Downregulated Long Non-Coding RNA MSC-AS1 Inhibits Osteosarcoma Progression and Increases Sensitivity to Cisplatin by Binding to MicroRNA-142.

BACKGROUND Osteosarcoma (OS) is the most prevalent malignant primary bone tumor, resulting from severe transformation of primitive mesenchymal cells, which induces osteogenesis. Long non-coding RNA (lncRNA) MSC-AS1 triggers osteogenic differentiation by sponging microRNA (miR)-140-5p. The present study assessed the mechanism of lncRNA MSC-AS1 in OS biological features and sensitivity to cisplatin (DDP) by binding to miR-142. MATERIAL AND METHODS Firstly, lncRNA MSC-AS1 expression in OS tissues and cells was analyzed. OS cells were transfected with silenced MSC-AS1 to determine its role in OS biological behaviors, and we also assessed the effect of MSC-AS1 on OS sensitivity to DDP. Then, website prediction and dual-luciferase reporter gene assay were utilized for verification of the binding site between MSC-AS1 and miR-142. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis were performed to determine the effect of MSC-AS1 on expression of miR-142, cyclin-dependent kinase 6 (CDK6), and the PI3K/AKT signaling pathway. Xenograft transplantation was also applied to confirm the in vitro experiments. RESULTS Overexpressed MSC-AS1 was associated with poor prognosis of OS patients. OS cell proliferation, invasion, and migration were reduced after silencing MSC-AS1, while cell apoptosis was enhanced. Moreover, silencing MSC-AS1 made OS cells more sensitive to DDP. Interestingly, MSC-AS1 knockdown induced miR-142 expression and reduced CDK6 levels, thereby decreasing the protein expression of p-PI3K/t-PI3K and p-AKT/t-AKT. Silencing MSC-AS1 repressed OS progression in vivo. CONCLUSIONS Our study demonstrated that silencing MSC-AS1 inhibited OS biological behaviors by enhancing miR-142 to decrease CDK6 and inactivating the PI3K/AKT axis. Our results may provide new insights for OS treatment.

Identification of lapatinib sensitivity-related genes by integrative functional module analysis.

BACKGROUND: Globally, gastric carcinoma (GC) is one of the most commonly encountered malignancies and is the second highest contributor to cancer mortality. Lapatinib is a potent, orally-bioavailable small-molecule inhibitor of both epidermal growth factor receptor and human epidermal growth factor receptor-2 tyrosine kinases, and is administered to treat GC. However, a large proportion of patients either develop resistance to or do not respond to lapatinib, often because the treatment activates alternative signaling pathways. It is, therefore, vital to identify the key pathways which mediate resistance to lapatinib treatment. METHODS: The lapatinib sensitivity-related genes were extracted from the CellMiner database (version 2.2) using "NCI-60 Analysis Tools". The differentially expressed genes (DEGs) in gastric cancer were derived from The Cancer Genome Atlas (TCGA) database, the protein-protein interaction (PPI) network was derived from the Human Protein Reference Database (HPRD), and the Database for Annotation, Visualization and Integrated Discovery (DAVID) facilitated the functional analysis. The cell function was tested by CCK-8 cell viability assay, colony formation assay, acridine orange/ethidium bromide (AO/EB) staining, and Transwell assay. RESULTS: The functional linkage networks of lapatinib sensitivity were constructed. Two modules were identified, and pathway analysis indicated that these modules were involved in several pathways, including the neuroactive ligand-receptor interaction network and the Rap1 signaling pathway. Finally, the breast cancer anti-estrogen resistance 1 (BCAR1) gene was selected for further study with lapatinib-resistant SUN216 cells (SUN216/LR). We found the expression of BCAR1 was upregulated in SUN216/LR cells compared to SUN216 cells. The IC50 of lapatinib in SUN216/LR cells was reduced upon BCAR1 knockdown, as measured by a CCK-8 assay. A clonogenic assay showed fewer SUN216/LR colonies with BCAR1 knockdown and lapatinib treatment. CONCLUSIONS: In brief, we efficiently identified those crucial modules highly related to lapatinib sensitivity in GC by using a topological network method. BCAR1 was identified as a potentially critical gene that plays a role in lapatinib sensitivity, and experiments confirmed that BCAR1 might contribute to lapatinib resistance in GC. These results provide further insight into the molecular basis of lapatinib sensitivity and may offer novel strategies for the future treatment of GC.

Upregulated long noncoding RNA LINC01296 indicates a dismal prognosis for pancreatic ductal adenocarcinoma and promotes cell metastatic properties by affecting EMT.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease that responds poorly to chemotherapy and radiotherapy and whose incidence has increased worldwide. Long noncoding RNAs have been demonstrated to play important roles in cancer initiation and progression. Long intergenic non-coding RNA 01296 (LINC01296) has been reported to be upregulated in several malignancies, but the clinical relevance and biological role of LINC01296 in PDAC are still unclear. METHODS: RT-qPCR was performed to evaluate the expression of LINC01296 in 85 pared PDAC tissue samples and a panel of PDAC cell lines. The clinical value and prognostic role of LINC01296 in patients with PDAC were further explored. Furthermore, we explored the functional roles of LINC01296 depletion in PANC-1 and SW1990 cells, including cell proliferation, apoptosis, migration, invasion, and epithelial-to-mesenchymal transition (EMT). RESULTS: LINC01296 was enhanced in PDAC tissues and cell lines, and this overexpression was correlated with advanced tumor stages and positive lymph node metastasis in patients with PDAC. In addition, upregulation of LINC01296 was an independent prognostic predictor for patients with PDAC after surgery. Moreover, silencing of LINC01296 followed by treatment with small interfering RNAs suppressed cell proliferation and promoted cell apoptosis by affecting the Bcl-2/caspase-3 pathway. Importantly, LINC01296 attenuation impaired the migratory and invasive potential partly by reversing EMT. CONCLUSIONS: Overall, our work may help to develop a novel prognostic biomarker and therapeutic target for PDAC.

Preparation, characterization, and growth mechanism of a novel aligned nanosquare anatase in large quantities in the presence of TMAOH.

Monodispersed and well-aligned samples of TiO(2) nanosquares were synthesized in large quantities in the presence of tetramethylammonium hydroxide (TMAOH) for the first time. These nanosquares were single crystals characterized by slightly truncated shape bounded by {101} facets. XRD, AFM, FT-IR, Raman scattering, TEM and HRTEM were employed to characterize the as-prepared samples. The possible microreaction mechanism was discussed. As a result, TMAOH accelerates the formation of crystalline anatase and plays a structural template role to modify the particle shape to nanosquare. Moreover, TMAOH reacted with hydrolysates and formed layered structural complex compound.