Wogonin induces G1 phase arrest through inhibiting Cdk4 and cyclin D1 concomitant with an elevation in p21Cip1 in human cervical carcinoma HeLa cells

2009 ◽  
Vol 87 (6) ◽  
pp. 933-942 ◽  
Author(s):  
Li Yang ◽  
Hai-wei Zhang ◽  
Rong Hu ◽  
Yong Yang ◽  
Qi Qi ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Cervical Carcinoma ◽  
Hela Cells ◽  
Therapeutic Potential ◽  
P53 Gene ◽  
Mrna Levels ◽  
Human Cervical Carcinoma ◽  
Phase Arrest

Wogonin, a naturally occurring flavonoid, has been shown to have tumor therapeutic potential both in vitro and in vivo. To better understand its anticancer mechanism, we examined the effect of wogonin on human cervical carcinoma HeLa cells. In this study, we observed that G1 phase arrest was involved in wogonin-induced growth inhibition in HeLa cells. Over a 24 h exposure of HeLa cells to 90 µmol·L–1 wogonin, the promoters of G1–S transition, including cyclin D1/Cdk4 and pRb, decreased within 12 h and E2F-1 depleted in the nucleus at the same time. As the G1 phase arrest developed, p53 and the Cdk inhibitor p21Cip1 elevated both at protein and mRNA levels. Furthermore, the up-regulation of p21Cip1 induced by wogonin was dramatically inhibited by siRNA-mediated p53 gene silencing. Collectively, our data suggested that wogonin induced G1 phase arrest in HeLa cells by modulating several key G1 regulatory proteins, such as Cdk4 and cyclin D1, as well as up-regulation of a p53-midiated p21Cip1 expression. This mechanism of wogonin may play an important role in the killing of cancerous cells and offer a potential mechanism for its anticancer action in vivo.

Repression of cyclin D1: a novel function of MYC

1994 ◽  
Vol 14 (6) ◽  
pp. 4032-4043
Author(s):  
A Philipp ◽  
A Schneider ◽  
I Väsrik ◽  
K Finke ◽  
Y Xiong ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Transcription Initiation ◽  
Core Promoter ◽  
Constitutive Expression ◽  
Mrna Levels ◽  
Amino Terminal ◽  
3T3 Fibroblasts ◽  
Tata Element

Constitutive expression of human MYC represses mRNA levels of cyclin D1 in proliferating BALB/c-3T3 fibroblasts. We expressed a series of mutant alleles of MYC and found that downregulation of cyclin D1 is distinct from previously described properties of MYC. In particular, we found that association with Max is not required for repression of cyclin D1 by MYC in vivo. Conversely, the integrity of a small amino-terminal region (amino acids 92 to 106) of MYC is critical for repression of cyclin D1 but dispensable for transformation of established RAT1A cells. Runoff transcription assays showed that repression occurs at the level of transcription initiation. We cloned the promoter of the gene for human cyclin D1 and found that it lacks a canonical TATA element. Transcription starts at an initiator element similar to that of the adenovirus major late promoter; this element can be directly bound by USF in vitro. Expression of MYC represses the cyclin D1 promoter via core promoter elements and antagonizes USF-mediated transactivation. Taken together, our data define a new pathway for gene regulation by MYC and show that the cyclin D1 gene is a target gene for repression by MYC.

PTD4-apoptin induces Bcl-2-insensitive apoptosis in human cervical carcinoma in vitro and in vivo

2016 ◽  
Vol 27 (10) ◽  
pp. 979-987 ◽  
Author(s):  
Xiao-Wen Liu ◽  
Ping Yuan ◽  
Jun Tian ◽  
Ling-Jun Li ◽  
Yu Wang ◽  
...  
Keyword(s):  
Cervical Carcinoma ◽  
Human Cervical Carcinoma

scholarly journals Overexpression of cyclin D1 in the Dami megakaryocytic cell line causes growth arrest

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 294-304 ◽  
Author(s):  
CC Wilhide ◽  
C Van Dang ◽  
J Dipersio ◽  
AA Kenedy ◽  
PF Bray
Keyword(s):  
Cyclin D1 ◽  
Cell Line ◽  
Cell Lines ◽  
Northern Blotting ◽  
Mrna Levels ◽  
Cyclin Dependent Kinases ◽  
Megakaryocyte Differentiation ◽  
Megakaryocytic Cell

The maturation of megakaryocytes in vivo requires polyploidization or repeated duplication of DNA without cytokinesis. As DNA replication and cytokinesis are tightly regulated in somatic cells by cyclins and cyclin-dependent kinases, we sought to determine the pattern of cyclin gene expression in cells that undergo megakaryocytic differentiation and polyploidization. The Dami megakaryocytic cell line differentiates and increases ploidy in response to phorbol 12-myristate 13-acetate (PMA) stimulation in vitro. We used Northern blotting to analyze mRNA levels of cyclins A, B, C, D1, and E in PMA-induced Dami cells and found that cyclin D1 mRNA levels increased dramatically (18-fold). Similar increases in cyclin D1 mRNA were obtained for other cell lines (HEL and K562) with megakaryocytic properties, but not in HeLa cells. The increase in cyclin D1 was confirmed by Western immunoblotting of PMA-treated Dami cells. This finding suggested that cyclin D1 might participate in megakaryocyte differentiation by promoting endomitosis and/or inhibiting cell division. To address these possibilities, we constructed two stable Zn+2-inducible, cyclin D1-overexpressing Dami cell lines. Cyclin D1 expression alone was not sufficient to induce polyploidy, but in conjunction with PMA-induced differentiation, polyploidization was slightly enhanced. However, unlike other cell systems, cyclin D1 overexpression caused cessation of cell growth. Although the mechanism by which cyclin D1 may affect megakaryocyte differentiation is not clear, these data demonstrate that cyclin D1 is upregulated in differentiating megakaryocytic cells and may contribute to differentiation by arresting cell proliferation.

scholarly journals Connexin 43 confers chemoresistance through activating PI3K

Oncogenesis ◽  
2022 ◽  
Vol 11 (1) ◽  
Author(s):  
Kevin J. Pridham ◽  
Farah Shah ◽  
Kasen R. Hutchings ◽  
Kevin L. Sheng ◽  
Sujuan Guo ◽  
...  
Keyword(s):  
Poor Prognosis ◽  
Connexin 43 ◽  
Therapeutic Potential ◽  
Mrna Levels ◽  
Phosphatidylinositol 3 Kinase ◽  
Junction Protein ◽  
Gap Junction Protein ◽  
Cx43 Mrna

AbstractCircumventing chemoresistance is crucial for effectively treating cancer including glioblastoma, a lethal brain cancer. The gap junction protein connexin 43 (Cx43) renders glioblastoma resistant to chemotherapy; however, targeting Cx43 is difficult because mechanisms underlying Cx43-mediated chemoresistance remain elusive. Here we report that Cx43, but not other connexins, is highly expressed in a subpopulation of glioblastoma and Cx43 mRNA levels strongly correlate with poor prognosis and chemoresistance in this population, making Cx43 the prime therapeutic target among all connexins. Depleting Cx43 or treating cells with αCT1–a Cx43 peptide inhibitor that sensitizes glioblastoma to the chemotherapy temozolomide–inactivates phosphatidylinositol-3 kinase (PI3K), whereas overexpression of Cx43 activates this signaling. Moreover, αCT1-induced chemo-sensitization is counteracted by a PI3K active mutant. Further research reveals that αCT1 inactivates PI3K without blocking the release of PI3K-activating molecules from membrane channels and that Cx43 selectively binds to the PI3K catalytic subunit β (PIK3CB, also called PI3Kβ or p110β), suggesting that Cx43 activates PIK3CB/p110β independent of its channel functions. To explore the therapeutic potential of simultaneously targeting Cx43 and PIK3CB/p110β, αCT1 is combined with TGX-221 or GSK2636771, two PIK3CB/p110β-selective inhibitors. These two different treatments synergistically inactivate PI3K and sensitize glioblastoma cells to temozolomide in vitro and in vivo. Our study has revealed novel mechanistic insights into Cx43/PI3K-mediated temozolomide resistance in glioblastoma and demonstrated that targeting Cx43 and PIK3CB/p110β together is an effective therapeutic approach for overcoming chemoresistance.

scholarly journals Glucocappasalin Induces G2/M-Phase Arrest, Apoptosis, and Autophagy Pathways by Targeting CDK1 and PLK1 in Cervical Carcinoma Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Guangya Xu ◽  
Xueling Yan ◽  
Zhongjia Hu ◽  
Lulu Zheng ◽  
Ke Ding ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cervical Cancer ◽  
Cervical Carcinoma ◽  
Hela Cells ◽  
Carcinoma Cells ◽  
Dependent Manner ◽  
Cycle Arrest ◽  
Phase Arrest ◽  
M Phase

Glucocappasalin (GCP), a natural product derived from the seeds of Descurainia sophia (L.) Webb. ex Prantl, exhibits potential antitumor activity in HeLa cervical carcinoma cells. In this study, we investigated the anti-cervical cancer property of GCP through the induction of cell cycle arrest, apoptosis, and autophagy in vitro and in vivo, and elucidated the underlying molecular mechanisms. We demonstrated that treatment with GCP inhibited the growth of HeLa, Siha, and Ca Ski cell lines in a dose-dependent manner, with HeLa cells displaying particular sensitivity to the GCP treatment. Subsequently, the expression of cyclin-dependent kinase 1 (CDK1) and polo like kinase 1 (PLK1) were evaluated in HeLa cells using the CDK1 kinase assay kit, the fluorescence polarization assay, real-time quantitative PCR, and western blotting. Our results demonstrate that GCP could be employed to attenuate the expression of CDK1 and PLK1 in a dose- and time-dependent manner. The complementary results obtained by flow cytometry and western blotting allowed us to postulate that GCP may exhibit its antitumor effects by inducing G2/M cell cycle arrest. Moreover, HeLa cells treated with GCP exhibited a loss in mitochondrial membrane potential, together with the activation of caspases 3 and 9, and poly ADP-ribose polymerase (PARP). Additionally, we found that GCP could increase the formation of acidic vesicular organelles (AVOs), as well as the levels of Beclin1, LC3-II, p62, and Atg5 proteins in HeLa cells. Further studies indicated that GCP triggered autophagy via the suppression of the PI3K/AKT/mTOR signaling pathways. The autophagy inhibitor 3-methyladenine (3-MA) was used to determine whether autophagy affects the apoptosis induced by GCP. Interestingly, the inhibition of autophagy attenuated apoptosis. In vivo anti-tumor experiments indicated that GCP (60 mg/kg, i.p.) markedly reduced the growth of HeLa xenografts in nude mice without apparent toxicity. Taken together, we demonstrate that GCP induces cell cycle G2/M-phase arrest, apoptosis, and autophagy by acting on the PI3K/AKT/mTOR signaling pathways in cervical carcinoma cells. Thus, GCP may represent a promising agent in the eradication of cervical cancer.

scholarly journals Prognostic and Therapeutic Potential of The OIP5 Network in Papillary Renal Cell Carcinoma

2021 ◽  
Author(s):  
Mathilda Chow ◽  
Yan Gu ◽  
Lizhi He ◽  
Xiaozeng Lin ◽  
Ying Dong ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Therapeutic Potential ◽  
Synthetic Lethality ◽  
Papillary Renal Cell Carcinoma ◽  
Mrna Levels ◽  
Rna Seq

Abstract Background: Papillary renal cell carcinoma (pRCC) is an aggressive but minor type of RCC compared to the main RCC type, clear cell RCC. The current understanding and management of pRCC remain poor. OIP5 possesses oncogenic functions; its contributions to pRCC remain unknown.Methods: OIP5 expression in pRCC at both the protein and mRNA levels was determined using tissue microarray and TCGA dataset. OIP5 was ectopically expressed in metastatic ACHN pRCC cells; xenografts were performed with gene expression profiled by RNA-seq. Differentially expressed genes (DEGs) were analyzed for prognostic potential and impact on pRCC. The effect of PLK1, an OIP5-related DEG, on pRCC tumor growth in vivo was examined.Results: OIP5 expression is upregulated in pRCC. The upregulation associates with pRCC adverse features (T1P<T2P<CIMP, Stage1+2<Stage 3<Stage 4, and N0<N1) and effectively stratifies the fatality risk. OIP5 promotes ACHN pRCC cell proliferation and xenograft formation. RNA-seq reveals network alterations related to immune regulation, metabolism, and hypoxia in ACHN OIP5 tumors compared to empty vector tumors. A set of DEGs was derived from ACHN OIP5 xenografts and primary pRCCs (n=282) contingent to OIP5 upregulation; both DEG sets share 66 overlap genes. Overlap66 effectively predicts overall survival (p<2e-16) and relapse (p<2e-16) possibilities. The prediction is associated with a good out-of-sample performance, supporting its clinical applications. High-risk tumors stratified by Overlap66 risk score possess an immune suppressive environment, evident by elevations in Treg cells and PD1 expression in CD8 T cells. Upregulation of PLK1 occurs in both xenografts and primary pRCC tumors with OIP5 elevations. PLK1 displays a synthetic lethality relationship with OIP5; PLK1 inhibitor BI2356 causes G2/M arrest in ACHN OIP5 cells in vitro and significantly inhibits the growth of xenografts formed by ACHN OIP5 cells in vivo. Conclusions: Our research reveals that OIP5 and its network possess robust prognostic and therapeutic potentials; the prognostic value of Overlap66 and the therapeutic potential of PLK1 inhibitors may pave the way for developing personalized medicine for pRCC management.

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