Search results for "Tubulin"

Centrosome structure is very similar in eupyrene and apyrene spermatocytes ofEphestia kuehniella(Pyralidae, Lepidoptera, Insecta)

1997

Summary The higher Lepidoptera produce two types of sperm, eupyrene and apyrene. Eupyrene spermatozoa are fertile, while apyrene spermatozoa are anucleate and, therefore, sterile. Meiosis differs between the two developmental lines. One of the most obvious differences is the aberrant organization of the apyrene spindles. They possess fewer microtubules than eupyrene spindles and chromosome segregation is irregular. To determine whether micotubule nucleation is impaired in the aprene spindles, the present fine structure study concentrated on the centrosomes in both spermatocyte types. In addition, the presence of gamma-tubulin, a newly discovered tubulin isoform which is prevalent in centros…

Abnormal mitotic spindle assembly and cytokinesis induced by D-Limonene in cultured mammalian cells

2013

D-Limonene is found widely in citrus and many other plant species; it is a major constituent of many essential oils and is used as a solvent for commercial purposes. With the discovery of its chemotherapeutic properties against cancer, it is important to investigate the biological effects of the exposure to D-Limonene and elucidate its, as yet unknown, mechanism of action. We reported here that D-Limonene is toxic in V79 Chinese hamster cells in a dose-dependent manner. Moreover, to determine the cellular target of D-Limonene, we performed morphological observations and immunocytochemical analysis and we showed that this drug has a direct effect on dividing cells preventing assembly of mito…

DESIGN AND SYNTHESIS OF NEW QUINAZOLIN-4(3H)-ONE HYBRIDS AS DUAL INHIBITORS OF TUBULIN AND DIHYDROFOLATE REDUCTASE

New strategies are needed for fighting cancer with the goal to improve efficacy of anti-cancer therapy and to limit the onset of drug resistance. Indeed, cancer cells are able to set cellular mechanisms for survival and multiple pathways support their survival. The inhibition of one pathway may then result in the activation of an alternative pathway. One strategy useful for combatting this phenomenon is represented by multi-target drugs. Herein we will present our work aim at identifying new anticancer compounds, which combine dihydrofolate reductase (DHFR) properties with tubulin inhibition. DHFR is a key enzyme involved in the synthesis of raw material for cell proliferation and the inhib…

Intraspecific and within-isolate sequence variation in the ITS rRNA gene region of Pythium mercuriale sp. nov. (Pythiaceae)

2008

Belbahri, Lassaad et al.

In vivo detection of cytokeratin filament network breakdown in cells treated with the phosphatase inhibitor okadaic acid.

2001

We have previously described vulva carcinoma-derived A-431 subclone AK13-1, which stably expresses fluorescently labeled cytokeratin filaments (CKFs). Time-lapse fluorescence microscopy of these cells permits the continuous monitoring of the dynamics of the CKF cytoskeleton in vivo. To study mechanisms and principles of CKF disassembly as it occurs, e.g., during mitosis and liver disease, we have treated cells with the phosphatase inhibitor okadaic acid (OA), which induces complete CKF network breakdown within 3–5 h without significantly affecting the organization of the actin- and tubulin-based cytofilaments. In time-lapse movies, we find that the network breakdown starts at the cell perip…

Synthesis of novel antimitotic agents based on 2-amino-3-aroyl-5-(hetero)arylethynyl thiophene derivatives

2011

Microtubules are dynamic structures that play a crucial role in cellular division and are recognized as an important target for cancer therapy. In search of new compounds with strong antiproliferative activity and simple molecular structure, a new series of 2-amino-3-(3',4',5'-trimethoxybenzoyl)-5-(hetero)aryl ethynyl thiophene derivatives was prepared by the Sonogashira coupling reaction of the corresponding 5-bromothiophenes with several (hetero)aryl acetylenes. When these compounds were analyzed in vitro for their inhibition of cell proliferation, the 2- and 3-thiophenyl acetylene derivatives were the most powerful compounds, both of which exerted cytostatic effects at submicromolar conc…

[1,2]OXAZOLE DERIVATIVES: SYNTHESIS AND BIOLOGICAL EVALUATION AGAINST MULTIPLE MALIGNANT CELL TYPES

2021

Cellular expression of connexins in the rat brain: neuronal localization, effects of kainate-induced seizures and expression in apoptotic neuronal ce…

2003

The identification of connexins (Cxs) expressed in neuronal cells represents a crucial step for understanding the direct communication between neurons and between neuron and glia. In the present work, using a double-labelling method combining in situ hybridization for Cx mRNAs with immunohistochemical detection for neuronal markers, we provide evidence that, among cerebral connexins (Cx26, Cx32, Cx36, Cx37, Cx40, Cx43, Cx45 and Cx47), only Cx45 and Cx36 mRNAs are localized in neuronal cells in both developing and adult rat brain. In order to establish whether connexin expression is influenced in vivo by abnormal neuronal activity, we examined the short-term effects of kainate-induced seizur…

Pyrrolotetrazinones deazaanalogues of temozolomide induce apoptosis in Jurkat cell line: involvement of tubulin polymerization inhibition.

2009

Pyrrolotetrazinones are a new class of azolotetrazinones endowed with a high, remarkable antiproliferative activity in human tumor cultured cells. They hold the deaza skeleton of the antitumor drug temozolomide, although preliminary investigations indicated a different mechanism of action. To understand their mechanism(s) of action along with their target at molecular level, four derivatives were selected on the basis of their activity on a panel of human tumor cell lines and they were investigated in depth in a T leukemia cell line (Jurkat). Flow cytometric analysis of cell cycle after treatment with pyrrolotetrazinones has demonstrated that they were able to induce an arrest of the cell c…

Unique pharmacology of KAR-2, a potential anti-cancer agent: absorption modelling and selective mitotic spindle targeting.

2008

Abstract Bis-indols are a large group of the anti-cancer agents, which effectively arrest the uncontrolled division of the cancerous cells. Their use in clinical chemotherapy is still limited because of: (i) the non-specific targeting of the mitotic cells; (ii) low bioavailability of the drugs. KAR-2 has been identified as a tubulin binding agent which displays significantly lower cytotoxicity but favourable anti-cancer potency than its mother molecule, vinblastine. The objective of this paper, on one hand, was to show that the human intestinal epithelial Caco-2 cells, used for pharmacokinetic studies display distinct sensitivity against KAR-2 and vinblastine due to their distinct targeting…