scholarly journals Tanshinone IIA Inhibits Osteosarcoma Growth through a Src Kinase-Dependent Mechanism

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Chao Hu ◽  
Xiaobin Zhu ◽  
Taogen Zhang ◽  
Zhouming Deng ◽  
Yuanlong Xie ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathways ◽  
Cell Lines ◽  
Src Kinase ◽  
Akt Signaling ◽  
Cellular Level ◽  
Tanshinone Iia

Introduction. Osteosarcoma is a malignant tumor associated with high mortality rates due to the toxic side effects of current therapeutic methods. Tanshinone IIA can inhibit cell proliferation and promote apoptosis in vitro, but the exact mechanism is still unknown. The aims of this study are to explore the antiosteosarcoma effect of tanshinone IIA via Src kinase and demonstrate the mechanism of this effect. Materials and Methods. Osteosarcoma MG-63 and U2-OS cell lines were stable transfections with Src-shRNA. Then, the antiosteosarcoma effect of tanshinone IIA was tested in vitro. The protein expression levels of Src, p-Src, p-ERK1/2, and p-AKt were detected by Western blot and RT-PCR. CCK-8 assay and BrdU immunofluorescence assay were used to detect cell proliferation. Transwell assay, cell scratch assay, and flow cytometry were used to detect cell invasion, migration, and cell cycle. Tumor-bearing nude mice with osteosarcoma were constructed. The effect of tanshinone IIA was detected by tumor HE staining, tumor inhibition rate, incidence of lung metastasis, and X-ray. Results. The oncogene role of Src kinase in osteosarcoma is reflected in promoting cell proliferation, invasion, and migration and in inhibiting apoptosis. However, Src has different effects on cell proliferation, apoptosis, and cell cycle regulation among cell lines. At a cellular level, the antiosteosarcoma effect of tanshinone IIA is mediated by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways. At the animal level, tanshinone IIA played a role in resisting osteosarcoma formation by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways. Conclusion. Tanshinone IIA plays an antiosteosarcoma role in vitro and in vivo and inhibits the progression of osteosarcoma mediated by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways.

scholarly journals Cordycepin Reverses Cisplatin Resistance in Non-Small Cell Lung Cancer by Activating AMPK and Inhibiting the AKT Signaling Pathway

2020 ◽  
Author(s):  
Xiao-Zhong Liao ◽  
Ying Gao ◽  
Hong-Wei Zhao ◽  
Mi Zhou ◽  
Dan-Lei Chen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Signaling Pathways ◽  
Cell Lines ◽  
A549 Cells ◽  
Akt Signaling ◽  
Antineoplastic Effect ◽  
Proliferation And Apoptosis ◽  
Underlying Mechanisms

Abstract Background: Cisplatin (DDP) is the firs-line chemotherapeutic agent for the treatment of NSCLC. However, DDP resistance limits their usage to maximize the antineoplastic effect. The aims of this study were to investigate whether cordycepin (Cor) could reverse multidrug resistance (MDR) in NSCLC and to explore the underlying mechanisms.Methods: Cell proliferation and apoptosis were analyzed in NSCLC cell lines in vitro and in vivo, parental and DDP-resistant A549 cells, treated with DDP alone or combination with Cor. Proteins of different signaling pathways were investigated between DDP-sensistive and -insensitive A549 cell lines by GO terms and KEGG analysis, and perturbations of the MAPK and PI3K-AKT signaling pathways were evaluated by western blot. Results: Our data showed that Cor enhanced DDP inhibition of cell proliferation and promotion of apoptosis markedly compared to DDP alone group in both A549 and A549DDP. The synergic actions were associated with activation of AMPK and inhibition of AKT, mTOR and downstream P709S6K, S6 phosphorylation in the AKT pathway.Conclusion: Cor/DDP combination has synergistic effect on inhibiting proliferation and promoting apoptosis of NSCLC cells in the presence or absence of DDP resistance.

scholarly journals IL-13 promotes in vivo neonatal cardiomyocyte cell cycle activity and heart regeneration

2019 ◽  
Vol 316 (1) ◽  
pp. H24-H34 ◽  
Author(s):  
Dylan J. Wodsedalek ◽  
Samantha J. Paddock ◽  
Tina C. Wan ◽  
John A. Auchampach ◽  
Aria Kenarsary ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Signaling Pathways ◽  
Rna Sequencing ◽  
Akt Signaling ◽  
Heart Regeneration ◽  
Newborn Mice ◽  
Neonatal Cardiomyocyte

There is great interest in identifying signaling mechanisms by which cardiomyocytes (CMs) can enter the cell cycle and promote endogenous cardiac repair. We have previously demonstrated that IL-13 stimulated cell cycle activity of neonatal CMs in vitro. However, the signaling events that occur downstream of IL-13 in CMs and the role of IL-13 in CM proliferation and regeneration in vivo have not been explored. Here, we tested the role of IL-13 in promoting neonatal CM cell cycle activity and heart regeneration in vivo and investigated the signaling pathway(s) downstream of IL-13 specifically in CMs. Compared with control, CMs from neonatal IL-13 knockout (IL-13−/−) mice showed decreased proliferative markers and coincident upregulation of the hypertrophic marker brain natriuretic peptide ( Nppb) and increased CM nuclear size. After apical resection in anesthetized newborn mice, heart regeneration was significantly impaired in IL-13−/− mice compared with wild-type mice. Administration of recombinant IL-13 reversed these phenotypes by increasing CM proliferation markers and decreasing Nppb expression. RNA sequencing on primary neonatal CMs treated with IL-13 revealed activation of gene networks regulated by ERK1/2 and Akt. Western blot confirmed strong phosphorylation of ERK1/2 and Akt in both neonatal and adult cultured CMs in response to IL-13. Our data demonstrated a role for endogenous IL-13 in neonatal CM cell cycle and heart regeneration. ERK1/2 and Akt signaling are important pathways known to promote CM proliferation and protect against apoptosis, respectively; thus, targeting IL-13 transmembrane receptor signaling or administering recombinant IL-13 may be therapeutic approaches for activating proregenerative and survival pathways in the heart. NEW & NOTEWORTHY Here, we demonstrate, for the first time, that IL-13 is involved in neonatal cardiomyocyte cell cycle activity and heart regeneration in vivo. Prior work has shown that IL-13 promotes cardiomyocyte cell cycle activity in vitro; however, the signaling pathways were unknown. We used RNA sequencing to identify the signaling pathways activated downstream of IL-13 in cardiomyocytes and found that ERK1/2 and Akt signaling was activated in response to IL-13.

scholarly journals Pharmacologic Inhibition of DYRK1A Results in Hyperactivation and Hyperphosphorylation of MYC and ERK Rendering KMT2A-R ALL Cells Sensitive to BCL2 Inhibition

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 506-506
Author(s):  
Christian Hurtz ◽  
Gerald Wertheim ◽  
John Chukinas ◽  
Joseph Patrick Loftus ◽  
Sung June Lee ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
B Cell ◽  
Cell Lines ◽  
Research Funding ◽  
Crispr Screen ◽  
Cycle Regulation ◽  
Pharmacologic Inhibition

Abstract Background: KMT2A-rearranged (R) ALL is a high-risk disease with a frequency of 75% in infants and 10% in children and adults with ALL and is associated with chemoresistance, relapse, and poor survival. Current intensive multiagent chemotherapy regimens induce significant side effects, yet fail to cure many patients, demonstrating continued need for novel therapeutic approaches. We performed a kinome-wide CRISPR screen and identified that DYRK1A is specifically required for the survival of KMT2A-R ALL cell. DYRK1A is a member of the dual-specificity tyrosine phosphorylation-regulated kinase family and has been reported as negatively regulator of cell proliferation. Results: We performed a kinome-wide CRISPR screen in human ALL cell lines and PDX models and identified DYRK1A as a novel target in KMT2A-R ALL. DYRK1A is a serine-threonine kinase with a proposed, but poorly defined role in cell cycle regulation. We performed a meta-analysis of multiple ChIP-Seq experiments and identified that oncogenic KMT2A fusions directly bind to the DYRK1A promoter. Our RT-PCR and Western blot analyses of KMT2A-R ALL cells treated with a menin inhibitor (MI-503) to disrupt the transcriptional activity of the KMT2A-R complex resulted in the downregulation of DYRK1A, indicating that DYRK1A is directly regulated by the KMT2A fusion complex. We further observed that pharmacologic inhibition of DYRK1A with EHT1610 induced potent leukemic cell growth inhibition in vitro and in vivo, demonstrating that DYRK1A could be a new therapeutic target in KMT2A-R ALL cells. To further elucidate the mechanism of DYRK1A function, we treated several KMT2A-R ALL cell lines in vitro with EHT1610, which surprisingly resulted in the upregulation of MYC and hyperphosphorylation of the RAS/MAPK target ERK. Given that ERK hyperactivation stops B cell proliferation during early B cell development to allow them to rearrange their B cell receptor, we hypothesized that cell cycle inhibition upon ERK hyperactivation remains as a conserved mechanism of cell cycle regulation in KMT2A-R ALL. Strikingly, combining DYRK1A inhibition with the MEK inhibitor trametinib antagonistically rescued KMT2A-R ALL cell proliferation, indicating that ERK hyperactivation is the main driver of DYRK1A inhibitor mediated cell cycle arrest. Given that DYRK1A inhibitor does not induce apoptosis and cells restart cell proliferation after EHT1610 withdrawal we concluded that a DYRK1A monotherapy may not be an ideal new treatment option. However, it has been reported that increased MYC activity induces the accumulation of BIM in Burkitt's Lymphoma. Given the increased expression of MYC following DYRK1A inhibition we performed a new Western blot analysis and validated increased expression of BIM in our KMT2A-R ALL cell lines after EHT1610 treatment. To test if targeting the interaction of BIM with BCL2 will induce an apoptotic effect when combined with EHT1610, we treated four KMT2A-R ALL cell lines with increasing concentrations of EHT1610 and the BCL2 inhibitor venetoclax. Strikingly, the combination of DYRK1A inhibition with BCL2 inhibition synergistically killed KMT2A-R ALL cells. Conclusion: Our results validate DYRK1A as an important molecule to regulate cell proliferation via inhibition of MYC and ERK. Targeting DYRK1A results in the accumulation of BIM, which renders the cells sensitive to BCL2 inhibition via venetoclax. While further in vivo studies are needed, we predict that combining DYRK1A inhibition with venetoclax may be a novel precision medicine strategy for the treatment of KMT2A-R ALL. Figure 1 Figure 1. Disclosures Crispino: Forma Therapeutics: Research Funding; Scholar Rock: Research Funding; MPN Research Foundation: Membership on an entity's Board of Directors or advisory committees; Sierra Oncology: Consultancy. Tasian: Aleta Biotherapeutics: Consultancy; Gilead Sciences: Research Funding; Kura Oncology: Consultancy; Incyte Corporation: Research Funding. Carroll: Incyte Pharmaceuticals: Research Funding; Janssen Pharmaceutical: Consultancy.

Role of IGF-1R inhibition on an Src-family kinase bypass resistance pathway: A rational basis for cotargeting IGF-1R and Src kinase in pediatric sarcomas?

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. 10025-10025
Author(s):  
Xiaolin Wan ◽  
Choh L Yeung ◽  
Christine Heske ◽  
Arnulfo Mendoza ◽  
Lee J. Helman
Keyword(s):  
Signaling Pathways ◽  
Cell Lines ◽  
Kinase Inhibitors ◽  
Src Kinase ◽  
Es Cell ◽  
Src Family Kinase ◽  
Pediatric Sarcomas

10025 Background: Dysregulation of IGF signaling plays a fundamental role in oncogenesis in pediatric sarcomas. We recently completed a Phase II study targeting the IGFI receptor signaling pathway in refractory Ewing’s and other sarcomas. We demonstrated an objective response rate of 16 percent, but most responses were transient lasting less than 18 weeks. The majority of patients, even those with initial responses, do not have long term benefit from IGFIR blockade, indicating the presence of an innately resistant tumor mass or the recruitment of compensatory pathways allowing for continued growth. To improve on these responses, we have been probing these tumors to identify other critical pathways that might allow combined targeting approaches. Methods: Multiple RMS and ES cell lines were treated with IGF1R kinase inhibitors and assayed for up-regulation of various signaling pathways. Combination treatment with IGF1R inhibitors and inhibitors of additional signaling pathways were then tested in vitro and in vivo using standard techniques. For in vivo xenograft studies, treatments began 11 days following orthotopic injection of tumor cells. Results: We have identified repid up-regulation of Src family kinase (SFK) signaling within 4 hours of IGF1R blockade in both RMS and ES cell lines. Of note, combined treatment with IGF1R Ab plus IGF1R kinase inhibitors most potently upregulated SFK signaling. Based on these findings, we tested combined IGF1R blockade with SFK inhibition using the commercially available drug, dasatinib. We show that dual blockade of IGF1R and SFK pathways were synergistic in vitro. Furthermore, in xenograft models of RMS, the combination IGF1R and SFK inhibition led to long-term disease free status for at least 90 days in some mice, never seen in our hands previously using these models. Conclusions: This work identified that IGF-1R inhibition induced activation of Src kinase that may act as a by-pass pathway. Synergistic activity of IGF-1R and SFK kinase inhibitors was observed in vitro and in vivo. Dual IGFI and SFK kinase inhibition may lead to improved therapeutic outcomes.

Preclinical study of MEK1/2 inhibitor AZD6244 combined with gemcitabine for treatment of biliary cancer.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 240-240
Author(s):  
Junyao Xu ◽  
Jennifer J. Knox ◽  
Ming Sound Tsao ◽  
Eric Xueyu Chen ◽  
Pinjiang Cao ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Preclinical Study ◽  
Erk Signaling ◽  
Therapeutic Effects ◽  
Biliary Cancer

240 Background: MEK1/2 is an integral component of the Ras/Raf/MEK/ERK signaling pathway, implicated in uncontrolled cell proliferation and cell survival, a key hallmark of cancer. AZD6244, a novel inhibitor of MEK1/2, is currently completing Phase II clinical trials in biliary cancer, with modest antitumor activity observed as monotherapy. Gemcitabine is a cytotoxic drug commonly used in biliary cancer therapy but many patients showed early resistance. In this preclinical study, we investigated the sequence-dependent antitumor effects of AZD6244 combined with gemcitabine in biliary cancer models. Methods: Two biliary cancer cell lines (EGI-1 and TFK-1) were used. In vitro the effects of single drug or three combination protocols(concurrently; AZD6244 followed by GEM or Gem followed by AZD6244) on cell proliferation, DNA synthesis, and cell cycle distribution were evaluated by MTS, clonogenic assay, EdU uptake and flow cytometry. Drug interactions were analyzed by Chou-Talaly method. In vivo, 4 tumor models subcutaneously xenografted in SCID mice from the two cell lines and 2 human patients were set up to compare the therapeutic effects of different sequence-scheduled combinations. Results: AZD6244 caused G1-S cell cycle arrest in biliary cancer cells in vitro and in vivo, and this effect is correlated with the MEK/ERK signaling pathway blocking. Synchronized progression of the population through S phase were observed in 15h after removal of AZD6244 in cell culture or 48h after final dose of acute AZD6244 treatment in vivo. Antagonistic or additive effects was observed in vitro when combination were given as concurrently(CI=2.03~2.46) or Gem followed by AZD6244(CI=1.34~1.78). In contrast, a synergistic antiproliferative activity was obtained when AZD6244 was given first followed by a drug-free interval before Gem treatment (CI=0.53~0.69). In vivo, the best therapeutic effects were obtained with the sequence of AZD6244 followed by Gem, compared with concurrent or reverse sequence. Conclusions: This study provides a sound rationale for a Phase II trial of a potentially synergistic sequence of MEK inhibitor AZD6244 followed by gemcitabine in patients with advanced biliary cancer.

scholarly journals SCUBE3 Downregulation Modulates Hepatocellular Carcinoma By Inhibiting CCNE1 Via TGFβ/PI3K/AKT/GSK3β Pathway

2021 ◽  
Author(s):  
Pan xu ◽  
Aoran Luo ◽  
Chuan Xiong ◽  
Hong Ren ◽  
Yan Liang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Akt Signaling ◽  
Cell Counting ◽  
Pathway Enrichment Analysis ◽  
Akt Signaling Pathway

Abstract Objectives: We aimed to verify the role of signal peptide-CUB-EGF-like domain-containing protein3 (SCUBE3) in the hepatocellular carcinoma (HCC) progression.Methods: The role·of SCUBE3 in HCC cell proliferation, apoptosis, and cell cycle in vitro were investigated using MTT assay, 5-ethynyl-2´-deoxyuridine assay (EDU), Celigo cell counting assay, Caspase3/7 activity assay, and flow cytometry. The effect of SCUBE3 on HCC cell proliferation in vivo was investigated by a xenograft tumor model in nude mice. The related mechanisms were further investigated.Results: SCUBE3 was upregulated in HCC tissues and cell lines. Knockdown of SCUBE3 inhibited proliferation, promoted apoptosis, and induced cell cycle arrest in HCC cell lines in vitro and vivo. Screening of cell cycle-related proteins revealed CCNL2, CDK6, CCNE1, and CCND1 exhibited a significantly different expression profile. We found that SCUBE3 may promote the proliferation of HCC cells by regulating CCNE1 expression. The pathway enrichment analysis showed that the TGFβ signaling pathway and the PI3K/AKT signaling pathway were significantly altered. Co-immunoprecipitation results showed that SCUBE3 binds to the TGFβRII receptor. SCUBE3 knockdown inhibited the PI3K/AKT signaling pathway and the phosphorylation of GSK3β to inhibit its kinase activity.Conclusions：SCUBE3 promotes HCC development by regulating CCNE1 via TGFβ/PI3K/AKT/GSK3βpathway. In addition, SCUBE3 may be a new molecular target for clinical diagnosis and treatment of HCC.

scholarly journals Lenvatinib Inhibits Intrahepatic Cholangiocarcinoma Growth via Gadd45a-Mediated Cell Cycle Arrest

2021 ◽  
Author(s):  
Xia Yan ◽  
Dan Wang ◽  
Liping Zhuang ◽  
Peng Wang ◽  
Zhiqiang Meng ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Cycle Arrest ◽  
Cell Lines ◽  
Intrahepatic Cholangiocarcinoma ◽  
Primary Liver Cancer ◽  
Transcriptional Profiling ◽  
Cycle Arrest

Abstract Background: Intrahepatic cholangiocarcinoma (ICC) is the second most common primary liver cancer, and its 5-year survival rate is less than 10%. Fibroblast growth factor receptor (FGFR) changes have been observed in 6%-50% of ICC patients, and patients with FGFR mutations have been shown to have more inert tumour biological activity than patients with wild-type FGFRs. Thus, as a pan-FGFR inhibitor, lenvatinib is supposed to play an anti-tumour role in ICC. However, no relevant experiments have been reported.Methods: Patients derived xenograft (PDX) model and cell line derived xenograft (CDX) model were both used for the in vivo study. For in vivo work, ICC cell lines were applied to analyse the effect of Lenvatinib on cell proliferation, cell cycle progression, apoptosis, and the molecular mechanism.Reaults: In the present study, we found that lenvatinib dramatically hindered in vivo tumor growth in ICC patient-derived xenograft models. In addition, by using in vitro experiments in ICC cell lines, we found that lenvatinib dose- and time-dependently inhibited the proliferation of ICC cells and induced cell cycle arrest in the G0/G1 phase. Transcriptional profiling analysis further applied indicated that lenvatinib might inhibit cell proliferation through the induction of cell-cycle arrestment via activating of Gadd45a, it was evidenced by that the knockout of Gadd45a significantly attenuated the cycle arrest induced by lenvatinib, as well as the inhibitory effect of lenvatinib on ICC.Conclusion: Our work firstly found that lenvatinib exerted excellent antitumor effect on ICC, mainly via inducing Gadd45a mediated cell cycle arrest. Our work provides evidence and a rationale for the future use of lenvatinib in the treatment of ICC.

scholarly journals SCUBE3 downregulation modulates hepatocellular carcinoma by inhibiting CCNE1 via TGFβ/PI3K/AKT/GSK3β pathway

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Pan Xu ◽  
Aoran Luo ◽  
Chuan Xiong ◽  
Hong Ren ◽  
Liang Yan ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Cycle ◽  
Cell Proliferation ◽  
Cell Lines ◽  
Signalling Pathway ◽  
Cell Counting ◽  
Pathway Enrichment Analysis

Abstract Objectives We aimed to verify the role of signal peptide-CUB-EGF-like domain-containing protein3 (SCUBE3) in the hepatocellular carcinoma (HCC) progression. Methods The role of SCUBE3 in HCC cell proliferation, apoptosis, and cell cycle in vitro were detected using MTT assay, colony formation assay, 5-ethynyl-2´-deoxyuridine assay (EDU), Celigo cell counting assay, Caspase3/7 activity assay, and flow cytometry. The effect of SCUBE3 on HCC cell proliferation in vivo was inspected by a xenograft tumour model in nude mice. The related mechanisms were further studied. Results The level of SCUBE3 was upregulated in HCC tissues and cell lines. Knockdown of SCUBE3 inhibited proliferation, promoted apoptosis, and induced cell cycle arrest in HCC cell lines in vitro and in vivo. Screening of cell cycle-related proteins revealed that CCNL2, CDK6, CCNE1, and CCND1 exhibited a significantly different expression profile. We found that SCUBE3 may promote the proliferation of HCC cells by regulating CCNE1 expression. The pathway enrichment analysis showed that the TGFβ signalling pathway and the PI3K/AKT signalling pathway were significantly altered. Co-immunoprecipitation results showed that SCUBE3 binds to the TGFβRII receptor. SCUBE3 knockdown inhibited the PI3K/AKT signalling pathway and the phosphorylation of GSK3β to inhibit its kinase activity. Conclusions SCUBE3 promotes HCC development by regulating CCNE1 via TGFβ/PI3K/AKT/GSK3β pathway. In addition, SCUBE3 may be a new molecular target for the clinical diagnosis and treatment of HCC.

SRPK1 promotes cell proliferation and tumor growth of osteosarcoma through activation of the NF-κB signaling pathway

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yubao Gong ◽  
Chen Yang ◽  
Zhengren Wei ◽  
Jianguo Liu
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Tumor Growth ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Expression Level ◽  
Osteosarcoma Cell ◽  
Human Osteosarcoma

Abstract To explore the expression and the functions of SRPK1 in osteosarcoma, we retrieved transcription profiling dataset by array of human bone specimens from patients with osteosarcoma from ArrayExpress (accession E-MEXP-3628) and from Gene Expression Omnibus (accession GSE16102) and analyzed expression level of SRPK1 and prognostic value in human osteosarcoma. Then we examined the effect of differential SRPK1 expression levels on the progression of osteosarcoma, including cell proliferation, cell cycle, apoptosis, and investigated its underlying molecular mechanism using in vitro osteosarcoma cell lines and in vivo nude mouse xenograft models. High expression level of SRPK1 was found in human osteosarcoma tissues and cell lines as compared to the normal bone tissues and osteoblast cells, and predicted poor prognosis of human osteosarcoma. Overexpression of SRPK1 in osteosarcoma U2OS cells led to cell proliferation but inhibition of apoptosis. In contrast, knockdown of SRPK1 in HOS cells impeded cell viability and induction of apoptosis. Moreover, silencing SRPK1 inhibited osteosarcoma tumor growth in nude mice. Mechanistic studies revealed that SRPK1 promoted cell cycle transition in osteosarcoma cells and activation of NF-κB is required for SRPK1 expression and its pro-survival signaling. SRPK1 promoted human osteosarcoma cell proliferation and tumor growth by regulating NF-κB signaling pathway.

scholarly journals BRD4 PROTAC degrader ARV-825 inhibits T-cell acute lymphoblastic leukemia by targeting 'Undruggable' Myc-pathway genes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shuiyan Wu ◽  
You Jiang ◽  
Yi Hong ◽  
Xinran Chu ◽  
Zimu Zhang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Acute Lymphoblastic Leukemia ◽  
Caspase 3 ◽  
Lymphoblastic Leukemia ◽  
Rna Seq ◽  
Cell Acute Lymphoblastic Leukemia ◽  
Bet Protein

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.

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