Faculty Opinions recommendation of Exo70p mediates the secretion of specific exocytic vesicles at early stages of the cell cycle for polarized cell growth.

Author(s):  
Mark Rose
2007 ◽  
Vol 176 (6) ◽  
pp. 771-777 ◽  
Author(s):  
Bing He ◽  
Fengong Xi ◽  
Jian Zhang ◽  
Daniel TerBush ◽  
Xiaoyu Zhang ◽  
...  

In budding yeast, two classes of post-Golgi secretory vesicles carrying different sets of cargoes typified by Bgl2p and invertase are delivered to the plasma membrane for secretion. The exocyst is implicated in tethering these vesicles to the daughter cell membrane for exocytosis. In this study, we report that mutations in the exocyst component Exo70p predominantly block secretion of the Bgl2p vesicles. Furthermore, a defect in invertase vesicle trafficking caused by vps1Δ or pep12Δ in the exo70 mutant background is detrimental to the cell. The secretion defect in exo70 mutants was most pronounced during the early budding stage, which affected daughter cell growth. The selective secretion block does not occur at the vesicle formation or sorting stage because the exocytic vesicles are properly generated and protein processing is normal in the exo70 mutants. Our study suggests that Exo70p functions primarily at early stages of the cell cycle in Bgl2p vesicle secretion, which is critical for polarized cell growth.


2020 ◽  
Vol 19 (16) ◽  
pp. 2019-2033 ◽  
Author(s):  
Pratibha Pandey ◽  
Mohammad H. Siddiqui ◽  
Anu Behari ◽  
Vinay K. Kapoor ◽  
Kumudesh Mishra ◽  
...  

Background: The aberrant alteration in Jab1 signalosome (COP9 Signalosome Complex Subunit 5) has been proven to be associated with the progression of several carcinomas. However the specific role and mechanism of action of Jab1 signalosome in carcinogenesis of gall bladder cancer (GBC) are poorly understood. Objective: The main objective of our study was to elucidate the role and mechanism of Jab1 signalosome in gall bladder cancer by employing siRNA. Methods: Jab1 overexpression was identified in gall bladder cancer tissue sample. The role of Jab1-siRNA approach in cell growth inhibition and apoptotic induction was then examined by RT-PCR, Western Blotting, MTT, ROS, Hoechst and FITC/Annexin-V staining. Results: In the current study, we have shown that overexpression of Jab1 stimulated the proliferation of GBC cells; whereas downregulation of Jab1 by using Jab1-siRNA approach resulted incell growth inhibition and apoptotic induction. Furthermore, we found that downregulation of Jab1 induces cell cycle arrest at G1 phase and upregulated the expression of p27, p53 and Bax gene. Moreover, Jab1-siRNA induces apoptosis by enhancing ROS generation and caspase-3 activation. In addition, combined treatment with Jab1-siRNA and gemicitabine demonstrated an enhanced decline in cell proliferation which further suggested increased efficacy of gemcitabine at a very lower dose (5μM) in combination with Jab1-siRNA. Conclusion: In conclusion, our study strongly suggests that targeting Jab1 signalosome could be a promising therapeutic target for the treatment of gall bladder cancer.


2019 ◽  
Vol 19 (14) ◽  
pp. 1728-1736
Author(s):  
Xuefeng Liu ◽  
Yonggang Fan ◽  
Jing Xie ◽  
Li Zhang ◽  
Lihua Li ◽  
...  

Background:The 12-hydroxy-14-dehydroandrographolide (DP) is a predominant component of the traditional herbal medicine Andrographis paniculata (Burm. f.) Nees (Acanthaceae). Recent studies have shown that DP exhibits potent anti-cancer effects against oral and colon cancer cells.Objective:This investigation examined the potential effects of DP against osteosarcoma cell.Methods:A cell analyzer was used to measure cell viability. The cell growth and proliferation were performed by Flow cytometry and BrdU incorporation assay. The cell migration and invasion were determined by wound healing and transwell assay. The expression of EMT related proteins was examined by Western blot analysis.Results:In this study, we found that DP treatment repressed osteosarcoma (OS) cell growth in a dose-dependent manner. DP treatment significantly inhibited OS cell proliferation by arresting the cell cycle at G2/M phase. In addition, DP treatment effectively inhibited the migration and invasion abilities of OS cells through wound healing and Transwell tests. Mechanistic studies revealed that DP treatment effectively rescued the epithelialmesenchymal transition (EMT), while forced expression of SATB2 in OS cells markedly reversed the pharmacological effect of DP on EMT.Conclusion:Our data demonstrated that DP repressed OS cell growth through inhibition of proliferation and cell cycle arrest; DP also inhibited metastatic capability of OS cells through a reversal of EMT by targeting SATB2. These findings demonstrate DP’s potential as a therapeutic drug for OS treatment.


BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jinhong Qi ◽  
Li Zhou ◽  
Dongqing Li ◽  
Jingyuan Yang ◽  
He Wang ◽  
...  

Abstract Background Cell division cycle 25A (CDC25A) is a well-recognized regulator of cell cycle progression and is involved in cancer development. This work focused on the function of CDC25A in cervical cancer cell growth and the molecules involved. Methods A GEO dataset GSE63514 comprising data of cervical squamous cell carcinoma (CSCC) tissues was used to screen the aberrantly expressed genes in cervical cancer. The CDC25A expression in cancer and normal tissues was predicted in the GEPIA database and that in CSCC and normal cells was determined by RT-qPCR and western blot assays. Downregulation of CDC25A was introduced in CSCC cells to explore its function in cell growth and the cell cycle progression. The potential regulators of CDC25A activity and the possible involved signaling were explored. Results CDC25A was predicted to be overexpressed in CSCC, and high expression of CDC25A was observed in CSCC cells. Downregulation of CDC25A in ME180 and C33A cells reduced cell proliferation and blocked cell cycle progression, and it increased cell apoptosis. ALX3 was a positive regulator of CDC25A through transcription promotion. It recruited a histone demethylase, lysine demethylase 2B (KDM2B), to the CDC25A promoter, which enhanced CDC25A expression through demethylation of H3k4me3. Overexpression of ALX3 in cells blocked the inhibitory effects of CDC25A silencing. CDC25A was found as a positive regulator of the PI3K/Akt signaling pathway. Conclusion This study suggested that the ALX3 increased CDC25A expression through KDM2B-mediated demethylation of H3K4me3, which induced proliferation and cell cycle progression of cervical cancer cells.


2000 ◽  
Vol 20 (1) ◽  
pp. 233-241 ◽  
Author(s):  
Zhengming Gu ◽  
Cathy Flemington ◽  
Thomas Chittenden ◽  
Gerard P. Zambetti

ABSTRACT DNA damage and/or hyperproliferative signals activate the wild-type p53 tumor suppressor protein, which induces a G1 cell cycle arrest or apoptosis. Although the mechanism of p53-mediated cell cycle arrest is fairly well defined, the p53-dependent pathway regulating apoptosis is poorly understood. Here we report the functional characterization of murine ei24 (also known asPIG8), a gene directly regulated by p53, whose overexpression negatively controls cell growth and induces apoptotic cell death. Ectopic ei24 expression markedly inhibits cell colony formation, induces the morphological features of apoptosis, and reduces the number of β-galactosidase-marked cells, which is efficiently blocked by coexpression of Bcl-XL. Theei24/PIG8 gene is localized on human chromosome 11q23, a region frequently altered in human cancers. These results suggest that ei24 may play an important role in negative cell growth control by functioning as an apoptotic effector of p53 tumor suppressor activities.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
E. De Luna-Bertos ◽  
J. Ramos-Torrecillas ◽  
O. García-Martínez ◽  
L. Díaz-Rodríguez ◽  
C. Ruiz

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in bone tissue repair treatment for their pharmacological action. The objective of this study was to determine the effect of aspirin, on osteoblast growth, using MG63 cell line as osteoblast model. MTT spectrophotometry results showed that 20, 100, and 1000 μM aspirin doses have an inhibitory effect on growth. Cell cycle analysis revealed that aspirin doses of 100 and 1000 μM arrest the cell cycle in phase GO/G1. Parallel apoptosis/necrosis studies showed no changes in comparison to control cells after treatment with 1 or 10 μM aspirin but a significantly increased percentage of cells in apoptosis at doses of 20, 100, and 1000 μM. We highlight that treatment of osteoblast-like cells with 1000 μM aspirin increased not only the percentage of cells in apoptosis but also the percentage of necrotic cells, which was not observed in aspirin treatments at lower doses.


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