Biomarker For Therapeutic Efficacy Research Articles

Multidrug resistance transporters P-gp and BCRP limit the efficacy of ATR inhibitor ceralasertib in cancer cells.

The therapeutic effect of chemotherapy and targeted therapy are known to be limited by drug resistance. Substantial evidence has shown that ATP-binding cassette (ABC) transporters P-gp and BCRP are significant contributors to multidrug resistance (MDR) in cancer cells. In this study, we demonstrated that a clinical-staged ATR inhibitor ceralasertib is susceptible to P-gp and BCRP-mediated MDR. The drug resistant cancer cells were less sensitive to ceralasertib compared to the parental cells. Moreover, ceralasertib resistance can be reversed by inhibiting the drug efflux activity of P-gp and BCRP. Interestingly, ceralasertib was able to downregulate the level of P-gp but not BCRP, suggesting a potential regulation between ATR signaling and P-gp expression. Furthermore, computational docking analysis predicted high affinities between ceralasertib and the drug-binding sites of P-gp and BCRP. In summary, overexpression of P-gp and BCRP are sufficient to confer cancer cells resistance to ceralasertib, underscoring their role as biomarkers for therapeutic efficacy.

Prognostic Nutritional Index after Introduction of Atezolizumab with Bevacizumab Predicts Prognosis in Advanced Hepatocellular Carcinoma: A Multicenter Study

Plain Language SummaryAtezolizumab plus bevacizumab (Atez/Bev) is the preferred treatment for advanced hepatocellular carcinoma (HCC). However, biomarkers of therapeutic efficacy have remained unclear. We took a retrospective approach to explore the role of prognostic nutritional index (PNI) for predicting the outcomes of Atez/Bev treatment. 125 HCC patients were enlisted; these patients received Atez/Bev treatment and underwent dynamic computerized tomography/magnetic resonance imaging to determine the treatment response on at least one occasion between October 2020 and January 2023, and their PNI before treatment and at the beginning of the second cycle (PNI-2c) was evaluated. During the initial evaluation, 2 (2%), 28 (22%), 70 (56%), and 25 (20%) patients exhibited a complete response, partial response, stable disease, and progressive disease (PD), respectively. Patients with non-PD tended to have higher PNI at baseline and PNI-2c than those with PD (p = 0.245 and 0.122, respectively), with optimal baseline PNI and PNI-2c cut-off values of 42.6 and 40.4, respectively. PNI at baseline could not be used to predict overall survival (OS) or progression-free survival (PFS). However, PNI-2c predicted OS and PFS (PNI-2c ≥ 40.4 vs. < 40.4: 25.3 vs. 16.2 months, p = 0.008 for OS; 12.7 vs. 8.4 months, p = 0.036 for PFS). A multivariate analysis showed a significant association between PNI-2c and OS. Therefore, PNI-2c is a predictor of prognosis in HCC patients treated with Atez/Bev therapy.

Interplay between inflammatory bowel disease therapeutics and the gut microbiome reveals opportunities for novel treatment approaches.

Inflammatory bowel disease (IBD) is a complex heterogeneous disorder defined by recurring chronic inflammation of the gastrointestinal tract, attributed to a combination of factors including genetic susceptibility, altered immune response, a shift in microbial composition/microbial insults (infection/exposure), and environmental influences. Therapeutics generally used to treat IBD mainly focus on the immune response and include non-specific anti-inflammatory and immunosuppressive therapeutics and targeted therapeutics aimed at specific components of the immune system. Other therapies include exclusive enteral nutrition and emerging stem cell therapies. However, in recent years, scientists have begun to examine the interplay between these therapeutics and the gut microbiome, and we present this information here. Many of these therapeutics are associated with alterations to gut microbiome composition and functionality, often driving it toward a "healthier profile" and preclinical studies have revealed that such alterations can play an important role in therapeutic efficacy. The gut microbiome can also improve or hinder IBD therapeutic efficacy or generate undesirable metabolites. For certain IBD therapeutics, the microbiome composition, particularly before treatment, may serve as a biomarker of therapeutic efficacy. Utilising this information and manipulating the interactions between the gut microbiome and IBD therapeutics may enhance treatment outcomes in the future and bring about new opportunities for personalised, precision medicine.

Effect of psychotherapy on peripheral BDNF concentration levels in patients with bipolar disorder. A systematic review

Introduction Psychotherapy is a treatment of proven efficacy in bipolar disorder (BD), but little is known about the molecular and cellular mechanisms that it produces in the brain. Brain-derived neurotrophic factor (BDNF) is thought to be important in neuroplasticity and could be increased by psychopharmaceuticals and psychotherapy in BD patients, but evidence in the literature is limited.ObjectivesTo analyze the scientific studies that relate psychotherapies with the increase in BNDF levels in patients with BD.MethodsSystematic review with PRISMA recommendations in PUBMED and Web of Science in July 2022. The search was performed using the combination of keywords “bipolar disorder” AND (“BDNF” OR “Brain Derived Neurotrophic Factor”) AND “psychotherapy”.ResultsWith the initial search, 839 studies were obtained, finally 8 articles were analyzed. The available literature supports the role of psychotherapy in increasing BNDF in patients with BD.ConclusionsBDNF could be a biomarker of therapeutic efficacy in BD. Psychotherapy increases BDNF levels. No differences were found between the different types of psychotherapies. More studies are needed to determine the mechanisms by which psychotherapies produce molecular changes in the brain.Disclosure of InterestNone Declared

851P Frequency and clinical significance of homologous recombination deficiency gene mutations in non-cutaneous melanoma

Homologous recombination deficiency (HRD) refers to the state of tumor cells which received defects in DNA-damage repair mechanisms. The HRD phenotype encodes important proteins for DNA homologous recombination repair (HRR) which can serve as a biomarker of therapeutic efficacy. Here, we explored the frequency and clinical significance of HRD gene mutations in non-cutaneous melanoma to provide experience for clinical options.

Abstract 2522: Exploring the prognostic and predictive value of circulating tumor DNA in patients with advanced colorectal cancer and chemotherapy

Abstract Background: Chemotherapy improves the survival of advanced colorectal cancer (CRC) patients but recurrences do happen frequently. Early indicators of reccurence/relapse post-chemotherapy are essential for optimal clinical decision. Circulating tumor DNA (ctDNA) are cancer-specific DNA fragments in plasma. They have been considered as predictive biomarkers of early stage CRC. However, the predictive value of ctDNA in advanced CRC is still undetermined. Here, we evaluate the applicability of early changes in ctDNA as a marker that might predict clinical course in advanced CRC patients after chemotherapy. Methods: 122 patients with CRC were enrolled and their ctDNA fingerprints, designed based on individual patient's top somatic mutated genes, were determined and monitored over time (~ 3-6 months interval). The patients were classified into high- and low-ctDNA groups divided by the median concentration of ctDNA. We subsequently analyzed the correlation between overall survival (OS) and ctDNA levels in patients with or without chemotherapy. The dynamics of ctDNA were used to assess the prognosis and OS. Results: In the 122 patients, higher ctDNA levels (above median) were associated with shorter OS (HR, 2.89; CI 95% 1.45-5.79, P=0.0027). The conclusion upheld in a subset of 48 who had advanced CRC (stage IV) and received chemotherapy (HR, 1.601, CI 95% 0.61-4.17, p=0.037). Moreover, changes of ctDNA were detected early during the chemotherapy treatment course. In the same 48 patients with advanced CRC and chemotherapy, those who had undetectable and decreased ctDNA had longer OS overall, suggesting that ctDNA dynamics is predictive of clinic change in chemotherapy in advanced CRC. Finally, compared with clinical imaging diagnosis, we found that approximately 52.9% (18/34) patients belonged to a “consistent” group, in which patients with decreased/undetectable ctDNA had relieved clinical diagnosis and patients with increased ctDNA had elevated diagnosis. However, 14.7% (5/34) patients had inconsistent results between imaging diagnosis and ctDNA monitoring, and 32.4% (11/34) patients were uncertain due to unstable ctDNA levels. Conclusion: This study confirms the association between baseline levels of ctDNA and survival times of CRC patients. Additionally, it also suggests the use of early change of ctDNA as a potential biomarker of therapeutic efficacy in CRC chemotherapy. Oncologists may be able to use ctDNA fingerprints to guide treatment decisions and predict individual patient's prognosis. Citation Format: Xiu Liu, Xuan Zhang, Kai Ou, Chelong Lu, Dong Zheng, Jun Liu, Qiang Xu, Lin Yang. Exploring the prognostic and predictive value of circulating tumor DNA in patients with advanced colorectal cancer and chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2522.

Investigation of drugs affecting hypertension in bevacizumab-treated patients and examination of the impact on the therapeutic effect.

BackgroundIn patients treated with bevacizumab, hypertension may be a biomarker of therapeutic efficacy. However, it is not clear whether drugs that control blood pressure influence bevacizumab's efficacy. In this study, we investigated drugs that may affect hypertension in bevacizumab‐treated patients and examined the impact on the therapeutic effect.Patients and methodsWe analyzed 3,724,555 reports from the third quarter of 2010 to the second quarter of 2015. All data were obtained from the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) analysis. In this retrospective cohort study, we investigated a total of 58 patients diagnosed with colorectal cancer and treated for the first time with bevacizumab containing XELOX or mFOLFOX6 at The University of Tokushima Hospital between January 2010 and December 2015. The effect of the treatment was evaluated according to Response Evaluation Criteria in Solid Tumors version 1.0. Thereafter, the effect was confirmed using Gene Expression Omnibus (GEO) and cultured cells.ResultsThere are few reports in FAERS of hypertension in patients treated with omeprazole on bevacizumab. Based on the chart review, patients who used proton pump inhibitors (PPI) had a lower response to treatment than those who did not (response rate: 25% vs 50%). Furthermore, experiments on GEO and cell lines suggested that induction of vascular endothelial growth factor (VEGF) gene expression by PPIs is the cause of the reduced therapeutic effect.ConclusionPPIs prevent hypertension in bevacizumab‐treated patients but may reduce bevacizumab's anti‐tumoral effects by inducing VEGF expression.

Automated feature quantification of Lipiodol as imaging biomarker to predict therapeutic efficacy of conventional transarterial chemoembolization of liver cancer

Conventional transarterial chemoembolization (cTACE) is a guideline-approved image-guided therapy option for liver cancer using the radiopaque drug-carrier and micro-embolic agent Lipiodol, which has been previously established as an imaging biomarker for tumor response. To establish automated quantitative and pattern-based image analysis techniques of Lipiodol deposition on 24 h post-cTACE CT as biomarker for treatment response. The density of Lipiodol deposits in 65 liver lesions was automatically quantified using Hounsfield Unit thresholds. Lipiodol deposition within the tumor was automatically assessed for patterns including homogeneity, sparsity, rim, and peripheral deposition. Lipiodol deposition was correlated with enhancing tumor volume (ETV) on baseline and follow-up MRI. ETV on baseline MRI strongly correlated with Lipiodol deposition on 24 h CT (p < 0.0001), with 8.22% ± 14.59 more Lipiodol in viable than necrotic tumor areas. On follow-up, tumor regions with Lipiodol showed higher rates of ETV reduction than areas without Lipiodol (p = 0.0475) and increasing densities of Lipiodol enhanced this effect. Also, homogeneous (p = 0.0006), non-sparse (p < 0.0001), rim deposition within sparse tumors (p = 0.045), and peripheral deposition (p < 0.0001) of Lipiodol showed improved response. This technical innovation study showed that an automated threshold-based volumetric feature characterization of Lipiodol deposits is feasible and enables practical use of Lipiodol as imaging biomarker for therapeutic efficacy after cTACE.

Luminol Chemiluminescence Reports Photodynamic Therapy‐Generated Neutrophil Activity In Vivo and Serves as a Biomarker of Therapeutic Efficacy

Inflammatory cells, most especially neutrophils, can be a necessary component of the antitumor activity occurring after administration of photodynamic therapy. Generation of neutrophil responses has been suggested to be particularly important in instances when the delivered photodynamic therapy (PDT) dose is insufficient. In these cases, the release of neutrophil granules and engagement of antitumor immunity may play an important role in eliminating residual disease. Herein, we utilize invivo imaging of luminol chemiluminescence to noninvasively monitor neutrophil activation after PDT administration. Studies were performed in the AB12 murine model of mesothelioma, treated with Photofrin-PDT. Luminol-generated chemiluminescence increased transiently 1h after PDT, followed by a subsequent decrease at 4h after PDT. The production of luminol signal was not associated with the influx of Ly6G+ cells, but was related to oxidative burst, as an indicator of neutrophil function. Most importantly, greater levels of luminol chemiluminescence 1h after PDT were prognostic of a complete response at 90days after PDT. Taken together, this research supports an important role for early activity by Ly6G+ cells in the generation of long-term PDT responses in mesothelioma, and it points to luminol chemiluminescence as a potentially useful approach for preclinical monitoring of neutrophil activation by PDT.

Changes in Membrane Protein Clustering in Peripheral Lymphocytes in an Animal Model of Depression Parallel Those Observed in Naïve Depression Patients: Implications for the Development of Novel Biomarkers of Depression.

Naïve depression patients show alterations in serotonin transporter (SERT) and serotonin 2A (5HT2A) receptor clustering in peripheral lymphocytes, and these alterations have been proposed as a biomarker of therapeutic efficacy in major depression. Repeated corticosterone (CORT) induces a consistent depression-like phenotype and has been widely used as an animal model to study neurobiological alterations underlying the depressive symptoms. In this experiment, we used the CORT paradigm to evaluate whether depression-like behavior is associated with similar changes in the pattern of SERT and 5HT2A membrane protein clustering as those observed in depression patients. We also analyzed the clustering of other proteins expressed in lipid rafts in lymphocytes. Rats received daily CORT or vehicle injections for 21 consecutive days. Afterward they underwent the forced swim test to evaluate depression-like behavior, and isolated lymphocytes were analyzed by immunocytochemistry coupled to image-analysis to study clustering parameters of the SERT, 5HT2A receptor, dopamine transporter (DAT), Beta2 adrenergic receptor (β2AR), NMDA 2B receptor (NR2B), Pannexin 1 (Pnx1), and prion cellular protein (PrPc). Our results showed that CORT increases the size of protein clusters for all proteins with the exception of β 2AR, which is decreased. CORT also increased the number of clusters for Pnx1 and PrPc only. Overall, these results indicate that alterations in SERT and 5HT2A protein clustering in naïve depression patients are paralleled by changes seen in an animal model of depression. The CORT paradigm may be a useful screen for examining additional proteins in lymphocytes as a preliminary step prior to their analysis as biomarkers of depression in human blood samples.

Comparative study of two protocols for quantitative image-analysis of serotonin transporter clustering in lymphocytes, a putative biomarker of therapeutic efficacy in major depression

BackgroundThe pattern of serotonin transporter clustering on the plasma membrane of lymphocytes extracted from human whole blood samples has been identified as a putative biomarker of therapeutic efficacy in major depression. Here we evaluated the possibility of performing a similar analysis using blood smears obtained from rats, and from control human subjects and depression patients. We hypothesized that we could optimize a protocol to make the analysis of serotonin protein clustering in blood smears comparable to the analysis of serotonin protein clustering using isolated lymphocytes.ResultsOur data indicate that blood smears require a longer fixation time and longer times of incubation with primary and secondary antibodies. In addition, one needs to optimize the image analysis settings for the analysis of smears. When these steps are followed, the quantitative analysis of both the number and size of serotonin transporter clusters on the plasma membrane of lymphocytes is similar using both blood smears and isolated lymphocytes.ConclusionsThe development of this novel protocol will greatly facilitate the collection of appropriate samples by eliminating the necessity and cost of specialized personnel for drawing blood samples, and by being a less invasive procedure. Therefore, this protocol will help us advance the validation of membrane protein clustering in lymphocytes as a biomarker of therapeutic efficacy in major depression, and bring it closer to its clinical application.

Endothelial progenitor cell number and ERK phosphorylation serve as predictive and prognostic biomarkers in advanced hepatocellular carcinoma patients treated with sorafenib

ABSTRACTSorafenib is an oral anti-angiogenic multi-kinase inhibitor used for systemic therapy in patients with advanced hepatocellular carcinoma (HCC) who are not suitable candidates for surgery or liver transplantation. An earlier study conducted with HCC tumor tissue suggested that ERK phosphorylation (pERK), a downstream target of sorafenib, may serve as a potential biomarker for therapeutic efficacy of sorafenib. However, no study thus far has utilized a minimal invasive procedure to predict HCC patient responsiveness to sorafenib. We evaluated the biomarker utility of circulating endothelial progenitor cells (EPCs) frequency and intracellular pERK levels in EPCs in peripheral blood obtained pre- and post-sorafenib therapy or after transarterial chemoembolistaion (TACE). A statistically significant reduction in the level of ERK phosphorylation and in the absolute number of EPCs was detected following in vivo sorafenib treatment (p < 0 .01 for both). In contrast, the decrease in the level of ERK phosphorylation and EPC number was either marginally significant or insignificant in patients treated with TACE (p = 0.05 and 0.06, respectively). In vitro sorafenib treatment of pre- and post-samples from the same patient cohort inhibited ERK phosphorylation levels in EPCs and decreased the number of EPCs at all doses tested (p = 0.01). Our findings support that the evaluation of both the circulating EPC frequency and the level of ERK phosphorylation in EPCs may serve as potential non-invasive biomarkers of sorafenib efficacy, both as predictor of treatment outcome and efficacy during drug treatment.

Abstract C13: Direct binding of ERα to YB-1 suppresses HER2 expression in human breast cancer

Abstract [Background] ERα and HER2 are two major biomarkers of therapeutic efficacy in breast cancer patients. Y-box binding protein YB-1 is an oncoprotein involved in breast cancer and a transcription factor for HER2/ErbB2. However, regulatory mechanisms of ERα and HER2 expression by YB-1 are largely unknown. In our present study, we examined how nuclear YB-1 regulates expression of HER2 and ERα in breast cancer cells. [Materials and methods] We established YB-1/Tet-On system in which nuclear YB-1 expression was induced by doxycycline, and examined how YB-1 could modulate expression of HER2 and ERα in breast cancer cells. Furthermore, we established the ERα/Tet-On system, in which ERα expression was markedly induced after treatment with doxycycline. To assess whether the YB-1-HER2-ERα correlation was affected by menopause, we analyzed biopsy samples of 116 premenopausal and 114 postmenopausal patients, who had not received any therapeutic drugs, by IHC. [Results] We first examined whether YB-1 regulates expression of ERα and HER2 by using various human breast cancer cell lines, and observed following findings. (1) Nuclear YB-1 overexpression increased HER2 expression and decreases ERα expression, while HER2 expression was suppressed by estradiol and enhanced by anti-estrogen drugs. (2) ERα binding to YB-1 suppressed YB-1 binding to the HER2 promoter region. Furthermore, binding of YB-1 to ERα was enhanced by estradiol and suppressed by anti-estrogen drugs. (3) YB-1 induced proteasomal degradation of ERα when both interact directly. We have next examined whether expression of HER2, nuclear YB-1, and ERα are significantly associated by IHC analysis of biopsy samples of breast cancers. In breast cancers of postmenopausal, but not premenopausal patients, nuclear YB-1 expression was positively correlated with HER2 expression and negatively correlated with ERα expression. [Conclusions] In our study, we presented a new finding that YB-1 promoted proteasomal degradation of ERα by direct interaction and that YB-1-induced HER2 expression was suppressed by ERα. Furthermore, in breast tumors of postmenopausal patients, nuclear YB-1 expression was positively correlated with HER2 expression and negatively correlated with ERα expression. Therefore, this study could contribute to further development of optimized endocrine- and HER2- targeted therapeutics against breast cancer. Citation Format: Tomohiro Shibata, Kosuke Watari, Hiroto Izumi, Akihiko Kawahara, Satoshi Hattori, Chihiro Fukumitsu, Yuichi Murakami, Ryuji Takahashi, Uhi Toh, Ken-ichi Ito, Maki Tanaka, Masayoshi Kage, Michihiko Kuwano, Mayumi Ono. Direct binding of ERα to YB-1 suppresses HER2 expression in human breast cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C13.

Lymphocytosis as a response biomarker of natalizumab therapeutic efficacy in multiple sclerosis

Background: Natalizumab is an effective therapy in relapsing–remitting multiple sclerosis (RRMS), as it reduces lymphocyte transmigration through the blood–brain barrier (BBB) and induces lymphocytosis. Objectives: To analyse natalizumab-induced lymphocytosis (NIL) as a biomarker of drug efficacy. Materials and methods: We enrolled 50 relapsing–remitting (RR) and progressive–relapsing (PR) natalizumab-treated patients who had received at least 16 infusions and had been tested for lymphocyte count 24 hours before each administration. Clinical, MRI and hematological data were collected. Patients were divided into responders and sub-optimal responders according to the experience of at least one clinical and/or instrumental relapse during the treatment. Results: In 15 (30%) patients, an instrumental/clinical (14) or only instrumental (one) relapse occurred. We found a statistically significant difference in the mean percentage of the lymphocytes between the two groups over the first ten administrations (p=0.04). The comparison between the time-to-relapse in the groups with high and low levels of lymphocytes showed that the group with a low NIL had a greater risk of relapse (p=0.03). Conclusions: We suggest that NIL could be a biomarker of therapeutic efficacy in patients with RRMS treated with natalizumab, and that the risk of relapse may be higher in patients with a lower-than-expected NIL.

New Indings in Methotrexate Pharmacology - Diagnostic Possibilities and Impact on Clinical Care

Methotrexate is an anti-cancer drug used to treat several malignancies including pediatric acute lymphoblastic leukemia and choriocarcinoma. Despite recent advances in cancer chemotherapy, it remains a mainstay of therapy since its discovery in the early second half of the previous century. Moreover, low-dose methotrexate is a gold standard antirheumatic drug in the treatment of rheumatoid arthritis, psoriasis, systemic scleroderma and other autoimmune disorders. Side effects of methotrexate treatment are well known and described; however, their occurrence may often be unpredictable due to lack of specific biomarkers of toxicity. Methotrexate plasma levels are routinely monitored by therapeutic drug monitoring, nevertheless, occurrence and concentrations of its metabolites are not measured. During methotrexate treatment 7- hydroxymethotrexate and 2,4- diamino- N10- mehylpteroic acid appear in plasma. The latter can further be hydroxylated and glucuronidated resulting in five possible extracellular methotrexate metabolites. In addition, methotrexate is intracellularly converted to its active polyglutamylated forms. Therapeutic efficacy is dependent on formation of methotrexate polyglutamates as it keeps intracellular pool of the drug and enhances its affinity towards various target enzymes. In this study, we describe pharmacokinetic and pharmacodynamic characteristics of methotrexate metabolites. We also review methotrexate blood brain barrier transport to cerebrospinal fluid regarding its use in the prevention of leukemic central nervous system involvement and management of methotrexate toxicity with the use of carboxypeptidase- G2. Finally, we discuss laboratory methods for monitoring methotrexate metabolites and benefits of simultaneous determination of methotrexate and metabolites as possible biomarkers of therapeutic efficacy and clinical toxicity.

Abstract NG02: Rational drug combinations to improve anti-EGFR targeted therapies in metastatic colorectal cancer

Abstract NG02: Rational drug combinations to improve anti-EGFR targeted therapies in metastatic colorectal cancer

P.13.6 Nuclear Magnetic Resonance imaging and spectroscopy provide quantitative indices of disease severity in forearms of boys with Duchenne Muscle Dystrophy

Non-invasive measurements and quantitative evaluation of the natural course of disease need to be established in anticipation of replacement therapy in Duchenne muscular dystrophy (DMD). A cohort of 23 DMD boys (6–18years, 14 non-ambulant), were enrolled specifically to characterize disease progression of upper limbs, to be targeted in future therapeutic trials. Prior studies in the GRMD canine model showed that Nuclear Magnetic Resonance imaging (NMRI) and phosphorous spectroscopy (NMRS) could provide quantitative indices which graded with therapeutic dose. A similar approach was implemented in patients, who were examined in a 3T-60cm Siemens Magnetom TRIO system, with the arm along the body. The two arms were examined in separate sessions, to be repeated yearly, comprising NMRI (measurement of T2 of muscle water, and of fat fraction by 3-point Dixon imaging) and NMRS of phosphate metabolites. Each item lasted ∼20min. Twelve indices were analysed: –2 in NMRI: %fat signal (%F), muscle water T2 (deconvoluted from fat) –10 in NMRS: 8 ratios of metabolites combining: ATP, phosphocreatine, phospho mono- and di-esters and two pools of inorganic phosphate: cytosolic (Pia) and an anomalous alkaline pool present in dystrophic muscle (Pib), and 2 indices for respective pH values. T2 was above laboratory norms in 15% of cases, % F exceeded 10% of signal in 70% of cases and correlated to patient age ( R =.58, P R =.38 to .46, P F , ( R =.46 to .77, P Quantitative NMRI and NMRS provided a variety of indices which were abnormal in forearms of DMD patients, covering a broad range of fat infiltration, and metabolic abnormalities which graded together and with patient age and could provide biomarkers of therapeutic efficacy.

Plasma microRNAs serve as biomarkers of therapeutic efficacy and disease progression in hypertension‐induced heart failure

Recent studies have shown that microRNAs (miRNAs), besides being potent regulators of gene expression, can additionally serve as circulating biomarkers of disease. The aim of this study is to determine if plasma miRNAs can be used as indicators of disease progression or therapeutic efficacy in hypertension-induced heart disease. In order to define circulating miRNAs that change during hypertension-induced heart failure and that respond to therapeutic treatment, we performed miRNA arrays on plasma RNA from hypertensive rats that show signs of heart failure. Array analysis indicated that approximately one-third of the miRNAs on the array are detectable in plasma. Quantitative real-time polymerase chain reaction (PCR) analysis for a selected panel of miRNAs indicated that circulating levels of miR-16, miR-20b, miR-93, miR-106b, miR-223, and miR-423-5p were significantly increased in response to hypertension-induced heart failure, while this effect was blunted in response to treatment with antimiR-208a as well as an ACE inhibitor. Moreover, treatment with antimiR-208a resulted in a dramatic increase in one miRNA, miR-19b. A time course study indicated that several of these miRNA changes track with disease progression. Circulating levels of miRNAs are responsive to therapeutic interventions and change during the progression of hypertension-induced heart disease.

MRI apparent diffusion coefficient in a murine orthotopic glioblastoma model as a clinically translatable early readout of efficacy for AMG 595, an antibody drug conjugate targeting EGFRvIII.

11095 Background: Epidermal growth factor receptor variant III (EGFRvIII) is a constitutively active mutant of EGFR present in thirty to fifty percent of glioblastoma (GBM) patients. AMG 595, currently in Phase I trials, is composed of a fully human anti-EGFRvIII-specific antibody conjugated to the maytansinoid DM1 via a non-cleavable linker. The MRI apparent diffusion coefficient (MRI ADC) has been shown to correlate with tissue cellularity, and changes in MRI ADC can be an early indicator of therapeutic efficacy. The aim of this work is to evaluate MRI ADC as a clinically translatable early readout of tissue changes due to AMG 595 treatment in a murine orthotopic GBM model. Methods: D317 human GBM cells were intracranially injected into in female CB17 SCID mice at Day 0. Mice were randomized at Day 7, using tumor volumes calculated by MRI, and were treated with vehicle, 6.5, 11, or 22 mg/kg AMG 595 i.v. twice per week, or temozolomide 10 mg/kg p.o. daily five days per week (N=8/group). MRI was repeated at days 14 and 21. Tumor volumes were manually traced on multi-slice T2-weighted RARE images covering the entire tumor volume. The mean MRI apparent diffusion coefficients for each tumor in the vehicle and 22 mg/kg AMG 595-treated groups were calculated from diffusion-weighted spin echo images (b = 100-1200 s/mm2). Results: A dose-dependent effect of AMG 595 on tumor volume was observed at Day 21; growth was inhibited in both the temozolomide and AMG 595-treated groups (22 and 11 mg/kg) relative to vehicle (p&lt;0.0001). At Day 14, this significant treatment effect on tumor volume was not yet detectable. However, mean MRI ADC values were already significantly higher in the AMG 595 (22 mg/kg) treated group than in the vehicle group (23% higher at Day 14, p&lt;0.01 vs vehicle; 32% higher at Day 21, p&lt;0.0001 vs vehicle). The increase in MRI ADC in the AMG 595-treated group preceded observable tumor growth inhibition in the AMG 595-treated animals. Conclusions: Increases in tumor MRI ADC in response to AMG 595 treatment precede measurable inhibition of tumor growth, supporting the use of MRI ADC as a clinically relevant early biomarker for therapeutic efficacy.

Dichotomous roles for the orphan nuclear receptor NURR1 in breast cancer

BackgroundNR4A orphan nuclear receptors are involved in multiple biological processes which are important in tumorigenesis such as cell proliferation, apoptosis, differentiation, and glucose utilization. The significance of NR4A family member NURR1 (NR4A2) in breast cancer etiology has not been elucidated. The purpose of this study was to ascertain the impact of NURR1 expression on breast transformation, tumor growth, and breast cancer patient survival.MethodsWe determined the expression of NURR1 in normal breast versus breast carcinoma in tissue microarrays (immunohistochemistry), tissue lysates (immunoblot), and at the mRNA level (publically available breast microarrays). In addition NURR1 expression was compared among breast cancer patients in cohorts based on p53 expression, estrogen receptor α expression, tumor grade, and lymph node metastases. Kaplan-Meier survival plots were used to determine the correlation between NURR1 expression and relapse free survival (RFS). Using shRNA-mediated silencing, we determined the effect of NURR1 expression on tumor growth in mouse xenografts.ResultsResults from breast cancer tissue arrays demonstrate a higher NURR1 expression in the normal breast epithelium compared to breast carcinoma cells (p ≤ 0.05). Among cases of breast cancer, NURR1 expression in the primary tumors was inversely correlated with lymph node metastases (p ≤ 0.05) and p53 expression (p ≤ 0.05). Clinical stage and histological grade were not associated with variation in NURR1 expression. In gene microarrays, 4 of 5 datasets showed stronger mean expression of NURR1 in normal breast as compared to transformed breast. Additionally, NURR1 expression was strongly correlated with increase relapse free survival (HR = 0.7) in a cohort of all breast cancer patients, but showed no significant difference in survival when compared among patients whom have not been treated systemically (HR = 0.91). Paradoxically, NURR1 silenced breast xenografts showed significantly decreased growth in comparison to control, underscoring a biphasic role for NURR1 in breast cancer progression.ConclusionsNURR1 function presents a dichotomy in breast cancer etiology, in which NURR1 expression is associated with normal breast epithelial differentiation and efficacy of systemic cancer therapy, but silencing of which attenuates tumor growth. This provides a strong rationale for the potential implementation of NURR1 as a pharmacologic target and biomarker for therapeutic efficacy in breast cancer.