bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Challenges in the Enumeration and Phenotyping of CTC
Authors: Coumans Frank A.W. , Ligthart Sjoerd T. , Uhr Jonathan W. , Terstappen Leon W.M.M.
Published: April 2023

Abstract
Purpose: Presence of circulating tumor cells (CTC) in metastatic carcinoma is associated with poor survival. Phenotyping and genotyping of CTC may permit “real-time” treatment decisions, provided CTCs are available for examination. Here, we investigate what is needed to detect CTC in all patients.

Experimental Design: CTCs enumerated in 7.5 mL of blood together with survival from 836 patients with metastatic breast, colorectal, and prostate cancer were used to predict the CTC concentration in the 42% of these patients in whom no CTCs were found and to establish the relation of concentration of CTCs with survival. Influence of different CTC definitions were investigated by automated cell recognition and a flow cytometric assay without an enrichment or permeabilization step.

Results: A log-logistic regression of the log of CTC yielded a good fit to the CTC frequency distribution. Extrapolation of the blood volume to 5 L predicted that 99% of patients had at least one CTC before therapy initiation. Survival of patients with EpCAM+, cytokeratin+, CD45− nucleated CTCs is reduced by 6.6 months for each 10-fold CTC increase. Using flow cytometry, the potential three-fold recovery improvement is not sufficient to detect CTC in all patients in 7.5 mL of blood.

Conclusions: EpCAM+, cytokeratin+, CD45− nucleated CTCs are present in all patients with metastatic breast, prostate, and colorectal cancer and their frequency is proportional to survival. To serve as a liquid biopsy for the majority of patients, a substantial improvement of CTC yield is needed, which can only be achieved by a dramatic increase in sample volume. Clin Cancer Res; 18(20); 5711–8. ©2012 AACR.
Data from Cap-Translation Inhibitor, 4EGI-1, Restores Sensitivity to ABT-737 Apoptosis through Cap-Dependent and -Independent Mechanisms in Chronic Lymphocytic Leukemia
Authors: Willimott Shaun , Beck Daniel , Ahearne Matthew J. , Adams Victoria C. , Wagner Simon D.
Published: April 2023

Abstract
Purpose: The lymph node microenvironment promotes resistance to chemotherapy in chronic lymphocytic leukemia (CLL), partly through induction of BCL2 family prosurvival proteins. Currently available inhibitors do not target all BCL2 family prosurvival proteins and their effectiveness is also modified by proapoptotic BCL2 homology domain 3 (BH3) only protein expression. The goal of this study was to evaluate synergy between the eIF4E/eIF4G interaction inhibitor, 4EGI-1, and the BH3 mimetic, ABT-737.

Experimental Design: CLL cells were cultured in conditions to mimic the lymph node microenvironment. Protein synthesis and cap-complex formation were determined. Polysome association of mRNAs from BCL2 family survival genes was analyzed by translational profiling. The effects of 4EGI-1 and the BCL2/BCL2L1 antagonist, ABT-737, on CLL cell apoptosis were determined.

Results: Protein synthesis was increased approximately 6-fold by stromal cell/CD154 culture in a phosphoinositide 3-kinase α (PI3Kα)–specific manner and was reduced by 4EGI-1. PI3K inhibitors and 4EGI-1 also reduced cap-complex formation but only 4EGI-1 consistently reduced BCL2L1 and BCL2A1 protein levels. 4EGI-1, but not PI3K inhibitors or rapamycin, induced an endoplasmic reticulum stress response including proapoptotic NOXA and the translation inhibitor phosphorylated eIF2α. 4EGI-1 and ABT-737 synergized to cause apoptosis, independent of levels of prosurvival protein expression in individual patients.

Conclusions: Overall protein synthesis and cap-complex formation are induced by microenvironment stimuli in CLL. Inhibition of the cap-complex was not sufficient to repress BCL2 family prosurvival expression, but 4EGI-1 inhibited BCL2A1 and BCL2L1 while inducing NOXA through cap-dependent and -independent mechanisms. 4EGI-1 and ABT-737 synergized to produce apoptosis, and these agents may be the basis for a therapeutically useful combination. Clin Cancer Res; 19(12); 3212–23. ©2013 AACR.
Data from KRAS and BRAF Mutations Predict Primary Resistance to Imatinib in Gastrointestinal Stromal Tumors
Authors: Miranda Claudia , Nucifora Martina , Molinari Francesca , Conca Elena , Anania Maria Chiara , Bordoni Andrea , Saletti Piercarlo , Mazzucchelli Luca , Pilotti Silvana , Pierotti Marco A. , Tamborini Elena , Greco Angela , Frattini Milo
Published: April 2023

Abstract
Purpose: Gastrointestinal stromal tumors (GIST) are characterized by gain-of-function mutations in KIT/PDGFRA genes leading to a constitutive receptor activation which is well counteracted by imatinib. However, cases in which imatinib as first-line treatment has no effects are reported (primary resistance). Our purpose is to investigate alterations in downstream effectors, not reported so far in mutated GIST, possibly explaining the primary resistance to targeted treatments.

Experimental Design: Two independent naive GIST cohorts have been analyzed for KIT, PDGFRA, KRAS, and BRAF mutations by direct sequencing. Cell lines expressing a constitutively activated and imatinib-responding KIT, alone or in combination with activated KRAS and BRAF, were produced and treated with imatinib. KIT receptor and its downstream effectors were analyzed by direct Western blotting.

Results: In naive GISTs carrying activating mutations in KIT or PDGFRA a concomitant activating mutation was detected in KRAS (5%) or BRAF (about 2%) genes. In vitro experiments showed that imatinib was able to switch off the mutated receptor KIT but not the downstream signaling triggered by RAS–RAF effectors.

Conclusions: These data suggest the activation of mitogen—activated protein kinase pathway as a possible novel mechanism of primary resistance to imatinib in GISTs and could explain the survival curves obtained from several clinical studies where 2% to 4% of patients with GIST treated with imatinib, despite carrying KIT-sensitive mutations, do not respond to the treatment. Clin Cancer Res; 18(6); 1769–76. ©2012 AACR.
Data from A Phase I Weekly Dosing Study of Brentuximab Vedotin in Patients with Relapsed/Refractory CD30-Positive Hematologic Malignancies
Authors: Fanale Michelle A. , Forero-Torres Andres , Rosenblatt Joseph D. , Advani Ranjana H. , Franklin Anna R. , Kennedy Dana A. , Han Tae H. , Sievers Eric L. , Bartlett Nancy L.
Published: April 2023

Abstract
Purpose: The antibody–drug conjugate (ADC) brentuximab vedotin comprises a CD30-directed antibody covalently attached to the potent antimicrotubule agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. This study explored the safety, maximum-tolerated dose (MTD), and activity of weekly dosing of brentuximab vedotin in patients with relapsed or refractory CD30-positive hematologic malignancies.

Experimental Design: In this phase I dose-escalation study, brentuximab vedotin was administered intravenously on Days 1, 8, and 15, of each 28-day cycle at doses ranging from 0.4 to 1.4 mg/kg. Forty-four patients were enrolled: 38 with Hodgkin lymphoma, five with systemic anaplastic large cell lymphoma, and one with peripheral T-cell lymphoma not otherwise specified. Doses were escalated in increments of 0.2 mg/kg until dose-limiting toxicity (DLT) was observed. Patients were monitored for antitherapeutic antibodies and pharmacokinetic parameters. Antitumor assessments were carried out every two cycles.

Results: The MTD was 1.2 mg/kg. The most common adverse events were peripheral sensory neuropathy, fatigue, nausea, diarrhea, arthralgia, and pyrexia; and the majority of events were mild to moderate in severity. Tumor regression occurred in 85% of patients and the overall objective response rate was 59% (n = 24), with 34% (n = 14) complete remissions. The median duration of response was not reached at a median follow-up of 45 weeks on study.

Conclusions: Weekly administration of brentuximab vedotin resulted in tumor regression and durable remissions in patients with CD30-positive malignancies. This ADC was associated with manageable toxicity, including peripheral neuropathy. Further study in CD30-positive malignancies is warranted. Clin Cancer Res; 18(1); 248–55. ©2011 AACR.
Data from Therapeutic Drug Monitoring of Imatinib—New Data Strengthen the Case
Authors: Judson Ian
Published: April 2023

Abstract
A population pharmacokinetic study of imatinib in patients with gastrointestinal stromal tumor by Eechoute and colleagues has shown a significant increase in drug clearance over the first 3 months of treatment, resulting in a 30% decrease in drug exposure. This finding clearly shows the possibility of pharmacokinetic resistance in this disease. Clin Cancer Res; 18(20); 5517–9. ©2012 AACR.
Data from Model T Muscle CARs Can Treat Brain Tumors
Authors: Johnson Laura A.
Published: April 2023

Abstract
Despite standard treatment with resection, radiation, and chemotherapy, glioblastoma remains a deadly disease with a dismal prognosis. Redirecting patient T cells to target the glioblastoma-associated antigen, IL13Rα2, offers a promising translational immunotherapy with the potential to make a meaningful impact for patients with this disease. Clin Cancer Res; 18(21); 5834–6. ©2012 AACR.
Data from Regulatory T Cells Move in When Gliomas Say “I DO”
Authors: Choi Bryan D. , Fecci Peter E. , Sampson John H.
Published: April 2023

Abstract
Indoleamine 2,3-dioxygenase (IDO) is an enzyme with known immunosuppressive and tolerogenic effects in cancer. Mounting evidence has associated IDO expression with the induction of regulatory T cells (Treg) and malignant progression. IDO inhibition may therefore provide a promising therapeutic approach for glioblastoma, where the need for novel treatment is great. Clin Cancer Res; 18(22); 6086–8. ©2012 AACR.
Data from Pharmacokinetic and Pharmacodynamic Analysis of Circulating Biomarkers of Anti-NRP1, a Novel Antiangiogenesis Agent, in Two Phase I Trials in Patients with Advanced Solid Tumors
Authors: Xin Yan , Li Jessica , Wu Jenny , Kinard Rashell , Weekes Colin D. , Patnaik Amita , LoRusso Patricia , Brachmann Rainer , Tong Raymond K. , Yan Yibing , Watts Ryan , Bai Shuang , Hegde Priti S.
Published: April 2023

Abstract
Purpose: MNRP1685A is a monoclonal antibody to neuropilin-1 (NRP1). We evaluated blood-based pharmacodynamic biomarkers of MNRP1685A in two phase I studies to assess exposure/response relationships to inform target dose and regimen selection.

Experimental Design: The phase I studies evaluated escalating doses of MNRP1685A as a single agent or in combination with bevacizumab. Plasma placental growth factor (PlGF), VEGF, and circulating NRP1 (cNRP1) were evaluated at multiple time points using meso-scale discovery (MSD) assays and ELISA, respectively. Plasma PlGF was also measured in a phase I/II trial of bevacizumab in metastatic breast cancer (AVF0776). The association between PlGF and MNRP1685A dose was described by a sigmoid Emax model. cNRP1 and MNRP1685A PK profiles were described using a two-target quasi-steady state (QSS) model.

Results: A dose- and time-dependent increase in plasma PlGF and cNRP1 was observed in all patients treated with MNRP1685A. PK/PD analysis showed that bevacizumab and MNRP1685A had an additive effect in elevating PlGF. Predictions based on the two-target QSS model showed that the free drug concentration to maintain greater than 90% saturation of membrane NRP1 (mNRP1) and cNRP1 is about 8 μg/mL.

Conclusion: These data show that MNRP1685A inhibits the VEGF pathway in humans as assessed by an increase in plasma PlGF. MNRP1685A seems to enhance bevacizumab-mediated VEGF pathway blockade, as showed by an increase in the magnitude of PlGF elevation when combined with bevacizumab. PK/PD analysis of biomarkers in the phase I population allowed identification of doses at which apparent maximal pathway modulation was observed. Clin Cancer Res; 18(21); 6040–8. ©2012 AACR.
Data from NKX3.1 Haploinsufficiency Is Prognostic for Prostate Cancer Relapse following Surgery or Image-Guided Radiotherapy
Authors: Locke Jennifer A. , Zafarana Gaetano , Ishkanian Adrian S. , Milosevic Michael , Thoms John , Have Cherry L. , Malloff Chad A. , Lam Wan L. , Squire Jeremy A. , Pintilie Melania , Sykes Jenna , Ramnarine Varune Rohan , Meng Alice , Ahmed Omer , Jurisica Igor , van der Kwast Theo , Bristow Robert G.
Published: April 2023

Abstract
Background: Despite the use of prostate specific antigen (PSA), Gleason-score, and T-category as prognostic factors, up to 40% of patients with intermediate-risk prostate cancer will fail radical prostatectomy or precision image-guided radiotherapy (IGRT). Additional genetic prognosticators are needed to triage these patients toward intensified combination therapy with novel targeted therapeutics. We tested the role of the NKX3.1 gene as a determinant of treatment outcome given its reported roles in tumor initiating cell (TIC) renewal, the DNA damage response, and cooperation with c-MYC during prostate cancer progression.

Methods: Using high-resolution array comparative genomic hybridization (aCGH), we profiled the copy number alterations in TIC genes using tumor DNA from frozen needle biopsies derived from 126 intermediate-risk patients who underwent IGRT. These data were correlated to biochemical relapse-free rate (bRFR) by the Kaplan–Meier method and Cox proportional hazards models.

Results: A screen of the aCGH-IGRT data for TIC genes showed frequent copy number alterations for NKX3.1, PSCA, and c-MYC. NKX3.1 haploinsufficiency was associated with increased genomic instability independent of PSA, T-category, and Gleason-score. After adjusting for clinical factors in a multivariate model, NKX3.1 haploinsufficiency was associated with bRFR when tested alone (HR = 3.05, 95% CI: 1.46–6.39, P = 0.0030) or when combined with c-MYC gain (HR = 3.88, 95% CI: 1.78–8.49, P = 0.00067). A similar association was observed for patients following radical prostatectomy with a public aCGH database. NKX3.1 status was associated with positive biopsies post-IGRT and increased clonogen radioresistance in vitro.

Conclusions: Our results support the use of genomic predictors, such as NKX3.1 status, in needle biopsies for personalized approaches to prostate cancer management. Clin Cancer Res; 18(1); 308–16. ©2011 AACR.
Data from Decreased NK Cells in Patients with Head and Neck Cancer Determined in Archival DNA
Authors: Accomando William P. , Wiencke John K. , Houseman E. Andres , Butler Rondi A. , Zheng Shichun , Nelson Heather H. , Kelsey Karl T.
Published: April 2023

Abstract
Purpose: Natural killer (NK) cells are a key element of the innate immune system implicated in human cancer. To examine NK cell levels in archived bloods from a study of human head and neck squamous cell carcinoma (HNSCC), a new DNA-based quantification method was developed.

Experimental Design: NK cell-specific DNA methylation was identified by analyzing DNA methylation and mRNA array data from purified blood leukocyte subtypes (NK, T, B, monocytes, granulocytes), and confirmed via pyrosequencing and quantitative methylation specific PCR (qMSP). NK cell levels in archived whole blood DNA from 122 HNSCC patients and 122 controls were assessed by qMSP.

Results: Pyrosequencing and qMSP confirmed that a demethylated DNA region in NKp46 distinguishes NK cells from other leukocytes, and serves as a quantitative NK cell marker. Demethylation of NKp46 was significantly lower in HNSCC patient bloods compared with controls (P < 0.001). Individuals in the lowest NK tertile had over 5-fold risk of being a HNSCC case, controlling for age, gender, HPV16 status, cigarette smoking, alcohol consumption, and BMI (OR = 5.6, 95% CI, 2.0 to 17.4). Cases did not show differences in NKp46 demethylation based on tumor site or stage.

Conclusions: The results of this study indicate a significant depression in NK cells in HNSCC patients that is unrelated to exposures associated with the disease. DNA methylation biomarkers of NK cells represent an alternative to conventional flow cytometry that can be applied in a wide variety of clinical and epidemiologic settings including archival blood specimens. Clin Cancer Res; 18(22); 6147–54. ©2012 AACR.
Data from ATM Kinase Inhibition Preferentially Sensitizes p53-Mutant Glioma to Ionizing Radiation
Authors: Biddlestone-Thorpe Laura , Sajjad Muhammad , Rosenberg Elizabeth , Beckta Jason M. , Valerie Nicholas C.K. , Tokarz Mary , Adams Bret R. , Wagner Alison F. , Khalil Ashraf , Gilfor Donna , Golding Sarah E. , Deb Sumitra , Temesi David G. , Lau Alan , O'Connor Mark J. , Choe Kevin S. , Parada Luis F. , Lim Sang Kyun , Mukhopadhyay Nitai D. , Valerie Kristoffer
Published: April 2023

Abstract
Purpose: Glioblastoma multiforme (GBM) is the most lethal form of brain cancer with a median survival of only 12 to 15 months. Current standard treatment consists of surgery followed by chemoradiation. The poor survival of patients with GBM is due to aggressive tumor invasiveness, an inability to remove all tumor tissue, and an innate tumor chemo- and radioresistance. Ataxia–telangiectasia mutated (ATM) is an excellent target for radiosensitizing GBM because of its critical role in regulating the DNA damage response and p53, among other cellular processes. As a first step toward this goal, we recently showed that the novel ATM kinase inhibitor KU-60019 reduced migration, invasion, and growth, and potently radiosensitized human glioma cells in vitro.

Experimental Design: Using orthotopic xenograft models of GBM, we now show that KU-60019 is also an effective radiosensitizer in vivo. Human glioma cells expressing reporter genes for monitoring tumor growth and dispersal were grown intracranially, and KU-60019 was administered intratumorally by convection-enhanced delivery or osmotic pump.

Results: Our results show that the combined effect of KU-60019 and radiation significantly increased survival of mice 2- to 3-fold over controls. Importantly, we show that glioma with mutant p53 is much more sensitive to KU-60019 radiosensitization than genetically matched wild-type glioma.

Conclusions: Taken together, our results suggest that an ATM kinase inhibitor may be an effective radiosensitizer and adjuvant therapy for patients with mutant p53 brain cancers. Clin Cancer Res; 19(12); 3189–200. ©2013 AACR.
Data from A 26-Gene Hypoxia Signature Predicts Benefit from Hypoxia-Modifying Therapy in Laryngeal Cancer but Not Bladder Cancer
Authors: Eustace Amanda , Mani Navin , Span Paul N. , Irlam Joely J. , Taylor Janet , Betts Guy N.J. , Denley Helen , Miller Crispin J. , Homer Jarrod J. , Rojas Ana M. , Hoskin Peter J. , Buffa Francesca M. , Harris Adrian L. , Kaanders Johannes H.A.M. , West Catharine M.L.
Published: April 2023

Abstract
Purpose: Tumor hypoxia is associated with a poor prognosis, hypoxia modification improves outcome, and hypoxic status predicts benefit from treatment. Yet, there is no universal measure of clinical hypoxia. The aim of this study was to investigate whether a 26-gene hypoxia signature predicted benefit from hypoxia-modifying treatment in both cancer types.

Experimental Design: Samples were available from 157 T2–T4 laryngeal cancer and 185 T1–T4a bladder cancer patients enrolled on the accelerated radiotherapy with carbogen and nicotinamide (ARCON) and bladder carbogen nicotinamide (BCON) phase III randomized trials of radiotherapy alone or with carbogen and nicotinamide (CON) respectively. Customized TaqMan low density arrays (TLDA) were used to assess expression of the 26-gene signature using quantitative real-time PCR. The median expression of the 26 genes was used to derive a hypoxia score (HS). Patients were categorized as TLDA-HS low (≤median) or TLDA-HS high (>median). The primary outcome measures were regional control (RC; ARCON) and overall survival (BCON).

Results: Laryngeal tumors categorized as TLDA-HS high showed greater benefit from ARCON than TLDA-HS low tumors. Five-year RC was 81% (radiotherapy alone) versus 100% (CON) for TLDA-HS high (P = 0.009). For TLDA-HS low, 5-year RC was 91% (radiotherapy alone) versus 90% (CON; P = 0.90). TLDA-HS did not predict benefit from CON in bladder cancer.

Conclusion: The 26-gene hypoxia signature predicts benefit from hypoxia-modifying treatment in laryngeal cancer. These findings will be evaluated in a prospective clinical trial. Clin Cancer Res; 19(17); 4879–88. ©2013 AACR.
Data from Decitabine Induces Delayed Reactive Oxygen Species (ROS) Accumulation in Leukemia Cells and Induces the Expression of ROS Generating Enzymes
Authors: Fandy Tamer E. , Jiemjit Anchalee , Thakar Manjusha , Rhoden Paulette , Suarez Lauren , Gore Steven D.
Published: April 2023

Abstract
Purpose: Azanucleoside DNA methyltransferase (DNMT) inhibitors are currently approved by the U.S. Food and Drug Administration for treatment of myelodysplastic syndrome. The relative contributions of DNMT inhibition and other off-target effects to their clinical efficacy remain unclear. Data correlating DNA methylation reversal and clinical response have been conflicting. Consequently, it is necessary to investigate so-called off-target effects and their impact on cell survival and differentiation.

Experimental Design: Flow cytometry was used for cell cycle, apoptosis, and reactive oxygen species (ROS) accumulation analysis. Gene expression analysis was performed using real-time PCR. DNA methylation was detected by methylation-specific PCR. Mitochondrial membrane potential was analyzed using JC-1 dye staining. Western blotting was used for quantitative protein expression analysis.

Results: 5-Aza-2′-deoxycytidine (DAC) induced cell-cycle arrest and apoptosis in leukemia cells. p53 expression was dispensable for DAC-induced apoptosis. DAC induced delayed ROS accumulation in leukemia cells but not in solid tumor cells and p53 expression was dispensable for ROS increase. ROS increase was deoxycytidine kinase dependent, indicating that incorporation of DAC into nuclear DNA is required for ROS generation. ROS accumulation by DAC was caspase-independent and mediated the dissipation of the mitochondrial membrane potential. Concordantly, ROS scavengers diminished DAC-induced apoptosis. DAC induced the expression of different NADPH oxidase isoforms and upregulated Nox4 protein expression in an ATM-dependent manner, indicating the involvement of DNA damage signaling in Nox4 upregulation.

Conclusion: These data highlight the importance of mechanisms other than DNA cytosine demethylation in modulating gene expression and suggest investigating the relevance of ROS accumulation to the clinical activity of DAC. Clin Cancer Res; 20(5); 1249–58. ©2014 AACR.
Data from Colon Cancer Cells Escape 5FU Chemotherapy-Induced Cell Death by Entering Stemness and Quiescence Associated with the c-Yes/YAP Axis
Authors: Touil Yasmine , Igoudjil Wassila , Corvaisier Matthieu , Dessein Anne-Frédérique , Vandomme Jérôme , Monté Didier , Stechly Laurence , Skrypek Nicolas , Langlois Carole , Grard Georges , Millet Guillaume , Leteurtre Emmanuelle , Dumont Patrick , Truant Stéphanie , Pruvot François-René , Hebbar Mohamed , Fan Fan , Ellis Lee M. , Formstecher Pierre , Van Seuningen Isabelle , Gespach Christian , Polakowska Renata , Huet Guillemette
Published: April 2023

Abstract
Purpose: Metastasis and drug resistance are the major limitations in the survival and management of patients with cancer. This study aimed to identify the mechanisms underlying HT29 colon cancer cell chemoresistance acquired after sequential exposure to 5-fluorouracil (5FU), a classical anticancer drug for treatment of epithelial solid tumors. We examined its clinical relevance in a cohort of patients with colon cancer with liver metastases after 5FU-based neoadjuvant chemotherapy and surgery.

Results: We show that a clonal 5F31 cell population, resistant to 1 μmol/L 5FU, express a typical cancer stem cell–like phenotype and enter into a reversible quiescent G0 state upon reexposure to higher 5FU concentrations. These quiescent cells overexpressed the tyrosine kinase c-Yes that became activated and membrane-associated upon 5FU exposure. This enhanced signaling pathway induced the dissociation of the Yes/YAP (Yes-associated protein) molecular complex and depleted nuclear YAP levels. Consistently, YES1 silencing decreased nuclear YAP accumulation and induced cellular quiescence in 5F31 cells cultured in 5FU-free medium. Importantly, YES1 and YAP transcript levels were higher in liver metastases of patients with colon cancer after 5FU-based neoadjuvant chemotherapy. Moreover, the YES1 and YAP transcript levels positively correlated with colon cancer relapse and shorter patient survival (P < 0.05 and P < 0.025, respectively).

Conclusions: We identified c-Yes and YAP as potential molecular targets to eradicate quiescent cancer cells and dormant micrometastases during 5FU chemotherapy and resistance and as predictive survival markers for colon cancer. Clin Cancer Res; 20(4); 837–46. ©2013 AACR.
Data from A Peptide-Based Positron Emission Tomography Probe for In Vivo Detection of Caspase Activity in Apoptotic Cells
Authors: Hight Matthew R. , Cheung Yiu-Yin , Nickels Michael L. , Dawson Eric S. , Zhao Ping , Saleh Samir , Buck Jason R. , Tang Dewei , Washington M. Kay , Coffey Robert J. , Manning H. Charles
Published: April 2023

Abstract
Purpose: Apoptosis, or programmed cell death, can be leveraged as a surrogate measure of response to therapeutic interventions in medicine. Cysteine aspartic acid–specific proteases, or caspases, are essential determinants of apoptosis signaling cascades and represent promising targets for molecular imaging. Here, we report development and in vivo validation of [18F]4-fluorobenzylcarbonyl–Val–Ala–Asp(OMe)–fluoromethylketone ([18F]FB-VAD-FMK), a novel peptide-based molecular probe suitable for quantification of caspase activity in vivo using positron emission tomography (PET).

Experimental Design: Supported by molecular modeling studies and subsequent in vitro assays suggesting probe feasibility, the labeled pan-caspase inhibitory peptide, [18F]FB-VAD-FMK, was produced in high radiochemical yield and purity using a simple two-step, radiofluorination. The biodistribution of [18F]FB-VAD-FMK in normal tissue and its efficacy to predict response to molecularly targeted therapy in tumors was evaluated using microPET imaging of mouse models of human colorectal cancer.

Results: Accumulation of [18F]FB-VAD-FMK was found to agree with elevated caspase-3 activity in response to Aurora B kinase inhibition as well as a multidrug regimen that combined an inhibitor of mutant BRAF and a dual PI3K/mTOR inhibitor in V600EBRAF colon cancer. In the latter setting, [18F]FB-VAD-FMK PET was also elevated in the tumors of cohorts that exhibited reduction in size.

Conclusions: These studies illuminate [18F]FB-VAD-FMK as a promising PET imaging probe to detect apoptosis in tumors and as a novel, potentially translatable biomarker for predicting response to personalized medicine. Clin Cancer Res; 20(8); 2126–35. ©2014 AACR.
Data from Molecular Imaging of Death Receptor 5 Occupancy and Saturation Kinetics In Vivo by Humanized Monoclonal Antibody CS-1008
Authors: Burvenich Ingrid J.G. , Lee Fook T. , Cartwright Glenn A. , O'Keefe Graeme J. , Makris Dahna , Cao Diana , Gong Sylvia , Chueh Anderly C. , Mariadason John M. , Brechbiel Martin W. , Beckman Robert A. , Fujiwara Kosaku , von Roemeling Reinhard , Scott Andrew M.
Published: April 2023

Abstract
Purpose: CS-1008 (tigatuzumab; phase I/II), an antihuman death receptor 5 (DR5) agonist, induces apoptosis and has cytotoxic activity against human cancer cell lines. This study reports on the preclinical validation of 111In-labeled anti-DR5 humanized antibody CS-1008 as a diagnostic tool to study the DR5 occupancy in patients with cancer and establish dose ranges for receptor saturation kinetics in vivo.

Experimental Design: CS-1008 was radiolabeled and characterized for DR5 binding and labeling efficiency on TRAIL-sensitive DR5–positive colorectal cancer cells (COLO 205 and WiDr). Pharmacokinetic and biodistribution studies were conducted in BALB/c nu/nu mice bearing COLO 205, WiDr, or DR5-negative CT26 colon tumors. Planar gamma camera imaging and computerized tomography (CT) images were obtained to study receptor occupancy in vivo.

Results: Scatchard analysis showed high and specific binding affinity (Kd, 1.05 ± 0.12 nmol/L) of 111In-labeled CS-1008. 111In-labeled CS-1008 was specifically taken up in mice bearing COLO 205 and WiDr tumors with prolonged tumor retention (26.25 ± 2.85%ID/g vs. 12.20 ± 2.24 at 168 hours post injection; n = 5, SD), and uptake correlated both with DR5 expression on tumor cells and antitumor activity. DR5 saturation was shown in vivo via both biodistribution studies and planar gamma camera imaging/CT imaging of 111In-labeled CS-1008. Saturation of DR5 corresponded to maximal in vivo antitumor efficacy.

Conclusions: Imaging of DR5 receptor occupancy in vivo correlates with tumor concentration and in vivo efficacy, and is a novel molecular imaging technique that can be used to determine receptor occupancy and effective dose levels of DR5 agonist antibodies in the clinic. Clin Cancer Res; 19(21); 5984–93. ©2013 AACR.
Data from A Collagen-Remodeling Gene Signature Regulated by TGF-β Signaling Is Associated with Metastasis and Poor Survival in Serous Ovarian Cancer
Authors: Cheon Dong-Joo , Tong Yunguang , Sim Myung-Shin , Dering Judy , Berel Dror , Cui Xiaojiang , Lester Jenny , Beach Jessica A. , Tighiouart Mourad , Walts Ann E. , Karlan Beth Y. , Orsulic Sandra
Published: April 2023

Abstract
Purpose: To elucidate molecular pathways contributing to metastatic cancer progression and poor clinical outcome in serous ovarian cancer.

Experimental Design: Poor survival signatures from three different serous ovarian cancer datasets were compared and a common set of genes was identified. The predictive value of this gene signature was validated in independent datasets. The expression of the signature genes was evaluated in primary, metastatic, and/or recurrent cancers using quantitative PCR and in situ hybridization. Alterations in gene expression by TGF-β1 and functional consequences of loss of COL11A1 were evaluated using pharmacologic and knockdown approaches, respectively.

Results: We identified and validated a 10-gene signature (AEBP1, COL11A1, COL5A1, COL6A2, LOX, POSTN, SNAI2, THBS2, TIMP3, and VCAN) that is associated with poor overall survival (OS) in patients with high-grade serous ovarian cancer. The signature genes encode extracellular matrix proteins involved in collagen remodeling. Expression of the signature genes is regulated by TGF-β1 signaling and is enriched in metastases in comparison with primary ovarian tumors. We demonstrate that levels of COL11A1, one of the signature genes, continuously increase during ovarian cancer disease progression, with the highest expression in recurrent metastases. Knockdown of COL11A1 decreases in vitro cell migration, invasion, and tumor progression in mice.

Conclusion: Our findings suggest that collagen-remodeling genes regulated by TGF-β1 signaling promote metastasis and contribute to poor OS in patients with serous ovarian cancer. Our 10-gene signature has both predictive value and biologic relevance and thus may be useful as a therapeutic target. Clin Cancer Res; 20(3); 711–23. ©2013 AACR.
Data from The G-Protein–Coupled Receptor CLR Is Upregulated in an Autocrine Loop with Adrenomedullin in Clear Cell Renal Cell Carcinoma and Associated with Poor Prognosis
Authors: Nikitenko Leonid L. , Leek Russell , Henderson Stephen , Pillay Nischalan , Turley Helen , Generali Daniele , Gunningham Sarah , Morrin Helen R. , Pellagatti Andrea , Rees Margaret C.P. , Harris Adrian L. , Fox Stephen B.
Published: April 2023

Abstract
Purpose: The G-protein–coupled receptor (GPCR) calcitonin receptor-like receptor (CLR) and its ligand peptide adrenomedullin (encoded by ADM gene) are implicated in tumor angiogenesis in mouse models but poorly defined in human cancers. We therefore investigated the diagnostic/prognostic use for CLR in human tumor types that may rely on adrenomedullin signaling and in clear cell renal cell carcinoma (RCC), a highly vascular tumor, in particular.

Experimental Design:In silico gene expression mRNA profiling microarray study (n = 168 tumors) and cancer profiling cDNA array hybridization (n = 241 pairs of patient-matched tumor/normal tissue samples) were carried out to analyze ADM mRNA expression in 13 tumor types. Immunohistochemistry on tissue microarrays containing patient-matched renal tumor/normal tissues (n = 87 pairs) was conducted to study CLR expression and its association with clinicopathologic parameters and disease outcome.

Results:ADM expression was significantly upregulated only in RCC and endometrial adenocarcinoma compared with normal tissue counterparts (P < 0.01). CLR was localized in tumor cells and vessels in RCC and upregulated as compared with patient-matched normal control kidney (P < 0.001). Higher CLR expression was found in advanced stages (P < 0.05), correlated with high tumor grade (P < 0.01) and conferred shorter overall survival (P < 0.01).

Conclusions: In human tissues ADM expression is upregulated in cancer type–specific manner, implicating potential role for adrenomedullin signaling in particular in RCC, where CLR localization suggests autocrine/paracrine mode for adrenomedullin action within the tumor microenvironment. Our findings reveal previously unrecognized CLR upregulation in an autocrine loop with adrenomedullin in RCC with potential application for this GPCR as a target for future functional studies and drug development. Clin Cancer Res; 19(20); 5740–8. ©2013 AACR.
Data from In Situ Tumor PD-L1 mRNA Expression Is Associated with Increased TILs and Better Outcome in Breast Carcinomas
Authors: Schalper Kurt A. , Velcheti Vamsidhar , Carvajal Daniel , Wimberly Hallie , Brown Jason , Pusztai Lajos , Rimm David L.
Published: April 2023

Abstract
Purpose: Blockade of the PD-1/PD-L1 axis emerged as a promising new therapeutic option for cancer that has resulted in lasting responses in metastatic renal, lung carcinomas, and melanomas. Tumor PD-L1 protein expression may predict response to drugs targeting this pathway. Measurement of PD-L1 protein is limited by the lack of standardized immunohistochemical methods and variable performance of antibodies. Our goal was to correlate PD-L1 mRNA expression with clinical variables in primary breast carcinomas.

Experimental Design: The fluorescent RNAscope paired-primer assay was used to quantify in situ PD-L1 mRNA levels in 636 stage I–III breast carcinomas on two sets of tissue microarrays [YTMA128 (n = 238) and YTMA201 (n = 398)]. Tumor-infiltrating lymphocytes (TIL) were assessed by hematoxylin/eosin stain and quantitative fluorescence.

Results: On YTMA128 and YTMA201, 55.7% and 59.5% of cases showed PD-L1 mRNA expression, respectively. Higher PD-L1 mRNA expression was significantly associated with increased TILs (P = 0.04) but not with other clinical variables. Elevated TILs (scores 2 and 3+) occurred in 16.5% on YTMA128 and 14.8% on YTMA201 and was associated with estrogen receptor–negative status (P = 0.01 on YTMA128 and 0.0001 on YTMA201). PD-L1 mRNA expression was associated with longer recurrence-free survival (log-rank P = 0.01), which remained significant in multivariate analysis including age, tumor size, histologic grade, nodal metastasis, hormone receptor, HER2 status, and the extent of TILs (HR, 0.268; CI, 0.099–0.721; P = 0.009).

Conclusions: PD-L1 mRNA expression is identified in nearly 60% of breast tumors and it is associated with increased TILs and improved recurrence-free survival. These observations support the evaluation of PD-1/PD-L1–targeted therapies in breast cancer. Clin Cancer Res; 20(10); 2773–82. ©2014 AACR.
Data from Toward Prediction of Efficacy of Chemotherapy: A Proof of Concept Study in Lung Cancer Patients Using [11C]docetaxel and Positron Emission Tomography
Authors: van der Veldt Astrid A.M. , Lubberink Mark , Mathijssen Ron H.J. , Loos Walter J. , Herder Gerarda J.M. , Greuter Henri N. , Comans Emile F.I. , Rutten Hugo B. , Eriksson Jonas , Windhorst Albert D. , Hendrikse N. Harry , Postmus Pieter E. , Smit Egbert F. , Lammertsma Adriaan A.
Published: April 2023

Abstract
Purpose: Pharmacokinetics of docetaxel can be measured in vivo using positron emission tomography (PET) and a microdose of radiolabeled docetaxel ([11C]docetaxel). The objective of this study was to investigate whether a [11C]docetaxel PET microdosing study could predict tumor uptake of therapeutic doses of docetaxel.

Experimental Design: Docetaxel-naïve lung cancer patients underwent 2 [11C]docetaxel PET scans; one after bolus injection of [11C]docetaxel and another during combined infusion of [11C]docetaxel and a therapeutic dose of docetaxel (75 mg·m−2). Compartmental and spectral analyses were used to quantify [11C]docetaxel tumor kinetics. [11C]docetaxel PET measurements were used to estimate the area under the curve (AUC) of docetaxel in tumors. Tumor response was evaluated using computed tomography scans.

Results: Net rates of influx (Ki) of [11C]docetaxel in tumors were comparable during microdosing and therapeutic scans. [11C]docetaxel AUCTumor during the therapeutic scan could be predicted reliably using an impulse response function derived from the microdosing scan together with the plasma curve of [11C]docetaxel during the therapeutic scan. At 90 minutes, the accumulated amount of docetaxel in tumors was less than 1% of the total infused dose of docetaxel. [11C]docetaxel Ki derived from the microdosing scan correlated with AUCTumor of docetaxel (Spearman ρ = 0.715; P = 0.004) during the therapeutic scan and with tumor response to docetaxel therapy (Spearman ρ = −0.800; P = 0.010).

Conclusions: Microdosing data of [11C]docetaxel PET can be used to predict tumor uptake of docetaxel during chemotherapy. The present study provides a framework for investigating the PET microdosing concept for radiolabeled anticancer drugs in patients. Clin Cancer Res; 19(15); 4163–73. ©2013 AACR.
Data from Prognostic Relevance of Circulating Tumor Cells in Blood and Disseminated Tumor Cells in Bone Marrow of Patients with Squamous Cell Carcinoma of the Oral Cavity
Authors: Gröbe Alexander , Blessmann Marco , Hanken Henning , Friedrich Reinhard E. , Schön Gerhard , Wikner Johannes , Effenberger Katharina E. , Kluwe Lan , Heiland Max , Pantel Klaus , Riethdorf Sabine
Published: April 2023

Abstract
Purpose: Current staging methods for squamous cell carcinomas (SCC) of the oral cavity (OSCC) need to be improved to predict the risk of individual patients. Because hematogenous tumor cell dissemination is a key event in tumor progression, we assessed the prognostic significance of disseminated tumor cells (DTC) in bone marrow and circulating tumor cells (CTC) in peripheral blood from patients with OSCC.

Experimental Design: From 110 patients with OSCC, tumors were surgically resected (R0) without neoadjuvant therapy. The CellSearch system was used to enumerate CTCs. Bone marrow was aspirated from the iliac crest, and mononuclear cells (MNC) were enriched by Ficoll density gradient centrifugation. To detect DTCs, MNCs were immunostained with the pan-keratin antibody A45-B/B3. Results were correlated with clinicopathologic parameters and clinical outcome such as recurrence and death during follow-up time (mean 916 days).

Results: Ten of 80 patients (12.5%) harbored CTCs in peripheral blood, whereas in 18 of 90 patients (20.0%) DTCs in bone marrow could be detected. Surprisingly, in only 2 patients (1.8%) CTCs and DTCs were detected simultaneously. Significant correlations could be found for CTCs and tumor size (P = 0.04), nodal status and DTCs (P = 0.02), and distant metastasis with CTCs (P = 0.004) and DTCs (P = 0.005). Univariate and multivariate analyses revealed that CTCs and DTCs were significant and independent predictors of recurrence-free survival (P < 0.001).

Conclusions: Both DTCs and CTCs are independent prognostic markers in patients with OSCC, predicting relapse with higher sensitivity at various disease stages than routine staging procedures. Bone marrow might be an interesting target organ for future therapeutic interventions. Clin Cancer Res; 20(2); 425–33. ©2013 AACR.
Data from Targeting Treatment-Resistant Breast Cancer Stem Cells with FKBPL and Its Peptide Derivative, AD-01, via the CD44 Pathway
Authors: McClements Lana , Yakkundi Anita , Papaspyropoulos Angelos , Harrison Hannah , Ablett Matthew P. , Jithesh Puthen V. , McKeen Hayley D. , Bennett Rachel , Donley Christopher , Kissenpfennig Adrien , McIntosh Stuart , McCarthy Helen O. , O'Neill Eric , Clarke Robert B. , Robson Tracy
Published: April 2023

Abstract
Purpose: FK506-binding protein like (FKBPL) and its peptide derivative, AD-01, have already shown tumor growth inhibition and CD44-dependent antiangiogenic activity. Here, we explore the ability of AD-01 to target CD44-positive breast cancer stem cells (BCSC).

Experimental Design: Mammosphere assays and flow cytometry were used to analyze the effect of FKBPL overexpression/knockdown and AD-01 treatment ± other anticancer agents on BCSCs using breast cancer cell lines (MCF-7/MDA-231/ZR-75), primary patient samples, and xenografts. Delays in tumor initiation were evaluated in vivo. The anti–stem cell mechanisms were determined using clonogenic assays, quantitative PCR (qPCR), and immunofluorescence.

Results: AD-01 treatment was highly effective at inhibiting the BCSC population by reducing mammosphere-forming efficiency and ESA+/CD44+/CD24− or aldehyde dehydrogenase (ALDH)+ cell subpopulations in vitro and tumor initiation in vivo. The ability of AD-01 to inhibit the self-renewal capacity of BCSCs was confirmed; mammospheres were completely eradicated by the third generation. The mechanism seems to be due to AD-01–mediated BCSC differentiation shown by a significant decrease in the number of holoclones and an associated increase in meroclones/paraclones; the stem cell markers, Nanog, Oct4, and Sox2, were also significantly reduced. Furthermore, we showed additive inhibitory effects when AD-01 was combined with the Notch inhibitor, DAPT. AD-01 was also able to abrogate a chemo- and radiotherapy-induced enrichment in BCSCs. Finally, FKBPL knockdown led to an increase in Nanog/Oct4/Sox2 and an increase in BCSCs, highlighting a role for endogenous FKBPL in stem cell signaling.

Conclusions: AD-01 has dual antiangiogenic and anti-BCSC activity, which will be advantageous as this agent enters clinical trial. Clin Cancer Res; 19(14); 3881–93. ©2013 AACR.
Data from Preclinical Efficacy of the Anti-Hepatocyte Growth Factor Antibody Ficlatuzumab in a Mouse Brain Orthotopic Glioma Model Evaluated by Bioluminescence, PET, and MRI
Authors: Mittra Erik S. , Fan-Minogue Hua , Lin Frank I. , Karamchandani Jason , Sriram Venkataraman , Han May , Gambhir Sanjiv S.
Published: April 2023

Abstract
Purpose: Ficlatuzumab is a novel therapeutic agent targeting the hepatocyte growth factor (HGF)/c-MET pathway. We summarize extensive preclinical work using this agent in a mouse brain orthotopic model of glioblastoma.

Experimental Design: Sequential experiments were done using eight- to nine-week-old nude mice injected with 3 × 105 U87 MG (glioblastoma) cells into the brain. Evaluation of ficlatuzumab dose response for this brain tumor model and comparison of its response to ficlatuzumab and to temozolamide were conducted first. Subsequently, various small-animal imaging modalities, including bioluminescence imaging (BLI), positron emission tomography (PET), and MRI, were used with a U87 MG-Luc 2 stable cell line, with and without the use of ficlatuzumab, to evaluate the ability to noninvasively assess tumor growth and response to therapy. ANOVA was conducted to evaluate for significant differences in the response.

Results: There was a survival benefit with ficlatuzumab alone or in combination with temozolamide. BLI was more sensitive than PET in detecting tumor cells. Fluoro-D-thymidine (FLT) PET provided a better signal-to-background ratio than 2[18F]fluoro-2-deoxy-d-glucose (FDG) PET. In addition, both BLI and FLT PET showed significant changes over time in the control group as well as with response to therapy. MRI does not disclose any time-dependent change. Also, the MRI results showed a temporal delay in comparison to the BLI and FLT PET findings, showing similar results one drug cycle later.

Conclusions: Targeting the HGF/c-MET pathway with the novel agent ficlatuzumab appears promising for the treatment of glioblastoma. Various clinically applicable imaging modalities including FLT, PET, and MRI provide reliable ways of assessing tumor growth and response to therapy. Given the clinical applicability of these findings, future studies on patients with glioblastoma may be appropriate. Clin Cancer Res; 19(20); 5711–21. ©2013 AACR.
Data from Progression-Free Survival as a Surrogate Endpoint for Median Overall Survival in Metastatic Colorectal Cancer: Literature-Based Analysis from 50 Randomized First-Line Trials
Authors: Giessen Clemens , Laubender Ruediger Paul , Ankerst Donna Pauler , Stintzing Sebastian , Modest Dominik Paul , Mansmann Ulrich , Heinemann Volker
Published: April 2023

Abstract
Purpose: To evaluate progression-free survival (PFS) as a potential surrogate endpoint (SEP) for overall survival (OS) in metastatic colorectal cancer (mCRC) with a focus on applicability to trials containing targeted therapy with anti-VEGF- or anti-EGF receptor (EGFR)–directed monoclonal antibodies.

Experimental Design: A systematic literature search of randomized trials of first-line chemotherapy for mCRC reported from January 2000 to January 2012 was conducted. Adjusted weighted linear regression was used to calculate correlations within PFS and OS (endpoints; REP) and between treatment effects on PFS and on OS (treatment effects; RTE).

Results: Fifty trials reflecting 22,736 patients met the inclusion criteria. Correlation between treatment effects on PFS and OS and between the endpoints PFS and OS was high across all studies (RTE = 0.87, REP = 0.86). This was also observed in chemotherapy-only trials (RTE = 0.93, REP = 0.81) but less so for trials containing monoclonal antibodies (RTE = 0.47; REP = 0.52). Limiting the analysis to bevacizumab-based studies (11 trials, 3,310 patients) again yielded high correlations between treatment effects on PFS and on OS (RTE = 0.84), whereas correlation within PFS and OS was low (REP = 0.45). In 7 trials (1,335 patients) investigating cetuximab- or panitumumab-based studies, contrasting correlations with very wide confidence intervals were observed (RTE = 0.28; REP = 0.96).

Conclusions: PFS showed consistently high correlation with OS of an order that would justify its use as an SEP in chemotherapy regimens. For validation of surrogacy in anti-VEGF and anti-EGFR–directed therapies, further research and a larger set of trials is needed. Clin Cancer Res; 19(1); 225–35. ©2012 AACR.