Seema Kantak, Raffaella Faggioni, Allen G Cai, Maryam M Bhatti, Jing Li, Inna Vainshtein, Jackie Cheng, Brian A Mendelsohn, Jacques Gaudreault, Thi-Sau Migone, Jan-Willem Theunissen
{"title":"Preclinical characterization of XB002, an anti-tissue factor antibody-drug conjugate for the treatment of solid tumors.","authors":"Seema Kantak, Raffaella Faggioni, Allen G Cai, Maryam M Bhatti, Jing Li, Inna Vainshtein, Jackie Cheng, Brian A Mendelsohn, Jacques Gaudreault, Thi-Sau Migone, Jan-Willem Theunissen","doi":"10.1158/1535-7163.MCT-24-0002","DOIUrl":"https://doi.org/10.1158/1535-7163.MCT-24-0002","url":null,"abstract":"<p><p>Tissue factor (TF) is overexpressed in various cancers, where its expression is generally associated with poor disease outcomes. XB002 is an anti-TF antibody-drug conjugate designed to deliver a cytotoxic payload to TF-expressing tumors while minimizing adverse events related to disruption of TF function, notably bleeding. XB002 is composed of a zovodotin linker-payload conjugated to a monoclonal antibody (clone 25A3) that binds to TF with high affinity (KD = 0.86 nM). In vitro coagulation studies indicated that 25A3 did not interfere with the clotting cascade; at a 100 nM concentration, 25A3 had no effect on activation of coagulation factor X or thrombin generation. XB002 was internalized in TF-expressing cancer cell lines and displayed potent cytotoxic activity at sub-nanomolar concentrations. When evaluated in the HPAF-II xenograft model, XB002 (1.5 mg/kg, IV) given once weekly for 2 weeks induced complete regression with no tumor growth even at 5 weeks after the second dose. In murine patient-derived xenograft models, a single dose of XB002 (10 mg/kg, IV) inhibited tumor growth across multiple cancer models including bladder, cervical, gastric, head and neck squamous cell carcinoma (HNSCC), and non-small cell lung cancer. Further, complete tumor regression was observed in both the cervical and HNSCC models by 30 days post-treatment. In non-human primate models, XB002 showed exposure in the desired range and no evidence of bleeding or neutropenia. Taken together, these data demonstrate potential anti-tumor activity across a spectrum of oncology indications and strongly support its clinical development.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hae-June Lee, Changhwan Yoon, Benjamin Schmidt, Do Joong Park, Alexia Y Zhang, Hayriye V Erkizan, Jeffrey A Toretsky, David G Kirsch, Sam S Yoon
{"title":"Retraction: Combining PARP-1 Inhibition and Radiation in Ewing Sarcoma Results in Lethal DNA Damage.","authors":"Hae-June Lee, Changhwan Yoon, Benjamin Schmidt, Do Joong Park, Alexia Y Zhang, Hayriye V Erkizan, Jeffrey A Toretsky, David G Kirsch, Sam S Yoon","doi":"10.1158/1535-7163.MCT-24-0802","DOIUrl":"10.1158/1535-7163.MCT-24-0802","url":null,"abstract":"","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":"23 11","pages":"1680"},"PeriodicalIF":5.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11577241/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shengyan Xiang, Kendall C Craig, Xingju Luo, Darcy L Welch, Renan B Ferreira, Harshani R Lawrence, Nicholas J Lawrence, Damon R Reed, Mark G Alexandrow
{"title":"Identification of ATP-Competitive Human CMG Helicase Inhibitors for Cancer Intervention that Disrupt CMG-Replisome Function.","authors":"Shengyan Xiang, Kendall C Craig, Xingju Luo, Darcy L Welch, Renan B Ferreira, Harshani R Lawrence, Nicholas J Lawrence, Damon R Reed, Mark G Alexandrow","doi":"10.1158/1535-7163.MCT-23-0904","DOIUrl":"10.1158/1535-7163.MCT-23-0904","url":null,"abstract":"<p><p>The human CMG helicase (Cdc45-MCM-GINS) is a novel target for anticancer therapy. Tumor-specific weaknesses in the CMG are caused by oncogene-driven changes that adversely affect CMG function, and CMG activity is required for recovery from replicative stresses such as chemotherapy. Herein, we developed an orthogonal biochemical screening approach and identified CMG inhibitors (CMGi) that inhibit ATPase and helicase activities in an ATP-competitive manner at low micromolar concentrations. Structure-activity information, in silico docking, and testing with synthetic chemical compounds indicate that CMGi require specific chemical elements and occupy ATP-binding sites and channels within minichromosome maintenance (MCM) subunits leading to the ATP clefts, which are likely used for ATP/ADP ingress or egress. CMGi are therefore MCM complex inhibitors (MCMi). Biologic testing shows that CMGi/MCMi inhibit cell growth and DNA replication using multiple molecular mechanisms distinct from other chemotherapy agents. CMGi/MCMi block helicase assembly steps that require ATP binding/hydrolysis by the MCM complex, specifically MCM ring assembly on DNA and GINS recruitment to DNA-loaded MCM hexamers. During the S-phase, inhibition of MCM ATP binding/hydrolysis by CMGi/MCMi causes a \"reverse allosteric\" dissociation of Cdc45/GINS from the CMG that destabilizes replisome components Ctf4, Mcm10, and DNA polymerase-α, -δ, and -ε, resulting in DNA damage. CMGi/MCMi display selective toxicity toward multiple solid tumor cell types with K-Ras mutations, targeting the CMG and inducing DNA damage, Parp cleavage, and loss of viability. This new class of CMGi/MCMi provides a basis for small chemical development of CMG helicase-targeted anticancer compounds with distinct mechanisms of action.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":"1568-1585"},"PeriodicalIF":5.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11532780/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141563768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Weini Wang, Yanchi Zhou, Ji Wang, Shu Zhang, Ali Ozes, Hongyu Gao, Fang Fang, Yue Wang, Xiaona Chu, Yunlong Liu, Jun Wan, Anirban K Mitra, Heather M O'Hagan, Kenneth P Nephew
{"title":"Targeting Ovarian Cancer Stem Cells by Dual Inhibition of the Long Noncoding RNA HOTAIR and Lysine Methyltransferase EZH2.","authors":"Weini Wang, Yanchi Zhou, Ji Wang, Shu Zhang, Ali Ozes, Hongyu Gao, Fang Fang, Yue Wang, Xiaona Chu, Yunlong Liu, Jun Wan, Anirban K Mitra, Heather M O'Hagan, Kenneth P Nephew","doi":"10.1158/1535-7163.MCT-23-0314","DOIUrl":"10.1158/1535-7163.MCT-23-0314","url":null,"abstract":"<p><p>The persistence of cancer stem cells (CSC) is believed to contribute to resistance to platinum-based chemotherapy and disease relapse in ovarian cancer, the fifth leading cause of cancer-related death among US women. HOXC transcript antisense RNA (HOTAIR) is a long, noncoding RNA (lncRNA) overexpressed in high-grade serous ovarian cancer and linked to chemoresistance. However, HOTAIR impacts chromatin dynamics in ovarian CSCs. Oncogenic lncRNA's contributions to drug-resistant disease are incompletely understood. Here, we generated HOTAIR knockout (KO) high-grade serous ovarian cancer cell lines using paired CRISPR guide RNA design to investigate the function of HOTAIR. We show the loss of HOTAIR function resensitized ovarian cancer cells to platinum treatment and decreased the population of ovarian CSCs. Furthermore, HOTAIR KO inhibited the development of stemness-related phenotypes, including spheroid formation ability and expression of key stemness-associated genes ALDH1A1, NOTCH3, SOX9, and PROM1. HOTAIR KO altered the cellular transcriptome and chromatin accessibility landscape of multiple oncogenic-associated genes and pathways, including the NF-kB pathway. HOTAIR functions as an oncogene by recruiting enhancer of zeste homolog 2 (EZH2) to catalyze H3K27 trimethylation to suppress downstream tumor suppressor genes, and it was of interest to inhibit both HOTAIR and EZH2. In vivo, combining a HOTAIR inhibitor with an EZH2 inhibitor and platinum chemotherapy decreased tumor formation and increased survival. These results suggest a key role for HOTAIR in ovarian CSCs and malignant potential. Targeting HOTAIR in combination with epigenetic therapies may represent a therapeutic strategy to ameliorate ovarian cancer progression and resistance to platinum-based chemotherapy.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":"1666-1679"},"PeriodicalIF":5.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11534535/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141748633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Suna Erdem, Hyojae James Lee, Jayanth Surya Narayanan Shankara Narayanan, Mohottige Don Neranjan Tharuka, Jorge De la Torre, Tianchen Ren, Yixuan Kuang, Tharindumala Abeywardana, Kevin Li, Allison J Berger, Andrew M Lowy, Rebekah R White, Yuan Chen
{"title":"Inhibition of SUMOylation Induces Adaptive Antitumor Immunity against Pancreatic Cancer through Multiple Effects on the Tumor Microenvironment.","authors":"Suna Erdem, Hyojae James Lee, Jayanth Surya Narayanan Shankara Narayanan, Mohottige Don Neranjan Tharuka, Jorge De la Torre, Tianchen Ren, Yixuan Kuang, Tharindumala Abeywardana, Kevin Li, Allison J Berger, Andrew M Lowy, Rebekah R White, Yuan Chen","doi":"10.1158/1535-7163.MCT-23-0572","DOIUrl":"10.1158/1535-7163.MCT-23-0572","url":null,"abstract":"<p><p>Improvement of outcome in patients with pancreatic ductal adenocarcinoma (PDAC) requires exploration of novel therapeutic targets. Thus far, most studies of PDAC therapies, including those inhibiting small ubiquitin-like modifications (SUMOylation), have focused on PDAC epithelial cell biology, yet SUMOylation occurs in a variety of cell types. The mechanisms by which SUMOylation impacts PDAC in the context of its tumor microenvironment are poorly understood. We used clinically relevant orthotopic PDAC mouse models to investigate the effect of SUMOylation inhibition using a specific, clinical-stage compound, TAK-981. In contrast to its inhibition of PDAC cell proliferation in vitro, the survival benefit conferred by TAK-981 in vivo is dependent on the presence of T cells, suggesting that induction of adaptive antitumor immunity is an important antitumor effect of SUMOylation inhibition in vivo. To understand how this adaptive antitumor immunity is promoted, we investigated how SUMOylation inhibition in vivo alters major cell types/subtypes and their communications in the PDAC tumor microenvironment by performing transcriptomic analyses at single-cell resolution, which allowed mapping of cells in our orthotopic mouse model to cells in human PDAC tumors based on gene expression profiles. Findings are further validated by flow cytometry, immunofluorescence, IHC, western blots, and qPCR. The single-cell transcriptome dataset provided here suggests several combination strategies to augment adaptive immune responses that are necessary for durable disease control in patients with PDAC.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":"1597-1612"},"PeriodicalIF":5.3,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11534524/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141988385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yu-Chi Chen, Christopher G Bazewicz, Saketh S Dinavahi, Nicholas D Huntington, Todd D Schell, Gavin P Robertson
{"title":"Emerging Role of the p53 Pathway in Modulating Natural Killer Cell Mediated Immunity.","authors":"Yu-Chi Chen, Christopher G Bazewicz, Saketh S Dinavahi, Nicholas D Huntington, Todd D Schell, Gavin P Robertson","doi":"10.1158/1535-7163.MCT-24-0325","DOIUrl":"https://doi.org/10.1158/1535-7163.MCT-24-0325","url":null,"abstract":"<p><p>The p53 pathway plays an important role in role in cancer immunity. Mutation or downregulation of the proteins in the p53 pathway are prevalent in many cancers, contributing to tumor progression and immune dysregulation. Recent findings suggest that the activity of p53 within tumor cells, immune cells, and the tumor microenvironment can play an important role modulating natural killer (NK) cell-mediated immunity. Consequently, efforts to restore p53 pathway activity are being actively pursued to modulate this form of immunity. This review focuses on p53 activity regulating the infiltration and the activation of NK cells in the tumor immune microenvironment, which are illustrated in the Graphical Abstract for this review. Furthermore, impact of p53 and its regulation of NK cells on immunogenic cell death within solid tumors and the abscopal effect is reviewed. Finally, future avenues for therapeutically restoring p53 activity to improve NK cell-mediated anti-tumor immunity and optimize the effectiveness of cancer therapies are discussed.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142522466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matthew R Levengood, Christopher M Carosino, Xinqun Zhang, Sasha Lucas, David J Ortiz, Lori Westendorf, Alice P Chin, Arlan D Martin, Abbie Wong, Shawna M Hengel, Hao Sun, Weiping Zeng, Roma Yumul, Melissa Mc Dominguez, Yufei Chen, Janet H Zheng, Courtney A B Karlsson, Vivian H Trang, Peter D Senter, Shyra J Gardai
{"title":"Preclinical development of SGN-CD47M: Protease-activated antibody technology enables selective tumor targeting of the innate immune checkpoint receptor CD47.","authors":"Matthew R Levengood, Christopher M Carosino, Xinqun Zhang, Sasha Lucas, David J Ortiz, Lori Westendorf, Alice P Chin, Arlan D Martin, Abbie Wong, Shawna M Hengel, Hao Sun, Weiping Zeng, Roma Yumul, Melissa Mc Dominguez, Yufei Chen, Janet H Zheng, Courtney A B Karlsson, Vivian H Trang, Peter D Senter, Shyra J Gardai","doi":"10.1158/1535-7163.MCT-24-0371","DOIUrl":"https://doi.org/10.1158/1535-7163.MCT-24-0371","url":null,"abstract":"<p><p>CD47 is a cell surface glycoprotein that is expressed on normal human tissues and has a key role as a marker of self. Tumor cells have coopted CD47 overexpression to evade immune surveillance and thus blockade of CD47 is a highly active area of clinical exploration in oncology. However, clinical development of CD47-targeted agents has been complicated by its robust expression in normal tissues and the toxicities that arise from blocking this inhibitory signal. Further, pro-phagocytic signals are not uniformly expressed in tumors and antibody blockade alone is often not sufficient to drive antitumor activity. The inclusion of an IgG1 antibody backbone into therapeutic design has been shown to serve as an additional pro-phagocytic signal but also exacerbates toxicities in normal tissues. Therefore, a need persists for more selective therapeutic modalities targeting CD47. To address these challenges, we developed SGN-CD47M, a humanized anti-CD47 IgG1 monoclonal antibody linked to novel masking peptides through linkers designed to be cleaved by active proteases enriched in the tumor microenvironment. Masking technology has the potential to increase the amount of drug that reaches the tumor microenvironment, while concomitantly reducing systemic toxicities. We demonstrate that SGN-CD47M is well tolerated in cynomolgus monkeys and displays a 20-fold improvement in tolerability to hematologic toxicities when compared to the unmasked antibody. SGN-CD47M also displays preferential activation in the tumor microenvironment that leads to robust single-agent antitumor activity. For these reasons, SGN-CD47M may have enhanced antitumor activity and improved tolerability relative to existing therapies that target the CD47-SIRPα interaction.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Potential mechanisms of interstitial lung disease induced by antibody-drug conjugates based on quantitative analysis of drug distribution.","authors":"Shigehiro Koganemaru, Hirobumi Fuchigami, Chihiro Morizono, Hiroko Shinohara, Yasutoshi Kuboki, Keiji Fruuchi, Toshimitsu Uenaka, Toshihiko Doi, Masahiro Yasunaga","doi":"10.1158/1535-7163.MCT-24-0267","DOIUrl":"https://doi.org/10.1158/1535-7163.MCT-24-0267","url":null,"abstract":"<p><p>Antibody-drug conjugates (ADCs) are a rapidly advancing category of therapeutic agents with notable anti-cancer efficacy. However, the emergence of interstitial lung disease (ILD) as a severe ADC-associated adverse event highlights the need to better understand the underlying mechanisms. In this study, xenograft model mice with tumors expressing different levels of the trophoblast antigen 2 (TROP2) were generated by subcutaneously transplanting the various TROP2-expression cancer lines. The mice received different doses of TROP2-eribulin, a novel TROP2-targeting ADC, composed of an anti-TROP2 antibody and the eribulin payload, joined by a cleavable linker. The concentration and distribution of TROP2-eribulin, as well as the pharmacokinetics of eribulin release, were assessed in tumor and lung tissues. Analysis of tumor tissue showed that the concentration of released eribulin was approximately 10-fold higher in NCI-H2110 (high TROP2 expression) than in A549 (low TROP2 expression), while analysis of lung tissue showed that TROP2-eribulin was distributed in lung tissue in a dose-dependent manner of TROP2-eribulin regardless of TROP2 expression, with significantly more eribulin released in the high-dose group than in the other dose groups (P < 0.05). Immunofluorescence assay analysis showed that TROP2-eribuilin localized to alveolar macrophages. In the analysis using human- leukemia monocytic cell, the concentration of eribulin released from TROP2-eribuilin was significantly reduced by the use of an Fc receptor inhibitor (P < 0.05). These results revealed that Fcγ-receptor-mediated uptake by alveolar macrophages releases cytotoxic payload into lung tissue, helping to clarify the pathogenesis of ADC-induced ILD.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sonja Dragojevic, Emily J Smith, Michael S Regan, Sylwia A Stopka, Gerard Baquer, Zhiyi Xue, Wenjuan Zhang, Margaret A Connors, Jake A Kloeber, Zeng Hu, Katrina K Bakken, Lauren L Ott, Brett L Carlson, Danielle M Burgenske, Paul A Decker, Shulan Tian, Shiv K Gupta, Daniel J Laverty, Jeanette E Eckel-Passow, William F Elmquist, Nathalie Y R Agar, Zachary D Nagel, Jann N Sarkaria, Cameron M Callaghan
{"title":"DNA-PK inhibition shows differential radiosensitization in orthotopic GBM PDX models based on DDR pathway deficits.","authors":"Sonja Dragojevic, Emily J Smith, Michael S Regan, Sylwia A Stopka, Gerard Baquer, Zhiyi Xue, Wenjuan Zhang, Margaret A Connors, Jake A Kloeber, Zeng Hu, Katrina K Bakken, Lauren L Ott, Brett L Carlson, Danielle M Burgenske, Paul A Decker, Shulan Tian, Shiv K Gupta, Daniel J Laverty, Jeanette E Eckel-Passow, William F Elmquist, Nathalie Y R Agar, Zachary D Nagel, Jann N Sarkaria, Cameron M Callaghan","doi":"10.1158/1535-7163.MCT-24-0003","DOIUrl":"10.1158/1535-7163.MCT-24-0003","url":null,"abstract":"<p><p>Glioblastoma (GBM) remains one of the most therapy-resistant malignancies with frequent local failures despite aggressive surgery, chemotherapy, and ionizing radiation (IR). Small molecule inhibitors of DNA-dependent protein kinase (DNA-PKi's) are potent radiosensitizers currently in clinical trials. Determining which patients may benefit from radiosensitization with DNA-PKi's is critical to avoid unnecessary increased risk of normal tissue toxicity. In this study we used GBM patient derived xenografts (PDXs) in orthotopic murine models to study the relationship between molecular features, pharmacokinetics, and the radiosensitizing potential of the DNA-PKi peposertib. We show that peposertib radiosensitizes established and PDX GBM lines in vitro at 300nM and above, with significant increase in radiosensitization by maintaining post-IR exposure for >12 hours. Radiosensitization by peposertib is mediated by catalytic inhibition of DNA-PK, and knock-down of DNA-PK by short hairpin RNA (shRNA) largely abolished the radiosensitizing effect. Peposertib decreased auto-phosphorylation of DNA-PKcs after IR in a dose-dependent manner with delay in resolution of γH2AX foci at 24 hours. The addition of peposertib to IR significantly increased survival in GBM120 orthotopic xenografts, but not in GBM10. There was no difference in plasma or average tumor concentrations of peposertib in the two cohorts. While the mechanism underpinning this discordant effect in vitro vs. in vivo is not clear, there was an association for greater sensitization in TP53 mutant lines. Transfection of a dominant-negative TP53 mutant in baseline TP53 wildtype GBM lines significantly delayed growth and decreased NHEJ efficiency (but not Homologous Recombination), after peposertib exposure.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142504276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ahmad Joshkon, Wael Traboulsi, Magali Terme, Richard Bachelier, Hussein Fayyad-Kazan, Françoise Dignat-George, Alexandrine Foucault-Bertaud, Aurelie S Leroyer, Nathalie Bardin, Marcel Blot-Chabaud
{"title":"Soluble CD146 cooperates with VEGF-A to generate an immunosuppressive microenvironment in CD146-positive tumors: interest of a combined antibody-based therapy.","authors":"Ahmad Joshkon, Wael Traboulsi, Magali Terme, Richard Bachelier, Hussein Fayyad-Kazan, Françoise Dignat-George, Alexandrine Foucault-Bertaud, Aurelie S Leroyer, Nathalie Bardin, Marcel Blot-Chabaud","doi":"10.1158/1535-7163.MCT-24-0008","DOIUrl":"https://doi.org/10.1158/1535-7163.MCT-24-0008","url":null,"abstract":"<p><p>Tumor development necessitates immune escape through different mechanisms. To counteract these effects, the development of therapies targeting Immune Checkpoints (ICP) has generated interest as they have produced lasting objective responses in patients with advanced metastatic tumors. However, many tumors do not respond to inhibitors of ICP, necessitating to further study the underlying mechanisms of exhaustion. Vascular Endothelial Growth Factor a (VEGFa), a pro-angiogenic molecule secreted by tumors, was described to participate to tumor immune exhaustion by increasing ICP, justifying in part the use of an anti-VEGFa monoclonal antibody (mAb), bevacizumab, in patients. However, recent studies from our group have demonstrated that tumors can escape anti-VEGFa therapy through the secretion of soluble CD146 (sCD146). In this study, we show that both VEGFa and sCD146 cooperate to create an immunosuppressive microenvironment by increasing the expression of ICP. In addition, sCD146 favors pro-tumoral M2-type macrophages and induces the secretion of pro-inflammatory cytokines. An anti-sCD146 mAb reverses these effects and displays additive effects with anti-VEGFa antibody to eliminate tumors in a syngeneic murine model grafted with melanoma cells. Combining bevacizumab with mucizumab could thus be of major therapeutic interest to prevent immune escape in malignant melanoma and other CD146-positive tumors.</p>","PeriodicalId":18791,"journal":{"name":"Molecular Cancer Therapeutics","volume":" ","pages":""},"PeriodicalIF":5.3,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142470224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}