scholarly journals DDRE-24. ACQUIRED RESISTANCE TO TARGETED INHIBITORS IN EGFR-DRIVEN GLIOBLASTOMA: IDENTIFICATION OF DUAL KINASE TARGETS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii66-ii66
Author(s):  
Abigail Shelton ◽  
Erin Smithberger ◽  
Madison Butler ◽  
Allie Stamper ◽  
Ryan Bash ◽  
...  
Keyword(s):  
Acquired Resistance ◽  
Genetically Engineered ◽  
Differentially Expressed ◽  
Cross Resistance ◽  
Rna Seq ◽  
Cdkn2a Deletion ◽  
Egfr Tki ◽  
Resistant Cells

Abstract Glioblastoma (GBM) is a devastating primary brain tumor with 5-year survival < 5%. CDKN2A deletion (~60%) and EGFR amplification (55–60%) mutations frequently co-occur in these tumors. EGFR is an attractive therapeutic target due to its mutational frequency and availability of multiple brain-penetrant tyrosine kinase inhibitors (TKI). Several EGFR TKI have failed clinically, due in part to acquired resistance. To mechanistically examine this type of resistance, we used genetically engineered mouse astrocytes harboring Cdkn2a deletion and EGFRvIII, a common (35%) activating mutation. Resistant cells were generated via chronic exposure to gefitinib or erlotinib, either in vitro or in vivo. Resistance to these first-generation EGFR TKI conferred cross resistance (up to 36-fold ΔIC50) to a panel of second- and third-generation TKI relative to sensitive parental lines. Moreover, integrated RNA sequencing (RNA-seq) and chemical proteomics (multiplexed inhibitor beads and mass spectrometry (MIB-MS)) showed that the kinase transcriptome and proteome were rewired in resistant cells: 113 of ~300 detected kinases were differentially expressed (p< 0.05). We then used these techniques to examine acute (≤ 48 h) kinome changes in both sensitive and resistant cells upon treatment with a CNS-penetrant, second-generation EGFR TKI, afatinib. Whereas exposure of treatment-naïve, sensitive cells to afatinib significantly rewired the kinome (120 differentially expressed kinases), the response of resistant cells to drug re-challenge was significantly blunted (13 differentially expressed kinases). A subset of expressed kinases (35 of 263) dynamically responded to afatinib in both sensitive and resistant cells. Overall, upregulated kinases include those implicated in the biology of gliomas (Bmx, Fgfr2) and of other cancers (Pdgfrb, Mapk3/4, Ddr1/2, Pdk2). These kinases thus represent putative druggable targets for dual inhibition therapy. Integrated kinome profiling using MIB-MS and RNA-seq in GBM models with defined mutational profiles provides a powerful framework to identify novel therapeutic targets that could significantly alter current treatment paradigms.

scholarly journals Global Transcriptome Profiling Identifies a Key Mir-185-PAK6 Axis That Promotes Survival of Leukemic Stem Cells and Drug-Insensitive Blasts in BCR-ABL+ Human Leukemia

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 931-931
Author(s):  
Andrew Wu ◽  
Lin Hanyang ◽  
Katharina Rothe ◽  
Min Chen ◽  
Jens Ruschmann ◽  
...  
Keyword(s):  
Expression Profiles ◽  
Transcriptome Profiling ◽  
Differentially Expressed ◽  
Leukemic Stem Cells ◽  
Cd34 Cells ◽  
Differentially Expressed Mirnas ◽  
Resistant Cells

Abstract Chronic myeloid leukemia (CML) stem/progenitor cells and BCR-ABL+ acute lymphoblastic leukemia (ALL) blast cells are insensitive to tyrosine kinase inhibitor (TKI) monotherapies. These cells rapidly generate therapy-resistant clones in vitro and in vivo and are often responsible for disease relapse. Therefore, identification of predictive biomarkers and novel treatments that target key molecular events active in leukemic stem cells (LSCs) are needed. MicroRNAs (miRNAs) are small molecules that regulate the gene expression network and are highly deregulated in many cancers. Through global transcriptome profiling, we have recently identified 66 differentially expressed miRNAs in pre-treatment CD34+ stem/progenitor cells from CML patients (n=6) compared to healthy bone marrow (NBM) controls (n=3, adjusted P<0.05); 26 differentially expressed miRNAs were identified between subsequent IM-nonresponders and IM-responders (P<0.05). 21 differentially expressed miRNAs were successfully validated in additional IM-responders (n=11), IM-nonresponders (n=11) and NBM (n=11). Interestingly, miR-185 was discovered to be one of the most highly deregulated miRNAs, with significant reduction in CD34+ cells from IM-nonresponders compared to IM-responders (p=0.0006). This significant change was further demonstrated in CD34+ cells from CML patients (n=60) before and after 3-month TKI nilotinib treatment in a clinical trial (p<0.05). We further demonstrated that miR-185 functions as a tumor suppressor; its restored expression by lentiviral transduction in CD34+ IM-nonresponder cells significantly impaired survival of these cells and sensitized them to TKI treatment in vitro. Restored miR-185 expression in BCR-ABL+ ALL blasts led to a profound decrease in leukemia burden and significantly enhanced survival compared to controls in vivo (median survival 65 vs. 47 days, P=0.0005). Strikingly, mice injected with miR-185-transduced cells and treated with dasatinib (DA) survived much longer than recipients of control cells treated with DA (median survival 83 vs. 60 days, P=0.0018). Moreover, restoration of miR-185 expression combined with DA treatment greatly reduced in vivo long-term regenerative activity of LSCs from IM-nonresponders as compared to control cells treated with DA in NRG mice (<0.2% vs. 5% GFP+ patient cells in the BM, 25 weeks post-transplantation). We observed not only a marked reduction in GFP+CD34+ cells, but also a near elimination of GFP+CD34+CD38- LSCs that were transduced with miR-185 and treated with DA compared to control cells treated with DA, indicating that restored miR-185 expression combined with DA preferentially prevents the growth of patient-derived long-term leukemia-initiating cells in vivo. Several miRNA target genes were further identified by integrating miRNA expression profiles with gene expression profiles from the same patient samples using strand-specific RNA-seq. Based on three out of six prediction algorithms (mirBase, TargetScan, miRanda, tarBase, mirTarget2, and PicTar), PAK6, a serine/threonine-protein kinase, was found to be highly expressed in CD34+ IM-nonresponder cells compared to IM-responders (p<0.003), which correlated with reduced expression of miR-185 in these cells (p=0.0002). PAK6 was confirmed as a target gene of miR-185 by a luciferase reporter assay. Western blot analysis showed that restored miR-185 expression caused a marked decrease in protein levels of PAK6 in miR-185-transduced cells and suppression of PAK6 reduced viability of these cells. These results indicate that PAK6 is a critical target of miR-185, and that loss of miR-185 expression in CML may lead to up-regulation of PAK6, which in turn contributes to disease progression and drug resistance. Indeed, the use of a pre-clinically validated pan PAK inhibitor (PF-3758309) significantly inhibited the growth of IM-resistant cells and CD34+ IM-nonresponder cells and these effects could be enhanced by TKIs (p<0.05). Mechanistically, we observed that p-ERK and p-AKT were significantly reduced in PAK6 knockdown or miR185-restored IM-resistant cells in response to IM treatment. Thus, we infer that downregulation of PAK6 may sensitize TKI-resistant cells to TKI therapy through inhibition of the RAS/MAPK pathway. Taken together, PAK6, a novel target of miR-185, emerges as an attractive druggable target for combination therapy of TKI-resistant patients. Disclosures No relevant conflicts of interest to declare.

CARD8/BCL-2 cascade in early adaptive drug resistant tumor escape against targeted inhibitors in NSCLC.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22032-e22032
Author(s):  
Rakesh K. Bagai ◽  
Wei Zhang ◽  
Patrick Leahy ◽  
Lihong Yin ◽  
Patrick C. Ma
Keyword(s):  
Lung Cancer ◽  
Drug Resistance ◽  
Expression Analysis ◽  
Xenograft Model ◽  
Tumor Escape ◽  
Apoptosis Pathway ◽  
Egfr Tki ◽  
Resistant Cells

e22032 Background: Lung cancer targeted therapy is largely limited by inevitable recurrent resistant disease after initial response to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), typically accompanied with divergent late acquired resistance mechanisms. We now focused on studying the emergence of early adaptive resistance to uncover attractive therapeutic targets to overcome drug resistance. Methods: HCC827 cells were treated with EGFR-TKI (0-9 days) with apoptosis pathway-specific QPCR array and TLVM analysis performed. MTS and crystal violet assays were performed. Western blot analysis was performed to examine prosurvival signaling developed against erlotinib, alone or in combination with MET inhibitor SU11274. IHC was performed on lung cancer tumor microarray (TMA) using BCL-2 and caspase-recruitment domain-containing protein 8 (CARD8) antibodies and graded (4 tier scoring system). NSCLC cell lines and murine xenograft models (HCC827, H1975) were developed for resistance biomarkers expression analysis in pre-/post-TKI treatment using anti-human CARD8, p-STAT3 and BCL-2 antibodies. Results: We characterized the emergence of early resistant lung cancer cells in escape against targeted TKIs with 100-fold higher IC50 in adaptive drug resistance. The resistant cells that evaded EGFR-TKI based targeted inhibition exhibited MET-independent induction of CARD8 and STAT3/BCL-2 mitochondrial prosurvival signaling in cellular quiescence, and inhibited cytoskeletal functions. Expression analysis studies demonstrated common tumor-associated expression of CARD8 but relatively low BCL-2 level in NSCLC. In vitro cell line studies suggest that CARD8 induction was preceded by a resurgence of STAT3 activation. In vivo xenograft model (HCC827/erlotinib; H1975/erlotinib+ SU11274) also verified upregulated CARD8/BCL-2 activation within early resistant cells. Conclusions: Resistant tumor cells that evaded EGFR inhibitors, alone or in combination with MET inhibitors, exhibited increased expression of CARD8-STAT3/BCL-2 prosurvival signaling cascade. Further studies to define the mechanism of CARD8 in promoting adaptive tumor drug resistance would be warranted.

Role of sphingosine kinase 1 (SphK1) on cetuximab resistance in colorectal cancer models.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13509-e13509
Author(s):  
Roberto Bianco ◽  
Roberta Rosa ◽  
Lucia Nappi ◽  
Luigi Formisano ◽  
Vincenzo Damiano ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Anticancer Agents ◽  
Acquired Resistance ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 1 ◽  
Mutational Status ◽  
Resistant Cells

e13509 Background: Although EGFR inhibitors, such as the mAb cetuximab, represent an effective strategy in colorectal cancer (CRC), the clinical use of these agents is limited by intrinsic or acquired resistance. Alterations in the ‘sphingolipid rheostat’, or the balance between the proapoptotic molecule ceramide and the mitogenic factor sphingosine-1-phosphate (S1P), due to overactivation of sphingosine kinase 1 (SphK1), have been involved in the regulation of resistance to anticancer agents. Since some studies described cross-talks between SphK1 and EGFR-dependent signalling pathways, we investigated the contribution of SphK1 to cetuximab resistance in CRC models. Methods: We used CRC cell lines with both intrinsic or acquired resistance to cetuximab. In these models, we analyzed SphK1 expression/activation by using different tools, including the available drug fingolimod (FTY720), both in vitro and in vivo. We confirmed our data through a tissue microarray (TMA)-based analysis on CRC tissues. Results: SphK1 is overexpressed in CRC cells resistant to cetuximab. Higher doses of N,N-dimethylsphingosine (DMS), a potent competitive inhibitor of SphK1, are needed to achieve complete enzyme saturation and survival inhibition in resistant cells. Moreover, ceramide induces apoptosis less efficiently in resistant than in sensitive cells, consistently with the idea that increased SphK1 levels mediate S1P synthesis by ceramide in resistant cells. SphK1 contribution to resistance is supported by the demonstration that SphK1 inhibition by DMS or silencing via siRNA in resistant cells restores sensitivity to cetuximab, whereas exogenous SphK1 overexpression in wild-type cells confers resistance. Re-sensitization to cetuximab is observed after treatment with fingolimod, a S1P receptor inhibitor, both in vitro and in nude mice xenografted with CRC cells. Finally, a TMA-based analysis on CRC tissues revealed that SphK1 expression is related to K-Ras mutational status, a well-known determinant of cetuximab resistance. Conclusions: Our data could clarify the role of SphK1 in the onset of resistance to cetuximab, thus suggesting SphK1 inhibition as a part of novel targeting strategies for resistant cancer patients.

Antihormone induced compensatory signalling in breast cancer: an adverse event in the development of endocrine resistance

2011 ◽  
Vol 5 (2) ◽  
Author(s):  
Julia M.W. Gee ◽  
Robert I. Nicholson ◽  
Denise Barrow ◽  
Carol M. Dutkowski ◽  
Lindy Goddard ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tyrosine Kinases ◽  
Acquired Resistance ◽  
Endocrine Resistance ◽  
Clinical Relapse ◽  
Her2 Breast Cancer ◽  
Targeted Inhibitors ◽  
Resistant Cells

AbstractUsing MCF7 breast cancer cells, it has been shown that antihormones promote expression/activity of oestrogen-repressed tyrosine kinases, notably EGFR, HER2 and Src. These inductive events confer responsiveness to targeted inhibitors (e.g., gefitinib, trastuzumab, saracatinib). We observed that these antihormone-induced phenomena are common to ER+HER2– and ER+HER2+ breast cancer models in vitro, where targeting of EGFR, HER2 or Src alongside antihormone improves antitumour response and delays/prevents endocrine resistance. Such targeted inhibitors also subvert acquired endocrine resistant cells which retain increased EGFR, HER2 and Src (e.g., TAMR and FASR models derived after 6–12 months of tamoxifen or Faslodex treatment). Thus, antihormone-induced tyrosine kinases comprise “compensatory signalling” crucial in limiting maximal initial antihormone response and subsequently driving acquired resistance in vitro. However, despite such convincing preclinical findings from our group and others, clinical trials examining equivalent antigrowth factor strategies have proved relatively disappointing. Our new studies deciphering underlying causes reveal that further antihormone-promoted events could be pivotal in vivo. Firstly, Faslodex induces HER3 and HER4 which sensitise ER+ cells to heregulin, a paracrine growth factor that overcomes endocrine response and diminishes antitumour effect of agents targeting EGFR, HER2 or Src alongside antihormone. Secondly, extended antihormone exposure (experienced by ER+ cells prior to adjuvant clinical relapse) can “reprogramme” the compensatory kinase profile in vitro, hindering candidate antigrowth factor targeting of endocrine resistance. Faslodex resistant cells maintained with this antihormone for 3 years in vitro lose EGFR/HER2 dependency, gaining alternative mitogenic/invasion kinases. Deciphering these previously unrecognised antihormone-induced events could provide superior treatments to control endocrine relapse in the clinic.

scholarly journals PKCδ-mediated SGLT1 upregulation confers the acquired resistance of NSCLC to EGFR TKIs

Oncogene ◽  
2021 ◽  
Author(s):  
Chia-Hung Chen ◽  
Bo-Wei Wang ◽  
Yu-Chun Hsiao ◽  
Chun-Yi Wu ◽  
Fang-Ju Cheng ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Kinase Inhibitors ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Tki Treatment ◽  
Nsclc Patients ◽  
Egfr Tki ◽  
Egfr Tkis

AbstractThe tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) have been widely used for non-small cell lung cancer (NSCLC) patients, but the development of acquired resistance remains a therapeutic hurdle. The reduction of glucose uptake has been implicated in the anti-tumor activity of EGFR TKIs. In this study, the upregulation of the active sodium/glucose co-transporter 1 (SGLT1) was found to confer the development of acquired EGFR TKI resistance and was correlated with the poorer clinical outcome of the NSCLC patients who received EGFR TKI treatment. Blockade of SGLT1 overcame this resistance in vitro and in vivo by reducing glucose uptake in NSCLC cells. Mechanistically, SGLT1 protein was stabilized through the interaction with PKCδ-phosphorylated (Thr678) EGFR in the TKI-resistant cells. Our findings revealed that PKCδ/EGFR axis-dependent SGLT1 upregulation was a critical mechanism underlying the acquired resistance to EGFR TKIs. We suggest co-targeting PKCδ/SGLT1 as a potential strategy to improve the therapeutic efficacy of EGFR TKIs in NSCLC patients.

scholarly journals Establishment and Characterization of an Irinotecan-Resistant Human Colon Cancer Cell Line

2021 ◽  
Vol 10 ◽  
Author(s):  
Zhuo-Xun Wu ◽  
Yuqi Yang ◽  
Leli Zeng ◽  
Harsh Patel ◽  
Letao Bo ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Drug Resistance ◽  
Cell Line ◽  
Acquired Resistance ◽  
Human Colon ◽  
Cross Resistance ◽  
Human Colon Cancer ◽  
Active Efflux

Colorectal cancer (CRC) is a leading cause of cancer-related deaths worldwide. Irinotecan is widely used as a chemotherapeutic drug to treat CRC. However, the mechanisms of acquired resistance to irinotecan in CRC remain inconclusive. In the present study, we established a novel irinotecan-resistant human colon cell line to investigate the underlying mechanism(s) of irinotecan resistance, particularly the overexpression of ABC transporters. The irinotecan-resistant S1-IR20 cell line was established by exposing irinotecan to human S1 colon cancer cells. MTT cytotoxicity assay was carried out to determine the drug resistance profile of S1-IR20 cells. The drug-resistant cells showed about 47-fold resistance to irinotecan and cross-resistance to ABCG2 substrates in comparison with S1 cells. By Western blot analysis, S1-IR20 cells showed significant increase of ABCG2, but not ABCB1 or ABCC1 in protein expression level as compared to that of parental S1 cells. The immunofluorescence assay showed that the overexpressed ABCG2 transporter is localized on the cell membrane of S1-IR20 cells, suggesting an active efflux function of the ABCG2 transporter. This finding was further confirmed by reversal studies that inhibiting efflux function of ABCG2 was able to completely abolish drug resistance to irinotecan as well as other ABCG2 substrates in S1-IR20 cells. In conclusion, our work established an in vitro model of irinotecan resistance in CRC and suggested ABCG2 overexpression as one of the underlying mechanisms of acquired resistance to irinotecan. This novel resistant cell line may enable future studies to overcome drug resistance in vitro and improve CRC treatment in vivo.

scholarly journals TAM family receptors in conjunction with MAPK signalling are involved in acquired resistance to PI3Kα inhibition in head and neck squamous cell carcinoma

2020 ◽  
Vol 39 (1) ◽  
Author(s):  
Kara M. Ruicci ◽  
Jalna Meens ◽  
Paul Plantinga ◽  
William Stecho ◽  
Nicole Pinto ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Cell Lines ◽  
Acquired Resistance ◽  
Pi3k Pathway ◽  
Drug Resistant ◽  
Mapk Signalling ◽  
Hnscc Cell ◽  
Resistant Cells

Abstract Background Aberrant activation of the phosphatidylinositol 3-kinase (PI3K) pathway is common in many malignancies, including head and neck squamous cell carcinoma (HNSCC). Despite pre-clinical and clinical studies, outcomes from targeting the PI3K pathway have been underwhelming and the development of drug resistance poses a significant barrier to patient treatment. In the present study, we examined mechanisms of acquired resistance to the PI3Kα inhibitor alpelisib (formerly BYL719) in HNSCC cell lines and patient-derived xenografts (PDXs). Methods Five unique PDX mouse models and three HNSCC cell lines were used. All cell lines and xenografts underwent genomic characterization prior to study. Serial drug treatment was conducted in vitro and in vivo to develop multiple, clinically-significant models of resistance to alpelisib. We then used reverse phase protein arrays (RPPAs) to profile the expression of proteins in parental and drug-resistant models. Top hits were validated by immunoblotting and immunohistochemistry. Flow cytometric analysis and RNA interference studies were then used to interrogate the molecular mechanisms underlying acquired drug resistance. Results Prolonged treatment with alpelisib led to upregulation of TAM family receptor tyrosine kinases TYRO3 and AXL. Importantly, a significant shift in expression of both TYRO3 and AXL to the cell surface was detected in drug-resistant cells. Targeted knockdown of TYRO3 and AXL effectively re-sensitized resistant cells to PI3Kα inhibition. In vivo, resistance to alpelisib emerged following 20–35 days of treatment in all five PDX models. Elevated TYRO3 expression was detected in drug-resistant PDX tissues. Downstream of TYRO3 and AXL, we identified activation of intracellular MAPK signalling. Inhibition of MAPK signalling also re-sensitized drug-resistant cells to alpelisib. Conclusions We have identified TYRO3 and AXL receptors to be key mediators of resistance to alpelisib, both in vitro and in vivo. Our findings suggest that pan-TAM inhibition is a promising avenue for combinatorial or second-line therapy alongside PI3Kα inhibition. These findings advance our understanding of the role TAM receptors play in modulating the response of HNSCC to PI3Kα inhibition and suggest a means to prevent, or at least delay, resistance to PI3Kα inhibition in order to improve outcomes for HNSCC patients.

scholarly journals 1592U89, a novel carbocyclic nucleoside analog with potent, selective anti-human immunodeficiency virus activity.

1997 ◽  
Vol 41 (5) ◽  
pp. 1082-1093 ◽  
Author(s):  
S M Daluge ◽  
S S Good ◽  
M B Faletto ◽  
W H Miller ◽  
M H St Clair ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Bioavailability ◽  
Human Peripheral Blood ◽  
Cross Resistance ◽  
Immunodeficiency Virus ◽  
Carbocyclic Nucleoside ◽  
Hiv 1 ◽  
In Cells

1592U89, (-)-(1S,4R)-4-[2-amino-6-(cyclopropylamino)-9H-purin-9-yl]-2-cyclo pentene-1-methanol, is a carbocyclic nucleoside with a unique biological profile giving potent, selective anti-human immunodeficiency virus (HIV) activity. 1592U89 was selected after evaluation of a wide variety of analogs containing a cyclopentene substitution for the 2'-deoxyriboside of natural deoxynucleosides, optimizing in vitro anti-HIV potency, oral bioavailability, and central nervous system (CNS) penetration. 1592U89 was equivalent in potency to 3'-azido-3'-deoxythymidine (AZT) in human peripheral blood lymphocyte (PBL) cultures against clinical isolates of HIV type 1 (HIV-1) from antiretroviral drug-naive patients (average 50% inhibitory concentration [IC50], 0.26 microM for 1592U89 and 0.23 microM for AZT). 1592U89 showed minimal cross-resistance (approximately twofold) with AZT and other approved HIV reverse transcriptase (RT) inhibitors. 1592U89 was synergistic in combination with AZT, the nonnucleoside RT inhibitor nevirapine, and the protease inhibitor 141W94 in MT4 cells against HIV-1 (IIIB). 1592U89 was anabolized intracellularly to its 5'-monophosphate in CD4+ CEM cells and in PBLs, but the di- and triphosphates of 1592U89 were not detected. The only triphosphate found in cells incubated with 1592U89 was that of the guanine analog (-)-carbovir (CBV). However, the in vivo pharmacokinetic, distribution, and toxicological profiles of 1592U89 were distinct from and improved over those of CBV, probably because CBV itself was not appreciably formed from 1592U89 in cells or animals (<2%). The 5'-triphosphate of CBV was a potent, selective inhibitor of HIV-1 RT, with Ki values for DNA polymerases (alpha, beta, gamma, and epsilon which were 90-, 2,900-, 1,200-, and 1,900-fold greater, respectively, than for RT (Ki, 21 nM). 1592U89 was relatively nontoxic to human bone marrow progenitors erythroid burst-forming unit and granulocyte-macrophage CFU (IC50s, 110 microM) and human leukemic and liver tumor cell lines. 1592U89 had excellent oral bioavailability (105% in the rat) and penetrated the CNS (rat brain and monkey cerebrospinal fluid) as well as AZT. Having demonstrated an excellent preclinical profile, 1592U89 has progressed to clinical evaluation in HIV-infected patients.

scholarly journals Ultra-strong bio-glue from genetically engineered polypeptides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chao Ma ◽  
Jing Sun ◽  
Bo Li ◽  
Yang Feng ◽  
Yao Sun ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Covalent Bond ◽  
Genetically Engineered ◽  
Supramolecular Interactions ◽  
Molar Ratio ◽  
High Adhesion ◽  
Strong Adhesion ◽  
Order Of Magnitude

AbstractThe development of biomedical glues is an important, yet challenging task as seemingly mutually exclusive properties need to be combined in one material, i.e. strong adhesion and adaption to remodeling processes in healing tissue. Here, we report a biocompatible and biodegradable protein-based adhesive with high adhesion strengths. The maximum strength reaches 16.5 ± 2.2 MPa on hard substrates, which is comparable to that of commercial cyanoacrylate superglue and higher than other protein-based adhesives by at least one order of magnitude. Moreover, the strong adhesion on soft tissues qualifies the adhesive as biomedical glue outperforming some commercial products. Robust mechanical properties are realized without covalent bond formation during the adhesion process. A complex consisting of cationic supercharged polypeptides and anionic aromatic surfactants with lysine to surfactant molar ratio of 1:0.9 is driven by multiple supramolecular interactions enabling such strong adhesion. We demonstrate the glue’s robust performance in vitro and in vivo for cosmetic and hemostasis applications and accelerated wound healing by comparison to surgical wound closures.

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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