The Expression and Biological Significance of PD-L1 on Lung Cancer Cell Lines

Background and objective Tumor-associated PD-L1 expression was recently shown to promote T-cell apoptosis and proposed as a potential mechanism of immune evasion by tumors. On the basis of the ability of tumor-associated PD-L1 to mediate activated T-cell death, it is likely that manipulation of the PD-L1 pathway at defined time points during the development of the T-cell antitumor immune response can enhance the efficacy of T-cell-based immunotherapy. Here, the levels of expression of PD-L1 on lung cancer cell lines and its role in interaction of CTL and target cells was investigated. Methods Human PBMC derived DCs were loaded with apoptotic tumor cells and stimulated by CD40 mAb (5C11). Tumor specific CTL was generated in vitro by autologous T cells co-cultured with mature DCs. Expression of PD-L1 on lung cancer cell lines H1299 and A549 were analyzed by FCM. JAM assay was used to detect the cytolytic activity of CTL with or without blocking PD-L1 by PD-L1 mAb respectively. The concentrations of IFN-γ in supernatants from distinct groups were analyzed by ELISA. Results Tumor cells-loaded mature DCs could induce the generation of the tumor specific CTL. Expression of PD-L1 was low on A549 cell, but high on H1299 cell. Blockade of PD-L1 on A549 could not improve cytolytic effect of CTL on target cells and IFN-γ production, but fragmentation of H1299 cells and IFN-γ production were significantly enhanced by the combination of PD-L1 mAb and CTL. Conclusion Expression of PD-L1 on lung cancer cell line can decrease the cytolytic effect of CTL on target cells

Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)

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. For example, 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 versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost 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 fi eld 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. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. 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. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. 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

Transformation of Two Cases of Lung Adenocarcinoma into Pulmonary Sarcomatoid Carcinoma following Treatment

Accumulating evidence shows that histologic transformation is involved in the drug resistance of lung cancer. Moreover, it is common for lung adenocarcinoma to transform into small-cell lung cancer or squamous cell carcinoma; however, clinical cases with sarcomatoid transformation have been rarely reported. Thus, both the diagnosis and treatment of lung adenocarcinoma with sarcomatoid transformation remain difficult. Here, we discuss two patients with lung adenocarcinoma with sarcomatoid transformation—analyzing the diagnosis, clinical features, immunohistochemical characteristics, therapy, and prognosis—with the hope that this report will be used as a reference for future treatment of these patients