In Vitro Mechanical Stimulation to Reproduce the Pathological Hallmarks of Human Cardiac Fibrosis on a Beating Chip and Predict The Efficacy of Drugs and Advanced Therapies

Cardiac fibrosis is one of the main causes of heart failure, significantly contributing to mortality. The discovery and development of effective therapies able to heal fibrotic pathological symptoms thus remain of paramount importance. Micro-physiological systems (MPS) are recently introduced as promising platforms able to accelerate this finding. Here a 3D in vitro model of human cardiac fibrosis, named uScar, is developed by imposing a cyclic mechanical stimulation to human atrial cardiac fibroblasts (AHCFs) cultured in a 3D beating heart-on-chip and exploited to screen drugs and advanced therapeutics. The sole provision of a cyclic 10% uniaxial strain at 1 Hz to the microtissues is sufficient to trigger fibrotic traits, inducing a consistent fibroblast-to-myofibroblast transition and an enhanced expression and production of extracellular matrix (ECM) proteins. Standard of care anti-fibrotic drugs (i.e., Pirfenidone and Tranilast) are confirmed to be efficient in preventing the onset of fibrotic traits in uScar. Conversely, the mechanical stimulation applied to the microtissues limit the ability of a miRNA therapy to directly reprogram fibroblasts into cardiomyocytes (CMs), despite its proved efficacy in 2D models. Such results demonstrate the importance of incorporating in vivo-like stimulations to generate more representative 3D in vitro models able to predict the efficacy of therapies in patients.

Correction to: Direct Reprogramming of Adult Human Cardiac Fibroblasts into Induced Cardiomyocytes Using miRcombo

This chapter was previously published as non-Open Access. Under the request of the authors the chapter is now converted to Open Access and is available as Open Access under a CC BY 4.0 license.

Lipoplexes for effective in vitro delivery of microRNAs to adult human cardiac fibroblasts for perspective direct cardiac cell reprogramming

Design of nanocarriers for efficient miRNA delivery can significantly improve miRNA-based therapies. Lipoplexes based on helper lipid, dioleoyl phosphatidylethanolamine (DOPE) and cationic lipid [2-(2,3-didodecyloxypropyl)-hydroxyethyl] ammonium bromide (DE) were formulated to efficiently deliver miR-1 or a combination of four microRNAs (miRcombo) to adult human cardiac fibroblasts (AHCFs). Lipoplexes with amino-to-phosphate groups ratio of 3 (N/P 3) showed nanometric hydrodynamic size (372 nm), positive Z-potential (40 mV) and high stability under storage conditions. Compared to commercial DharmaFECT1 (DF), DE-DOPE/miRNA lipoplexes showed superior miRNA loading efficiency (99 % vs. 64 %), and faster miRNA release (99 % vs. 82 % at 48 h). DE-DOPE/miR-1 lipoplexes showed superior viability (80-100 % vs. 50 %) in AHCFs, a 2-fold higher miR-1 expression and Twinfilin-1 (TWF-1) mRNA downregulation. DE-DOPE/miRcombo lipoplexes significantly enhanced AHCFs reprogramming into induced cardiomyocytes (iCMs), as shown by increased expression of CM markers compared to DF/miRcombo.

Cardiac Tissue-like 3D Microenvironment Enhances Route towards Human Fibroblast Direct Reprogramming into Induced Cardiomyocytes by microRNAs

The restoration of cardiac functionality after myocardial infarction represents a major clinical challenge. Recently, we found that transient transfection with microRNA combination (miRcombo: miR-1, miR-133, miR-208 and 499) is able to trigger direct reprogramming of adult human cardiac fibroblasts (AHCFs) into induced cardiomyocytes (iCMs) in vitro. However, achieving efficient direct reprogramming still remains a challenge. The aim of this study was to investigate the influence of cardiac tissue-like biochemical and biophysical stimuli on direct reprogramming efficiency. Biomatrix (BM), a cardiac-like extracellular matrix (ECM), was produced by in vitro culture of AHCFs for 21 days, followed by decellularization. In a set of experiments, AHCFs were transfected with miRcombo and then cultured for 2 weeks on the surface of uncoated and BM-coated polystyrene (PS) dishes and fibrin hydrogels (2D hydrogel) or embedded into 3D fibrin hydrogels (3D hydrogel). Cell culturing on BM-coated PS dishes and in 3D hydrogels significantly improved direct reprogramming outcomes. Biochemical and biophysical cues were then combined in 3D fibrin hydrogels containing BM (3D BM hydrogel), resulting in a synergistic effect, triggering increased CM gene and cardiac troponin T expression in miRcombo-transfected AHCFs. Hence, biomimetic 3D culture environments may improve direct reprogramming of miRcombo-transfected AHCFs into iCMs, deserving further study.

Bioengineering Methods in MicroRNA-Mediated Direct Reprogramming of Fibroblasts Into Cardiomyocytes

Ischemic heart disease is the major cause of mortality worldwide. Despite the most recent pharmacological progresses, cardiac regeneration is yet not possible, and heart transplantation is the only therapeutic option for end-stage heart failure. Traditional cardiac regenerative medicine approaches, such as cell therapies and tissue engineering, have failed in the obtainment of human functional cardiac tissue, mainly due to unavailability of high quantities of autologous functional cardiomyocytes (CMs), low grafting efficiency, and/or arrhythmic events. Direct reprogramming (DR) of fibroblasts into induced CMs (iCMs) has emerged as a new promising approach for myocardial regeneration by in situ transdifferentiation or providing additional CM source for cell therapy. Among available DR methods, non-viral transfection with microRNAs (miRcombo: miR-1, miR-133, miR-208, and miR-499) appears promising for future clinical translation. MiRcombo transfection of fibroblasts could be significantly improved by the development of safe nanocarriers, efficiently delivering their cargo to target cells at the required stoichiometric ratio and overall dose in due times. Newly designed in vitro 3D culture microenvironments, providing biomimetic biophysical and biochemical stimuli to miRcombo-transfected cells, significantly increase the yield of fibroblast transdifferentiation into iCMs, enhancing CM gene expression. Epigenetic regulation of gene expression programs, critical to cell lineage commitment, can also be promoted by the administration of specific anti-inflammatory and anti-fibrotic soluble factors, helping in suppressing fibroblast signature. The aim of this mini-review is to introduce the readers to a relatively unknown field of cardiac research integrating bioengineering tools as relevant for the progress of miRNA-mediated cardiac DR.

MicroRNA-Mediated Direct Reprogramming of Human Adult Fibroblasts Toward Cardiac Phenotype

Modulation of microRNA expression holds the promise to achieve direct reprogramming of fibroblasts into cardiomyocyte-like cells as a new strategy for myocardial regeneration after ischemic heart disease. Previous reports have shown that murine fibroblasts can be directly reprogrammed into induced cardiomyocytes (iCMs) by transient transfection with four microRNA mimics (miR-1, 133, 208, and 499, termed "miRcombo"). Hence, study on the effect of miRcombo transfection on adult human cardiac fibroblasts (AHCFs) deserves attention in the perspective of a future clinical translation of the approach. In this brief report, we studied for the first time whether miRcombo transient transfection of AHCFs by non-viral vectors might trigger direct reprogramming of AHCFs into cardiomyocyte-like cells. Initially, efficient miRNA delivery to cells was demonstrated through the use of a commercially available transfection agent (DharmaFECT1). Transient transfection of AHCFs with miRcombo was found to upregulate early cardiac transcription factors after 7 days post-transfection and cardiomyocyte specific marker cTnT after 15 days post-transfection, and to downregulate the expression of fibroblast markers at 15 days post-transfection. The percentage of cTnT-positive cells after 15 days from miRcombo transfection was ∼11%, as evaluated by flow cytometry. Furthermore, a relevant percentage of miRcombo-transfected AHCFs (∼38%) displayed spontaneous calcium transients at 30 days post-transfection. Results evidenced the role of miRcombo transfection on triggering the trans differentiation of AHCFs into iCMs. Although further investigations are needed to achieve iCM maturation, early findings from this study pave the way toward new advanced therapies for human cardiac regeneration.

Natural History of Perianal Fistulising Lesions in Patients With Elderly-onset Crohn's Disease: A Population-based Study

INTRODUCTION

Most studies of elderly-onset Crohn's disease [CD; diagnosed in patients aged 60 or over] have described a mild course. However, data on the natural history of perianal fistulising CD [pfCD] in this population are scarce. In a population-based cohort study, we described the prevalence, natural history, and treatment of pfCD in patients with elderly-onset CD vs patients with paediatric-onset CD.

METHOD

All patients diagnosed with CD at or after the age of 60 between 1988 and 2006, were included [n = 372]. Logistic regression, Cox models, and a nested case-control method were used to identify factors associated with pfCD.

RESULTS

A total of 34 elderly patients [9% of the 372] had pfCD at diagnosis. After a median follow-up of 6 years (interquartile range [IQR]: 3; 10), 59 patients [16%] had pfCD; the same prevalence [16%] was observed in paediatric-onset patients. At last follow-up, anal incontinence was more frequent in elderly patients with pfCD than in elderly patients without pfCD [22% vs 4%, respectively; p < 10-4]. Rectal CD at diagnosis was associated with pfCD: hazard ratio (95% confidence interval [CI] = 2.8 [1.6-5.0]). Although 37% of the patients received immunosuppressants and 17% received anti-tumour necrosis factor agents, 24% [14 out of 59] had a definitive stoma at last follow-up.

CONCLUSION

During the first 6 years of disease, the prevalence of pfCD was similar in elderly and paediatric patients. Rectal involvement was associated with the appearance of pfCD in elderly-onset patients. Around a quarter of patients with elderly-onset CD will have a stoma. Our results suggest that treatment with biologics should be evaluated in these patients.

MicroRNA delivery through nanoparticles

MicroRNAs (miRNAs) are attracting a growing interest in the scientific community due to their central role in the etiology of major diseases. On the other hand, nanoparticle carriers offer unprecedented opportunities for cell specific controlled delivery of miRNAs for therapeutic purposes. This review critically discusses the use of nanoparticles for the delivery of miRNA-based therapeutics in the treatment of cancer and neurodegenerative disorders and for tissue regeneration. A fresh perspective is presented on the design and characterization of nanocarriers to accelerate translation from basic research to clinical application of miRNA-nanoparticles. Main challenges in the engineering of miRNA-loaded nanoparticles are discussed, and key application examples are highlighted to underline their therapeutic potential for effective and personalized medicine.

Impact of Biomaterials on Differentiation and Reprogramming Approaches for the Generation of Functional Cardiomyocytes

The irreversible loss of functional cardiomyocytes (CMs) after myocardial infarction (MI) represents one major barrier to heart regeneration and functional recovery. The combination of different cell sources and different biomaterials have been investigated to generate CMs by differentiation or reprogramming approaches although at low efficiency. This critical review article discusses the role of biomaterial platforms integrating biochemical instructive cues as a tool for the effective generation of functional CMs. The report firstly introduces MI and the main cardiac regenerative medicine strategies under investigation. Then, it describes the main stem cell populations and indirect and direct reprogramming approaches for cardiac regenerative medicine. A third section discusses the main techniques for the characterization of stem cell differentiation and fibroblast reprogramming into CMs. Another section describes the main biomaterials investigated for stem cell differentiation and fibroblast reprogramming into CMs. Finally, a critical analysis of the scientific literature is presented for an efficient generation of functional CMs. The authors underline the need for biomimetic, reproducible and scalable biomaterial platforms and their integration with external physical stimuli in controlled culture microenvironments for the generation of functional CMs.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents

OBJECTIVES

Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period.

METHODS

Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification.

RESULTS

1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/10⁵ for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/10⁵ (+126%; P<0.001) and for UC, from 1.6 to 4.1/10⁵ (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC.

CONCLUSIONS

In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

Extra-intestinal Manifestations at Diagnosis in Paediatric- and Elderly-onset Ulcerative Colitis are Associated With a More Severe Disease Outcome: A Population-based Study

BACKGROUND AND AIMS

Data on extra-intestinal manifestations [EIM] and their impact on the disease course of ulcerative colitis [UC] in population-based cohorts are scarce, particularly in paediatric- and elderly-onset UC patients. The aims of this population-based study were to assess: 1] the occurrence of EIM in paediatric- and elderly-onset UC; 2] the factors associated with EIM; and 3] their impact on long-term disease outcome.

METHODS

Paediatric-onset [< 17 years at diagnosis] and elderly-onset UC patients [> 60 years at diagnosis] from a French prospective population-based registry [EPIMAD] were included. Data on EIM and other clinical factors at diagnosis and at maximal follow-up were collected.

RESULTS

In all, 158 paediatric- and 470 elderly-onset patients were included [median age at diagnosis 14.5 and 68.8 years, median follow-up 11.2 and 6.2 years, respectively]. EIM occurred in 8.9% of childhood- and 3% of elderly-onset patients at diagnosis and in 16.7% and 2.2% of individuals during follow-up [p < 0.01], respectively. The most frequent EIM was joint involvement [15.8% of paediatric onset and 2.6% of elderly-onset]. Presence of EIM at diagnosis was associated with more severe disease course [need for immunosuppressants or biologic therapy or colectomy] in both paediatric- and elderly-onset UC (hazard ratio [HR] = 2.0, 95% confidence interval [CI]: 1.0-4.2; and HR = 2.8, 0.9-7.9, respectively). Extensive colitis was another independent risk factor in both age groups.

CONCLUSIONS

Elderly-onset UC patients had lower risk of EIM either at diagnosis or during follow-up than paediatric-onset individuals. EIM at diagnosis predicted more severe disease outcome, including need for immunosuppressive or biologic therapy or surgery, in both paediatric- and elderly-onset UC.

A graphene oxide pH sensor for wound monitoring

This article describes the fabrication and characterization of a pH sensor for monitoring the wound status. The pH sensitive layer consists of a graphene oxide (GO) layer obtained by drop-casting 5 μΐ of GO dispersion onto the working electrode of a screen-printed substrate. Sensitivity was 31.8 mV/pH with an accuracy of 0.3 unit of pH. Open-circuit potentiometry was carried out to measure pH in an exudate sample. The GO pH sensor proved to be reliable as the comparison with results obtained from a standard glass electrode pH-meter showed negligible differences (<; 0.09 pH units in the worst case) for measurements performed over a period of 4 days.

Abstract P1-01-01: Circulating tumor cell number and CTC-endocrine therapy index predict clinical outcomes in ER positive metastatic breast cancer patients: Results of the COMETI Phase 2 trial

Introduction: Only half of hormone receptor positive (HR+) metastatic breast cancer (MBC) patients (pts) benefit from endocrine therapy (ET). Circulating tumor cells (CTC) are prognostic in pts with MBC using CellSearch® technology. The CTC-endocrine therapy index (CTC-ETI) provides semi-quantitative analyses of CTC-ER (estrogen receptor), BCL2, HER2, and Ki67 expression. We hypothesized that CTC-ETI high (elevated CTC number and/or low expression of ER and BCL2, and high expression of HER2 and Ki-67) might predict resistance to ET in a prospective, multi-institutional clinical trial: COMETI-P2-2012.0 (NCT01701050).

Methods: 121 pts with ER+, HER2 negative (-), and progressive MBC after one or more lines of ET or within 12 months (mos) of completing adjuvant ET, who were initiating a new ET, were enrolled after informed consent. CTC and CTC-ETI were determined as previously reported (Paoletti C et al, CCR 2015) at baseline (BL), 1, 2, 3, and 12 mos, and/or at the time of progression. Imaging was performed every 3 mos. Association of CTC levels and CTC-ETI with patient outcomes (progression free survival (PFS); rapid progression (RP) defined as progression within 3 mos) was assessed using logrank and Fisher's exact tests. Trial design estimated 85 PFS and 51 RP events, providing &gt;90% power (2-sided a=0.05); pts with unsuccessful BL CTC-ETI or ineligible were unevaluable. Only baseline (BL) data are reported in this abstract.

Results: 32% of enrolled pts had progression within 12 mos of completing adjuvant ET, whereas 40%, 20%, and 8% had 1, 2, ≥3 lines of ET for MBC. CTC-ETI was successfully determined in 93% of pts (90% CI, 88% to 97%). CTC were ≥5 CTC/7.5 ml whole blood in 37/108 (34%) pts evaluable for clinical validity. Elevated CTC was associated with worse PFS (median (m) PFS: 3.3 vs. 5.9 mos; P&lt;0.01). Low, intermediate, and high CTC-ETI were observed in 75 (69%), 6 (6%), and 27 (25%) pts, respectively. CTC-ETI was associated with PFS (logrank P&lt;0.01): pts with low, intermediate, and high CTC-ETI had mPFS of 5.7, 8.5, and 2.8 mos, respectively. In the 96 pts eligible for determination, elevated CTC was associated with RP, (65.6% vs. 42.2%; P=0.05) as was CTC-ETI (P=0.003): 79.2% (95% CI, 57.8% to 92.9%) of pts with high CTC-ETI had RP versus 41.2% (95% CI, 29.4% to 53.8%) with low CTC-ETI; in the small group with intermediate CTC-ETI 1 of 4 pts (25%) had RP.

Conclusions: In this multi-institutional, prospective study, CTC-ETI was accurately determined, confirming the previously established analytical validity of the assay, meeting the primary objective of the trial. Elevated CTC and CTC-ETI high compared to low were associated with poor outcomes to ET. CTC-ETI distribution resulted in a small number of patients assigned to the intermediate group, restricting our ability to associate this group with outcomes. These results suggest that CTC-biomarker phenotype and enumeration have clinical validity. CTC-ETI may identify ER+ HER2– MBC pts who are unlikely to benefit from ET and might be better treated with ET in combination with other therapies or proceed to chemotherapy. Further analyses including CTC-ETI at serial time points during ET are planned.

Citation Format: Paoletti C, Regan MM, Liu MC, Marcom PK, Hart LL, Smith II JW, Tedesco KL, Amir E, Krop IE, DeMichele AM, Goodwin PJ, Block M, Aung K, Cannell EM, Darga EP, Baratta PJ, Brown ME, McCormack RT, Hayes DF. Circulating tumor cell number and CTC-endocrine therapy index predict clinical outcomes in ER positive metastatic breast cancer patients: Results of the COMETI Phase 2 trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-01.

Abstract P2-02-19: Somatic genetic profiling of circulating tumor cells (CTC) in metastatic breast cancer (MBC) patients

Introduction: Somatic mutations, including those in TP53, PIK3CA, and estrogen receptor alpha (ESR1), are key to the biology of cancer and response to therapy. Recently, somatic cancer-associated mutations have been identified in circulating cell free plasma tumor DNA (ptDNA). Less is known about the mutation profile of DNA extracted from CTC (CTC-DNA). Since CTC-DNA provides mutational information of single cells, we hypothesize CTC-DNA will complement ptDNA to give greater insight into tumor heterogeneity.

Methods: Patients with ER positive MBC who were enrolled in the Mi CTC-ONCOSEQ, a companion trial to Mi-ONCOSEQ (the Michigan Oncology Sequencing Program), and who had ≥5CTC/7.5 ml whole blood were included. CTC were enriched from white blood cells (WBC) with CellSearch© (CXC kit). CTC and WBC were then purified using DEPArrayTM. DNA from individual CTC and WBC was isolated and subjected to whole genomic amplification (Ampli 1TM WGA). Genetic analysis was performed on individual CTC, pooled CTC and pooled WBC DNA by multiplexed PCR based targeted next generation sequencing (NGS) using the Oncomine Comprehensive Panel (targeting ∼130 onco- and tumor suppressor genes) and the Ion Torrent Proton. All patients had exome sequencing performed on research biopsies of metastases using an Illumina HiSeq 2500 platform.

Results: This pilot study was conducted using high quality DNA from two patients assessed to date. Both patients had lobular carcinoma and as expected harbored somatic, deleterious CDH1 (E-cadherin) mutations (frameshift and non-sense) in both research biopsy and CTC-DNA. These data supported our approach. Patient #1 was TP53 wild type in her research biopsy, but multiple CTC harbored somatic TP53 frame-shift mutations (Table). Patient #2 harbored an ESR1 Y537S mutation in her research biopsy. However, only 4 of 7 CTC also harbored this somatic, heterozygous mutation.

Prioritized mutations in CTCPt#Cell Type (CTC vs WBC), numberGeneMutationVariant fraction (expected 1=homozygous; 0.5=heterozygous)Found in research biopsy?1CTC_A2CDH1p.I584fs1YES CTC_A4  1  CTC_A7  0.54  CTC_pool*  0.74  WBC_pool  0  CTC_A2TP53p.152_156del1NO CTC_A4  1  CTC_A7  0.51  CTC_pool*  0.88  WBC_pool  0 2CTC_A9ESR1p.Y537S0.52YES CTC_D1  0.34  CTC_D2  0.46  CTC_D6  0.65  CTC_pool*  0.35  WBC_pool  0  CTC_A12  0  CTC_D3  0  CTC_D7  0  CTC_A12CDH1p.Q641X1YES CTC_A9  1  CTC_D1  1  CTC_D3  1  CTC_D6  1  CTC_pool*  1  WBC_pool  0 * pool of all CTC

Conclusions: We demonstrate the ability to purify CTC, isolate, and amplify DNA of suitable quality for genetic analysis using a comprehensive targeted sequencing panel. Both known and novel alterations were identified in comparison to research biopsy specimens. This approach allows single cell analysis demonstrating heterogeneity of mutational status in different single cells. Studies of CTC-ESR1 and other genetic abnormalities in patients with known tissue mutations who participated in Mi CTC-ONCOSEQ are now underway.

Citation Format: Paoletti C, Cani AK, Aung K, Darga EP, Cannell EM, Hovelson DH, Yazdani M, Blevins AR, Tokudome N, Larios JM, Thomas DG, Brown ME, Gersch C, Schott AF, Robinson DR, Chinnaiyan AM, Bischoff F, Hayes DF, Rae JM, Tomlins SA. Somatic genetic profiling of circulating tumor cells (CTC) in metastatic breast cancer (MBC) patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-19.

Abstract P3-05-01: Molecular analysis of cancer tissue, circulating tumor cells (CTC) and cell-free plasma tumor DNA (ptDNA) suggests variable mechanisms of resistance to endocrine therapy (ET) in estrogen receptor (ER) positive metastatic breast cancer (MBC)

Introduction: Fifty percent of ER positive MBC patients do not benefit from ET. Potential mechanisms of resistance to ET in this patient population include absence of ER expression by deletion or suppression, alteration in ER signaling pathway genes, or upregulation of multiple growth factor receptor pathways. We hypothesized that genotyping and phenotyping of CTC combined with genomic analysis of ptDNA will provide important insights into the multiple mechanisms of ET resistance and that a set of blood tests might serve as a "liquid biopsy" abrogating the need for tissue specimens.

Methods: Twenty-four patients providing informed consent were enrolled into the Mi CTC-ONCOSEQ study, a companion trial to Mi-ONCOSEQ (the Michigan Oncology Sequencing Program). Seven of these patients (5 with ER immunohistochemistry (IHC) positive and 2 with ER negative cancers) who had available archived primary and metastatic cancer tissue, a research metastatic biopsy for genomic analysis, and who had ≥5CTC/7.5 ml whole blood (WB) characterized for ER protein (CTC-ER) are the focus of this report. All the patients were ET refractory. None of them was progressing on fulvestrant at the time of study entry. CTC enumeration and phenotyping was performed with CellSearch©. Circulating ptDNA was analyzed by droplet digital polymerase chain reaction (ddPCR). ER status from archived tissue was obtained from chart review. ER mRNA expression was determined in the research biopsy of metastatic tissue by using quantitative RNA sequencing. Mutational status of ER gene, ESR1, was determined by Next-gen Sequencing using the Illumina HiSeq 2500 platform.

Results: The 2 control patients with triple negative breast cancer had negative CTC-ER. Discordance between CTC-ER and tissue ER by IHC was observed (Table). Two of the 5 ER positive patients retained CTC-ER positivity (39% and 19% of the CTC). One of them (#7) harbored an ESR1 mutation in the research biopsy tissue and in ptDNA, whereas the other (#14) had wild type (WT) ESR1. CTC-ER protein levels in patients #12, 17 and 24 were negative. All had WT ESR1 in the research biopsy tissue. Of note, patient #12 had WT ESR1 in the research biopsy, but an ESR1 mutation was detected in her ptDNA.

Pt#CTC-ER Tissue-ER  ESR1 status in research biopsyESR1 status in ptDNA N[deg]CTC/7.5ml WB% CTC-ER +Primary by IHCMet by IHCMet research biopsy by mRNA  71839%+++Y537SY537S141619%+NA+WTWT12130%+++WTD538G17160%++weakly+WTWT242750%+weakly+weakly+WTWT

Conclusions: These exploratory data suggest heterogeneous mechanisms of resistance to ET in patients with previously determined ER-positive MBC, including ESR1 mutations in ER positive cases (seen in 2 patients) and loss of ER expression (seen in CTC of 3 patients). In contrast, other cancers continue to express WT ESR1, and therefore must have developed alternative mechanisms of resistance. At least 2 of these mechanisms can be detected and monitored with complementary circulating assays: CTC and ptDNA. Further investigations are needed to understand the heterogeneous mechanisms of resistance to ET.

Citation Format: Paoletti C, Aung K, Cannell EM, Darga EP, Chu D, Kidwell KM, Thomas DG, Tokudome N, Brown ME, McNutt LM, Gersch C, Schott AF, Park BH, Robinson DR, Chinnaiyan AM, Rae JM, Hayes DF. Molecular analysis of cancer tissue, circulating tumor cells (CTC) and cell-free plasma tumor DNA (ptDNA) suggests variable mechanisms of resistance to endocrine therapy (ET) in estrogen receptor (ER) positive metastatic breast cancer (MBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-05-01.

Abstract P1-04-01: Significance of circulating tumor cells in metastatic triple negative breast cancer: Results of an open label, randomized, phase II trial of nanoparticle albumin-bound paclitaxel with or without the anti-death receptor 5 tigatuzumab (TBCRC 019)

Background: Circulating Tumor cells (CTCs) are prognostic at baseline and first follow-up in patients with metastatic breast cancer (MBC). Using the most commonly used assay (CellSearch®), we have previously reported the ability to detect apoptotic vs. non-apoptotic CTCs in patients with MBC. However, there has been concern regarding the performance of the CellSearch® assay in patients with triple negative (TN) MBC. We hypothesized that CellSearch® is an effective assay in patients with TN MBC, and that CTC-apoptosis might further separate prognosis. Therefore, we studied CTCs in patients with TN MBC who participated in a prospective randomized phase II trial testing for activity of tigatuzumab (TIG) in combination with nanoparticle albumin-bound paclitaxel (nab-PAC) conducted by the Translational Breast Cancer Research Consortium (overall results reported by Forero A., et al, ASCO 2013).

Methods: Whole blood (WB) was drawn into a CellSave tube at baseline, day 15, and day 29 and CTC counts were determined using the CXC CellSearch® kit. Apoptosis was characterized by staining with a monoclonal antibody that detects a neo-epitope on fragmented cytokeratin (M-30) and independently by visual inspection (nucleic condensation and/or fragmentation, as well as granular cytokeratin). Association between levels of CTCs and CTC-apoptosis with the overall response rate (ORR) and progression free survival (PFS) at baseline, day 15, and day 29 was assessed using logistic regression, Kaplan Meier curves, and Cox proportional hazards modeling.

Results: Of the 60 patients entered into the trial, 52 were evaluable for CTCs. Of these, 19/52 (36.5%), 14/52 (26.9%), and 13/49 (26.5%) had elevated CTCs (≥5CTC/7.5 ml WB) at baseline, day 15, and day 29, respectively. Patients with elevated CTCs at each time point had worse PFS than patients with low or no CTCs. Hazard rates (HR) at baseline, day 15, and day 29 were 2.38 (95% CI: 1.27-4.45, p = 0.007), 2.87 (95% CI: 1.46-5.66, p = 0.002), and 3.40 (95% CI: 1.68-6.89, p = 0.001), respectively. The odds of overall response for those who had elevated CTCs compared to those who did not at baseline, day 15, and day 29, were 0.25 (95% CI: 0.073-0.81, p = 0.024), 0.18 (95% CI: 0.04-0.67, p = 0.014), and 0.06 (95% CI: 0.01-0.28, p = 0.001), respectively. There was no apparent prognostic effect comparing the degree of CTC-apoptosis vs. non-apoptosis.

Conclusions: Similar to observations in other intrinsic subgroups, CTCs were detected in a large fraction of TN MBC patients at baseline using CellSearch® assay, and reductions in CTC levels reflected response. In these homogenously prospectively enrolled TN MBC patients, regardless of treatment, CTCs are prognostic at baseline, day 15, and day 29. It does not appear that analysis of CTC-apoptosis is prognostic.

Supported by Susan G. Komen for the Cure, Veridex, LLC, Fashion Footwear Charitable Foundation of New York/QVC Presents Shoes on Sale™ (DFH), Associazione Sandro Pitigliani and by a studentship from FIRC (CP), Triple Negative Breast Cancer Foundation, The AVON Foundation, and The Breast Cancer Research Foundation.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-04-01.

Abstract OT1-3-01: Characterization of circulating tumor cells from subjects with metastatic breast cancer using the CTC-endocrine therapy index: The COMETI-P2-2012.0 trial

Introduction: Approximately 50% of patients with estrogen receptor (ER) positive metastatic breast cancer (MBC) benefit from endocrine therapy (ET). This percentage is even lower after first line ET. Other than absence of ER, there are no validated markers that predict lack of benefit from ET. Prior studies suggest that relative levels of four markers might predict lack of benefit from ET: low ER and BCL2 and high HER2, and Ki67. Elevated circulating tumor cell (CTC) levels are prognostic in patients with MBC. We have recently demonstrated the ability to quantify ER, BCL2, HER2 and Ki67 on CTC using the CellSearch® system, and we have developed an analytically validated CTC-Endocrine Therapy Index (CTC-ETI). We are now conducting a prospective, multi-institutional clinical trial to test whether pretreatment CTC-ETI predicts lack of benefit from ET, and whether serial CTC-ETI measurements can be used to monitor patients with ER positive MBC starting 2nd or later line of ET.

Objectives: To demonstrate that CTC-ETI can be accurately determined in multiple centers across North America and whether high CTC-ETI is associated with rapid progression (within 3 months of starting ET), and finally to refine the current CTC-ETI algorithm.

Secondary objectives: To determine if changes in CTC-ETI during ET are associated with rapid progression, to correlate the status of the biomarkers on baseline CTC with the status of the same biomarkers in primary and/or metastatic tissue collected from the subjects, and to store CTC positive cartridges for future molecular analyses.

Methods: Women with ER positive, HER2 negative, progressive MBC after one or more lines of ET or during or within 12 months of completing adjuvant ET who are initiating a new ET are eligible. Subjects with brain metastases only or those who are progressing on fulvestrant are not eligible. All subjects must provide written informed consent. Patients may be treated with any approved ET for MBC, and may also receive everolimus. Patients may not be on any investigational therapy. Blood draws (approximately 40 ml) are collected at baseline, at 1, 2, and 3 months after starting therapy, and at 12 months or progression. CTC-ETI is performed as previously described.

Statistical Plan: Enrollment of 200 subjects will provide a sufficient number of evaluable subjects and statistical power for evaluation of the primary and secondary objectives. A total of 120 subjects evaluable for clinical validity analyses will be required to obtain the minimum of 51 subjects with rapid progression for evaluation of the clinical validity of the CTC-ETI. Subjects will be considered evaluable for clinical validity if they have successful calculation of a baseline CTC-ETI and progression status within 3 months of starting ET can be ascertained.

Current Status: The first patient was enrolled in May, 2013, and accrual is ongoing.

Sponsored by Veridex, LLC.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-3-01.

Abstract PD6-4: Heterogeneity of expression of estrogen receptor by circulating tumor cells suggests diverse mechanisms of resistance to fulvestrant in metastatic breast cancer patients

Introduction: Fulvestrant is a selective estrogen receptor down-regulator (SERD). Recent studies have shown that the efficacy of fulvestrant is dose-related. However, at the higher dose (500 mg/month) most cancers develop resistance and progress. We previously reported expression of several markers, including estrogen receptor (ER) and BCL-2, on breast cancer circulating tumor cells (CTC) using CellSearch®. We now report pilot data showing inter-patient heterogeneity of these markers on CTC in patients with known ER positive breast cancer whose disease is progressing on fulvestrant.

Methods: We conducted a pilot trial to determine the analytical validity of measuring expression of markers of endocrine sensitivity (ER, BCL-2) or resistance (HER-2, Ki-67) with fluorescent-labeled antibodies using the CellSearch® system. Patients with ER positive metastatic breast cancer (MBC) whose disease was progressing on any type of therapy were eligible after signed informed consent. This report is limited to the subjects who were progressing on fulvestrant. Whole blood (WB) was characterized for CTC counts and each of the four molecular markers using the CXC CellSearch® kit.

Results: Of 50 enrolled patients, seven were progressing on fulvestrant. Two patients had no detectable CTC, while five patients had an average of ≥5 CTC/7.5 mL WB. Results are shown in a table below:

   CTC-ERCTC-BCL-2Patient #Fulvestrant dose (mg/month)Days since last doseN CTC/7.5 mL of WB% of CTC-ER+N CTC/7.5 mL of WB% of CTC-BCL-2+295002880%110%4550028170%170%2250341010%714%850031812%1735%172507728%367%

These exploratory data suggest widely different mechanisms of resistance to fulvestrant in different patients with ER positive MBC. In two of the patients (29, 45) treated with 500 mg/month, both CTC-ER and CTC-BCL-2 expression were absent, suggesting no signaling through the ER pathway. We hypothesize either that fulvestrant was actively down-regulating ER, but the cancers had adopted other growth and survival pathways, or that ER negative, hormone-independent clones had evolved. In the other three cases, ER was clearly present with evidence of signaling, based on BCL-2 expression. Two of these patients (2, 17) were on the lower dose of fulvestrant, now considered to be less effective. However, the third (8) was on the higher dose and yet still had evidence of ER signaling. This observation suggests that some patients may benefit from even higher doses of SERD therapy.

Conclusions: These pilot results suggest heterogeneous biological or pharmacological mechanisms of resistance to SERD therapy. These data suggest that CTC-ER and CTC-BCL-2 expression could serve as pharmacodynamic monitoring tools for dose escalation of fulvestrant or other SERDs. Further molecular analysis might provide biological bases for resistance to fulvestrant.

Supported by Veridex, LLC, Fashion Footwear Charitable Foundation of New York/QVC Presents Shoes on Sale™ (DFH), Associazione Sandro Pitigliani and by a studentship from FIRC (CP).

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD6-4.

Circulating tumour cells: insights into tumour heterogeneity

Tumour heterogeneity is a major barrier to cure breast cancer. It can exist between patients with different intrinsic subtypes of breast cancer or within an individual patient with breast cancer. In the latter case, heterogeneity has been observed between different metastatic sites, between metastatic sites and the original primary tumour, and even within a single tumour at either a metastatic or a primary site. Tumour heterogeneity is a function of two separate, although linked, processes. First, genetic instability is a hallmark of malignancy, and results in 'fixed' genetic changes that are almost certainly carried forward through progression of the cancer over time, with increasingly complex additional genetic changes in new metastases as they arise. The second type of heterogeneity is due to differential but 'plastic' expression of various genes important in the biology and response to various therapies. Together, these processes result in highly variable cancers with differential response, and resistance, to both targeted (e.g. endocrine or anti-human epithelial growth receptor type 2 (HER2) agents) and nontargeted therapies (e.g. chemotherapy). Ideally, tumour heterogeneity would be monitored over time, especially in relation to therapeutic strategies. However, biopsies of metastases require invasive and costly procedures, and biopsies of multiple metastases, or serially over time, are impractical. Circulating tumour cells (CTCs) represent a potential surrogate for tissue-based cancer and therefore might provide the opportunity to monitor serial changes in tumour biology. Recent advances have enabled accurate and reliable quantification and molecular characterization of CTCs with regard to a number of important biomarkers including oestrogen receptor alpha and HER2. Preliminary data have demonstrated that expression of these markers between CTCs in individual patients with metastatic breast cancer reflects the heterogeneity of the underlying tumours. Future studies are designed to determine the clinical utility of these novel technologies in either research or routine clinical settings.

P4-07-16: Development of Circulating Tumor Cell-Endocrine Therapy Index in Metastatic Breast Cancer Patients

Introduction: Only ∼ 50% of patients (pts) with estrogen receptor (ER) positive metastatic breast cancer (MBC) benefit from endocrine therapy (ET). Currently only clinical judgment can be used to identify pts with endocrine-refractory MBC, who are better palliated with chemotherapy. Circulating Tumor Cells (CTC) are reliably enumerated using an automated immunomagnetic system (CellSearch®; Veridex LLC). High CTC levels predict rapid progression in pts with MBC. We have developed a multi-parameter assay, the CTC-Endocrine Therapy Index (CTC-ETI) using CellSearch® that may identify pts with ER positive MBC who are unlikely to benefit from ET and may be better served with chemotherapy. CTC-ETI scores are assigned based on CTC levels coupled with the relative percent and degree of marker positivity on the CTC. We report preliminary results from a pilot single institutional study.

Methods: CellSearch® has 4 fluorescence channels. Three distinguish CTC from WBC (DAPI, anti-cytokeratin, anti-CD45). The 4th “empty” channel was used to measure ER, BCL-2, HER-2, and Ki-67 expression with fluorescent-labeled antibodies. These 4 markers reflect sensitivity (ER, BCL-2) or resistance (HER-2, Ki-67) to ET. Forty ml of blood was drawn into 4 CellSave® tubes from pts with progressive MBC. Whole blood from 4 tubes was pooled and divided into 4 different 7.5 ml aliquots of blood, which were processed and characterized for CTC counts and each of the four molecular markers using the CXC CellSearch® kit.

Results: 21 pts have been accrued to the feasibility study. One patient was ineligible. Five of 20 pts had low CTC counts (&lt;5 CTC/7.5ml whole blood), and are expected to have a relatively favorable prognosis. CTC-ETI was successfully determined in 10 pts (50%): 2 pts had low, while 3 had intermediate, and 5 had high CTC-ETI. Technical difficulties precluded accurate CTC-ETI in the remaining 5 patients. Of note, expression of the biomarkers among CTC in single patients was heterogeneous, suggesting that future iterations of the CTC-ETI will have to consider expression variability. Further exploratory results regarding associations between CTC-ETI and outcomes will be presented.

Conclusions: ER, BCL-2, HER-2, and Ki-67 can be accurately determined on CTC using the 4th channel in the CellSearch® system to calculate CTC-ETI. We predict that lower CTC-ETI scores (low or no CTC, or CTC with high CTC ER and BCL-2 and low CTC HER-2 and Ki-67) could be associated with favorable response to ET. Successful completion of the feasibility study will lead to a prospective trial to determine if high CTC-ETI at baseline predicts resistance and rapid progression on ET in women starting a new endocrine therapy for MBC.

Supported by Veridex, LLC, Fashion Footwear Charitable Foundation of New York/QVC Presents Shoes on Sale ™ (DFH), Associazione Sandro Pitigliani and by a studentship from FIRC (CP).

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-16.

Molten carbonate fuel cells fed with biogas: combating H(2)S

The use of biomass and waste to produce alternative fuels, due to environmental and energy security reasons, is a high-quality solution especially when integrated with high efficiency fuel cell applications. In this article we look into the coupling of an anaerobic digestion process of organic residues to electrochemical conversion to electricity and heat through a molten carbonate fuel cell (MCFC). In particular the pathway of the exceedingly harmful compound hydrogen sulphide (H(2)S) in these phases is analysed. Hydrogen sulphide production in the biogas is strongly interrelated with methane and/or hydrogen yield, as well as with operating conditions like temperature and pH. When present in the produced biogas, this compound has multiple negative effects on the performance and durability of an MCFC. Therefore, there are important issues of integration to be solved. Three general approaches to solve the sulphur problem in the MCFC are possible. The first is to prevent the formation of hydrogen sulphide at the source: favouring conditions that inhibit its production during fermentation. Secondly, to identify the sulphur tolerance levels of the fuel cell components currently in use and develop sulphur-tolerant components that show long-term electrochemical performance and corrosion stability. The third approach is to remove the generated sulphur species to very low levels before the gas enters the fuel cell.

Long-Term Survival in Metastatic Melanoma Patients Treated with Sequential Biochemotherapy: Report of a Phase II Study

The overall survival for patients with metastatic melanoma is very poor, with a median survival of 8.5 months. In this Phase II trial, we assessed the efficacy, safety, and tolerability of a sequential biochemotherapy schedule, using dacarbazine as antiblastic agent and immunomodulant doses of interleukin-2 and interferon-alfa. Thirty-one eligible patients with metastatic melanoma received dacarbazine IV as antiblastic therapy and interluekin-2, plus interferon-alfa SC as sequential immunotherapy, for 6 months. Responding and nonprogressing patients were subsequently maintained on immunotherapy treatment for further 6 months. Twenty-nine patients had an adequate trial, and were assessable for both response and toxicities, with a median follow-up of 49 months. The overall response rate was 52 percent (3 CR and 12 PR), SD was 8 (27 percent) and PD were achieved in 6 patients (21 percent). The median survival duration of responders was 28 months, significantly longer (p < 0.001) than the 16 months of nonresponders. Therapy was well tolerated and produced a significant improvement in progressive-free survival. Further studies, thus, are recommended for larger groups of patients not only to confirm these results, but also to apply this biochemotherapy regimen as adjuvant postsurgical treatment in early stages of malignant melanoma.

Oxaliplatin, 5-fluorouracil/leucovorin and epirubicin as first-line treatment in advanced gastric carcinoma: a phase II study

The association between oxaliplatin and 5-fluorouracil (5-FU) has been extensively reported to improve prognosis of gastric cancer patients. The present study is aimed at evaluating response rate and the toxicity profile of the association with oxaliplatin, 5-FU/lecovorin and epirubicin in gastric cancer patients with locally advanced or metastatic disease. Thirty-six patients have been enrolled and 35 evaluated. The treatment schedule was oxaliplatin (100 mg m(-2)), 5-FU (400 mg m(-2)), leucovorin (40 mg m(-2)) and epirubicin (60 mg m(-2)) intravenously. administered every 3 weeks for 6 months, for a total of 185 therapy cycles . Response rate and toxicity were assessed according to the international WHO criteria. Every patient received a mean of 5.3 therapy cycles in a day-hospital setting. Sixteen of 35 patients (46%) showed an objective response, two complete response and 14 partial response. Median time to progression was 33 weeks with an overall median survival of 49 weeks. During the study, anaemia grade 3 and neutropenia grade 3 were observed in 9 and 11% of patients respectively. A grade 3 periferic sensorial neuropathy was observed in 6% of patients. No life threatening or cardiac toxicity was recorded. The regimen used showed anticancer activity against gastric carcinoma, a tolerable toxicity profile and excellent patient compliance.

VanA-type enterococci from humans, animals, and food: species distribution, population structure, Tn1546 typing and location, and virulence determinants

VanA-type human (n=69), animal (n=49), and food (n=36) glycopeptide-resistant enterococci (GRE) from different geographic areas were investigated to study their possible reservoirs and transmission routes. Pulsed-field gel electrophoresis (PFGE) revealed two small genetically related clusters, M39 (n=4) and M49 (n=13), representing Enterococcus faecium isolates from animal and human feces and from clinical and fecal human samples. Multilocus sequence typing showed that both belonged to the epidemic lineage of CC17. purK allele analysis of 28 selected isolates revealed that type 1 was prevalent in human strains (8/11) and types 6 and 3 (14/15) were prevalent in poultry (animals and meat). One hundred and five of the 154 VanA GRE isolates, encompassing different species, origins, and PFGE types, were examined for Tn1546 type and location (plasmid or chromosome) and the incidence of virulence determinants. Hybridization of S1- and I-CeuI-digested total DNA revealed a plasmid location in 98% of the isolates. Human intestinal and animal E. faecium isolates bore large (>150 kb) vanA plasmids. Results of PCR-restriction fragment length polymorphism and sequencing showed the presence of prototype Tn1546 in 80% of strains and the G-to-T mutation at position 8234 in three human intestinal and two pork E. faecium isolates. There were no significant associations (P>0.5) between Tn1546 type and GRE source or enterococcal species. Virulence determinants were detected in all reservoirs but were significantly more frequent (P<0.02) among clinical strains. Multiple determinants were found in clinical and meat Enterococcus faecalis isolates. The presence of indistinguishable vanA elements (mostly plasmid borne) and virulence determinants in different species and PFGE-diverse populations in the presence of host-specific purK housekeeping genes suggested that all GRE might be potential reservoirs of resistance determinants and virulence traits transferable to human-adapted clusters.

Risk of melanoma following adulthood cancer: A case-control study

Melanoma is a severe skin cancer related to sun exposure. Whether this malignancy is linked to exposure to ionising radiation during adulthood is still controversial. This case-control study examined the risk of melanoma following treatment for an adulthood first malignant neoplasm (FMN). Cases were patients who presented with cutaneous melanoma after a first cancer in adulthood. Controls (3 per case) were patients free of melanoma, matched for age, duration of follow-up since the FMN, type of FMN, and followed in the same institution. A total of 57 cases and 171 controls were included. In the final multivariate analysis, no risk of melanoma was associated with radiotherapy (odds ratio (OR) for 1 Gy = 1.01, 95% confidence interval (95%CI) 0.96-1.07) nor hormonotherapy, whereas chemotherapy use (OR = 2.3, 95%CI 0.93-5.6) and having a history of familial cancer (OR = 2.8, 95%CI 1.3-5.9) exhibited a nearly significant risk. In conclusion, unlike the evidence for risk of exposure to ionising radiation during childhood, we did not substantiate a risk for association of melanoma with exposure to ionising radiation during adulthood. The risk associated with chemotherapy should justify the implementation of skin surveillance for early detection of melanoma in these patients.

Smoking cessation rates 4 years after treatment by nicotine gum and acupuncture

BACKGROUND

This study was done to estimate the smoking cessation rates 4 years after treatment with acupuncture and nicotine gum.

METHODS

Participants were randomized in a 2 x 2 factorial design to four groups: double active treatments (nicotine gum and acupuncture), double placebo, and the combination of one active treatment and placebo.

RESULTS

The success rates were quite similar in the four groups at the different points of follow-up. They sharply decreased between 1 month (around 23%) and 1 year (around 10%). The decrease slowed down thereafter to around 6% at 4 years.

CONCLUSIONS

Results from our study suggest that the two treatments did not offer any long-term improvement over placebo. Additional investigations are necessary to estimate the magnitude of their long-term success rate.

Effects of CYP2D6 activity and tobacco on larynx cancer risk

The genetically determined capacity of the cytochrome P450 CYP2D6 is suspected to be involved in the activation of tobacco carcinogens. From a multicentric case-control study carried out to analyze the interaction between host and environmental factors on tobacco-related cancers, we reported recently that the effect of tobacco on lung cancer risk rose with increasing CYP2D6 activity, and the effect of CYP2D6 activity rose with increasing tobacco consumption. The aim of the present report was to investigate whether results on lung cancer could be observed for larynx cancer, from a study on 140 cases and 157 controls. A weak interaction between increasing levels of both CYP2D6 activity and average daily consumption of tobacco was found (P = 0.12). The only significant interaction between these two factors was observed when CYP2D6 activity was considered with the two conventional phenotypes (P < 0.05). A dose-response effect of tobacco on larynx cancer risk was found only among one-third of the smokers with the highest level of CYP2D6 activity, and CYP2D6 was a risk factor only among heavy smokers. The highest risk for larynx cancer was then observed among smokers having both the highest levels of CYP2D6 activity and daily consumption of tobacco. The interaction between CYP2D6 activity and tobacco was weaker for larynx cancer than that reported previously for lung cancer. However, the similarities in the results found for these two cancers, i.e., a greater effect of tobacco among smokers with the highest CYP2D6 activity, reinforce the hypothesis that this activity could modify the effect of tobacco on cancer risk.

[In vitro stimulation by ellipticine derivatives of DNA cleavage induced by DNA topoisomerase II: a structure-activity relationship]

Ellipticines are intercalating planar polycyclic aromatic molecules that display antitumor activity. The cytotoxicity of these compounds is related to the presence of an hydroxy group at position 9 of the pyridocarbazole ring system and to their interaction with DNA topoisomerase II. The ability of 13 ellipticine derivatives to stabilize the topoisomerase II-DNA covalent complex in vitro is reported. The following observations emerge from our structure-activity relationship study: i) the hydroxy group at position 9 is essential for stabilizing the covalent complex, ii) the replacement of the methyl group at position 5 by an ethyl group (EPC) enhances the complex stabilization. The interaction of EPC and three other ellipticine analogues with DNA shows that the covalent complexes which are most stable have the lowest drug-DNA binding constants. In addition our study suggests that ellipticines induce covalent complex stabilization by a cooperative mechanism. A model is proposed to explain this stabilization by ellipticines. This study supports the idea that topoisomerase II is the primary target involved in the mechanisms of action of ellipticines.

The localization of topoisomerase II cleavage sites on DNA in the presence of antitumor drugs

Type II topoisomerase are enzymes that break and religate DNA phosphodiester bonds while crossing over DNA strands and altering DNA topology. They also are structural proteins that play a role in the spatial organization of chromatin and are involved in several crucial biological functions, such as DNA replication and transcription, chromosome segregation and recombination. Many drugs interfere with type II topoisomerases and can be assigned to two groups. Coumarin derivatives and synthetic quinolones act at the level of ATP binding or hydrolysis and are used for controlling bacterial infections. Drugs belonging to the second group produce DNA lesions by trapping a "cleavable complex" consisting of the normal transient topoisomerase II-DNA reaction intermediate in which the enzyme and the DNA are joined by two covalent bonds. There are four main categories of antitumour drugs that form cleavable complexes in eukaryotes: acridines, anthracyclines, ellipticines and epipodophyllotoxins. These drugs are cytotoxic and many--but not all--are endowed with antitumoral properties. The mechanisms of this pharmacological activity are not understood. Topoisomerase II-induced DNA breaks generated from cleavable complexes display different levels of cytotoxicity depending on their localization on DNA. The primary structure of DNA is not the only parameter that determines this localization. The spatial organization of the enzyme-DNA complex and both the topology and the structure of the underlying chromatin fiber constitute additional critical factors. It, therefore, may be unrealistic to expect that the actual pharmacological potency of antitumor drugs that act on type II topoisomerases can be accurately predicted solely on the basis of simple in vitro test tube experiments carried out using pure enzymes and naked DNA.

A carboline derivative as a novel mammalian DNA topoisomerase II targeting agent

The DNA intercalating, ellipticine analog drug, 5,11-dimethyl-5H-indol[2,3-b]quinoline, is able to stabilize in vitro the topoisomerase II-DNA cleavable complex and to induce DNA breaks in BPV I episome in rat fibroblasts. Cytotoxicity studies with DC3F cells resistant to ellipticine strongly suggest that topoisomerase II is a cellular target involved in the mechanism of cytotoxic action of this carboline derivative.

Does cruciform DNA provide a recognition signal for DNA-topoisomerase II?

Topoisomerase II displays higher affinity for supercoiled DNA compared to the same relaxed DNA. Moreover, cruciform structures are formed in topologically constrained DNA. Here we report that, using S1 nuclease experiments on supercoiled DNA, hairpin structures are located close to numerous topoisomerase II cleavage sites on the BPV I genome. Therefore, DNA secondary structure may play a role in the recognition mechanism of DNA by topoisomerase II.

[Bipolar disorder: clinical trials with fluoxetine]

Sixty patients (39 females and 21 males) aged between 20 and 65 (average 48.5) with bipolar disorder in the depressive phase, according to the DSM III-R diagnostic criteria, were treated with fluoxetine (20-60 mg/die) for 8 weeks. Evaluation of therapeutical efficacy was performed at 0 time and after 14, 28, 42, and 56 days, using the following psychometric tests; HAM-D, SCL-90, CGI. At the end of treatment 42 patients (70%) showed a reduction of the HAM-D score over 50%. Clinical results suggest that fluoxetine is affective in bipolar disorder. Tolerability was judged good and very good in 76% of patients. Side effects were very mild and in any case of rapid regression.

Stimulation of topoisomerase II-mediated DNA cleavage by ellipticine derivatives: structure-activity relationship

Ellipticines are aromatic compounds that intercalate between DNA base pairs and display significant antitumor activity. The cytotoxicity of these compounds is mediated by DNA topoisomerase II, and the presence of a hydroxy group at position 9 of the pyridocarbazole ring system of ellipticines has been found to be essential for high levels of cytotoxicity. The ability of 13 ellipticine derivatives to stabilize the topoisomerase II-DNA covalent complex in vitro was studied, and the data obtained with five pairs of hydroxylated and nonhydroxylated analogues indicate that the hydroxy group at position 9 plays a crucial role in the stabilization of the complex. The influence, upon the complex stabilization, of various substituents at positions 1, 2, 5, and 6 of the pyridocarbazole ring system was investigated. The interaction with DNA of four ellipticine derivatives was studied in the topoisomerase II standard medium. Results suggest that the degree of unwinding might be a determinant of topoisomerase II-DNA-drug complex stability. In addition, the 5-ethyl derivative was observed to induce covalent complex stabilization by a cooperative mechanism.

Sequence requirements for mammalian topoisomerase II mediated DNA cleavage stimulated by an ellipticine derivative

Various antitumor drugs stabilize DNA topoisomerase II-DNA transient covalent complexes. The complexes distribution along pBR322 DNA was shown previously to depend upon the nature of the drug (Tewey et al. (1984) Science 226, 466-468). The position in pBR322 of DNA cleavage by calf DNA topoisomerase II for 115 such sites stabilized by an ellipticine derivative and the relative frequency of cleavage at most of these sites were determined. The nucleotide sequence surrounding the 25 strongest sites was analyzed and the following ellipticine specific consensus sequence was deduced: 5'-ANCNT(A/G)T.NN(G/C)N(A/G)-3' where cleavage occurs at the indicated mark. A thymine is always present at the 3' end of at least one strand of the strong cleavage sites, and the dinucleotide AT or GT at the 3' end of the break plays a major role in the complex stabilisation. The predictive value of cleavage of the consensus was tested for two regions of SV40 DNA and cleavage was indeed detected at the majority of the sites matching the consensus. Some complexes stabilized by ellipticine are resistant to salt dissociation and this property seems to be correlated with the presence of symmetrical sequences in the cleavage site with a center of symmetry staggered relatively to the center of symmetry of cleavage.

[Efficacy and tolerance of aniracetam in elderly patients with primary or secondary mental deterioration]

The study was carried out on 60 patients (mean age 69.9 +/- 10.3 years) suffering from slight-moderate brain pathology primary or secondary to vascular forms. Patients were treated with 1500 mg/day per os of Aniracetam or placebo. Drug efficiency evaluation was performed utilizing the following psychometric tests: Blessed Scale, figures repetition test, Benton test, Corsi test, Rey test, Pieron test, phrases construction test, verbal fluency test. They were carried out during basal visit after two and four month treatment. In Aniracetam treated group the score showed a significant improving during the first and second control. In placebo treated group no change statistically considerable happened in any test. Aniracetam has proved to be a useful drug in slight-moderate brain decay treatment of the elderly.

[Evaluation of the efficacy and tolerability of fluoxetine in major depression, Multicenter clinical study]

In an Italian multicenter study, 296 patients (115 males, 181 females) affected with major depression diagnosed according to the criteria of the DSM III-R, were treated for 8 weeks with 20 mg/die fluoxetine (Fluoxeren-Menarini s.r.l.). At the end of the therapy the mean scores on the Hamilton Depression Scale had improved considerably, going down from 27.42 to 10.05. 69.6% of the patients had improved by at least in the 50% in the HAM-D scores (responders). At the CGI the overall improvement was evaluated with a mean score of 2.05 (marked improvement), while the patients assessed themselves at the end of treatment as being from "improved" to "greatly improved". No significant differences in efficacy were found to depend on age, type of depression or response to previous treatment, though younger patients (18-40 years), and those with single or recurring episodes, with atypical depression and good response to other antidepressants, showed a more marked improvement. The tolerability of the drug was found to be good. The laboratory tests, ECG and body weight stayed within normal limits.