained by morphological evidence, acridine orange-ethidium bromide staining and flow cytometric analysis. Apoptosis was accompanied by both the activation of caspase-3 and the fragmentation of poly(ADP-ribose) polymerase. Treatment wi…

BIOLOGICAL DENITRIFICATION OF GROUNDWATER: BIO-PRB COLUMN TEST PERFORMANCES EVALUATION

2012

The occurrence of nitrates in groundwater is steadily raising concern due to possible health consequences of nitrate ingestion. Biological denitrification in BIO-PRB is the enhancement of a natural process that occurs naturally when bacteria live in an environment void of oxygen with carbon availability. Bio-PRB represent a perspective of development for PRB technique but, despite the fact that this technology has already been widely used for chlorinated solvents, data on denitrification PRBs are still scarce. This paper reports on the results of an experimental study carried out for 214 days on a bench-scale pilot column (10 cm in internal diameter and 100 cm in length with sampling ports …

RNAi mediated acute depletion of Retinoblastoma protein (pRb) promotes aneuploidy in human primary cells via micronuclei formation

2009

BACKGROUND: Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB) participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA) specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. RESULTS: Acutely pRb-depleted fibr…

Adenoviral RB2/p130 gene transfer inhibits smooth muscle cell proliferation and prevents restenosis after angioplasty.

1999

Abstract —Smooth muscle cell (SMC) proliferation that results in neointima formation is implicated in the pathogenesis of atherosclerotic plaques and accounts for the high rates of restenosis that occur after percutaneous transluminal coronary angioplasty, a widespread treatment for coronary artery disease. Endothelial lesions trigger intense proliferative signals to the SMCs of the subintima, stimulating their reentry into the cell cycle from a resting G 0 state, resulting in neointima formation and vascular occlusion. Cellular proliferation is negatively controlled by growth-regulatory or tumor-suppressor genes, or both, such as the retinoblastoma gene family members ( RB/p105, p107, RB2…

Transient and stable depletion of RB induce different expression of genes involved in epigenetic modifications.

2008

Uso del nocciolino di oliva come materiale di riempimento di biotrincee per la denitrificazione biologica in situ di acque di falda

2016

Tra le varie possibilità di intervento per la rimozione dei nitrati dalle acque di falda, notevole interesse suscita il trattamento in situ dei plume contaminati mediante la realizzazione di biotrincee denitrificanti scavate in situ e naturalmente attraversate dalle acque di falda. Tra i materiali di origine organica che sono stati testati per tali applicazioni, il nocciolino di olive è risultato uno dei più idonei alle potenziali applicazioni di pieno campo. Tale tipo di materiale possiede un elevato contenuto di carbonio organico totale, prossimo al 50%, e una percentuale di lignina prossima al 45% in peso. Il lavoro proposto riporta i risultati di una campagna sperimentale eseguita media…

Synthesis and antiproliferative activity of 3-amino-N-phenyl-1H-indazole-1-carboxamides

2007

Abstract A series of new 3-amino-N-phenyl-1H-indazole-1-carboxamides 10 have been prepared from commercially available phenyl isocyanate precursors 8 and 3-aminoindazole 9. Some of the synthesized compounds were evaluated for their in vitro antineoplastic activity against 60 human cell lines derived from seven clinically isolated cancer types (lung, colon, melanoma, renal, ovarian, brain, and leukemia) according to the NCI standard protocol. The test results indicated that 3-amino-1H-indazole-1-carboxamides 10 were endowed with an interesting antiproliferative activity. The most active compounds of this series, 10d,e, were able to inhibit cell growth of many neoplastic cell lines at concent…

Synthesis and antiproliferative activity of new derivatives containing the polycyclic system 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3’,4’:2,3]azep…

2013

The reaction under reflux between 1-phenyl-3-R-5-methylaminopyrazoles and 2,5-hexanedione lead to 5,7:7,13-dimethanopyrazolo[3,4-b]pyrazolo[3′,4′:2,3]azepino[4,5-f]azocine derivatives 3b–g. These unusual molecules show the structural complexity of many biologically active natural products and are endowed with the chemical diversity that is required in drug discovery. The compounds 3b,e were reduced by hydrogen in the presence of Palladium on activated charcoal to give the dihydro derivatives 5b,e. Compounds 3b–f and 5b,e were selected by the NCI to evaluate their in vitro antiproliferative activity against 60 human cell lines derived from nine clinically isolated cancer types (leukaemia, lu…

RB1 in cancer: Different mechanisms of RB1 inactivation and alterations of pRb pathway in tumorigenesis.

2013

Loss of RB1 gene is considered either a causal or an accelerating event in retinoblastoma. A variety of mechanisms inactivates RB1 gene, including intragenic mutations, loss of expression by methylation and chromosomal deletions, with effects which are species-and cell type-specific. RB1 deletion can even lead to aneuploidy thus greatly increasing cancer risk. The RB1gene is part of a larger gene family that includes RBL1 and RBL2, each of the three encoding structurally related proteins indicated as pRb, p107, and p130, respectively. The great interest in these genes and proteins springs from their ability to slow down neoplastic growth. pRb can associate with various proteins by which it …