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Latest Articles on Gene Therapy

Overview of latest articles and publications on gene therapy in PubMed, including Human Gene Therapy, Journal of Molecular Medicine and Journal of Gene Medicine. PubMed is a service of the US National Library of Medicine that includes over 18 million citations from MEDLINE and other life science journals.

  • Integrative radiogenomic analysis for multicentric radiophenotype in glioblastoma.
    Kong DS, Kim J, Lee IH, et al. Integrative radiogenomic analysis for multicentric radiophenotype in glioblastoma. [JOURNAL ARTICLE]Oncotarget 2016 Feb 1.We postulated that multicentric glioblastoma (GBM) represents more invasiveness form than solitary GBM and has their own genomic characteristics. From May 2004 to June 2010 we retrospectively identified 51 treatment-naïve GBM patients with available clinical information from the Samsung Medical Center data registry. Multicentricity of the tumor was defined as the presence of multiple foci on the T1 contrast enhancement of MR images or having high signal for multiple lesions without contiguity of each other on the FLAIR image. Kaplan-Meier survival analysis demonstrated that multicentric GBM had worse prognosis than solitary GBM (median, 16.03 vs. 20.57 months, p < 0.05). Copy number variation (CNV) analysis revealed there was an increase in 11 regions, and a decrease in 17 regions, in the multicentric GBM. Gene expression profiling identified 738 genes to be increased and 623 genes to be decreased in the multicentric radiophenotype (p < 0.001). Integration of the CNV and expression datasets identified twelve representative genes: CPM, LANCL2, LAMP1, GAS6, DCUN1D2, CDK4, AGAP2, TSPAN33, PDLIM1, CLDN12, and GTPBP10 having high correlation across CNV, gene expression and patient outcome. Network and enrichment analyses showed that the multicentric tumor had elevated fibrotic signaling pathways compared with a more proliferative and mitogenic signal in the solitary tumors. Noninvasive radiological imaging together with integrative radiogenomic analysis can provide an important tool in helping to advance personalized therapy for the more clinically aggressive subset of GBM.

  • Estrogen receptor beta as a prognostic factor in breast cancer patients: A systematic review and meta-analysis.
    Tan W, Li Q, Chen K, et al. Estrogen receptor beta as a prognostic factor in breast cancer patients: A systematic review and meta-analysis. [JOURNAL ARTICLE]Oncotarget 2016 Feb 6.The prognostic role of estrogen receptor beta (ERβ) in early-stage breast cancer is unclear. We performed a systematic review and meta-analysis to evaluate the prognostic value of ERβ in early-stage breast cancer patients.We searched Medline, Embase, and the Web of Science for studies published between 1990 and 2015 that assessed ERβ status in breast cancer patients. A total of 25 studies comprising 9919 patients fitting our inclusion and exclusion criteria were included. The hazard ratios of ERβ status were extracted for diseases free survival (DFS)/ ) and overall survival (OS). Random or fixed-effects models were used when appropriate, and between-study heterogeneity was assessed.In the 20 studies that assessed ERβ status using immunohistochemical (IHC) methods, we observed significantly improved DFS in patients positive for ERβ-1 (HR=0.56, 95%CI 0.40-0.78, P=0.0007) and ERβ-2 (HR=0.67, 95%CI 0.45-1.00, P=0.05). Improved OS was associated with a positive status for pan-ERβ (HR=0.60, 95%CI 0.45-0.80, P=0.0004) and ERβ-2 (HR=0.44, 95%CI 0.31-0.62, P<0.0001). In ERα-positive patients, ERβ positivity was not associated with DFS (HR=0.77, 95%CI 0.46-1.27, P=0.31) or OS (HR=0.64, 95%CI 0.37-1.11, P=0.11). In contrast, ERβ expression was significantly associated with increased DFS (HR=0.37, 95%CI 0.14-0.93, P=0.03) or OS (HR=0.44, 95%CI 0.30-0.65, P<0.0001) in ERα-negative patients. We did not observe an association between ERβ mRNA levels and DFS and OS.In this study, we showed that IHC ERβ status, rather than mRNA levels, is a prognostic factor that is associated with DFS and OS in breast cancer patients. The prognostic value of ERβ may be higher in ERα-negative patients than in ERα-positive patients.

  • The next generation of metastatic melanoma: Uncovering the genetic variants for anti-BRAF therapy response.
    Pinto R, De Summa S, Strippoli S, et al. The next generation of metastatic melanoma: Uncovering the genetic variants for anti-BRAF therapy response. [JOURNAL ARTICLE]Oncotarget 2016 Feb 3.Metastatic melanoma (MM) is a highly aggressive cancer with a median overall survival of 6-9 months, notwithstanding the numerous efforts in development of new therapeutic approaches. To this aim we tested the clinical applicability of the Ion Torrent Personal Genome Machine to simultaneously screen MM patients in order to individuate new or already known SNPs and mutations able to predict the duration of response to BRAF inhibitors. An Ampliseq Custom Panel, including 11 crucial full length genes involved in melanoma carcinogenesis and therapy response pathways, was created and used to analyze 25 MM patients. We reported BRAFV600 and NRASQ61 mutations in 68% and 24% of samples, respectively. Moreover, we more frequently identified the following alterations related to BRAF status: PIK3CAI391M (44%) and KITD737N (36%) mutations, CTLA4T17A (52%), MC1RV60L (32%) and MITFS473A (60%) polymorphisms. Considering the progression free survival (PFS), statistical analyses showed that BRAFV600 patients without any of these more frequent alterations had a higher median PFS. Protein structure changes seem to be due to these variants by in silico analysis. In conclusion, a Next-Generation Sequencing approach with custom panel may provide new information to evaluate tumor-specific therapeutic susceptibility and individual prognosis to improve the care of MM patients.

  • Novel SLC19A3 Promoter Deletion and Allelic Silencing in Biotin-Thiamine-Responsive Basal Ganglia Encephalopathy.
    Flønes I, Sztromwasser P, Haugarvoll K, et al. Novel SLC19A3 Promoter Deletion and Allelic Silencing in Biotin-Thiamine-Responsive Basal Ganglia Encephalopathy. [Journal Article]PLoS One 2016; 11(2):e0149055.Biotin-thiamine responsive basal ganglia disease is a severe, but potentially treatable disorder caused by mutations in the SLC19A3 gene. Although the disease is inherited in an autosomal recessive manner, patients with typical phenotypes carrying single heterozygous mutations have been reported. This makes the diagnosis uncertain and may delay treatment.In two siblings with early-onset encephalopathy dystonia and epilepsy, whole-exome sequencing revealed a novel single heterozygous SLC19A3 mutation (c.337T>C). Although Sanger-sequencing and copy-number analysis revealed no other aberrations, RNA-sequencing in brain tissue suggested the second allele was silenced. Whole-genome sequencing resolved the genetic defect by revealing a novel 45,049 bp deletion in the 5'-UTR region of the gene abolishing the promoter. High dose thiamine and biotin therapy was started in the surviving sibling who remains stable. In another patient two novel compound heterozygous SLC19A3 mutations were found. He improved substantially on thiamine and biotin therapy.We show that large genomic deletions occur in the regulatory region of SLC19A3 and should be considered in genetic testing. Moreover, our study highlights the power of whole-genome sequencing as a diagnostic tool for rare genetic disorders across a wide spectrum of mutations including non-coding large genomic rearrangements.

  • Predicting the risk of recurrence before the start of antithyroid drug therapy in patients with Graves' hyperthyroidism.
    Vos XG, Endert E, Zwinderman K, et al. Predicting the risk of recurrence before the start of antithyroid drug therapy in patients with Graves' hyperthyroidism. [JOURNAL ARTICLE]J Clin Endocrinol Metab 2016 Feb 10.:jc20153644.Treatment options of Graves' hyperthyroidism should be tailored to the needs ofindividual patients, taken into account recurrence risk, co-morbidities and personal preferences.To construct a prediction model to calculate recurrence risk after a course of antithyroid drugs, based on clinical and genetic parameters prior to the start of treatment. Design, Setting, and Participants Consecutive, untreated patients with a first episode of Graves' hyperthyroidism were included in a prospective, multicenter, observational study. Before starting antithyroid drugs, clinical parameters and blood samples were collected. Antithyroid drugs were withdrawn after one year, and patients were followed for a further two years. Main Outcome Measures Clinical and genetic markers that are independently associated with recurrent hyperthyroidism, and a multimarker prediction model for recurrence.37% of 178 patients had recurrent Graves' hyperthyroidism within two years after antithyroid drugs withdrawal. In Cox regression, lower age, higher serum fT4, higher serum TBII, larger goiter sizes at diagnosis, PTPN22 C/T polymorphism, and HLA subtypes DQB1*02, DQA1*05, and DRB1*03 were independent predictors for recurrence. Two simplified predictive models were constructed based on hazard ratios of the multivariate model, called the GREAT (Graves' Recurrent Events After Therapy) score for clinical markers and the GREAT+ score for the combination of clinical and genetic markers. The GREAT and GREAT+ scores were divided into classes according to recurrence rates. Higher recurrence rates were observed in GREAT score Class III (68%) compared with class II (44%) or Class I (16%). The GREAT+ score showed much higher rates of recurrence in Class IV+ (84%), compared with Class III+ (49%), Class II+ (21%) and Class I+ (4%).The largest benefit of the GREAT+ score is in GREAT score class II: addition of genotypes changes recurrence risk (and thereby management) in 38%.Our prediction model based on simple clinical assessment, supplemented with genotyping at intermediate risk, can be of great value in individualized treatment of newly diagnosed patients with Graves' hyperthyroidism in routine clinical practice.

  • Pharmacogenetics and pharmacogenomics as tools in cancer therapy.
    Rodríguez-Vicente AE, Lumbreras E, Hernández JM, et al. Pharmacogenetics and pharmacogenomics as tools in cancer therapy. [JOURNAL ARTICLE]Drug Metabol Personal Ther 2016 Feb 10.Pharmacogenetics and pharmacogenomics (PGx) are rapidly growing fields that aim to elucidate the genetic basis for the interindividual differences in drug response. PGx approaches have been applied to many anticancer drugs in an effort to identify relevant inherited or acquired genetic variations that may predict patient response to chemotherapy and targeted therapies. In this article, we discuss the advances in the field of cancer pharmacogenetics and pharmacogenomics, driven by the recent technological advances and new revolutionary massive sequencing technologies and their application to elucidate the genetic bases for interindividual drug response and the development of biomarkers able to personalize drug treatments. Specifically, we present recent progress in breast cancer molecular classifiers, cell-free circulating DNA as a prognostic and predictive biomarker in cancer, patient-derived tumor xenograft models, chronic lymphocytic leukemia genomic landscape, and current pharmacogenetic advances in colorectal cancer. This review is based on the lectures presented by the speakers of the symposium "Pharmacogenetics and Pharmacogenomics as Tools in Cancer Therapy" from the VII Conference of the Spanish Pharmacogenetics and Pharmacogenomics Society (SEFF), held in Madrid (Spain) on April 21, 2015.

  • Continuous Collection of Adeno-Associated Virus from Producer Cell Medium Significantly Increases Total Viral Yield.
    Benskey MJ, Sandoval IM, Manfredsson FP Continuous Collection of Adeno-Associated Virus from Producer Cell Medium Significantly Increases Total Viral Yield. [Journal Article]Hum Gene Ther Methods 2016 Feb; 27(1):32-45.The ability to efficiently produce large amounts of high-titer recombinant adeno-associated virus (AAV) is a prerequisite to the continued success of AAV as a gene therapy tool targeted toward large-animal preclinical studies or human clinical therapeutics. Current manufacturing procedures necessitate laborious and time-consuming purification procedures to obtain AAV particles of sufficient titer and purity for these demanding biomedical applications. The finding that AAV can be harvested and purified from producer cell medium may represent an efficient alternative to purifying AAV from cellular lysates. Here we sought to determine the maximum duration of time, and frequency within which AAV can be harvested from producer cell medium, in order to maximize the yield obtained from a single transfection preparation. Human embryonic kidney 293T cells were transfected with polyethylenimine to produce AAV2/5 expressing green fluorescent protein (GFP), and cellular medium was harvested every 2 days until a maximum duration of 19 days posttransfection. AAV2/5-GFP was released into producer cell medium at a steady state until 7 days posttransfection, at which time titers dropped dramatically. Harvesting medium every two days resulted in the maximum yield of AAV from a single preparation, and the cumulative yield of AAV harvested from the producer cell medium was 4-fold higher than the yield obtained from a traditional purification of AAV from cellular lysates. The AAV2/5 harvested from medium within the 7-day collection time-course mediated high levels of transduction in vivo, comparable to AAV2/5 harvested from cellular lysates. AAV purified from cell lysates showed increasing amounts of empty particles at 5 and 7 days posttransfection, whereas AAV purified from cell medium did not show an increase in the amount of empty particles throughout the 7-day time course. Finally, we extended these findings to AAV2/9, demonstrating that a comparable ratio of AAV2/9 particles are also released for up to 7 days posttransfection.

  • Baculovirus IE2 Stimulates the Expression of Heat Shock Proteins in Insect and Mammalian Cells to Facilitate Its Proper Functioning.
    Tung H, Wei SC, Lo HR, et al. Baculovirus IE2 Stimulates the Expression of Heat Shock Proteins in Insect and Mammalian Cells to Facilitate Its Proper Functioning. [Journal Article]PLoS One 2016; 11(2):e0148578.Baculoviruses have gained popularity as pest control agents and for protein production in insect systems. These viruses are also becoming popular for gene expression, tissue engineering and gene therapy in mammalian systems. Baculovirus infection triggers a heat shock response, and this response is crucial for its successful infection of host insect cells. However, the viral protein(s) or factor(s) that trigger this response are not yet clear. Previously, we revealed that IE2-an early gene product of the baculovirus-could form unique nuclear bodies for the strong trans-activation of various promoters in mammalian cells. Here, we purified IE2 nuclear bodies from Vero E6 cells and investigated the associated proteins by using mass spectrometry. Heat shock proteins (HSPs) were found to be one of the major IE2-associated proteins. Our experiments show that HSPs are greatly induced by IE2 and are crucial for the trans-activation function of IE2. Interestingly, blocking both heat shock protein expression and the proteasome pathway preserved the IE2 protein and its nuclear body structure, and revived its function. These observations reveal that HSPs do not function directly to assist the formation of the nuclear body structure, but may rather protect IE2 from proteasome degradation. Aside from functional studies in mammalian cells, we also show that HSPs were stimulated and required to determine IE2 protein levels, in insect cells infected with baculovirus. Upon inhibiting the expression of heat shock proteins, baculovirus IE2 was substantially suppressed, resulting in a significantly suppressed viral titer. Thus, we demonstrate a unique feature in that IE2 can function in both insect and non-host mammalian cells to stimulate HSPs, which may be associated with IE2 stabilization and lead to the protection of the its strong gene activation function in mammalian cells. On the other hand, during viral infection in insect cells, IE2 could also strongly stimulate HSPs and ultimately affect viral replication.

  • Mifepristone-inducible transgene expression in neural progenitor cells in vitro and in vivo.
    Hjelm BE, Grunseich C, Gowing G, et al. Mifepristone-inducible transgene expression in neural progenitor cells in vitro and in vivo. [JOURNAL ARTICLE]Gene Ther 2016 Feb 10.Numerous gene and cell therapy strategies are being developed for the treatment of neurodegenerative disorders. Many of these strategies use constitutive expression of therapeutic transgenic proteins, and although functional in animal models of disease, this method is less likely to provide adequate flexibility for delivering therapy to humans. Ligand-inducible gene expression systems may be more appropriate for these conditions, especially within the central nervous system. Mifepristone's ability to cross the blood-brain barrier makes it an especially attractive ligand for this purpose. We describe the production of a mifepristone-inducible vector system for regulated expression of transgenes within the central nervous system. Our inducible system used a lentivirus-based vector platform for the ex vivo production of mifepristone-inducible murine neural progenitor cells that express our transgenes of interest. These cells were processed through a series of selection steps to ensure the cells exhibited appropriate transgene expression in a dose-dependent and temporally controlled manner with minimal background activity. Inducible cells were then transplanted into the brains of rodents, where they exhibited appropriate mifepristone-inducible expression. These studies detail a strategy for regulated expression in the CNS for use in the development of safe and efficient gene therapy for neurological disorders.Gene Therapy accepted article preview online, 10 February 2016. doi:10.1038/gt.2016.13.

  • Characterizing Molecular Variants and Clinical Utilization of Next-generation Sequencing in Advanced Breast Cancer.
    Gurda GT, Ambros T, Nikiforova MN, et al. Characterizing Molecular Variants and Clinical Utilization of Next-generation Sequencing in Advanced Breast Cancer. [JOURNAL ARTICLE]Appl Immunohistochem Mol Morphol 2016 Feb 9.Women with advanced breast carcinomas have few therapeutic options. Recent advances in genomic profiling represent a new paradigm of cancer classification and treatment, but experience with genomic testing in a clinical setting remains limited. We retrospectively determined the genomic variants and correlate these with histology [histomorphologic subtype, nuclear grade, standard immunohistochemistry (IHC)] and clinical utilization (ordering, turnaround time, report review, and targeted therapy). Among 48 patients, 2 showed no genetic alterations, 11 (23%) showed variants of unclear significance only and 35 (73%) showed variant(s) affecting function (VaF) and/or variants of unclear significance. Overall, 119 variants were observed in 20 of 50 tested genes. Each patient had a unique molecular profile, with numerous (n=58) variants not previously reported in breast cancer. VaF detected in more than 2 patients included: TP53 (n=21), PIK3CA (n=20), and FGFR1 (n=3). VaF comprised 46 single nucleotide variants (79%), 7 amplifications (12%), 3 frameshifts (5%), 1 insertion (2%), and 1 deletion (2%). The tested samples had very high Ki67 index (average 57%±23%) and approximately half were hormone receptor and HER2 negative (25/46, 54%). Metastatic breast carcinomas showed a higher average VaF versus breast-localized tumors (1.3±0.99 vs. 0.18±0.60, P<0.05). Next-generation sequencing reports were promptly reported and reviewed (average 1 to 2 d) and 7 (∼25%) of potentially eligible patients received targeted therapy. Advanced breast cancers show unique landscapes of genetic variants. Most testing was done in late disease, often in metastatic and receptor-negative carcinomas. Next-generation sequencing results were promptly reported and reviewed, but the utilization of targeted therapies was limited.