bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from TGFβ Blockade Enhances Radiotherapy Abscopal Efficacy Effects in Combination with Anti-PD1 and Anti-CD137 Immunostimulatory Monoclonal Antibodies
Authors: Rodríguez-Ruiz María E. , Rodríguez Inmaculada , Mayorga Lina , Labiano Tania , Barbes Benigno , Etxeberria Iñaki , Ponz-Sarvise Mariano , Azpilikueta Arantza , Bolaños Elixabet , Sanmamed Miguel F. , Berraondo Pedro , Calvo Felipe A. , Barcelos-Hoff Mary Helen , Perez-Gracia Jose L. , Melero Ignacio
Published: April 2023

Abstract
Radiotherapy can be synergistically combined with immunotherapy in mouse models, extending its efficacious effects outside of the irradiated field (abscopal effects). We previously reported that a regimen encompassing local radiotherapy in combination with anti-CD137 plus anti–PD-1 mAbs achieves potent abscopal effects against syngeneic transplanted murine tumors up to a certain tumor size. Knowing that TGFβ expression or activation increases in irradiated tissues, we tested whether TGFβ blockade may further enhance abscopal effects in conjunction with the anti–PD-1 plus anti-CD137 mAb combination. Indeed, TGFβ blockade with 1D11, a TGFβ-neutralizing mAb, markedly enhanced abscopal effects and overall treatment efficacy against subcutaneous tumors of either 4T1 breast cancer cells or large MC38 colorectal tumors. Increases in CD8 T cells infiltrating the nonirradiated lesion were documented upon combined treatment, which intensely expressed Granzyme-B as an indicator of cytotoxic effector capability. Interestingly, tumor tissue but not healthy tissue irradiation results in the presence of higher concentrations of TGFβ in the nonirradiated contralateral tumor that showed smad2/3 phosphorylation increases in infiltrating CD8 T cells. In conclusion, radiotherapy-induced TGFβ hampers abscopal efficacy even upon combination with a potent immunotherapy regimen. Therefore, TGFβ blockade in combination with radioimmunotherapy results in greater efficacy.
Data from Lenalidomide Augments the Antitumor Activities of Eps8 Peptide-Specific Cytotoxic T Lymphocytes against Multiple Myeloma
Authors: Xie Xiaoling , Chen Yiran , Hu Yuxing , He Yanjie , Zhang Honghao , Li Yuhua
Published: April 2023

Abstract
Cancer immunotherapy is a promising new approach to cancer treatment. It has been demonstrated that a high number of tumor-specific cytotoxic T cells (CTL) is associated with increased survival in patients with multiple myeloma. Here, we focused on EGFR pathway substrate 8 (Eps8) as a candidate tumor-associated antigen (TAA) in multiple myeloma. Previous work has shown that Eps8-based immunotherapy in HLA-A2+ cancer patients may result in efficient antitumor immune responses against diverse tumor types. To improve immunotherapy for patients with multiple myeloma, we constructed a cocktail vaccine by combining several HLA-A2–restricted epitopes derived from Eps8 (Eps8cocktail), including Eps8101-2L (WLQDMILQV), Eps8276-1Y9V (YLDDIEFFV), and Eps8455-1Y (YLAESVANV). The CTLs induced by Eps8cocktail (Eps8cocktail-CTLs) showed highly effective anti–multiple myeloma activity, including Th1 cytokines production, cell proliferation, and cytotoxicity against HLA-A2+ multiple myeloma cells. This study highlights the importance of using a cocktail vaccine instead of a single-peptide vaccine to induce a robust response. Importantly, we revealed that lenalidomide effectively stimulated the antitumor activity of the Eps8cocktail-CTLs, with increasing expression trends for T-cell markers (CD28, CD40L, 41BB, and OX40). Compared with unstimulated CTLs and Eps8cocktail-CTLs, lenalidomide-treated Eps8cocktail-CTLs showed superior anti–multiple myeloma activity in humanized multiple myeloma models, including delaying tumor burden increases due to enhanced immune function. These results provide the framework for an Eps8 cocktail vaccination therapy to induce effective Eps8-specific CTLs in HLA-A2+ patients with multiple myeloma. Moreover, these studies further demonstrate that lenalidomide augments the immune response, providing a possibility for its use in combination with peptide vaccines to improve patient outcomes.
Data from Targeting the MET Receptor Tyrosine Kinase as a Strategy for Radiosensitization in Locoregionally Advanced Head and Neck Squamous Cell Carcinoma
Authors: Nisa Lluís , Francica Paola , Giger Roland , Medo Matúš , Elicin Olgun , Friese-Hamim Manja , Wilm Claudia , Stroh Christopher , Bojaxhiu Beat , Quintin Aurélie , Caversaccio Marco D. , Dettmer Matthias S. , Buchwalder Mélanie , Brodie Tess M. , Aebersold Daniel M. , Zimmer Yitzhak , Carey Thomas E. , Medová Michaela
Published: April 2023

Abstract
Radiotherapy (RT) along with surgery is the mainstay of treatment in head and neck squamous cell carcinoma (HNSCC). Radioresistance represents a major source of treatment failure, underlining the urgent necessity to explore and implement effective radiosensitization strategies. The MET receptor widely participates in the acquisition and maintenance of an aggressive phenotype in HNSCC and modulates the DNA damage response following ionizing radiation (IR). Here, we assessed MET expression and mutation status in primary and metastatic lesions within a cohort of patients with advanced HNSCC. Moreover, we investigated the radiosensitization potential of the MET inhibitor tepotinib in a panel of cell lines, in vitro and in vivo, as well as in ex vivo patient-derived organotypic tissue cultures (OTC). MET was highly expressed in 62.4% of primary tumors and in 53.6% of lymph node metastases (LNM), and in 6 of 9 evaluated cell lines. MET expression in primaries and LNMs was significantly associated with decreased disease control in univariate survival analyses. Tepotinib abrogated MET phosphorylation and to distinct extent MET downstream signaling. Pretreatment with tepotinib resulted in variable radiosensitization, enhanced DNA damage, cell death, and G2–M-phase arrest. Combination of tepotinib with IR led to significant radiosensitization in one of two tested in vivo models. OTCs revealed differential patterns of response toward tepotinib, irradiation, and combination of both modalities. The molecular basis of tepotinib-mediated radiosensitization was studied by a CyTOF-based single-cell mass cytometry approach, which uncovered that MET inhibition modulated PI3K activity in cells radiosensitized by tepotinib but not in the resistant ones.
Data from ERK Inhibitor LY3214996 Targets ERK Pathway–Driven Cancers: A Therapeutic Approach Toward Precision Medicine
Authors: Bhagwat Shripad V. , McMillen William T. , Cai Shufen , Zhao Baohui , Whitesell Matthew , Shen Weihua , Kindler Lisa , Flack Robert S. , Wu Wenjuan , Anderson Bryan , Zhai Yan , Yuan Xiu-Juan , Pogue Meghann , Van Horn Robert D. , Rao Xi , McCann Denis , Dropsey Andrew J. , Manro Jason , Walgren Jennie , Yuen Eunice , Rodriguez Michael J. , Plowman Gregory D. , Tiu Ramon V. , Joseph Sajan , Peng Sheng-Bin
Published: April 2023

Abstract
The ERK pathway is critical in oncogenesis; aberrations in components of this pathway are common in approximately 30% of human cancers. ERK1/2 (ERK) regulates cell proliferation, differentiation, and survival and is the terminal node of the pathway. BRAF- and MEK-targeted therapies are effective in BRAF V600E/K metastatic melanoma and lung cancers; however, responses are short-lived due to emergence of resistance. Reactivation of ERK signaling is central to the mechanisms of acquired resistance. Therefore, ERK inhibition provides an opportunity to overcome resistance and leads to improved efficacy. In addition, KRAS-mutant cancers remain an unmet medical need in which ERK inhibitors may provide treatment options alone or in combination with other agents. Here, we report identification and activity of LY3214996, a potent, selective, ATP-competitive ERK inhibitor. LY3214996 treatment inhibited the pharmacodynamic biomarker, phospho-p90RSK1, in cells and tumors, and correlated with LY3214996 exposures and antitumor activities. In in vitro cell proliferation assays, sensitivity to LY3214996 correlated with ERK pathway aberrations. LY3214996 showed dose-dependent tumor growth inhibition and regression in xenograft models harboring ERK pathway alterations. Importantly, more than 50% target inhibition for up to 8 to 16 hours was sufficient for significant tumor growth inhibition as single agent in BRAF- and KRAS-mutant models. LY3214996 also exhibited synergistic combination benefit with a pan-RAF inhibitor in a KRAS-mutant colorectal cancer xenograft model. Furthermore, LY3214996 demonstrated antitumor activity in BRAF-mutant models with acquired resistance in vitro and in vivo. Based on these preclinical data, LY3214996 has advanced to an ongoing phase I clinical trial (NCT02857270).
Data from Sphingosine Kinase-1 Protects Multiple Myeloma from Apoptosis Driven by Cancer-Specific Inhibition of RTKs
Authors: Tsukamoto Shuntaro , Huang Yuhui , Kumazoe Motofumi , Lesnick Connie , Yamada Shuhei , Ueda Naoki , Suzuki Takashi , Yamashita Shuya , Kim Yoon Hee , Fujimura Yoshinori , Miura Daisuke , Kay Neil E. , Shanafelt Tait D. , Tachibana Hirofumi
Published: April 2023

Abstract
Activation of acid sphingomyelinase (ASM) leads to ceramide accumulation and induces apoptotic cell death in cancer cells. In the present study, we demonstrate that the activation of ASM by targeting cancer-overexpressed 67-kDa laminin receptors (67LR) induces lipid raft disruption and inhibits receptor tyrosine kinase (RTK) activation in multiple myeloma cells. Sphingosine kinase 1 (SphK1), a negative regulator of ceramide accumulation with antiapoptotic effects, was markedly elevated in multiple myeloma cells. The silencing of SphK1 potentiated the apoptotic effects of the green tea polyphenol epigallocatechin-3-O-gallate (EGCG), an activator of ASM through 67LR. Furthermore, the SphK1 inhibitor safingol synergistically sensitized EGCG-induced proapoptotic cell death and tumor suppression in multiple myeloma cells by promoting the prevention of RTK phosphorylation and activation of death-associated protein kinase 1 (DAPK1). We propose that targeting 67LR/ASM and SphK1 may represent a novel therapeutic strategy against multiple myeloma. Mol Cancer Ther; 14(10); 2303–12. ©2015 AACR.
Data from Anti-KIT Monoclonal Antibody Treatment Enhances the Antitumor Activity of Immune Checkpoint Inhibitors by Reversing Tumor-Induced Immunosuppression
Authors: Garton Andrew J. , Seibel Scott , Lopresti-Morrow Lori , Crew Linda , Janson Neal , Mandiyan Sreekala , Trombetta E. Sergio , Pankratz Shannon , LaVallee Theresa M. , Gedrich Richard
Published: April 2023

Abstract
The receptor tyrosine kinase KIT is an established oncogenic driver of tumor growth in certain tumor types, including gastrointestinal stromal tumors, in which constitutively active mutant forms of KIT represent an actionable target for small-molecule tyrosine kinase inhibitors. There is also considerable potential for KIT to influence tumor growth indirectly based on its expression and function in cell types of the innate immune system, most notably mast cells. We have evaluated syngeneic mouse tumor models for antitumor effects of an inhibitory KIT mAb, dosed either alone or in combination with immune checkpoint inhibitors. Anti-KIT mAb treatment enhanced the antitumor activity of anti–CTLA-4 and anti–PD-1 mAbs, and promoted immune responses by selectively reducing the immunosuppressive monocytic myeloid-derived suppressor cell population and by restoring CD8+ and CD4+ T-cell populations to levels observed in naïve mice. These data provide a rationale for clinical investigation of the human KIT-specific mAb KTN0158 in novel immuno-oncology combinations with immune checkpoint inhibitors and other immunotherapeutic agents across a range of tumor types. Mol Cancer Ther; 16(4); 671–80. ©2017 AACR.
Data from AKT Inhibition Modulates H3K4 Demethylase Levels in PTEN-Null Prostate Cancer
Authors: Khan Mohammad Imran , Hamid Abid , Rath Suvasmita , Ateeq Bushra , Khan Qateeb , Siddiqui Imtiaz A. , Adhami Vaqar Mustafa , Choudhry Hani , Zamzami Mazin A. , Mukhtar Hasan
Published: April 2023

Abstract
Hyperactivated AKT kinase due to loss of its negative regulator PTEN influences many aspects of cancer biology, including chromatin. AKT primarily regulates acetyl-CoA production and phosphorylates many histone-modulating enzymes, resulting in their activation or inhibition. Therefore, understanding the therapeutic impact of AKT inhibition on chromatin-related events is essential. Here, we report that AKT inhibition in prostate-specific PTEN knockout mice significantly induces di- and trimethylation of H3K4 with concomitant reduction in H3K9 acetylation. Mechanistically, we observed that AKT inhibition reduces expression of the H3K4 methylation-specific histone demethylases KDM5 family, especially KDM5B expression at transcriptional levels. Furthermore, we observed that AKT negatively regulates miR-137 levels, which transcriptionally represses KDM5B expression. Overexpression of miR-137 significantly reduced KDM5B and increased H3K4 methylation levels but failed to change AKT phosphorylation. Overall, we observed that AKT transcriptionally regulates KDM5B mainly via repression of miR-137. Our data identify a mechanism by which AKT kinase modulates the prostate cancer epigenome through regulating H3K4 methylation. Additional studies on AKT inhibition–mediated induction of H3K4 methylation will help in designing strategies to enhance the therapeutic efficacy of PI3K/AKT inhibitors.
Data from The Selective Tie2 Inhibitor Rebastinib Blocks Recruitment and Function of Tie2Hi Macrophages in Breast Cancer and Pancreatic Neuroendocrine Tumors
Authors: Harney Allison S. , Karagiannis George S. , Pignatelli Jeanine , Smith Bryan D. , Kadioglu Ece , Wise Scott C. , Hood Molly M. , Kaufman Michael D. , Leary Cynthia B. , Lu Wei-Ping , Al-Ani Gada , Chen Xiaoming , Entenberg David , Oktay Maja H. , Wang Yarong , Chun Lawrence , De Palma Michele , Jones Joan G. , Flynn Daniel L. , Condeelis John S.
Published: April 2023

Abstract
Tumor-infiltrating myeloid cells promote tumor progression by mediating angiogenesis, tumor cell intravasation, and metastasis, which can offset the effects of chemotherapy, radiation, and antiangiogenic therapy. Here, we show that the kinase switch control inhibitor rebastinib inhibits Tie2, a tyrosine kinase receptor expressed on endothelial cells and protumoral Tie2-expressing macrophages in mouse models of metastatic cancer. Rebastinib reduces tumor growth and metastasis in an orthotopic mouse model of metastatic mammary carcinoma through reduction of Tie2+ myeloid cell infiltration, antiangiogenic effects, and blockade of tumor cell intravasation mediated by perivascular Tie2Hi/Vegf-AHi macrophages in the tumor microenvironment of metastasis (TMEM). The antitumor effects of rebastinib enhance the efficacy of microtubule inhibiting chemotherapeutic agents, either eribulin or paclitaxel, by reducing tumor volume, metastasis, and improving overall survival. Rebastinib inhibition of angiopoietin/Tie2 signaling impairs multiple pathways in tumor progression mediated by protumoral Tie2+ macrophages, including TMEM-dependent dissemination and angiopoietin/Tie2-dependent angiogenesis. Rebastinib is a promising therapy for achieving Tie2 inhibition in cancer patients. Mol Cancer Ther; 16(11); 2486–501. ©2017 AACR.
Data from Synthetic Lethal Targeting of ARID1A-Mutant Ovarian Clear Cell Tumors with Dasatinib
Authors: Miller Rowan E. , Brough Rachel , Bajrami Ilirjana , Williamson Chris T. , McDade Simon , Campbell James , Kigozi Asha , Rafiq Rumana , Pemberton Helen , Natrajan Rachel , Joel Josephine , Astley Holly , Mahoney Claire , Moore Jonathan D. , Torrance Chris , Gordan John D. , Webber James T. , Levin Rebecca S. , Shokat Kevan M. , Bandyopadhyay Sourav , Lord Christopher J. , Ashworth Alan
Published: April 2023

Abstract
New targeted approaches to ovarian clear cell carcinomas (OCCC) are needed, given the limited treatment options in this disease and the poor response to standard chemotherapy. Using a series of high-throughput cell-based drug screens in OCCC tumor cell models, we have identified a synthetic lethal (SL) interaction between the kinase inhibitor dasatinib and a key driver in OCCC, ARID1A mutation. Imposing ARID1A deficiency upon a variety of human or mouse cells induced dasatinib sensitivity, both in vitro and in vivo, suggesting that this is a robust synthetic lethal interaction. The sensitivity of ARID1A-deficient cells to dasatinib was associated with G1–S cell-cycle arrest and was dependent upon both p21 and Rb. Using focused siRNA screens and kinase profiling, we showed that ARID1A-mutant OCCC tumor cells are addicted to the dasatinib target YES1. This suggests that dasatinib merits investigation for the treatment of patients with ARID1A-mutant OCCC. Mol Cancer Ther; 15(7); 1472–84. ©2016 AACR.
Data from The Bromodomain BET Inhibitor JQ1 Suppresses Tumor Angiogenesis in Models of Childhood Sarcoma
Authors: Bid Hemant K. , Phelps Doris A. , Xaio Linlin , Guttridge Denis C. , Lin Jiayuh , London Cheryl , Baker Laurence H. , Mo Xiaokui , Houghton Peter J.
Published: April 2023

Abstract
The bromodomain and extra-terminal domain inhibitor JQ1 has marked antitumor activity against several hematologic malignancies as well as solid tumor models. Here, we investigated its activity in vitro and in vivo against models of childhood rhabdomyosarcoma and Ewing sarcoma. In vitro, JQ1 (but not the inactive enantiomer JQ1R) inhibited cell proliferation and increased G1 fraction of cells, although there was no correlation between cell line sensitivity and suppression of c-MYC or MYCN. In vivo, xenografts showed significant inhibition of growth during the period of treatment, and rapid regrowth after treatment was stopped, activity typical of antiangiogenic agents. Furthermore, xenografts derived from cell lines intrinsically resistant or sensitive to JQ1 in vitro had similar sensitivity in vivo as xenografts. Further investigation showed that JQ1 reduced tumor vascularization. This was secondary to both drug-induced downregulation of tumor-derived growth factors and direct effects of JQ1 on vascular elements. JQ1 suppressed VEGF-stimulated vascularization of Matrigel plugs in mice, and in vitro suppressed differentiation, proliferation, and invasion of human umbilical cord vascular endothelial cells (HUVEC). In HUVECs, JQ1 partially suppressed c-MYC levels, but dramatically reduced AP-1 levels and activity through suppression of the AP-1–associated protein FOSL1. Our data suggest that the antitumor activity of JQ1 in these sarcoma models is largely a consequence of its antiangiogenic activity. Mol Cancer Ther; 15(5); 1018–28. ©2016 AACR.
Data from Optimization of RAS/BRAF Mutational Analysis Confirms Improvement in Patient Selection for Clinical Benefit to Anti-EGFR Treatment in Metastatic Colorectal Cancer
Authors: Santos Cristina , Azuara Daniel , Garcia-Carbonero Rocio , Alfonso Pilar Garcia , Carrato Alfredo , Elez Mª Elena , Gomez Auxiliadora , Losa Ferran , Montagut Clara , Massuti Bartomeu , Navarro Valenti , Varela Mar , Lopez-Doriga Adriana , Moreno Victor , Valladares Manuel , Manzano Jose Luis , Vieitez Jose Maria , Aranda Enrique , Sanjuan Xavier , Tabernero Josep , Capella Gabriel , Salazar Ramon
Published: April 2023

Abstract
In metastatic colorectal cancer (mCRC), recent studies have shown the importance to accurately quantify low-abundance mutations of the RAS pathway because anti-EGFR therapy may depend on certain mutation thresholds. We aimed to evaluate the added predictive value of an extended RAS panel testing using two commercial assays and a highly sensitive and quantitative digital PCR (dPCR). Tumor samples from 583 mCRC patients treated with anti–EGFR- (n = 255) or bevacizumab- (n = 328) based therapies from several clinical trials and retrospective series from the TTD/RTICC Spanish network were analyzed by cobas, therascreen, and dPCR. We evaluated concordance between techniques using the Cohen kappa index. Response rate, progression-free survival (PFS), and overall survival (OS) were correlated to the mutational status and the mutant allele fraction (MAF). Concordance between techniques was high when analyzing RAS and BRAF (Cohen kappa index around 0.75). We observed an inverse correlation between MAF and response in the anti-EGFR cohort (P < 0.001). Likelihood ratio analysis showed that a fraction of 1% or higher of any mutated alleles offered the best predictive value. PFS and OS were significantly longer in RAS/BRAF wild-type patients, independently of the technique. However, the predictability of both PFS and OS were higher when we considered a threshold of 1% in the RAS scenario (HR = 1.53; CI 95%, 1.12–2.09 for PFS, and HR = 1.9; CI 95%, 1.33–2.72 for OS). Although the rate of mutations observed among techniques is different, RAS and BRAF mutational analysis improved prediction of response to anti-EGFR therapy. Additionally, dPCR with a threshold of 1% outperformed the other platforms. Mol Cancer Ther; 16(9); 1999–2007. ©2017 AACR.
Data from A Prodrug of Two Approved Drugs, Cisplatin and Chlorambucil, for Chemo War Against Cancer
Authors: Pathak Rakesh K. , Wen Ru , Kolishetti Nagesh , Dhar Shanta
Published: April 2023

Abstract
Cancer cells maintain normal mitochondrial glutathione as one of the defense mechanisms to inhibit mitochondrial membrane polarization and hence apoptosis. A combinational therapeutic modality Platin-Cbl, a prodrug of FDA-approved chemotherapeutic agents, cisplatin and chlorambucil (Cbl), was synthesized and characterized to explore the potential of this compound to initiate chemo war on cancer cells using the active drugs, cisplatin and Cbl, when delivered to the cellular power house mitochondrion using a targeted nanoparticle designed to get associated with this organelle. Platin-Cbl demonstrated significantly high cytotoxic activity across a number of tumor cell lines as well as in a cisplatin-resistant cancer cell line compared with cisplatin or its mixture with Cbl suggesting its unique potency in cisplatin-resistant tumors. A mitochondria-targeted nanoparticle formulation of Platin-Cbl allowed for its efficacious mitochondrial delivery. In vitro studies documented high potency of Platin-Cbl nanoparticle formulations. Cisplatin-resistant cells upon treatment with Platin-Cbl were still able to manage energy production to a certain extent via fatty acid pathway; the advantage of using T-Platin-Cbl-NP is that this nanoparticle treatment causes impairment of all metabolic pathways in cisplatin-resistant cells forcing the cells to undergo efficient apoptosis. This study highlights a combination of several beneficial effects for a cascade of events to overcome resistance associated with single drug therapy. Mol Cancer Ther; 16(4); 625–36. ©2017 AACR.
Data from Reactivation of the p90RSK–CDC25C Pathway Leads to Bypass of the Ganetespib-Induced G2–M Arrest and Mediates Acquired Resistance to Ganetespib in KRAS-Mutant NSCLC
Authors: Chatterjee Suman , Huang Eric H.-B. , Christie Ian , Burns Timothy F.
Published: April 2023

Abstract
A subset of non–small cell lung cancers (NSCLC) are dependent upon oncogenic driver mutations, including the most frequently observed driver mutant KRAS, which is associated with a poor prognosis. As direct RAS targeting in the clinic has been unsuccessful to date, use of Hsp90 inhibitors appeared to be a promising therapy for KRAS-mutant NSCLC; however, limited clinical efficacy was observed due to rapid resistance. Furthermore, the combination of the Hsp90 inhibitor (Hsp90i), ganetespib, and docetaxel was tested in a phase III clinical trial and failed to demonstrate benefit. Here, we investigated the mechanism(s) of resistance to ganetespib and explored why the combination with docetaxel failed in the clinic. We have not only identified a critical role for the bypass of the G2–M cell-cycle checkpoint as a mechanism of ganetespib resistance (GR) but have also found that GR leads to cross-resistance to docetaxel. Reactivation of p90RSK and its downstream target, CDC25C, was critical for GR and mediated the bypass of a G2–M arrest. Overexpression of either p90RSK or CDC25C lead to bypass of G2–M arrest and induced ganetespib resistance in vitro and in vivo. Moreover, resistance was dependent on p90RSK/CDC25C signaling, as synthetic lethality to ERK1/2, p90RSK, or CDC25C inhibitors was observed. Importantly, the combination of ganetespib and p90RSK or CDC25C inhibitors was highly efficacious in parental cells. These studies provide a way forward for Hsp90 inhibitors through the development of novel rationally designed Hsp90 inhibitor combinations that may prevent or overcome resistance to Hsp90i. Mol Cancer Ther; 16(8); 1658–68. ©2017 AACR.
Data from APC Mutations as a Potential Biomarker for Sensitivity to Tankyrase Inhibitors in Colorectal Cancer
Authors: Tanaka Noritaka , Mashima Tetsuo , Mizutani Anna , Sato Ayana , Aoyama Aki , Gong Bo , Yoshida Haruka , Muramatsu Yukiko , Nakata Kento , Matsuura Masaaki , Katayama Ryohei , Nagayama Satoshi , Fujita Naoya , Sugimoto Yoshikazu , Seimiya Hiroyuki
Published: April 2023

Abstract
In most colorectal cancers, Wnt/β-catenin signaling is activated by loss-of-function mutations in the adenomatous polyposis coli (APC) gene and plays a critical role in tumorigenesis. Tankyrases poly(ADP-ribosyl)ate and destabilize Axins, a negative regulator of β-catenin, and upregulate β-catenin signaling. Tankyrase inhibitors downregulate β-catenin and are expected to be promising therapeutics for colorectal cancer. However, colorectal cancer cells are not always sensitive to tankyrase inhibitors, and predictive biomarkers for the drug sensitivity remain elusive. Here we demonstrate that the short-form APC mutations predict the sensitivity of colorectal cancer cells to tankyrase inhibitors. By using well-established colorectal cancer cell lines, we found that tankyrase inhibitors downregulated β-catenin in the drug-sensitive, but not resistant, colorectal cancer cells. The drug-sensitive cells showed higher Tcf/LEF transcriptional activity than the resistant cells and possessed “short” truncated APCs lacking all seven β-catenin-binding 20-amino acid repeats (20-AARs). In contrast, the drug-resistant cells possessed “long” APC retaining two or more 20-AARs. Knockdown of the long APCs with two 20-AARs increased β-catenin, Tcf/LEF transcriptional activity and its target gene AXIN2 expression. Under these conditions, tankyrase inhibitors were able to downregulate β-catenin in the resistant cells. These results indicate that the long APCs are hypomorphic mutants, whereas they exert a dominant-negative effect on Axin-dependent β-catenin degradation caused by tankyrase inhibitors. Finally, we established 16 patient-derived colorectal cancer cells and confirmed that the tankyrase inhibitor–responsive cells harbor the short-form APC mutations. These observations exemplify the predictive importance of APC mutations, the most common genetic alteration in colorectal cancers, for molecular targeted therapeutics. Mol Cancer Ther; 16(4); 752–62. ©2017 AACR.
Data from APOMAB Antibody–Drug Conjugates Targeting Dead Tumor Cells are Effective In Vivo
Authors: Staudacher Alexander H. , Li Yanrui , Liapis Vasilios , Hou Jeff Jia Cheng , Chin David , Dolezal Olan , Adams Timothy E. , van Berkel Patrick H. , Brown Michael P.
Published: April 2023

Abstract
Antibody–drug conjugates (ADC) have revolutionized the field of cancer therapy. ADCs combine the high specificity of tumor-targeting monoclonal antibodies with potent cytotoxic drugs, which cannot be used alone because of their high toxicity. Till date, all ADCs have either targeted cell membrane proteins on tumors or the tumor vasculature and microenvironment. Here, we investigate ADCs of APOMAB (DAB4, or its chimeric derivative, chDAB4), which is a mAb targeting the La/SSB protein, which is only accessible for binding in dying or dead cancer cells. We show that DAB4-labeled dead cells are phagocytosed by macrophages, and that the apoptotic/necrotic areas within lung tumor xenografts are bound by DAB4 and are infiltrated with macrophages. We show that only DAB4–ADCs with a cleavable linker and diffusible drug are effective in two lung cancer models, particularly when given after chemotherapy. These results are consistent with other recent studies showing that direct internalization of ADCs by target cells is not essential for ADC activity because the linker can be cleaved extracellularly or through other mechanisms. Rather than targeting a tumor cell type specific antigen, DAB4–ADCs have the advantage of targeting a common trait in most solid tumors: an excess of post-apoptotic, necrotic cells either adjacent to hypoxic tumor regions or distributed more generally after cytotoxic therapy. Consequently, any antitumor effects are solely the result of bystander killing, either through internalization of the dead, ADC-bound tumor cells by macrophages, or extracellular cleavage of the ADC in the tumor microenvironment.
Data from 6α-Acetoxyanopterine: A Novel Structure Class of Mitotic Inhibitor Disrupting Microtubule Dynamics in Prostate Cancer Cells
Authors: Levrier Claire , Sadowski Martin C. , Rockstroh Anja , Gabrielli Brian , Kavallaris Maria , Lehman Melanie , Davis Rohan A. , Nelson Colleen C.
Published: April 2023

Abstract
The lack of a cure for metastatic castrate-resistant prostate cancer (mCRPC) highlights the urgent need for more efficient drugs to fight this disease. Here, we report the mechanism of action of the natural product 6α-acetoxyanopterine (6-AA) in prostate cancer cells. At low nanomolar doses, this potent cytotoxic alkaloid from the Australian endemic tree Anopterus macleayanus induced a strong accumulation of LNCaP and PC-3 (prostate cancer) cells as well as HeLa (cervical cancer) cells in mitosis, severe mitotic spindle defects, and asymmetric cell divisions, ultimately leading to mitotic catastrophe accompanied by cell death through apoptosis. DNA microarray of 6-AA–treated LNCaP cells combined with pathway analysis identified very similar transcriptional changes when compared with the anticancer drug vinblastine, which included pathways involved in mitosis, microtubule spindle organization, and microtubule binding. Like vinblastine, 6-AA inhibited microtubule polymerization in a cell-free system and reduced cellular microtubule polymer mass. Yet, microtubule alterations that are associated with resistance to microtubule-destabilizing drugs like vinca alkaloids (vinblastine/vincristine) or 2-methoxyestradiol did not confer resistance to 6-AA, suggesting a different mechanism of microtubule interaction. 6-AA is a first-in-class microtubule inhibitor that features the unique anopterine scaffold. This study provides a strong rationale to further develop this novel structure class of microtubule inhibitor for the treatment of malignant disease. Mol Cancer Ther; 16(1); 3–15. ©2016 AACR.
Data from Novel, Selective Inhibitors of USP7 Uncover Multiple Mechanisms of Antitumor Activity In Vitro and In Vivo
Authors: Ohol Yamini M. , Sun Michael T. , Cutler Gene , Leger Paul R. , Hu Dennis X. , Biannic Berenger , Rana Payal , Cho Cynthia , Jacobson Scott , Wong Steve T. , Sanchez Jerick , Shah Niket , Pookot Deepa , Abraham Betty , Young Kyle , Suthram Silpa , Marshall Lisa A. , Bradford Delia , Kozon Nathan , Han Xinping , Okano Akinori , Maung Jack , Colas Christophe , Schwarz Jacob , Wustrow David , Brockstedt Dirk G. , Kassner Paul D.
Published: April 2023

Abstract
The deubiquitinase USP7 regulates the levels of multiple proteins with roles in cancer progression and immune response. Thus, USP7 inhibition may decrease oncogene function, increase tumor suppressor function, and sensitize tumors to DNA-damaging agents. We have discovered a novel chemical series that potently and selectively inhibits USP7 in biochemical and cellular assays. Our inhibitors reduce the viability of multiple TP53 wild-type cell lines, including several hematologic cancer and MYCN-amplified neuroblastoma cell lines, as well as a subset of TP53-mutant cell lines in vitro. Our work suggests that USP7 inhibitors upregulate transcription of genes normally silenced by the epigenetic repressor complex, polycomb repressive complex 2 (PRC2), and potentiate the activity of PIM and PI3K inhibitors as well as DNA-damaging agents. Furthermore, oral administration of USP7 inhibitors inhibits MM.1S (multiple myeloma; TP53 wild type) and H526 (small cell lung cancer; TP53 mutant) tumor growth in vivo. Our work confirms that USP7 is a promising, pharmacologically tractable target for the treatment of cancer.
Data from HER-Family Ligands Promote Acquired Resistance to Trastuzumab in Gastric Cancer
Authors: Sampera Aïda , Sánchez-Martín Francisco Javier , Arpí Oriol , Visa Laura , Iglesias Mar , Menéndez Sílvia , Gaye Élisabeth , Dalmases Alba , Clavé Sergi , Gelabert-Baldrich Mariona , Poulsen Thomas Tuxen , Kragh Michael , Bellosillo Beatriz , Albanell Joan , Rovira Ana , Montagut Clara
Published: April 2023

Abstract
Despite the clinical benefit of trastuzumab, eventually all HER2-amplified gastric cancer tumors develop drug resistance. We aimed to identify molecular mechanisms of acquired resistance to trastuzumab in gastric cancer by using well-established cell line–based preclinical models, as well as samples from patients with HER2-positive gastric cancer treated with trastuzumab. We studied trastuzumab resistance in NCI-N87 and OE19, two gastric cancer cell lines that overexpress HER2 receptor and are trastuzumab sensitive. Differences at protein, DNA, and RNA levels between the parental and resistant cells were characterized and functional studies were performed. Paired pre- and post-trastuzumab blood and tissue samples from patients with gastric cancer treated with trastuzumab were analyzed. We found that resistant cells were associated with increased activation of MAPK/ERK and PI3K/mTOR pathways driven by SRC activation. Upstream, resistant cells showed increased coexpression of multiple HER-family ligands that allowed for compensatory activation of alternative HER receptors upon HER2 blockade. Simultaneous inhibition of EGFR, HER2, and HER3 by the novel antibody mixture, Pan-HER, effectively reverted trastuzumab resistance in vitro and in vivo. Similarly, an increase in HER-family ligands was observed in serum and tumor from patients with gastric cancer after trastuzumab therapy. We propose that trastuzumab resistance in gastric cancer is mediated by HER-family ligand upregulation that allows a compensatory activation of HER receptors and maintains downstream signaling activation despite trastuzumab therapy. Resistance is reverted by simultaneous inhibition of EGFR, HER2, and HER3, thereby revealing a potential therapeutic strategy to overcome trastuzumab resistance in patients with gastric cancer.
Data from The Novel Histone Deacetylase Inhibitor, OBP-801, Induces Apoptosis in Rhabdoid Tumors by Releasing the Silencing of NOXA
Authors: Sugimoto Yohei , Katsumi Yoshiki , Iehara Tomoko , Kaneda Daisuke , Tomoyasu Chihiro , Ouchi Kazutaka , Yoshida Hideki , Miyachi Mitsuru , Yagyu Shigeki , Kikuchi Ken , Tsuchiya Kunihiko , Kuwahara Yasumichi , Sakai Toshiyuki , Hosoi Hajime
Published: April 2023

Abstract
Rhabdoid tumor is an aggressive, early childhood tumor. Biallelic inactivation of the SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 (SMARCB1)/integrase interactor 1 (INI1) gene is the only common genetic feature in rhabdoid tumors. Loss of SMARCB1 function results in downregulation of several tumor suppressor genes including p16, p21, and NOXA. The novel histone deacetylase inhibitor, OBP-801, induces p21 and has shown efficacy against various cancers. In our study, OBP-801 strongly inhibited the cell growth of all rhabdoid tumor cell lines in WST-8 assay. However, Western blotting and cell-cycle analysis revealed that OBP-801 did not activate the P21-RB pathway in some cell lines. p21 knockout indicated that p21 did not dominate the OBP-801 antitumor effect in rhabdoid tumor cell lines. We discovered that OBP-801 induced NOXA expression and caspase-dependent apoptosis in rhabdoid tumor cell lines independent of TP53. Chromatin immunoprecipitation assay showed that OBP-801 acetylated histone proteins and recruited RNA polymerase II to the transcription start site (TSS) of the NOXA promotor. Moreover, OBP-801 recruited BRG1 and BAF155, which are members of the SWI/SNF complex, to the TSS of the NOXA promotor. These results suggest that OBP-801 epigenetically releases the silencing of NOXA and induces apoptosis in rhabdoid tumors. OBP-801 strongly inhibited tumor growth in human rhabdoid tumor xenograft mouse models in vivo. Terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling and cleaved caspase-3 were stained in tumors treated with OBP-801. In conclusion, OBP-801 induces apoptosis in rhabdoid tumor cells by epigenetically releasing the silencing of NOXA, which is a key mediator of rhabdoid tumor apoptosis. The epigenetic approach for NOXA silencing with OBP-801 is promising for rhabdoid tumor treatment.
Data from Toxicology and Pharmacokinetic Studies in Mice and Nonhuman Primates of the Nontoxic, Efficient, Targeted Hexameric FasL: CTLA4-FasL
Authors: Makdasi Efi , Amsili Shira , Aronin Alexandra , Prigozhina Tatyana B. , Tzdaka Kobi , Gozlan Yosi Meir , Ben Gigi–Tamir Liat , Sagiv Jitka Yehudith , Shkedy Fanny , Shani Noam , Tykocinski Mark L. , Dranitzki Elhalel Michal
Published: April 2023

Abstract
Cytotoxic T-lymphocyte antigen 4 (CTLA4)-FasL, a homo-hexameric signal converter protein, is capable of inducing robust apoptosis in malignant cells of the B-cell lineage expressing its cognate B7 and Fas targets, while sparing nonmalignant ones. This fusion protein's striking proapoptotic efficacy stems from its complementary abilities to coordinately activate apoptotic signals and abrogate antiapoptotic ones. A limiting factor in translating FasL or Fas receptor agonists into the clinic has been lethal hepatotoxicity. Here, we establish CTLA4-FasL's in vivo efficacy in multiple murine and xenograft models, for both systemic and subcutaneous tumors. Significantly, good laboratory practice (GLP) toxicology studies in mice indicate that CTLA4-FasL given repeatedly at doses up to five times the effective dose was well-tolerated and resulted in no significant adverse events. An equivalent single dose of CTLA4-FasL administered to nonhuman primates was also well-tolerated, albeit with a moderate dose-dependent leukopenia that was completely reversible. Interestingly, monkey peripheral blood mononuclear cells were more sensitive to CTLA4-FasL–induced apoptosis when tested in vitro. In both species, there was short-term elevation in serum levels of IL6, IL2, and IFNγ, although this was not associated with clinical signs of proinflammatory cytokine release, and further, this cytokine elevation could be completely prevented by dexamethasone premedication. Liver toxicity was not observed in either species, as confirmed by serum liver enzyme levels and histopathologic assessment. In conclusion, CTLA4-FasL emerges from animal model studies as an effective and safe agent for targeted FasL-mediated treatment of B7-expressing aggressive B-cell lymphomas.
Data from A Highly Potent TACC3 Inhibitor as a Novel Anticancer Drug Candidate
Authors: Akbulut Ozge , Lengerli Deniz , Saatci Ozge , Duman Elif , Seker Urartu O.S. , Isik Aynur , Akyol Aytekin , Caliskan Burcu , Banoglu Erden , Sahin Ozgur
Published: April 2023

Abstract
TACC3, a transforming acidic coiled-coil (TACC) family member, is frequently upregulated in a broad spectrum of cancers, including breast cancer. It plays critical roles in protecting microtubule stability and centrosome integrity that is often dysregulated in cancers; therefore, making TACC3 a highly attractive therapeutic target. Here, we identified a new TACC3-targeting chemotype, BO-264, through the screening of in-house compound collection. Direct interaction between BO-264 and TACC3 was validated by using several biochemical methods, including drug affinity responsive target stability, cellular thermal shift assay, and isothermal titration calorimetry. BO-264 demonstrated superior antiproliferative activity to the two currently reported TACC3 inhibitors, especially in aggressive breast cancer subtypes, basal and HER2+, via spindle assembly checkpoint–dependent mitotic arrest, DNA damage, and apoptosis, while the cytotoxicity against normal breast cells was negligible. Furthermore, BO-264 significantly decreased centrosomal TACC3 during both mitosis and interphase. BO-264 displayed potent antiproliferative activity (∼90% have less than 1 μmol/L GI50 value) in the NCI-60 cell line panel compromising of nine different cancer types. Noteworthy, BO-264 significantly inhibited the growth of cells harboring FGFR3–TACC3 fusion, an oncogenic driver in diverse malignancies. Importantly, its oral administration significantly impaired tumor growth in immunocompromised and immunocompetent breast and colon cancer mouse models, and increased survival without any major toxicity. Finally, TACC3 expression has been identified as strong independent prognostic factor in breast cancer and strongly prognostic in several different cancers. Overall, we identified a novel and highly potent TACC3 inhibitor as a novel potential anticancer agent, inducing spindle abnormalities and mitotic cell death.
Data from PET Imaging of the EPR Effect in Tumor Xenografts Using Small 15 nm Diameter Polyethylene Glycols Labeled with Zirconium-89
Authors: Beckford Vera Denis R. , Fontaine Shaun D. , VanBrocklin Henry F. , Hearn Brian R. , Reid Ralph , Ashley Gary W. , Santi Daniel V.
Published: April 2023

Abstract
The goal was to develop and characterize a companion diagnostic for the releasable PEG40kDa∼SN-38 oncology drug, PLX038, that would identify tumors susceptible to high accumulation of PLX038. PEG conjugates of the zirconium ligand desferroxamine B (DFB) of similar size and charge to PLX038 were prepared that contained one or four DFB, as well as one that contained three SN-38 moieties and one DFB. Uptake and associated kinetic parameters of the 89Zr-labeled nanocarriers were determined in tumor and normal tissues in mice using μPET/CT imaging. The data were fit to physiologically based pharmacokinetic models to simulate the mass-time profiles of distribution of conjugates in the tissues of interest. The time–activity curves for normal tissues showed high levels at the earliest time of measurement due to vascularization, followed by a monophasic loss. In tumors, levels were initially lower than in normal tissues but increased to 9% to 14% of injected dose over several days. The efflux half-life in tumors was very long, approximately 400 hours, and tumor levels remained at about 10% injected dose 9 days after injection. Compared with diagnostic liposomes, the PEG nanocarriers have a longer serum half-life, are retained in tumors at higher levels, remain there longer, and afford higher tumor exposure. The small PEG40kDa nanocarriers studied here show properties for passive targeting of tumors that are superior than most nanoparticles and might be effective probes to identify tumors susceptible to similar size therapeutic nanocarriers such as PLX038.
Data from Prognostic and Predictive Biomarkers in Patients with Metastatic Colorectal Cancer Receiving Regorafenib
Authors: Liu Yingmiao , Lyu Jing , Bell Burdett Kirsten , Sibley Alexander B. , Hatch Ace J. , Starr Mark D. , Brady John C. , Hammond Kelli , Marmorino Federica , Rossini Daniele , Goldberg Richard M. , Falcone Alfredo , Cremolini Chiara , Owzar Kouros , Ivanova Anastasia , Moore Dominic T. , Lee Michael S. , Sanoff Hanna K. , Innocenti Federico , Nixon Andrew B.
Published: April 2023

Abstract
Regorafenib is a tyrosine kinase inhibitor approved by the FDA for the treatment of patients with chemotherapy refractory metastatic colorectal cancer (mCRC). Regorafenib inhibits signaling through multiple receptors associated with angiogenesis, metastasis, and tumor immunity. Here, we report biomarker results from LCCC1029, a randomized, placebo-controlled, phase II trial of chemotherapy ± regorafenib in patients with second-line mCRC. A panel of 20 soluble protein biomarkers (termed the Angiome) was assessed in the plasma of 149 patients from the LCCC1029 trial both at baseline and along the treatment continuum. Baseline protein levels were analyzed for prognostic and predictive value for progression-free survival (PFS) and overall survival (OS). Changes in protein levels during treatment were analyzed for potential pharmacodynamic effects. Six markers (HGF, IL6, PlGF, VEGF-R1, OPN, and IL6R) were found to be prognostic for PFS. Nine markers (IL6, TIMP-1, PlGF, VCAM-1, ICAM-1, OPN, TSP-2, HGF, and VEGF-R1) were prognostic for OS. Higher baseline levels of OPN (Pintx = 0.0167), VCAM-1 (Pintx = 0.0216), and PDGF-AA (Pintx = 0.0435) appeared to predict for PFS benefit from regorafenib compared with placebo. VCAM-1 was also potentially predictive of OS benefit from regorafenib compared with placebo (Pintx = 0.0124). On-treatment changes of six markers reflected potential on-target effect of regorafenib. Consistent results were observed in an Italian cohort where 105 patients with late-stage mCRC received regorafenib monotherapy. The key findings of this study suggest that VCAM-1 may be a predictive biomarker for regorafenib benefit, while multiple protein markers may be prognostic of outcome in patients with mCRC.
Data from Rac Signaling Drives Clear Cell Renal Carcinoma Tumor Growth by Priming the Tumor Microenvironment for an Angiogenic Switch
Authors: Goka Erik T. , Chaturvedi Pallavi , Lopez Dayrelis T. Mesa , Lippman Marc E.
Published: April 2023

Abstract
Clear cell renal cell carcinoma (ccRCC) remains a common cause of cancer mortality. Better understanding of ccRCC molecular drivers resulted in the development of antiangiogenic therapies that block the blood vessels that supply tumors with nutrients for growth and metastasis. Unfortunately, most ccRCC patients eventually become resistant to initial treatments, creating a need for alternative treatment options. We investigated the role of the small GTPase Rac1 in ccRCC. Analysis of ccRCC clinical samples indicates that Rac signaling drives disease progression and predicts patients with poorer outcomes. Investigation of Rac1 identifies multiple roles for Rac1 in the pathogenesis of ccRCC. Rac1 is overexpressed in RCC cell lines and drives proliferation and migratory/metastatic potential. Rac1 is also critical for endothelial cells to grow and form endothelial tubular networks potentiated by angiogenic factors. Importantly, Rac1 controls paracrine signaling of angiogenic factors including VEGF from renal carcinoma cells to surrounding blood vessels. A novel Rac1 inhibitor impaired the growth and migratory potential of both renal carcinoma cells and endothelial cells and reduced VEGF production by RCC cells, thereby limiting paracrine signaling both in vitro and in vivo. Lastly, Rac1 was shown to be downstream of VEGF receptor (VEGFR) signaling and required for activation of MAPK signaling. In combination with VEGFR2 inhibitors, Rac inhibition provides enhanced suppression of angiogenesis. Therefore, targeting Rac in ccRCC has the potential to block the growth of tumor cells, endothelial cell recruitment, and paracrine signaling from tumor cells to other cells in the tumor microenvironment.