bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from A Bifunctional MAPK/PI3K Antagonist for Inhibition of Tumor Growth and Metastasis
Authors: Galbán Stefanie , Apfelbaum April A. , Espinoza Carlos , Heist Kevin , Haley Henry , Bedi Karan , Ljungman Mats , Galbán Craig J. , Luker Gary D. , Dort Marcian Van , Ross Brian D.
Published: March 2024

Abstract
Responses to targeted therapies frequently are brief, with patients relapsing with drug-resistant tumors. For oncogenic MEK and BRAF inhibition, drug resistance commonly occurs through activation of PI3K/AKT/mTOR signaling and immune checkpoint modulation, providing a robust molecular target for concomitant therapy. Here, we evaluated the efficacy of a bifunctional kinase inhibitor (ST-162) that concurrently targets MAPK and PI3K signaling pathways. Treatment with ST-162 produced regression of mutant KRAS- or BRAF-addicted xenograft models of colorectal cancer and melanoma and stasis of BRAF/PTEN–mutant melanomas. Combining ST-162 with immune checkpoint blockers further increased efficacy in a syngeneic KRAS-mutant colorectal cancer model. Nascent transcriptome analysis revealed a unique gene set regulated by ST-162 related to melanoma metastasis. Subsequent mouse studies revealed ST-162 was a potent inhibitor of melanoma metastasis to the liver. These findings highlight the significant potential of a single molecule with multikinase activity to achieve tumor control, overcome resistance, and prevent metastases through modulation of interconnected cell signaling pathways. Mol Cancer Ther; 16(11); 2340–50. ©2017 AACR.
Data from Inhibition of the V-ATPase by Archazolid A: A New Strategy to Inhibit EMT
Authors: Merk Henriette , Messer Philipp , Ardelt Maximilian A. , Lamb Don C. , Zahler Stefan , Müller Rolf , Vollmar Angelika M. , Pachmayr Johanna
Published: March 2024

Abstract
Epithelial–mesenchymal transition (EMT) induces tumor-initiating cells (TIC), which account for tumor recurrence, metastasis, and therapeutic resistance. Strategies to interfere with EMT are rare but urgently needed to improve cancer therapy. By using the myxobacterial natural compound Archazolid A as a tool, we elucidate the V-ATPase, a multimeric proton pump that regulates lysosomal acidification, as a crucial player in EMT and identify the inhibition of V-ATPase by Archazolid A as a promising strategy to block EMT. Genetic knockdown and pharmacologic inhibition of the V-ATPase by Archazolid A interfere with the EMT process and inhibit TIC generation, as shown by a reduced formation of mammospheres and decreased cell motility. As an underlying mechanism, V-ATPase inhibition by Archazolid A disturbs the turnover of E-cadherin: Archazolid abrogates E-cadherin loss during EMT by interfering with its internalization and recycling. Our study elucidates V-ATPase as essential player in EMT by regulating E-cadherin turnover. Archazolid A is suggested as a promising therapeutic agent to block EMT and the generation of TICs. Mol Cancer Ther; 16(11); 2329–39. ©2017 AACR.
Data from Selective Glucocorticoid Receptor Modulators (SGRMs) Delay Castrate-Resistant Prostate Cancer Growth
Authors: Kach Jacob , Long Tiha M. , Selman Phillip , Tonsing-Carter Eva Y. , Bacalao Maria A. , Lastra Ricardo R. , de Wet Larischa , Comiskey Shane , Gillard Marc , VanOpstall Calvin , West Diana C. , Chan Wen-Ching , Griend Donald Vander , Conzen Suzanne D. , Szmulewitz Russell Z.
Published: March 2024

Abstract
Increased glucocorticoid receptor (GR) expression and activity following androgen blockade can contribute to castration-resistant prostate cancer (CRPC) progression. Therefore, we hypothesized that GR antagonism will have therapeutic benefit in CRPC. However, the FDA-approved nonselective, steroidal GR antagonist, mifepristone, lacks GR specificity, reducing its therapeutic potential. Here, we report that two novel nonsteroidal and highly selective GR modulators (SGRM), CORT118335 and CORT108297, have the ability to block GR activity in prostate cancer and slow CRPC progression. In contrast to mifepristone, these novel SGRMs did not affect androgen receptor (AR) signaling, but potently inhibited GR transcriptional activity. Importantly, SGRMs decreased GR-mediated tumor cell viability following AR blockade. In vivo, SGRMs significantly inhibited CRPC progression in high GR–expressing, but not in low GR–expressing xenograft models. Transcriptome analysis following AR blockade and GR activation revealed that these SGRMs block GR-mediated proliferative gene expression pathways. Furthermore, GR-regulated proliferation-associated genes AKAP12, FKBP5, SGK1, CEBPD, and ZBTB16 are inhibited by CORT108297 treatment in vivo. Together, these data suggest that GR-selective nonsteroidal SGRMs potently inhibit GR activity and prostate cancer growth despite AR pathway inhibition, demonstrating the therapeutic potential of SGRMs in GR-expressing CRPC. Mol Cancer Ther; 16(8); 1680–92. ©2017 AACR.
Data from A Novel Recombinant Anti-CD22 Immunokinase Delivers Proapoptotic Activity of Death-Associated Protein Kinase (DAPK) and Mediates Cytotoxicity in Neoplastic B Cells
Authors: Lilienthal Nils , Lohmann Gregor , Crispatzu Giuliano , Vasyutina Elena , Zittrich Stefan , Mayer Petra , Herling Carmen Diana , Tur Mehmet Kemal , Hallek Michael , Pfitzer Gabriele , Barth Stefan , Herling Marco
Published: March 2024

Abstract
The serine/threonine death-associated protein kinases (DAPK) provide pro-death signals in response to (oncogenic) cellular stresses. Lost DAPK expression due to (epi)genetic silencing is found in a broad spectrum of cancers. Within B-cell lymphomas, deficiency of the prototypic family member DAPK1 represents a predisposing or early tumorigenic lesion and high-frequency promoter methylation marks more aggressive diseases. On the basis of protein studies and meta-analyzed gene expression profiling data, we show here that within the low-level context of B-lymphocytic DAPK, particularly CLL cells have lost DAPK1 expression. To target this potential vulnerability, we conceptualized B-cell–specific cytotoxic reconstitution of the DAPK1 tumor suppressor in the format of an immunokinase. After rounds of selections for its most potent cytolytic moiety and optimal ligand part, a DK1KD-SGIII fusion protein containing a constitutive DAPK1 mutant, DK1KD, linked to the scFv SGIII against the B-cell–exclusive endocytic glyco-receptor CD22 was created. Its high purity and large-scale recombinant production provided a stable, selectively binding, and efficiently internalizing construct with preserved robust catalytic activity. DK1KD-SGIII specifically and efficiently killed CD22-positive cells of lymphoma lines and primary CLL samples, sparing healthy donor– or CLL patient–derived non-B cells. The mode of cell death was predominantly PARP-mediated and caspase-dependent conventional apoptosis as well as triggering of an autophagic program. The notoriously high apoptotic threshold of CLL could be overcome by DK1KD-SGIII in vitro also in cases with poor prognostic features, such as therapy resistance. The manufacturing feasibility of the novel CD22-targeting DAPK immunokinase and its selective antileukemic efficiency encourage intensified studies towards specific clinical application. Mol Cancer Ther; 15(5); 971–84. ©2016 AACR.
Data from Acquired Resistance Mechanisms to Combination Met-TKI/EGFR-TKI Exposure in Met-Amplified EGFR-TKI–Resistant Lung Adenocarcinoma Harboring an Activating EGFR Mutation
Authors: Yamaoka Toshimitsu , Ohmori Tohru , Ohba Motoi , Arata Satoru , Kishino Yasunari , Murata Yasunori , Kusumoto Sojiro , Ishida Hiroo , Shirai Takao , Hirose Takashi , Ohnishi Tsukasa , Sasaki Yasutsuna
Published: March 2024

Abstract
Met-amplified EGFR-tyrosine kinase inhibitor (TKI)-resistant non–small cell lung cancer (NSCLC) harboring an activating EGFR mutation is responsive to concurrent EGFR-TKI and Met-TKI treatment in a preclinical model. Here, we determined that Met-amplified gefitinib-resistant cells acquire dual resistance to inhibition of EGFR and Met tyrosine kinase activities. PC-9 lung adenocarcinoma cells harboring 15-bp deletions (Del E746_A750) in EGFR exon 19 were treated with increasing concentrations of the Met-TKI PHA665752 and 1 μmol/L gefitinib for 1 year; three resistant clones were established via Met amplification. The three dual-resistance cell lines (PC-9DR2, PC-9DR4, and PC-9DR6, designated as DR2, DR4, and DR6, respectively) exhibited different mechanisms for evading both EGFR and Met inhibition. None of the clones harbored a secondary mutation of EGFR T790M or a Met mutation. Insulin-like growth factor (IGF)/IGF1 receptor activation in DR2 and DR4 cells acted as a bypass signaling pathway. Met expression was attenuated to a greater extent in DR2 than in PC-9 cells, but was maintained in DR4 cells by overexpression of IGF-binding protein 3. In DR6 cells, Met was further amplified by association with HSP90, which protected Met from degradation and induced SET and MYND domain-containing 3 (SMYD3)-mediated Met transcription. This is the first report describing the acquisition of dual resistance mechanisms in NSCLC harboring an activating EGFR mutation to Met-TKI and EGFR-TKI following previous EGFR-TKI treatment. These results might inform the development of more effective therapeutic strategies for NSCLC treatment. Mol Cancer Ther; 15(12); 3040–54. ©2016 AACR.
Data from Enhanced Oncolytic Activities of the Telomerase-Specific Replication-Competent Adenovirus Expressing Short-Hairpin RNA against Dicer
Authors: Machitani Mitsuhiro , Sakurai Fuminori , Wakabayashi Keisaku , Tachibana Masashi , Fujiwara Toshiyoshi , Mizuguchi Hiroyuki
Published: March 2024

Abstract
Oncolytic viruses have been receiving much attention as potential agents for cancer treatment. Among the various types of oncolytic viruses, the telomerase-specific replication-competent adenovirus (TRAD), which carries the tumor-specific promoter-driven E1 gene expression cassette, exhibits efficient antitumor effects. The development of a novel TRAD that shows higher replication efficiency and antitumor activity would be highly beneficial for safer and more efficient cancer therapy. We recently demonstrated that the endoribonuclease Dicer significantly inhibits the replication of wild-type adenovirus (Ad) via the processing of viral-associated (VA)-RNAs, which are Ad-encoded small noncoding RNAs, and that the knockdown of Dicer leads to enhanced VA-RNA expression and Ad replication after infection with wild-type Ad. Based on these findings, we herein developed a novel TRAD expressing short-hairpin RNA against Dicer (shDicer; TRAD-shDicer). After infection, TRAD-shDicer efficiently induced the knockdown of Dicer. TRAD-shDicer showed significantly higher replication efficiency and tumor cell lysis activity compared with the conventional TRAD in tumor cells. The Dicer expression levels and viabilities of normal cells were not altered by infection with TRAD-shDicer. These results indicate that TRAD-shDicer is a potent antitumor reagent by virtue of its enhanced oncolytic activity. Mol Cancer Ther; 16(1); 251–9. ©2016 AACR.
Data from Optimization of a PEGylated Glucuronide-Monomethylauristatin E Linker for Antibody–Drug Conjugates
Authors: Burke Patrick J. , Hamilton Joseph Z. , Jeffrey Scott C. , Hunter Joshua H. , Doronina Svetlana O. , Okeley Nicole M. , Miyamoto Jamie B. , Anderson Martha E. , Stone Ivan J. , Ulrich Michelle L. , Simmons Jessica K. , McKinney Erica E. , Senter Peter D. , Lyon Robert P.
Published: March 2024

Abstract
The emergence of antibody–drug conjugates (ADC), such as brentuximab vedotin and ado-trastuzumab emtansine, has led to increased efforts to identify new payloads and develop improved drug-linker technologies. Most antibody payloads impart significant hydrophobicity to the ADC, resulting in accelerated plasma clearance and suboptimal in vivo activity, particularly for conjugates with high drug-to-antibody ratios (DAR). We recently reported on the incorporation of a discrete PEG24 polymer as a side chain in a β-glucuronidase-cleavable monomethylauristatin E (MMAE) linker to provide homogeneous DAR 8 conjugates with decreased plasma clearance and increased antitumor activity in xenograft models relative to a non-PEGylated control. In this work, we optimized the drug-linker by minimizing the size of the PEG side chain and incorporating a self-stabilizing maleimide to prevent payload de-conjugation in vivo. Multiple PEG-glucuronide-MMAE linkers were prepared with PEG size up to 24 ethylene oxide units, and homogeneous DAR 8 ADCs were evaluated. A clear relationship was observed between PEG length and conjugate pharmacology when tested in vivo. Longer PEG chains resulted in slower clearance, with a threshold length of PEG8 beyond which clearance was not impacted. Conjugates bearing PEG of sufficient length to minimize plasma clearance provided a wider therapeutic window relative to faster clearing conjugates bearing shorter PEGs. A lead PEGylated glucuronide-MMAE linker was identified incorporating a self-stabilizing maleimide and a PEG12 side chain emerged from these efforts, enabling highly potent, homogeneous DAR 8 conjugates and is under consideration for future ADC programs. Mol Cancer Ther; 16(1); 116–23. ©2016 AACR.
Data from Mechanisms of Pinometostat (EPZ-5676) Treatment–Emergent Resistance in MLL-Rearranged Leukemia
Authors: Campbell Carly T. , Haladyna Jessica N. , Drubin David A. , Thomson Ty M. , Maria Michael J. , Yamauchi Taylor , Waters Nigel J. , Olhava Edward J. , Pollock Roy M. , Smith Jesse J. , Copeland Robert A. , Blakemore Stephen J. , Bernt Kathrin M. , Daigle Scott R.
Published: March 2024

Abstract
DOT1L is a protein methyltransferase involved in the development and maintenance of MLL-rearranged (MLL-r) leukemia through its ectopic methylation of histones associated with well-characterized leukemic genes. Pinometostat (EPZ-5676), a selective inhibitor of DOT1L, is in clinical development in relapsed/refractory acute leukemia patients harboring rearrangements of the MLL gene. The observation of responses and subsequent relapses in the adult trial treating MLL-r patients motivated preclinical investigations into potential mechanisms of pinometostat treatment-emergent resistance (TER) in cell lines confirmed to have MLL-r. TER was achieved in five MLL-r cell lines, KOPN-8, MOLM-13, MV4-11, NOMO-1, and SEM. Two of the cell lines, KOPN-8 and NOMO-1, were thoroughly characterized to understand the mechanisms involved in pinometostat resistance. Unlike many other targeted therapies, resistance does not appear to be achieved through drug-induced selection of mutations of the target itself. Instead, we identified both drug efflux transporter dependent and independent mechanisms of resistance to pinometostat. In KOPN-8 TER cells, increased expression of the drug efflux transporter ABCB1 (P-glycoprotein, MDR1) was the primary mechanism of drug resistance. In contrast, resistance in NOMO-1 cells occurs through a mechanism other than upregulation of a specific efflux pump. RNA-seq analysis performed on both parental and resistant KOPN-8 and NOMO-1 cell lines supported two unique candidate pathway mechanisms that may explain the pinometostat resistance observed in these cell lines. These results are the first demonstration of TER models of the DOT1L inhibitor pinometostat and may provide useful tools for investigating clinical resistance. Mol Cancer Ther; 16(8); 1669–79. ©2017 AACR.
Data from Characterization of In Vivo Resistance to Osimertinib and JNJ-61186372, an EGFR/Met Bispecific Antibody, Reveals Unique and Consensus Mechanisms of Resistance
Authors: Emdal Kristina B. , Dittmann Antje , Reddy Raven J. , Lescarbeau Rebecca S. , Moores Sheri L. , Laquerre Sylvie , White Forest M.
Published: March 2024

Abstract
Approximately 10% of non–small cell lung cancer (NSCLC) patients in the United States and 40% of NSCLC patients in Asia have activating epidermal growth factor receptor (EGFR) mutations and are eligible to receive targeted anti-EGFR therapy. Despite an extension of life expectancy associated with this treatment, resistance to EGFR tyrosine kinase inhibitors and anti-EGFR antibodies is almost inevitable. To identify additional signaling routes that can be cotargeted to overcome resistance, we quantified tumor-specific molecular changes that govern resistant cancer cell growth and survival. Mass spectrometry–based quantitative proteomics was used to profile in vivo signaling changes in 41 therapy-resistant tumors from four xenograft NSCLC models. We identified unique and tumor-specific tyrosine phosphorylation rewiring in tumors resistant to treatment with the irreversible third-generation EGFR-inhibitor, osimertinib, or the novel dual-targeting EGFR/Met antibody, JNJ-61186372. Tumor-specific increases in tyrosine-phosphorylated peptides from EGFR family members, Shc1 and Gab1 or Src family kinase (SFK) substrates were observed, underscoring a differential ability of tumors to uniquely escape EGFR inhibition. Although most resistant tumors within each treatment group displayed a marked inhibition of EGFR as well as SFK signaling, the combination of EGFR inhibition (osimertinib) and SFK inhibition (saracatinib or dasatinib) led to further decrease in cell growth in vitro. This result suggests that residual SFK signaling mediates therapeutic resistance and that elimination of this signal through combination therapy may delay onset of resistance. Overall, analysis of individual resistant tumors captured unique in vivo signaling rewiring that would have been masked by analysis of in vitro cell population averages. Mol Cancer Ther; 16(11); 2572–85. ©2017 AACR.
Data from PI3K Inhibitors Synergize with FGFR Inhibitors to Enhance Antitumor Responses in FGFR2mutant Endometrial Cancers
Authors: Packer Leisl M. , Geng Xinyan , Bonazzi Vanessa F. , Ju Robert J. , Mahon Clare E. , Cummings Margaret C. , Stephenson Sally-Anne , Pollock Pamela M.
Published: March 2024

Abstract
Improved therapeutic approaches are needed for the treatment of recurrent and metastatic endometrial cancer. Endometrial cancers display hyperactivation of the MAPK and PI3K pathways, the result of somatic aberrations in genes such as FGFR2, KRAS, PTEN, PIK3CA, and PIK3R1. The FGFR2 and PI3K pathways, have emerged as potential therapeutic targets in endometrial cancer. Activation of the PI3K pathway is seen in more than 90% of FGFR2mutant endometrial cancers. This study aimed to examine the efficacy of the pan-FGFR inhibitor BGJ398 with pan-PI3K inhibitors (GDC-0941, BKM120) and the p110α-selective inhibitor BYL719. We assessed synergy in three FGFR2mutant endometrial cancer cell lines (AN3CA, JHUEM2, and MFE296), and the combination of BGJ398 and GDC-0941 or BYL719 showed strong synergy. A significant increase in cell death and decrease in long-term survival was seen when PI3K inhibitors were combined with BGJ398. Importantly, these effects were seen at low concentrations correlating to only partial inhibition of AKT. The combination of BGJ398 and GDC-0941 showed tumor regressions in vivo, whereas each drug alone only showed moderate tumor growth inhibition. BYL719 alone resulted in increased tumor growth of AN3CA xenografts but in combination with BGJ398 resulted in tumor regression in both AN3CA- and JHUEM2-derived xenografts. These data provide evidence that subtherapeutic doses of PI3K inhibitors enhance the efficacy of anti-FGFR therapies, and a combination therapy may represent a superior therapeutic treatment in patients with FGFR2mutant endometrial cancer. Mol Cancer Ther; 16(4); 637–48. ©2017 AACR.
Data from Cell-Cycle Gene Alterations in 4,864 Tumors Analyzed by Next-Generation Sequencing: Implications for Targeted Therapeutics
Authors: Helsten Teresa , Kato Shumei , Schwaederle Maria , Tomson Brett N. , Buys Timon P.H. , Elkin Sheryl K. , Carter Jennifer L. , Kurzrock Razelle
Published: March 2024

Abstract
Alterations in the cyclin-dependent kinase (CDK)-retinoblastoma (RB) machinery disrupt cell-cycle regulation and are being targeted in drug development. To understand the cancer types impacted by this pathway, we analyzed frequency of abnormalities in key cell-cycle genes across 4,864 tumors using next-generation sequencing (182 or 236 genes; Clinical Laboratory Improvement Amendments laboratory). Aberrations in the cell-cycle pathway were identified in 39% of cancers, making this pathway one of the most commonly altered in cancer. The frequency of aberrations was as follows: CDKN2A/B (20.1% of all patients), RB1 (7.6%), CCND1 (6.1%), CCNE1 (3.6%), CDK4 (3.2%), CCND3 (1.8%), CCND2 (1.7%), and CDK6 (1.7%). Rates and types of aberrant cell-cycle pathway genes differed between cancer types and within histologies. Analysis of coexisting and mutually exclusive genetic aberrations showed that CCND1, CCND2, and CCND3 aberrations were all positively associated with CDK6 aberrations [OR and P values, multivariate analysis: CCND1 and CDK6 (OR = 3.5; P < 0.0001), CCND2 and CDK6 (OR = 4.3; P = 0.003), CCND3 and CDK6 (OR = 3.6; P = 0.007)]. In contrast, RB1 alterations were negatively associated with multiple gene anomalies in the cell-cycle pathway, including CCND1 (OR = 0.25; P = 0.003), CKD4 (OR = 0.10; P = 0.001), and CDKN2A/B (OR = 0.21; P < 0.0001). In conclusion, aberrations in the cell-cycle pathway were very common in diverse cancers (39% of 4,864 neoplasms). The frequencies and types of alterations differed between and within tumor types and will be informative for drug development strategies. Mol Cancer Ther; 15(7); 1682–90. ©2016 AACR.
Data from ATM Expression Predicts Veliparib and Irinotecan Sensitivity in Gastric Cancer by Mediating P53-Independent Regulation of Cell Cycle and Apoptosis
Authors: Subhash Vinod Vijay , Tan Shi Hui , Yeo Mei Shi , Yan Fui Leng , Peethala Praveen C. , Liem Natalia , Krishnan Vaidehi , Yong Wei Peng
Published: March 2024

Abstract
Identification of synthetically lethal cellular targets and synergistic drug combinations is important in cancer chemotherapy as they help to overcome treatment resistance and increase efficacy. The Ataxia Telangiectasia Mutated (ATM) kinase is a nuclear protein that plays a major role in the initiation of DNA repair signaling and cell-cycle check points during DNA damage. Although ATM was shown to be associated with poor prognosis in gastric cancer, its implications as a predictive biomarker for cancer chemotherapy remain unexplored. The present study evaluated ATM-induced synthetic lethality and its role in sensitization of gastric cancer cells to PARP and TOP1 inhibitors, veliparib (ABT-888) and irinotecan (CPT-11), respectively. ATM expression was detected in a panel of gastric cell lines, and the IC50 against each inhibitors was determined. The combinatorial effect of ABT-888 and CPT-11 in gastric cancer cells was also determined both in vitro and in vivo. ATM deficiency was found to be associated with enhanced sensitivity to ABT-888 and CPT-11 monotherapy, hence suggesting a mechanism of synthetic lethality. Cells with high ATM expression showed reduced sensitivity to monotherapy; however, they showed a higher therapeutic effect with ABT-888 and CPT-11 combinatorial therapy. Furthermore, ATM expression was shown to play a major role in cellular homeostasis by regulating cell-cycle progression and apoptosis in a P53-independent manner. The present study highlights the clinical utility of ATM expression as a predictive marker for sensitivity of gastric cancer cells to PARP and TOP1 inhibition and provides a deeper mechanistic insight into ATM-dependent regulation of cellular processes. Mol Cancer Ther; 15(12); 3087–96. ©2016 AACR.
Data from Tumor-targeted Nanoparticle Delivery of HuR siRNA Inhibits Lung Tumor Growth In Vitro and In Vivo By Disrupting the Oncogenic Activity of the RNA-binding Protein HuR
Authors: Muralidharan Ranganayaki , Babu Anish , Amreddy Narsireddy , Srivastava Akhil , Chen Allshine , Zhao Yan Daniel , Kompella Uday B. , Munshi Anupama , Ramesh Rajagopal
Published: March 2024

Abstract
Selective downregulation of the human antigen R (HuR) protein by siRNA may provide a powerful approach for treating lung cancer. To this end, we investigated the efficacy of transferrin receptor-targeted liposomal nanoparticle-based HuR siRNA (HuR-TfNP) therapy and compared with control siRNA (C)-TfNP therapy both, in vitro and in vivo using lung cancer models. In vitro studies showed HuR-TfNP, but not C-TfNP, efficiently downregulated HuR and HuR-regulated proteins in A549, and HCC827 lung cancer cells, resulting in reduced cell viability, inhibition of cell migration and invasion, and induction of G1 cell-cycle arrest culminating in apoptosis. However, HuR-TfNP activity in normal MRC-9 lung fibroblasts was negligible. In vivo biodistribution study demonstrated that fluorescently labeled HuR-siRNA or ICG dye–loaded TfNP localized in tumor tissues. Efficacy studies showed intratumoral or intravenous administration of HuR-TfNP significantly inhibited A549 (>55% inhibition) and HCC827 (>45% inhibition) subcutaneous tumor growth compared with C-TfNP. Furthermore, HuR-TfNP treatment reduced HuR, Ki67, and CD31 expression and increased caspase-9 and PARP cleavage and TUNEL-positive staining indicative of apoptotic cell death in tumor tissues compared with C-TfNP treatment. The antitumor activity of HuR-TfNP was also observed in an A549-luc lung metastatic model, as significantly fewer tumor nodules (9.5 ± 3.1; P < 0.001; 88% inhibition) were observed in HuR-TfNP–treated group compared with the C-TfNP–treated group (77.7 ± 20.1). Significant reduction in HuR, Ki67, and CD31 expression was also observed in the tumor tissues of HuR-TfNP-treatment compared with C-TfNP treatment. Our findings highlight HuR-TfNP as a promising nanotherapeutic system for lung cancer treatment. Mol Cancer Ther; 16(8); 1470–86. ©2017 AACR.
Data from Photodynamic Therapy Using Photosensitizer-Encapsulated Polymeric Nanoparticle to Overcome ATP-Binding Cassette Transporter Subfamily G2 Function in Pancreatic Cancer
Authors: Roh Yoon Jin , Kim Ju Hee , Kim In-Wook , Na Kun , Park Jae Myung , Choi Myung-Gyu
Published: March 2024

Abstract
Chlorin-based photosensitizers are commonly used in photodynamic therapy (PDT). These drugs are effluxed by cell membrane transporters, such as the ATP-binding cassette subfamily G member 2 (ABCG2). PDT efficacy is limited in tumor cells expressing high levels of these proteins. Pancreatic cancer cell lines AsPC-1 and MIA PaCa-2, which have high and low ABCG2 expression, respectively, were used, and ABCG2-overexpressing MIA PaCa-2 cells were generated. We compared PDT efficacy between chlorin e6 (Ce6) and cationic photosensitizer–encapsulated polymeric nanoparticle (PS-pNP), which is comprised with Ce6, polyethylene glycol, and polyethylenimine. The intracellular concentration of Ce6 was significantly higher in MIA PaCa-2 cells than in AsPC-1 or ABCG2-overexpressing MIA PaCa-2 cells. PS-pNP increased intracellular levels of the photosensitizer in all cell lines. The cell viability experiments indicated increased Ce6 resistance in ABCG2-overexpressing cells. In contrast, PS-pNP produced similar levels of cytotoxicity in each of the cancer cell lines tested. Singlet oxygen production was higher in cells treated with PS-pNP than in those treated with Ce6. Furthermore, in heterotopic and orthotopic AsPC-1 xenograft mouse models, PDT using PS-pNP significantly reduced tumor volume in comparison with that of Ce6 treatment. PS-pNP could increase intracellular Ce6 concentration, which was related with reduced ABCG2-mediated efflux of Ce6, thereby enhancing the effects of PDT in pancreatic cancer cells. Mol Cancer Ther; 16(8); 1487–96. ©2017 AACR.
Data from Inactivation of the Kinase Domain of CDK10 Prevents Tumor Growth in a Preclinical Model of Colorectal Cancer, and Is Accompanied by Downregulation of Bcl-2
Authors: Weiswald Louis-Bastien , Hasan Mohammad R. , Wong John C.T. , Pasiliao Clarissa C. , Rahman Mahbuba , Ren Jianhua , Yin Yaling , Gusscott Samuel , Vacher Sophie , Weng Andrew P. , Kennecke Hagen F. , Bièche Ivan , Schaeffer David F. , Yapp Donald T. , Tai Isabella T.
Published: March 2024

Abstract
Cyclin-dependent kinase 10 (CDK10), a CDC2-related kinase, is highly expressed in colorectal cancer. Its role in the pathogenesis of colorectal cancer is unknown. This study examines the function of CDK10 in colorectal cancer, and demonstrates its role in suppressing apoptosis and in promoting tumor growth in vitro and in vivo. Modulation of CDK10 expression in colorectal cancer cell lines demonstrates that CDK10 promotes cell growth, reduces chemosensitivity and inhibits apoptosis by upregulating the expression of Bcl-2. This effect appears to depend on its kinase activity, as kinase-defective mutant colorectal cancer cell lines have an exaggerated apoptotic response and reduced proliferative capacity. In vivo, inhibiting CDK10 in colorectal cancer following intratumoral injections of lentivirus-mediated CDK10 siRNA in a patient-derived xenograft mouse model demonstrated its efficacy in suppressing tumor growth. Furthermore, using a tissue microarray of human colorectal cancer tissues, the potential for CDK10 to be a prognostic biomarker in colorectal cancer was explored. In tumors of individuals with colorectal cancer, high expression of CDK10 correlates with earlier relapse and shorter overall survival. The findings of this study indicate that CDK10 plays a role in the pathogenesis in colorectal cancer and may be a potential therapeutic target for treatment. Mol Cancer Ther; 16(10); 2292–303. ©2017 AACR.
Data from Pharmacological Inhibition of the Protein Kinase MRK/ZAK Radiosensitizes Medulloblastoma
Authors: Markowitz Daniel , Powell Caitlin , Tran Nhan L. , Berens Michael E. , Ryken Timothy C. , Vanan Magimairajan , Rosen Lisa , He Mingzhu , Sun Shan , Symons Marc , Al-Abed Yousef , Ruggieri Rosamaria
Published: March 2024

Abstract
Medulloblastoma is a cerebellar tumor and the most common pediatric brain malignancy. Radiotherapy is part of the standard care for this tumor, but its effectiveness is accompanied by significant neurocognitive sequelae due to the deleterious effects of radiation on the developing brain. We have previously shown that the protein kinase MRK/ZAK protects tumor cells from radiation-induced cell death by regulating cell-cycle arrest after ionizing radiation. Here, we show that siRNA-mediated MRK depletion sensitizes medulloblastoma primary cells to radiation. We have, therefore, designed and tested a specific small molecule inhibitor of MRK, M443, which binds to MRK in an irreversible fashion and inhibits its activity. We found that M443 strongly radiosensitizes UW228 medulloblastoma cells as well as UI226 patient–derived primary cells, whereas it does not affect the response to radiation of normal brain cells. M443 also inhibits radiation-induced activation of both p38 and Chk2, two proteins that act downstream of MRK and are involved in DNA damage–induced cell-cycle arrest. Importantly, in an animal model of medulloblastoma that employs orthotopic implantation of primary patient–derived UI226 cells in nude mice, M443 in combination with radiation achieved a synergistic increase in survival. We hypothesize that combining radiotherapy with M443 will allow us to lower the radiation dose while maintaining therapeutic efficacy, thereby minimizing radiation-induced side effects. Mol Cancer Ther; 15(8); 1799–808. ©2016 AACR.
Data from Establishment of the In Vivo Efficacy of Pretargeted Radioimmunotherapy Utilizing Inverse Electron Demand Diels-Alder Click Chemistry
Authors: Houghton Jacob L. , Membreno Rosemery , Abdel-Atti Dalya , Cunanan Kristen M. , Carlin Sean , Scholz Wolfgang W. , Zanzonico Pat B. , Lewis Jason S. , Zeglis Brian M.
Published: March 2024

Abstract
The pretargeting system based on the inverse electron demand Diels-Alder reaction (IEDDA) between trans-cyclooctene (TCO) and tetrazine (Tz) combines the favorable pharmacokinetic properties of radiolabeled small molecules with the affinity and specificity of antibodies. This strategy has proven to be an efficient method for the molecularly targeted delivery of pharmaceuticals, including isotopes for radiological imaging. Despite encouraging results from in vivo PET imaging studies, this promising system has yet to be thoroughly evaluated for pretargeted radioimmunotherapy (PRIT). Toward that end, we synthesized two novel 177Lu-labeled tetrazine-bearing radioligands. Next, we compared the usefulness of our ligands for PRIT when paired with TCO-modified 5B1—a human, anti-CA19.9 mAb—in preclinical murine models of pancreatic cancer. The exemplary ligand, 177Lu-DOTA-PEG7-Tz, showed rapid (4.6 ± 0.8% ID/g at 4 hours) and persistent (16.8 ± 3.9% ID/g at 120 hours) uptake in tumors while concurrently clearing from blood and nontarget tissues. Single-dose therapy studies using 5B1-TCO and varying amounts of 177Lu-DOTA-PEG7-Tz (400, 800, and 1,200 μCi) showed that our system elicits a dose-dependent therapeutic response in mice bearing human xenografts. Furthermore, dosimetry calculations suggest that our approach is amenable to clinical applications with its excellent dosimetric profile in organs of clearance (i.e., liver and kidneys) as well as in dose-limiting tissues, such as red marrow. This study established that a pretargeted methodology utilizing the IEDDA reaction can rapidly and specifically deliver a radiotherapeutic payload to tumor tissue, thus illustrating its excellent potential for clinical translation. Mol Cancer Ther; 16(1); 124–33. ©2016 AACR.
Data from Synthesis and Profiling of a Novel Potent Selective Inhibitor of CHK1 Kinase Possessing Unusual N-trifluoromethylpyrazole Pharmacophore Resistant to Metabolic N-dealkylation
Authors: Samadder Pounami , Suchánková Tereza , Hylse Ondřej , Khirsariya Prashant , Nikulenkov Fedor , Drápela Stanislav , Straková Nicol , Vaňhara Petr , Vašíčková Kateřina , Kolářová Hana , Binó Lucia , Bittová Miroslava , Ovesná Petra , Kollár Peter , Fedr Radek , Ešner Milan , Jaroš Josef , Hampl Aleš , Krejčí Lumír , Paruch Kamil , Souček Karel
Published: March 2024

Abstract
Checkpoint-mediated dependency of tumor cells can be deployed to selectively kill them without substantial toxicity to normal cells. Specifically, loss of CHK1, a serine threonine kinase involved in the surveillance of the G2–M checkpoint in the presence of replication stress inflicted by DNA-damaging drugs, has been reported to dramatically influence the viability of tumor cells. CHK1′s pivotal role in maintaining genomic stability offers attractive opportunity for increasing the selectivity, effectivity, and reduced toxicity of chemotherapy. Some recently identified CHK1 inhibitors entered clinical trials in combination with DNA antimetabolites. Herein, we report synthesis and profiling of MU380, a nontrivial analogue of clinically profiled compound SCH900776 possessing the highly unusual N-trifluoromethylpyrazole motif, which was envisioned not to undergo metabolic oxidative dealkylation and thereby provide greater robustness to the compound. MU380 is a selective and potent inhibitor of CHK1 which sensitizes a variety of tumor cell lines to hydroxyurea or gemcitabine up to 10 times. MU380 shows extended inhibitory effects in cells, and unlike SCH900776, does not undergo in vivo N-dealkylation to the significantly less selective metabolite. Compared with SCH900776, MU380 in combination with GEM causes higher accumulation of DNA damage in tumor cells and subsequent enhanced cell death, and is more efficacious in the A2780 xenograft mouse model. Overall, MU380 represents a novel state-of-the-art CHK1 inhibitor with high potency, selectivity, and improved metabolic robustness to oxidative N-dealkylation. Mol Cancer Ther; 16(9); 1831–42. ©2017 AACR.
Data from Activating Transcription Factor 3 Expression as a Marker of Response to the Histone Deacetylase Inhibitor Pracinostat
Authors: Sooraj Dhanya , Xu Dakang , Cain Jason E. , Gold Daniel P. , Williams Bryan R.G.
Published: March 2024

Abstract
Improved treatment strategies are required for bladder cancer due to frequent recurrence of low-grade tumors and poor survival rate from high-grade tumors with current therapies. Histone deacetylase inhibitors (HDACi), approved as single agents for specific lymphomas, have shown promising preclinical results in solid tumors but could benefit from identification of biomarkers for response. Loss of activating transcription factor 3 (ATF3) expression is a feature of bladder tumor progression and correlates with poor survival. We investigated the utility of measuring ATF3 expression as a marker of response to the HDACi pracinostat in bladder cancer models. Pracinostat treatment of bladder cancer cell lines reactivated the expression of ATF3, correlating with significant alteration in proliferative, migratory, and anchorage-dependent growth capacities. Pracinostat also induced growth arrest at the G0–G1 cell-cycle phase, coincident with the activation of tumor suppressor genes. In mouse xenograft bladder cancer models, pracinostat treatment significantly reduced tumor volumes compared with controls, accompanied by reexpression of ATF3 in nonproliferating cells from early to late stage of therapy and in parallel induced antiangiogenesis and apoptosis. Importantly, cells in which ATF3 expression was depleted were less sensitive to pracinostat treatment in vitro, exhibiting significantly higher proliferative and migratory properties. In vivo, control xenograft tumors were significantly more responsive to treatment than ATF3 knockdown xenografts. Thus, reactivation of ATF3 is an important factor in determining sensitivity to pracinostat treatment, both in vitro and in vivo, and could serve as a potential biomarker of response and provide a rationale for therapeutic utility in HDACi-mediated treatments for bladder cancer. Mol Cancer Ther; 15(7); 1726–39. ©2016 AACR.
Data from Identification of the Serine Biosynthesis Pathway as a Critical Component of BRAF Inhibitor Resistance of Melanoma, Pancreatic, and Non–Small Cell Lung Cancer Cells
Authors: Ross Kayleigh C. , Andrews Andrew J. , Marion Christopher D. , Yen Timothy J. , Bhattacharjee Vikram
Published: March 2024

Abstract
Metastatic melanoma cells commonly acquire resistance to BRAF V600E inhibitors (BRAFi). In this study, we identified serine biosynthesis as a critical mechanism of resistance. Proteomic assays revealed differential protein expression of serine biosynthetic enzymes PHGDH, PSPH, and PSAT1 following vemurafenib (BRAFi) treatment in sensitive versus acquired resistant melanoma cells. Ablation of PHGDH via siRNA sensitized acquired resistant cells to vemurafenib. Inhibiting the folate cycle, directly downstream of serine synthesis, with methotrexate also displayed similar sensitization. Using the DNA-damaging drug gemcitabine, we show that gemcitabine pretreatment sensitized resistant melanoma cells to BRAFis vemurafenib and dabrafenib. We extended our findings to BRAF WT tumor cell lines that are intrinsically resistant to vemurafenib and dabrafenib. Pretreatment of pancreatic cancer and non–small cell lung cancer cell lines with sublethal doses of 50 and 5 nmol/L of gemcitabine, respectively, enhanced killing by both vemurafenib and dabrafenib. The novel aspects of this study are the direct identification of serine biosynthesis as a critical mechanism of BRAF V600E inhibitor resistance and the first successful example of using gemcitabine + BRAFis in combination to kill previously drug-resistant cancer cells, creating the translational potential of pretreatment with gemcitabine prior to BRAFi treatment of tumor cells to reverse resistance within the mutational profile and the WT. Mol Cancer Ther; 16(8); 1596–609. ©2017 AACR.
Data from Herpes Simplex Virus Glycoprotein D Targets a Specific Dendritic Cell Subset and Improves the Performance of Vaccines to Human Papillomavirus-Associated Tumors
Authors: Porchia Bruna F.M.M. , Moreno Ana Carolina R. , Ramos Rodrigo N. , Diniz Mariana O. , de Andrade Laís Helena T.M. , Rosa Daniela S. , Barbuto José Alexandre M. , Boscardin Silvia B. , Ferreira Luís Carlos S.
Published: March 2024

Abstract
Cervical cancer is a major public health problem and one of the leading causes of cancer deaths in women. Virtually all cases of cervical cancer, as well as a growing share of anal and head/neck tumors, are associated with human papillomavirus (HPV) infection. Despite the effectiveness, the available prophylactic vaccines do not benefit women with cervical lesions or cancer. Therefore, the search of new immunotherapeutic approaches to treat HPV-induced tumors is still a priority. The present study characterizes a therapeutic antitumor vaccine based on the genetic fusion of the Herpes simplex virus-1 (HSV-1) glycoprotein D (gD) with the E7 oncoprotein from HPV-16 (gDE7). Two subcutaneous doses of gDE7, admixed with poly (I:C), conferred complete and long-lasting therapeutic antitumor protection on mice previously challenged with tumor cells expressing the HPV-16 oncoproteins. The vaccine induced multifunctional E7-specific CD8+ T cells with cytotoxic activity and effector memory phenotype (CD44+ CD62Llow). In addition, gDE7 admixed with poly (I:C) vaccination controlled the expansion of tumor-induced regulatory T cells and myeloid-derived suppressor cells. More importantly, gDE7 activated mouse CD11c+ CD8α+ and human BDCA3+ dendritic cells (DC), specialized in antigen cross-presentation to CD8+ T cells, under in vitro conditions. These results indicated that the activation of a specific DC population, mediated by gD, improved the antigen-specific immune responses and the therapeutic performance induced by antitumor vaccines. These results open perspectives for the clinical testing of gDE7-based vaccines under the concept of active immunization as a tool for the therapeutic control of cancer. Mol Cancer Ther; 16(9); 1922–33. ©2017 AACR.
Data from KITlow Cells Mediate Imatinib Resistance in Gastrointestinal Stromal Tumor
Authors: Banerjee Sudeep , Yoon Hyunho , Ting Stephanie , Tang Chih-Min , Yebra Mayra , Wenzel Alexander T. , Yeerna Huwate , Mesirov Jill P. , Wechsler-Reya Robert J. , Tamayo Pablo , Sicklick Jason K.
Published: March 2024

Abstract
Gastrointestinal stromal tumor (GIST) is commonly driven by oncogenic KIT mutations that are effectively targeted by imatinib (IM), a tyrosine kinase inhibitor (TKI). However, IM does not cure GIST, and adjuvant therapy only delays recurrence in high-risk tumors. We hypothesized that GIST contains cells with primary IM resistance that may represent a reservoir for disease persistence. Here, we report a subpopulation of CD34+KITlow human GIST cells that have intrinsic IM resistance. These cells possess cancer stem cell-like expression profiles and behavior, including self-renewal and differentiation into CD34+KIThigh progeny that are sensitive to IM treatment. We also found that TKI treatment of GIST cell lines led to induction of stem cell–associated transcription factors (OCT4 and NANOG) and concomitant enrichment of the CD34+KITlow cell population. Using a data-driven approach, we constructed a transcriptomic-oncogenic map (Onco-GPS) based on the gene expression of 134 GIST samples to define pathway activation during GIST tumorigenesis. Tumors with low KIT expression had overexpression of cancer stem cell gene signatures consistent with our in vitro findings. Additionally, these tumors had activation of the Gas6/AXL pathway and NF-κB signaling gene signatures. We evaluated these targets in vitro and found that primary IM-resistant GIST cells were effectively targeted with either single-agent bemcentinib (AXL inhibitor) or bardoxolone (NF-κB inhibitor), as well as with either agent in combination with IM. Collectively, these findings suggest that CD34+KITlow cells represent a distinct, but targetable, subpopulation in human GIST that may represent a novel mechanism of primary TKI resistance, as well as a target for overcoming disease persistence following TKI therapy.
Data from Tankyrase Inhibitors Target Colorectal Cancer Stem Cells via AXIN-Dependent Downregulation of c-KIT Tyrosine Kinase
Authors: Jang Myung-Kyu , Mashima Tetsuo , Seimiya Hiroyuki
Published: March 2024

Abstract
Cancer stem cells (CSC) constitute heterogeneous cell subpopulations of a tumor. Although targeting CSCs is important for cancer eradication, no clinically approved drugs that target CSCs have been established. Tankyrase poly(ADP-ribosyl)ates and destabilizes AXIN, a negative regulator of β-catenin, and promotes β-catenin signaling. Here, we report that tankyrase inhibitors downregulate c-KIT tyrosine kinase and inhibit the growth of CD44-positive colorectal CSCs. c-KIT expression in CD44-positive subpopulations of colorectal cancer COLO-320DM cells is associated with their tumor-initiating potential in vivo. Tankyrase inhibitors downregulate c-KIT expression in established cell lines, such as COLO-320DM and DLD-1, and colorectal cancer patient–derived cells. These effects of tankyrase inhibitors are caused by reducing the recruitment of SP1 transcription factor to the c-KIT gene promoter and depend on AXIN2 stabilization but not β-catenin downregulation. Whereas c-KIT knockdown inhibits the growth of CD44-positive COLO-320DM cells, c-KIT overexpression in DLD-1 cells confers resistance to tankyrase inhibitors. Combination of a low-dose tankyrase inhibitor and irinotecan significantly inhibited the growth of COLO-320DM tumors in a mouse xenograft model. These observations suggest that tankyrase inhibitors target c-KIT–positive colorectal CSCs and provide a novel therapeutic strategy for cancer.
Data from Translational Strategies for Repotrectinib in Neuroblastoma
Authors: O'Donohue Tara J. , Ibáñez Glorymar , Coutinho Diego Ferreira , Mauguen Audrey , Siddiquee Armaan , Rosales Nestor , Calder Paul , Ndengu Andoyo , You Daoqi , Long Matthew , Roberts Stephen S. , Kung Andrew L. , Dela Cruz Filemon S.
Published: March 2024

Abstract
Limited clinical data are available regarding the utility of multikinase inhibition in neuroblastoma. Repotrectinib (TPX-0005) is a multikinase inhibitor that targets ALK, TRK, JAK2/STAT, and Src/FAK, which have all been implicated in the pathogenesis of neuroblastoma. We evaluated the preclinical activity of repotrectinib monotherapy and in combination with chemotherapy as a potential therapeutic approach for relapsed/refractory neuroblastoma. In vitro sensitivity to repotrectinib, ensartinib, and cytotoxic chemotherapy was evaluated in neuroblastoma cell lines. In vivo antitumor effect of repotrectinib monotherapy, and in combination with chemotherapy, was evaluated using a genotypically diverse cohort of patient-derived xenograft (PDX) models of neuroblastoma. Repotrectinib had comparable cytotoxic activity across cell lines irrespective of ALK mutational status. Combination with chemotherapy demonstrated increased antiproliferative activity across several cell lines. Repotrectinib monotherapy had notable antitumor activity and prolonged event-free survival compared with vehicle and ensartinib in PDX models (P < 0.05). Repotrectinib plus chemotherapy was superior to chemotherapy alone in ALK-mutant and ALK wild-type PDX models. These results demonstrate that repotrectinib has antitumor activity in genotypically diverse neuroblastoma models, and that combination of a multikinase inhibitor with chemotherapy may be a promising treatment paradigm for translation to the clinic.