scholarly journals A human antibody against human endothelin receptor type A that exhibits antitumor potency

2021 ◽  
Author(s):  
Man-Seok Ju ◽  
Hye-Mi Ahn ◽  
Seong-Gu Han ◽  
Sanghwan Ko ◽  
Jung-Hyun Na ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Xenograft Model ◽  
High Specificity ◽  
Type A ◽  
Receptor Type ◽  
Phage Library ◽  
Human Antibody ◽  
Endothelin Receptor ◽  
Single Chain ◽  
Mouse Xenograft Model

AbstractEndothelin receptor A (ETA), a class A G-protein-coupled receptor (GPCR), is involved in the progression and metastasis of colorectal, breast, lung, ovarian, and prostate cancer. We overexpressed and purified human endothelin receptor type A in Escherichia coli and reconstituted it with lipid and membrane scaffold proteins to prepare an ETA nanodisc as a functional antigen with a structure similar to that of native GPCR. By screening a human naive immune single-chain variable fragment phage library constructed in-house, we successfully isolated a human anti-ETA antibody (AG8) exhibiting high specificity for ETA in the β-arrestin Tango assay and effective inhibitory activity against the ET-1-induced signaling cascade via ETA using either a CHO-K1 cell line stably expressing human ETA or HT-29 colorectal cancer cells, in which AG8 exhibited IC50 values of 56 and 51 nM, respectively. In addition, AG8 treatment repressed the transcription of inhibin βA and reduced the ETA-induced phosphorylation of protein kinase B and extracellular regulated kinase. Furthermore, tumor growth was effectively inhibited by AG8 in a colorectal cancer mouse xenograft model. The human anti-ETA antibody isolated in this study could be used as a potential therapeutic for cancers, including colorectal cancer.

scholarly journals Oncogenic lncRNA ZNF561-AS1 is essential for colorectal cancer proliferation and survival through regulation of miR-26a-3p/miR-128-5p-SRSF6 axis

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zizhen Si ◽  
Lei Yu ◽  
Haoyu Jing ◽  
Lun Wu ◽  
Xidi Wang
Keyword(s):  
Colorectal Cancer ◽  
Rna Binding ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Cancer Proliferation ◽  
Mouse Xenograft ◽  
Mouse Xenograft Model

Abstract Background Long non-coding RNAs (lncRNA) are reported to influence colorectal cancer (CRC) progression. Currently, the functions of the lncRNA ZNF561 antisense RNA 1 (ZNF561-AS1) in CRC are unknown. Methods ZNF561-AS1 and SRSF6 expression in CRC patient samples and CRC cell lines was evaluated through TCGA database analysis, western blot along with real-time PCR. SRSF6 expression in CRC cells was also examined upon ZNF561-AS1 depletion or overexpression. Interaction between miR-26a-3p, miR-128-5p, ZNF561-AS1, and SRSF6 was examined by dual luciferase reporter assay, as well as RNA binding protein immunoprecipitation (RIP) assay. Small interfering RNA (siRNA) mediated knockdown experiments were performed to assess the role of ZNF561-AS1 and SRSF6 in the proliferative actives and apoptosis rate of CRC cells. A mouse xenograft model was employed to assess tumor growth upon ZNF561-AS1 knockdown and SRSF6 rescue. Results We find that ZNF561-AS1 and SRSF6 were upregulated in CRC patient tissues. ZNF561-AS1 expression was reduced in tissues from treated CRC patients but upregulated in CRC tissues from relapsed patients. SRSF6 expression was suppressed and enhanced by ZNF561-AS1 depletion and overexpression, respectively. Mechanistically, ZNF561-AS1 regulated SRSF6 expression by sponging miR-26a-3p and miR-128-5p. ZNF561-AS1-miR-26a-3p/miR-128-5p-SRSF6 axis was required for CRC proliferation and survival. ZNF561-AS1 knockdown suppressed CRC cell proliferation and triggered apoptosis. ZNF561-AS1 depletion suppressed the growth of tumors in a model of a nude mouse xenograft. Similar observations were made upon SRSF6 depletion. SRSF6 overexpression reversed the inhibitory activities of ZNF561-AS1 in vivo, as well as in vitro. Conclusion In summary, we find that ZNF561-AS1 promotes CRC progression via the miR-26a-3p/miR-128-5p-SRSF6 axis. This study reveals new perspectives into the role of ZNF561-AS1 in CRC.

GSK3β Inhibition Synergizes with PARP Inhibitors through the Induction of Homologous Recombination Deficiency in Colorectal Cancer

2020 ◽  
Author(s):  
Ning Zhang ◽  
Yu-Nan Tian ◽  
Li-Na Zhou ◽  
Meng-Zhu Li ◽  
Shan-Shan Song ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Homologous Recombination ◽  
High Throughput Screening ◽  
Glycogen Synthase ◽  
Objective Response ◽  
Xenograft Model ◽  
Parp Inhibitors ◽  
High Rate ◽  
Parp Inhibition ◽  
Mouse Xenograft Model

Abstract Background: Monotherapy with poly ADP-ribose polymerase (PARP) inhibitors results in limited objective response rate (≤ 60% in most cases) in patients with homologous recombination repair (HRR)-deficient cancer, which suggests a high rate of resistance in this subset of patients to PARP inhibitors (PARPi). To overcome resistance to PARPi and to broaden their clinical use, we performed high-throughput screening of 99 anticancer drugs in combination with PARPi to identify potential therapeutic combinations. Methods: The effects of PARPi combined with glycogen synthase kinase 3 (GSK3) inhibitors were investigated in vitro with respect to cell viability, cell cycle and apoptosis. The synergy was assessed by calculation of the combination index (CI). GSK3α null and GSK3β null cells were generated using CRISPR/Cas9 technique. The underlying mechanism was examined by western blotting, flow cytometry, qRT-PCR and fluorescence microscopy. This combination was also evaluated in the mouse xenograft model; tumor growth and tumor lysates were analyzed, and the immunohistochemistry assay was performed. All data are presented as mean ± SD. Comparison between two groups was performed with the Student’s t-test.Result: The data showed that ~25% of oncological drugs and kinase inhibitors that were evaluated displayed synergy with PARPi in HCT-15 cells. Among the tested agents, GSK3 inhibitors (GSK3i) exhibited the strongest synergistic effect with PARPi. Moreover, the synergistic antitumor effect of GSK3 and PARP inhibition was confirmed in a panel of colorectal cancer (CRC) cell lines with diverse genetic backgrounds. Additionally, inhibition or genetic depletion of GSK3β was found to impair HRR of DNA and reduce the mRNA and protein level of BRCA1. Finally, we demonstrated that inhibition or depletion of GSK3β could enhance the in vivo sensitivity to simmiparib without toxicity.Conclusion: Our results provide a mechanistic understanding of combination of PARP and GSK3 inhibition, and support the clinical development of this combination therapy for CRC patients.

scholarly journals Loss‐of‐function of Endothelin receptor type A results in Oro‐Oto‐Cardiac syndrome

2020 ◽  
Vol 182 (5) ◽  
pp. 1104-1116
Author(s):  
Amanda Barone Pritchard ◽  
Stanley M. Kanai ◽  
Bryan Krock ◽  
Erica Schindewolf ◽  
Jennifer Oliver‐Krasinski ◽  
...  
Keyword(s):  
Type A ◽  
Receptor Type ◽  
Endothelin Receptor ◽  
Loss Of Function ◽  
Cardiac Syndrome

scholarly journals MicroRNA-587 antagonizes 5-FU-induced apoptosis and confers drug resistance by regulating PPP2R1B expression in colorectal cancer

2015 ◽  
Vol 6 (8) ◽  
pp. e1845-e1845 ◽  
Author(s):  
Y Zhang ◽  
G Talmon ◽  
J Wang
Keyword(s):  
Colorectal Cancer ◽  
Drug Resistance ◽  
Cancer Treatment ◽  
Xenograft Model ◽  
Akt Inhibitor ◽  
Akt Phosphorylation ◽  
Xiap Expression ◽  
Mouse Xenograft Model ◽  
Response To Chemotherapy ◽  
Induced Apoptosis

Abstract Drug resistance is one of the major hurdles for cancer treatment. However, the underlying mechanisms are still largely unknown and therapeutic options remain limited. In this study, we show that microRNA (miR)-587 confers resistance to 5-fluorouracil (5-FU)-induced apoptosis in vitro and reduces the potency of 5-FU in the inhibition of tumor growth in a mouse xenograft model in vivo. Further studies indicate that miR-587 modulates drug resistance through downregulation of expression of PPP2R1B, a regulatory subunit of the PP2A complex, which negatively regulates AKT activation. Knockdown of PPP2R1B expression increases AKT phosphorylation, which leads to elevated XIAP expression and enhanced 5-FU resistance; whereas rescue of PPP2R1B expression in miR-587-expressing cells decreases AKT phosphorylation/XIAP expression, re-sensitizing colon cancer cells to 5-FU-induced apoptosis. Moreover, a specific and potent AKT inhibitor, MK2206, reverses miR-587-conferred 5-FU resistance. Importantly, studies of colorectal cancer specimens indicate that the expression of miR-587 and PPP2R1B positively and inversely correlates with chemoresistance, respectively, in colorectal cancer. These findings indicate that the miR-587/PPP2R1B/pAKT/XIAP signaling axis has an important role in mediating response to chemotherapy in colorectal cancer. A major implication of our study is that inhibition of miR-587 or restoration of PPP2R1B expression may have significant therapeutic potential to overcome drug resistance in colorectal cancer patients and that the combined use of an AKT inhibitor with 5-FU may increase efficacy in colorectal cancer treatment.

Endothelin receptor type A and B gene expression in human nonpregnant, term pregnant, and preeclamptic uterus

1996 ◽  
Vol 175 (5) ◽  
pp. 1295-1300 ◽  
Author(s):  
Kerstin Wolff ◽  
Margaretha Faxén ◽  
Nils-Olov Lunell ◽  
Henry Nisell ◽  
Bo Lindblom
Keyword(s):  
Gene Expression ◽  
Type A ◽  
Receptor Type ◽  
Endothelin Receptor
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