scholarly journals Effect of the Serum Inhibited Gene (Si1) on Autophagy and Apoptosis in MCF-7 Breast Cancer Cells

2017 ◽  
Vol 41 (6) ◽  
pp. 2268-2278 ◽  
Author(s):  
Yu Li ◽  
Yong Cui ◽  
Wenxue Wang ◽  
Mingxing Ma ◽  
Meizhang Li ◽  
...  

Background/Aims: The serum inhibited gene (Si1) was named according to its inhibited expression in response to serum exposure. Si1 has an important relationship with tumors. Autophagy and apoptosis are two types of cell death. However, there are few studies regarding the association between Si1 and autophagy, or apoptosis in tumors. In this, we investigated the effect of Si1 on the proliferation and cell cycle progression of MCF-7 cells and its influence on autophagy and apoptosis in MCF-7 cells. Methods: To investigate these functions of Si1 in tumor cells, we firstly constructed a pEGFP-Si1 overexpression vector and a pSilencer-Si1 interference vector, and we subsequently tested the proliferation and cell cycle progression of MCF-7 cells using the MTT assay and flow cytometry, and we then detected autophagy by western blotting and MDC (Monodansylcadaverine) staining as well as apoptosis by western blotting and Hoechst 33258 staining. Results: We found that the Si1 gene can significantly inhibit the viability of MCF-7 cells and arrest the cell cycle at the G2/M phase. Si1 can induce autophagy through upregulation of LC3-II and Beclin1, it can induce apoptosis through cleavage of PARP in MCF-7 cells. Conclusion: Altogether, our study indicated that Si1 can inhibit cell proliferation of MCF-7, and also induces autophagy and apoptosis. This study firstly investigated the effect of Si1 on autophagy and apoptosis in MCF-7 cells. Moreover, it also improves the current understanding of the mechanisms related to the effect of Si1 on tumor cells and also provides a foundation for gene-targeted therapy.

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Elliot C Woods ◽  
FuiBoon Kai ◽  
J Matthew Barnes ◽  
Kayvon Pedram ◽  
Michael W Pickup ◽  
...  

Metastasis depends upon cancer cell growth and survival within the metastatic niche. Tumors which remodel their glycocalyces, by overexpressing bulky glycoproteins like mucins, exhibit a higher predisposition to metastasize, but the role of mucins in oncogenesis remains poorly understood. Here we report that a bulky glycocalyx promotes the expansion of disseminated tumor cells in vivo by fostering integrin adhesion assembly to permit G1 cell cycle progression. We engineered tumor cells to display glycocalyces of various thicknesses by coating them with synthetic mucin-mimetic glycopolymers. Cells adorned with longer glycopolymers showed increased metastatic potential, enhanced cell cycle progression, and greater levels of integrin-FAK mechanosignaling and Akt signaling in a syngeneic mouse model of metastasis. These effects were mirrored by expression of the ectodomain of cancer-associated mucin MUC1. These findings functionally link mucinous proteins with tumor aggression, and offer a new view of the cancer glycocalyx as a major driver of disease progression.


PLoS ONE ◽  
2014 ◽  
Vol 9 (12) ◽  
pp. e116048 ◽  
Author(s):  
Hitomi Hasegawa ◽  
Kenichi Ishibashi ◽  
Shoichi Kubota ◽  
Chihiro Yamaguchi ◽  
Ryuzaburo Yuki ◽  
...  

Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3327
Author(s):  
Zhixiang Wang

The cell cycle is the series of events that take place in a cell, which drives it to divide and produce two new daughter cells. The typical cell cycle in eukaryotes is composed of the following phases: G1, S, G2, and M phase. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that control the activity of various Cdk–cyclin complexes. While the mechanism underlying the role of growth factor signaling in G1 phase of cell cycle progression has been largely revealed due to early extensive research, little is known regarding the function and mechanism of growth factor signaling in regulating other phases of the cell cycle, including S, G2, and M phase. In this review, we briefly discuss the process of cell cycle progression through various phases, and we focus on the role of signaling pathways activated by growth factors and their receptor (mostly receptor tyrosine kinases) in regulating cell cycle progression through various phases.


2005 ◽  
Vol 25 (13) ◽  
pp. 5725-5737 ◽  
Author(s):  
Kazuhiro Katayama ◽  
Naoya Fujita ◽  
Takashi Tsuruo

ABSTRACT The serine/threonine kinase Akt is known to promote cell growth by regulating the cell cycle in G1 phase through activation of cyclin/Cdk kinases and inactivation of Cdk inhibitors. However, how the G2/M phase is regulated by Akt remains unclear. Here, we show that Akt counteracts the function of WEE1Hu. Inactivation of Akt by chemotherapeutic drugs or the phosphatidylinositide-3-OH kinase inhibitor LY294002 induced G2/M arrest together with the inhibitory phosphorylation of Cdc2. Because the increased Cdc2 phosphorylation was completely suppressed by wee1hu gene silencing, WEE1Hu was associated with G2/M arrest induced by Akt inactivation. Further analyses revealed that Akt directly bound to and phosphorylated WEE1Hu during the S to G2 phase. Serine-642 was identified as an Akt-dependent phosphorylation site. WEE1Hu kinase activity was not affected by serine-642 phosphorylation. We revealed that serine-642 phosphorylation promoted cytoplasmic localization of WEE1Hu. The nuclear-to-cytoplasmic translocation was mediated by phosphorylation-dependent WEE1Hu binding to 14-3-3θ but not 14-3-3β or -σ. These results indicate that Akt promotes G2/M cell cycle progression by inducing phosphorylation-dependent 14-3-3θ binding and cytoplasmic localization of WEE1Hu.


2020 ◽  
Vol 21 (23) ◽  
pp. 9166
Author(s):  
Shigeru Hanamata ◽  
Takamitsu Kurusu ◽  
Kazuyuki Kuchitsu

Autophagy is ubiquitous in eukaryotic cells and plays an essential role in stress adaptation and development by recycling nutrients and maintaining cellular homeostasis. However, the dynamics and regulatory mechanisms of autophagosome formation during the cell cycle in plant cells remain poorly elucidated. We here analyzed the number of autophagosomes during cell cycle progression in synchronized tobacco BY-2 cells expressing YFP-NtATG8a as a marker for the autophagosomes. Autophagosomes were abundant in the G2 and G1 phases of interphase, though they were much less abundant in the M and S phases. Autophagosomes drastically decreased during the G2/M transition, and the CDK inhibitor roscovitine inhibited the G2/M transition and the decrease in autophagosomes. Autophagosomes were rapidly increased by a proteasome inhibitor, MG-132. MG-132-induced autophagosome formation was also markedly lower in the M phases than during interphase. These results indicate that the activity of autophagosome formation is differently regulated at each cell cycle stage, which is strongly suppressed during mitosis.


2004 ◽  
Vol 19 (3) ◽  
pp. 321 ◽  
Author(s):  
Sarah Yoon ◽  
Jin Young Lee ◽  
Byung-Koo Yoon ◽  
DukSoo Bae ◽  
DooSeok Choi

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