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Neutralizing the EGF receptor in glioblastoma cells stimulates cell migration by activating uPAR-initiated cell signaling.
In glioblastoma (GBM), the EGF receptor (EGFR) and Src family kinases (SFKs) contribute to an aggressive phenotype. EGFR may be targeted therapeutically; however, resistance to EGFR-targeting drugs such as Erlotinib and Gefitinib develops quickly. In many GBMs, a truncated form of the EGFR (EGFRvIII) is expressed. Although EGFRvIII is constitutively active and promotes cancer progression, its activity is attenuated compared with EGF-ligated wild-type EGFR, suggesting that EGFRvIII may function together with other signaling receptors in cancer cells to induce an aggressive phenotype. In this study, we demonstrate that in EGFRvIII-expressing GBM cells, the urokinase receptor (uPAR) functions as a major activator of SFKs, controlling phosphorylation of downstream targets, such as p130Cas and Tyr-845 in the EGFR in vitro and in vivo. When EGFRvIII expression in GBM cells was neutralized, either genetically or by treating the cells with Gefitinib, paradoxically, the cells demonstrated increased cell migration. The increase in cell migration was explained by a compensatory increase in expression of urokinase-type plasminogen activator, which activates uPAR-dependent cell signaling. GBM cells that were selected for their ability to grow in vivo in the absence of EGFRvIII also demonstrated increased cell migration, due to activation of the uPAR signaling system. The increase in GBM cell migration, induced by genetic or pharmacologic targeting of the EGFR, was blocked by Dasatinib, highlighting the central role of SFKs in uPAR-promoted cell migration. These results suggest that compensatory activation of uPAR-dependent cell signaling, in GBM cells treated with targeted therapeutics, may adversely affect the course of the disease by promoting cell migration, which may be associated with tumor progression
Immunocytochemical Evidence for Golgi Vesicle Involvement in Milk Fat Globule Secretion.
The exact mechanism of secretion of the milk fat globule (MFG) from the mammary secretory cell is still controversial. We have previously suggested close involvement of Golgi vesicles in this process. This paper provides direct immunocytochemical evidence that butyrophilin is present in the Golgi stack and vesicles in ovine and caprine mammary glands. We suggest that it is the butyrophilin in the Golgi vesicle membrane that forms the specific association with the adipophilin on the lipid surface in the cytoplasm. Exocytosis of the associated Golgi vesicle will then initiate the process of MFG secretion. Further exocytosis of associated Golgi vesicles will continue and complete the process. Areas of the plasmalemma that have butyrophilin delivered by previous non-lipid associated Golgi exocytoses may also contribute to the process of forming the milk fat globule membrane (MFGM).This is the author accepted manuscript. The final version is available from SAGE via http://dx.doi.org/10.1369/002215541560891
Hereditary sensory and autonomic neuropathies: types II, III, and IV
The hereditary sensory and autonomic neuropathies (HSAN) encompass a number of inherited disorders that are associated with sensory dysfunction (depressed reflexes, altered pain and temperature perception) and varying degrees of autonomic dysfunction (gastroesophageal reflux, postural hypotention, excessive sweating). Subsequent to the numerical classification of four distinct forms of HSAN that was proposed by Dyck and Ohta, additional entities continue to be described, so that identification and classification are ongoing. As a group, the HSAN are rare diseases that affect both sexes. HSAN III is almost exclusive to individuals of Eastern European Jewish extraction, with incidence of 1 per 3600 live births. Several hundred cases with HSAN IV have been reported. The worldwide prevalence of HSAN type II is very low. This review focuses on the description of three of the disorders, HSAN II through IV, that are characterized by autosomal recessive inheritance and onset at birth. These three forms of HSAN have been the most intensively studied, especially familial dysautonomia (Riley-Day syndrome or HSAN III), which is often used as a prototype for comparison to the other HSAN. Each HSAN disorder is likely caused by different genetic errors that affect specific aspects of small fiber neurodevelopment, which result in variable phenotypic expression. As genetic tests are routinely used for diagnostic confirmation of HSAN III only, other means of differentiating between the disorders is necessary. Diagnosis is based on the clinical features, the degree of both sensory and autonomic dysfunction, and biochemical evaluations, with pathologic examinations serving to further confirm differences. Treatments for all these disorders are supportive
The Alaotra gentle lemur: Population estimation and subsequent implications
Durrell Wildlife Conservation Trust (DWCT) has conducted since 1994 several censusā on the population of the Alaotran gentle lemur to observe the development of the population in time and space
LNCS
This paper presents a foundation for refining concurrent programs with structured control flow. The verification problem is decomposed into subproblems that aid interactive program development, proof reuse, and automation. The formalization in this paper is the basis of a new design and implementation of the Civl verifier
Heterogeneous photodegradation of bisphenol A with iron oxides and oxalate in aqueous solution
Author name used in this publication: F. B. LiAuthor name used in this publication: X. Z. LiAuthor name used in this publication: X. M. LiAuthor name used in this publication: T. X. Liu2006-2007 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
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