α- L-iduronidase gene-based therapy using the phiC31 system to treat mucopolysaccharidose type I mice.

BACKGROUND: Mucopolysaccharidose type I (MPSI) is a lysosomal monogenic disease caused by mutations in the gene for α- L-iduronidase (IDUA). MPSI patients need a constant supply of IDUA to alleviate progression of the disease. IDUA gene transfer using integrative vectors might provide a definitive solution and support advancement to clinical trials, although studies have not yet been satisfactory. To achieve a stable IDUA gene expression in vivo, phiC31 was tested in the present study. METHODS: Several plasmid vectors were constructed and IDUA-/- mice were treated with cyclophosphamide and transfected with these vectors hydrodynamically via tail veins. IDUA expression was monitored over time. Treated and nontreated mice underwent an open-field test at age 8 months, and IDUA activity and glycosaminoglycan (GAG) content of tissues were evaluated. RESULTS: High levels of IDUA activity were detected initially (>1000 U/ml), although these levels decayed over time. The reinjection of vectors produced a similar profile of IDUA decay. Three out of six treated mice had IDUA activity in the livers, and also showed lower GAG content, reduced lysosomes and better locomotion. To investigate unsustained IDUA production, wild-type mice were submitted to the same gene therapy procedure, which generated a similar profile of IDUA decay. Anti-IDUA antibody was detected in the sera of these animals. In addition, we also found three methylated sites in the cytomegalovirus promoter region. CONCLUSIONS: phiC31-mediated gene therapy resulted in an important improvement in IDUA-/- mice, including locomotion, although the obstacles that need to be overcome to enable long-term gene therapy for MPSI are also noted.

Management of elderly patients with glioblastoma: current status with a focus on the post-operative radiation therapy.

Glioblastoma (GBM) is one of the most malignant primary intracranial neoplasms. This review aims to summarize the treatment of elderly patients with newly diagnosed GBM, with a focus on the radiation therapy (RT) approach. The available literature was reviewed, and we describe the most significant results relating to the post-operative approach of elderly GBM patients. Age limitations in randomized phase III studies have restricted the inclusion of elderly patients, and consequently, limited the generalizability of their results to this patient subset. Chronological age should not prohibit the best treatment, but instead, treatment decisions should consider patient functional status. RT showed efficacy and safety in the elderly population, without compromising quality of life. Hypofractionated RT is not inferior to standard RT. Reduction of overall RT schedule length mitigates the difficulties faced by elderly patients, improving treatment adherence. The addition of both concomitant and adjuvant temozolomide to standard RT is superior to either modality alone and should be the treatment of choice in the subset of patients with good/very good prognosis. It is reasonable to offer hypofractionated RT or temozolomide alone for poor prognosis, and best supportive care (BSC) for very poor prognosis elderly GBM patients. Although combined modality treatment is well established for the management of the good prognosis population, different RT schemes require further investigation with randomized controlled trials to determine the best regimen. A robust analysis of the molecular signatures of GBM in elderly patients might reveal opportunities for clinical protocol modifications to customize management in this group of patients.

The Anti-Tumor Effects of Adipose Tissue Mesenchymal Stem Cell Transduced with HSV-Tk Gene on U-87-Driven Brain Tumor.

Glioblastoma (GBM) is an infiltrative tumor that is difficult to eradicate. Treating GBM with mesenchymal stem cells (MSCs) that have been modified with the HSV-Tk suicide gene has brought significant advances mainly because MSCs are chemoattracted to GBM and kill tumor cells via a bystander effect. To use this strategy, abundantly present adipose-tissue-derived mesenchymal stem cells (AT-MSCs) were evaluated for the treatment of GBM in mice. AT-MSCs were prepared using a mechanical protocol to avoid contamination with animal protein and transduced with HSV-Tk via a lentiviral vector. The U-87 glioblastoma cells cultured with AT-MSC-HSV-Tk died in the presence of 25 or 50 µM ganciclovir (GCV). U-87 glioblastoma cells injected into the brains of nude mice generated tumors larger than 3.5 mm2 after 4 weeks, but the injection of AT-MSC-HSV-Tk cells one week after the U-87 injection, combined with GCV treatment, drastically reduced tumors to smaller than 0.5 mm2. Immunohistochemical analysis of the tumors showed the presence of AT-MSC-HSV-Tk cells only within the tumor and its vicinity, but not in other areas of the brain, showing chemoattraction between them. The abundance of AT-MSCs and the easier to obtain them mechanically are strong advantages when compared to using MSCs from other tissues.

Stereotactic radiosurgery for the treatment of Glomus Jugulare Tumors.

BACKGROUND: The glomus jugulare tumor is a slowly growing benign neoplasm originating from neural crest. There is a high morbidity associated with surgical resection of glomus jugulare. Radiosurgery play a relevant role as a therapeutic option in these tumors and its use has grown in popularity. The authors describe a retrospective series of 15 patients and reviewed the literature about the glomus jugulare tumors. METHODS: We reviewed retrospectively the data of 15 patients treated with stereotactic linear accelerator stereotactic radiosurgery (LINAC) radiosurgery between 2006 and 2011. RESULTS: The average tumor volume was 18.5 cm(3). The radiation dose to the tumor margin ranged between 12 and 20 Gy. The neurological status improved in three patients and remained unchanged in 12 patients. One patient developed a transient 7(th) nerve palsy that improved after clinical treatment. All tumors remained stable in size on follow-up with resonance magnetic images. CONCLUSIONS: The radiosurgery is a safe and effective therapy for patients with glomus jugulare tumor. Despite the short follow-up period and the limited number of patients analyzed, we can infer that radiosurgery produce a tumor growth control with low morbidity, and may be used as a good option to surgical resection in selected cases.