Provisional bilateral symmetry in Xenopus eggs is estiblished during maturation

Zygote ◽  
1994 ◽  
Vol 2 (3) ◽  
pp. 213-220 ◽  
Author(s):  
E.E. Brown ◽  
K.M. Margelot ◽  
M.V. Danilchik
Keyword(s):  
Cell Cycle ◽  
Bilateral Symmetry ◽  
Entry Point ◽  
Yolk Mass ◽  
Vegetal Cortex ◽  
Sperm Entry ◽  
Egg Cortex ◽  
The Way

SummaryDorsal–ventral patterning in the Xenopus egg becomes established midway through the first cell cycle during a 30° rotation of the subcortical yolk mass relative to the egg cortex. This rotation of symmetrisation is microtubule dependent, and its direction is thought to be cued by the usually eccentric sperm centrosome. The fact that parthenogenetically activated eggs also undergo a directed rotation, despite the absence of a sperm centrosome, suggests that an endogenous asymmetry in the unfertilised egg supports the directed polymerisation of microtubules in the vegetal cortex, in the way that an eccentric sperm centrosome would in fertilised eggs. Consistent with this idea, we noticed that the maturation spot is usually located an average of more than 15° from the geometric centre of the pigmented animal hemisphere. In parthenogenetically activated eggs, this eccentric maturation spot can be used to predict the direction of rotation. Although in most fertilised eggs the yolk mass rotates toward the sperm entry point (SEP) meridian, occasionally this relationship is perturbed significantly; in such eggs, the maturation spot is never on the same side of the egg as the SEP. In oocytes tilted 90° from upright during maturation in vitro, the maturation spot developed 15° or more from the centre of the pigmented hemisphere, always displaced towards the point on the equator that was up during maturation. This experimentally demonstrated lability is consistent with an off-axis oocyte orientation during oogenesis determining its eccentric maturation spot position, and, in turn, its endogenous rotational bias.

Deep cytoplasmic rearrangements during early development in Xenopus laevis

Development ◽  
1991 ◽  
Vol 111 (4) ◽  
pp. 845-856 ◽  
Author(s):  
M.V. Danilchik ◽  
J.M. Denegre
Keyword(s):  
Cell Cycle ◽  
Plasma Membrane ◽  
Xenopus Laevis ◽  
Early Development ◽  
Marginal Zone ◽  
Dorsal Side ◽  
Fluorescent Dye ◽  
Entry Point ◽  
Sperm Entry ◽  
Yolk Platelet

The egg of the frog Xenopus is cylindrically symmetrical about its animal-vegetal axis before fertilization. Midway through the first cell cycle, the yolky subcortical cytoplasm rotates 30 degrees relative to the cortex and plasma membrane, usually toward the side of the sperm entry point. Dorsal embryonic structures always develop on the side away from which the cytoplasm moves. Details of the deep cytoplasmic movements associated with the cortical rotation were studied in eggs vitally stained during oogenesis with a yolk platelet-specific fluorescent dye. During the first cell cycle, eggs labelled in this way develop a complicated swirl of cytoplasm in the animal hemisphere. This pattern is most prominent on the side away from which the vegetal yolk moves, and thus correlates in position with the prospective dorsal side of the embryo. Although the pattern is initially most evident near the egg's equator or marginal zone, extensive rearrangements associated with cleavage furrowing (cytoplasmic ingression) relocate portions of the swirl to vegetal blastomeres on the prospective dorsal side.

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

New Imidazole Inhibitors of Mycobacterial FtsZ: the Way from High-Throughput Molecular Screening in Grid up to in vitro Verification

2016 ◽  
Vol 12 (3) ◽  
pp. 43-55 ◽  
Author(s):  
P.A. Karpov ◽  
◽  
O.M. Demchuk ◽  
V.M. Britsun ◽  
D.I. Lytvyn ◽  
...  
Keyword(s):  
High Throughput ◽  
Molecular Screening ◽  
The Way

OSI-027 alleviates oxaliplatin chemoresistance in gastric cancer cells by suppressing P-gp induction

2020 ◽  
Vol 20 ◽  
Author(s):  
En Xu ◽  
Hao Zhu ◽  
Feng Wang ◽  
Ji Miao ◽  
Shangce Du ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cell Cycle ◽  
Cancer Cells ◽  
Mammalian Target Of Rapamycin ◽  
Cell Counting ◽  
Gastric Cancer Cells ◽  
Ags Cells ◽  
Dual Inhibitor ◽  
Induced Apoptosis

: Gastric cancer is one of the most common malignancies worldwide and the third leading cause of cancer-related death. In the present study, we investigated the potential activity of OSI-027, a potent and selective mammalian target of rapamycin complex 1/2 (mTOR1/2) dual inhibitor, alone or in combination with oxaliplatin against gastric cancer cells in vitro. Cell counting kit-8 assays and EdU staining were performed to examine the proliferation of cancer cells. Cell cycle and apoptosis were detected by flow cytometry. Western blot was used to detect the elements of the mTOR pathway and Pgp in gastric cancer cell lines. OSI-027 inhibited the proliferation of MKN-45 and AGS cells by arresting the cell cycle in the G0/G1 phase. At the molecular level, OSI-027 simultaneously blocked mTORC1 and mTORC2 activation, and resulted in the downregulation of phosphor-Akt, phpspho-p70S6k, phosphor-4EBP1, cyclin D1, and cyclin-dependent kinase4 (CDK4). Additionally, OSI-027 also downregulated P-gp, which enhanced oxaliplatin-induced apoptosis and suppressed multidrug resistance. Moreover, OSI-027 exhibited synergistic cytotoxic effects with oxaliplatin in vitro, while a P-gp siRNA knockdown significantly inhibited the synergistic effect. In summary, our results suggest that dual mTORC1/mTORC2 inhibitors (e.g., OSI-027) should be further investigated as a potential valuable treatment for gastric cancer.

5-Nitro-Thiophene-Thiosemicarbazone Derivatives Present Antitumor Activity Mediated by Apoptosis and DNA Intercalation

2019 ◽  
Vol 19 (13) ◽  
pp. 1075-1091 ◽  
Author(s):  
Karla Mirella Roque Marques ◽  
Maria Rodrigues do Desterro ◽  
Sandrine Maria de Arruda ◽  
Luiz Nascimento de Araújo Neto ◽  
Maria do Carmo Alves de Lima ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Antitumor Activity ◽  
Cell Line ◽  
Mitochondrial Membrane ◽  
In Vitro Cytotoxicity ◽  
Dna Intercalation ◽  
Phase Cell ◽  
Fluorescence Studies ◽  
In Silico Studies

Background: Considering the need for the development of new antitumor drugs, associated with the great antitumor potential of thiophene and thiosemicarbazonic derivatives, in this work we promote molecular hybridization approach to synthesize new compounds with increased anticancer activity. Objective: Investigate the antitumor activity and their likely mechanisms of action of a series of N-substituted 2-(5-nitro-thiophene)-thiosemicarbazone derivatives. Methods: Methods were performed in vitro (cytotoxicity, cell cycle progression, morphological analysis, mitochondrial membrane potential evaluation and topoisomerase assay), spectroscopic (DNA interaction studies), and in silico studies (docking and molecular modelling). Results: Most of the compounds presented significant inhibitory activity; the NCIH-292 cell line was the most resistant, and the HL-60 cell line was the most sensitive. The most promising compound was LNN-05 with IC50 values ranging from 0.5 to 1.9 µg.mL-1. The in vitro studies revealed that LNN-05 was able to depolarize (dose-dependently) the mitochondrial membrane, induceG1 phase cell cycle arrest noticeably, promote morphological cell changes associated with apoptosis in chronic human myelocytic leukaemia (K-562) cells, and presented no topoisomerase II inhibition. Spectroscopic UV-vis and molecular fluorescence studies showed that LNN compounds interact with ctDNA forming supramolecular complexes. Intercalation between nitrogenous bases was revealed through KI quenching and competitive ethidium bromide assays. Docking and Molecular Dynamics suggested that 5-nitro-thiophene-thiosemicarbazone compounds interact against the larger DNA groove, and corroborating the spectroscopic results, may assume an intercalating interaction mode. Conclusion: Our findings highlight 5-nitro-thiophene-thiosemicarbazone derivatives, especially LNN-05, as a promising new class of compounds for further studies to provide new anticancer therapies.

Design, Synthesis and In Vitro Anti-Cancer Evaluation of Novel Derivatives of 2-(2-Methyl-1,5-diaryl-1H-pyrrol-3-yl)-2-oxo-N-(pyridin-3- yl)acetamide

2020 ◽  
Vol 16 (3) ◽  
pp. 340-349
Author(s):  
Ebrahim S. Moghadam ◽  
Farhad Saravani ◽  
Ernest Hamel ◽  
Zahra Shahsavari ◽  
Mohsen Alipour ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Peripheral Neuropathy ◽  
Cell Line ◽  
Normal Cell ◽  
Caspase 3 ◽  
Annexin V ◽  
Normal Cell Line ◽  
Anti Cancer ◽  
Mcf 7

Objective: Several anti-tubulin agents were introduced for the cancer treatment so far. Despite successes in the treatment of cancer, these agents cause toxic side effects, including peripheral neuropathy. Comparing anti-tubulin agents, indibulin seemed to cause minimal peripheral neuropathy, but its poor aqueous solubility and other potential clinical problems have led to its remaining in a preclinical stage. Methods: Herein, indibulin analogues were synthesized and evaluated for their in vitro anti-cancer activity using MTT assay (on the MCF-7, T47-D, MDA-MB231 and NIH-3T3 cell lines), annexin V/PI staining assay, cell cycle analysis, anti-tubulin assay and caspase 3/7 activation assay. Results: One of the compounds, 4a, showed good anti-proliferative activity against MCF-7 cells (IC50: 7.5 μM) and low toxicity on a normal cell line (IC50 > 100 μM). All of the tested compounds showed lower cytotoxicity on normal cell line in comparison to reference compound, indibulin. In the annexin V/PI staining assay, induction of apoptosis in the MCF-7 cell line was observed. Cell cycle analysis illustrated an increasing proportion of cells in the sub-G-1 phase, consistent with an increasing proportion of apoptotic cells. No increase in G2/M cells was observed, consistent with the absence of anti-tubulin activity. A caspase 3/7 assay protocol showed that apoptosis induction by more potent compounds was due to activation of caspase 3. Conclusion: Newly synthesized compounds exerted acceptable anticancer activity and further investigation of current scaffold would be beneficial.

In Vitro Antitumor Evaluation of Some Hybrid Molecules Containing Coumarin and Quinolinone Moieties

2020 ◽  
Vol 19 (16) ◽  
pp. 2010-2018
Author(s):  
Youstina W. Rizzk ◽  
Ibrahim M. El-Deen ◽  
Faten Z. Mohammed ◽  
Moustafa S. Abdelhamid ◽  
Amgad I.M. Khedr
Keyword(s):  
Cell Cycle ◽  
Cell Lines ◽  
Cancer Cell ◽  
Anticancer Agents ◽  
Topoisomerase Ii ◽  
Cancer Cell Lines ◽  
Bax Protein ◽  
Hybrid Molecules ◽  
Mcf 7

Background: Hybrid molecules furnished by merging two or more pharmacophores is an emerging concept in the field of medicinal chemistry and drug discovery. Currently, coumarin hybrids have attracted the keen attention of researchers to discover their therapeutic capability against cancer. Objective: The present study aimed to evaluate the in vitro antitumor activity of a new series of hybrid molecules containing coumarin and quinolinone moieties 4 and 5 against four cancer cell lines. Materials and Methods: A new series of hybrid molecules containing coumarin and quinolinone moieties, 4a-c and 5a-c, were synthesized and screened for their cytotoxicity against prostate PC-3, breast MCF-7, colon HCT- 116 and liver HepG2 cancer cell lines as well as normal breast Hs-371 T. Results: All the synthesized compounds were assessed for their in vitro antiproliferative activity against four cancer cell lines and several compounds were found to be active. Further in vitro cell cycle study of compounds 4a and 5a revealed MCF-7 cells arrest at G2 /M phase of the cell cycle profile and induction apoptosis at pre-G1 phase. The apoptosis-inducing activity was evidenced by up-regulation of Bax protein together with the downregulation of the expression of Bcl-2 protein. The mechanism of cytotoxic activity of compounds 4a and 5a correlated to its topoisomerase II inhibitory activity. Conclusion: Hybrid molecules containing coumarin and quinolinone moieties represents a scaffold for further optimization to obtain promising anticancer agents.

Cyclosporine A Suppresses the Malignant Progression of Oral Squamous Cell Carcinoma in vitro

2019 ◽  
Vol 19 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Ling Gao ◽  
Jianwei Dong ◽  
Nanyang Zhang ◽  
Zhanxian Le ◽  
Wenhao Ren ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Squamous Cell Carcinoma ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Cyclosporine A ◽  
Migration And Invasion ◽  
Signal Molecules ◽  
Cox 2

Background:The Oral Squamous Cell Carcinoma (OSCC) is one of the most frequent cancer types. Failure of treatment of OSCC is potentially lethal because of local recurrence, regional lymph node metastasis, and distant metastasis. Chemotherapy plays a vital role through suppression of tumorigenesis. Cyclosporine A (CsA), an immunosuppressant drug, has been efficiently used in allograft organ transplant recipients to prevent rejection, and also has been used in a subset of patients with autoimmunity related disorders. The present study aims to investigate novel and effective chemotherapeutic drugs to overcome drug-resistance in the treatment of OSCC.Methods:Cells were incubated in the standard way. Cell viability was assayed using the MTT assay. Cell proliferation was determined using colony formation assay. The cell cycle assay was performed using flow cytometry. Apoptosis was assessed using fluorescence-activated cell sorting after stained by the Annexin V-fluorescein isothiocyanate (FITC). Cell migration and invasion were analyzed using wound healing assay and tranwell. The effect of COX-2, c-Myc, MMP-9, MMP-2, and NFATc1 protein expression was determined using Western blot analysis while NFATc1 mRNA expression was determined by RT-PCR.Results:In vitro studies indicated that CsA inhibited partial OSCC growth by inducing cell cycle arrest, apoptosis, and the migration and invasion of OSCC cells. We also demonstrated that CsA could inhibit the expression of NFATc1 and its downstream genes COX-2, c-Myc, MMP-9, and MMP-2 in OSCC cells. Furthermore, we analyzed the expression of NFATc1 in head and neck cancer through the Oncomine database. The data was consistent with the experimental findings.Conclusion:The present study initially demonstrated that CsA could inhibit the progression of OSCC cells and can mediate the signal molecules of NFATc1 signaling pathway, which has strong relationship with cancer development. That explains us CsA has potential to explore the possibilities as a novel chemotherapeutic drug for the treatment of OSCC.

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