27 research outputs found

    Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

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    In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

    Multicenter Phase II Trial of Sunitinib in the Treatment of Nongastrointestinal Stromal Tumor Sarcomas

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    PURPOSE To evaluate the potential benefit of continuous daily dosing sunitinib in patients with advanced nongastrointestinal stromal tumor (GIST) sarcomas. PATIENTS AND METHODS A total of 53 patients with advanced non-GIST soft tissue sarcomas received sunitinib 37.5 mg daily. Primary end point was Response Evaluation Criteria in Solid Tumors defined response. Secondary end points were stable disease at 16 and 24 weeks. [(18)F]-fluorodeoxyglucose positron emission tomography was performed on a subset of 24 patients at baseline and after 10 to 14 days of therapy. Results Forty-eight patients were eligible for response. One patient (desmoplastic round cell tumor [DSRCT]) achieved a confirmed partial response (PR) and remained on study for 56 weeks. Ten patients (20%) achieved stable disease for at least 16 weeks. Metabolic PR was seen in 10 (47%) of 21 of patients. Metabolic stable disease was seen in 11 (52%) of 21. There were no unexpected toxicities observed. CONCLUSION Sunitinib demonstrated notable evidence of metabolic response in several patients with non-GIST sarcoma. The relevance of disease control observed in subtypes with an indolent natural history is unknown, however, the durable disease control observed in DSRCT, solitary fibrous tumor, and giant cell tumor of bone suggests that future evaluation of sunitinib in these subtypes may be warranted

    An EGF receptor/Ral-GTPase signaling cascade regulates c–Src activity and substrate specificity

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    c–Src is a membrane-associated tyrosine kinase that can be activated by many types of extracellular signals, and can regulate the function of a variety of cellular protein substrates. We demonstrate that epidermal growth factor (EGF) and β–adrenergic receptors activate c–Src by different mechanisms leading to the phosphorylation of distinct sets of c–Src substrates. In particular, we found that EGF receptors, but not β(2)–adrenergic receptors, activated c–Src by a Ral-GTPase-dependent mechanism. Also, c–Src activated by EGF treatment or expression of constitutively activated Ral–GTPase led to tyrosine phosphorylation of Stat3 and cortactin, but not Shc or subsequent Erk activation. In contrast, c–Src activated by isoproterenol led to tyrosine phosphorylation of Shc and subsequent Erk activation, but not tyrosine phosphorylation of cortactin or Stat3. These results identify a role for Ral–GTPases in the activation of c–Src by EGF receptors and the coupling of EGF to transcription through Stat3 and the actin cytoskeleton through cortactin. They also show that c–Src kinase activity can be used differently by individual extracellular stimuli, possibly contributing to their ability to generate unique cellular responses
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