scholarly journals AKT1-CREB stimulation of PDGFRα expression is pivotal for PTEN deficient tumor development

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Xiaofeng Wan ◽  
Meng Zhou ◽  
Fuqiang Huang ◽  
Na Zhao ◽  
Xu Chen ◽  
...  

AbstractAs evidenced by the behavior of loss-of-function mutants of PTEN in the context of a gain-of-function mutation of AKT1, the PTEN-AKT1 signaling pathway plays a critical role in human cancers. In this study, we demonstrated that a deficiency in PTEN or activation of AKT1 potentiated the expression of platelet-derived growth factor receptor α (PDGFRα) based on studies on Pten−/− mouse embryonic fibroblasts, human cancer cell lines, the hepatic tissues of Pten conditional knockout mice, and human cancer tissues. Loss of PTEN enhanced PDGFRα expression via activation of the AKT1-CREB signaling cascade. CREB transactivated PDGFRα expression by direct binding of the promoter of the PDGFRα gene. Depletion of PDGFRα attenuated the tumorigenicity of Pten-null cells in nude mice. Moreover, the PI3K-AKT signaling pathway has been shown to positively correlate with PDGFRα expression in multiple cancers. Augmented PDGFRα was associated with poor survival of cancer patients. Lastly, combination treatment with the AKT inhibitor MK-2206 and the PDGFR inhibitor CP-673451 displayed synergistic anti-tumor effects. Therefore, activation of the AKT1-CREB-PDGFRα signaling pathway contributes to the tumor growth induced by PTEN deficiency and should be targeted for cancer treatment.

Cancers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 886 ◽  
Author(s):  
Alfonso Parrilla ◽  
Marta Barber ◽  
Blanca Majem ◽  
Josep Castellví ◽  
Juan Morote ◽  
...  

Identifying novel actionable factors that critically contribute to tumorigenesis is essential in ovarian cancer, an aggressive and disseminative tumor, with limited therapeutic options available. Here we show that Aurora Borealis (BORA), a mitotic protein that plays a key role in activating the master mitotic kinase polo-like kinase 1 (PLK1), has an oncogenic role in ovarian cancer. Gain and loss of function assays on mouse models and ex vivo patient-derived ascites cultures revealed an oncogenic role of BORA in tumor development and a transcriptome-analysis in clinically representative models depicted BORA’s role in survival, dissemination and inflammatory cancer related-pathways. Importantly, combinatory treatments of FDA-approved inhibitors against oncogenic downstream effectors of BORA displayed synergistic effect in ovarian cancer models, offering promising therapeutic value. Altogether, our findings uncovered for the first time a critical role of BORA in the viability of human cancer cells providing potential novel therapeutic opportunities for ovarian cancer management.


2021 ◽  
Author(s):  
Klaske Marijke Schukken ◽  
Jason Meyer Sheltzer

Aneuploidy is a hallmark of human cancers, but the effects of aneuploidy on protein expression remain poorly understood. To uncover how chromosome copy number changes influence the cancer proteome, we have conducted an analysis of hundreds of human cancer cell lines with matched copy number, RNA expression, and protein expression data. We found that a majority of proteins exhibit dosage compensation and fail to change by the degree expected based on chromosome copy number alone. We uncovered a variety of gene groups that were recurrently buffered upon both chromosome gain and loss, including protein complex subunits and cell cycle genes. Several genetic and biophysical factors were predictive of protein buffering, highlighting complex post-translational regulatory mechanisms that maintain appropriate gene product dosage. Finally, we established that chromosomal aneuploidy has an unexpectedly moderate effect on the expression of oncogenes and tumor suppressors, demonstrating that these key cancer drivers can be subject to dosage compensation as well. In total, our comprehensive analysis of aneuploidy and dosage compensation across cancers will help identify the key driver genes encoded on altered chromosomes and will shed light on the overall consequences of aneuploidy during tumor development.


2020 ◽  
Vol 12 (562) ◽  
pp. eaba4434
Author(s):  
Karin Hansson ◽  
Katarzyna Radke ◽  
Kristina Aaltonen ◽  
Jani Saarela ◽  
Adriana Mañas ◽  
...  

Neuroblastoma is a childhood malignancy with often dismal prognosis; relapse is common despite intense treatment. Here, we used human tumor organoids representing multiple MYCN-amplified high-risk neuroblastomas to perform a high-throughput drug screen with approved or emerging oncology drugs. Tumor-selective effects were calculated using drug sensitivity scores. Several drugs with previously unreported anti-neuroblastoma effects were identified by stringent selection criteria. ARRY-520, an inhibitor of kinesin spindle protein (KSP), was among those causing reduced viability. High expression of the KSP-encoding gene KIF11 was associated with poor outcome in neuroblastoma. Genome-scale loss-of-function screens in hundreds of human cancer cell lines across 22 tumor types revealed that KIF11 is particularly important for neuroblastoma cell viability. KSP inhibition in neuroblastoma patient-derived xenograft (PDX) cells resulted in the formation of abnormal monoastral spindles, mitotic arrest, up-regulation of mitosis-associated genes, and apoptosis. In vivo, KSP inhibition caused regression of MYCN-amplified neuroblastoma PDX tumors. Furthermore, treatment of mice harboring orthotopic neuroblastoma PDX tumors resulted in increased survival. Our results suggested that KSP inhibition could be a promising treatment strategy in children with high-risk neuroblastoma.


2021 ◽  
Author(s):  
Dong Ma ◽  
Zhe Pan ◽  
Quan Chang ◽  
Jin-jin Zhang ◽  
Xiao Liu ◽  
...  

Abstract Background: Epiplakin1 (Eppk1) is part of epidermal growth factor (EGF) signal and takes part in reorganization of cytoskeleton and cell proliferation. However, the role of Eppk1 in cervical cancer (CC) remains unknown.Methods: To express Eppk1 and KLF5 and their correlation, we used RNA-sequence, RT-qPCR, TCGA database and immunofluorescence staining in vitro and in different pathological cervical tissues. In CC cell lines, we tested adenovirus-mediated over expression or knockdown of KLF5 and siRNA-mediated knockdown of Eppk1 and a suiting assessment of cell proliferation and cell signaling by western blot and CCK8 tests. We studied the mechanism by which KLF5 regulates Eppk1 expression by reporter gene test and chromatin immunoprecipitation test.Results: Eppk1 expression promoted in CC tissues and cell lines compared with increased KLF5 expression. The results of immunofluorescence staining further showed the increased co-expression of Eppk1 and KLF5 correlated substantially with tumorigenesis in cervical tissues. Overexpression of KLF5 significantly increased Eppk1 expression at transcription and translation levels. Conversely, the knockdown of KLF5 by siRNA against KLF5 decreased Eppk1 expression. Mechanically, KLF5 activated Eppk1 transcription by direct binding to the Eppk1 promoter. Gain- and loss-of-function experiments reported that KLF5 promoted cell proliferation in Hela partly dependent on Eppk1 upregulation. Besides, KLF5-mediated activation of p38 signaling significantly decreased after Eppk1 knockdown compared with decline of proliferation, suggesting that Eppk1 lies upstream of p38 signaling affecting cell proliferation. Finally, Eppk1 expression is positively correlated with tumor size in clinicopathological features of CC. Conclusions: Eppk1 may be an effective therapeutic target for affecting p38 signaling pathway and cell proliferation in cervical cancer.


2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Mingjie Zheng ◽  
Jun Wang

The cardiac conduction system (CCS) is required for initiating and maintaining regular rhythmic heartbeats. The fundamental Hippo signaling pathway plays critical roles in the heart, yet its role in the CCS remains largely unknown. Here, we found that conditional knockout (CKO) of Hippo signaling kinases Lats1 and Lats2 in the CCS using Hcn4 CreERT2 , led to cardiac arrhythmias in adult mice. Compared with controls, Lats1/2 CKO mutant mice had disrupted calcium homeostasis, increased fibrosis and more fibroblast proliferation in the sinoatrial node. Deletion of the Hippo signaling effectors Yap and Taz in the CCS rescued phenotypes caused by Lats1/2 deletion, and these mice had rescued sinus rhythm and reduced fibrosis, which indicated that Lats1/2 function through Yap and Taz in CCS. Our Cleavage Under Targets and Tagmentation (CUT&Tag)-sequencing using Yap antibody followed by RNA-Seq revealed that Yap directly regulates calcium homeostasis genes such as Ryr2 and fibrosis induction genes such as TGF-β family. Further, we discovered that miR-17-92 represses Hippo signaling by directly suppressing Lats2 expression. miR-17-92 CKO in the CCS led to increased Hippo signaling activity and cardiac arrhythmias, indicating that a fine-tuned level of Hippo signaling is critical for CCS homeostasis. Together, our findings reveal the critical role of a miR-Hippo-Yap genetic pathway in maintaining CCS homeostasis.


2018 ◽  
Author(s):  
Lucile Astorgues-Xerri ◽  
Mathieu Martinet ◽  
Jinan Abdullah ◽  
Sandrine Faivre ◽  
Eric Raymond ◽  
...  

2013 ◽  
Vol 221 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Alzbeta Kamenickova ◽  
Eva Anzenbacherova ◽  
Petr Pavek ◽  
Anatoly A. Soshilov ◽  
Michael S. Denison ◽  
...  

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