scholarly journals Enhancing cytotoxic chemotherapy response through targeted BET bromodomain inhibition in preclinical pancreatic cancer models

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Sandeep Singh ◽  
Ross McCauley ◽  
Johann R. Schwarz ◽  
Roderich Schwarz ◽  
Niranjan Awasthi

Background and Hypothesis:   Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and the standard of care regimen, nab-paclitaxel (NPT) plus gemcitabine (Gem), leads to a dismal 8.5 months median survival. Targeted inhibition of Bromodomain and Extra-Terminal (BET) protein is currently under investigation for several cancers. We hypothesize that BET protein pathway inhibition by iBet-762 will enhance cytotoxic chemotherapy response in PDAC.  Experimental Design:  In vitro cell proliferation assays were performed using WST-1 reagent. Protein expressions were determined by Western Blot analysis. In vivo animal survival and tumor growth experiments were performed in NOD-SCID mice.   Results:  Inhibition in cell proliferation in human PDAC cells at 1 µM concentration in NPT+Gem, iBET-762, and NPT+Gem+iBet762 was 64%, 27%, 76% in AsPC-1; 43%, 13%, 69% in Panc-1; and 42%, 51%, 75% in MIA PaCa cells. iBET-762 decreased oncogenic proteins c-Myc, [Symbol]-catenin, Vimentin, and P-AKT while apoptosis related proteins such as cleaved PARP-1 and cleaved caspase-3 and cell cycle inhibitors proteins P21 & P27 were increased. In a peritoneal dissemination model, median animal survival compared to control (21 days) was increased after therapy with NPT+Gem (33 days, a 57% increase), iBet-762 (30 days, a 43% increase) and NPT+Gem+iBET-762 (44 days, a 110% increase). Effect of iBET-762 in combination with chemotherapy on local tumor growth is currently underway.    Conclusion and Potential Impact:   These findings suggest that the effects of standard chemotherapy can be enhanced through specific inhibition of BET proteins activity, and supports the clinical application of iBET-762 in combination with standard chemotherapy in PDAC patients.

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Eda Shi

Background and Hypothesis: Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal malignancies in Western countries. Nab-paclitaxel (NPT) plus gemcitabine (Gem) is the standard of care for PDAC leading to a dismal 8.5 months median survival. Aberrant signaling of c-MET, Axl and DDR have been reported in a variety of human cancers including PDAC. Merestinib (Mer) is a potent, smallmolecule inhibitor of these pathways. We evaluated the therapeutic efficacy of merestinib to enhance the antitumor response of standard chemotherapy in preclinical models of PDAC. Project Methods: Cell proliferation of PDAC-associated cells (AsPC-1, PANC-1 and fibroblasts) were evaluated by colorimetric WST-1 assay. Protein expression was determined by Western blot analysis. Tumor progression studies were performed in NOD/SCID mice. Results: In vitro studies demonstrated that both nab-paclitaxel plus gemcitabine and merestinib suppressed cell proliferation of PDAC epithelial cells and stromal cells. Importantly, the combination treatment demonstrated additive inhibitory effects. In AsPC-1 cells, at the medium dose level, NPT+Gem, Mer and NPT+Gem+Mer treatments inhibited cell proliferation by 53.9%, 13.5%, and 81.61%, respectively. In PANC-1 cells, at the highest dose level, inhibition in cell proliferation by NPT+Gem, Mer and NPT+Gem+Mer treatments was 53.6%, 3.7%, and 72.8%. In the PDAC-associated fibroblasts, at the medium dose level, NPT+Gem, Mer and NPT+Gem+Mer treatments inhibited growth by 55.3%, 58.0%, and 91.6%. Immunoblot analysis revealed that merestinib caused a decrease in the PI-3K-AKT signaling proteins and an increase in apoptosisrelated proteins cleaved PARP-1 or cleaved caspase-3 in PDAC cells either alone or in combination with nab-paclitaxel and gemcitabine. In vivo study to evaluate tumor growth inhibition effects of merestinib in a subcutaneous PDAC xenograft is currently ongoing. Conclusion: The antitumor effect of standard chemotherapy regimen can be significantly enhanced by the cMET/Axl/DDR pathway inhibitor merestinib, which may lead to clinically relevant therapeutic strategy to increased survival in PDAC patients.


2011 ◽  
Vol 29 (4_suppl) ◽  
pp. 294-294
Author(s):  
N. Awasthi ◽  
M. A. Schwarz ◽  
P. L. Yen ◽  
R. Schwarz

294 Background: Gemcitabine (Gem), the most active drug for locally advanced, non-operable and metastatic PDAC, has limited benefits as single agent or in combination. Endothelial monocyte activating polypeptide II (EMAP, E) enhances Gem effects in PDAC. We evaluated the antitumor activities of EMAP in combination with doxorubicin (Dox) or docetaxel (DT) in PDAC. Methods: In vitro cell proliferation, protein expression and apoptosis were analyzed by WST-1 assay, Western blotting and FACS analysis. In vivo local tumor growth and animal survival experiments were performed in murine xenografts. Results: In vitro PDAC cell proliferation was not affected by EMAP, compared to a small inhibition by Dox, DT and Gem. EMAP combination to these agents did not increase the antiproliferative effects. In endothelial cells (ECs), EMAP, Dox, DT and Gem all inhibited proliferation (59, 79, 96 and 85% at 10 μM, respectively); addition of EMAP caused additive antiproliferative effects. In PDAC cells, no agent caused measurable apoptosis, but in ECs all agents either alone or in combination increased the apoptosis. In vivo, Dox, DT, Gem and EMAP all decreased local tumor growth, and addition of EMAP enhanced inhibitory effects of DT and Gem, but not of Dox (92, 63, 60, 42, 73, 85 and 68 % inhibition after Dox, DT, Gem, E, Dox+E, DT+E and Gem+E, respectively); DT followed by Gem led to 72% inhibition without EMAP, and to 99% with EMAP (p=0.001). Inhibition of intra-tumoral proliferative activity and increase of apoptotic index were enhanced in all EMAP combination groups. Compared to controls (median survival: 21 days), EMAP (20 d) had no, but Dox (31 d) and DT (35 d) had extended survival benefit. EMAP enhanced the DT effect (44 d, p=0.009) but not that of Dox (31 d, p=0.04). In a sequential therapy experiment, median survival after controls, Gem, DT, Gem followed by DT, DT followed by Gem, Gem+E, DT+E, Gem/DT+E and DT/Gem+E was 17, 25, 29, 39, 39, 28, 35, 34 and 41 days, respectively. Conclusions: The antiendothelial agent EMAP enhances antitumor effects of not just gemcitabine. Therefore, combination approaches with EMAP-like agents could render other drugs such as taxanes or their doublets sufficiently effective for clinical applications in PDAC therapy. No significant financial relationships to disclose.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  

Abstract Background T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease with a high risk of induction failure and poor outcomes, with relapse due to drug resistance. Recent studies show that bromodomains and extra-terminal (BET) protein inhibitors are promising anti-cancer agents. ARV-825, comprising a BET inhibitor conjugated with cereblon ligand, was recently developed to attenuate the growth of multiple tumors in vitro and in vivo. However, the functional and molecular mechanisms of ARV-825 in T-ALL remain unclear. This study aimed to investigate the therapeutic efficacy and potential mechanism of ARV-825 in T-ALL. Methods Expression of the BRD4 were determined in pediatric T-ALL samples and differential gene expression after ARV-825 treatment was explored by RNA-seq and quantitative reverse transcription-polymerase chain reaction. T-ALL cell viability was measured by CCK8 assay after ARV-825 administration. Cell cycle was analyzed by propidium iodide (PI) staining and apoptosis was assessed by Annexin V/PI staining. BRD4, BRD3 and BRD2 proteins were detected by western blot in cells treated with ARV-825. The effect of ARV-825 on T-ALL cells was analyzed in vivo. The functional and molecular pathways involved in ARV-825 treatment of T-ALL were verified by western blot and chromatin immunoprecipitation (ChIP). Results BRD4 expression was higher in pediatric T-ALL samples compared with T-cells from healthy donors. High BRD4 expression indicated a poor outcome. ARV-825 suppressed cell proliferation in vitro by arresting the cell cycle and inducing apoptosis, with elevated poly-ADP ribose polymerase and cleaved caspase 3. BRD4, BRD3, and BRD2 were degraded in line with reduced cereblon expression in T-ALL cells. ARV-825 had a lower IC50 in T-ALL cells compared with JQ1, dBET1 and OTX015. ARV-825 perturbed the H3K27Ac-Myc pathway and reduced c-Myc protein levels in T-ALL cells according to RNA-seq and ChIP. In the T-ALL xenograft model, ARV-825 significantly reduced tumor growth and led to the dysregulation of Ki67 and cleaved caspase 3. Moreover, ARV-825 inhibited cell proliferation by depleting BET and c-Myc proteins in vitro and in vivo. Conclusions BRD4 indicates a poor prognosis in T-ALL. The BRD4 degrader ARV-825 can effectively suppress the proliferation and promote apoptosis of T-ALL cells via BET protein depletion and c-Myc inhibition, thus providing a new strategy for the treatment of T-ALL.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yarong Guo ◽  
Bao Chai ◽  
Junmei Jia ◽  
Mudan Yang ◽  
Yanjun Li ◽  
...  

Abstract Objective Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells. Methods CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin. Results Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients’ differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients. Conclusion We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.


2010 ◽  
Vol 19 (11) ◽  
pp. 958-964 ◽  
Author(s):  
Zhiqi Song ◽  
Chun-Di He ◽  
Changkai Sun ◽  
Yanni Xu ◽  
Xin Jin ◽  
...  

2021 ◽  
Vol 11 ◽  
Author(s):  
Yuqiong Wang ◽  
Dan Wang ◽  
Yanmiao Dai ◽  
Xiangyu Kong ◽  
Xian Zhu ◽  
...  

It has been shown that aberrant activation of the Hedgehog (Hh) and nuclear factor-kappa B (NF-κB) signaling pathways plays an important role in the pancreatic carcinogenesis, and KRAS mutation is a hallmark of pancreatic ductal adenocarcinoma (PDAC). Until now, the role of KRAS mutation in the context of crosstalk between Hh and NF-κB signaling pathways in PDAC has not been investigated. This study was to determine whether the crosstalk between the Hh and NF-κB pathways is dependent on KRAS mutation in PDAC. The correlation between Gli1, Shh, NF-κB p65 expression and KRAS mutation in PDAC tissues was firstly examined by immunohistochemistry. Next, Western blotting, qPCR, and immunofluorescence were conducted to examine the biological effects of interleukin-1β (IL-1β) and tumor necrosis factor-alpha (TNF-α) as NF-κB signaling agonists, Shh as an Hh ligand alone or in combination with KRAS small interfering RNA (si-KRAS) in KRAS-mutant PDAC cells (MT-KRAS; SW1990 and Panc-1), wild-type KRAS PDAC cells (WT-KRAS; BxPC-3) and mutant KRAS knock-in BxPC-3 cells in vitro as well as tumor growth in vivo. KRAS mutation-dependent crosstalk between Hh and NF-κB in PDAC cells was further assessed by Ras activity and luciferase reporter assays. The aberrant Hh and NF-κB pathway activation was found in PDAC tissues with KRAS mutation. The same findings were confirmed in MT-KRAS PDAC cells and MT-KRAS knock-in BxPC-3 cells, whereas this activation was not observed in WT-KRAS PDAC cells. However, the activation was significantly down-regulated by KRAS silencing in MT-KRAS PDAC cells. Furthermore, MT-KRAS cancer cell proliferation and survival in vitro and tumor growth after inoculation with MT-KRAS cells in vivo were promoted by NF-κB and Hh signaling activation. The pivotal factor for co-activation of NF-κB and Hh signaling is MT-KRAS protein upregulation, showing that positive crosstalk between Hh and NF-κB pathways is dependent upon KRAS mutation in PDAC.


2020 ◽  
Author(s):  
Qian Chen ◽  
Xiao-Wei Zhou ◽  
Ai-Jun Zhang ◽  
Kang He

Abstract Background: Alpha actinins (ACTNs) are major cytoskeletal proteins and exhibit many non-muscle functions. Emerging evidence have uncovered the regulatory role of ACTNs in tumorigenesis, however, the expression pattern, biological functions, and underlying mechanism of ACTN1 in hepatocellular carcinoma (HCC) remain largely unexplored.Methods: Immunohistochemical analysis of a HCC tissue microarray (n = 157) was performed to determine the expression pattern and prognostic value of ACTN1 in HCC. In vitro loss-of-function study in HCC cells were carried out to investigate ACTN1 knockdown on cell proliferation. In vivo subcutaneous xenograft model and intrahepatic transplantation model were generated to decipher the contribution of ACTN1 in the tumor growth of HCC. Gene set enrichment analysis, quantitative real-time PCR, Co-immunoprecipitation, immunofluorescence and western blotting were performed to identify the underlying molecular mechanism.Results: It was found that ACTN1 was significantly upregulated in HCC tissues and closely related to llpha-fetoprotein level, tumor thrombus, tumor size, TNM stage and patient prognoses. Knockdown of ACTN1 suppressed in vitro cell proliferation and in vivo tumor growth of HCC cells. Mechanistically, knockdown of ACTN1 increased Hippo signaling pathway activity and decrease Rho GTPases activities. Mechanistically, ACTN1 could competitively interact with MOB1 and decrease the phosphorylation of LATS1 and YAP. The growth-promoting effect induced by ACTN1 was significantly abrogated by pharmacological inhibition of YAP with verteporfin or super-TDU.Conclusions: ACTN1 is highly expressed in HCC tissues and acts as a tumor promoter by suppressing Hippo signaling via physical interaction with MOB1. ACTN1 may serve as a potential prognostic marker and therapeutic target for HCC.


2020 ◽  
Author(s):  
Juanjuan Shi ◽  
Xijian Xu ◽  
Dan Zhang ◽  
Jiuyan Zhang ◽  
Hui Yang ◽  
...  

Abstract Background: Long non-coding RNA PTPRG antisense RNA 1 (PTPRG-AS1) deregulation has been reported in various human malignancies and identified as an important modulator of cancer development. Few reports have focused on the detailed role of PTPRG-AS1 in epithelial ovarian cancer (EOC) and its underlying mechanism. This study aimed to determine the physiological function of PTPRG-AS1 in EOC. A series of experiments were also performed to identify the mechanisms through which PTPRG-AS1 exerts its function in EOC.Methods: Reverse transcription-quantitative polymerase chain reaction was used to determine PTPRG-AS1 expression in EOC tissues and cell lines. PTPRG-AS1 was silenced in EOC cells and studied with respect to cell proliferation, apoptosis, migration, and invasion in vitro and tumor growth in vivo. The putative miRNAs that target PTPRG-AS1 were predicted using bioinformatics analysis and further confirmed in luciferase reporter and RNA immunoprecipitation assays.Results: Our data verified the upregulation of PTPRG-AS1 in EOC tissues and cell lines. High PTPRG-AS1 expression was associated with shorter overall survival in patients with EOC. Functionally, EOC cell proliferation, migration, invasion in vitro, and tumor growth in vivo were suppressed by PTPRG-AS1 silencing. In contrast, cell apoptosis was promoted by loss of PTPRG-AS1. Regarding the mechanism, PTPRG-AS1 could serve as a competing endogenous RNA in EOC cells by decoying microRNA-545-3p (miR-545-3p), thereby elevating histone deacetylase 4 (HDAC4) expression. Furthermore, rescue experiments revealed that PTPRG-AS1 knockdown-mediated effects on EOC cells were, in part, counteracted by the inhibition of miR-545-3p or restoration of HDAC4.Conclusions: PTPRG-AS1 functioned as an oncogenic lncRNA that aggravated the malignancy of EOC through the miR-545-3p/HDAC4 ceRNA network. Thus, targeting the PTPRG-AS1/miR-545-3p/HDAC4 pathway may be a novel strategy for EOC anticancer therapy.


2021 ◽  
Vol 30 ◽  
pp. 096368972110255
Author(s):  
Qing Wang ◽  
Kai Li ◽  
Xiaoliang Li

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Increasing evidence suggests that long non-coding RNAs (lncRNAs) function in the tumorigenesis of NSCLC. LINC00958, a newly identified lncRNA, has been reported to be closely linked to tumorigenesis in several cancers. However, its specific role in NSCLC remains unclear. In this study, we determined the expression of LINC00958 in NSCLC by RT-qPCR analysis and evaluated cell proliferation and migration by CCK-8 and transwell assays, respectively. We established a xenograft tumor model to examine the effect of LINC00958 on tumor growth in vivo. Luciferase reporter assays were performed to determine the interaction between LINC00958 and miR-204-3p and the interaction between miR-204-3p and KIF2A. We found that LINC00958 was up-regulated in NSCLC tissues and cell lines. Down-regulation of LINC00958 inhibited cell proliferation and migration in vitro and suppressed tumor growth in vivo. Besides, miR-204-3p was identified as a target of LINC00958 and miR-204-3p inhibitor could reverse the inhibitory effect of LINC00958 knockdown on proliferation and migration of NSCLC cells. We also validated that KIF2A, a direct target of miR-204-3p, was responsible for the biological role of LINC00958. KIF2A antagonized the effect of miR-204-3p on NSCLC cell proliferation and migration and was regulated by LINC00958/miR-204-3p. Taken together, these data indicate that the LINC00958/miR-204-3p/KIF2A axis is critical for NSCLC progression, which might provide a potential therapeutic target of NSCLC.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jing Chen ◽  
Cui-Cui Zhao ◽  
Fei-Ran Chen ◽  
Guo-Wei Feng ◽  
Fei Luo ◽  
...  

Background. Pancreatic cancer is a malignant tumor of the digestive tract, which is difficult to diagnose and treat due to bad early diagnosis. We aimed to explore the role of kinesin superfamily 4A (KIF4A) in pancreatic ductal adenocarcinoma (PDAC). Methods. We first used the bioinformatic website to screen the data of pancreatic cancer in TCGA, and KIF4A protein was detected among the 86 specimens of patients in our hospital combined with clinic-pathological characteristics and survival analysis. KIF4A loss-expression cell lines were established by RNA interference (RNAi). In addition, we performed in vitro cell assays to detect the changes in cell proliferation, migration, and invasion. The proteins involved in the proliferation and metastasis of cancer cells were also detected by western blot. The above results could be proved in vivo. Further, the correlation between KIF4A and CDC5L was analyzed by TCGA and IHC data. Results. We first found a high expression of KIF4A in pancreatic cancer, suggesting a role of KIF4A in the development of pancreatic cancer. KIF4A was found to be differentially expressed ( P < 0.05 ) among the 86 specimens of patients in our hospital and was significantly associated with PDAC TNM stages and tumor size. High KIF4A expression also significantly worsened overall survival (OS) and disease-free survival rate (DFS) ( P < 0.05 , respectively). In addition, cell proliferation, migration, and invasion were inhibited by the KIF4A-shRNA group compared with the control ( P < 0.05 , respectively). In the end, knockdown of KIF4A could inhibit tumor development and metastasis in vivo. Further, the positive correlation between KIF4A and CDC5L existed, and KIF4A might promote pancreatic cancer proliferation by affecting CDC5L expression. Conclusion. In conclusion, the high expression level of KIF4A in PDAC was closely related to poor clinical and pathological status, lymphatic metastasis, and vascular invasion. KIF4A might be involved in promoting the development of PDAC in vitro and in vivo, which might be a new therapeutic target of PDAC.


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