A novel paradigm in tumor biology suggests that non-small cell lung cancer (NSCLC) metastasis is driven by lung cancer stem cell-like cells (LCSCs), but the underlying mechanisms remain unclear. Here, we aim to investigate biological function of CD44 in regulating metastatic trait of LCSCs and its underlying mechanisms. In this study, we found that CD133 CD44 cells which were derived from primary lung adenocarcinoma (LAC) possessed cancer stem cell-like features. Furthermore, CD44 was demonstrated functionally crucial to drive metastatic potential of CD133 CD44 LCSCs by in vitro and in vivo experiments. In patient cohorts, high level of CD44 predicted increased probability of metastasis. Significantly, microarray revealed that FoxM1 and key proteins of Wnt/β-catenin pathway were up-regulated in CD133 CD44 LCSCs compared with those in CD133 CD44 cells. Then, we demonstrated that CD44 promoted metastatic activity in CD133 CD44 LCSCs through Wnt/β-catenin pathway and FoxM1 was the downstream target of Wnt/β-catenin pathway. Meanwhile, our findings indicated that FoxM1 promoted metastatic activity in CD133 CD44 LCSCs by inducing EMT and Twist was a direct transcriptional target of FoxM1. Collectively, CD44, both a functional biomarker and therapeutic target, promoted CD133 CD44 LCSCs metastasis by Wnt/β-catenin-FoxM1-Twist signaling. This study provided support for the missing link between EMT and CSCs surface-marker and supplied a promising approach for elimination of LCSCs by targeting CD44-Wnt/β-catenin-FoxM1-Twist signaling. © 2015 Wiley Periodicals, Inc.

Background: MicroRNAs (miRNAs) play important roles in many biological processes, including cancer development. Among those miRNAs, miR-143 shows tumor-suppressive activity in some human cancers. However, the function and mechanism of miR-143 in lung cancer cells remains unknown. Here we explored the role of miR-143 in lung cancer. Results: According to qRT-PCR, we found that miR-143 was notably down-regulated in 19 NSCLC tissues and 5 cell lines. In vitro experiments showed us that miR-143 could significantly suppress the migration and invasion of NSCLC cell lines while it had no effects on the growth of NSCLC cell lines, and in vivo metastasis assay showed the same results. Finally, we found that the mechanism of miR-143 inhibiting the migration and invasion of NSCLC might be through targeting CD44v3. Conclusions: The up-regulated miR-143 in lung cancer could significantly inhibit cell migration and invasion, and this might work through targeting CD44v3, which was newly identified by us.

Drugs derived from traditional Chinese medicines (TCM) include both single chemical entities and multi-component preparations.

Platinum-based chemotherapies have long been used as a standard treatment in non-small cell lung cancer (NSCLC). However, cisplatin resistance is a major problem that restricts the use of cisplatin. Lung cancer stem cells (LCSCs) represent a subpopulation that is responsible for chemo-resistance. We aim to investigate the biological function of SLC27A2 and its underlying mechanisms in regulating chemo-resistance to cisplatin in LCSCs. Here, our findings testified that CD166 cells which were derived from fresh primary NSCLC samples displayed stem cell-like features and were resistant to chemotherapy drug cisplatin. In patient cohort, we found the presence of a variable fraction of CD166 cells in 24 out of 25 primary NSCLC samples. Significantly, SLC27A2 expression was reduced in CD166 LCSCs. Reduced SLC27A2 correlated chemo-response and poor patient survival. Our results indicated that enhanced SLC27A2 expression sensitized CD166 LCSCs to cisplatin by in vitro and in vivo experiments. Microarray profiling showed that the expression of Bmi1 and ABCG2 was enhanced in p-SLC27A2-LCSCs compared with that in pc3.1DNA-LCSCs. Furthermore, we demonstrated that reduced SLC27A2 induced chemo-resistance in CD166 LCSCs by negatively regulating Bmi1-ABCG2 signaling, and ABCG2 was a direct transcriptional target of Bmi1. Thus, this study widens the window for identification and targeting of a cisplatin-resistant population and contributes to the development of potential therapeutics to improve the current treatment modalities in NSCLC. © 2015 Wiley Periodicals, Inc.

ShuFengJieDu capsule (SFJDC), a traditional Chinese medicine (TCM) that contains eight medicinal herbs, has been extensively utilized for the treatment of acute lung injury (ALI) and respiratory infections for more than 30 years in China. SFJDC has also been listed in the official guidelines of the China Food and Drug Administration (CFDA) due to its stable clinical manifestations. However, the underlying mechanism of SFJDC during ALI repair remains unclear. In the present study, we explored the protective and therapeutic mechanisms of SFJDC in a rat model by performing qualitative and label-free quantitative proteomics studies. After establishing lipopolysaccharide (LPS)-induced ALI rat models, we profiled macrophage cells isolated from freshly resected rat lung tissues derived from ALI models and ALI rat lung tissue sections using a high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) shotgun proteomics approach to identify changes in the expression levels of proteins of interest. On the basis of our proteomics results and the results of a protein dysregulation analysis of ALI rat lung tissues and rat lung macrophages, AKT1 was selected as a putative key factor that may play an important role in mediating the effects of SFJDC treatment during ALI progression. Follow-up validation studies demonstrated that AKT1 expression effectively regulates various ALI-related molecules, and Gene Ontology analysis indicated that SFJDC-treated ALI rat macrophages were influenced by AKT1-based networks. Gain- and loss-of-function analyses following lentivirus-AKT1 or lentivirus-si-AKT1 infection in macrophages also indicated that AKT1 was essential for the development of ALI due to its ability to regulate oxidative stress, apoptosis, or inflammatory responses. In summary, SFJDC effectively modulated anti-inflammatory and immunomodulation activity during ALI, potentially due to AKT1 regulation during ALI progression. New insights into SFJDC mechanisms may facilitate the development of novel pharmaceutical strategies to control the expression of inflammatory factors.

Autophagy is a highly conserved self-digestion process to promote cell survival in response to nutrient starvation and other metabolic stresses in eukaryotic cells. Dysregulation of this system is linked with numerous human diseases, including cancers. ATG4B, a cysteine protease required for autophagy, cleaves the C-terminal amino acid of ATG8 family proteins to reveal a C-terminal glycine which is necessary for ATG8 proteins conjugation to phosphatidylethanolamine (PE) and insertion to autophagosome precursor membranes. However, the mechanism governing the protein stability of ATG4B in human cancer cells is not fully understood. In this study, tandem affinity purification/mass spectrometry (TAP/MS) were applied to the investigation of the interaction between ATG4B and potential candidate proteins. Then, co-immunoprecipitation (Co-IP) and GST-pull down assays indicated that the candidate protein-SLC27A4 directly interacts with ATG4B in lung cancer cell lines. Intriguingly, we also found that ATG4B protein expression was increased in parallel with SLC27A4 in lung cancer cell lines as well as lung tumor tissues. However, relevant functional research of SLC27A4 in autophagy or oncotherapy has not been investigated before. In this study, we hypothesized that SLC27A4 might act as a mediator of ATG4B, in some respects, through the protein binding directly. Further, we found that the high expression level of SLC7A4 increased the ATG4B stability and was conducive to rapid reaction to everolimus (RAD001)-induced autophagy in human lung cancer cells. As expected, the results showed that SLC27A4 could help to maintain the protein stability and intracellular concentration of ATG4B, thereby triggering rapid autophagy through releasing ATG4B to cytoplasm under conditions of reduced nutrient availability or during stress of chemotherapy in lung cancer cells. Reduced SLC27A4 by si-RNA also showed the enhanced therapeutic efficiency of everolimus, doxorubicin, and cisplatin in human lung cancer cell lines. Collectively, this study may help researchers better understand the mechanism of autophagy vitality in human cancers and SLC27A4/ATG4B complex might act as a new potential therapeutic target of lung tumor chemotherapy.

Low molecular weight heparin (LMWH) improving the cancer survival has been attracting attention for many years. Our previous study found that LMWH (Fraxiparine) strongly downregulated the invasive, migratory, and adhesive ability of human lung adenocarcinoma A549 cells. Here, we aimed to further identify the antitumor effects and possible mechanisms of Fraxiparine on A549 cells and human highly metastatic lung cancer 95D cells. The ability of cell invasion, migration, and adhesion were measured by Transwell, Millicell, and MTT assays. FITC-labeled phalloidin was used to detect F-actin bundles in cells. Chemotactic migration was analyzed in a modified Transwell assay. Measurement of protein expression and phosphorylation activity of PI3K, Akt, and mTOR was performed with Western blot. Our studies found that Fraxiparine significantly inhibited the invasive, migratory, and adhesive characteristics of A549 and 95D cells after 24 h incubation and showed a dose-dependent manner. Fraxiparine influenced the actin cytoskeleton rearrangement of A549 and 95D cells by preventing F-actin polymerization. Moreover, Fraxiparine could significantly inhibit CXCL12-mediated chemotactic migration of A549 and 95D cells in a concentration-dependent manner. Furthermore, Fraxiparine might destroy the interaction between CXCL12-CXCR4 axis, then suppress the PI3K-Akt-mTOR signaling pathway in lung cancer cells. For the first time, our data indicated that Fraxiparine could significantly inhibit the motility of lung cancer cells by restraining the actin cytoskeleton reorganization, and its related mechanism might be through inhibiting PI3K-Akt-mTOR signaling pathway mediated by CXCL12-CXCR4 axis. Therefore, Fraxiparine would be a potential drug for lung cancer metastasis therapy.

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