LncRNA Linc00511 promotes osteosarcoma cell proliferation and migration through sponging miR-765

Long noncoding RNA (lncRNA) Linc00511 is a novel lncRNA, and it was reported to play important roles in the progression and carcinogenesis of several tumors. However, the expression and biological roles of Linc00511 in osteosarcoma were still unknown. In this research, we showed that the expression of Linc00511 was upregulated in osteosarcoma samples and cell lines. Ectopic expression of Linc00511 promoted osteosarcoma cell growth, colony formation, and migration. Moreover, overexpression of Linc00511 enhanced the epithelial-mesenchymal transition progression in osteosarcoma cell. In addition, we showed that elevated expression of Linc00511 suppressed microRNA-765 (miR-765) expression and promoted apurinic/apyrimidinic endonuclease 1 (APE1) expression in osteosarcoma cell. The expression of miR-765 was downregulated in osteosarcoma cells and samples and was negatively related to Linc00511 expression in osteosarcoma tissues. Ectopic expression of miR-765 inhibited osteosarcoma cell growth and migration. Furthermore, we showed that Linc00511 overexpression promoted MG-63 cells proliferation, colony formation, and migration via downregulation of miR-765. These results suggested that Linc00511 played as an oncogene in the development of osteosarcoma.     

Long noncoding RNA Linc00339 promotes triple-negative breast cancer progression through miR-377-3p/HOXC6 signaling pathway

Recently, long noncoding RNAs (lncRNAs) have become the key gene regulators and prognostic biomarkers in various cancers. Through microarray data, Linc00339 was identified as a candidate oncogenic lncRNA. We compared the expression levels of Linc00339 in several breast cancer cell lines and normal mammary gland epithelial cell line. The effects of Linc00339 on tumor progression were examined both in vitro and in vivo. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were applied to evaluate the functions of Linc00339, miR-377-3p, and HOXC6 on cell proliferation. Flow cytometry analysis was used to detect apoptosis and cell cycle distribution. Overall survival (OS) was analyzed using data from The Cancer Genome Atlas and molecular taxonomy of breast cancer international consortium (METABRIC). Dual luciferase assay and RNA immunoprecipitation were performed to confirm the interaction between Linc003339 and miR-377-3p. Linc00339 was increased in breast cancer cell lines compared with the normal epithelial cell. Through in vitro and in vivo experiments, Linc00339 overexpression promoted triple-negative breast cancer (TNBC) proliferation, inhibited cell cycle arrest, and suppressed apoptosis. Silencing of Linc00339 obtained the opposite effects. Mechanistic investigations demonstrated that Linc00339 could sponge miR-377-3p and regulate its expression. Higher expression of miR-377-3p indicated longer OS in breast cancer patients, especially in TNBC patients. Overexpression of miR-377-3p retarded TNBC cell growth through regulating cell cycle distribution and apoptosis. And miR-377-3p was involved in Linc00339-mediated TNBC proliferation through regulating HOXC6 expression. Knockdown of HOXC6 inhibited TNBC progression. In conclusion, our results illuminated that the novel Linc00339/miR-377-3p/HOXC6 axis played a critical role in TNBC progression and might be a promising therapeutic target for TNBC treatment.     

Upregulated long noncoding RNA Linc00261 in pre-eclampsia and its effect on trophoblast invasion and migration via regulating miR-558/TIMP4 signaling pathway

Pre-eclampsia (PE) is a leading cause of maternal and perinatal morbidity and mortality but the exact underlying mechanisms of PE pathogenesis remain elusive. Accumulated data suggested that the long noncoding RNAs (lncRNAs) play important roles in the pathogenesis of PE. The present study identified the changes of lncRNA Linc00261 in PE and its effects on trophoblasts invasion and migration. Our results showed that the expression of Linc00261 was upregulated in placental tissues of PE women compared with those of healthy pregnant women. Overexpression of Linc00261 suppressed cell invasion and migration, induced cell apoptosis, and caused cell-cycle arrest at G₀/G₁ phase of HTR-8/SVneo cells; while knockdown of Linc00261 had the opposite effects on the HTR-8/SVneo cells. Mechanistic studies showed Linc00261 functioned as a competing endogenous RNA for miR-558 in HTR-8/SVneo cells, and miR-558 was negatively regulated by Linc00261. The expression level of miR-558 in the PE group was significantly lower than the control group, and the expression level of Linc00261 was negatively correlated with the expression level of miR-558 in the placental tissues of women with PE. Furthermore, miR-558 was found to negatively regulate the expression of TIMP metallopeptidase inhibitor 4 (TIMP4) via targeting the 3′ untranslated region in the HTR-8/SVneo cells. Overexpression of miR-558 increased HTR-8/SVneo cell invasion and migration, which was attenuated by TIMP4 overexpression. More importantly, both overexpression of miR-558 and knockdown of TIMP4 partially reversed the suppressive effects of Linc00261 overexpression on cell invasion and migration of HTR-8/SVneo cells. Collectively, our results for the first time showed the upregulation of Linc00261 in the placental tissues of severe PE patients. The mechanistic results indicated that Linc00261 exerted the suppressive effects on the trophoblast invasion and migration via targeting miR-558/TIMP4 axis, which may involve in the pathogenesis of PE.     

Aberrant hypermethylation of miR-9 genes in gastric cancer

Carcinogenesis of the stomach involves multiple steps including genetic mutation or epigenetic alteration of tumor suppressor genes or oncogenes. Recently, tumor suppressive miRNAs have been shown to be deregulated by aberrant hypermethylation during gastric cancer progression. In this study, we demonstrate that three independent genetic loci encoding for miR-9 (miR-9-1, miR-9-2 and miR-9-3) are simultaneously modified by DNA methylation in gastric cancer cells. Methylation-mediated silencing of these three miR-9 genes can be reactivated in gastric cancer cells through 5-Aza-dC treatment. Subsequent analysis of the expression levels of miR-9 showed that it was significantly down-regulated in gastric cancers compared with adjacent normal tissues (P value < 0.005). A similar tendency toward a tumor-specific DNA methylation pattern was shown for miR-9-1, miR-9-2 and miR-9-3 in 72 primary human gastric cancer specimens. Ectopic expression of miR-9 inhibited cell proliferation, migration and invasion, suggesting its tumor suppressive potential in gastric cancer progression.     

MicroRNA-574-5p Was Pivotal for TLR9 Signaling Enhanced Tumor Progression via Down-Regulating Checkpoint Suppressor 1 in Human Lung Cancer

Accumulating data suggested that functional expression of Toll-like receptors (TLRs) in tumor cells was involved in tumor progression. Our previous study demonstrated that TLR9 signaling could enhance the tumor progression of human lung cancer cells in vitro and in vivo. We further showed that miR-574-5p was the mostly up-regulated miRNA in human lung cancer cells under TLR9 signaling by miRNA array analysis. Here we characterized the potential role of miRNA-574-5p in enhanced tumor progression induced by TLR9 signaling in human lung cancer. We confirmed that TLR9 signaling effectively elevated the expression of miR-574-5p in human lung cancer cells. Notably, we found that down-regulation of miRNA-574-5p using miR-574-5p inhibitor in vitro or miR-574-5p sponge in vivo significantly abrogated the enhanced tumor progression induced by TLR9 signaling. Further studies showed that miR-574-5p was an important player associated with enhanced tumor progression of human lung cancer cells. Notably, we identified checkpoint suppressor 1 (Ches1) as the dominant direct target for miRNA-574-5p to confer the TLR9 signaling enhanced tumor progression. We revealed that over-expression of Ches1 significantly inhibited the cell cycle entry of human lung cancer cells. Finally, we revealed that the expression of miR-574-5p was positively correlated with TLR9 and reversely correlated with Ches1 in lung cancer patients. Our findings not only facilitated the further understanding of the crosstalk between miRNAs and TLRs in tumor biology, but also provided novel potential candidates for treatment of cancer.     

miR-204 functions as a tumor suppressor by regulating SIX1 in NSCLC

The involvement of miR-204 in lung cancer development is unclear. In our study, we analyzed the expression of miR-204 in tumor- and adjacent-tissue samples from 141 patients with non-small cell lung cancer (NSCLC). MiR-204 expression was decreased in tumor samples compared with non-cancerous tissue-derived controls. Moreover, miR-204 expression negatively correlated with homeobox protein SIX1 expression, tumor size and metastasis. MiR-204 silencing in miR-204-positive NSCLC cell lines promoted cell invasion and proliferation. Concomitantly, MiR-204 overexpression resulted in reduced cell proliferation and invasion, upregulated E-cadherin and downregulated N-cadherin and Vimentin expression. SIX1 was identified as a potential target of miR-204, and SIX1 silencing partially compromised the invasive and proliferative capacity of miR-204-deficient cells. Thus, miR-204 may be involved in the NSCLC development.     

miR-30b,Down-Regulated in Gastric Cancer,Promotes Apoptosis and Suppresses Tumor Growth by Targeting Plasminogen Activator Inhibitor-1

Background

Gastric cancer is one of the most common malignant diseases worldwide. Emerging evidence has shown that microRNAs (miRNAs) are associated with tumor development and progression. Our previous studies have revealed that H. pylori infection was able to induce the altered expression of miR-30b in gastric epithelial cells. However, little is known about the potential role of miR-30b in gastric cancer.

Methods

We analyzed the expression of miR-30b in gastric cancer cell lines and human gastric cancer tissues. We examined the effect of miR-30b mimics on the apoptosis of gastric cancer cells in vitro by flow cytometry (FCM) and caspase-3/7 activity assays. Nude mouse xenograft model was used to determine whether miR-30b is involved in tumorigenesis of gastric cancer. The target of miR-30b was identified by bioinformatics analysis, luciferase assay and Western blot. Finally, we performed the correlation analysis between miR-30b and its target expression in gastric cancer.

Results

miR-30b was significantly down-regulated in gastric cancer cells and human gastric cancer tissues. Enforced expression of miR-30b promoted the apoptosis of gastric cancer cells in vitro, and miR-30b could significantly inhibit tumorigenicity of gastric cancer by increasing the apoptosis proportion of cancer cells in vivo. Moreover, plasminogen activator inhibitor-1 (PAI-1) was identified as the potential target of miR-30b, and miR-30b level was inversely correlated with PAI-1 expression in gastric cancer. In addition, silencing of PAI-1 was able to phenocopy the effect of miR-30b overexpression on apoptosis regulation of cancer cells, and overexpression of PAI-1 could suppressed the effect of promoting cell apoptosis by miR-30b, indicating PAI-1 is potentially involved in miR-30b-induced apoptosis on cancer cells.

Conclusion

miR-30b may function as a novel tumor suppressor gene in gastric cancer by targeting PAI-1 and regulating the apoptosis of cancer cells. miR-30b could serve as a potential biomarker and therapeutic target against gastric cancer.     

Linc00426 accelerates lung adenocarcinoma progression by regulating miR-455-5p as a molecular sponge

Increasing lines of evidence indicate the role of long non-coding RNAs (LncRNAs) in gene regulation and tumor development. Hence, it is important to elucidate the mechanisms of LncRNAs underlying the proliferation, metastasis, and invasion of lung adenocarcinoma (LUAD). We employed microarrays to screen LncRNAs in LUAD tissues with and without lymph node metastasis and revealed their effects on LUAD. Among them, Linc00426 was selected for further exploration in its expression, the biological significance, and the underlying molecular mechanisms. Linc00426 exhibits ectopic expression in LUAD tissues and cells. The ectopic expression has been clinically linked to tumor size, lymphatic metastasis, and tumor differentiation of patients with LUAD. The deregulation of Linc00426 contributes to a notable impairment in proliferation, invasion, metastasis, and epithelial–mesenchymal transition (EMT) in vitro and in vivo. Mechanistically, the deregulation of Linc00426 could reduce cytoskeleton rearrangement and matrix metalloproteinase expression. Meanwhile, decreasing the level of Linc00426 or increasing miR-455-5p could down-regulate the level of UBE2V1. Thus, Linc00426 may act as a competing endogenous RNA (ceRNA) to abate miR-455-5p-dependent UBE2V1 reduction. We conclude that Linc00426 accelerates LUAD progression by acting as a molecular sponge to regulate miR-455-5p, and may be a potential novel tumor marker for LUAD.Subject terms: Prognostic markers, Tumour biomarkers     

Syntenin-1-mediated small extracellular vesicles promotes cell growth,migration, and angiogenesis by increasing onco-miRNAs secretion in lung cancer cells

Small extracellular vesicles (sEVs) play a pivotal role in tumor progression by mediating intercellular communication in the tumor microenvironment (TME). Syntenin-1 induces malignant tumor progression in various types of human cancers, including human lung cancer and regulates biogenesis of sEVs. However, the function of syntenin-1-regulated sEVs and miRNAs in sEVs remains to be elucidated. In the present study, we aimed to demonstrate the role of oncogenic Ras/syntenin-1 axis in the release of sEVs and elucidate the function of syntenin-1-mediated miRNAs in sEVs in lung cancer progression. The results revealed that oncogenic Ras promoted the release of sEVs by inducing syntenin-1 expression; disruption of syntenin-1 expression impaired the release of sEVs as well as sEV-mediated cancer cell migration and angiogenesis. Moreover, we identified three miRNAs, namely miR-181a, miR-425-5p, and miR-494-3p, as onco-miRNAs loaded into syntenin-1-dependent sEVs. Remarkably, miR-494-3p was highly abundant in sEVs and its release was triggered by syntenin-1 expression and oncogenic Ras. Ectopic expression of the miR-494-3p mimic enhanced the migration and proliferation of lung cancer cells as well as tube formation in endothelial cells; however, the miR-494-3p inhibitor blocked sEV-mediated effects by targeting tyrosine-protein phosphatase nonreceptor type 12 (PTPN12), a tumor suppressor. sEVs promoted tumor growth and angiogenesis by downregulating PTPN12 expression; however, the miR-494-3p inhibitor significantly suppressed these effects in vivo, confirming that miR-494-3p acts as a major onco-miRNA loaded into lung cancer cell-derived sEVs. Eventually, the oncogenic Ras/syntenin-1 axis may induce cancer progression by increasing miR-494-3p loading into sEVs in lung cancer cells in the TME.Subject terms: Cancer microenvironment, Non-small-cell lung cancer, Oncogenesis     

Downregulation of lysyl oxidase-like 4 LOXL4 by miR-135a-5p promotes lung cancer progression in vitro and in vivo

Aberrant microRNAs are widely identified in multiple cancers, including lung cancer. miR-135a-5p can function as a significant tumor regulator in diverse cancers via impacting multiple genes in oncogenic pathways. Nevertheless, the biological role of miR-135a-5p in lung cancer is poorly known. Here, we investigated its function in lung cancer. As exhibited, miR-135a-5p was elevated in lung cancer cells in contrast to BEAS-2B cells. Then, we inhibited miR-135a-5p expression by transfecting LV-anti-miR-135a-5p into lung cancer cells. As displayed, miR-135a-5p was obviously reduced in A549 and H1299 cells. Knockdown of miR-135a-5p repressed lung cancer cell growth and cell proliferation. Meanwhile, cell colony formation capacity was depressed, cell apoptosis was enhanced and cell cycle progression was blocked in G1 phase by inhibition of miR-135a-5p in vitro. Additionally, the migration and invasion of A549 and H1299 cells was strongly depressed by LV-anti-miR-135a-5p. For another, by using informatics analysis, lysyl oxidase-like 4 (LOXL4) was speculated as the downstream target of miR-135a-5p. We validated their direct correlation and moreover, overexpression of miR-135a-5p restrained LOXL4 levels in lung cancer cells. Subsequently, we proved that miR-135a-5p promoted lung cancer development via targeting LOXL4 by carrying out the in vivo assays. Taken these together, our study revealed miR-135a-5p might be indicated as a perspective for lung cancer via targeting LOXL4.     

MicroRNA-340 suppresses osteosarcoma tumor growth and metastasis by directly targeting ROCK1

MicroRNAs (miRNAs) play key roles in cancer development and progression. In the present study, we investigated the role of miR-340 in the progression and metastasis of osteosarcoma (OS). Our results showed that miR-340 was frequently downregulated in OS tumors and cell lines. Overexpression of miR-340 in OS cell lines significantly inhibited cell proliferation, migration, and invasion in vitro, and tumor growth and metastasis in a xenograft mouse model. ROCK1 was identified as a target of miR-340, and ectopic expression of miR-340 downregulated ROCK1 by direct binding to its 3′ untranslated region. siRNA-mediated silencing of ROCK1 phenocopied the effects of miR-340 overexpression, whereas restoration of ROCK1 in miR-340-overexpressing OS cells reversed the suppressive effects of miR-340. Together, these findings indicate that miR-340 acts as a tumor suppressor and its downregulation in tumor tissues may contribute to the progression and metastasis of OS through a mechanism involving ROCK1, suggesting miR-340 as a potential new diagnostic and therapeutic target for the treatment of OS.     

LncRNA ADAMTS9-AS1 inhibits the stemness of lung adenocarcinoma cells by regulating miR-5009-3p/NPNT axis

We sought to extend our observation of LncRNA ADAMTS9-AS1 and to specifically uncover its role on the stemness of lung adenocarcinoma (LUAD) cancer cells. ADAMTS9-AS1 was poorly expressed in LUAD. The high ADAMTS9-AS1 expression was positively associated with overall survival. ADAMTS9-AS1 overexpression attenuated the colony-forming capacity and reduced stem cell-like population of LUAD cancer stem cells (CSCs). Furthermore, ADAMTS9-AS1 overexpression increased E-cadherin expression in addition to the downregulated expressions of Fibronectin and Vimentin in LUAD spheres. In vitro results also confirmed the ADAMTS9-AS1's inhibitory effect on the growth of LUAD cells. Moreover, the antagonistic repression of miR-5009-3p levels with the expression of ADAMTS9-AS1 and NPNT was confirmed. Finally, ADAMTS9-AS1 overexpression curbed the increasing stemness of LUDA-CSC caused by NPNT silencing, thus leading to the suppression of LUAD progression in vitro. Conclusively, ADAMTS9-AS1 negatively controls the LUAD cancer cell stemness progression through regulating miR-5009-3p/NPNT axis.     

Knockdown of Linc00052 alleviated spinal nerve ligation-triggered neuropathic pain through regulating miR-448 and JAK1

The dysfunction of the nervous system contributes to neuropathic pain. Long noncoding RNAs are reported to participate in neuropathic pain. Recently, Linc00052 is implicated to be closely associated with multiple diseases. Nevertheless, the mechanisms of Linc00052 remain barely explored in neuropathic pain development. Currently, spinal nerve ligation (SNL) triggered neuropathic pain was employed in our investigation. Here, we assessed the function of Linc00052 in SNL rat models. Interestingly, we reported Linc00052 was significantly elevated in SNL rats. Loss of Linc00052 could reduce neuropathic pain progression via regulating the behaviors of neuropathic pain. Additionally, knockdown of Linc00052 repressed the processes of neuroinflammation. Interleukin (IL)-6 and tumor necrosis factor α level were inhibited while IL-10 was induced by the silence of Linc00052. Moreover, we predicted miR-448 can serve as a target of Linc00052. miR-448 exerts a crucial power in several diseases. Currently, we exhibited miR-448 was remarkably downregulated in SNL rats. RNA immunoprecipitation experiments validated the association between miR-448 and Linc00052. Inhibition of Linc00052 could reverse the roles of miR-448 on neuropathic pain development. Furthermore, Janus kinase 1 (JAK1) was displayed as the putative target of miR-448 in the present investigation. It was showed that JAK1 was induced in SNL rats. Loss of miR-448 could dramatically induce the expression of JAK1, which was rescued by knockdown of Linc00052. Taken these together, our study implied that Linc00052 functioned as a novel target of neuropathic pain via sponging miR-448 and regulating JAK1.