bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from DCDT2980S, an Anti-CD22-Monomethyl Auristatin E Antibody–Drug Conjugate, Is a Potential Treatment for Non-Hodgkin Lymphoma
Authors: Li Dongwei , Poon Kirsten Achilles , Yu Shang-Fan , Dere Randall , Go MaryAnn , Lau Jeffrey , Zheng Bing , Elkins Kristi , Danilenko Dimitry , Kozak Katherine R. , Chan Pamela , Chuh Josefa , Shi Xiaoyan , Nazzal Denise , Fuh Franklin , McBride Jacqueline , Ramakrishnan Vanitha , de Tute Ruth , Rawstron Andy , Jack Andrew S. , Deng Rong , Chu Yu-Waye , Dornan David , Williams Marna , Ho William , Ebens Allen , Prabhu Saileta , Polson Andrew G.
Published: March 2024

Abstract
Antibody–drug conjugates (ADC), potent cytotoxic drugs linked to antibodies via chemical linkers, allow specific targeting of drugs to neoplastic cells. We have used this technology to develop the ADC DCDT2980S that targets CD22, an antigen with expression limited to B cells and the vast majority of non-Hodgkin lymphomas (NHL). DCDT2980S consists of a humanized anti-CD22 monoclonal IgG1 antibody with a potent microtubule-disrupting agent, monomethyl auristatin E (MMAE), linked to the reduced cysteines of the antibody via a protease cleavable linker, maleimidocaproyl-valine-citrulline-p-aminobenzoyloxycarbonyl (MC-vc-PAB). We describe the efficacy, safety, and pharmacokinetics of DCDT2980S in animal models to assess its potential as a therapeutic for the treatment of B-cell malignancies. We did not find a strong correlation between in vitro or in vivo efficacy and CD22 surface expression, nor a correlation of sensitivity to free drug and in vitro potency. We show that DCDT2980S was capable of inducing complete tumor regression in xenograft mouse models of NHL and can be more effective than rituximab plus combination chemotherapy at drug exposures that were well tolerated in cynomolgus monkeys. These results suggest that DCDT2980S has an efficacy, safety, and pharmacokinetics profile that support potential treatment of NHL. Mol Cancer Ther; 12(7); 1255–65. ©2013 AACR.
Data from AZD3514: A Small Molecule That Modulates Androgen Receptor Signaling and Function In Vitro and In Vivo
Authors: Loddick Sarah A. , Ross Sarah J. , Thomason Andrew G. , Robinson David M. , Walker Graeme E. , Dunkley Tom P.J. , Brave Sandra R. , Broadbent Nicola , Stratton Natalie C. , Trueman Dawn , Mouchet Elizabeth , Shaheen Fadhel S. , Jacobs Vivien N. , Cumberbatch Marie , Wilson Joanne , Jones Rhys D.O. , Bradbury Robert H. , Rabow Alfred , Gaughan Luke , Womack Chris , Barry Simon T. , Robson Craig N. , Critchlow Susan E. , Wedge Stephen R. , Brooks A. Nigel
Published: March 2024

Abstract
Continued androgen receptor (AR) expression and signaling is a key driver in castration-resistant prostate cancer (CRPC) after classical androgen ablation therapies have failed, and therefore remains a target for the treatment of progressive disease. Here, we describe the biological characterization of AZD3514, an orally bioavailable drug that inhibits androgen-dependent and -independent AR signaling. AZD3514 modulates AR signaling through two distinct mechanisms, an inhibition of ligand-driven nuclear translocation of AR and a downregulation of receptor levels, both of which were observed in vitro and in vivo. AZD3514 inhibited testosterone-driven seminal vesicle development in juvenile male rats and the growth of androgen-dependent Dunning R3327H prostate tumors in adult rats. Furthermore, this class of compound showed antitumor activity in the HID28 mouse model of CRPC in vivo. AZD3514 is currently in phase I clinical evaluation. Mol Cancer Ther; 12(9); 1715–27. ©2013 AACR.
Data from miRNA-141, Downregulated in Pancreatic Cancer, Inhibits Cell Proliferation and Invasion by Directly Targeting MAP4K4
Authors: Zhao Gang , Wang Bo , Liu Yang , Zhang Jun-gang , Deng Shi-chang , Qin Qi , Tian Kui , Li Xiang , Zhu Shuai , Niu Yi , Gong Qiong , Wang Chun-you
Published: March 2024

Abstract
miRNAs are associated with various types of cancer due to their ability to affect expression of genes that modulate tumorigenesis. In this study, we explored the role of miR-141 in pancreatic cancer. The analysis of clinical characteristics showed that miR-141 was significantly downregulated in tissues and cell lines of pancreatic cancer. Moreover, the decreased miR-141 level was significantly associated with tumor size and TNM stage, as well as lymph node and distant metastasis. Meanwhile, both Kaplan–Meier and multivariate survival analysis showed decreased miR-141 were associated with overall survival. Overexpression of miR-141 in pancreatic cancer cells inhibited cell proliferation, clonogenicity, and invasion; induced G1 arrest and apoptosis; and enhanced chemosensitivity. To understand how miR-141 mediates the phenotype of pancreatic cancer cells, a bioinformatics tool was used to identify MAP4K4 as a potential target of miR-141. The Dual-Luciferase reporter gene assay showed that miR-141 binds directly to the 3′-untranslated region (3′UTR) of MAP4K4 to inhibit MAP4K4 expression. Western blot and quantitative real-time PCR (qRT-PCR) analyses revealed that MAP4K4 expression was inversely correlated with miR-141 expression both in pancreatic cancer samples and cell lines. Knockdown of MAP4K4 inhibited cell proliferation, clonogenicity, and invasion, induced G1 arrest and apoptosis, and enhanced chemosensitivity. In a nude mouse xenograft model, both overexpression of miR-141 and knockdown of MAP4K4 significantly repressed pancreatic cancer cell growth. Therefore, we conclude that miR-141 targets MAP4K4, acts as a tumor suppressor in pancreatic cancer cells, and may serve as a novel therapeutic agent for miRNA-based pancreatic cancer therapy. Mol Cancer Ther; 12(11); 2569–80. ©2013 AACR.
Data from Potential Role of mTORC2 as a Therapeutic Target in Clear Cell Carcinoma of the Ovary
Authors: Hisamatsu Takeshi , Mabuchi Seiji , Matsumoto Yuri , Kawano Mahiru , Sasano Tomoyuki , Takahashi Ryoko , Sawada Kenjiro , Ito Kimihiko , Kurachi Hirohisa , Schilder Russell J. , Testa Joseph R. , Kimura Tadashi
Published: March 2024

Abstract
The goal of this study was to examine the role of mTOR complex 2 (mTORC2) as a therapeutic target in ovarian clear cell carcinoma (CCC), which is regarded as an aggressive, chemoresistant histologic subtype. Using tissue microarrays of 98 primary ovarian cancers [52 CCCs and 46 serous adenocarcinomas (SAC)], activation of mTORC2 was assessed by immunohistochemistry. Then, the growth-inhibitory effect of mTORC2-targeting therapy, as well as the role of mTORC2 signaling as a mechanism for acquired resistance to the mTOR complex 1 (mTORC1) inhibitor RAD001 in ovarian CCC, were examined using two pairs of RAD001-sensitive parental (RMG2 and HAC2) and RAD001-resistant CCC cell lines (RMG2-RR and HAC2-RR). mTORC2 was more frequently activated in CCCs than in SACs (71.2% vs. 45.7%). Simultaneous inhibition of mTORC1 and mTORC2 by AZD8055 markedly inhibited the proliferation of both RAD001-sensitive and -resistant cells in vitro. Treatment with RAD001 induced mTORC2-mediated AKT activation in RAD001-sensitive CCC cells. Moreover, increased activation of mTORC2–AKT signaling was observed in RAD001-resistant CCC cells compared with the respective parental cells. Inhibition of mTORC2 during RAD001 treatment enhanced the antitumor effect of RAD001 and prevented CCC cells from acquiring resistance to RAD001. In conclusion, mTORC2 is frequently activated, and can be a promising therapeutic target, in ovarian CCCs. Moreover, mTORC2-targeted therapy may be efficacious in a first-line setting as well as for second-line treatment of recurrent disease developing after RAD001-treatment. Mol Cancer Ther; 12(7); 1367–77. ©2013 AACR.
Data from Chemotherapy-Regulated microRNA-125–HER2 Pathway as a Novel Therapeutic Target for Trastuzumab-Mediated Cellular Cytotoxicity in Small Cell Lung Cancer
Authors: Yagishita Shigehiro , Fujita Yu , Kitazono Satoru , Ko Ryo , Nakadate Yusuke , Sawada Takeshi , Kitamura Yuka , Shimoyama Tatsu , Maeda Yoshiharu , Takahashi Fumiyuki , Takahashi Kazuhisa , Tamura Tomohide , Koizumi Fumiaki
Published: March 2024

Abstract
Small cell lung cancer (SCLC) accounts for 15% of all lung cancer cases and is a highly lethal disease. For the last several decades, the standard treatment for SCLC has been deadlocked, and new therapeutic strategies are urgently needed. HER2 is a member of the HER family and has been reported to be overexpressed in 30% of SCLC cases with poor prognosis. However, the clinical relevance of HER2-targeted therapy for SCLC remains unclear. Here, we first identify that cytotoxic drugs induce significant HER2 overexpression through microRNA-125a (miR-125a) and miR-125b downregulation, which in turn act as a novel therapeutic target for trastuzumab-mediated cellular cytotoxicity in SCLC. In this study, we showed that treatment of the HER2-positive SCLC cells, SBC-3 and SBC-5, with cytotoxic drugs induced a significant upregulation of HER2. Cisplatin (CDDP) treatment of SCLC cells resulted in a significant downregulation of miR-125a and miR-125b. We confirmed that miR-125a and miR-125b bound to the 3′-untranslated regions of HER2 mRNA, and that downregulation of miR-125a and miR-125b resulted in upregulation of HER2 in SCLC cells, suggesting a relationship between cytotoxic drug exposure and miR-125/HER2 dysregulation. Furthermore, using a calcein assay, we demonstrated a significantly enhanced cytotoxic effect of CDDP and trastuzumab that was mediated via antibody-dependent cellular cytotoxicity. Finally, we clearly demonstrated the enhanced antitumor effect of these agents in an orthotopic lung cancer model in vivo. Our results offer a novel therapeutic strategy for HER2-positive SCLCs by using trastuzumab combined with cytotoxic drugs. Mol Cancer Ther; 14(6); 1414–23. ©2015 AACR.
Data from Metformin Blocks Melanoma Invasion and Metastasis Development in AMPK/p53-Dependent Manner
Authors: Cerezo Michaël , Tichet Mélanie , Abbe Patricia , Ohanna Mickaël , Lehraiki Abdelali , Rouaud Florian , Allegra Maryline , Giacchero Damien , Bahadoran Philippe , Bertolotto Corine , Tartare-Deckert Sophie , Ballotti Robert , Rocchi Stéphane
Published: March 2024

Abstract
Metformin was reported to inhibit the proliferation of many cancer cells, including melanoma cells. In this report, we investigated the effect of metformin on melanoma invasion and metastasis development. Using different in vitro approaches, we found that metformin inhibits cell invasion without affecting cell migration and independently of antiproliferation action. This inhibition is correlated with modulation of expression of proteins involved in epithelial–mesenchymal transition such as Slug, Snail, SPARC, fibronectin, and N-cadherin and with inhibition of MMP-2 and MMP-9 activation. Furthermore, our data indicate that this process is dependent on activation of AMPK and tumor suppressor protein p53. Finally, we showed that metformin inhibits melanoma metastasis development in mice using extravasation and metastasis models. The presented data reinforce the fact that metformin might be a good candidate for clinical trial in melanoma treatment. Mol Cancer Ther; 12(8); 1605–15. ©2013 AACR.
Data from Overlapping Functions of ABC Transporters in Topotecan Disposition as Determined in Gene Knockout Mouse Models
Authors: Tiwari Amit K. , Zhang Rong , Gallo James M.
Published: March 2024

Abstract
It is established that efflux transporters of the ATP-binding cassette (ABC) superfamily can affect the pharmacokinetics of drugs through mechanisms pertaining to drug absorption, elimination, and distribution. To characterize the role of multiple transporters in topotecan's pharmacokinetics, total (lactone+carboxylate) and lactone forms were measured by liquid chromatography/tandem mass spectrometry (LC/MS-MS) in plasma, bile, urine, and feces following intravenous administration at doses of 1 and 4 mg/kg to eight mouse strains: C57BL/6 [wild-type (WT)], Abcb1−/−, Abcc2−/−, Abcc4−/−, Abcg2−/−, Abcc2;Abcb1−/−, Abcc2;Abcg2−/−, and Abcc4;Abcg2−/−. Compared with WT mice and at both dose levels, the plasma areas under the curve for topotecan lactone were not significantly different in the Abcc2−/−, Abcc4−/−, and Abcb1−/− strains, whereas significant differences were found in Abcg2−/−, Abcc2;Abcb1−/− (only at the high dose), Abcc4;Abcg2−/−, and Abcc2;Abcg2−/− mice and ranged from 2.1- to 3.3-fold higher. Consistent with these changes, the fecal and biliary excretion of topotecan was reduced, whereas renal elimination was elevated in Abcg2−/−-based strains. Similarly, the Abcc2;Abcb1−/− strain also had elevated renal elimination and reduced fecal excretion of topotecan lactone. This was more pronounced at the 4 mg/kg dose level, suggesting possible saturation of Abcg2. The Abcc4 transporter was found not to be a major determinant of topotecan pharmacokinetics. It is concluded that Abcg2 has the most significant effect on topotecan elimination, whereas both Abcb1 and Abcc2 have overlapping functions with Abcg2. As such it is relevant to examine how polymorphisms in these transporters influence topotecan activity in patients and whether coadministration of transport modulators could positively affect efficacy without increasing toxicity. Mol Cancer Ther; 12(7); 1343–55. ©2013 AACR.
Data from BET Bromodomain Inhibitors Block Growth of Pancreatic Cancer Cells in Three-Dimensional Collagen
Authors: Sahai Vaibhav , Kumar Krishan , Knab Lawrence M. , Chow Christina R. , Raza Sania S. , Bentrem David J. , Ebine Kazumi , Munshi Hidayatullah G.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is associated with pronounced fibrosis that contributes to chemoresistance, in part, through increased histone acetylation. Because bromodomain (BRD) and extra terminal domain (BET) proteins are “readers” of histone acetylation marks, we targeted BET proteins in PDAC cells grown in three-dimensional collagen. We show that treatment with BET inhibitors decreases growth of PDAC cells (AsPC1, CD18, and Panc1) in collagen. Transfection with siRNA against BRD4, which is increased in human PDAC tumors, also decreases growth of PDAC cells. BET inhibitors additionally decrease growth in collagen of PDAC cells that have undergone epithelial-to-mesenchymal transition or have become resistant to chemotherapy. Although BET inhibitors and BRD4 siRNA repress c-MYC only in AsPC1 and CD18 cells, downregulating c-MYC decreases growth of all three PDAC cell lines in collagen. FOSL1, which is also targeted by BET inhibitors and BRD4 siRNA in AsPC1, CD18, and Panc1 cells, additionally regulates growth of all three PDAC cell lines in collagen. BET inhibitors and BRD4 siRNA repress HMGA2, an architectural protein that modulates chromatin state and also contributes to chemoresistance, in PDAC cells grown in collagen. Importantly, we show that there is a statistically significant correlation between BRD4 and HMGA2 in human PDAC tumors. Significantly, overexpression of HMGA2 partially mitigates the effect of BET inhibitors on growth and c-MYC and/or FOSL1 expression in collagen. Overall, these results demonstrate that BET inhibitors block growth of PDAC cells in collagen and that BET proteins may be potential targets for the treatment of pancreatic cancer. Mol Cancer Ther; 13(7); 1907–17. ©2014 AACR.
Data from Angiotensin-(1-7) Decreases Cell Growth and Angiogenesis of Human Nasopharyngeal Carcinoma Xenografts
Authors: Pei Nana , Wan Renqiang , Chen Xinglu , Li Andrew , Zhang Yanling , Li Jinlong , Du Hongyan , Chen Baihong , Wei Wenjin , Qi Yanfei , Zhang Yi , Katovich Michael J. , Sumners Colin , Zheng Haifa , Li Hongwei
Published: March 2024

Abstract
Angiotensin-(1-7) [Ang-(1-7)] is an endogenous, heptapeptide hormone acting through the Mas receptor (MasR), with antiproliferative and antiangiogenic properties. Recent studies have shown that Ang-(1-7) has an antiproliferative action on lung adenocarcinoma cells and prostate cancer cells. In this study, we report that MasR levels were significantly upregulated in nasopharyngeal carcinoma (NPC) specimens and NPC cell lines. Viral vector–mediated expression of Ang-(1-7) dramatically suppressed NPC cell proliferation and migration in vitro. These effects were completely blocked by the specific Ang-(1-7) receptor antagonist A-779, suggesting that they are mediated by the Ang-(1-7) receptor Mas. In this study, Ang-(1-7) not only caused a significant reduction in the growth of human nasopharyngeal xenografts, but also markedly decreased vessel density, suggesting that the heptapeptide inhibits angiogenesis to reduce tumor size. Mechanistic investigations revealed that Ang-(1-7) inhibited the expression of the proangiogenic factors VEGF and PlGF. Taken together, the data suggest that upregulation of MasR could be used as a diagnostic marker of NPC and Ang-(1-7) may be a novel therapeutic agent for nasopharyngeal cancer therapy because it exerts significant antiangiogenic activity. Mol Cancer Ther; 15(1); 37–47. ©2015 AACR.
Data from Combination of Anti-HER3 Antibody MM-121/SAR256212 and Cetuximab Inhibits Tumor Growth in Preclinical Models of Head and Neck Squamous Cell Carcinoma
Authors: Jiang Ning , Wang Dongsheng , Hu Zhongliang , Shin Hyung Ju C. , Qian Guoqing , Rahman Mohammad Aminur , Zhang Hongzheng , Amin A.R.M. Ruhul , Nannapaneni Sreenivas , Wang Xiaojing , Chen Zhengjia , Garcia Gabriela , MacBeath Gavin , Shin Dong M. , Khuri Fadlo R. , Ma Jun , Chen Zhuo G. , Saba Nabil F.
Published: March 2024

Abstract
The EGFR monoclonal antibody cetuximab is the only approved targeted agent for treating head and neck squamous cell carcinoma (HNSCC). Yet resistance to cetuximab has hindered its activity in this disease. Intrinsic or compensatory HER3 signaling may contribute to cetuximab resistance. To investigate the therapeutic benefit of combining MM-121/SAR256212, an anti-HER3 monoclonal antibody, with cetuximab in HNSCC, we initially screened 12 HNSCC cell lines for total and phosphorylated levels of the four HER receptors. We also investigated the combination of MM-121 with cetuximab in preclinical models of HNSCC. Our results revealed that HER3 is widely expressed and activated in HNSCC cell lines. MM-121 strongly inhibited phosphorylation of HER3 and AKT. When combined with cetuximab, MM-121 exerted a more potent antitumor activity through simultaneously inhibiting the activation of HER3 and EGFR and consequently the downstream PI3K/AKT and ERK pathways in vitro. Both high and low doses of MM-121 in combination with cetuximab significantly suppressed tumor growth in xenograft models and inhibited activations of HER3, EGFR, AKT, and ERK in vivo. Our work is the first report on this new combination in HNSCC and supports the concept that HER3 inhibition may play an important role in future therapy of HNSCC. Our results open the door for further mechanistic studies to better understand the role of HER3 in resistance to EGFR inhibitors in HNSCC. Mol Cancer Ther; 13(7); 1826–36. ©2014 AACR.
Data from Inhibition of Homologous Recombination and Promotion of Mutagenic Repair of DNA Double-Strand Breaks Underpins Arabinoside–Nucleoside Analogue Radiosensitization
Authors: Magin Simon , Papaioannou Maria , Saha Janapriya , Staudt Christian , Iliakis George
Published: March 2024

Abstract
In concurrent chemoradiotherapy, drugs are used to sensitize tumors to ionizing radiation. Although a spectrum of indications for simultaneous treatment with drugs and radiation has been defined, the molecular mechanisms underpinning tumor radiosensitization remain incompletely characterized for several such combinations. Here, we investigate the mechanisms of radiosensitization by the arabinoside nucleoside analogue 9-β-D-arabinofuranosyladenine (araA) placing particular emphasis on the repair of DNA double-strand breaks (DSB), and compare the results to those obtained with fludarabine (F-araA) and cytarabine (araC). Postirradiation treatment with araA strongly sensitizes cells to ionizing radiation, but leaves unchanged DSB repair by NHEJ in logarithmically growing cells, in sorted G1 or G2 phase populations, as well as in cells in the plateau phase of growth. Notably, araA strongly inhibits DSB repair by homologous recombination (HRR), as assessed by scoring ionizing radiation–induced RAD51 foci, and in functional assays using integrated reporter constructs. Cells compromised in HRR by RNAi-mediated transient knockdown of RAD51 show markedly reduced radiosensitization after treatment with araA. Remarkably, mutagenic DSB repair compensates for HRR inhibition in araA-treated cells. Compared with araA, F-araA and araC are only modestly radiosensitizing under the conditions examined. We propose that the radiosensitizing potential of nucleoside analogues is linked to their ability to inhibit HRR and concomitantly promote the error-prone processing of DSBs. Our observations pave the way to treatment strategies harnessing the selective inhibitory potential of nucleoside analogues and the development of novel compounds specifically utilizing HRR inhibition as a means of tumor cell radiosensitization. Mol Cancer Ther; 14(6); 1424–33. ©2015 AACR.
Data from REST Negatively and ISGF3 Positively Regulate the Human STAT1 Gene in Melanoma
Authors: Amalraj James , Cutler Samuel J. , Ghazawi Ibtisam , Boyle Glen M. , Ralph Stephen J.
Published: March 2024

Abstract
STAT1 plays a pivotal role in signal transduction and transcriptional activation in response to type I and II IFNs. Regulation of STAT1 expression has significant consequences in human cancer cells, where STAT1 deficiencies have been associated with cellular resistance to type I IFN. Distinct promoter, enhancer, and repressor regions have previously been described in the regulatory part of the human STAT1 gene extending as far as the second intron. A putative IFN-stimulated response element sequence in the STAT1 promoter is inducible by type I IFN and binds the IFN-α/β–induced complex, ISGF3. Together with the previously characterized IRF-E/GAS/IRF-E (IGI) motif, these positive regulatory elements provide a means for intracellular amplification of STAT1 expression, which is necessary for increasing cell responsiveness to the IFNs. In contrast, the transcriptional repressor REST binds to an RE-1 element in the STAT1 repressor region and in doing so represses transcription from the STAT1 gene regulatory region in melanoma cells lines. Repression significantly decreased in a REST-null cell line. Altering REST function from a transcriptional repressor into an activator as REST-VP16 increased expression from RE-1–targeted reporters. RNA expression of 65 melanoma cell lines by microarray and selected lines with known IFN responsiveness showed significant inverse correlations between STAT1/REST that were related to cellular responses to IFN. Thus REST, through the intronic RE-1 element, provides a means for downregulating STAT1 expression, affecting melanoma responsiveness to IFN. Intracellular levels of REST may be a useful marker to test for IFN resistance and as a novel therapeutic target in IFN-resistant melanomas. Mol Cancer Ther; 12(7); 1288–98. ©2013 AACR.
Data from Epithelial-to-Mesenchymal Transition Mediates Docetaxel Resistance and High Risk of Relapse in Prostate Cancer
Authors: Marín-Aguilera Mercedes , Codony-Servat Jordi , Reig Òscar , Lozano Juan José , Fernández Pedro Luis , Pereira María Verónica , Jiménez Natalia , Donovan Michael , Puig Pere , Mengual Lourdes , Bermudo Raquel , Font Albert , Gallardo Enrique , Ribal María José , Alcaraz Antonio , Gascón Pere , Mellado Begoña
Published: March 2024

Abstract
Molecular characterization of radical prostatectomy specimens after systemic therapy may identify a gene expression profile for resistance to therapy. This study assessed tumor cells from patients with prostate cancer participating in a phase II neoadjuvant docetaxel and androgen deprivation trial to identify mediators of resistance. Transcriptional level of 93 genes from a docetaxel-resistant prostate cancer cell lines microarray study was analyzed by TaqMan low-density arrays in tumors from patients with high-risk localized prostate cancer (36 surgically treated, 28 with neoadjuvant docetaxel + androgen deprivation). Gene expression was compared between groups and correlated with clinical outcome. VIM, AR and RELA were validated by immunohistochemistry. CD44 and ZEB1 expression was tested by immunofluorescence in cells and tumor samples. Parental and docetaxel-resistant castration-resistant prostate cancer cell lines were tested for epithelial-to-mesenchymal transition (EMT) markers before and after docetaxel exposure. Reversion of EMT phenotype was investigated as a docetaxel resistance reversion strategy. Expression of 63 (67.7%) genes differed between groups (P < 0.05), including genes related to androgen receptor, NF-κB transcription factor, and EMT. Increased expression of EMT markers correlated with radiologic relapse. Docetaxel-resistant cells had increased EMT and stem-like cell markers expression. ZEB1 siRNA transfection reverted docetaxel resistance and reduced CD44 expression in DU-145R and PC-3R. Before docetaxel exposure, a selected CD44+ subpopulation of PC-3 cells exhibited EMT phenotype and intrinsic docetaxel resistance; ZEB1/CD44+ subpopulations were found in tumor cell lines and primary tumors; this correlated with aggressive clinical behavior. This study identifies genes potentially related to chemotherapy resistance and supports evidence of the EMT role in docetaxel resistance and adverse clinical behavior in early prostate cancer. Mol Cancer Ther; 13(5); 1270–84. ©2014 AACR.
Data from Quinacrine Overcomes Resistance to Erlotinib by Inhibiting FACT, NF-κB, and Cell-Cycle Progression in Non–Small Cell Lung Cancer
Authors: Dermawan Josephine Kam Tai , Gurova Katerina , Pink John , Dowlati Afshin , De Sarmishtha , Narla Goutham , Sharma Neelesh , Stark George R.
Published: March 2024

Abstract
Erlotinib is a tyrosine kinase inhibitor approved for the treatment of patients with advanced non–small cell lung cancer (NSCLC). In these patients, erlotinib prolongs survival but its benefit remains modest because many tumors express wild-type (wt) EGFR or develop a second-site EGFR mutation. To test drug combinations that could improve the efficacy of erlotinib, we combined erlotinib with quinacrine, which inhibits the FACT (facilitates chromatin transcription) complex that is required for NF-κB transcriptional activity. In A549 (wtEGFR), H1975 (EGFR-L858R/T790M), and H1993 (MET amplification) NSCLC cells, this drug combination was highly synergistic, as quantified by Chou–Talalay combination indices, and slowed xenograft tumor growth. At a sub-IC50 but more clinically attainable concentration of erlotinib, quinacrine, alone or in combination with erlotinib, significantly inhibited colony formation and induced cell-cycle arrest and apoptosis. Quinacrine decreased the level of active FACT subunit SSRP1 and suppressed NF-κB–dependent luciferase activity. Knockdown of SSRP1 decreased cell growth and sensitized cells to erlotinib. Moreover, transcriptomic profiling showed that quinacrine or combination treatment significantly affected cell-cycle–related genes that contain binding sites for transcription factors that regulate SSRP1 target genes. As potential biomarkers of drug combination efficacy, we identified genes that were more strongly suppressed by the combination than by single treatment, and whose increased expression predicted poorer survival in patients with lung adenocarcinoma. This preclinical study shows that quinacrine overcomes erlotinib resistance by inhibiting FACT and cell-cycle progression, and supports a clinical trial testing erlotinib alone versus this combination in advanced NSCLC. Mol Cancer Ther; 13(9); 2203–14. ©2014 AACR.
Data from The 1,2-Diaminocyclohexane Carrier Ligand in Oxaliplatin Induces p53-Dependent Transcriptional Repression of Factors Involved in Thymidylate Biosynthesis
Authors: Kiyonari Shinichi , Iimori Makoto , Matsuoka Kazuaki , Watanabe Sugiko , Morikawa-Ichinose Tomomi , Miura Daisuke , Niimi Shinichiro , Saeki Hiroshi , Tokunaga Eriko , Oki Eiji , Morita Masaru , Kadomatsu Kenji , Maehara Yoshihiko , Kitao Hiroyuki
Published: March 2024

Abstract
Platinum-based chemotherapeutic drugs are widely used as components of combination chemotherapy in the treatment of cancer. One such drug, oxaliplatin, exerts a synergistic effect against advanced colorectal cancer in combination with 5-fluorouracil (5-FU) and leucovorin. In the p53-proficient colorectal cancer cell line HCT116, oxaliplatin represses the expression of deoxyuridine triphosphatase (dUTPase), a ubiquitous pyrophosphatase that catalyzes the hydrolysis of dUTP to dUMP and inhibits dUTP-mediated cytotoxicity. However, the underlying mechanism of this activity has not been completely elucidated, and it remains unclear whether factors other than downregulation of dUTPase contribute to the synergistic effect of 5-FU and oxaliplatin. In this study, we found that oxaliplatin and dachplatin, platinum-based drugs containing the 1,2-diaminocyclohexane (DACH) carrier ligand, repressed the expression of nuclear isoform of dUTPase (DUT-N), whereas cisplatin and carboplatin did not. Oxaliplatin induced early p53 accumulation, upregulation of primary miR-34a transcript expression, and subsequent downregulation of E2F3 and E2F1. Nutlin-3a, which activates p53 nongenotoxically, had similar effects. Introduction of miR-34a mimic also repressed E2F1 and DUT-N expression, indicating that this miRNA plays a causative role. In addition to DUT-N, oxaliplatin repressed, in a p53-dependent manner, the expression of genes encoding enzymes involved in thymidylate biosynthesis. Consequently, oxaliplatin significantly decreased the level of dTTP in the dNTP pool in a p53-dependent manner. These data indicate that the DACH carrier ligand in oxaliplatin triggers signaling via the p53–miR-34a–E2F axis, leading to transcriptional regulation that ultimately results in accumulation of dUTP and reduced dTTP biosynthesis, potentially enhancing 5-FU cytotoxicity. Mol Cancer Ther; 14(10); 2332–42. ©2015 AACR.
Data from Polymorphisms in Genes Involved in EGFR Turnover Are Predictive for Cetuximab Efficacy in Colorectal Cancer
Authors: Stintzing Sebastian , Zhang Wu , Heinemann Volker , Neureiter Daniel , Kemmerling Ralf , Kirchner Thomas , Jung Andreas , Folwaczny Matthias , Yang Dongyun , Ning Yan , Sebio Ana , Stremitzer Stefan , Sunakawa Yu , Matsusaka Satoshi , Yamauchi Shinichi , Loupakis Fotios , Cremolini Chiara , Falcone Alfredo , Lenz Heinz-Josef
Published: March 2024

Abstract
Transmembrane receptors, such as the EGFR, are regulated by their turnover, which is dependent on the ubiquitin-proteasome system. We tested in two independent study cohorts whether SNPs in genes involved in EGFR turnover predict clinical outcome in cetuximab-treated metastatic colorectal cancer (mCRC) patients. The following SNPs involved in EGFR degradation were analyzed in a screening cohort of 108 patients treated with cetuximab in the chemorefractory setting: c-CBL (rs7105971; rs4938637; rs4938638; rs251837), EPS15 (rs17567; rs7308; rs1065754), NAE1 (rs363169; rs363170; rs363172), SH3KBP1 (rs7051590; rs5955820; rs1017874; rs11795873), SGIP1 (rs604737; rs6570808; rs7526812), UBE2M (rs895364; rs895374), and UBE2L3 (rs5754216). SNPs showing an association with response or survival were analyzed in BRAF and RAS wild-type samples from the FIRE-3 study. One hundred and fifty-three FOLFIRI plus cetuximab-treated patients served as validation set, and 168 patients of the FOLFIRI plus bevacizumab arm served as controls. EGFR FISH was done in 138 samples to test whether significant SNPs were associated with EGFR expression. UBE2M rs895374 was significantly associated with progression-free survival (log-rank P = 0.005; HR, 0.60) within cetuximab-treated patients. No association with bevacizumab-treated patients (n = 168) could be established (P = 0.56; HR, 0.90). rs895374 genotype did not affect EGFR FISH measurements. EGFR recycling is an interesting mechanism of secondary resistance to cetuximab in mCRC. This is the first report suggesting that germline polymorphisms in the degradation process predict efficacy of cetuximab in patients with mCRC. Genes involved in EGFR turnover may be new targets in the treatment of mCRC. Mol Cancer Ther; 14(10); 2374–81. ©2015 AACR.
Data from Direct Binding of Arsenic Trioxide to AMPK and Generation of Inhibitory Effects on Acute Myeloid Leukemia Precursors
Authors: Beauchamp Elspeth M. , Kosciuczuk Ewa M. , Serrano Ruth , Nanavati Dhaval , Swindell Elden P. , Viollet Benoit , O'Halloran Thomas V. , Altman Jessica K. , Platanias Leonidas C.
Published: March 2024

Abstract
Arsenic trioxide (As2O3) exhibits potent antineoplastic effects and is used extensively in clinical oncology for the treatment of a subset of patients with acute myeloid leukemia (AML). Although As2O3 is known to regulate activation of several signaling cascades, the key events, accounting for its antileukemic properties, remain to be defined. We provide evidence that arsenic can directly bind to cysteine 299 in AMPKα and inhibit its activity. This inhibition of AMPK by arsenic is required in part for its cytotoxic effects on primitive leukemic progenitors from patients with AML, while concomitant treatment with an AMPK activator antagonizes in vivo the arsenic-induced antileukemic effects in a xenograft AML mouse model. A consequence of AMPK inhibition is activation of the mTOR pathway as a negative regulatory feedback loop. However, when AMPK expression is lost, arsenic-dependent activation of the kinase RSK downstream of MAPK activity compensates the generation of regulatory feedback signals through phosphorylation of downstream mTOR targets. Thus, therapeutic regimens with As2O3 will need to include inhibitors of both the mTOR and RSK pathways in combination to prevent engagement of negative feedback loops and maximize antineoplastic responses. Mol Cancer Ther; 14(1); 202–12. ©2014 AACR.
Data from Aromatase Inhibitor–Mediated Downregulation of INrf2 (Keap1) Leads to Increased Nrf2 and Resistance in Breast Cancer
Authors: Khatri Raju , Shah Preeti , Guha Rupa , Rassool Feyruz V. , Tomkinson Alan E. , Brodie Angela , Jaiswal Anil K.
Published: March 2024

Abstract
Aromatase inhibitors are effective drugs that reduce or eliminate hormone-sensitive breast cancer. However, despite their efficacy, resistance to these drugs can occur in some patients. The INrf2 (Keap1):Nrf2 complex serves as a sensor of drug/radiation-induced oxidative/electrophilic stress. INrf2 constitutively suppresses Nrf2 by functioning as an adapter protein for the Cul3/Rbx1-mediated ubiquitination/degradation of Nrf2. Upon stress, Nrf2 dissociates from INrf2, is stabilized, translocates to the nucleus, and coordinately induces a battery of cytoprotective gene expression. Current studies investigated the role of Nrf2 in aromatase inhibitor resistance. RT-PCR and immunoblot assays showed that aromatase inhibitor–resistant breast cancer LTLTCa and AnaR cells express lower INrf2 and higher Nrf2 protein levels, as compared with drug-sensitive MCF-7Ca and AC1 cells, respectively. The increase in Nrf2 was due to lower ubiquitination/degradation of Nrf2 in aromatase inhibitor–resistant cells. Higher Nrf2-mediated levels of biotransformation enzymes, drug transporters, and antiapoptotic proteins contributed to reduced efficacy of drugs and aversion to apoptosis that led to drug resistance. shRNA inhibition of Nrf2 in LTLTCa (LTLTCa-Nrf2KD) cells reduced resistance and sensitized cells to aromatase inhibitor exemestane. Interestingly, LTLTCa-Nrf2KD cells also showed reduced levels of aldehyde dehydrogenase, a marker of tumor-initiating cells and significantly decreased mammosphere formation, as compared with LTLTCa-Vector control cells. The results together suggest that persistent aromatase inhibitor treatment downregulated INrf2 leading to higher expression of Nrf2 and Nrf2-regulated cytoprotective proteins that resulted in increased aromatase inhibitor drug resistance. These findings provide a rationale for the development of Nrf2 inhibitors to overcome resistance and increase efficacy of aromatase inhibitors. Mol Cancer Ther; 14(7); 1728–37. ©2015 AACR.
Data from Cosilencing of PKM-2 and MDR-1 Sensitizes Multidrug-Resistant Ovarian Cancer Cells to Paclitaxel in a Murine Model of Ovarian Cancer
Authors: Talekar Meghna , Ouyang Qijun , Goldberg Michael S. , Amiji Mansoor M.
Published: March 2024

Abstract
Tumor multidrug resistance (MDR) is a serious clinical challenge that significantly limits the effectiveness of cytotoxic chemotherapy. As such, complementary therapeutic strategies are being explored to prevent relapse. The altered metabolic state of cancer cells, which perform aerobic glycolysis, represents an interesting target that can enable discrimination between healthy cells and cancer cells. We hypothesized that cosilencing of genes responsible for aerobic glycolysis and for MDR would have synergistic antitumor effect. In this study, siRNA duplexes against pyruvate kinase M2 and multidrug resistance gene-1 were encapsulated in hyaluronic acid–based self-assembling nanoparticles. The particles were characterized for morphology, size, charge, encapsulation efficiency, and transfection efficiency. In vivo studies included biodistribution assessment, gene knockdown confirmation, therapeutic efficacy, and safety analysis. The benefit of active targeting of cancer cells was confirmed by modifying the particles' surface with a peptide targeted to epidermal growth factor receptor, which is overexpressed on the membranes of the SKOV-3 cancer cells. To augment the studies involving transplantation of a paclitaxel-resistant cell line, an in vivo paclitaxel resistance model was developed by injecting repeated doses of paclitaxel following tumor inoculation. The nanoparticles accumulated significantly in the tumors, hindering tumor volume doubling time (P < 0.05) upon combination therapy in both the wild-type (2-fold) and resistant (8-fold) xenograft models. Although previous studies indicated that silencing of MDR-1 alone sensitized MDR ovarian cancer to paclitaxel only modestly, these data suggest that concurrent silencing of PKM-2 improves the efficacy of paclitaxel against MDR ovarian cancer. Mol Cancer Ther; 14(7); 1521–31. ©2015 AACR.
Data from IMGN853, a Folate Receptor-α (FRα)–Targeting Antibody–Drug Conjugate, Exhibits Potent Targeted Antitumor Activity against FRα-Expressing Tumors
Authors: Ab Olga , Whiteman Kathleen R. , Bartle Laura M. , Sun Xiuxia , Singh Rajeeva , Tavares Daniel , LaBelle Alyssa , Payne Gillian , Lutz Robert J. , Pinkas Jan , Goldmacher Victor S. , Chittenden Thomas , Lambert John M.
Published: March 2024

Abstract
A majority of ovarian and non–small cell lung adenocarcinoma cancers overexpress folate receptor α (FRα). Here, we report the development of an anti-FRα antibody–drug conjugate (ADC), consisting of a FRα-binding antibody attached to a highly potent maytansinoid that induces cell-cycle arrest and cell death by targeting microtubules. From screening a large panel of anti-FRα monoclonal antibodies, we selected the humanized antibody M9346A as the best antibody for targeted delivery of a maytansinoid payload into FRα-positive cells. We compared M9346A conjugates with various linker/maytansinoid combinations, and found that a conjugate, now denoted as IMGN853, with the N-succinimidyl 4-(2-pyridyldithio)-2-sulfobutanoate (sulfo-SPDB) linker and N2′-deacetyl-N2′-(4-mercapto-4-methyl-1-oxopentyl)-maytansine (DM4) exhibited the most potent antitumor activity in several FRα-expressing xenograft tumor models. The level of expression of FRα on the surface of cells was a major determinant in the sensitivity of tumor cells to the cytotoxic effect of the conjugate. Efficacy studies of IMGN853 in xenografts of ovarian cancer and non–small cell lung cancer cell lines and of a patient tumor-derived xenograft model demonstrated that the ADC was highly active against tumors that expressed FRα at levels similar to those found on a large fraction of ovarian and non-small cell lung cancer patient tumors, as assessed by immunohistochemistry. IMGN853 displayed cytotoxic activity against FRα-negative cells situated near FRα-positive cells (bystander cytotoxic activity), indicating its ability to eradicate tumors with heterogeneous expression of FRα. Together, these findings support the clinical development of IMGN853 as a novel targeted therapy for patients with FRα-expressing tumors. Mol Cancer Ther; 14(7); 1605–13. ©2015 AACR.
Data from Antibody against Granulin–Epithelin Precursor Sensitizes Hepatocellular Carcinoma to Chemotherapeutic Agents
Authors: Wong Nicholas C.L. , Cheung Phyllis F.Y. , Yip Chi Wai , Chan Kui Fat , Ng Irene Oi-Lin , Fan Sheung Tat , Cheung Siu Tim
Published: March 2024

Abstract
Granulin–epithelin precursor (GEP) overexpression has been shown in many cancers with functional role on growth, and recently on regulating chemoresistance and cancer stem cell (CSC) properties. Here, we investigate the combined effect of GEP antibody and chemotherapeutic agent. Combination therapy was compared with monotherapy using hepatocellular carcinoma (HCC) cells in vitro and orthotopic liver tumor models in vivo. CD133 and related hepatic CSC marker expressions were investigated by flow cytometry. Antiproliferative and apoptotic effects and signaling mechanisms were examined by immunohistochemistry, flow cytometry, and Western blot analysis. Secretory GEP levels in the serum and culture supernatant samples were measured by ELISA. We demonstrated that HCC cells that survived under chemotherapeutic agents showed upregulation of hepatic CSC markers CD133/GEP/ABCB5, and enhanced colony and spheroid formation abilities. Importantly, GEP antibody sensitized HCC cells to the apoptosis induced by chemotherapy for both HCC cell lines and the chemoresistant subpopulations, and counteracted the chemotherapy-induced GEP/ABCB5 expressions and Akt/Bcl-2 signaling. In human HCC orthotopic xenograft models, GEP antibody treatment alone was consistently capable of inhibiting the tumor growth. Notably, combination of GEP antibody with high dose of cisplatin resulted in the eradication of all established intrahepatic tumor in three weeks. This preclinical study demonstrated that GEP antibody sensitized HCC cells to apoptosis induced by chemotherapeutic agents. Combination treatment with GEP antibody and chemotherapeutic agent has the potential to be an effective therapeutic regimen for GEP-expressing cancers. Mol Cancer Ther; 13(12); 3001–12. ©2014 AACR.
Data from Histone Deacetylase 6 Represents a Novel Drug Target in the Oncogenic Hedgehog Signaling Pathway
Authors: Dhanyamraju Pavan Kumar , Holz Philipp Simon , Finkernagel Florian , Fendrich Volker , Lauth Matthias
Published: March 2024

Abstract
Uncontrolled Hedgehog (Hh) signaling is the cause of several malignancies, including the pediatric cancer medulloblastoma, a neuroectodermal tumor affecting the cerebellum. Despite the development of potent Hh pathway antagonists, medulloblastoma drug resistance is still an unresolved issue that requires the identification of novel drug targets. Following up on our observation that histone deacetylase 6 (HDAC6) expression was increased in Hh-driven medulloblastoma, we found that this enzyme is essential for full Hh pathway activation. Intriguingly, these stimulatory effects of HDAC6 are partly integrated downstream of primary cilia, a known HDAC6-regulated structure. In addition, HDAC6 is also required for the complete repression of basal Hh target gene expression. These contrasting effects are mediated by HDAC6′s impact on Gli2 mRNA and GLI3 protein expression. As a result of this complex interaction with Hh signaling, global transcriptome analysis revealed that HDAC6 regulates only a subset of Smoothened- and Gli-driven genes, including all well-established Hh targets such as Ptch1 or Gli1. Importantly, medulloblastoma cell survival was severely compromised by HDAC6 inhibition in vitro and pharmacologic HDAC6 blockade strongly reduced tumor growth in an in vivo allograft model. In summary, our data describe an important role for HDAC6 in regulating the mammalian Hh pathway and encourage further studies focusing on HDAC6 as a novel drug target in medulloblastoma. Mol Cancer Ther; 14(3); 727–39. ©2014 AACR.
Data from Therapeutic Targeting of Angiogenesis with a Recombinant CTT Peptide–Endostatin Mimic–Kringle 5 Protein
Authors: Wang Houbin , Yang Zhigang , Gu Jun
Published: March 2024

Abstract
Angiogenesis is required for tumor growth and metastasis, and targeting angiogenesis is a novel anticancer strategy. However, cancer development is a complex multistep process, and single antiangiogenic agents have limited therapeutic efficacy. Here, we report a triple fusion protein, namely CTT peptide–endostatin mimic–kringle 5 (AARP), consisting of MMP-2/9–selective inhibitory peptide (CTT peptide) and well-known endogenous antiangiogenic agents (endostatin mimic and kringle 5), which can simultaneously target matrix metalloproteinases (MMP) and endothelial cells, blocking their actions. AARP was bacterially expressed, and biologic activity of purified AARP was assessed. AARP could significantly inhibit the enzymatic activity of MMP-2/9, proliferation, migration, and tube formation of endothelial cells in vitro. The antitumor activity of AARP was shown in a concentration-dependent manner when injected i.p. into immunodeficient mice bearing multidrug-resistant human epidermoid carcinomas (KB), and AARP is superior to clinical grade endostatin in inhibiting KB xenograft growth. In mouse models of Lewis lung carcinoma (LLC) and hepatoma H22, when given as a single dose, AARP is highly effective for reducing tumor growth, angiogenesis, and metastasis, and increasing survival time. AARP possessed significantly greater antiangiogenic activity than endostatin mimic, CTT peptide–kringle 5 (RK5) both in vitro and in vivo. Compared with conventional chemotherapeutic agents (cyclophosphamide and paclitaxel), AARP is also effective. More importantly, AARP is cytocompatible and no tissue toxicity could be observed after large dose administration. Taken together, our findings suggest AARP is a highly effective, safe, and more potent antiangiogenic agent for blocking tumor angiogenesis and metastasis, and warrants further testing for clinical applications. Mol Cancer Ther; 13(11); 2674–87. ©2014 AACR.
Data from Histone Deacetylase Inhibitors Inhibit Rhabdomyosarcoma by Reactive Oxygen Species–Dependent Targeting of Specificity Protein Transcription Factors
Authors: Hedrick Erik , Crose Lisa , Linardic Corinne M. , Safe Stephen
Published: March 2024

Abstract
The two major types of rhabdomyosarcoma (RMS) are predominantly diagnosed in children, namely embryonal (ERMS) and alveolar (ARMS) RMS, and patients are treated with cytotoxic drugs, which results in multiple toxic side effects later in life. Therefore, development of innovative chemotherapeutic strategies is imperative, and a recent genomic analysis suggested the potential efficacy of reactive oxygen species (ROS)–inducing agents. Here, we demonstrate the efficacy of the potent histone deacetylase (HDAC) inhibitors, panobinostat and vorinostat, as agents that inhibit RMS tumor growth in vivo, induce apoptosis, and inhibit invasion of RD and Rh30 RMS cell lines. These effects are due to epigenetic repression of cMyc, which leads to decreased expression of cMyc-regulated miRs-17, -20a, and -27a; upregulation of ZBTB4, ZBTB10, and ZBTB34; and subsequent downregulation of Sp transcription factors. We also show that inhibition of RMS cell growth, survival and invasion, and repression of Sp transcription factors by the HDAC inhibitors are independent of histone acetylation but reversible after cotreatment with the antioxidant glutathione. These results show a novel ROS-dependent mechanism of antineoplastic activity for panobinostat and vorinostat that lies outside of their canonical HDAC-inhibitory activity and demonstrates the potential clinical utility for treating RMS patients with ROS-inducing agents. Mol Cancer Ther; 14(9); 2143–53. ©2015 AACR.