Journal of Translational Medicine - Latest Articles

Low temperature of radiofrequency ablation at the target sites can facilitate rapid progression of residual hepatic VX2 carcinoma

Shan Ke — 2010-07-29T00:00:00Z

Background: Rapid progression of residual tumor after radiofrequency ablation (RFA) of hepatocellular carcinoma has been observed increasingly. However, its underlying mechanisms remain to be clarified. The present study was designed to determine whether low temperature of RFA at the target sites facilitates rapid progression of residual hepatic VX2 carcinoma and to clarify the possible underlying mechanisms. Methods: The residual VX2 hepatoma model in rabbits was established by using RFA at 55, 70 and 85 degrees C. Rabbits that were implanted with VX2 hepatoma but did not receive RFA acted as a control group. The relationship between rapid progression of residual hepatic VX2 carcinoma and low temperature of RFA at the target sites was carefully evaluated. A number of potential contributing molecular factors, such as proliferating cell nuclear antigen (PCNA), matrix metalloproteinase 9 (MMP-9), vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and Interleukin-6 (IL-6) were measured. Results: The focal tumor volume and lung metastases of RFA-treated rabbits increased significantly compared with the control group (P<0.05), and the greatest changes were seen in the 55 degrees C group (P<0.05). Expression of PCNA, MMP-9, VEGF, HGF and IL-6 in tumor tissues increased significantly in the RFA-treated groups compared with the control group, and of the increases were greatest in the 55 degrees C group (P<0.05). These results were consistent with gross pathological observation. Tumor re-inoculation experiments confirmed that low temperature of RFA at the target sites facilitated rapid progression of residual hepatic VX2 carcinoma. Conclusions: Insufficient RFA that is caused by low temperature at the target sites could be an important cause of rapid progression of residual hepatic VX2 carcinoma. Residual hepatic VX2 carcinoma could facilitate its rapid progression through inducing overexpression of several molecular factors, such as PCNA, MMP-9, VEGF, HGF and IL-6.

Rational design of HIV vaccine and microbicides: report of the EUROPRISE annual conference

Britta Wahren — 2010-07-26T00:00:00Z

EUROPRISE is a Network of Excellence sponsored from 2007 to 2011 by the European Commission under the 6th Framework Program. The Network encompasses a wide portfolio of activities ranging from an integrated research program in the field of HIV vaccines and microbicides to training, dissemination and advocacy. The research program covers the whole pipeline of vaccine and microbicide development from discovery to early clinical trials. The Network is composed of 58 partners representing more than 65 institutions from 13 European countries; it also includes three major pharmaceutical companies (GlaxoSmithKline, Novartis and Sanofi-Pasteur) involved in HIV microbicide and vaccine research. The Network displays a dedicated and informative web page: www.europrise.org. Finally, a distinguishing trait of EUROPRISE is its PhD School of students from across Europe, a unique example in the world of science aimed at spreading excellence through training.EUROPRISE held its second annual conference in Budapest on November, 2009. The conference had 143 participants and their presentations covered aspects of vaccine and microbicide research, development and discovery. Since training is a major task of the Network, the students of the EUROPRISE PhD program summarized certain presentations and their view of the conference in this paper.

First-line chemoimmunotherapy in metastatic breast carcinoma: combination of paclitaxel and IMP321 (LAG-3Ig) enhances immune responses and antitumor activity

Chrystelle Brignone — 2010-07-23T00:00:00Z

Background: IMP321 is a recombinant soluble LAG-3Ig fusion protein that binds to MHC class II with high avidity and mediates APC and then antigen-experienced memory CD8+ T cell activation. We report clinical and biological results of a phase I/II in patients with metastatic breast carcinoma (MBC) receiving first-line paclitaxel weekly, 3 weeks out of 4. Methods: MBC patients were administered one dose of IMP321 s.c. every two weeks for a total of 24 weeks (12 injections). The repeated single doses were administered the day after chemotherapy at D2 and D16 of the 28-day cycles of paclitaxel (80 mg/m2 at D1, D8 and D15, for 6 cycles). Blood samples were taken 13 days after the sixth and the twelfth IMP321 injections to determine sustained APC, NK and memory CD8 T cell responses. Results: Thirty MBC patients received IMP321 in three cohorts (doses: 0.25, 1.25 and 6.25 mg). IMP321 induced both a sustained increase in the number and activation of APC (monocytes and dendritic cells) and an increase in the percentage of NK and long-lived cytotoxic effector-memory CD8 T cells. Clinical benefit was observed for 90 % of patients with only 3 progressors at 6 months. Also, the objective tumor response rate of 50 % compared favorably to the 25 % rate reported in the historical control group. Conclusions: The absence of toxicity and the demonstration of activity strongly support the future development of this agent for clinical use in combined first-line regimens.Trial registration: ClinicalTrials.gov NCT00349934

Copy number and gene expression differences between African American and Caucasian American prostate cancer

Amy Rose — 2010-07-22T00:00:00Z

Background: The goal of our study was to investigate the molecular underpinnings associated with the relatively aggressive clinical behavior of prostate cancer (PCa) in African American (AA) compared to Caucasian American (CA) patients using a genome-wide approach. Methods: AA and CA patients treated with radical prostatectomy (RP) were frequency matched for age at RP, Gleason grade, and tumor stage. Array-CGH (BAC SpectralChip2600) was used to identify genomic regions with significantly different DNA copy number between the groups. Gene expression profiling of the same set of tumors was also evaluated using Affymetrix HG-U133 Plus 2.0 arrays. Concordance between copy number alteration and gene expression was examined. A second aCGH analysis was performed in a larger validation cohort using an oligo-based platform (Agilent 244K). Results: BAC-based array identified 27 chromosomal regions with significantly different copy number changes between the AA and CA tumors in the first cohort (Fisher's exact test, P<0.05). Copy number alterations in these 27 regions were also significantly associated with gene expression changes. aCGH performed in a larger, independent cohort of AA and CA tumors validated 4 of the 27 (15%) most significantly altered regions from the initial analysis (3q26, 5p15-p14, 14q32, and 16p11). Functional annotation of overlapping genes within the 4 validated regions of AA/CA DNA copy number changes revealed significant enrichment of genes related to immune response. Conclusions: Our data reveal molecular alterations at the level of gene expression and DNA copy number that are specific to African American and Caucasian prostate cancer and may be related to underlying differences in immune response.

Evaluation of normalization methods for two-channel microRNA microarrays

Yingdong Zhao — 2010-07-21T00:00:00Z

Background: MiR arrays distinguish themselves from gene expression arrays by their more limited number of probes, and the shorter and less flexible sequence in probe design. Robust data processing and analysis methods tailored to the unique characteristics of miR arrays are greatly needed. Assumptions underlying commonly used normalization methods for gene expression microarrays containing tens of thousands or more probes may not hold for miR microarrays. Findings from previous studies have sometimes been inconclusive or contradictory. Further studies to determine optimal normalization methods for miR microarrays are needed. Methods: We evaluated many different normalization methods for data generated with a custom-made two channel miR microarray using two data sets that have technical replicates from several different cell lines. The impact of each normalization method was examined on both within miR error variance (between replicate arrays) and between miR variance to determine which normalization methods minimized differences between replicate samples while preserving differences between biologically distinct miRs. Results: Lowess normalization generally did not perform as well as the other methods, and quantile normalization based on an invariant set showed the best performance in manyost cases unless restricted to a very small invariant set. Global median and global mean methods performed reasonably well in both data sets and have the advantage of computational simplicity. Conclusions: Researchers need to consider carefully which assumptions underlying the different normalization methods appear most reasonable for their experimental setting and possibly consider more than one normalization approach to determine the sensitivity of their results to normalization method used.

Effective knowledge management in translational medicine

Sandor Szalma — 2010-07-19T00:00:00Z

Background: The growing consensus that most valuable data source for biomedical discoveries is derived from human samples is clearly reflected in the growing number of translational medicine and translational sciences departments across pharma as well as academic and government supported initiatives such as Clinical and Translational Science Awards (CTSA) in the US and the Seventh Framework Programme (FP7) of EU with emphasis on translating research for human health. Methods: The pharmaceutical companies of Johnson and Johnson have established translational and biomarker departments and implemented an effective knowledge management framework including building a data warehouse and the associated data mining applications. The implemented resource is built from open source systems such as i2b2 and GenePattern. Results: The system has been deployed across multiple therapeutic areas within the pharmaceutical companies of Johnson and Johnsons and being used actively to integrate and mine internal and public data to support drug discovery and development decisions such as indication selection and trial design in a translational medicine setting. Our results show that the established system allows scientist to quickly re-validate hypotheses or generate new ones with the use of an intuitive graphical interface. Conclusions: The implemented resource can serve as the basis of precompetitive sharing and mining of studies involving samples from human subjects thus enhancing our understanding of human biology and pathophysiology and ultimately leading to more effective treatment of diseases which represent unmet medical needs.

Incidence of the V600K mutation among melanoma patients with BRAF mutations, and potential therapeutic response to the specific BRAF inhibitor PLX4032

Jill Rubinstein — 2010-07-14T00:00:00Z

Activating mutations in BRAF kinase are common in melanomas. Clinical trials with PLX4032, the BRAF-mutant inhibitor, show promising preliminary results in patients selected for the presence of V600E mutation. However, activating V600K mutation is the other most common mutation, yet patients with this variant are currently excluded from the PLX4032 trials. Here we present evidence that a patient bearing the BRAF V600K mutation responded remarkably to PLX4032, suggesting that clinical trials should include all patients with activating BRAF V600E/K mutations.

Mass spectrometry-based analysis of therapy-related changes in serum proteome patterns of patients with early-stage breast cancer

Monika Pietrowska — 2010-07-11T00:00:00Z

Background: The proteomics approach termed proteome pattern analysis has been shown previously to have potential in the detection and classification of breast cancer. Here we aimed to identify changes in serum proteome patterns related to therapy of breast cancer patients. Methods: Blood samples were collected before the start of therapy, after the surgical resection of tumors and one year after the end of therapy in a group of 70 patients diagnosed at early stages of the disease. Patients were treated with surgery either independently (26) or in combination with neoadjuvant chemotherapy (5) or adjuvant radio/chemotherapy (39). The low-molecular-weight fraction of serum proteome was examined using MALDI-ToF mass spectrometry, and then changes in intensities of peptide ions registered in a mass range between 2,000 and 14,000 Da were identified and correlated with clinical data. Results: We found that surgical resection of tumors did not have an immediate effect on the mass profiles of the serum proteome. On the other hand, significant long-term effects were observed in serum proteome patterns one year after the end of basic treatment (we found that about 20 peptides exhibited significant changes in their abundances). Moreover, the significant differences were found primarily in the subgroup of patients treated with adjuvant therapy, but not in the subgroup subjected only to surgery. This suggests that the observed changes reflect overall responses of the patients to the toxic effects of adjuvant radio/chemotherapy. In line with this hypothesis we detected two serum peptides (registered m/z values 2,184 and 5,403 Da) whose changes correlated significantly with the type of treatment employed (their abundances decreased after adjuvant therapy, but increased in patients treated only with surgery). On the other hand, no significant correlation was found between changes in the abundance of any spectral component or clinical features of patients, including staging and grading of tumors. Conclusions: The study establishes a high potential of MALDI-ToF-based analyses for the detection of dynamic changes in the serum proteome related to therapy of breast cancer patients, which revealed the potential applicability of serum proteome patterns analyses in monitoring the toxicity of therapy.

The status of clinical trials: Cause for concern

Robert Nussenblatt — 2010-07-07T00:00:00Z

Background: Americans see clinical research as important, with over 15 million American residents participating in NIH-sponsored studies in 2008 and growing yearly. Methods: Documents reporting NIH supported Clinical Research projects were reviewed. Results: When compared with other studies, the number of interventional Phase III and Phase IV trials have decreased from 20% to 4.4% from 1994-2008. Conclusions: This finding most likely has occurred for several reasons. One reason is that the physician lacks an infrastructure for designing and carrying out trials. This lack is because of an absence of a coordinated effort to train clinical trialists. It is clear that the Nation needs a more purposeful approach to developing and maintaining the infrastructure for designing and conducting clinical trials. Building it de novo trial by trial is profoundly inefficient, to say nothing about time consuming and error prone.

Functional polymorphisms in genes of the Angiotensin and Serotonin systems and risk of hypertrophic cardiomyopathy: AT1R as a potential modifier.

Eliecer Coto — 2010-07-01T00:00:00Z

Background: Angiotensin and serotonin have been identified as inducers of cardiac hypertrophy. DNA polymorphisms at the genes encoding components of the angiotensin and serotonin systems have been associated with the risk of developing cardiovascular diseases, including left ventricular hypertrophy (LVH). Methods: We genotyped five polymorphisms of the AGT, ACE, AT1R, 5-HT2A, and 5-HTT genes in 245 patients with Hypertrophic Cardiomyopathy (HCM; 205 without an identified sarcomeric gene mutation), in 145 patients with LVH secondary to hypertension, and 300 healthy controls. Results: We found a significantly higher frequency of AT1R 1166 C carriers (CC+AC) among the HCM patients without sarcomeric mutations compared to controls (p = 0.015; OR = 1.56; 95%CI = 1.09-2.23). The AT1R 1166 C was also more frequent among patients who had at least one affected relative, compared to sporadic cases. This allele was also associated with higher left ventricular wall thickness in both, HCM patients with and without sarcomeric mutations. Conclusions: The 1166 C AT1R allele could be a risk factor for cardiac hypertrophy in patients without sarcomeric mutations. Other variants at the AGT, ACE, 5-HT2A and 5-HTT did not contribute to the risk of cardiac hypertrophy.