bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Targeting Three Distinct HER2 Domains with a Recombinant Antibody Mixture Overcomes Trastuzumab Resistance
Authors: Pedersen Mikkel W. , Jacobsen Helle J. , Koefoed Klaus , Dahlman Anna , Kjær Ida , Poulsen Thomas T. , Meijer Per-Johan , Nielsen Lars S. , Horak Ivan D. , Lantto Johan , Kragh Michael
Published: March 2024

Abstract
HER2 plays an important role in the development and maintenance of the malignant phenotype of several human cancers. As such, it is a frequently pursued therapeutic target and two antibodies targeting HER2 have been clinically approved, trastuzumab and pertuzumab. It has been suggested that optimal inhibition of HER2 is achieved when utilizing two or more antibodies targeting nonoverlapping epitopes. Superior clinical activity of the trastuzumab plus pertuzumab combination in metastatic breast cancer supports this hypothesis. Because trastuzumab and pertuzumab were not codeveloped, there may be potential for further optimizing HER2 targeting. The study herein evaluated functional activity of anti-HER2 antibody combinations identifying optimal epitope combinations that provide efficacious HER2 inhibition. High-affinity antibodies to all four extracellular domains on HER2 were identified and tested for ability to inhibit growth of different HER2-dependent tumor cell lines. An antibody mixture targeting three HER2 subdomains proved to be superior to trastuzumab, pertuzumab, or a combination in vitro and to trastuzumab in two in vivo models. Specifically, the tripartite antibody mixture induced efficient HER2 internalization and degradation demonstrating increased sensitivity in cell lines with HER2 amplification and high EGFR levels. When compared with individual and clinically approved mAbs, the synergistic tripartite antibody targeting HER2 subdomains I, II, and IV demonstrates superior anticancer activity. Mol Cancer Ther; 14(3); 669–80. ©2015 AACR.
Data from Evaluation of Novel Imidazotetrazine Analogues Designed to Overcome Temozolomide Resistance and Glioblastoma Regrowth
Authors: Ramirez Yulian P. , Mladek Ann C. , Phillips Roger M. , Gynther Mikko , Rautio Jarkko , Ross Alonzo H. , Wheelhouse Richard T. , Sakaria Jann N.
Published: March 2024

Abstract
The cellular responses to two new temozolomide (TMZ) analogues, DP68 and DP86, acting against glioblastoma multiforme (GBM) cell lines and primary culture models are reported. Dose–response analysis of cultured GBM cells revealed that DP68 is more potent than DP86 and TMZ and that DP68 was effective even in cell lines resistant to TMZ. On the basis of a serial neurosphere assay, DP68 inhibits repopulation of these cultures at low concentrations. The efficacy of these compounds was independent of MGMT and MMR functions. DP68-induced interstrand DNA cross-links were demonstrated with H2O2-treated cells. Furthermore, DP68 induced a distinct cell–cycle arrest with accumulation of cells in S phase that is not observed for TMZ. Consistent with this biologic response, DP68 induces a strong DNA damage response, including phosphorylation of ATM, Chk1 and Chk2 kinases, KAP1, and histone variant H2AX. Suppression of FANCD2 expression or ATR expression/kinase activity enhanced antiglioblastoma effects of DP68. Initial pharmacokinetic analysis revealed rapid elimination of these drugs from serum. Collectively, these data demonstrate that DP68 is a novel and potent antiglioblastoma compound that circumvents TMZ resistance, likely as a result of its independence from MGMT and mismatch repair and its capacity to cross-link strands of DNA. Mol Cancer Ther; 14(1); 111–9. ©2014 AACR.
Data from Inhibition of PI3K Pathway Reduces Invasiveness and Epithelial-to-Mesenchymal Transition in Squamous Lung Cancer Cell Lines Harboring PIK3CA Gene Alterations
Authors: Bonelli Mara A. , Cavazzoni Andrea , Saccani Francesca , Alfieri Roberta R. , Quaini Federico , La Monica Silvia , Galetti Maricla , Cretella Daniele , Caffarra Cristina , Madeddu Denise , Frati Caterina , Lagrasta Costanza Annamaria , Falco Angela , Rossetti Pietro , Fumarola Claudia , Tiseo Marcello , Petronini Pier Giorgio , Ardizzoni Andrea
Published: March 2024

Abstract
A prominent role in the pathogenesis of squamous cell carcinoma of the lung (SQCLC) has been attributed to the aberrant activation of the PI3K signaling pathway, due to amplification or mutations of the p110α subunit of class I phosphatidylinositol 3-kinase (PIK3CA) gene. The aim of our study was to determine whether different genetic alterations of PIK3CA affect the biologic properties of SQCLC and to evaluate the response to specific targeting agents in vitro and in vivo. The effects of NVP-BEZ235, NVP-BKM120, and NVP-BYL719 on two-dimensional/three-dimensional (2D/3D) cellular growth, epithelial-to-mesenchymal transition, and invasiveness were evaluated in E545K or H1047R PIK3CA–mutated SQCLC cells and in newly generated clones carrying PIK3CA alterations, as well as in a xenograft model. PIK3CA mutated/amplified cells showed increased growth rate and enhanced migration and invasiveness, associated with an increased activity of RhoA family proteins and the acquisition of a mesenchymal phenotype. PI3K inhibitors reverted this aggressive phenotype by reducing metalloproteinase production, RhoA activity, and the expression of mesenchymal markers, with the specific PI3K inhibitors NVP-BKM120 and NVP-BYL719 being more effective than the dual PI3K/mTOR inhibitor NVP-BEZ235. A xenograft model of SQCLC confirmed that PIK3CA mutation promotes the acquisition of a mesenchymal phenotype in vivo and proved the efficacy of its specific targeting drug NVP-BYL719 in reducing the growth and the expression of mesenchymal markers in xenotransplanted tumors. These data indicate that PIK3CA mutation/amplification may represent a good predictive feature for the clinical application of specific PI3K inhibitors in SQCLC patients. Mol Cancer Ther; 14(8); 1916–27. ©2015 AACR.
Data from Anticancer Activity of a Novel Selective CYP17A1 Inhibitor in Preclinical Models of Castrate-Resistant Prostate Cancer
Authors: Toren Paul J. , Kim Soojin , Pham Steven , Mangalji Azzra , Adomat Hans , Guns Emma S. Tomlinson , Zoubeidi Amina , Moore William , Gleave Martin E.
Published: March 2024

Abstract
VT-464 is a novel, nonsteroidal, small-molecule CYP17A1 inhibitor with 17,20-lyase selectivity. This study evaluates the anticancer activity of VT-464 compared with abiraterone (ABI) in castrate-resistant prostate cancer cell lines and xenograft models that are enzalutamide (ENZ)-responsive (C4-2) or ENZ-resistant (MR49C, MR49F). In vitro, androgen receptor (AR) transactivation was assessed by probasin luciferase reporter, whereas AR and AR-regulated genes and steroidogenic pathway enzymes were assessed by Western blot and/or qRT-PCR. The MR49F xenograft model was used to compare effects of oral VT-464 treatment to vehicle and abiraterone acetate (AA). Steroid concentrations were measured using LC-MS chromatography. VT-464 demonstrated a greater decrease in AR transactivation compared with ABI in C4-2 and both ENZ-resistant cell lines. At the gene and protein level, VT-464 suppressed the AR axis to a greater extent compared with ABI. Gene transcripts StAR, CYP17A1, HSD17B3, and SRD5A1 increased following treatment with ABI and to a greater extent with VT-464. In vivo, intratumoral androgen levels were significantly lower after VT-464 or AA treatment compared with vehicle, with the greatest decrease seen with VT-464. Similarly, tumor growth inhibition and PSA decrease trends were greater with VT-464 than with AA. Finally, an AR-antagonist effect of VT-464 independent of CYP17A1 inhibition was observed using luciferase reporter assays, and a direct interaction was confirmed using an AR ligand binding domain biolayer interferometry. These preclinical results suggest greater suppression of the AR axis with VT-464 than ABI that is likely due to both superior selective suppression of androgen synthesis and AR antagonism. Mol Cancer Ther; 14(1); 59–69. ©2014 AACR.
Data from Inhibition of Endoglin–GIPC Interaction Inhibits Pancreatic Cancer Cell Growth
Authors: Pal Krishnendu , Pletnev Alexandre A. , Dutta Shamit K. , Wang Enfeng , Zhao Ruizhi , Baral Aradhita , Yadav Vinod Kumar , Aggarwal Suruchi , Krishnaswamy Soundararajan , Alkharfy Khalid M. , Chowdhury Shantanu , Spaller Mark R. , Mukhopadhyay Debabrata
Published: March 2024

Abstract
Endoglin, a 180-kDa disulfide-linked homodimeric transmembrane receptor protein mostly expressed in tumor-associated endothelial cells, is an endogenous binding partner of GAIP-interacting protein, C terminus (GIPC). Endoglin functions as a coreceptor of TβRII that binds TGFβ and is important for vascular development, and consequently has become a compelling target for antiangiogenic therapies. A few recent studies in gastrointestinal stromal tumor (GIST), breast cancer, and ovarian cancer, however, suggest that endoglin is upregulated in tumor cells and is associated with poor prognosis. These findings indicate a broader role of endoglin in tumor biology, beyond angiogenic effects. The goal of our current study is to evaluate the effects of targeting endoglin in pancreatic cancer both in vitro and in vivo. We analyzed the antiproliferative effect of both RNAi-based and peptide ligand-based inhibition of endoglin in pancreatic cancer cell lines, the latter yielding a GIPC PDZ domain-targeting lipopeptide with notable antiproliferative activity. We further demonstrated that endoglin inhibition induced a differentiation phenotype in the pancreatic cancer cells and sensitized them against conventional chemotherapeutic drug gemcitabine. Most importantly, we have demonstrated the antitumor effect of both RNAi-based and competitive inhibitor–based blocking of endoglin in pancreatic cancer xenograft models in vivo. To our knowledge, this is the first report exploring the effect of targeting endoglin in pancreatic cancer cells. Mol Cancer Ther; 13(10); 2264–75. ©2014 AACR.
Data from Combined Inhibition of Cyclin-Dependent Kinases (Dinaciclib) and AKT (MK-2206) Blocks Pancreatic Tumor Growth and Metastases in Patient-Derived Xenograft Models
Authors: Hu Chaoxin , Dadon Tikva , Chenna Venugopal , Yabuuchi Shinichi , Bannerji Rajat , Booher Robert , Strack Peter , Azad Nilofer , Nelkin Barry D. , Maitra Anirban
Published: March 2024

Abstract
KRAS is activated by mutation in the vast majority of cases of pancreatic cancer; unfortunately, therapeutic attempts to inhibit KRAS directly have been unsuccessful. Our previous studies showed that inhibition of cyclin-dependent kinase 5 (CDK5) reduces pancreatic cancer growth and progression, through blockage of the centrally important RAL effector pathway, downstream of KRAS. In the current study, the therapeutic effects of combining the CDK inhibitor dinaciclib (SCH727965; MK-7965) with the pan-AKT inhibitor MK-2206 were evaluated using orthotopic and subcutaneous patient-derived human pancreatic cancer xenograft models. The combination of dinaciclib (20 mg/kg, i.p., three times a week) and MK-2206 (60 mg/kg, orally, three times a week) dramatically blocked tumor growth and metastasis in all eight pancreatic cancer models examined. Remarkably, several complete responses were induced by the combination treatment of dinaciclib and MK-2206. The striking results obtained in these models demonstrate that the combination of dinaciclib with the pan-AKT inhibitor MK-2206 is promising for therapeutic evaluation in pancreatic cancer, and strongly suggest that blocking RAL in combination with other effector pathways downstream from KRAS may provide increased efficacy in pancreatic cancer. Based on these data, an NCI–CTEP-approved multicenter phase I clinical trial for pancreatic cancer of the combination of dinaciclib and MK-2206 (NCT01783171) has now been opened. Mol Cancer Ther; 14(7); 1532–9. ©2015 AACR.
Data from Antiproliferative Effects of CDK4/6 Inhibition in CDK4-Amplified Human Liposarcoma In Vitro and In Vivo
Authors: Zhang Yi-Xiang , Sicinska Ewa , Czaplinski Jeffrey T. , Remillard Stephen P. , Moss Samuel , Wang Yuchuan , Brain Christopher , Loo Alice , Snyder Eric L. , Demetri George D. , Kim Sunkyu , Kung Andrew L. , Wagner Andrew J.
Published: March 2024

Abstract
Well-differentiated/dedifferentiated liposarcomas (WD/DDLPS) are among the most common subtypes of soft tissue sarcomas. Conventional systemic chemotherapy has limited efficacy and novel therapeutic strategies are needed to achieve better outcomes for patients. The cyclin-dependent kinase 4 (CDK4) gene is highly amplified in more than 95% of WD/DDLPS. In this study, we explored the role of CDK4 and the effects of NVP-LEE011 (LEE011), a novel selective inhibitor of CDK4/CDK6, on a panel of human liposarcoma cell lines and primary tumor xenografts. We found that both CDK4 knockdown by siRNA and inhibition by LEE011 diminished retinoblastoma (RB) phosphorylation and dramatically decreased liposarcoma cell growth. Cell-cycle analysis demonstrated arrest at G0–G1. siRNA-mediated knockdown of RB rescued the inhibitory effects of LEE011, demonstrating that LEE011 decreased proliferation through RB. Oral administration of LEE011 to mice bearing human liposarcoma xenografts resulted in approximately 50% reduction in tumor 18F-fluorodeoxyglucose uptake with decreased tumor biomarkers, including RB phosphorylation and bromodeoxyuridine incorporation in vivo. Continued treatment inhibited tumor growth or induced regression without detrimental effects on mouse weight. After prolonged continuous dosing, reestablishment of RB phosphorylation and cell-cycle progression was noted. These findings validate the critical role of CDK4 in maintaining liposarcoma proliferation through its ability to inactivate RB function, and suggest its potential function in the regulation of survival and metabolism of liposarcoma, supporting the rationale for clinical development of LEE011 for the treatment of WD/DDLPS. Mol Cancer Ther; 13(9); 2184–93. ©2014 AACR.
Data from Chemical Inhibition of Wild-Type p53-Induced Phosphatase 1 (WIP1/PPM1D) by GSK2830371 Potentiates the Sensitivity to MDM2 Inhibitors in a p53-Dependent Manner
Authors: Esfandiari Arman , Hawthorne Thomas A. , Nakjang Sirintra , Lunec John
Published: March 2024

Abstract
Sensitivity to MDM2 inhibitors is widely different among responsive TP53 wild-type cell lines and tumors. Understanding the determinants of MDM2 inhibitor sensitivity is pertinent for their optimal clinical application. Wild-type p53-inducible phosphatase-1 (WIP1) encoded by PPM1D, is activated, gained/amplified in a range of TP53 wild-type malignancies, and is involved in p53 stress response homeostasis. We investigated cellular growth/proliferation of TP53 wild-type and matched mutant/null cell line pairs, differing in PPM1D genetic status, in response to Nutlin-3/RG7388 ± a highly selective WIP1 inhibitor, GSK2830371. We also assessed the effects of GSK2830371 on MDM2 inhibitor-induced p53Ser15 phosphorylation, p53-mediated global transcriptional activity, and apoptosis. The investigated cell line pairs were relatively insensitive to single-agent GSK2830371. However, a non–growth-inhibitory dose of GSK2830371 markedly potentiated the response to MDM2 inhibitors in TP53 wild-type cell lines, most notably in those harboring PPM1D-activating mutations or copy number gain (up to 5.8-fold decrease in GI50). Potentiation also correlated with significant increase in MDM2 inhibitor–induced cell death endpoints that were preceded by a marked increase in a WIP1 negatively regulated substrate, phosphorylated p53Ser15, known to increase p53 transcriptional activity. Microarray-based gene expression analysis showed that the combination treatment increases the subset of early RG7388-induced p53 transcriptional target genes. These findings demonstrate that potent and selective WIP1 inhibition potentiates the response to MDM2 inhibitors in TP53 wild-type cells, particularly those with PPM1D activation or gain, while highlighting the mechanistic importance of p53Ser15 and its potential use as a biomarker for response to this combination regimen. Mol Cancer Ther; 15(3); 379–91. ©2016 AACR.
Data from T-Type Ca2+ Channel Inhibition Sensitizes Ovarian Cancer to Carboplatin
Authors: Dziegielewska Barbara , Casarez Eli V. , Yang Wesley Z. , Gray Lloyd S. , Dziegielewski Jaroslaw , Slack-Davis Jill K.
Published: March 2024

Abstract
Ovarian cancer is the deadliest gynecologic cancer, due in large part to the diagnosis of advanced stage disease, the development of platinum resistance, and inadequate treatment alternatives. Recent studies by our group and others have shown that T-type calcium (Ca2+) channels play a reinforcing role in cancer cell proliferation, cell-cycle progression, and apoptosis evasion. Therefore, we investigated whether T-type Ca2+ channels affect ovarian tumor growth and response to platinum agents. Inhibition of T-type Ca2+ channels with mibefradil or by silencing expression resulted in growth suppression in ovarian cancer cells with a simultaneous increase in apoptosis, which was accompanied by decreased expression of the antiapoptotic gene survivin (BIRC5). Analysis of intracellular signaling revealed mibefradil reduced AKT phosphorylation, increased the levels and nuclear retention of FOXO transcription factors that repress BIRC5 expression, and decreased the expression of FOXM1, which promotes BIRC5 expression. Combining carboplatin with mibefradil synergistically increased apoptosis in vitro. Importantly, mibefradil rendered platinum-resistant ovarian tumors sensitive to carboplatin in a mouse model of peritoneal metastasis. Together, the data provide rationale for future use of T-type channel antagonists together with platinum agents for the treatment of ovarian cancer. Mol Cancer Ther; 15(3); 460–70. ©2016 AACR.
Data from Ref-1/APE1 as a Transcriptional Regulator and Novel Therapeutic Target in Pediatric T-cell Leukemia
Authors: Ding Jixin , Fishel Melissa L. , Reed April M. , McAdams Erin , Czader Magdalena B. , Cardoso Angelo A. , Kelley Mark R.
Published: March 2024

Abstract
The increasing characterization of childhood acute lymphoblastic leukemia (ALL) has led to the identification of multiple molecular targets but has yet to translate into more effective targeted therapies, particularly for high-risk, relapsed T-cell ALL. Searching for master regulators controlling multiple signaling pathways in T-ALL, we investigated the multifunctional protein redox factor-1 (Ref-1/APE1), which acts as a signaling “node” by exerting redox regulatory control of transcription factors important in leukemia. Leukemia patients' transcriptome databases showed increased expression in T-ALL of Ref-1 and other genes of the Ref-1/SET interactome. Validation studies demonstrated that Ref-1 is expressed in high-risk leukemia T cells, including in patient biopsies. Ref-1 redox function is active in leukemia T cells, regulating the Ref-1 target NF-κB, and inhibited by the redox-selective Ref-1 inhibitor E3330. Ref-1 expression is not regulated by Notch signaling, but is upregulated by glucocorticoid treatment. E3330 disrupted Ref-1 redox activity in functional studies and resulted in marked inhibition of leukemia cell viability, including T-ALL lines representing different genotypes and risk groups. Potent leukemia cell inhibition was seen in primary cells from ALL patients, relapsed and glucocorticoid-resistant T-ALL cells, and cells from a murine model of Notch-induced leukemia. Ref-1 redox inhibition triggered leukemia cell apoptosis and downregulation of survival genes regulated by Ref-1 targets. For the first time, this work identifies Ref-1 as a novel molecular effector in T-ALL and demonstrates that Ref-1 redox inhibition results in potent inhibition of leukemia T cells, including relapsed T-ALL. These data also support E3330 as a specific Ref-1 small-molecule inhibitor for leukemia. Mol Cancer Ther; 16(7); 1401–11. ©2017 AACR.
Data from Disruption of TCF/β-Catenin Binding Impairs Wnt Signaling and Induces Apoptosis in Soft Tissue Sarcoma Cells
Authors: Martinez-Font Esther , Felipe-Abrio Irene , Calabuig-Fariñas Silvia , Ramos Rafael , Terrasa Josefa , Vögler Oliver , Alemany Regina , Martín-Broto Javier , Obrador-Hevia Antònia
Published: March 2024

Abstract
Soft tissue sarcomas (STS) are malignant tumors of mesenchymal origin and represent around 1% of adult cancers, being a very heterogeneous group of tumors with more than 50 different subtypes. The Wnt signaling pathway is involved in the development and in the regulation, self-renewal, and differentiation of mesenchymal stem cells, and plays a role in sarcomagenesis. In this study, we have tested pharmacologic inhibition of Wnt signaling mediated by disruption of TCF/β-catenin binding and AXIN stabilization, being the first strategy more efficient in reducing cell viability and downstream effects. We have shown that disruption of TCF/β-catenin binding with PKF118-310 produces in vitro antitumor activity in a panel of prevalent representative STS cell lines and primary cultures. At the molecular level, PKF118-310 treatment reduced β-catenin nuclear localization, reporter activity, and target genes, resulting in an increase in apoptosis. Importantly, combination of PKF118-310 with doxorubicin resulted in enhanced reduction of cell viability, suggesting that Wnt inhibition could be a new combination regime in these patients. Our findings support the usefulness of Wnt inhibitors as new therapeutic strategies for the prevalent STS. Mol Cancer Ther; 16(6); 1166–76. ©2017 AACR.
Data from Pigment Epithelium–Derived Factor Alleviates Tamoxifen-Induced Endometrial Hyperplasia
Authors: Goldberg Keren , Bar-Joseph Hadas , Grossman Hadas , Hasky Noa , Uri-Belapolsky Shiri , Stemmer Salomon M. , Chuderland Dana , Shalgi Ruth , Ben-Aharon Irit
Published: March 2024

Abstract
Tamoxifen is a cornerstone component of adjuvant endocrine therapy for patients with hormone-receptor–positive breast cancer. Its significant adverse effects include uterine hyperplasia, polyps, and increased risk of endometrial cancer. However, the underlying molecular mechanism remains unclear. Excessive angiogenesis, a hallmark of tumorigenesis, is a result of disrupted balance between pro- and anti-angiogenic factors. VEGF is a pro-angiogenic factor shown to be elevated by tamoxifen in the uterus. Pigment epithelium–derived factor (PEDF) is a potent anti-angiogenic factor that suppresses strong pro-angiogenic factors, such as VEGF. Our aim was to investigate whether angiogenic balance plays a role in tamoxifen-induced uterine pathologies, elucidate the molecular impairment in that network, and explore potential intervention to offset the proposed imbalance elicited by tamoxifen. Using in vivo mouse models, we demonstrated that tamoxifen induced a dose-dependent shift in endogenous uterine angiogenic balance favoring VEGF over PEDF. Treatment with recombinant PEDF (rPEDF) abrogated tamoxifen-induced uterine hyperplasia and VEGF elevation, resulting in reduction of blood vessels density. Exploring the molecular mechanism revealed that tamoxifen promoted survival and malignant transformation pathways, whereas rPEDF treatment prevents these changes. Activation of survival pathways was decreased, demonstrated by reduction in AKT phosphorylation concomitant with elevation in JNK phosphorylation. Estrogen receptor-α and c-Myc oncoprotein levels were reduced. Our findings provide novel insight into the molecular mechanisms tamoxifen induces in the uterus, which may become the precursor events of subsequent endometrial hyperplasia and cancer. We demonstrate that rPEDF may serve as a useful intervention to alleviate the risk of tamoxifen-induced endometrial pathologies. Mol Cancer Ther; 14(12); 2840–9. ©2015 AACR.
Data from Combining Onartuzumab with Erlotinib Inhibits Growth of Non–Small Cell Lung Cancer with Activating EGFR Mutations and HGF Overexpression
Authors: Sano Yuji , Hashimoto Eri , Nakatani Noriaki , Abe Masaichi , Satoh Yasuko , Sakata Kiyoaki , Fujii Toshihiko , Fujimoto-Ouchi Kaori , Sugimoto Masamichi , Nagahashi Shigehisa , Aoki Masahiro , Motegi Hiroshi , Sasaki Eiichi , Yatabe Yasushi
Published: March 2024

Abstract
Erlotinib, a tyrosine kinase inhibitor of the epidermal growth factor receptor (EGFR-TKI), benefits survival of patients with non–small cell lung cancer (NSCLC) who harbor activating EGFR mutations. However, elevated expression of hepatocyte growth factor (HGF), a ligand of the MET receptor tyrosine kinase, causes erlotinib resistance. Because onartuzumab, a monovalent antibody to MET, blocks HGF-induced MET activation, the addition of onartuzumab to erlotinib may improve therapeutic efficacy. We engineered the human NSCLC cell line PC-9 (MET-positive cells harboring an exon 19 deletion of EGFR) to overexpress hHGF and evaluated the effects of an onartuzumab and erlotinib combination in vitro and in vivo in xenograft models. A stable clone of PC-9/hHGF was less sensitive to erlotinib than the parental PC-9, and the addition of onartuzumab to erlotinib suppressed the proliferation of these cells in vitro. In PC-9/hHGF xenograft tumors, onartuzumab or erlotinib alone minimally inhibited tumor growth; however, combining onartuzumab and erlotinib markedly suppressed tumor growth. The total MET protein level was decreased in PC-9/hHGF cells, because MET is constitutively phosphorylated by autocrine HGF, leading to its ubiquitination and degradation. Onartuzumab reduced phospho-MET levels, inhibited MET ubiquitination, and consequently restored MET protein levels. Moreover, in NSCLC clinical specimens harboring activating EGFR mutations, more than 30% of patients expressed high levels of HGF. Our findings raised the possibility that patients with NSCLC with EGFR mutations who express high levels of HGF may benefit from onartuzumab and erlotinib combination therapy, and that HGF can be a novel biomarker for selecting such patients. Mol Cancer Ther; 14(2); 533–41. ©2014 AACR.
Data from Neuregulin 1 Allosterically Enhances the Antitumor Effects of the Noncompeting Anti-HER3 Antibody 9F7-F11 by Increasing Its Binding to HER3
Authors: Le Clorennec Christophe , Bazin Hervé , Dubreuil Olivier , Larbouret Christel , Ogier Charline , Lazrek Yassamine , Garambois Véronique , Poul Marie-Alix , Mondon Philippe , Barret Jean-Marc , Mathis Gérard , Prost Jean-François , Pèlegrin André , Chardès Thierry
Published: March 2024

Abstract
Exploratory clinical trials using therapeutic anti-HER3 antibodies strongly suggest that neuregulin (NRG1; HER3 ligand) expression at tumor sites is a predictive biomarker of anti-HER3 antibody efficacy in cancer. We hypothesized that in NRG1-expressing tumors, where the ligand is present before antibody treatment, anti-HER3 antibodies that do not compete with NRG1 for receptor binding have a higher receptor-neutralizing action than antibodies competing with the ligand for binding to HER3. Using time-resolved–fluorescence energy transfer (TR-FRET), we demonstrated that in the presence of recombinant NRG1, binding of 9F7-F11 (a nonligand-competing anti-HER3 antibody) to HER3 is increased, whereas that of ligand-competing anti-HER3 antibodies (H4B-121, U3-1287, Ab#6, Mab205.10.2, and MOR09825) is decreased. Moreover, 9F7-F11 showed higher efficacy than antibodies that compete with the ligand for binding to HER3. Specifically, 9F7-F11 inhibition of cell proliferation and of HER3/AKT/ERK1/2 phosphorylation as well as 9F7-F11–dependent cell-mediated cytotoxicity were higher in cancer cells preincubated with recombinant NRG1 compared with cells directly exposed to the anti-HER3 antibody. This translated in vivo into enhanced growth inhibition of NRG1-expressing BxPC3 pancreatic, A549 lung, and HCC-1806 breast cell tumor xenografts in mice treated with 9F7-F11 compared with H4B-121. Conversely, both antibodies had similar antitumor effect in NRG1-negative HPAC pancreatic carcinoma cells. In conclusion, the allosteric modulator 9F7-F11 shows increased anticancer effectiveness in the presence of NRG1 and thus represents a novel treatment strategy for NRG1-addicted tumors. Mol Cancer Ther; 16(7); 1312–23. ©2017 AACR.
Data from Differential Therapeutic Effects of Anti–VEGF-A Antibody in Different Tumor Models: Implications for Choosing Appropriate Tumor Models for Drug Testing
Authors: Alishekevitz Dror , Bril Rotem , Loven David , Miller Valeria , Voloshin Tali , Gingis-Velistki Svetlana , Fremder Ella , Scherer Stefan J. , Shaked Yuval
Published: March 2024

Abstract
We previously reported that the host response to certain chemotherapies can induce primary tumor regrowth, angiogenesis, and even metastases in mice, but the possible impact of anti–VEGF-A therapy in this context has not been fully explored. We, therefore, used combinations of anti–VEGF-A with chemotherapy on various tumor models in mice, including primary tumors, experimental lung metastases, and spontaneous lung metastases of 4T1-breast and CT26-colon murine cancer cell lines. Our results show that a combined treatment with anti–VEGF-A and folinic acid/5-fluorouracil/oxaliplatin (FOLFOX) but not with anti–VEGF-A and gemcitabine/cisplatinum (Gem/CDDP) enhances the treatment outcome partly due to reduced angiogenesis, in both primary tumors and experimental lung metastases models. However, neither treatment group exhibited an improved treatment outcome in the spontaneous lung metastases model, nor were changes in endothelial cell numbers found at metastatic sites. As chemotherapy has recently been shown to induce tumor cell invasion, we tested the invasion properties of tumor cells when exposed to plasma from FOLFOX-treated mice or patients with cancer. While plasma from FOLFOX-treated mice or patients induced invasion properties of tumor cells, the combination of anti–VEGF-A and FOLFOX abrogated these effects, despite the reduced plasma VEGF-A levels detected in FOLFOX-treated mice. These results suggest that the therapeutic impact of antiangiogenic drugs varies in different tumor models, and that anti–VEGF-A therapy can block the invasion properties of tumor cells in response to chemotherapy. These results may implicate an additional therapeutic role for anti–VEGF-A when combined with chemotherapy. Mol Cancer Ther; 13(1); 202–13. ©2013 AACR.
Data from Targeting BRG1 Chromatin Remodeler via Its Bromodomain for Enhanced Tumor Cell Radiosensitivity In Vitro and In Vivo
Authors: Kwon Su-Jung , Lee Seul-Ki , Na Juri , Lee Shin-Ai , Lee Han-Sae , Park Ji-Hye , Chung June-Key , Youn Hyewon , Kwon Jongbum
Published: March 2024

Abstract
Radiotherapy treats cancer by inducing DNA double-strand breaks (DSB) in tumor cells using ionizing radiation. However, DNA repair in tumor cells often leads to radioresistance and unsuccessful outcome. Inhibition of DNA repair by targeting repair proteins can increase radiosensitivity of tumor cells. The BRG1 chromatin remodeling enzyme assists DSB repair by stimulating γ-H2AX formation and BRG1 binding to acetylated histones at DSBs via bromodomain (BRD) is critical for this activity. Here, we show that ectopic expression of BRG1-BRD inhibited γ-H2AX and DSB repair after irradiation and increased the radiosensitivity in various human cancer cells, including HT29 colon cancer. Dimerization of BRG1-BRD, increasing its chromatin binding affinity, aggravated the defects in γ-H2AX and DSB repair and further enhanced the radiosensitivity. While little affecting the upstream ATM activation, BRG1-BRD in irradiated HT29 cells inhibited the recruitment of 53BP1 to damaged chromatin, the downstream event of γ-H2AX, and compromised the G2–M checkpoint and increased apoptosis. Importantly, in a xenograft mouse model, BRG1-BRD increased the radiosensitivity of HT29 tumors, which was further enhanced by dimerization. These data suggest that BRG1-BRD radiosensitizes tumor cells by a dominant negative activity against BRG1, which disrupts γ-H2AX and its downstream 53BP1 pathways, leading to inefficient DNA repair, G2–M checkpoint defect, and increased apoptosis. This work therefore identifies BRG1-BRD as a novel tumor radiosensitizer and its action mechanism, providing the first example of chromatin remodeler as a target for improving cancer radiotherapy. Mol Cancer Ther; 14(2); 597–607. ©2014 AACR.
Data from The Selective Intravenous Inhibitor of the MET Tyrosine Kinase SAR125844 Inhibits Tumor Growth in MET-Amplified Cancer
Authors: Egile Coumaran , Kenigsberg Mireille , Delaisi Christine , Bégassat Françoise , Do-Vale Véronique , Mestadier Jessica , Bonche Fabrice , Bénard Tsiala , Nicolas Jean-Paul , Valence Sandrine , Lefranc Céline , Francesconi Elisa , Castell Christelle , Lefebvre Anne-Marie , Nemecek Conception , Calvet Loreley , Goulaouic Hélène
Published: March 2024

Abstract
Activation of the MET/HGF pathway is common in human cancer and is thought to promote tumor initiation, metastasis, angiogenesis, and resistance to diverse therapies. We report here the pharmacologic characterization of the triazolopyridazine derivative SAR125844, a potent and highly selective inhibitor of the MET receptor tyrosine kinase (RTK), for intravenous administration. SAR125844 displayed nanomolar activity against the wild-type kinase (IC50 value of 4.2 nmol/L) and the M1250T and Y1235D mutants. Broad biochemical profiling revealed that SAR125844 was highly selective for MET kinase. SAR125844 inhibits MET autophosphorylation in cell-based assays in the nanomolar range, and promotes low nanomolar proapoptotic and antiproliferative activities selectively in cell lines with MET gene amplification or pathway addiction. In two MET-amplified human gastric tumor xenograft models, SNU-5 and Hs 746T, intravenous treatment with SAR125844 leads to potent, dose- and time-dependent inhibition of the MET kinase and to significant impact on downstream PI3K/AKT and RAS/MAPK pathways. Long duration of MET kinase inhibition up to 7 days was achieved with a nanosuspension formulation of SAR125844. Daily or every-2-days intravenous treatment of SAR125844 promoted a dose-dependent tumor regression in MET-amplified human gastric cancer models at tolerated doses without treatment-related body weight loss. Our data demonstrated that SAR125844 is a potent and selective MET kinase inhibitor with a favorable preclinical toxicity profile, supporting its clinical development in patients with MET-amplified and MET pathway–addicted tumors. Mol Cancer Ther; 14(2); 384–94. ©2014 AACR.
Data from A Novel Compound, NK150460, Exhibits Selective Antitumor Activity against Breast Cancer Cell Lines through Activation of Aryl Hydrocarbon Receptor
Authors: Fukasawa Kazuteru , Kagaya Shigehide , Maruyama Sakiko , Kuroiwa Shunsuke , Masuda Kuniko , Kameyama Yoshio , Satoh Yoshitaka , Akatsu Yuichi , Tomura Arihiro , Nishikawa Kiyohiro , Horie Shigeo , Ichikawa Yuh-ichiro
Published: March 2024

Abstract
Antiestrogen agents are commonly used to treat patients with estrogen receptor (ER)–positive breast cancer. Tamoxifen has been the mainstay of endocrine treatment for patients with early and advanced breast cancer for many years. Following tamoxifen treatment failure, however, there are still limited options for subsequent hormonal therapy. We discovered a novel compound, NK150460, that inhibits 17β-estradiol (E2)–dependent transcription without affecting binding of E2 to ER. Against our expectations, NK150460 inhibited growth of not only most ER-positive, but also some ER-negative breast cancer cell lines, while never inhibiting growth of non–breast cancer cell lines. Cell-based screening using a random shRNA library, identified aryl hydrocarbon receptor nuclear translocator (ARNT) as a key gene involved in NK150460′s antitumor mechanism. siRNAs against not only ARNT but also its counterpart aryl hydrocarbon receptor (AhR) and their target protein, CYP1A1, dramatically abrogated NK150460′s growth-inhibitory activity. This suggests that the molecular cascade of AhR/ARNT plays an essential role in NK150460′s antitumor mechanism. Expression of ERα was decreased by NK150460 treatment, and this was inhibited by an AhR antagonist. Unlike two other AhR agonists now undergoing clinical developmental stage, NK150460 did not induce histone H2AX phosphorylation or p53 expression, suggesting that it did not induce a DNA damage response in treated cells. Cell lines expressing epithelial markers were more sensitive to NK150460 than mesenchymal marker-expressing cells. These data indicate that NK150460 is a novel AhR agonist with selective antitumor activity against breast cancer cell lines, and its features differ from those of the other two AhR agonists. Mol Cancer Ther; 14(2); 343–54. ©2014 AACR.
Data from Lectin, Galactoside-Binding Soluble 3 Binding Protein Promotes 17-N-Allylamino-17-demethoxygeldanamycin Resistance through PI3K/Akt Pathway in Lung Cancer Cell Line
Authors: Woo Jong Kyu , Jang Jeong-Eun , Kang Ju-Hee , Seong Je Kyung , Yoon Yeo Sung , Kim Hyoung-Chin , Lee Sang-Jin , Oh Seung Hyun
Published: March 2024

Abstract
Heat shock protein 90 (HSP90) stabilizing oncoproteins has been an attractive target in cancer therapy. 17-N-Allylamino-17-demethoxygeldanamycin (17-AAG), an HSP90 inhibitor, was tested in phase II/III clinical trials, but due to lack of efficacy, clinical evaluation of 17-AAG has achieved limited success, which led to resistance to 17-AAG. However, the mechanism of 17-AAG resistance has not clearly been identified. Here, we identified LGALS3BP (Lectin, galactoside-binding soluble 3 binding protein), a secretory glycoprotein, as a 17-AAG resistance factor. In the clinical reports, it was suggested that LGALS3BP was associated with low survival rate, development of cancer progression, and enhancement of metastasis in human cancers. As we confirmed that the LGALS3BP level was increased in 17-AAG–resistant cells (H1299_17R) compared with that of the parental cell line (H1299_17P), knockdown of LGALS3BP expression increased sensitivity to 17-AAG in H1299_17R cells. Overexpression of LGALS3BP also augmented PI3K/Akt and ERK signaling pathways. Furthermore, we determined that the PI3K/Akt signaling pathway was involved in LGALS3BP-mediated 17-AAG resistance in vitro and in vivo, demonstrating that LGALS3BP mediates the resistance against 17-AAG through PI3K/Akt activation rather than ERK activation. These findings suggest that LGALS3BP would be a target to overcome resistance to 17-AAG in lung cancer. For example, the combination of 17-AAG and PI3K/Akt inhibitor would effectively suppress acquired resistance to 17-AAG. In conclusion, targeting of LGALS3BP-mediated–specific survival signaling pathway in resistant cells may provide a novel therapeutic model for the cancer therapy. Mol Cancer Ther; 16(7); 1355–65. ©2017 AACR.
Data from Systemic Administration and Targeted Radiosensitization via Chemically Synthetic Aptamer–siRNA Chimeras in Human Tumor Xenografts
Authors: Ni Xiaohua , Zhang Yonggang , Zennami Kenji , Castanares Mark , Mukherjee Amarnath , Raval Raju R. , Zhou Haoming , DeWeese Theodore L. , Lupold Shawn E.
Published: March 2024

Abstract
Radiation therapy is a highly effective tool for treating all stages of prostate cancer, from curative approaches in localized disease to palliative care and enhanced survival for patients with distant bone metastases. The therapeutic index of these approaches may be enhanced with targeted radiation-sensitizing agents. Aptamers are promising nucleic acid delivery agents for short interfering RNAs (siRNA) and short hairpin RNAs (shRNA). We have previously developed a radiation-sensitizing RNA aptamer–shRNA chimera that selectively delivers DNA-PK targeting shRNAs to prostate-specific membrane antigen (PSMA) positive cells in the absence of transfection reagents. Although these chimera are effective, their synthesis requires in vitro transcription and their evaluation was limited to intratumoral administration. Here, we have developed a second-generation aptamer–siRNA chimera that can be assembled through the annealing of three separate chemically synthesized components. The resulting chimera knocked down DNA-PK in PSMA-positive prostate cancer cells, without the need of additional transfection reagents, and enhanced the efficacy of radiation-mediated cell death. Following intravenous injection, the chimera effectively knocked down DNA-PK in established subcutaneous PSMA-positive tumors. Systemic treatment with these radiation-sensitizing agents selectively enhanced the potency of external beam radiation therapy for established PSMA-positive tumors. Mol Cancer Ther; 14(12); 2797–804. ©2015 AACR.
Data from Efficacy of PARP Inhibitor Rucaparib in Orthotopic Glioblastoma Xenografts Is Limited by Ineffective Drug Penetration into the Central Nervous System
Authors: Parrish Karen E. , Cen Ling , Murray James , Calligaris David , Kizilbash Sani , Mittapalli Rajendar K. , Carlson Brett L. , Schroeder Mark A. , Sludden Julieann , Boddy Alan V. , Agar Nathalie Y.R. , Curtin Nicola J. , Elmquist William F. , Sarkaria Jann N.
Published: March 2024

Abstract
PARP inhibition can enhance the efficacy of temozolomide and prolong survival in orthotopic glioblastoma (GBM) xenografts. The aim of this study was to evaluate the combination of the PARP inhibitor rucaparib with temozolomide and to correlate pharmacokinetic and pharmacodynamic studies with efficacy in patient-derived GBM xenograft models. The combination of rucaparib with temozolomide was highly effective in vitro in short-term explant cultures derived from GBM12, and, similarly, the combination of rucaparib and temozolomide (dosed for 5 days every 28 days for 3 cycles) significantly prolonged the time to tumor regrowth by 40% in heterotopic xenografts. In contrast, the addition of rucaparib had no impact on the efficacy of temozolomide in GBM12 or GBM39 orthotopic models. Using Madin-Darby canine kidney (MDCK) II cells stably expressing murine BCRP1 or human MDR1, cell accumulation studies demonstrated that rucaparib is transported by both transporters. Consistent with the influence of these efflux pumps on central nervous system drug distribution, Mdr1a/b−/−Bcrp1−/− knockout mice had a significantly higher brain to plasma ratio for rucaparib (1.61 ± 0.25) than wild-type mice (0.11 ± 0.08). A pharmacokinetic and pharmacodynamic evaluation after a single dose confirmed limited accumulation of rucaparib in the brain is associated with substantial residual PARP enzymatic activity. Similarly, matrix-assisted laser desorption/ionization mass spectrometric imaging demonstrated significantly enhanced accumulation of drug in flank tumor compared with normal brain or orthotopic tumors. Collectively, these results suggest that limited drug delivery into brain tumors may significantly limit the efficacy of rucaparib combined with temozolomide in GBM. Mol Cancer Ther; 14(12); 2735–43. ©2015 AACR.
Data from Tetravalent Antibody–scTRAIL Fusion Proteins with Improved Properties
Authors: Seifert Oliver , Plappert Aline , Fellermeier Sina , Siegemund Martin , Pfizenmaier Klaus , Kontermann Roland E.
Published: March 2024

Abstract
We applied the immunoglobulin E (IgE) heavy-chain domain 2 (EHD2) as the covalently linked homodimerization module to generate antibody–scTRAIL fusion proteins. By fusing a humanized single-chain fragment variable (scFv) directed against EGFR to the N-terminus of the EHD2 and a single-chain derivative of TRAIL (scTRAIL) to the C-terminus of the EHD2, we produced a dimeric, tetravalent fusion protein. The fusion protein retained its binding activity for EGFR and TRAIL receptors. In vitro, the targeted antibody–scTRAIL fusion protein exhibited an approximately 8- to 18-fold increased cytotoxic activity compared with the untargeted EHD2-scTRAIL fusion protein. This resulted in increased antitumor activity in a subcutaneous Colo205 xenograft tumor murine model. In summary, the scFv-EHD2-scTRAIL fusion protein combines target cell selectivity with an increased TRAIL activity leading to improved antitumor activities. Mol Cancer Ther; 13(1); 101–11. ©2013 AACR.
Data from Biological Role and Therapeutic Targeting of TGF-β3 in Glioblastoma
Authors: Seystahl Katharina , Papachristodoulou Alexandros , Burghardt Isabel , Schneider Hannah , Hasenbach Kathy , Janicot Michel , Roth Patrick , Weller Michael
Published: March 2024

Abstract
Transforming growth factor (TGF)-β contributes to the malignant phenotype of glioblastoma by promoting invasiveness and angiogenesis and creating an immunosuppressive microenvironment. So far, TGF-β1 and TGF-β2 isoforms have been considered to act in a similar fashion without isoform-specific function in glioblastoma. A pathogenic role for TGF-β3 in glioblastoma has not been defined yet. Here, we studied the expression and functional role of endogenous and exogenous TGF-β3 in glioblastoma models. TGF-β3 mRNA is expressed in human and murine long-term glioma cell lines as well as in human glioma-initiating cell cultures with expression levels lower than TGF-β1 or TGF-β2 in most cell lines. Inhibition of TGF-β3 mRNA expression by ISTH2020 or ISTH2023, two different isoform-specific phosphorothioate locked nucleic acid (LNA)-modified antisense oligonucleotide gapmers, blocks downstream SMAD2 and SMAD1/5 phosphorylation in human LN-308 cells, without affecting TGF-β1 or TGF-β2 mRNA expression or protein levels. Moreover, inhibition of TGF-β3 expression reduces invasiveness in vitro. Interestingly, depletion of TGF-β3 also attenuates signaling evoked by TGF-β1 or TGF-β2. In orthotopic syngeneic (SMA-560) and xenograft (LN-308) in vivo glioma models, expression of TGF-β3 as well as of the downstream target, plasminogen-activator-inhibitor (PAI)-1, was reduced, while TGF-β1 and TGF-β2 levels were unaffected following systemic treatment with TGF-β3-specific antisense oligonucleotides. We conclude that TGF-β3 might function as a gatekeeper controlling downstream signaling despite high expression of TGF-β1 and TGF-β2 isoforms. Targeting TGF-β3 in vivo may represent a promising strategy interfering with aberrant TGF-β signaling in glioblastoma. Mol Cancer Ther; 16(6); 1177–86. ©2017 AACR.
Data from Direct Pharmacological Inhibition of β-Catenin by RNA Interference in Tumors of Diverse Origin
Authors: Ganesh Shanthi , Koser Martin L. , Cyr Wendy A. , Chopda Girish R. , Tao Junyan , Shui Xue , Ying Bo , Chen Dongyu , Pandya Purva , Chipumuro Edmond , Siddiquee Zakir , Craig Kevin , Lai Chengjung , Dudek Henryk , Monga Satdarshan P. , Wang Weimin , Brown Bob D. , Abrams Marc T.
Published: March 2024

Abstract
The Wnt/β-catenin pathway is among the most frequently altered signaling networks in human cancers. Despite decades of preclinical and clinical research, efficient therapeutic targeting of Wnt/β-catenin has been elusive. RNA interference (RNAi) technology silences genes at the mRNA level and therefore can be applied to previously undruggable targets. Lipid nanoparticles (LNP) represent an elegant solution for the delivery of RNAi-triggering oligonucleotides to disease-relevant tissues, but have been mostly restricted to applications in the liver. In this study, we systematically tuned the composition of a prototype LNP to enable tumor-selective delivery of a Dicer-substrate siRNA (DsiRNA) targeting CTNNB1, the gene encoding β-catenin. This formulation, termed EnCore-R, demonstrated pharmacodynamic activity in subcutaneous human tumor xenografts, orthotopic patient-derived xenograft (PDX) tumors, disseminated hematopoietic tumors, genetically induced primary liver tumors, metastatic colorectal tumors, and murine metastatic melanoma. DsiRNA delivery was homogeneous in tumor sections, selective over normal liver and independent of apolipoprotein-E binding. Significant tumor growth inhibition was achieved in Wnt-dependent colorectal and hepatocellular carcinoma models, but not in Wnt-independent tumors. Finally, no evidence of accelerated blood clearance or sustained liver transaminase elevation was observed after repeated dosing in nonhuman primates. These data support further investigation to gain mechanistic insight, optimize dose regimens, and identify efficacious combinations with standard-of-care therapeutics. Mol Cancer Ther; 15(9); 2143–54. ©2016 AACR.