scholarly journals HAT1 Promotes Gemcitabine Resistance by Regulating the PVT1/EZH2 Complex in Pancreatic Cancer

Author(s):  
Yan Sun ◽  
Jian Shen ◽  
Dianyun Ren ◽  
Yingke Zhou ◽  
Jingyuan Zhao ◽  
...  

Abstract Background: The poor prognosis of pancreatic cancer is primarily due to the development of resistance to therapies, including gemcitabine. PVT1 has been shown to interact with EZH2, promoting gemcitabine resistance in pancreatic cancer. Methods: In this study, we assessed the ability of PVT1/EZH2 targeting to reverse resistance to gemcitabine in pancreatic cancer cells. MTS assay, colony formation assay, and mouse xenotransplantation experiments were used to evaluate the anti-tumor effects of gemcitabine in HAT1 knockdown or overexpressing pancreatic cancer cells. The relationship between HAT1 and PVT1 in pancreatic cancer was determined by RNA sequencing, quantitative real-time PCR, and chromatin immunoprecipitation. Co-immunoprecipitation, pull-downs, western blotting, and immunohistochemistry were used to assess the relationship between HAT1 and EZH2 in pancreatic cancer. Chitosan (CS)-tripolyphosphate (TPP)-siHAT1 nanoparticles were developed to evaluate their effects on the anti-tumor potential of gemcitabine in pancreatic cancer. Student’s t-test, one-way analysis of variance (ANOVA), or two-way ANOVA was used to evaluate statistical significance. P-values <0.05 were considered statistically significant. All values were expressed as means ± SD. Results: Our results showed that the aberrant HAT1 expression promoted gemcitabine resistance in pancreatic cancer cells. We also found that HAT1 enhanced the binding of BRD4 to the PVT1 promoter, thereby promoting PVT1 transcription. Moreover, we found that HAT1 prevented EZH2 degradation by interfering with UBR4 binding to the N-terminal domain of EZH2, thus maintaining EZH2 protein stability. Finally, we showed that CS-TPP-siHAT1 nanoparticles augmented the anti-tumor effects of gemcitabine in pancreatic cancer cells in vitro and in vivo. Conclusions: Our findings suggest that by increasing the levels of the PVT1/EZH2 complex, HAT1 promotes gemcitabine resistance in pancreatic cancer. Therefore, HAT1 is a promising therapeutic target for pancreatic cancer.

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Guangbing Xiong ◽  
Chang Liu ◽  
Gang Yang ◽  
Mengyu Feng ◽  
Jianwei Xu ◽  
...  

Abstract Background Chemoresistance is one of the main causes of poor prognosis in pancreatic cancer patients. Understanding the mechanisms implicated in chemoresistance of pancreatic cancer is critical to improving patient outcomes. Recent evidences indicate that the long noncoding RNAs (lncRNAs) are involving in chemoresistance of pancreatic cancer. However, the mechanisms of lncRNAs contribute to resistance in pancreatic cancer and remain largely unknown. The objective of this study is to construct a chemoresistance-related lncRNA-associated competing endogenous RNA (ceRNA) network of pancreatic cancer and identify the key lncRNAs in regulating chemoresistance of the network. Methods Firstly, lncRNA expression profiling of gemcitabine-resistant pancreatic cancer cells was performed to identify lncRNAs related to chemoresistance by microarray analysis. Secondly, with insights into the mechanism of ceRNA, we used a bioinformatics approach to construct a chemoresistance-related lncRNAs-associated ceRNA network. We then identified the topological key lncRNAs in the ceRNA network and demonstrated its function or mechanism in chemoresistance of pancreatic cancer using molecular biological methods. Further studies evaluated its expression to assess its potential association with survival in patients with pancreatic cancer. Results Firstly, we demonstrated that lncRNAs were dysregulated in gemcitabine-resistant pancreatic cancer cells. We then constructed a chemoresistance-related lncRNA-associated ceRNA network and proposed that lncRNA Homo sapiens glutathione S-transferase mu 3, transcript variant 2 and noncoding RNA (GSTM3TV2; NCBI Reference Sequence: NR_024537.1) might act as a key ceRNA to enhance chemoresistance by upregulating L-type amino acid transporter 2 (LAT2) and oxidized low-density lipoprotein receptor 1(OLR1) in pancreatic cancer. Further studies demonstrated that GSTM3TV2, overexpressed in gemcitabine-resistant cells, enhanced the gemcitabine resistance of pancreatic cancer cells in vitro and in vivo. Mechanistically, we identified that GSTM3TV2 upregulated LAT2 and OLR1 by competitively sponging let-7 to promote gemcitabine resistance. In addition, we revealed that the expression levels of GSTM3TV2 were significantly increased in pancreatic cancer tissues and were associated with poor prognosis. Conclusion Our results suggest that GSTM3TV2 is a crucial oncogenic regulator involved in chemoresistance and could be a new therapeutic target or prognostic marker in pancreatic cancer.


2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Yan Sun ◽  
Dianyun Ren ◽  
Yingke Zhou ◽  
Jian Shen ◽  
Heshui Wu ◽  
...  

AbstractThe poor prognosis of pancreatic cancer is primarily due to the development of resistance to therapies, including gemcitabine. The long noncoding RNA PVT1 (lncRNA PVT1) has been shown to interact with enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2), promoting gemcitabine resistance in pancreatic cancer. In this study, we found histone acetyltransferase 1 (HAT1) enhanced the tolerance of pancreatic cancer cells to gemcitabine and HAT1-mediated resistance mechanisms were regulated by PVT1 and EZH2. Our results showed that the aberrant HAT1 expression promoted gemcitabine resistance, while silencing HAT1 restored gemcitabine sensitivity. Moreover, HAT1 depletion caused a notable increase of gemcitabine sensitivity in gemcitabine-resistant pancreatic cancer cell lines. Further research found that HAT1 increased PVT1 expression to induce gemcitabine resistance, which enhanced the binding of bromodomain containing 4 (BRD4) to the PVT1 promoter, thereby promoting PVT1 transcription. Besides, HAT1 prevented EZH2 degradation by interfering with ubiquitin protein ligase E3 component n-recognin 4 (UBR4) binding to the N-terminal domain of EZH2, thus maintaining EZH2 protein stability to elevate the level of EZH2 protein, which also promoted HAT1-mediated gemcitabine resistance. These results suggested that HAT1 induced gemcitabine resistance of pancreatic cancer cells through regulating PVT1/EZH2 complex. Given this, Chitosan (CS)-tripolyphosphate (TPP)-siHAT1 nanoparticles were developed to block HAT1 expression and improve the antitumor effect of gemcitabine. The results showed that CS-TPP-siHAT1 nanoparticles augmented the antitumor effects of gemcitabine in vitro and in vivo. In conclusion, HAT1-targeted therapy can improve observably gemcitabine sensitivity of pancreatic cancer cells. HAT1 is a promising therapeutic target for pancreatic cancer.


2010 ◽  
Vol 999 (999) ◽  
pp. 1-11
Author(s):  
P. Ulivi ◽  
C. Arienti ◽  
W. Zoli ◽  
M. Scarsella ◽  
S. Carloni ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2017
Author(s):  
Lital Sharvit ◽  
Rinat Bar-Shalom ◽  
Naiel Azzam ◽  
Yaniv Yechiel ◽  
Solomon Wasser ◽  
...  

Pancreatic cancer is a highly lethal disease with limited options for effective therapy and the lowest survival rate of all cancer forms. Therefore, a new, effective strategy for cancer treatment is in need. Previously, we found that a culture liquid extract of Cyathus striatus (CS) has a potent antitumor activity. In the present study, we aimed to investigate the effects of Cyathus striatus extract (CSE) on the growth of pancreatic cancer cells, both in vitro and in vivo. The proliferation assay (XTT), cell cycle analysis, Annexin/PI staining and TUNEL assay confirmed the inhibition of cell growth and induction of apoptosis by CSE. A Western blot analysis demonstrated the involvement of both the extrinsic and intrinsic apoptosis pathways. In addition, a RNAseq analysis revealed the involvement of the MAPK and P53 signaling pathways and pointed toward endoplasmic reticulum stress induced apoptosis. The anticancer activity of the CSE was also demonstrated in mice harboring pancreatic cancer cell line-derived tumor xenografts when CSE was given for 5 weeks by weekly IV injections. Our findings suggest that CSE could potentially be useful as a new strategy for treating pancreatic cancer.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Feng Guo ◽  
Yingke Zhou ◽  
Hui Guo ◽  
Dianyun Ren ◽  
Xin Jin ◽  
...  

AbstractNR5A2 is a transcription factor regulating the expression of various oncogenes. However, the role of NR5A2 and the specific regulatory mechanism of NR5A2 in pancreatic ductal adenocarcinoma (PDAC) are not thoroughly studied. In our study, Western blotting, real-time PCR, and immunohistochemistry were conducted to assess the expression levels of different molecules. Wound-healing, MTS, colony formation, and transwell assays were employed to evaluate the malignant potential of pancreatic cancer cells. We demonstrated that NR5A2 acted as a negative prognostic biomarker in PDAC. NR5A2 silencing inhibited the proliferation and migration abilities of pancreatic cancer cells in vitro and in vivo. While NR5A2 overexpression markedly promoted both events in vitro. We further identified that NR5A2 was transcriptionally upregulated by BRD4 in pancreatic cancer cells and this was confirmed by Chromatin immunoprecipitation (ChIP) and ChIP-qPCR. Besides, transcriptome RNA sequencing (RNA-Seq) was performed to explore the cancer-promoting effects of NR5A2, we found that GDF15 is a component of multiple down-regulated tumor-promoting gene sets after NR5A2 was silenced. Next, we showed that NR5A2 enhanced the malignancy of pancreatic cancer cells by inducing the transcription of GDF15. Collectively, our findings suggest that NR5A2 expression is induced by BRD4. In turn, NR5A2 activates the transcription of GDF15, promoting pancreatic cancer progression. Therefore, NR5A2 and GDF15 could be promising therapeutic targets in pancreatic cancer.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kim Rouven Liedtke ◽  
Sander Bekeschus ◽  
André Kaeding ◽  
Christine Hackbarth ◽  
Jens-Peter Kuehn ◽  
...  

2000 ◽  
Vol 118 (4) ◽  
pp. A540
Author(s):  
Thomas Seufferlein ◽  
Michael J. Seckl ◽  
Michael Beil ◽  
Hardi Luhrs ◽  
Roland M. Schmid ◽  
...  

2021 ◽  
Vol 11 ◽  
Author(s):  
Congjun Zhang ◽  
Shuangyan Ou ◽  
Yuan Zhou ◽  
Pei Liu ◽  
Peiying Zhang ◽  
...  

ObjectivePancreatic cancer is one of the most lethal human malignancies. Gemcitabine is widely used to treat pancreatic cancer, and the resistance to chemotherapy is the major difficulty in treating the disease. N6-methyladenosine (m6A) modification, which regulates RNA splicing, stability, translocation, and translation, plays critical roles in cancer physiological and pathological processes. METTL14, an m6A Lmethyltransferase, was found deregulated in multiple cancer types. However, its role in gemcitabine resistance in pancreatic cancer remains elusive.MethodsThe mRNA and protein level of m6A modification associated genes were assessed by QRT-PCR and western blotting. Then, gemcitabine‐resistant pancreatic cancer cells were established. The growth of pancreatic cancer cells were analyzed using CCK8 assay and colony formation assay. METTL14 was depleted by using shRNA. The binding of p65 on METTL14 promoter was assessed by chromatin immunoprecipitation (ChIP) assay. Protein level of deoxycytidine kinase (DCK) and cytidine deaminase (CDA) was evaluated by western blotting. In vivo experiments were conducted to further confirm the critical role of METTL14 in gemcitabine resistance.ResultsWe found that gemcitabine treatment significantly increased the expression of m6A methyltransferase METTL14, and METTL14 was up-regulated in gemcitabine-resistance human pancreatic cancer cells. Suppression of METTL14 obviously increased the sensitivity of gemcitabine in resistant cells. Moreover, we identified that transcriptional factor p65 targeted the promoter region of METTL14 and up-regulated its expression, which then increased the expression of cytidine deaminase (CDA), an enzyme inactivates gemcitabine. Furthermore, in vivo experiment showed that depletion of METTL14 rescue the response of resistance cell to gemcitabine in a xenograft model.ConclusionOur study suggested that METTL14 is a potential target for chemotherapy resistance in pancreatic cancer.


2021 ◽  
Vol 8 ◽  
Author(s):  
Fei Xu ◽  
Heshui Wu ◽  
Jiongxin Xiong ◽  
Tao Peng

Gemcitabine (GEM) resistance remains a challenging clinical issue to overcome in chemotherapy against pancreatic cancer. We previously demonstrated that miR-210 derived from pancreatic cancer stem cells enhanced the GEM-resistant properties of pancreatic cancer cells, thus identifying miR-210 as an oncogenic miRNA. Herein, we report the existence of an upstream effector that acts as a competing endogenous RNA (ceRNA) to miR-210. Bioinformatic screening was performed to identify lncRNAs with a binding relationship to miR-210. Overexpression and interference vectors were constructed to demonstrate the effect of ceRNA activity in pancreatic cell behavior, both in vitro and in vivo. DLEU2L (deleted in lymphocytic leukemia 2-like), which is expressed at low levels in pancreatic cancer tissues, was shown to exhibit a binding relationship with miR-210-3p. Overexpression of DLEU2L and silencing of miR-210-3p suppressed the proliferation, migration, and invasion of pancreatic cancer cells while promoting apoptosis. These effects occurred via the inhibition of the Warburg effect (aerobic glycolysis) and AKT/mTOR signaling. In addition, we showed that BRCA2 is a target gene of miR-210-3p, and the downregulation of miR-210-3p by DLEU2L effectively induced an upregulation of BRCA2 via the ceRNA mechanism. In vivo, DLEU2L overexpression and miR-210-3p interference suppressed pancreatic tumor progression, consistent with the results of in vitro studies. The findings of our study establish DLEU2L as a ceRNA to miR-210-3p and reveal the critical role of the DLEU2L/miR-210-3p crosstalk in targeting GEM resistance.


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