Motor performance and functional ability in preschool- and early school-aged children with Juvenile Idiopathic Arthritis: a cross-sectional study

Objective  

To describe the level of motor performance and functional skills in young children with JIA.     

SPRED1 deletion confers resistance to MAPK inhibition in melanoma

Functional evaluation of genetic lesions can discover a role in cancer initiation and progression and help develop novel therapeutic strategies. We previously identified the negative MAPK regulator SPRED1 as a novel tumor suppressor in KIT-driven melanoma. Here, we show that SPRED1 is also frequently deleted in human melanoma driven by mutant BRAF. We found that SPRED1 inactivation in human melanoma cell lines and primary zebrafish melanoma conferred resistance to BRAF^V600E inhibition in vitro and in vivo. Mechanistically, SPRED1 loss promoted melanoma cell proliferation under mutant BRAF inhibition by reactivating MAPK activity. Consistently, biallelic deletion of SPRED1 was observed in a patient whose melanoma acquired resistance to MAPK-targeted therapy. These studies combining work in human cells and in vivo modeling in zebrafish demonstrate a new mechanism of resistance to BRAF^V600E inhibition in melanoma.     

Zebrafish as a cancer model system

The zebrafish, with its combination of forward genetics and vertebrate biology, has great potential as a cancer model system.     

Active TGF-β1 correlates with myofibroblasts and malignancy in the colorectal adenoma-carcinoma sequence

Transforming growth factor-β1 (TGF-β1), a cytokine involved in various stages of cancer, is produced as a latent complex and requires processing to become active. We have determined total and active TGF-β1 levels in homogenates of colorectal neoplasia. In contrast to total TGF-β levels, showing a stepwise increase in the mucosa-adenoma-carcinoma sequence, active TGF-β1 levels are increased only in carcinomas but not in premalignant adenomas. Furthermore, solely active TGF-β1 levels are associated with the stage of the carcinomas and worse patient prognosis. Active TGF-β1 levels correlated significantly with plasminogen activator inhibitor (PAI)-1, α-smooth muscle actin (SMA) and several matrix-remodeling proteinases. Interestingly, SMA levels are also significantly increased in colorectal carcinomas but not in adenomas, suggesting that despite the enhanced total TGF-β1 levels, myofibroblast accumulation is not (yet) occurring in these premalignant neoplasias. The correlation between active TGF-β1 and SMA expression in tumors indicates that tumor-promoting myofibroblasts might arise as a result of increased TGF-β1 activation. These data underline the significance of the interaction between malignant cells and (myo)-fibroblasts in the tumor microenvironment, modulating the biologic behavior of colorectal cancer. ( Cancer Sci 2009; 100: 663–670)     

Co-injection strategies to modify radiation sensitivity and tumor initiation in transgenic Zebrafish

The zebrafish has emerged as a powerful genetic model of cancer, but has been limited by the use of stable transgenic approaches to induce disease. Here, a co-injection strategy is described that capitalizes on both the numbers of embryos that can be microinjected and the ability of transgenes to segregate together and exert synergistic effects in forming tumors. Using this mosaic transgenic approach, gene pathways involved in tumor initiation and radiation sensitivity have been identified.     

Malignant prolactinoma with craniospinal metastasis in a 12-year-old boy

The authors report the clinical features of and imaging studies on a rare case of pediatric malignant prolactinoma. A 12-year-old boy presented with ataxia, blurred vision, and consciousness disturbance. He had received transcranial surgery and adjuvant radiotherapy. However, the tumor regrew with craniospinal metastasis 16 months after the operation. The relevant literature was reviewed regarding the clinical presentation, pathogenesis, treatment approaches, and prognosis of malignant prolactinoma.     

Block of AIDS-Kaposi's sarcoma (KS) cell growth, angiogenesis, and lesion formation in nude mice by antisense oligonucleotide targeting basic fibroblast growth factor. A novel strategy for the therapy of KS.

Kaposi's sarcoma (KS) is the most frequent tumor of HIV-1-infected individuals (AIDS-KS). Typical features of KS are proliferating spindle-shaped cells, considered to be the tumor cells of KS, and endothelial cells forming blood vessels. Basic fibroblast growth factor (bFGF), a potent angiogenic factor, is highly expressed by KS spindle cells in vivo and after injection in nude mice it induces vascular lesions closely resembling early KS in humans. Similar lesions are induced by inoculating nude mice with cultured spindle cells from AIDS-KS lesions (AIDS-KS cells) which produce and release bFGF. Here we show that phosphorothioate antisense (AS) oligonucleotides directed against bFGF mRNA (ASbFGF) inhibit both the growth of AIDS-KS cells derived from different patients and the angiogenic activity associated with these cells, including the induction of KS-like lesions in nude mice. These effects are due to the block of the production of bFGF which is required by AIDS-KS cells to enter the cell cycle and which, after release, mediates angiogenesis. The effects of ASbFGF are specific, dose dependent, achieved at low (0.1-1 microM), nontoxic, oligomer concentrations, and are reversed by the addition of bFGF to the cells, suggesting that ASbFGF oligomers are promising drug candidates for KS therapy.     

Zebrafish mutants with disrupted early T-cell and thymus development identified in early pressure screen

Generation of mature T lymphocytes requires an intact hematopoietic stem cell compartment and functional thymic epithelium. We used the zebrafish (Danio rerio) to isolate mutations that affect the earliest steps in T lymphopoiesis and thymic organogenesis. Here we describe the results of a genetic screen in which gynogenetic diploid offspring from heterozygous females were analyzed by whole-mount in situ hybridization for the expression of rag-1. To assess immediately if a global defect in hematopoiesis resulted in the mutant phenotype, alpha-embryonic globin expression was simultaneously assayed for multilineage defects. In this report, we present the results obtained with this strategy and show representative mutant phenotypes affecting early steps in T-cell development and/or thymic epithelial cell development. We discuss the advantage of this strategy and the general usefulness of the zebrafish as a model system for vertebrate lymphopoiesis and thymic organogenesis. Developmental Dynamics 237:2575-2584, 2008. (c) 2008 Wiley-Liss, Inc.     

O-imino esters of N,N-bis(2-chloroethyl)phosphorodiamidic acid. Synthesis, X-ray structure determination, and anticancer evaluation

Nine representatives of the title series of compounds [(ClCH2CH2)2NP(O)(NH2)ON = CRR'] were synthesized as potential anticancer prodrugs, based on the possibility of enzymatic reduction of the N-O bond to release the known cytotoxic agent phosphoramide mustard [1, (ClCH2CH2)2NP(O)(NH2)OH]. The dimethyl derivative (2, R = R' = CH3) exhibited a statistically significant, albeit low, level of anti-L1210 activity in mice. Derivative 2, which was shown by 31P NMR measurements to be very stable toward hydrolysis at 37 degrees C over a pH range of 5.7-7.4 (T1/2 congruent to 7-8 weeks), gave colorimetrically detectable amounts of alkylating material upon incubation with mouse liver slices: approximately 3-5% conversion after 20 min at 37 degrees C. A single-crystal X-ray study of 2 revealed an unusual hydrogen-bonded "ladder" and a very similar steric relationship for the NCH2CH2Cl and ON = CCH3 moieties.