Long noncoding RNAs (lncRNAs) have emerged as important regulators in a variety of human diseases, including cancers. However, the overall biological roles and clinical significance of most lncRNAs in gastric carcinogenesis are not fully understood. We investigated the clinical significance, biological function, and mechanism of LINC01234 in gastric cancer. First, we analyzed LINC01234 alterations in gastric cancerous and noncancerous tissues through an analysis of sequencing data obtained from The Cancer Genome Atlas. Next, we evaluated the effect of LINC01234 on the gastric cancer cell proliferation and apoptosis, and its regulation of miR-204-5p by acting as a competing endogenous RNA (ceRNA). The animal model was used to support the experimental findings. We found that LINC01234 expression was significantly upregulated in gastric cancer tissues and was associated with larger tumor size, advanced TNM stage, lymph node metastasis, and shorter survival time. Furthermore, knockdown of LINC01234-induced apoptosis and growth arrest and inhibited tumorigenesis in mouse xenografts. Mechanistic investigations indicated that LINC01234 functioned as a ceRNA for miR-204-5p, thereby leading to the derepression of its endogenous target core-binding factor β (CBFB). LINC01234 is significantly overexpressed in gastric cancer, and LINC01234-miR-204-5p-CBFB axis plays a critical role in gastric cancer tumorigenesis. Our findings may provide a potential new target for gastric cancer diagnosis and therapy. .

Long noncoding RNAs (lncRNA) are a novel class of transcripts with no protein coding capacity, but with diverse functions in cancer cell proliferation, apoptosis, and metastasis. The lncRNA PVT1 is 1,716 nt in length and located in the chr8q24.21 region, which also contains the myelocytomatosis (MYC) oncogene. Previous studies demonstrated that MYC promotes PVT1 expression in primary human cancers. However, the expression pattern and potential biologic function of PVT1 in non-small cell lung cancer (NSCLC) is still unclear. Here, we found that PVT1 was upregulated in 105 human NSCLC tissues compared with normal samples. High expression of PVT1 was associated with a higher tumor-node-metastasis stage and tumor size, as well as poorer overall survival. Functional analysis revealed that knockdown of PVT1 inhibited NSCLC cell proliferation and induced apoptosis both in vitro and in vivo. RNA immunoprecipitation and chromatin immunoprecipitation assays demonstrated that PVT1 recruits EZH2 to the large tumor suppressor kinase 2 (LATS2) promoter and represses LATS2 transcription. Furthermore, ectopic expression of LATS2 increased apoptosis and repressed lung adenocarcinoma cell proliferation by regulating the Mdm2-p53 pathway. Taken together, our findings indicated that PVT1/EZH2/LATS2 interactions might serve as new target for lung adenocarcinoma diagnosis and therapy.

Chemotherapy is one of the basic treatments for cancers; however, drug resistance is mainly responsible for the failure of clinical treatment. The mechanism of drug resistance is complicated because of interaction among various factors including drug efflux, DNA damage repair, apoptosis and targets mutation. Long non-coding RNAs (lncRNAs) have been a focus of research in the field of bioscience, and the latest studies have revealed that lncRNAs play essential roles in drug resistance in breast cancer, gastric cancer and lung cancer, et al. Dysregulation of multiple targets and pathways by lncRNAs results in the occurrence of chemoresistance. In this review, we will discuss the mechanisms underlying lncRNA-mediated resistance to chemotherapy and the therapeutic potential of lncRNAs in future cancer treatment.

Long noncoding RNAs (lncRNAs) have emerged as important regulators in a variety of human diseases, including cancers. However, the biological function of these molecules and the mechanisms responsible for their alteration in gastric cancer (GC) are not fully understood. In this study, we found that lncRNA LINC00673 is significantly upregulated in gastric cancer. Knockdown of LINC00673 inhibited cell proliferation and invasion and induced cell apoptosis, whereas LINC00673 overexpression had the opposite effect. Online transcription factor binding site prediction analysis showed that there are SP1 binding sites in the LINC00673 promoter region. Next, luciferase reporter and chromatin immunoprecipitation (ChIP) assays provided evidence that SP1 could bind directly to the LINC00673 promoter region and activate its transcription. Moreover, mechanistic investigation showed that CADM4, KLF2, and LATS2 might be the underlying targets of LINC00673 in GC cells, and RNA immunoprecipitation, RNA pull-down, and ChIP assays showed that LINC00673 can interact with EZH2 and LSD1, thereby repressing KLF2 and LATS2 expression. Taken together, these findings show that SP1-activated LINC00673 exerts an oncogenic function that promotes GC development and progression, at least in part, by functioning as a scaffold for LSD1 and EZH2 and repressing KLF2 and LATS2 expression.

BackgroundNumerous studies have shown that long non-coding RNAs (lncRNAs) behave as a novel class of transcript during multiple cancer processes, such as cell proliferation, apoptosis, migration, and invasion. LINC00152 is located on chromosome 2p11.2, and has a transcript length of 828 nucleotides. The biological role of LINC00152 in LAD(lung adenocarcinoma) remains unknown.MethodsQuantitative reverse transcription PCR(qRT-PCR) was used to detect LINC00152 expression in 60 human LAD tissues and paired normal tissues. In vitro and in vivo studies showed the biological function of LINC00152 in tumour progression. RNA transcriptome sequencing technology was performed to identify the downstream suppressor IL24(interleukin 24) which was further examined by qRT-PCR, western bolt and rescue experiments. RNA immunoprecipitation (RIP), RNA pulldown, and Chromatin immunoprecipitation (ChIP) assays were carried out to reveal the interaction between LINC00152, EZH2 and IL24.ResultsLINC00152 expression was upregulated in 60 human LAD tissues and paired normal tissues. High levels of LINC00152 expression were correlated with advanced TNM stage, larger tumor size, and lymph node metastasis, as well as shorter survival time. Silencing of LINC00152 suppressed cell growth and induced cell apoptosis. LINC00152 knockdown altered the expression of many downstream genes, including IL24. LINC00152 could interact with EZH2 and inhibit IL24 transcription. Moreover, the ectopic expression of IL24 repressed cell proliferation and partly reversed LINC00152 overexpression-induced promotion of cell growth in LAD.ConclusionsOur study reveals an oncogenic role for LINC00152 in LAD tumorigenesis, suggesting that it could be used as a therapeutic target in LAD treatment.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-017-0581-3) contains supplementary material, which is available to authorized users.