scholarly journals Structural analysis of the PTEN:P-Rex2 signalling node reveals how cancer-associated mutations coordinate to hyperactivate Rac1

2020 ◽  
Author(s):  
Laura D’Andrea ◽  
Christina M. Lucato ◽  
Elsa A. Marquez ◽  
Yong-Gang Chang ◽  
Srgjan Civciristov ◽  
...  

ABSTRACTThe PTEN:P-Rex2 complex is one of the most commonly mutated signaling nodes in metastatic cancer. Assembly of the PTEN:P-Rex2 complex inhibits the activity of both proteins, and its dysregulation can drive PI3K-AKT signaling and cell proliferation. Here, using extensive crosslinking mass spectrometry and functional studies, we provide crucial mechanistic insights into PTEN:P-Rex2 complex assembly and co-inhibition. PTEN is anchored to P-Rex2 by interactions between the PTEN PDZ-BM tail and the second PDZ domain of P-Rex2. This interaction bridges PTEN across the P-Rex2 surface, occluding PTEN membrane-binding and PI(3,4,5)P3 hydrolysis. Conversely, PTEN both allosterically promotes an autoinhibited P-Rex2 conformation and occludes Gβγ binding and GPCR activation. These insights allow us to define a new gain-of-function class of cancer mutations within the PTEN:P-Rex2 interface that uncouples PTEN inhibition of Rac1 signaling. These findings provide a mechanistic framework to understand the dysregulation of the PTEN:P-Rex2 signaling node in metastatic cancer.

2019 ◽  
Vol 39 (6) ◽  
Author(s):  
Hongying Zhao ◽  
Yu Wang ◽  
Xiubao Ren

Abstract Objective: Nicotine, the main ingredient in tobacco, is identified to facilitate tumorigenesis and accelerate metastasis in tumor. Studies in recent years have reported that long intergenic non-protein coding RNA 460 (LINC00460) is strongly associated with lung cancer poor prognosis and nicotine dependence. Nonetheless, it is unclear whether nicotine promotes the development of lung cancer through activation of LINC00460. Methods: We determined that LINC00460 expression in lung cancer tissues and the prognosis in patients with non-small cell lung carcinoma (NSCLC) using Gene Expression Profiling Interactive Analysis (GEPIA) website and The Cancer Genome Atlas (TCGA) database. Through in vitro experiments, we studied the effects of nicotine on LINC00460 in NSCLC cells lines using Cell Counting Kit-8 (CCK-8), transwell test, flow cytometry, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blot assays. Results: We identified the significant up-regulated expression level of LINC00460 in NSCLC tissues and cell lines, especially, the negative correlation of LINC00460 expression level with overall survival (OS). In in vitro experiments, LINC00460 was overexpressed in NSCLC cell lines under nicotine stimulation. Nicotine could relieve the effect of LINC00460 knockdown on NSCLC cell proliferation, migration and apoptosis. The same influence was observed on PI3K/Akt signaling pathway. Conclusions: In summary, this is the first time to examine the potential roles of LINC00460 in lung cancer cell proliferation, migration and apoptosis induced by nicotine. This may help to develop novel therapeutic strategies for the prevention and treatment of metastatic tumors from cigarette smoke-caused lung cancer by blocking the nicotine-activated LINC00460 pathway.


Tumor Biology ◽  
2014 ◽  
Vol 35 (5) ◽  
pp. 4095-4099 ◽  
Author(s):  
Lu Zheng ◽  
Wei Gong ◽  
Ping Liang ◽  
XiaoBing Huang ◽  
Nan You ◽  
...  

PLoS Genetics ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. e1003253 ◽  
Author(s):  
Renee D. Read ◽  
Tim R. Fenton ◽  
German G. Gomez ◽  
Jill Wykosky ◽  
Scott R. Vandenberg ◽  
...  

2008 ◽  
Vol 86 (13) ◽  
pp. 2820-2828 ◽  
Author(s):  
Hideyuki Migita ◽  
Katsuya Kominami ◽  
Mami Higashida ◽  
Rumi Maruyama ◽  
Nobuko Tuchida ◽  
...  

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dongyong Yang ◽  
Yanqing Wang ◽  
Yajing Zheng ◽  
Fangfang Dai ◽  
Shiyi Liu ◽  
...  

Abstract Background Polycystic ovary syndrome (PCOS) is the most common hormonal disorder among reproductive-aged women worldwide, however, the mechanisms and progression of PCOS still unclear due to its heterogeneous nature. Using the human granulosa-like tumor cell line (KGN) and PCOS mice model, we explored the function of lncRNA UCA1 in the pathological progression of PCOS. Results CCK8 assay and Flow cytometry were used to do the cell cycle, apoptosis and proliferation analysis, the results showed that UCA1 knockdown in KGN cells inhibited cell proliferation by blocking cell cycle progression and promoted cell apoptosis. In the in vivo experiment, the ovary of PCOS mice was injected with lentivirus carrying sh-UCA1, the results showed that knockdown of lncRNA UCA1 attenuated the ovary structural damage, increased the number of granular cells, inhibited serum insulin and testosterone release, and reduced the pro-inflammatory cytokine production. Western blot also revealed that UCA1 knockdown in PCOS mice repressed AKT activation, inhibitor experiment demonstrated that suppression of AKT signaling pathway, inhibited the cell proliferation and promoted apoptosis. Conclusions Our study revealed that, in vitro, UCA1 knockdown influenced the apoptosis and proliferation of KGN cells, in vivo, silencing of UCA1 regulated the ovary structural damage, serum insulin release, pro-inflammatory production, and AKT signaling pathway activation, suggesting lncRNA UCA1 plays an important role in the pathological progression of PCOS.


2021 ◽  
Vol 11 (9) ◽  
pp. 1785-1791
Author(s):  
Tangpeng Xu ◽  
Changli Ruan ◽  
Xu Bin ◽  
Mengxue Hu

Hepatocellular carcinoma (HCC) is a serious threat to human health. miR-340 participates in HCC pathogenesis, but its specific mechanism is not completely clear. Therefore, our study assessed the mechanism by how miR-340 involves in HCC. The cancer tissues and paracancerous tissues of HCC patients were collected. miR-340 mimics/NC and Akt siRNA were transfected into HepG2 cells followed by analysis of miR-304 and EMT-related molecules expression by Real-time PCR, cell invasion and migration by Transwell assay, cell proliferation ability by CCK8 assay as well as p-Akt and p-mTOR level by Western blot. miR-340 in HCC tissues was significantly downregulated compared to adjacent tissues (P <0.001). With increased pathological grade, miR-340 expression was decreased gradually. p-Akt and p-mTOR in HCC tissues was significantly upregulated and elevated gradually with increased pathological grade. p-Akt and p-mTOR was negatively associated with miR-340 (P <0.001). After overexpression of miR-340, HepG2 cell proliferation, invasion, migration and epithelialization were significantly inhibited, and p-Akt and p-mTOR was reduced. When Akt expression was interfered with siRNA, cell proliferation and epithelialization was further inhibited. miR-340 inhibits the development of hepatocellular carcinoma through Akt signaling pathway.


2018 ◽  
Vol 17 (7) ◽  
pp. 1243
Author(s):  
Fen Wen ◽  
Yuxian Lu ◽  
Ke Xu ◽  
Yanmei Liu ◽  
Xiaojuan Qian ◽  
...  

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