scholarly journals MicroRNA-132 Plays an Independent Prognostic Role in Pancreatic Ductal Adenocarcinoma and Acts as a Tumor Suppressor

2019 ◽  
Vol 18 ◽  
pp. 153303381882431 ◽  
Author(s):  
Yan Chen ◽  
Huiyun Zhu ◽  
Yuqiong Wang ◽  
Yingxiao Song ◽  
Pingping Zhang ◽  
...  

The role of microRNA-132 in human pancreatic ductal adenocarcinomas is still ambiguous. We explored the association between microRNA-132 and pancreatic ductal adenocarcinoma prognosis. The expression of microRNA-132 in 50 pancreatic ductal adenocarcinoma tissue samples and pancreatic ductal adenocarcinoma cell lines was examined, and the association between its expression and pancreatic ductal adenocarcinoma prognosis was assessed. Functional analysis and factors downstream of microRNA-132 were investigated. Kaplan-Meier survival curves showed that high expression of microRNA-132 was a significant prognostic factor for 1-year survival of patients with pancreatic ductal adenocarcinoma ( P = .028). Multivariate analysis for overall survival indicated that high expression of microRNA-132 was an independent prognostic factor for patients with pancreatic ductal adenocarcinoma ( P = .044). Low expression of microRNA-132 was associated with poor prognosis in pancreatic ductal adenocarcinoma. Ectopic expression of microRNA-132 significantly inhibited proliferation and promoted apoptosis of 2 pancreatic ductal adenocarcinoma cell lines. Bioinformatic analysis revealed that microRNA-132 may exert its effects on pancreatic ductal adenocarcinoma through downregulating mitogen-activated protein kinase 3 and nuclear transcription factor Y subunit α. The results of this study further our understanding of the relationship between microRNA-132 and pancreatic ductal adenocarcinoma by showing that microRNA-132 might inhibit the progression of pancreatic ductal adenocarcinoma by regulating mitogen-activated protein kinase and nuclear transcription factor Y subunit alpha.

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Derek Wong ◽  
Lisa Sogerer ◽  
Samantha S. Lee ◽  
Victor Wong ◽  
Amy Lum ◽  
...  

Abstract Background Aberrations in Capicua (CIC) have recently been implicated as a negative prognostic factor in a multitude of cancer types through the derepression of targets downstream of the mitogen-activated protein kinase (MAPK) signaling cascade, such as oncogenic E26 transformation-specific (ETS) transcription factors. The Ataxin-family protein ATXN1L has previously been reported to interact with CIC in both developmental and disease contexts to facilitate the repression of CIC target genes and promote the post-translational stability of CIC. However, little is known about the mechanisms at the base of ATXN1L-mediated CIC post-translational stability. Results Functional in vitro studies utilizing ATXN1LKO human cell lines revealed that loss of ATXN1L leads to the accumulation of polyubiquitinated CIC protein, promoting its degradation through the proteasome. Although transcriptomic signatures of ATXN1LKO cell lines indicated upregulation of the mitogen-activated protein kinase pathway, ERK activity was found to contribute to CIC function but not stability. Degradation of CIC protein following loss of ATXN1L was instead observed to be mediated by the E3 ubiquitin ligase TRIM25 which was further validated using glioma-derived cell lines and the TCGA breast carcinoma and liver hepatocellular carcinoma cohorts. Conclusions The post-translational regulation of CIC through ATXN1L and TRIM25 independent of ERK activity suggests that the regulation of CIC stability and function is more intricate than previously appreciated and involves several independent pathways. As CIC status has become a prognostic factor in several cancer types, further knowledge into the mechanisms which govern CIC stability and function may prove useful for future therapeutic approaches.


2005 ◽  
Vol 139 (1) ◽  
pp. 127-137 ◽  
Author(s):  
Yun-Kiam Yap ◽  
Yutaka Kodama ◽  
Frank Waller ◽  
Kwi Mi Chung ◽  
Hirokazu Ueda ◽  
...  

1998 ◽  
Vol 18 (4) ◽  
pp. 1946-1955 ◽  
Author(s):  
Jun Xing ◽  
Jon M. Kornhauser ◽  
Zhengui Xia ◽  
Elizabeth A. Thiele ◽  
Michael E. Greenberg

ABSTRACT The mechanisms by which growth factor-induced signals are propagated to the nucleus, leading to the activation of the transcription factor CREB, have been characterized. Nerve growth factor (NGF) was found to activate multiple signaling pathways that mediate the phosphorylation of CREB at the critical regulatory site, serine 133 (Ser-133). NGF activates the extracellular signal-regulated kinase (ERK) mitogen-activated protein kinases (MAPKs), which in turn activate the pp90 ribosomal S6 kinase (RSK) family of Ser/Thr kinases, all three members of which were found to catalyze CREB Ser-133 phosphorylation in vitro and in vivo. In addition to the ERK/RSK pathway, we found that NGF activated the p38 MAPK and its downstream effector, MAPK-activated protein kinase 2 (MAPKAP kinase 2), resulting in phosphorylation of CREB at Ser-133. Inhibition of either the ERK/RSK or the p38/MAPKAP kinase 2 pathway only partially blocked NGF-induced CREB Ser-133 phosphorylation, suggesting that either pathway alone is sufficient for coupling the NGF signal to CREB activation. However, inhibition of both the ERK/RSK and the p38/MAPKAP kinase 2 pathways completely abolished NGF-induced CREB Ser-133 phosphorylation. These findings indicate that NGF activates two distinct MAPK pathways, both of which contribute to the phosphorylation of the transcription factor CREB and the activation of immediate-early genes.


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