Tumor-homing cytotoxic human induced neural stem cells for cancer therapy

Engineered neural stem cells (NSCs) are a promising approach to treating glioblastoma (GBM). The ideal NSC drug carrier for clinical use should be easily isolated and autologous to avoid immune rejection. We transdifferentiated (TD) human fibroblasts into tumor-homing early-stage induced NSCs (h-iNSCTE), engineered them to express optical reporters and different therapeutic gene products, and assessed the tumor-homing migration and therapeutic efficacy of cytotoxic h-iNSCTE in patient-derived GBM models of surgical and nonsurgical disease. Molecular and functional analysis revealed that our single-factor SOX2 TD strategy converted human skin fibroblasts into h-iNSCTE that were nestin+ and expressed pathways associated with tumor-homing migration in 4 days. Time-lapse motion analysis showed that h-iNSCTE rapidly migrated to human GBM cells and penetrated human GBM spheroids, a process inhibited by blockade of CXCR4. Serial imaging showed that h-iNSCTE delivery of the proapoptotic agent tumor necrosis factor-A-related apoptosis-inducing ligand (TRAIL) reduced the size of solid human GBM xenografts 250-fold in 3 weeks and prolonged median survival from 22 to 49 days. Additionally, h-iNSCTE thymidine kinase/ganciclovir enzyme/prodrug therapy (h-iNSCTE-TK) reduced the size of patient-derived GBM xenografts 20-fold and extended survival from 32 to 62 days. Mimicking clinical NSC therapy, h-iNSCTE-TK therapy delivered into the postoperative surgical resection cavity delayed the regrowth of residual GBMs threefold and prolonged survival from 46 to 60 days. These results suggest that TD of human skin into h-iNSCTE is a platform for creating tumor-homing cytotoxic cell therapies for cancer, where the potential to avoid carrier rejection could maximize treatment durability in human trials

Effectiveness of the global protected area network in representing species diversity

The Fifth World Parks Congress in Durban, South Africa, announced in September 2003 that the global network of protected areas now covers 11.5% of the planet's land surface. This surpasses the 10% target proposed a decade earlier, at the Caracas Congress, for 9 out of 14 major terrestrial biomes. Such uniform targets based on percentage of area have become deeply embedded into national and international conservation planning. Although politically expedient, the scientific basis and conservation value of these targets have been questioned. In practice, however, little is known of how to set appropriate targets, or of the extent to which the current global protected area network fulfils its goal of protecting biodiversity. Here, we combine five global data sets on the distribution of species and protected areas to provide the first global gap analysis assessing the effectiveness of protected areas in representing species diversity. We show that the global network is far from complete, and demonstrate the inadequacy of uniform—that is, 'one size fits all'—conservation targets

History of ESL Pronunciation Teaching

This chapter tells the story of over 150 years in the teaching of English as a second language (ESL) pronunciation. An analysis of historical resources may reveal a reliable history of pronunciation teaching. A consistent theme within the historical record is that prior to the second half of the nineteenth century pronunciation received little attention in L2 classrooms. Beginning in the 1850s and continuing for the next 30 years, early innovators such as Berlitz, Gouin, Marcel, and Predergast were rejecting and transitioning away from classical approaches. A change that resulted in pronunciation teaching\u27s considerably more consequential second wave was the formation in Paris during the period 1886-1889 of the International Phonetic Association. The 1950s-1970s coincide with a slow rise of attention to innovations in how to teach pronunciation. If we may speculate on the future of ESL pronunciation teaching, there is every reason to feel optimistic

Increased mesangial cell hyaluronan expression in lupus nephritis is mediated by anti-DNA antibody-induced IL-1β

The mechanism by which anti-DNA antibodies contribute to the pathogenesis of lupus nephritis (LN) remains to be fully elucidated. Hyaluronan (HA) is an important extracellular matrix constituent that accumulates during tissue injury, and participates in lymphocyte recruitment to sites of inflammation. The role of HA in the pathogenesis of LN has not been defined. We investigated the expression of HA in renal biopsies and circulating HA levels in patients with diffuse proliferative LN, and the effect of human anti-DNA antibodies on HA synthesis in cultured human mesangial cells (HMC). HA expression was increased in the mesangium, and in the periglomerular and tubular distribution in LN kidney biopsies. LN patients showed increased levels of circulating HA, especially during active disease, which correlated with anti-DNA antibody titers (r=0.35, P=0.0234). Anti-DNA antibodies isolated during active LN but not remission increased de novo synthesis of 3H-labeled HA, which was accompanied by induction of HA synthase (HAS) II transcription, and enhanced IL-1β, IL-6, and tumor necrosis factor-α secretion in HMC (P<0.001 for all). Only anti-DNA antibody induction of IL-1β enhanced HA synthesis, which was abrogated by inhibitors of de novo mRNA or protein synthesis. Our findings demonstrate that HA expression is significantly increased within the mesangium in diffuse proliferative LN mediated through anti-DNA antibody-induced IL-1β. Given that HA plays a pivotal role during inflammatory responses, influences cellular behavior and assists in the recruitment of lymphocytes to sites of injury, it is likely that HA contributes to the pathogenesis of LN. © 2006 International Society of Nephrology.link_to_subscribed_fulltex

Engineering Endochondral Bone: In Vitro Studies

Chitosan scaffolds have been shown to possess biological and mechanical properties suitable for tissue engineering and clinical applications. In the present work, chitosan sponges were evaluated regarding their ability to support cartilage cell proliferation and maturation, which are the first steps in endochondral bone formation. Chitosan sponges were seeded with chondrocytes isolated from chicken embryo sterna. Chondrocyte/chitosan constructs were cultured for 20 days, and treated with retinoic acid (RA) to induce chondrocyte maturation and matrix synthesis. At different time points, samples were collected for microscopic, histological, biochemical, and mechanical analyses. Results show chondrocyte attachment, proliferation, and abundant matrix synthesis, completely obliterating the pores of the sponges. RA treatment caused chondrocyte hypertrophy, characterized by the presence of type X collagen in the extracellular matrix and increased alkaline phosphatase activity. In addition, hypertrophy markedly changed the mechanical properties of the chondrocyte/chitosan constructs. In conclusion, we have developed chitosan sponges with adequate pore structure and mechanical properties to serve as a support for hypertrophic chondrocytes. In parallel studies, we have evaluated the ability of this mature cartilage scaffold to induce endochondral ossification