SummaryAAA domain-containing 3A (ATAD3A) is a member of the AAA-ATPase family. Three forms of ATAD3 have been identified: ATAD3A, ATAD3B and ATAD3C. In this study, we examined the type and expression of ATAD3 in lung adenocarcinoma (LADC). Expression of ATAD3A was detected by reverse transcription-polymerase chain reaction, immunoblotting, immunohistochemistry and confocal immunofluorescent microscopy. Our results show that ATAD3A is the major form expressed in LADC. Silencing of ATAD3A expression increased mitochondrial fragmentation and cisplatin sensitivity. Serum deprivation increased ATAD3A expression and drug resistance. These results suggest that ATAD3A could be an anti-apoptotic marker in LADC.

We examined gene expression of hepatocyte growth factor (HGF) and HGF receptor (HGFR), or product of proto-oncogene c-met (c-met), in smokers and nonsmokers with adenocarcinoma (ADC) by suppression subtractive hybridization and microarray techniques. Expression of HGF and c-met was confirmed by RT-PCR. HGF content in the respective tumor mass and nontumor lung tissue was measured by ELISA. HGF in pathologic samples was localized by immunohistochemistry and in situ hybridization. Our results indicate that overexpression of HGFR was frequently detected in ADC cells, whereas overexpression of HGF was detected in alveolar type II (ATII) cells. Overexpression of HGF was correlated with cigarette smoking and tumor stages. In vitro, HGF expression was evaluated in isolated murine ATII cells and in 12 ADC cell lines, and we found that nicotine activated HGF expression in ATII cells and lung cancer cells.

Our previous study had shown that advanced stages of lung adenocarcinomas (ADC) was frequently associated with overexpression of hepatocyte growth factor (HGF), which has multipotent and anti-apoptotic activities. In this study, we examined the effect of HGF on gene expression of apoptosis-inducing factor (AIF) and cisplatin sensitivity in lung ADC cells. Expression of AIF was determined by immunocytochemistry and confocal immunofluorescence microscopy. Our data show that addition of HGF suppressed AIF expression and increased cisplatin resistance. The effect could be through HGF receptor and its downstream effector, focal adhesion kinase (FAK). Interestingly, knockout of FAK gene increased AIF expression and drug sensitivity. Re-introduction of FAK gene, on the other hand, restored drug resistance. These results suggested that HGF might induce cisplatin resistance via c-Met to activate FAK and down-regulate AIF expression.

Human immunodeficiency virus 1 (HIV-1) viral protein R (Vpr) has been shown to induce host cell death by increasing the permeability of mitochondrial outer membrane (MOM). The mechanism underlying the damage to the mitochondria by Vpr, however, is not clearly illustrated. In this study, Vpr that is introduced, via transient transfection or lentivirus infection, into the human embryonic kidney cell line HEK293, human CD4 + T lymphoblast cell line SupT1, or human primary CD4 + T cells serves as the model system to study the molecular mechanism of Vpr-mediated HIV-1 pathogenesis. The results show that Vpr injures MOM and causes a loss in membrane potential (MMP) by posttranscriptionally reducing the expression of mitofusin 2 (Mfn2) via VprBP-DDB1-CUL4A ubiquitin ligase complex, gradually weakening MOM, and increasing mitochondrial deformation. Vpr also markedly decreases cytoplasmic levels of dynamin-related protein 1 (DRP1) and increases bulging in mitochondria-associated membranes (MAM), the specific regions of endoplasmic reticulum (ER) which form physical contacts with the mitochondria. Overexpression of Mfn2 and DRP1 significantly decreased the loss of MMP and apoptotic cell death caused by Vpr. Furthermore, by employing time-lapse confocal fluorescence microscopy, we identify the transport of Vpr protein from the ER, via MAM to the mitochondria. Taken together, our results suggest that Vpr-mediated cellular damage may occur on an alternative protein transport pathway from the ER, via MAM to the mitochondria, which are modulated by Mfn2 and DRP1.

BackgroundEpithelial-to-mesenchymal transition (EMT) has, in recent years, emerged as an important tumor cell behavior associated with high metastatic potential and drug resistance. Interestingly, protein SUMOylation and hepatocyte growth factor could respectively reduce the effect of small molecule inhibitors on tyrosine kinase activity of mutated epidermal growth factor receptor of lung adenocarcinomas (LADC). The actual mechanism is yet to be resolved.MethodsImmunohistochemistry was used to stain proteins in LADC specimens. Protein expression was confirmed by Western blotting. In vitro, expression of proteins was determined by Western blotting and immunocytochemistry. Levels of circular RNA were determined by reverse transcription-polymerase chain reaction.ResultsSAE2 and cirRNA CCDC66 were highly expressed in LADC. Expression of SAE2 was mainly regulated by EGFR; however, expression of cirRNA CCDC66 was positively regulated by FAK and c-Met but negatively modulated by nAchR7α. EGFR-resistant H1975 also highly expressed cirRNA CCDC66. Immediate response of hypoxia increased phosphorylated c-Met, SAE2, and epithelial-to-mesenchymal transition. Either activation of FAK or silencing of nAchR7α increased cirRNA CCDC66.ConclusionsHGF/c-Met regulates expression of SAE2 and cirRNA CCDC66 to increase EMT and drug resistance of LADC cells. Multimodality drugs concurrently aiming at these targets would probably provide more benefits for cancer patients.Electronic supplementary materialThe online version of this article (10.1186/s13045-018-0557-9) contains supplementary material, which is available to authorized users.

Previous reports have indicated that patients with severe acute respiratory syndrome (SARS)-associated coronavirus infection could develop atypical pneumonia with fulminant pulmonary edema. However, the target cells of SARS viral infection have not been characterized in detail. We report the pathologic findings of the lung in 3 cases of SARS. Chest radiographs at 2 to 3 weeks of infection revealed an atypical pneumonia with pulmonary consolidation, a clinical characteristic of SARS infection. The presence of the SARS virus was determined by nested reverse transcription-polymerase chain reaction (RT-PCR), and the infected cells were identified by in situ hybridization in open-lung biopsy and postmortem necropsy specimens. Expression of SARS virus-encoded RNA was detected in all 3 cases by RT-PCR, and the SARS viral signal was localized in pneumocytes by using in situ hybridization.

Our data suggest that high expression of ATAD3A is an independent biomarker for radioresistance in GBM. ATAD3A could be a potential target for therapy.

Aims:  The aims of this study were to identify and characterize the novel thermophilic, cellulose‐degrading bacterium Paenibacillus sp. strain B39. Methods and Results:  Strain B39 was closely related to Paenibacillus cookii in 16S rRNA gene sequence. Nonetheless, this isolate can be identified as a novel Paenibacillus sp. with respect to its physiological characteristics, biochemical reactions, and profiles of fatty acid compositions. A cellulase with both CMCase and avicelase activities was secreted from strain B39 and purified by ion‐exchange chromatography. By sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis, the molecular weight of B39 cellulase was determined as 148 kDa, which was much higher than other cellulases currently reported from Paenibacillus species. The enzyme showed a maximum CMCase activity at 60°C and pH 6·5. Addition of 1 mmol l−1 of Ca2+ markedly enhanced both CMCase and avicelase activities of the enzyme. Conclusions:  We have identified and characterized a novel thermophilic Paenibacillus sp. strain B39 which produced a high‐molecular weight cellulase with both CMCase and avicelase activities. Significance and Impact of the Study:  Based on the ability to hydrolyse CMC and avicel, the cellulase produced by Paenibacillus sp. strain B39 would have potential applications in cellulose biodegradation.