scholarly journals Anti-proliferation Effect on Human Breast Cancer Cells via Inhibition of pRb Phosphorylation by Taiwanin E Isolated from Eleutherococcus trifoliatus

2014 ◽  
Vol 9 (9) ◽  
pp. 1934578X1400900
Author(s):  
Hui-Chun Wang ◽  
Yen-Hsueh Tseng ◽  
Hui-Rong Wu ◽  
Fang-Hua Chu ◽  
Yueh-Hsiung Kuo ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Progression ◽  
Kinase Inhibitors ◽  
Folk Medicine ◽  
Breast Adenocarcinoma ◽  
Cyclin D ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Human Breast ◽  
Mcf 7

Eleutherococcus trifoliatus has been used as a folk medicine since ancient times, especially as refreshing qi medicines. In our current study, taiwanin E, which possesses strong cytotoxicity, was isolated from the branches of E. trifoliatus by using a bioactivity guided fractionation procedure. Taiwanin E presented a potent anti-proliferation activity on the growth of a human breast adenocarcinoma cell line (MCF-7), with an IC50 value for cytotoxicity of 1.47 μM. Cell cycle analysis revealed that the proportion of cells in the G0/G1 phase increased in a dose-dependent manner (from 79.4% to 90.2%) after 48 h exposure to taiwanin E at a dosage range from 0.5 to 4μM. After treatment with taiwanin E, phosphorylation of retinoblastoma protein (pRb) in MCF-7 cells was inhibited, accompanied by a decrease in the levels of cyclin D1, cyclin D3 and cyclin-dependent kinase 4 (cdk4) and cdk6; in addition, there was an increase in the expression of cyclin-dependent kinase inhibitors p21WAF-1/Cip1 and p27Kip1. The results suggest that taiwanin E inhibits cell cycle progression of MCF-7 at the G0/G1 transition.

Synthesis and anticancer activity of some pyrido[2,3-d]pyrimidine derivatives as apoptosis inducers and cyclin-dependent kinase inhibitors

2019 ◽  
Vol 11 (18) ◽  
pp. 2395-2414 ◽  
Author(s):  
Safinaz E-S Abbas ◽  
Riham F George ◽  
Eman M Samir ◽  
Mostafa MA Aref ◽  
Hatem A Abdel-Aziz
Keyword(s):  
Cell Cycle ◽  
Anticancer Agents ◽  
Kinase Inhibitors ◽  
Cytotoxic Agents ◽  
Cyclin Dependent Kinase ◽  
Apoptosis Induction ◽  
Pyrimidine Derivatives ◽  
Induced Apoptosis ◽  
Emergence Of Resistance ◽  
Mcf 7

Aim: Due to emergence of resistance to available anticancer agents, there is a need to search for new cytotoxic agents. Methods: Pyrido[2,3- d]pyrimidines (4–6) and their tricyclic derivatives (7–13) were prepared and screened for their cytotoxicity against breast MCF-7, prostate PC-3 and lung A-549 cancer cell lines as well as normal fibroblasts WI-38. Results: The most active compounds were 6b, 6e and 8d compared with doxorubicin. Moreover, compounds 6b and 8d induced apoptosis in PC-3 and MCF-7, respectively via activation of CASP3 (in PC-3 only), Bax, p53 and down regulation of Bcl2 in addition to CDK4/6 inhibition. Conclusion: Pyrido[2,3- d]pyrimidine represents an important core for discovery of new potent cytotoxic agents acting on the cell cycle via apoptosis induction through either intrinsic or extrinsic pathways.

scholarly journals 3-{[(2,3-Dichlorophenyl)amino]methyl}-5-(furan-2-ylmethylidene)-1,3-thiazolidine-2,4-dione

Molbank ◽  
10.3390/m1083 ◽  
2019 ◽  
Vol 2019 (4) ◽  
pp. M1083
Author(s):  
Uwabagira ◽  
Sarojini
Keyword(s):  
Breast Adenocarcinoma ◽  
Cyclin Dependent Kinase ◽  
Human Breast ◽  
Hemolysis Assay ◽  
Human Breast Adenocarcinoma ◽  
Inflammatory Agent ◽  
Human Blood Cell ◽  
Anti Inflammatory ◽  
Mcf 7

The compound 3-{[(2,3-Dichlorophenyl)amino]methyl}-5-(furan-2-ylmethylidene)-1,3-thiazolidine-2,4-dione has been designed, synthesized, and screened for its in vitro antibreast cancer activity, using human breast adenocarcinoma cell lines (MCF-7) and in vitro anti-inflammatory activity. By hemolysis assay, it showed that it has a nonhemolytic and nontoxic effect on human blood cell. The title compound 5, subjected to in vitro activities, showed that it is cytotoxic with an IC50 of 42.30 µM and a good anti-inflammatory agent. The docking results against cyclin dependent kinase 2 (CDK2) (PDB ID: 3QQK) gave insights on its inhibitory activity.

scholarly journals Cyclin F-Chk1 synthetic lethality mediated by E2F1 degradation

2019 ◽  
Author(s):  
Kamila Burdova ◽  
Hongbin Yang ◽  
Roberta Faedda ◽  
Samuel Hume ◽  
Daniel Ebner ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cell Cycle Progression ◽  
Kinase Inhibitors ◽  
Synthetic Lethality ◽  
Checkpoint Inhibitors ◽  
Dependent Manner ◽  
Cycle Progression ◽  
Multiple Substrates ◽  
Cyclin F

SummaryCyclins are central engines of cell cycle progression when partnered with Cyclin Dependent Kinases (CDKs). Among the different cyclins controlling cell cycle progression, cyclin F does not partner with a CDK, but forms an E3 ubiquitin ligase, assembling through the F-box domain, an Skp1-Cul1-F-box (SCF) module. Although multiple substrates of cyclin F have been identified the vulnerabilities of cells lacking cyclin F are not known. Thus, we assessed viability of cells lacking cyclin F upon challenging cells with more than 200 kinase inhibitors. The screen revealed a striking synthetic lethality between Chk1 inhibition and cyclin F loss. Chk1 inhibition in cells lacking cyclin F leads to DNA replication catastrophe. The DNA replication catastrophe depends on the accumulation of E2F1 in cyclin F depleted cells. We observe that SCFcyclin F promotes E2F1 degradation after Chk1 inhibitors in a CDK dependent manner. Thus, Cyclin F restricts E2F1 activity during cell cycle and upon checkpoint inhibition to prevent DNA replication stress. Our findings pave the way for patient selection in the clinical use of checkpoint inhibitors.

Primitive Hematopoietic Cells Resist HIV-1 Infection Via P21Waf1/Cip1/Sdi1.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 490-490
Author(s):  
Jie Lin Zhang ◽  
Clyde S. Crumpacker ◽  
David T. Scadden
Keyword(s):  
Cell Cycle ◽  
Stem Cells ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Hematopoietic Cells ◽  
Surrogate Marker ◽  
Dependent Manner ◽  
Cyclin Dependent Kinase ◽  
Hematopoietic Stem ◽  
Hiv 1

Abstract Hematopoietic stem cells are resistant to HIV-1 infection. We have identified a novel mechanism by which the cyclin-dependent kinase inhibitor, p21Waf1/Cip1/Sdi1 (p21), known for its regulation of stem cell pool size (1,2), restricts HIV-1 infection of primitive hematopoietic cells in a non-cell cycle dependent manner. Knocking down p21 by siRNA increased HIV-1 infection and induction of p21 expression by phorbol ester (TPA) blocked HIV-1 replication. P21 did not affect the overall levels of cDNA synthesis, but significantly blocked viral integration and resulted in marked increase in 2-LTR circles, a surrogate marker of abortive integration. Consistent with these observations, p21 coimmunoprecipitated with viral integrase and both were detected in the preintegration complex (PIC). Furthermore, silencing p27Kip1 and p18INK4C, cyclin dependent kinase inhibitors related to p21 that affect cell cycle, revealed no impact on viral DNA integration. A closely related dual-tropic lentivirus with a distinct integrase, SIVmac-251 and the other cell-intrinsic inhibitors of HIV-1, Trim5a, PML, Murr1, and IFN-a were unaffected by p21. These results indicate a new function for p21, participating in prevention of HIV integration into the cellular genome. Therefore p21 is an endogenous cellular component in stem cells that provides a unique molecular barrier to HIV-1 infection and may explain the basis for these cells being an uninfected ‘sanctuary’ in HIV disease.

scholarly journals Cortactin Modulates RhoA Activation and Expression of Cip/Kip Cyclin-Dependent Kinase Inhibitors To Promote Cell Cycle Progression in 11q13-Amplified Head and Neck Squamous Cell Carcinoma Cells

2010 ◽  
Vol 30 (21) ◽  
pp. 5057-5070 ◽  
Author(s):  
David R. Croucher ◽  
Danny Rickwood ◽  
Carole M. Tactacan ◽  
Elizabeth A. Musgrove ◽  
Roger J. Daly
Keyword(s):  
Cell Cycle ◽  
Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Cell Cycle Progression ◽  
Kinase Inhibitors ◽  
S Phase ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Fadu Cells ◽  
Phase Entry

ABSTRACT The cortactin oncoprotein is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC), often due to amplification of the encoding gene (CTTN). While cortactin overexpression enhances invasive potential, recent research indicates that it also promotes cell proliferation, but how cortactin regulates the cell cycle machinery is unclear. In this article we report that stable short hairpin RNA-mediated cortactin knockdown in the 11q13-amplified cell line FaDu led to increased expression of the Cip/Kip cyclin-dependent kinase inhibitors (CDKIs) p21WAF1/Cip1, p27Kip1, and p57Kip2 and inhibition of S-phase entry. These effects were associated with increased binding of p21WAF1/Cip1 and p27Kip1 to cyclin D1- and E1-containing complexes and decreased retinoblastoma protein phosphorylation. Cortactin regulated expression of p21WAF1/Cip1 and p27Kip1 at the transcriptional and posttranscriptional levels, respectively. The direct roles of p21WAF1/Cip1, p27Kip1, and p57Kip2 downstream of cortactin were confirmed by the transient knockdown of each CDKI by specific small interfering RNAs, which led to partial rescue of cell cycle progression. Interestingly, FaDu cells with reduced cortactin levels also exhibited a significant diminution in RhoA expression and activity, together with decreased expression of Skp2, a critical component of the SCF ubiquitin ligase that targets p27Kip1 and p57Kip2 for degradation. Transient knockdown of RhoA in FaDu cells decreased expression of Skp2, enhanced the level of Cip/Kip CDKIs, and attenuated S-phase entry. These findings identify a novel mechanism for regulation of proliferation in 11q13-amplified HNSCC cells, in which overexpressed cortactin acts via RhoA to decrease expression of Cip/Kip CDKIs, and highlight Skp2 as a downstream effector for RhoA in this process.

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