Xiaoying Guan

BACKGROUND: Our pilot study using miRNA PCR array found that miRNA-29b (miR-29b) is differentially expressed in primary cultured CD133-positive A549 cells compared with CD133-negative A549 cells. METHODS: Ten human non-small cell lung cancer (NSCLC) cell lines and samples from thirty patients with NSCLC were analyzed for the expression of miR-29b by quantitative RT-PCR. Bioinformatics analysis combined with tumor metastasis PCR array showed the potential target genes for miR-29b. miR-29b lentivirus and inhibitors were transfected into NSCLC cells to investigate its role on regulating cell proliferation which was measured by CCK-8 assay in vitro and nude mice xenograft tumor assay in vivo. Cell motility ability was evaluated by transwell assay. The target genes of miR-29b were determined by luciferase assay, quantitative RT-PCR and western blot. RESULTS: Bioinformatics analysis combined with tumor metastasis PCR array showed that matrix metalloproteinase 2 (MMP2) and PTEN could be important target genes of miR-29b. The expression of miR-29b was down regulated in NSCLC tissues compared to the normal tissues. Clinicopathological analysis demonstrated that miR-29b had significant negative correlation with lymphatic metastasis. The gain-of-function studies revealed that ectopic expression of miR-29b decreased cell proliferation, migration and invasion abilities of NSCLC cells. In contrasts, loss-of-function studies showed that inhibition of miR-29b promoted cell proliferation, migration and invasion of NSCLC cells in vitro. Nude mice xenograft tumor assay confirmed that miR-29b inhibited lung cancer growth in vivo. High-invasion (A549-H) and low-invasion (A549-L) NSCLC cell sublines from A549 cells were created by using the repeated transwell assay aimed to confirm the effect of miR-29b on migration and invasion of NSCLC. Furthermore, the dual-luciferase reporter assay demonstrated that miR-29b inhibited the expression of the luciferase gene containing the 3'-UTRs of MMP2 and PTEN mRNA. Western blotting and quantitative RT-PCR indicated that miR-29b down-regulated the expression of MMP2 at the protein and mRNA levels. CONCLUSION: Taken together, our results demonstrate that miR-29b serves as a tumor metastasis suppressor, which suppresses NSCLC cell metastasis by directly inhibiting MMP2 expression. The results show that miR-29b may be a novel therapeutic candidate target to slow NSCLC metastasis.

In this study, Ganoderma lucidum crude polysaccharide (GLP) was found to have protective effect on liver damage in mice caused by restraint stress through improving oxidative status. Two polysaccharides, including a neutral β-glucan (GLPB2) and an acidic β-glucan (GLPC2) were purified from GLP through anion-exchange chromatography (AEC) combined with gel permeation. GLPC2, with an average molecular weight of 20.56 kDa, exhibited stronger hepatoprotective effect against H2O2-induced liver injury in HepG2 cells compared to GLPB2. Glycosidic residues and NMR analysis comprehensively revealed that GLPC2 contained d-Glcp-(1→, →3)-d-Glcp-(1→, →4)-d-Glcp-(1→, →6)-d-Glcp-(1→, →3, 6)-d-Glcp-(1 → and → 4)-d-GlcpA-(1 → . AEC can be an effective technique for separating β-glucans into neutral and acidic fractions by different ionic strength buffer. The findings provided a theoretical basis for the potential application of G. lucidum polysaccharides as a hepatoprotective in food and pharmaceutical industry.

Hydrogen sulfide releasing agents (or H2S donors) have been recognized gasotransmitters with potent cytoprotective and anticancer properties. However, the clinical application of H2S donors has been hampered by their fast H2S-release, instability, and lack of tumor targeting, despite the unclear molecular mechanism of H2S action. Here we rationally designed an amphiphilic pentapeptide (RGDFF) to coassemble with the de novo designed thiol-activated H2S donors (CL2/3) into nanocarriers for targeted therapy of non-small-cell lung cancer, which has been proved as a one-stone-three-birds strategy. The coassembly approach simply solved the solubility issue of CL2/3 by the introduction of electron-donating groups (phenyl rings) to slow down the H2S release while dramatically improving their biocompatible interface, circulation time, slow release of H2S, and tumor targeting. Experimental results confirmed that as-prepared coassembled nanocarriers can significantly induce the intrinsic apoptotic, effectively arrest cell cycle at the G2/M phase, inhibit H2S-producing enzymes, and lead to mitochondrial dysfunction by increasing intracellular ROS production in H1299 cells. The mouse tumorigenesis experiments further confirmed the in vivo anticancer effects of the coassembled nanocarriers, and such treatment made tumors more sensitive to radiotherapy then improved the prognosis of tumor-bearing mice, which holds great promise for developing a new combined approach for NSCLC.

Annexin A1 (ANXA1) is a member of the annexin superfamily. Previous studies have reported that ANXA1 is highly expressed in various types of malignant tumor; however, its role in the progression of non‑small cell lung cancer (NSCLC) remains to be fully clarified. The present study aimed to investigate the oncogenic role of ANXA1 in NSCLC cells in vitro. RNA interference was used to downregulate ANXA1 expression in A549 and H1299 cells using a small interfering RNA lentiviral vector. Subsequently, cell proliferation and migration were detected using Cell Counting kit‑8, clone formation, wound healing and Transwell chamber assays. Successful transfection was confirmed using fluorescence microscopy, which demonstrated that ANXA1 had been efficiently inhibited. ANXA1 knockdown suppressed the proliferation, migration and invasion of NSCLC cells. In conclusion, the present study provided evidence suggesting that ANXA1 may contribute to the growth and invasion of NSCLC cell lines, and ANXA1 may be exploited as an in vitro therapeutic target for the treatment of NSCLC.

BACKGROUND: Epithelial-to mesenchymal transition (EMT) involves in metastasis, causing loss of epithelial polarity. Metastasis is the major cause of carcinoma-induced death, but mechanisms are poorly understood. Here we identify differentially expressed in adenocarcinoma of the lung-1 (DAL-1), a protein belongs to the membrane-associated cytoskeleton protein 4.1 family, as an efficient suppressor of EMT in lung cancer. METHODS: The relationship between DAL-1 and EMT markers were analyzed by using immunohistochemistry in the clinical lung cancer tissues. Quantitative real-time PCR and western blot were used to characterize the expression of the EMT indicator mRNAs and proteins in DAL-1 overexpressed or knockdown cells. DAL-1 combined proteins were assessed by co-immunoprecipitation. RESULTS: DAL-1 levels were strongly reduced even lost in lymph node metastasis and advanced pathological stage of human lung carcinomas. Overexpression of DAL-1 altered the expression of numerous EMT markers, such as E-cadherin, β-catenin Vimentin and N-cadherin expression, meanwhile changed the morphological shape of lung cancer cells, and whereas silencing DAL-1 had an opposite effect. DAL-1 directly combined with E-cadherin promoter and regulated its expression that could be the reason for impairing EMT and decreasing cell migration and invasion. Strikingly, HSPA5 was found as DAL-1 direct binding protein. CONCLUSIONS: These results suggest that tumor suppressor DAL-1 could also attenuate EMT and be important for tumor metastasis in the early transformation process in lung cancer.