ABSTRACT
PURPOSE: The long noncoding RNA LINC00261 was reported to be involved in carcinogenesis and has been validated as a tumor suppressor in pancreatic cancer (PC); however, how LINC00261 is regulated has not been fully examined. Here, we attempted to investigate the upstream and downstream targets of LINC00261 in PC. METHODS: LINC00261 expression in PC tissues was examined by the Gene Expression Omnibus (GEO) datasets and the Gene Expression Profiling Interactive Analysis (GEPIA) database. The quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays were performed to detect the expression level of LINC00261 in PC cells. The location of LINC00261 in PC cells was identified by RNA fluorescence in situ hybridization (RNA-FISH). Cell Counting Kit-8 (CCK-8), cell apoptosis assay, transwell invasion and migration assays testified the critical role of LINC00261 in PC. The luciferase reporter assay was applied to confirm the binding of LINC00261 to its upstream transcription factor KLF13. The changes in LINC00261 related target protein levels were analyzed by Western blotting assay. RESULTS: LINC00261 was significantly lower in PC tissues and was mainly concentrated in the nucleus. Overexpression of LINC00261 inhibited the invasion and migration of PC cells. Mechanistically, transcription factor KLF13 was confirmed to inhibit the epithelial-mesenchymal transition (EMT) process of PC cells by promoting the transcription of LINC00261 and suppressing the expression of metastasis-associated proteins, such as matrix metalloproteinase MMP2 and vimentin, thus inhibiting the metastasis of PC. CONCLUSION: LINC00261 regulates PC cell metastasis through the "KLF13-LINC00261-mTOR-P70S6K1-S6" signaling pathway, which provides a significant set of potential PC therapeutic targets.
Subject(s)
Kruppel-Like Transcription Factors , MicroRNAs , Pancreatic Neoplasms , RNA, Long Noncoding , Cell Cycle Proteins , Cell Line, Tumor , Cell Movement/genetics , Cell Proliferation/genetics , Epithelial-Mesenchymal Transition , Humans , In Situ Hybridization, Fluorescence , Kruppel-Like Transcription Factors/genetics , MicroRNAs/genetics , MicroRNAs/metabolism , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/pathology , RNA, Long Noncoding/genetics , RNA, Long Noncoding/metabolism , Repressor Proteins , Signal Transduction , TOR Serine-Threonine Kinases/genetics , TOR Serine-Threonine Kinases/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Up-Regulation , Pancreatic NeoplasmsABSTRACT
A new quassinoid, 11-O-trans-p-coumaroyl amarolide (1) was isolated from Castela texana, and the structure was elucidated by spectroscopic analysis. Compound 1 is the first coumaroyl quassinoid derivative to have been isolated from nature. The known compounds amarolide (2), chaparrinone, chaparrin, glaucarubolone, holacanthone, and 15-O-beta-D-glucopyranosyl glaucarubol were also isolated. All isolated compounds were tested for their cytotoxicity and antiprotozoal activities.