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- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 2. |
- Shen, Yang-mei, et al.
(författare)
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Novel gene hBiot2 is an independent prognostic factor in colorectal cancer patients
- 2012
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Ingår i: Oncology Reports. - : Spandidos Publications. - 1021-335X .- 1791-2431. ; 27:2, s. 376-382
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Tidskriftsartikel (refereegranskat)abstract
- The present study investigated the expression of the novel gene hBiot2 in colorectal cancer (CRC) and its relationships with clinicopathological variables in CRC patients. The expression of hBiot2 in 163 primary CRCs together with the corresponding normal mucosa, 36 liver metastases and 5 colon cancer cell lines was examined using real-time PCR. In situ hybridization (ISH) was performed to evaluate the localization of hBiot2 expression in CRC and normal mucosa. hBiot2 expression at the RNA level was localized in the nucleus of tumor cells and normal epithelial cells. The mean expression of hBiot2 in the CRCs (243.571 +/- 564.569) was higher compared to the normal mucosa (107.252 +/- 413.635, Pandlt;0.0001) and liver metastasis samples (42.002 +/- 40.809, P=0.0002). hBiot2 expression was increased from stages I + II to III (P=0.047), and no difference in the expression was found in stages III and IV (P=0.452). A high value of hBiot2 was associated with a poorer prognosis compared with a low value independently of gender, age, tumor site, stage and differentiation (P=0.007, RR 7.519, 95% Cl 1.729-32.704). Liver metastasis, smaller tumors, non-local recurrence and primary liver surgery alone were associated with a higher value of hBiot2 compared to larger tumors, local recurrence and repeated liver surgery (P=0.003, 0.044 and 0.026, respectively). An inverse relationship was found between hBiot2 expression and the metastatic potential of the colon cancer cell lines. Thus, increased expression of hBiot2 may be an early and interim event in the development of CRC. A higher expression of hBiot2 in primary CRC patients independently indicates a poorer prognosis.
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