LncRNA surfactant associated 1 activates large tumor suppressor kinase 1/Yes-associated protein pathway via modulating hypoxic exosome-delivered miR-4766-5p to inhibit lung adenocarcinoma metastasis.

LncRNA surfactant associated 1 (SFTA1P) exhibits low expression in non-small cell lung cancer (NSCLC) tissues as compared with that in adjacent tissues, and may play a suppressing role in NSCLC. However, the effect and mechanism of SFTA1P on the metastasis of lung adenocarcinoma (LUAD) remain undefined, which are thus investigated in this research. Herein, potential impacts of SFTA1P on LUAD were determined through the Cancer Genome Atlas (TCGA) database and Gene Expression Profiling Interactive Analysis (GEPIA). After knockdown/overexpression of SFTA1P, the metastatic ability of LUAD cells was evaluated by molecular biology experiments (cell counting kit-8 assay, scratch test, Transwell assay and Western blot). The effect of SFTA1P on Yes-associated protein (YAP) nuclear translocation was assessed by Western blot. Hypoxia-induced exosomes were extracted for LUAD metastasis analysis. The targeting relationship of SFTA1P/miR-4766-5p/large tumor suppressor kinase 1 (LATS1) was verified by dual-luciferase reporter assay and molecular biology experiments. Xenograft and lung metastasis models were constructed for in vivo validation. SFTA1P was lowly expressed in LUAD, which was associated with the poor prognosis of patients with LUAD. Up-regulated SFTA1P prevented the metastasis of LUAD cells and the nuclear translocation of YAP. Hypoxia-induced exosomes stimulated LUAD cell metastasis, but inhibited the SFTA1P and LATS1/YAP axes. MiR-4766-5p acted as an intermediate "bridge" for SFTA1P to regulate LATS1. SFTA1P repressed xenograft growth and LUAD cell metastasis. To sum up, SFTA1P activates hypoxic exosome-delivered miR-4766-5p through modulating LATS1/YAP pathway, thereby suppressing LUAD cell metastasis, which may serve as a suitable target for the LUAD therapy.

Zhang W ，Bai M ，Liu K ，Tan J ，Ma J ，Zhao J ，Hou P ... -  《-》

LINC02535/miR-30a-5p/GALNT3 axis contributes to lung adenocarcinoma progression via the NF- κ B signaling pathway.

Li Y ，Zhao J ，Zhang W ，Wang A ，Jiao M ，Cai X ，Zhu J ，Liu Z ，Huang JA ... -  《-》

Circular RNA circ_0067741 regulates the Hippo/YAP pathway to suppress lung adenocarcinoma progression by targeting microRNA-183-5p.

Mo J ，Nie H ，Zeng C ，Han H ，Xu P ，Shi X ... -  《-》

LncRNA LINC00511 promotes COL1A1-mediated proliferation and metastasis by sponging miR-126-5p/miR-218-5p in lung adenocarcinoma.

Lung adenocarcinoma (LUAD) is currently the leading cause of cancer-related death worldwide. Long noncoding RNAs (lncRNAs) play key roles in tumor occurrence and development as crucial cancer regulators. The present study aimed to explore the molecular mechanism and regulatory network of Linc00511 in LUAD and to identify new potential therapeutic targets for LUAD. Real-time quantitative polymerase chain reaction (RT-qPCR) was performed to determine the relative Linc00511 levels in LUAD tissues and cells. The proliferation, apoptosis, migration, and invasion abilities of LUAD cells were assessed by a Cell Counting Kit-8 (CCK-8) assay, a colony formation assay, flow cytometry, and a Transwell assay. Changes in hsa_miR-126-5p, hsa_miR-218-5p, and COL1A1 expression were analyzed using western blotting and RT-qPCR. Targeted binding between miR-126-5p/miR-218-5p and Linc00511 or COL1A1 was verified with a luciferase reporter system and confirmed by an RNA pulldown assay. The participation of the PI3K/AKT signaling pathway was confirmed via western blotting. Xenograft animal experiments were performed to detect the impact of Linc00511 on LUAD tumor growth in vivo. In the present work, we observed that Linc00511 was upregulated in LUAD tissues and cells. Loss/gain-of-function experiments indicated that knockdown of Linc00511 significantly inhibited LUAD cell proliferation, migration and invasion and promoted LUAD cell apoptosis, whereas overexpression of Linc00511 showed the opposite effects. In addition, we determined that Linc00511 promoted COL1A1-mediated cell proliferation and cell motility by sponging miR-126-5p and miR-218-5p. Moreover, Linc00511 activated the PI3K/AKT signaling pathway through upregulation of COL1A1. Finally, silencing of Linc00511 inhibited LUAD tumor growth in vivo. Linc00511 acts as a competing endogenous RNA to regulate COL1A1 by targeting miR-126-5p and miR-218-5p, thereby promoting the proliferation and invasion of LUAD cells.

Wang Y ，Mei X ，Song W ，Wang C ，Qiu X ... -  《BMC Pulmonary Medicine》

Exosomal long noncoding RNA MLETA1 promotes tumor progression and metastasis by regulating the miR-186-5p/EGFR and miR-497-5p/IGF1R axes in non-small cell lung cancer.

Lung cancer is the most common and deadliest cancer worldwide, and approximately 90% of all lung cancer deaths are caused by tumor metastasis. Tumor-derived exosomes could potentially promote tumor metastasis through the delivery of metastasis-related molecules. However, the function and underlying mechanism of exosomal long noncoding RNA (lncRNA) in lung cancer metastasis remain largely unclear. Cell exosomes were purified from conditioned media by differential ultracentrifugation and observed using transmission electron microscopy, and the size distributions were determined by nanoparticle tracking analysis. Exosomal lncRNA sequencing (lncRNA-seq) was used to identify long noncoding RNAs. Cell migration and invasion were determined by wound-healing assays, two-chamber transwell invasion assays and cell mobility tracking. Mice orthotopically and subcutaneously xenografted with human cancer cells were used to evaluate tumor metastasis in vivo. Western blot, qRT‒PCR, RNA-seq, and dual-luciferase reporter assays were performed to investigate the potential mechanism. The level of exosomal lncRNA in plasma was examined by qRT‒PCR. MS2-tagged RNA affinity purification (MS2-TRAP) assays were performed to verify lncRNA-bound miRNAs. Exosomes derived from highly metastatic lung cancer cells promoted the migration and invasion of lung cancer cells with low metastatic potential. Using lncRNA-seq, we found that a novel lncRNA, lnc-MLETA1, was upregulated in highly metastatic cells and their secreted exosomes. Overexpression of lnc-MLETA1 augmented cell migration and invasion of lung cancer. Conversely, knockdown of lnc-MLETA1 attenuated the motility and metastasis of lung cancer cells. Interestingly, exosome-transmitted lnc-MLETA1 promoted cell motility and metastasis of lung cancer. Reciprocally, targeting lnc-MLETA1 with an LNA suppressed exosome-induced lung cancer cell motility. Mechanistically, lnc-MLETA1 regulated the expression of EGFR and IGF1R by sponging miR-186-5p and miR-497-5p to facilitate cell motility. The clinical datasets revealed that lnc-MLETA1 is upregulated in tumor tissues and predicts survival in lung cancer patients. Importantly, the levels of exosomal lnc-MLETA1 in plasma were positively correlated with metastasis in lung cancer patients. This study identifies lnc-MLETA1 as a critical exosomal lncRNA that mediates crosstalk in lung cancer cells to promote cancer metastasis and may serve as a prognostic biomarker and potential therapeutic target for lung cancer diagnosis and treatment.

Hsu XR ，Wu JE ，Wu YY ，Hsiao SY ，Liang JL ，Wu YJ ，Tung CH ，Huang MF ，Lin MS ，Yang PC ，Chen YL ，Hong TM ... -  《JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH》