Publications by authors named "Andrew J Brenner"

42 Publications

Differentiation of Brain Tumor Microvasculature From Normal Vessels Using Optical Coherence Angiography.

Lasers Surg Med 2021 Jun 15. Epub 2021 Jun 15.

Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA.

Background And Objectives: Despite rapid advances and discoveries in medical imaging, monitoring therapeutic efficacy for malignant gliomas and monitoring tumor vasculature remains problematic. The purpose of this study is to utilize optical coherence angiography for vasculature characterization inside and surrounding brain tumors in a murine xenograft brain tumor model. Features included in our analysis include fractional blood volume, vessel tortuosity, diameter, orientation, and directionality.

Study Design/materials And Methods: In this study, five tumorous mice models at 4 weeks of age were imaged. Human glioblastoma cells were injected into the brain and allowed to grow for 4 weeks and then imaged using optical coherence tomography.

Results: Results suggest that blood vessels outside the tumor contain a greater fractional blood volume as compared with vessels inside the tumor. Vessels inside the tumor are more tortuous as compared with those outside the tumor. Results indicate that vessels near the tumor margin are directed inward towards the tumor while normal vessels show a more random orientation.

Conclusion: Quantification of vascular microenvironments in brain gliomas can provide functional vascular parameters to aid various diagnostic and therapeutic studies. © 2021 Wiley Periodicals LLC.
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http://dx.doi.org/10.1002/lsm.23446DOI Listing
June 2021

Patient specific, imaging-informed modeling of rhenium-186 nanoliposome delivery via convection-enhanced delivery in glioblastoma multiforme.

Biomed Phys Eng Express 2021 May 28;7(4). Epub 2021 May 28.

Biomedical Engineering, The University of Texas at Austin, Austin, Texas, United States of America.

Convection-enhanced delivery of rhenium-186 (Re)-nanoliposomes is a promising approach to provide precise delivery of large localized doses of radiation for patients with recurrent glioblastoma multiforme. Current approaches for treatment planning utilizing convection-enhanced delivery are designed for small molecule drugs and not for larger particles such asRe-nanoliposomes. To enable the treatment planning forRe-nanoliposomes delivery, we have developed a computational fluid dynamics approach to predict the distribution of nanoliposomes for individual patients. In this work, we construct, calibrate, and validate a family of computational fluid dynamics models to predict the spatio-temporal distribution ofRe-nanoliposomes within the brain, utilizing patient-specific pre-operative magnetic resonance imaging (MRI) to assign material properties for an advection-diffusion transport model. The model family is calibrated to single photon emission computed tomography (SPECT) images acquired during and after the infusion ofRe-nanoliposomes for five patients enrolled in a Phase I/II trial (NCT Number NCT01906385), and is validated using a leave-one-out bootstrapping methodology for predicting the final distribution of the particles. After calibration, our models are capable of predicting the mid-delivery and final spatial distribution ofRe-nanoliposomes with a Dice value of 0.69 ± 0.18 and a concordance correlation coefficient of 0.88 ± 0.12 (mean ± 95% confidence interval), using only the patient-specific, pre-operative MRI data, and calibrated model parameters from prior patients. These results demonstrate a proof-of-concept for a patient-specific modeling framework, which predicts the spatial distribution of nanoparticles. Further development of this approach could enable optimizing catheter placement for future studies employing convection-enhanced delivery.
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http://dx.doi.org/10.1088/2057-1976/ac02a6DOI Listing
May 2021

FASN inhibition as a potential treatment for endocrine-resistant breast cancer.

Breast Cancer Res Treat 2021 Jun 24;187(2):375-386. Epub 2021 Apr 24.

UT Health San Antonio MD Anderson Cancer Center, San Antonio, TX, USA.

Purpose: The majority of breast cancers are estrogen receptor (ERα) positive making endocrine therapy a mainstay for these patients. Unfortunately, resistance to endocrine therapy is a common occurrence. Fatty acid synthase (FASN) is a key enzyme in lipid biosynthesis and its expression is commensurate with tumor grade and resistance to numerous therapies.

Methods: The effect of the FASN inhibitor TVB-3166 on ERα expression and cell growth was characterized in tamoxifen-resistant cell lines, xenografts, and patient explants. Subcellular localization of ERα was assessed using subcellular fractionations. Palmitoylation and ubiquitination of ERα were assessed by immunoprecipitation. ERα and p-eIF2α protein levels were analyzed by Western blotting after treatment with TVB-3166 with or without the addition of palmitate or BAPTA.

Results: TVB-3166 treatment leads to a marked inhibition of proliferation in tamoxifen-resistant cells compared to the parental cells. Additionally, TVB-3166 significantly inhibited tamoxifen-resistant breast tumor growth in mice and decreased proliferation of primary tumor explants compared to untreated controls. FASN inhibition significantly reduced ERα levels most prominently in endocrine-resistant cells and altered its subcellular localization. Furthermore, we showed that the reduction of ERα expression upon TVB-3166 treatment is mediated through the induction of endoplasmic reticulum stress.

Conclusion: Our preclinical data provide evidence that FASN inhibition by TVB-3166 presents a promising therapeutic strategy for the treatment of endocrine-resistant breast cancer. Further clinical development of FASN inhibitors for endocrine-resistant breast cancer should be considered.
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http://dx.doi.org/10.1007/s10549-021-06231-6DOI Listing
June 2021

Assessment of tumor hypoxia and perfusion in recurrent glioblastoma following bevacizumab failure using MRI and F-FMISO PET.

Sci Rep 2021 Apr 7;11(1):7632. Epub 2021 Apr 7.

Mays Cancer Center, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229-3900, USA.

Tumoral hypoxia correlates with worse outcomes in glioblastoma (GBM). While bevacizumab is routinely used to treat recurrent GBM, it may exacerbate hypoxia. Evofosfamide is a hypoxia-targeting prodrug being tested for recurrent GBM. To characterize resistance to bevacizumab and identify those with recurrent GBM who may benefit from evofosfamide, we ascertained MRI features and hypoxia in patients with GBM progression receiving both agents. Thirty-three patients with recurrent GBM refractory to bevacizumab were enrolled. Patients underwent MR and F-FMISO PET imaging at baseline and 28 days. Tumor volumes were determined, MRI and F-FMISO PET-derived parameters calculated, and Spearman correlations between parameters assessed. Progression-free survival decreased significantly with hypoxic volume [hazard ratio (HR) = 1.67, 95% confidence interval (CI) 1.14 to 2.46, P = 0.009] and increased significantly with time to the maximum value of the residue (Tmax) (HR = 0.54, 95% CI 0.34 to 0.88, P = 0.01). Overall survival decreased significantly with hypoxic volume (HR = 1.71, 95% CI 1.12 to 12.61, p = 0.01), standardized relative cerebral blood volume (srCBV) (HR = 1.61, 95% CI 1.09 to 2.38, p = 0.02), and increased significantly with Tmax (HR = 0.31, 95% CI 0.15 to 0.62, p < 0.001). Decreases in hypoxic volume correlated with longer overall and progression-free survival, and increases correlated with shorter overall and progression-free survival. Hypoxic volume and volume ratio were positively correlated (r = 0.77, P < 0.0001), as were hypoxia volume and T1 enhancing tumor volume (r = 0.75, P < 0.0001). Hypoxia is a key biomarker in patients with bevacizumab-refractory GBM. Hypoxia and srCBV were inversely correlated with patient outcomes. These radiographic features may be useful in evaluating treatment and guiding treatment considerations.
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http://dx.doi.org/10.1038/s41598-021-84331-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8027395PMC
April 2021

Phase 2 trial of hypoxia activated evofosfamide (TH302) for treatment of recurrent bevacizumab-refractory glioblastoma.

Sci Rep 2021 Jan 27;11(1):2306. Epub 2021 Jan 27.

Dana Farber Cancer Institute, Boston, MA, USA.

Evofosfamide (Evo or TH302) is a hypoxia-activated prodrug which is reduced leading to the release of alkylating agent bromo-isophosphoramide mustard, which has shown safety and signals of efficacy in a prior phase 1 study in recurrent glioblastoma. We performed a dual center single-arm Phase II study to expand on the safety and efficacy of Evo plus bevacizumab in bevacizumab refractory glioblastoma. 33 patients with bevacizumab refractory GBM received Evo 670 mg/m in combination with Bevacizumab 10 mg/kg IV every 2 weeks. Assessments included adverse events, response, and survival. Median age of patients was 47 (range 19-76) and 24 (69%) were male. At the time of study entry, 9 (26%) had ongoing corticosteroid use. ECOG performance status was 0 or 1 in 83% of patients. Patients were mostly heavily pretreated with 77% have three or more prior regimens. A total of 12 patients (36%) suffered grade 3-4 drug associated adverse event (AE); no grade 5 AE were reported. Of the 33 evaluable patients, best response was PR in 3 (9%), SD in 14 (43%), and PD in 16 (48%) with responses confirmed by a second reviewer. Median time to progression of disease was 53 days (95% CI 42-113) and Median time to death was 129 days (95% CI 86-199 days). Progression free survival at 4 months (PFS-4) on Evo-Bev was 31%, which was a statistically significant improvement over the historical rate of 3%. The median overall survival of patients receiving Evo-Bevacizumab was 4.6 months (95% CI 2.9-6.6). The progression free survival of patients on Evo-Bevacizumab met the primary endpoint of progression free survival at 4 months of 31%, although the clinical significance of this may be limited. Given the patient population and Phase II design, these clinical outcomes will need further validation.
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http://dx.doi.org/10.1038/s41598-021-81841-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7841164PMC
January 2021

Activation of estrogen receptor beta signaling reduces stemness of glioma stem cells.

Stem Cells 2021 05 1;39(5):536-550. Epub 2021 Feb 1.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, Texas, USA.

Glioblastoma (GBM) is the most common and deadliest tumor of the central nervous system. GBM has poor prognosis and glioma stem cells (GSCs) are implicated in tumor initiation and therapy resistance. Estrogen receptor β (ERβ) is expressed in GBM and exhibit tumor suppressive function. However, the role of ERβ in GSCs and the therapeutic potential of ERβ agonists on GSCs remain largely unknown. Here, we examined whether ERβ modulates GSCs stemness and tested the utility of two ERβ selective agonists (LY500307 and Liquiritigenin) to reduce the stemness of GSCs. The efficacy of ERβ agonists was examined on GSCs isolated from established and patient derived GBMs. Our results suggested that knockout of ERβ increased the proportion of CD133+ and SSEA+ positive GSCs and overexpression of ERβ reduced the proportion of GSCs in GBM cells. Overexpression of ERβ or treatment with ERβ agonists significantly inhibited the GSCs cell viability, neurosphere formation, self-renewal ability, induced the apoptosis and reduced expression of stemness markers in GSCs. RNA sequencing analysis revealed that ERβ agonist modulate pathways related to stemness, differentiation and apoptosis. Mechanistic studies showed that ERβ overexpression or agonist treatment reduced glutamate receptor signaling pathway and induced apoptotic pathways. In orthotopic models, ERβ overexpression or ERβ agonists treatment significantly reduced the GSCs mediated tumor growth and improved the mice overall survival. Immunohistochemical studies demonstrated that ERβ overexpression decreased SOX2 and GRM3 expression and increased expression of GFAP in tumors. These results suggest that ERβ activation could be a promising therapeutic strategy to eradicate GSCs.
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http://dx.doi.org/10.1002/stem.3337DOI Listing
May 2021

KDM1A inhibition is effective in reducing stemness and treating triple negative breast cancer.

Breast Cancer Res Treat 2021 Jan 14;185(2):343-357. Epub 2020 Oct 14.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.

Purpose: Cancer stem cells (CSCs) are highly tumorigenic, spared by chemotherapy, sustain tumor growth, and are implicated in tumor recurrence after conventional therapies in triple negative breast cancer (TNBC). Lysine-specific histone demethylase 1A (KDM1A) is highly expressed in several human malignancies and CSCs including TNBC. However, the precise mechanistic role of KDM1A in CSC functions and therapeutic utility of KDM1A inhibitor for treating TNBC is poorly understood.

Methods: The effect of KDM1A inhibition on cell viability, apoptosis, and invasion were examined by Cell Titer Glo, Caspase 3/7 Glo, and matrigel invasion assays, respectively. Stemness and self-renewal of CSCs were examined using mammosphere formation and extreme limiting dilution assays. Mechanistic studies were conducted using RNA-sequencing, RT-qPCR, Western blotting and reporter gene assays. Mouse xenograft and patient derived xenograft models were used for preclinical evaluation of KDM1A inhibitor.

Results: TCGA data sets indicated that KDM1A is highly expressed in TNBC. CSCs express high levels of KDM1A and inhibition of KDM1A reduced the CSCs enrichment in TNBC cells. KDM1A inhibition reduced cell viability, mammosphere formation, self-renewal and promoted apoptosis of CSCs. Mechanistic studies suggested that IL6-JAK-STAT3 and EMT pathways were downregulated in KDM1A knockdown and KDM1A inhibitor treated cells. Importantly, doxycycline inducible knockout of KDM1A reduced tumor progression in orthotopic xenograft models and KDM1A inhibitor NCD38 treatment significantly reduced tumor growth in patient derived xenograft (PDX) models.

Conclusions: Our results establish that KDM1A inhibition mitigates CSCs functions via inhibition of STAT3 and EMT signaling, and KDM1A inhibitor NCD38 may represent a novel class of drug for treating TNBC.
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http://dx.doi.org/10.1007/s10549-020-05963-1DOI Listing
January 2021

PELP1 promotes glioblastoma progression by enhancing Wnt/β-catenin signaling.

Neurooncol Adv 2019 May-Dec;1(1):vdz042. Epub 2019 Nov 5.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, Texas.

Background: Glioblastoma (GBM) is a deadly neoplasm of the central nervous system. The molecular mechanisms and players that contribute to GBM development is incompletely understood.

Methods: The expression of PELP1 in different grades of glioma and normal brain tissues was analyzed using immunohistochemistry on a tumor tissue array. PELP1 expression in established and primary GBM cell lines was analyzed by Western blotting. The effect of PELP1 knockdown was studied using cell proliferation, colony formation, migration, and invasion assays. Mechanistic studies were conducted using RNA-seq, RT-qPCR, immunoprecipitation, reporter gene assays, and signaling analysis. Mouse orthotopic models were used for preclinical evaluation of PELP1 knock down.

Results: Nuclear receptor coregulator PELP1 is highly expressed in gliomas compared to normal brain tissues, with the highest expression in GBM. PELP1 expression was elevated in established and patient-derived GBM cell lines compared to normal astrocytes. Knockdown of PELP1 resulted in a significant decrease in cell viability, survival, migration, and invasion. Global RNA-sequencing studies demonstrated that PELP1 knockdown significantly reduced the expression of genes involved in the Wnt/β-catenin pathway. Mechanistic studies demonstrated that PELP1 interacts with and functions as a coactivator of β-catenin. Knockdown of PELP1 resulted in a significant increase in survival of mice implanted with U87 and GBM PDX models.

Conclusions: PELP1 expression is upregulated in GBM and PELP1 signaling via β-catenin axis contributes to GBM progression. Thus, PELP1 could be a potential target for the development of therapeutic intervention in GBM.
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http://dx.doi.org/10.1093/noajnl/vdz042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7147719PMC
November 2019

Phase 1 study of MRX34, a liposomal miR-34a mimic, in patients with advanced solid tumours.

Br J Cancer 2020 05 2;122(11):1630-1637. Epub 2020 Apr 2.

The University of Texas Southwestern Medical Center, Dallas, TX, USA.

Background: In this first-in-human, Phase 1 study of a microRNA-based cancer therapy, the recommended Phase 2 dose (RP2D) of MRX34, a liposomal mimic of microRNA-34a (miR-34a), was determined and evaluated in patients with advanced solid tumours.

Methods: Adults with various solid tumours refractory to standard treatments were enrolled in 3 + 3 dose-escalation cohorts and, following RP2D determination, expansion cohorts. MRX34, with oral dexamethasone premedication, was given intravenously daily for 5 days in 3-week cycles.

Results: Common all-cause adverse events observed in 85 patients enrolled included fever (% all grade/G3: 72/4), chills (53/14), fatigue (51/9), back/neck pain (36/5), nausea (36/1) and dyspnoea (25/4). The RP2D was 70 mg/m for hepatocellular carcinoma (HCC) and 93 mg/m for non-HCC cancers. Pharmacodynamic results showed delivery of miR-34a to tumours, and dose-dependent modulation of target gene expression in white blood cells. Three patients had PRs and 16 had SD lasting ≥4 cycles (median, 19 weeks, range, 11-55).

Conclusion: MRX34 treatment with dexamethasone premedication demonstrated a manageable toxicity profile in most patients and some clinical activity. Although the trial was closed early due to serious immune-mediated AEs that resulted in four patient deaths, dose-dependent modulation of relevant target genes provides proof-of-concept for miRNA-based cancer therapy.

Clinical Trial Registration: NCT01829971.
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http://dx.doi.org/10.1038/s41416-020-0802-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7251107PMC
May 2020

ANG1005, a Brain-Penetrating Peptide-Drug Conjugate, Shows Activity in Patients with Breast Cancer with Leptomeningeal Carcinomatosis and Recurrent Brain Metastases.

Clin Cancer Res 2020 06 22;26(12):2789-2799. Epub 2020 Jan 22.

Department of Breast Medical Oncology, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center; Houston, Texas.

Purpose: ANG1005, a novel taxane derivative, consists of three paclitaxel molecules covalently linked to Angiopep-2, designed to cross the blood-brain and blood-cerebrospinal barriers and to penetrate malignant cells via LRP1 transport system. Preclinical and clinical evidence of efficacy with ANG1005 has been previously shown.

Patients And Methods: A multicenter, open-label phase II study in adult patients with measurable recurrent brain metastases from breast cancer (BCBM), with or without leptomeningeal carcinomatosis was conducted ( = 72 BCBM; = 28 leptomeningeal carcinomatosis subset). ANG1005 was administered intravenously at 600 mg/m every 3 weeks. Tumor assessment was based on central nervous system (CNS) RECIST 1.1 for intracranial, and RECIST 1.1 for extracranial response. The primary endpoint was determination of intracranial objective response rate (iORR).

Results: Median age was 47.5 years. Safety profile was similar to that of paclitaxel with myelosuppression as the predominating toxicity. Average number of prior CNS-directed therapies was 2.8 and 94% of the patients had prior taxane treatment. Patient benefit (stable disease or better) was seen in 77% (intracranial) and 86% (extracranial) of the evaluable patients, with iORR of 15% (investigator) or 8% (independent radiology facility [IRF] review). In the leptomeningeal carcinomatosis subset, 79% of the patients had intracranial disease control and estimated median overall survival of 8.0 months (95% CI, 5.4-9.4).

Conclusions: Even though the study preset rule for iORR per IRF was not met in this heavily pretreated population, a notable CNS and systemic treatment effect was seen in all patients including symptom improvement and prolonged overall survival compared to historical control for the subset of patients with leptomeningeal carcinomatosis ( = 28).
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http://dx.doi.org/10.1158/1078-0432.CCR-19-3258DOI Listing
June 2020

PELP1 signaling contributes to medulloblastoma progression by regulating the NF-κB pathway.

Mol Carcinog 2020 03 24;59(3):281-292. Epub 2019 Dec 24.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, Texas.

Medulloblastoma (MB) is the most common and deadliest brain tumor in children. Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) is a scaffolding protein and its oncogenic signaling is implicated in the progression of several cancers. However, the role of PELP1 in the progression of MB remains unknown. The objective of this study is to examine the role of PELP1 in the progression of MB. Immunohistochemical analysis of MB tissue microarrays revealed that PELP1 is overexpressed in the MB specimens compared to normal brain. Knockdown of PELP1 reduced cell proliferation, cell survival, and cell invasion of MB cell lines. The RNA-sequencing analysis revealed that PELP1 knockdown significantly downregulated the pathways related to inflammation and extracellular matrix. Gene set enrichment analysis confirmed that the PELP1-regulated genes were negatively correlated with nuclear factor-κB (NF-κB), extracellular matrix, and angiogenesis gene sets. Interestingly, PELP1 knockdown reduced the expression of NF-κB target genes, NF-κB reporter activity, and inhibited the nuclear translocation of p65. Importantly, the knockdown of PELP1 significantly reduced in vivo MB progression in orthotopic models and improved the overall mice survival. Collectively, these results suggest that PELP1 could be a novel target for therapeutic intervention in MB.
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http://dx.doi.org/10.1002/mc.23152DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7021561PMC
March 2020

Everolimus Inhibits the Progression of Ductal Carcinoma to Invasive Breast Cancer Via Downregulation of MMP9 Expression.

Clin Cancer Res 2020 03 23;26(6):1486-1496. Epub 2019 Dec 23.

Department of Cell Systems and Anatomy, School of Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas.

Purpose: We evaluated the role of everolimus in the prevention of ductal carcinoma (DCIS) to invasive ductal carcinoma (IDC) progression.

Experimental Design: The effects of everolimus on breast cancer cell invasion, DCIS formation, and DCIS progression to IDC were investigated in a 3D cell culturing model, intraductal DCIS xenograft model, and spontaneous MMTV-Her2/neu mouse model. The effect of everolimus on matrix metalloproteinase 9 (MMP9) expression was determined with Western blotting and IHC in these models and in patients with DCIS before and after a window trial with rapamycin. Whether MMP9 mediates the inhibition of DCIS progression to IDC by everolimus was investigated with knockdown or overexpression of MMP9 in breast cancer cells.

Results: Everolimus significantly inhibited the invasion of human breast cancer cells . Daily intragastric treatment with everolimus for 7 days significantly reduced the number of invasive lesions from intraductal DCIS foci and inhibited DCIS progression to IDC in the MMTV-Her2/neu mouse mammary tumor model. Mechanistically, everolimus treatment decreased the expression of MMP9 in the and models, and in breast tissues from patients with DCIS treated with rapamycin for 1 week. Moreover, overexpression of MMP9 stimulated the invasion, whereas knockdown of MMP9 inhibited the invasion of breast cancer cell-formed spheroids and DCIS . Knockdown of MMP9 also nullified the invasion inhibition by everolimus and .

Conclusions: Targeting mTORC1 can inhibit DCIS progression to IDC via MMP9 and may be a potential strategy for DCIS or early-stage IDC therapy.
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http://dx.doi.org/10.1158/1078-0432.CCR-19-2478DOI Listing
March 2020

Safety and efficacy of VB-111, an anticancer gene therapy, in patients with recurrent glioblastoma: results of a phase I/II study.

Neuro Oncol 2020 05;22(5):694-704

Center for Neuro-Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts, USA.

Background: VB-111 is a non-replicating adenovirus carrying a Fas-chimera transgene, leading to targeted apoptosis of tumor vascular endothelium and induction of a tumor-specific immune response. This phase I/II study evaluated the safety, tolerability, and efficacy of VB-111 with and without bevacizumab in recurrent glioblastoma (rGBM).

Methods: Patients with rGBM (n = 72) received VB-111 in 4 treatment groups: subtherapeutic (VB-111 dose escalation), limited exposure (LE; VB-111 monotherapy until progression), primed combination (VB-111 monotherapy continued upon progression with combination of bevacizumab), and unprimed combination (upfront combination of VB-111 and bevacizumab). The primary endpoint was median overall survival (OS). Secondary endpoints were safety, overall response rate, and progression-free survival (PFS).

Results: VB-111 was well tolerated. The most common adverse event was transient mild-moderate fever. Median OS time was significantly longer in the primed combination group compared with both LE (414 vs 223 days; hazard ratio [HR], 0.48; P = 0.043) and unprimed combination (414 vs 141.5 days; HR, 0.24; P = 0.0056). Patients in the combination phase of the primed combination group had a median PFS time of 90 days compared with 60 in the LE group (HR, 0.36; P = 0.032), and 63 in the unprimed combination group (P = 0.72). Radiographic responders to VB-111 exhibited characteristic, expansive areas of necrosis in the areas of initial enhancing disease.

Conclusions: Patients with rGBM who were primed with VB-111 monotherapy that continued after progression with the addition of bevacizumab showed significant survival and PFS advantage, as well as specific imaging characteristics related to VB-111 mechanism of action. These results warrant further assessment in a randomized controlled study.
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http://dx.doi.org/10.1093/neuonc/noz231DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7229257PMC
May 2020

Stable Isotope Dilution LC-HRMS Assay To Determine Free SN-38, Total SN-38, and SN-38G in a Tumor Xenograft Model after Intravenous Administration of Antibody-Drug Conjugate (Sacituzumab Govitecan).

Anal Chem 2020 01 9;92(1):1260-1267. Epub 2019 Dec 9.

Antibody-drug conjugates (ADCs) have gained significant interest over the past few years due to their targeted delivery, higher efficacy, decreased toxicity and improved therapeutic index over conventional anticancer therapies. Sacituzumab govitecan (SG) is an ADC composed of a Trop-2-targeted antibody conjugated to the cytotoxic payload SN-38. SG is currently being evaluated in clinical trials of several solid cancers. In this nonclinical study, we have developed a highly sensitive and selective approach to measure free and total SN-38 and its glucuronidation metabolite (SN-38G) using stable isotope dilution (SID) ultrahigh-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). An efficient and fast hydrolysis procedure (2 h at 100 °C) was established to release SN-38, conjugated to the antibody by carbonate linkage. The assay involves the extraction of free SN-38, SN-38G by protein precipitation, and subsequent acid hydrolysis of the protein layer to release antibody-bound SN-38. The developed UHPLC-HRMS method resulted in good linearity ( ≥ 0.997), accuracy (RE ≤ ± 9.1%), precision (CVs ≤ 7.7%), and extraction recoveries (85.6-109.3%). The validated method was applied in the plasma and tumor of mice bearing human brain (U251) and breast (MDA-MB-468) tumor xenografts treated with a single dose (0.5 mg) of SG for 6 h. Results revealed the presence of trace level of SN-38G and free SN-38 in plasma, which suggests an improved therapeutic index of SG. The established method makes a significant contribution to the assessment of SG in different cancers.
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http://dx.doi.org/10.1021/acs.analchem.9b04419DOI Listing
January 2020

Laser brain cancer surgery in a xenograft model guided by optical coherence tomography.

Theranostics 2019 26;9(12):3555-3564. Epub 2019 May 26.

University of Texas at Austin.

Higher precision surgical devices are needed for tumor resections near critical brain structures. The goal of this study is to demonstrate feasibility of a system capable of precise and bloodless tumor ablation. An image-guided laser surgical system is presented for excision of brain tumors in a murine xenograft model. The system combines optical coherence tomography (OCT) guidance with surgical lasers for high-precision tumor ablation (Er:YAG) and microcirculation coagulation (Thulium (Tm) fiber laser). A fluorescent human glioblastoma cell line was injected into mice and allowed to grow four weeks. Craniotomies were performed and tumors were imaged with confocal fluorescence microscopy. The mice were subsequently OCT imaged prior, during and after laser coagulation and/or ablation. The prior OCT images were used to compute three-dimensional tumor margin and angiography images, which guided the coagulation and ablation steps. Histology of the treated regions was then compared to post-treatment OCT images. Tumor sizing based on OCT margin detection matched histology to within experimental error. Although fluorescence microscopy imaging showed the tumors were collocated with OCT imaging, margin assessment using confocal microscopy failed to see the extent of the tumor beyond ~ 250 µm in depth, as verified by OCT and histology. The two-laser approach to surgery utilizing Tm wavelength for coagulation and Er:YAG for ablation yielded bloodless resection of tumor regions with minimal residual damage as seen in histology. Precise and bloodless tumor resection under OCT image guidance is demonstrated in the murine xenograft brain cancer model. Tumor margins and vasculature are accurately made visible without need for exogenous contrast agents.
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http://dx.doi.org/10.7150/thno.31811DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6587169PMC
June 2020

EC359: A First-in-Class Small-Molecule Inhibitor for Targeting Oncogenic LIFR Signaling in Triple-Negative Breast Cancer.

Mol Cancer Ther 2019 Aug 29;18(8):1341-1354. Epub 2019 May 29.

Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, Texas.

Leukemia inhibitory factor receptor (LIFR) and its ligand LIF play a critical role in cancer progression, metastasis, stem cell maintenance, and therapy resistance. Here, we describe a rationally designed first-in-class inhibitor of LIFR, EC359, which directly interacts with LIFR to effectively block LIF/LIFR interactions. EC359 treatment exhibits antiproliferative effects, reduces invasiveness and stemness, and promotes apoptosis in triple-negative breast cancer (TNBC) cell lines. The activity of EC359 is dependent on LIF and LIFR expression, and treatment with EC359 attenuated the activation of LIF/LIFR-driven pathways, including STAT3, mTOR, and AKT. Concomitantly, EC359 was also effective in blocking signaling by other LIFR ligands (CTF1, CNTF, and OSM) that interact at LIF/LIFR interface. EC359 significantly reduced tumor progression in TNBC xenografts and patient-derived xenografts (PDX), and reduced proliferation in patient-derived primary TNBC explants. EC359 exhibits distinct pharmacologic advantages, including oral bioavailability, and stability. Collectively, these data support EC359 as a novel targeted therapeutic that inhibits LIFR oncogenic signaling..
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http://dx.doi.org/10.1158/1535-7163.MCT-18-1258DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6677593PMC
August 2019

The current state of molecular testing in the treatment of patients with solid tumors, 2019.

CA Cancer J Clin 2019 07 22;69(4):305-343. Epub 2019 May 22.

Professor of Medicine and Oncology, Director, Ruesch Center for the Cure of Gastrointestinal Cancers, Lombardi Comprehensive Cancer Institute, MedStar Georgetown Cancer Institute, Washington, DC.

The world of molecular profiling has undergone revolutionary changes over the last few years as knowledge, technology, and even standard clinical practice have evolved. Broad molecular profiling is now nearly essential for all patients with metastatic solid tumors. New agents have been approved based on molecular testing instead of tumor site of origin. Molecular profiling methodologies have likewise changed such that tests that were performed on patients a few years ago are no longer complete and possibly inaccurate today. As with all rapid change, medical providers can quickly fall behind or struggle to find up-to-date sources to ensure he or she provides optimum care. In this review, the authors provide the current state of the art for molecular profiling/precision medicine, practice standards, and a view into the future ahead.
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http://dx.doi.org/10.3322/caac.21560DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6767457PMC
July 2019

Correction to: First results on survival from a large Phase 3 clinical trial of an autologous dendritic cell vaccine in newly diagnosed glioblastoma.

J Transl Med 2018 06 29;16(1):179. Epub 2018 Jun 29.

University of North Carolina, Chapel Hill, NC, USA.

Following publication of the original article [1], the authors reported an error in the spelling of one of the author names. In this Correction the incorrect and correct author names are indicated and the author name has been updated in the original publication. The authors also reported an error in the Methods section of the original article. In this Correction the incorrect and correct versions of the affected sentence are indicated. The original article has not been updated with regards to the error in the Methods section.
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http://dx.doi.org/10.1186/s12967-018-1552-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6026340PMC
June 2018

First results on survival from a large Phase 3 clinical trial of an autologous dendritic cell vaccine in newly diagnosed glioblastoma.

J Transl Med 2018 05 29;16(1):142. Epub 2018 May 29.

University of North Carolina, Chapel Hill, NC, USA.

Background: Standard therapy for glioblastoma includes surgery, radiotherapy, and temozolomide. This Phase 3 trial evaluates the addition of an autologous tumor lysate-pulsed dendritic cell vaccine (DCVax-L) to standard therapy for newly diagnosed glioblastoma.

Methods: After surgery and chemoradiotherapy, patients were randomized (2:1) to receive temozolomide plus DCVax-L (n = 232) or temozolomide and placebo (n = 99). Following recurrence, all patients were allowed to receive DCVax-L, without unblinding. The primary endpoint was progression free survival (PFS); the secondary endpoint was overall survival (OS).

Results: For the intent-to-treat (ITT) population (n = 331), median OS (mOS) was 23.1 months from surgery. Because of the cross-over trial design, nearly 90% of the ITT population received DCVax-L. For patients with methylated MGMT (n = 131), mOS was 34.7 months from surgery, with a 3-year survival of 46.4%. As of this analysis, 223 patients are ≥ 30 months past their surgery date; 67 of these (30.0%) have lived ≥ 30 months and have a Kaplan-Meier (KM)-derived mOS of 46.5 months. 182 patients are ≥ 36 months past surgery; 44 of these (24.2%) have lived ≥ 36 months and have a KM-derived mOS of 88.2 months. A population of extended survivors (n = 100) with mOS of 40.5 months, not explained by known prognostic factors, will be analyzed further. Only 2.1% of ITT patients (n = 7) had a grade 3 or 4 adverse event that was deemed at least possibly related to the vaccine. Overall adverse events with DCVax were comparable to standard therapy alone.

Conclusions: Addition of DCVax-L to standard therapy is feasible and safe in glioblastoma patients, and may extend survival. Trial registration Funded by Northwest Biotherapeutics; Clinicaltrials.gov number: NCT00045968; https://clinicaltrials.gov/ct2/show/NCT00045968?term=NCT00045968&rank=1 ; initially registered 19 September 2002.
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http://dx.doi.org/10.1186/s12967-018-1507-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5975654PMC
May 2018

Metabolomic signature of brain cancer.

Mol Carcinog 2017 Nov 17;56(11):2355-2371. Epub 2017 Jul 17.

Department of Nutritional Sciences, The University of Texas at Austin, Austin, Texas.

Despite advances in surgery and adjuvant therapy, brain tumors represent one of the leading causes of cancer-related mortality and morbidity in both adults and children. Gliomas constitute about 60% of all cerebral tumors, showing varying degrees of malignancy. They are difficult to treat due to dismal prognosis and limited therapeutics. Metabolomics is the untargeted and targeted analyses of endogenous and exogenous small molecules, which charact erizes the phenotype of an individual. This emerging "omics" science provides functional readouts of cellular activity that contribute greatly to the understanding of cancer biology including brain tumor biology. Metabolites are highly informative as a direct signature of biochemical activity; therefore, metabolite profiling has become a promising approach for clinical diagnostics and prognostics. The metabolic alterations are well-recognized as one of the key hallmarks in monitoring disease progression, therapy, and revealing new molecular targets for effective therapeutic intervention. Taking advantage of the latest high-throughput analytical technologies, that is, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), metabolomics is now a promising field for precision medicine and drug discovery. In the present report, we review the application of metabolomics and in vivo metabolic profiling in the context of adult gliomas and paediatric brain tumors. Analytical platforms such as high-resolution (HR) NMR, in vivo magnetic resonance spectroscopic imaging and high- and low-resolution MS are discussed. Moreover, the relevance of metabolic studies in the development of new therapeutic strategies for treatment of gliomas are reviewed.
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http://dx.doi.org/10.1002/mc.22694DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5708886PMC
November 2017

Phase I study of MRX34, a liposomal miR-34a mimic, administered twice weekly in patients with advanced solid tumors.

Invest New Drugs 2017 04 5;35(2):180-188. Epub 2016 Dec 5.

UT MD Anderson Cancer Center, Houston, TX, USA.

Purpose Naturally occurring tumor suppressor microRNA-34a (miR-34a) downregulates the expression of >30 oncogenes across multiple oncogenic pathways, as well as genes involved in tumor immune evasion, but is lost or under-expressed in many malignancies. This first-in-human, phase I study assessed the maximum tolerated dose (MTD), safety, pharmacokinetics, and clinical activity of MRX34, a liposomal miR-34a mimic, in patients with advanced solid tumors. Patients and Methods Adult patients with solid tumors refractory to standard treatment were enrolled in a standard 3 + 3 dose escalation trial. MRX34 was given intravenously twice weekly (BIW) for three weeks in 4-week cycles. Results Forty-seven patients with various solid tumors, including hepatocellular carcinoma (HCC; n = 14), were enrolled. Median age was 60 years, median prior therapies was 4 (range, 1-12), and most were Caucasian (68%) and male (57%). Most common adverse events (AEs) included fever (all grade %/G3%: 64/2), fatigue (57/13), back pain (57/11), nausea (49/2), diarrhea (40/11), anorexia (36/4), and vomiting (34/4). Laboratory abnormalities included lymphopenia (G3%/G4%: 23/9), neutropenia (13/11), thrombocytopenia (17/0), increased AST (19/4), hyperglycemia (13/2), and hyponatremia (19/2). Dexamethasone premedication was required to manage infusion-related AEs. The MTD for non-HCC patients was 110 mg/m, with two patients experiencing dose-limiting toxicities of G3 hypoxia and enteritis at 124 mg/m. The half-life was >24 h, and C and AUC increased with increasing dose. One patient with HCC achieved a prolonged confirmed PR lasting 48 weeks, and four patients experienced SD lasting ≥4 cycles. Conclusion MRX34 treatment with dexamethasone premedication was associated with acceptable safety and showed evidence of antitumor activity in a subset of patients with refractory advanced solid tumors. The MTD for the BIW schedule was 110 mg/m for non-HCC and 93 mg/m2 for HCC patients. Additional dose schedules of MRX34 have been explored to improve tolerability.
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http://dx.doi.org/10.1007/s10637-016-0407-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5893501PMC
April 2017

5,10b-Ethanophenanthridine amaryllidaceae alkaloids inspire the discovery of novel bicyclic ring systems with activity against drug resistant cancer cells.

Eur J Med Chem 2016 Sep 6;120:313-28. Epub 2016 May 6.

Departments of Chemistry and Biology, New Mexico Institute of Mining and Technology, Socorro, NM 87801, USA. Electronic address:

Plants of the Amaryllidaceae family produce a large variety of alkaloids and non-basic secondary metabolites, many of which are investigated for their promising anticancer activities. Of these, crinine-type alkaloids based on the 5,10b-ethanophenanthridine ring system were recently shown to be effective at inhibiting proliferation of cancer cells resistant to various pro-apoptotic stimuli and representing tumors with dismal prognoses refractory to current chemotherapy, such as glioma, melanoma, non-small-cell lung, esophageal, head and neck cancers, among others. Using this discovery as a starting point and taking advantage of a concise biomimetic route to the crinine skeleton, a collection of crinine analogues were synthetically prepared and evaluated against cancer cells. The compounds exhibited single-digit micromolar activities and retained this activity in a variety of drug-resistant cancer cell cultures. This investigation resulted in the discovery of new bicyclic ring systems with significant potential in the development of effective clinical cancer drugs capable of overcoming cancer chemotherapy resistance.
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http://dx.doi.org/10.1016/j.ejmech.2016.05.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4943583PMC
September 2016

Obesity Suppresses Estrogen Receptor Beta Expression in Breast Cancer Cells via a HER2-Mediated Pathway.

PLoS One 2015 28;10(12):e0145452. Epub 2015 Dec 28.

Department of Nutritional Sciences, University of Texas at Austin, Austin, Texas, United States of America.

Obesity is associated with a worse breast cancer prognosis, while greater breast tumor estrogen receptor beta (ERβ) expression is correlated with improved therapy response and survival. The objective of this study was to determine the impact of obesity on breast cancer cell ERβ expression, which is currently unknown. We utilized an in vitro model of obesity in which breast cancer cells were exposed to patient serum pooled by body mass index category (obese (OB): ≥30 kg/m2; normal weight (N): 18.5-24.9 kg/m2). Four human mammary tumor cell lines representing the major breast cancer subtypes (SKBR3, MCF-7, ZR75, MDA-MB-231) and mammary tumor cells from MMTV-neu mice were used. ERβ expression, assessed by qPCR and western blotting, was suppressed in the two HER2-overexpressing cell lines (SKBR3, MMTV-neu) following OB versus N sera exposure, but did not vary in the other cell lines. Expression of Bcl-2 and cyclin D1, two genes negatively regulated by ERβ, was elevated in SKBR3 cells following exposure to OB versus N sera, but this difference was eliminated when the ERβ gene was silenced with siRNA. Herceptin, a HER2 antagonist, and siRNA to HER2 were used to evaluate the role of HER2 in sera-induced ERβ modulation. SKBR3 cell treatment with OB sera plus Herceptin increased ERβ expression three-fold. Similar results were obtained when HER2 expression was silenced with siRNA. OB sera also promoted greater SKBR3 cell viability and growth, but this variance was not present when ERβ was silenced or the cells were modified to overexpress ERβ. Based on this data, we conclude that obesity-associated systemic factors suppress ERβ expression in breast cancer cells via a HER2-mediated pathway, leading to greater cell viability and growth. Elucidation of the mechanism(s) mediating this effect could provide important insights into how ERβ expression is regulated as well as how obesity promotes a more aggressive disease.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0145452PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692402PMC
July 2016

Fungal metabolite ophiobolin A as a promising anti-glioma agent: In vivo evaluation, structure-activity relationship and unique pyrrolylation of primary amines.

Bioorg Med Chem Lett 2015 Oct 24;25(20):4544-8. Epub 2015 Aug 24.

Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA. Electronic address:

Glioblastoma, the most common form of malignant primary brain tumor, is characterized by resistance to apoptosis, which is largely responsible for the low effectiveness of the classical chemotherapeutic approaches based on apoptosis induction in cancer cells. Previously, a fungal secondary metabolite ophiobolin A was found to have significant activity against apoptosis-resistant glioblastoma cells through the induction of a non-apoptotic cell death, thus, offering an innovative strategy to combat this type of cancer. The current work describes the results of a preliminary evaluation of ophiobolin A in an in vivo glioblastoma model and its chemical derivatization to establish first synthetically generated structure-activity relationship. The synthetic work has also led to the discovery of a unique reaction of ophiobolin A with primary amines suggesting the possibility of pyrrolylation of lysine residues on its intracellular target protein(s).
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http://dx.doi.org/10.1016/j.bmcl.2015.08.066DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4592837PMC
October 2015

VB-111: a novel anti-vascular therapeutic for glioblastoma multiforme.

J Neurooncol 2015 Sep 25;124(3):365-72. Epub 2015 Jun 25.

Cancer Therapy and Research Center, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229-3900, USA.

Glioblastoma multiforme (GBM) is among the most highly vascularized of solid tumors, contributing to the infiltrative nature of the disease, and conferring poor outcome. Due to the critical dependency of GBM on growth of new endothelial vasculature, we evaluated the preclinical activity of a novel adenoviral gene therapy that targets the endothelium within newly formed blood vessels for apoptosis. VB-111, currently in phase II clinical trials, consists of a non-replicating Adenovirus 5 (El deleted) carrying a proapoptotic human Fas-chimera (transgene) under the control of a modified murine promoter (PPE-1-3×) which specifically targets endothelial cells within the tumor vasculature. Here we report that a single intravenous dose of 2.5 × 10(11) or 1 × 10(11) VPs was sufficient to extend survival in nude rats bearing U87MG-luc2 or nude mice bearing U251-luc, respectively. Bioluminescence imaging of nude rats showed that VB-111 effectively inhibited tumor growth within four weeks of treatment. This was confirmed in a select group of animals by MRI. In our mouse model we observed that 3 of 10 nude mice treated with VB-111 completely lost U251 luciferase signal and were considered long term survivors. To assess the antiangiogenic effects of VB-111, we evaluated the tumor-associated microvaculature by CD31, a common marker of neovascularization, and found a significant decrease in the microvessel density by IHC. We further assessed the neovasculature by confocal microscopy and found that VB-111 inhibits vascular density in two separate mouse models bearing U251-RFP xenografts. Collectively, this study supports the clinical development of VB-111 as a treatment for GBM.
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http://dx.doi.org/10.1007/s11060-015-1853-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4584173PMC
September 2015

Hypoxia in astrocytic tumors and implications for therapy.

Neurobiol Dis 2016 Jan 19;85:227-233. Epub 2015 Jun 19.

Cancer Therapy and Research Center, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA. Electronic address:

Glioblastoma (GBM, Grade IV astrocytoma) is the most common and most aggressive of the primary malignant brain tumors in adults. Hypoxia is a distinct feature in GBM and plays a significant role in tumor progression, resistance to treatment and poor outcomes. This review considers the effects of hypoxia on astrocytic tumors and the mechanisms that contribute to tumor progression and therapeutic resistance, with a focus on the vascular changes, chemotaxic signaling pathways and metabolic alterations involved.
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http://dx.doi.org/10.1016/j.nbd.2015.06.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4684800PMC
January 2016

Activity of 2-aryl-2-(3-indolyl)acetohydroxamates against drug-resistant cancer cells.

J Med Chem 2015 Mar 20;58(5):2206-20. Epub 2015 Feb 20.

Department of Chemistry, North Caucasus Federal University , 1a Pushkin St., Stavropol 355009, Russian Federation.

Many types of tumor, including glioma, melanoma, non-small cell lung, esophageal, and head and neck cancer, among others, are intrinsically resistant to apoptosis induction and poorly responsive to current therapies with proapoptotic agents. In addition, tumors often develop multidrug resistance based on the cellular efflux of chemotherapeutic agents. Thus, novel anticancer agents capable of overcoming these intrinsic or developed tumor resistance mechanisms are urgently needed. We describe a series of 2-aryl-2-(3-indolyl)acetohydroxamic acids that are active against apoptosis- and multidrug-resistant cancer cells as well as glioblastoma neurosphere stemlike cell cultures derived from patients. Thus, the described compounds serve as a novel chemical scaffold for the development of potentially highly effective clinical cancer drugs.
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http://dx.doi.org/10.1021/jm501518yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4944210PMC
March 2015

Obesity-associated systemic interleukin-6 promotes pre-adipocyte aromatase expression via increased breast cancer cell prostaglandin E2 production.

Breast Cancer Res Treat 2015 Jan 5;149(1):49-57. Epub 2014 Dec 5.

Department of Nutrition, University of North Carolina at Chapel Hill, 135 Dauer Drive, McGavran-Greenberg Hall, Chapel Hill, NC, 27599, USA,

Obesity is associated with a worse breast cancer prognosis, particularly in estrogen receptor alpha (ERα) positive, postmenopausal patients. We hypothesized that this is mediated in part by an elevation in breast cancer cell cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production that results in greater local pre-adipocyte aromatase expression. We utilized an in vitro model of the obese patient's tumor microenvironment in which cultured MCF-7 breast cancer cells and pre-adipocytes were exposed to pooled serum from obese (OB; BMI ≥ 30.0 kg/m(2)) or normal weight (N; BMI 18.5-24.9 kg/m(2)) postmenopausal women. Exposure to OB versus N sera significantly increased MCF-7 cell COX-2 expression and PGE2 production. Pre-adipocyte aromatase expression was 89 % greater following culture in conditioned media (CM) from MCF-7 cells exposed to OB versus N sera (OB-CM and N-CM, respectively), a difference nullified by MCF-7 cell treatment with the COX-2 inhibitor celecoxib. Previous analysis of the sera revealed significantly higher interleukin-6 (IL-6) concentrations in the OB versus N samples. Depletion of IL-6 from the sera neutralized the difference in pre-adipocyte aromatase expression stimulated by OB-CM versus N-CM. Finally, CM from pre-adipocyte/MCF-7 cell co-cultures exposed to OB sera stimulated greater MCF-7 and T47D breast cancer cell ERα activity and proliferation in comparison to N sera. This study indicates that obesity-associated systemic IL-6 indirectly enhances pre-adipocyte aromatase expression via increased breast cancer cell PGE2 production. Investigation regarding the efficacy of a COX-2 inhibitor/aromatase inhibitor combination therapy in the obese postmenopausal patient population is warranted.
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http://dx.doi.org/10.1007/s10549-014-3223-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4409140PMC
January 2015

NSAID use reduces breast cancer recurrence in overweight and obese women: role of prostaglandin-aromatase interactions.

Cancer Res 2014 Aug;74(16):4446-57

Department of Nutritional Sciences, University of Texas at Austin, Austin, Texas.

Obesity is associated with a worse breast cancer prognosis and elevated levels of inflammation, including greater cyclooxygenase-2 (COX-2) expression and activity in adipose-infiltrating macrophages. The product of this enzyme, the proinflammatory eicosanoid prostaglandin E2 (PGE2), stimulates adipose tissue aromatase expression and subsequent estrogen production, which could promote breast cancer progression. This study demonstrates that daily use of a nonsteroidal anti-inflammatory drug (NSAID), which inhibits COX-2 activity, is associated with reduced estrogen receptor α (ERα)-positive breast cancer recurrence in obese and overweight women. Retrospective review of data from ERα-positive patients with an average body mass index of >30 revealed that NSAID users had a 52% lower recurrence rate and a 28-month delay in time to recurrence. To examine the mechanisms that may be mediating this effect, we conducted in vitro studies that utilized sera from obese and normal-weight patients with breast cancer. Exposure to sera from obese patients stimulated greater macrophage COX-2 expression and PGE2 production. This was correlated with enhanced preadipocyte aromatase expression following incubation in conditioned media (CM) collected from the obese-patient, sera-exposed macrophages, an effect neutralized by COX-2 inhibition with celecoxib. In addition, CM from macrophage/preadipocyte cocultures exposed to sera from obese patients stimulated greater breast cancer cell ERα activity, proliferation, and migration compared with sera from normal-weight patients, and these differences were eliminated or reduced by the addition of an aromatase inhibitor during CM generation. Prospective studies designed to examine the clinical benefit of NSAID use in obese patients with breast cancer are warranted.
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http://dx.doi.org/10.1158/0008-5472.CAN-13-3603DOI Listing
August 2014

Protein imprinting in polyacrylamide-based gels.

Biomaterials 2014 Oct 14;35(30):8659-68. Epub 2014 Jul 14.

Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218, USA; Institute for Nanobiotechnology, Johns Hopkins University, Baltimore, MD 21218, USA. Electronic address:

Protein imprinting in hydrogels is a method to produce materials capable of selective recognition and capture of a target protein. Here we report on the imprinting of fluorescently-labeled maltose binding protein (MBP) in acrylamide (AAm)/N-isopropylacrylamide (NIPAm) hydrogels. The targeting efficiency and selectivity of protein recognition is usually characterized by the imprinting factor, which in the simplest case is the ratio of protein uptake in an imprinted film divided by the uptake by the corresponding non-imprinted film. Our objective in this work is to study the dynamics of protein binding and elution in imprinted and non-imprinted films to elucidate the processes that control protein recognition. Protein elution from imprinted and non-imprinted films suggests that imprinting results in sites with a distribution of binding energies, and that only a relatively small fraction of these sites exhibit strong binding.
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http://dx.doi.org/10.1016/j.biomaterials.2014.05.079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4352324PMC
October 2014
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