scholarly journals The CDK inhibitor SIAMESE targets both CDKA;1 and CDKB1 complexes to establish endoreplication in trichomes

2020 ◽  
Author(s):  
Kai Wang ◽  
Ruth Ndathe ◽  
Narender Kumar ◽  
Elizabeth A. Zeringue ◽  
Naohiro Kato ◽  
...  
Keyword(s):  
Stress Responses ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Binding Motif ◽  
Cdk Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Binding Partner ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Conflicting Evidence

AbstractEndoreplication, also known as endoreduplication, is a modified cell cycle in which DNA is replicated without subsequent cell division. Endoreplication plays important roles in both normal plant development and in stress responses. The SIAMESE (SIM) gene of Arabidopsis (Arabidopsis thaliana) encodes a cyclin-dependent kinase inhibitor that plays an central role in establishing endoreplication, and is the founding member of the SIAMESE-RELATED (SMR) family of plant-specific cyclin-dependent kinase inhibitors genes. However, there has been conflicting evidence regarding which specific cyclin/CDK complexes are inhibited by SIM in vivo. In this work, we use genetic evidence to show that SIM likely inhibits both CDKA;1- and CDKB1-containing CDK complexes in vivo to promote endoreplication in developing Arabidopsis trichomes. We also show that SIM interacts with CYCA2;3, a binding partner of CDKB1;1, via SIM Motif A, which we previously identified as a CDK-binding motif. In contrast, SIM Motif C, which has been indicated as a cyclin binding motif in other contexts, appears to be relatively unimportant for interaction between SIM and CYCA2;3. Together with earlier results, our work suggests that SIM and other SMRs likely have a multivalent interaction with CYC/CDK complexes.One sentence summaryThe cyclin-dependent kinase inhibitor SIAMESE (SIM) targets both CDKA;1 and CDKB1 complexes to establish endoreplication, and that SIM interacts with the cyclin CYCA2;3 via SIM Motif A.

scholarly journals Negative Regulation of ASK1 by p21Cip1 Involves a Small Domain That Includes Serine 98 That Is Phosphorylated by ASK1 In Vivo

2007 ◽  
Vol 27 (9) ◽  
pp. 3530-3541 ◽  
Author(s):  
Jun Zhan ◽  
John B. Easton ◽  
Shile Huang ◽  
Ashutosh Mishra ◽  
Limin Xiao ◽  
...  
Keyword(s):  
Kinase Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Cellular Functions ◽  
Terminal Protein ◽  
Jnk Pathway ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Small Domain ◽  
Cellular Stresses

ABSTRACT The cyclin-dependent kinase inhibitor p21Cip1 regulates multiple cellular functions and protects cells from genotoxic and other cellular stresses. Activation of apoptosis signal-regulating kinase 1 (ASK1) induced by inhibition of mTOR signaling leads to sustained phospho-c-Jun that is suppressed in cells with functional p53 or by forced expression of p21Cip1. Here we show that small deletions of p21Cip1 around S98 abrogate its association with ASK1 but do not affect binding to Cdk1, hence distinguishing between the cell cycle-regulating functions of p21Cip1 and its ability to suppress activation of the ASK1/Jun N-terminal protein kinase (JNK) pathway. p21Cip1 is phosphorylated in vitro by both ASK1 and JNK1 at S98. In vivo phosphorylation of p21Cip1, predominantly carried out by ASK1, is associated with binding to ASK1 and inactivation of ASK1 kinase function. Binding of p21Cip1 to ASK1 requires ASK1 kinase function and may involve phosphorylation of S98.

Phase IIa safety and efficacy of milciclib, a pan-cyclin dependent kinase inhibitor, in unresectable, sorafenib-refractory or -intolerant hepatocellular carcinoma patients.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e16711-e16711
Author(s):  
Erica Villa ◽  
Fabio Piscaglia ◽  
Rabit Geva ◽  
George Dalecos ◽  
George Papatheodoridis ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Checkpoint Inhibitors ◽  
Primary Objective ◽  
Response To Treatment ◽  
Cyclin Dependent Kinase ◽  
Advanced Hcc ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Secondary Endpoints

e16711 Background: Current hepatocellular carcinoma (HCC) therapeutics, tyrosine kinase inhibitors (TKI) and checkpoint inhibitors (CI), provide limited improvement in overall survival, suggesting the need to identify drugs with broad-spectrum mechanisms of action, used alone or in combination with a TKI or CI. Milciclib, a pan cyclin dependent kinase inhibitor, exhibited anti-cancer activity in refractory solid malignancy patients. The primary objective of this trial was to evaluate safety and tolerability of milciclib in sorafenib-refractory or intolerant advanced HCC patients. Methods: Single arm and multi-center study in advanced HCC patients was conducted in Italy, Greece and Israel. Milciclib was administered orally for up to 6 cycles. Each cycle consisted of 100mg milciclib daily for 4d on/3d off/week for 4 weeks. Safety assessment was the primary endpoint and secondary endpoints included progression free survival (PFS), time to progression (TTP) and clinical benefit rate (CBR). Results: A total of 31 patients were enrolled and 28 were evaluable for efficacy, of which 14 (50%) completed 6-months of treatment. Milciclib was well-tolerated with manageable toxicities. Eighteen of 31 treated patients had drug-related adverse events (AEs) with most frequent (≥5%) occurrence of drug-related diarrhea, nausea, asthenia, fatigue, retinal hemorrhage, rash and myalgia. No drug-related deaths were recorded. Nine of 14 patients (64%) continued treatment under Compassionate Use after study completion. Seven patients received milciclib until 9, 9, 10, 11, 13, 13 and 16 months. The remaining 2 patients are in the 16th month of treatment. Clinical response to treatment, assessed by mRECIST (independent radiological review), is shown in the Table. Both median TTP and PFS were 5.9 months. Conclusions: Milciclib, acting via a new mechanism, was safe, well-tolerated and met primary and secondary endpoints with 61% CBR. These promising clinical data warrant further evaluation of milciclib. Clinical trial information: NCT03109886 . [Table: see text]

scholarly journals Therapeutic targeting of tumor-associated myeloid cells synergizes with radiation therapy for glioblastoma

2019 ◽  
Vol 116 (47) ◽  
pp. 23714-23723 ◽  
Author(s):  
Peng Zhang ◽  
Jason Miska ◽  
Catalina Lee-Chang ◽  
Aida Rashidi ◽  
Wojciech K. Panek ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Clinical Response ◽  
Kinase Inhibitor ◽  
Myeloid Cells ◽  
Cyclin Dependent Kinase ◽  
Therapeutic Modalities ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Programmed Death ◽  
Immense Potential

Tumor-associated myeloid cells (TAMCs) are key drivers of immunosuppression in the tumor microenvironment, which profoundly impedes the clinical response to immune-dependent and conventional therapeutic modalities. As a hallmark of glioblastoma (GBM), TAMCs are massively recruited to reach up to 50% of the brain tumor mass. Therefore, they have recently been recognized as an appealing therapeutic target to blunt immunosuppression in GBM with the hope of maximizing the clinical outcome of antitumor therapies. Here we report a nano-immunotherapy approach capable of actively targeting TAMCs in vivo. As we found that programmed death-ligand 1 (PD-L1) is highly expressed on glioma-associated TAMCs, we rationally designed a lipid nanoparticle (LNP) formulation surface-functionalized with an anti–PD-L1 therapeutic antibody (αPD-L1). We demonstrated that this system (αPD-L1-LNP) enabled effective and specific delivery of therapeutic payload to TAMCs. Specifically, encapsulation of dinaciclib, a cyclin-dependent kinase inhibitor, into PD-L1–targeted LNPs led to a robust depletion of TAMCs and an attenuation of their immunosuppressive functions. Importantly, the delivery efficiency of PD-L1–targeted LNPs was robustly enhanced in the context of radiation therapy (RT) owing to the RT-induced up-regulation of PD-L1 on glioma-infiltrating TAMCs. Accordingly, RT combined with our nano-immunotherapy led to dramatically extended survival of mice in 2 syngeneic glioma models, GL261 and CT2A. The high targeting efficiency of αPD-L1-LNP to human TAMCs from GBM patients further validated the clinical relevance. Thus, this study establishes a therapeutic approach with immense potential to improve the clinical response in the treatment of GBM and warrants a rapid translation into clinical practice.

The p21 cyclin–dependent kinase inhibitor suppresses tumorigenicity in vivo

1995 ◽  
Vol 1 (10) ◽  
pp. 1052-1056 ◽  
Author(s):  
Zhi-Yong Yang ◽  
Neil D. Perkins ◽  
Takeshi Ohno ◽  
Elizabeth G. Nabel ◽  
Gary J. Nabel
Keyword(s):  
Kinase Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Cyclin Dependent Kinase Inhibitor

scholarly journals Alsterpaullone, a Cyclin-Dependent Kinase Inhibitor, Mediated Toxicity in HeLa Cells through Apoptosis-Inducing Effect

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Chunying Cui ◽  
Yuji Wang ◽  
Yaonan Wang ◽  
Ming Zhao ◽  
Shiqi Peng
Keyword(s):  
Cell Cycle ◽  
Hela Cells ◽  
Cell Cycle Progression ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Cdk Inhibitor ◽  
Cyclin Dependent Kinase ◽  
Cycle Progression ◽  
Cyclin Dependent Kinase Inhibitor ◽  
Dose Dependent

Alsterpaullone, a small molecule cyclin-dependent kinase (CDK) inhibitor, regulates the cell cycle progression. Beyond death-inducing properties, we identified the effect of alsterpaullone on cycle procedure and apoptosis of HeLa cell. It was found that alsterpaullone inhibited HeLa cells in a time-dependent (0–72 h) and dose-dependent (0–30 μM) manner. In the presence of alsterpaullone, HeLa cells were arrested in G2/M prior to undergoing apoptosis via a mechanism that is involved in the regulation of various antiapoptotic genes, DNA-repair, transcription, and cell cycle progression. Compared to controls, alsterpaullone effectively prevented HeLa cells from entering S-phase. These potential therapeutic efficacies could be correlated with the activation of caspase-3.

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