LINC00473 antagonizes the tumour suppressor miR‐195 to mediate the pathogenesis of Wilms tumour via IKKα

Objectives

Although dramatic improvements of overall survival has achieved in patients with favourable histology Wilms tumour, disease recurrence is still the main cause of cancer‐related death in childhood. Long non‐coding RNAs (lncRNAs) as oncogenes or tumour suppressors are dysregulated during carcinogenesis. However, the role of lncRNAs in the pathogenesis of Wilms tumour is unknown. Here, an lncRNA LINC00473 signature that functioned as oncogene was identified in Wilms tumour.

Methods

Wilms tumour (n = 15) and relative normal tissues were collected. The LINC00473 expression and function in Wilms tumour was determined. The LncRNA‐miRNA network of LINC00473 was analysed in vitro and vivo.

Results

We uncovered that the expression of LINC00473 was elevated in tumour tissues than that in relative normal tissues. Higher LINC00473 levels correlated to higher stage and unfavourable histology Wilms tumour. Mechanistically, knockdown of LINC00473 inhibited cell vitality and induced Bcl‐2‐dependent apoptosis and G1/S arrest via CDK2 and cyclin D1. Moreover, LINC00473 harboured binding sites for miR‐195 and limited miR‐195 availability in a dose‐dependent manner. Forced expression of miR‐195 impaired tumour survival and metastasis, which, however, could be restored by LINC00473. Furthermore, IKKα was the downstream of LINC00473/miR‐195 signals and could be directly targeted by miR‐195 to participate LINC00473‐induced tumour progression. Loss‐of‐function of LINC00473 in vivo effectively promoted the regression of Wilms tumour via miR‐195/IKKα‐mediated growth inhibition.

Conclusion

LINC00473 as an oncogene is up‐regulated to participate into the molecular pathogenesis of Wilms tumour via miR‐195/IKKα.     

TGFβ mediated LINC00273 upregulation sponges mir200a-3p and promotes invasion and metastasis by activating ZEB1

Transforming growth factor β (TGFβ) is a prominent cytokine that promotes tumor progression by activating epithelial-to-mesenchymal transition (EMT). This study indicated that TGFβ exerted metastasis by inducing zinc finger E-box binding homeobox 1 (ZEB1) and a long noncoding RNA, LINC00273, expressions in A549 cells. Knocking down LINC00273 diminished TGFβ induced ZEB1 expression as well as metastasis. Mechanistically, LINC00273 acted as a molecular sponge of microRNA (miR)-200a-3p which liberate ZEB1 to perform its prometastatic functions. LINC00273 knockdown and miR200a3p mimic transfection of A549 cells were used for validating the link between TGFβ and LINC00273 induced metastasis. RNA pulldown and luciferase assay were performed to establish mir200a-3p-LINC00273 interaction. High expressions of LINC00273, TGFβ, and ZEB1 with concurrent low miR200a-3p expression had been verified in vivo and in patient samples. Overall, LINC00273 promoted TGFβ-induced lung cancer EMT through miR-200a-3p/ZEB1 feedback loop and may serve as a potential target for therapeutic intervention in lung cancer metastasis.     

Long intergenic noncoding RNA 00641 inhibits breast cancer cell proliferation,migration, and invasion by sponging miR-194-5p

Long noncoding RNAs have an essential role in the tumorigenesis of breast cancer (BC). Nonetheless, the consequences of long intergenic noncoding RNA 00641 (LINC00641) in BC remain unidentified. This study shows that LINC00641 expression level was decreased in BC tissues. LINC00641 expression level was negatively related to tumor size, lymph-node metastasis, as well as clinical stage. LINC00641 overexpression inhibited cell proliferation, migration, and invasion but stimulated apoptosis in BC cells. LINC00641 overexpression also remarkably reduced BC growth and metastasis in vivo. LINC00641 acts as a competitive endogenous RNA to sponge miR-194-5p. miR-194-5p level was higher in BC tissues and cells compared with normal-adjacent tissues and normal breast epithelial cell. miR-194-5p expression was negatively correlated with LINC00641 expression in BC tissues. miR-194-5p overexpression reversed the effects of LINC00641 on cell proliferation, cycle, apoptosis, migration, as well as invasion. In conclusion, LINC00641 inhibits BC cell proliferation, migration, as well as invasion by sponging miR-194-5p.     

Silencing of lncRNA UCA1 curbs proliferation and accelerates apoptosis by repressing SIRT1 signals by targeting miR‐204 in pediatric AML

The long noncoding RNA urothelial carcinoma‐associated 1 (UCA1) has been reported to sustain the proliferation of acute myeloid leukemia (AML) cells through downregulating cell cycle regulators p27^kip1. Yet, the foundational mechanism of UCA1 in AML pathologies remains unclear. Herein, we found an escalation of UCA1 expression and suppression of miR‐204 expression in pediatric AML patients and cells. UCA1 silencing suppressed cell proliferative abilities, promoted apoptotic rates, decreased Ki67, and increased cleaved caspase‐3 in AML cells. Moreover, UCA1 sponged miR‐204 and suppressed its expression. UCA1 overexpression inversed the miR‐204 suppressed proliferation and promoted apoptosis. UCA1 also boosted the expression of SIRT1, a miR‐204 target, via the sponging interaction. Furthermore, miR‐204 inhibited inducible nitric oxide synthase and cyclooxygenase‐2 expression, while UCA1 overexpression inversed the inhibitory effects in AML cells. Our findings concluded that UCA1 downregulation repressed cell proliferation and promoted apoptosis through inactivating SIRT1 signals by upregulating miR‐204 in pediatric AML.     

RNA methylation-mediated LINC01559 suppresses colorectal cancer progression by regulating the miR-106b-5p/PTEN axis

Long noncoding RNAs (lncRNAs) regulate multiple biological effects in cancers. Recently, RNA methylation has been found to modify not only coding RNAs but also some noncoding RNAs. How RNA methylation affects lncRNAs to affect colorectal cancer (CRC) progression remains elusive. The expression of LINC01559 was explored through RNA sequencing, quantitative real-time PCR (qRT-PCR) and in situ hybridization (ISH). The preliminary exploration of its function was performed using Western blotting (WB) and immunohistochemistry (IHC). Functional experiments in vitro and in vivo were conducted to explore the biological functions of LINC01559 in CRC. The LINC01559/miR-106-5p/PTEN axis was verified through fluorescence in situ hybridization (FISH), luciferase assays, and rescue experiments. RIP-sequencing, m6A RNA immunoprecipitation (MeRIP) assays and bioinformatic analysis were conducted to determine the upstream mechanism of LINC01559. The results showed that LINC01559 was downregulated in CRC compared with normal controls. Lower expression of LINC01559 in CRC patients predicted a poor prognosis. In addition, PTEN was found to be positively correlated with LINC01559, and miR-106b-5p could be the link between LINC01559 and PTEN. Then, silencing LINC01559 restored the malignant phenotype of CRC cells, while cotransfection of miR-106b-5p inhibitor neutralized this effect. Mechanistically, we found abundant m6A modification sites on LINC01559. Then, we uncovered these sites as potential targets of METTL3 through experiments in vivo. The results revealed a negative functional regulation of the LINC01559/miR-106b-5p/PTEN axis in CRC progression and explored a new mechanism of METTL3-mediated m6A modification on LINC01559. These results elucidate a novel potential therapeutic target for CRC treatment.     

SIRT2, a direct target of miR‐212‐5p,suppresses the proliferation and metastasis of colorectal cancer cells

The aberrant expression of human sirtuin 2 (SIRT2) has been detected in various types of cancer; however, the biological roles, underlying mechanisms and clinical significance of SIRT2 dysregulation in human colorectal cancer (CRC) remain unclear. The results of this study demonstrate that compared with paired normal tissues, SIRT2 expression is significantly decreased in CRC tissues. SIRT2 loss has been correlated with clinicopathological characteristics, including distant metastasis, lymph node metastasis and American Joint Committee on Cancer (AJCC) stage; this loss serves as an independent factor that indicates a poor prognosis for patients with CRC. Further gain‐ and loss‐of‐function analyses have demonstrated that SIRT2 suppresses CRC cell proliferation and metastasis both in vivo and in vitro. Mechanistically, miR‐212‐5p was identified to directly target the SIRT2 3′‐untranslated region (3′‐UTR), leading to SIRT2 down‐regulation. The ectopic expression of SIRT2 reverses the effect of miR‐212‐5p overexpression on CRC cell colony formation, invasion, migration and proliferation. Clinically, an inverse correlation was found between miR‐212‐5p and SIRT2 expression. High miR‐212‐5p expression has been found to result in a poor prognosis and aggressive clinicopathological characteristics in patients with CRC. Taken together, these results suggest that SIRT2, targeted by miR‐212‐5p, acts as a tumour suppressor in CRC and that the miR‐212‐5p/SIRT2 axis is a promising prognostic factor and potential therapeutic target in CRC.     

MicroRNA‐301b‐3p contributes to tumour growth of human hepatocellular carcinoma by repressing vestigial like family member 4

MicroRNAs (miRNAs) are key regulators in the tumour growth and metastasis of human hepatocellular carcinoma (HCC). Increasing evidence suggests that miR‐301b‐3p functions as a driver in various types of human cancer. However, the expression pattern of miR‐301b‐3p and its functional role as well as underlying molecular mechanism in HCC remain poorly known. Our study found that miR‐301b‐3p expression was significantly up‐regulated in HCC tissues compared to adjacent non‐tumour tissues. Clinical association analysis revealed that the high level of miR‐301b‐3p closely correlated with large tumour size and advanced tumour‐node‐metastasis stages. Importantly, the high miR‐301b‐3p level predicted a prominent poorer overall survival of HCC patients. Knockdown of miR‐301b‐3p suppressed cell proliferation, led to cell cycle arrest at G2/M phase and induced apoptosis of Huh7 and Hep3B cells. Furthermore, miR‐301b‐3p knockdown suppressed tumour growth of HCC in mice. Mechanistically, miR‐301b‐3p directly bond to 3′UTR of vestigial like family member 4 (VGLL4) and negatively regulated its expression. The expression of VGLL4 mRNA was down‐regulated and inversely correlated with miR‐301b‐3p level in HCC tissues. Notably, VGLL4 knockdown markedly repressed cell proliferation, resulted in G2/M phase arrest and promoted apoptosis of HCC cells. Accordingly, VGLL4 silencing rescued miR‐301b‐3p knockdown attenuated HCC cell proliferation, cell cycle progression and apoptosis resistance. Collectively, our results suggest that miR‐301b‐3p is highly expressed in HCC. miR‐301b‐3p facilitates cell proliferation, promotes cell cycle progression and inhibits apoptosis of HCC cells by repressing VGLL4.     

Long noncoding RNA HNF1A‐AS1 regulates proliferation and apoptosis of glioma through activation of the JNK signaling pathway via miR‐363‐3p/MAP2K4

Long noncoding RNAs (lncRNAs) have been proven to exert important functions in the various biological processes of human cancers. It has been reported that lncRNA HNF1 homeobox A antisense RNA 1 (HNF1A‐AS1) was abnormally expressed and played a role in the initiation and development of various human cancers. In this study, we confirmed that the expression level of HNF1A‐AS1 was increased in glioma tissues and cells. Knockdown of HNF1A‐AS1 inhibited cell proliferation and promoted cell apoptosis in glioma. Then, we disclosed the downregulation of miR‐363‐3p in glioma tissues and cell lines. The interaction between HNF1A‐AS1 and miR‐363‐3p was identified in glioma cells. Furthermore, an inverse correlation between HNF1A‐AS1 and miR‐363‐3p was observed in glioma tissues. Afterwards, we recognized that MAP2K4 was a direct target of miR‐363‐3p. The expression of MAP2K4 was negatively correlated with miR‐363‐3p while positively related to HNF1A‐AS1 in glioma tissues. We also found the regulatory effect of HNF1A‐AS1 on the MAP2K4‐dependent JNK signaling pathway. All findings indicated that HNF1A‐AS1 induces the upregulation of MAP2K4 to activate the JNK signaling pathway to promote glioma cell growth by acting as a miR‐363‐3p sponge.     

LINC01101 and LINC00277 expression levels as novel factors in HPV‐induced cervical neoplasia

Recently long non‐coding RNAs were identified as new factors involved in gene expression regulation. To gain insight into expression pattern of these factors related to E7 HPV18 oncogene, this study uses HeLa cell culture transfected with E7‐siRNA. Gene expression profile was investigated using microarray analysis. After analysing the microarray results, we identified 15,387 RNA species differentially expressed in E7‐siRNA‐transfected cells compared with controls (fold change >2). The expression profiles of lncRNA species highlighted 731 lncRNAs and 203 lincRNAs. We selected two lincRNAs (LINC01101 and LINC00277) and we evaluated the expression profile in HPV‐induced neoplasia. Both lincRNAs investigated display a significantly reduced pattern of expression in cervical lesions and cancer, associated with clinical parameters. A connection between HPV presence and lincRNAs was noted. hrHPV‐positive samples exhibit significantly reduced LINC01101 and LINC00277 expression level (P < 0.05). These results provide new insights into involvement of lncRNA in HPV‐induced cervical cancer, enriching our understanding of their potential role in this pathology.     

Knockdown of LINC01614 inhibits lung adenocarcinoma cell progression by up‐regulating miR‐217 and down‐regulating FOXP1

We tried to identify the function of LINC01614 in lung adenocarcinoma (LUAD) and reveal its underlying mechanisms. qRT‐PCR was applied to assess the expression of LINC016014 in LUAD tissues, noncancerous tissues and cells. Through colony formation assay, MTT assay and apoptosis analysis, we examined the variation of cell proliferation and apoptosis ability after silencing LINC01614. Moreover, the targeting interactions among LINC01614, miR‐217 and FOXP1 were validated via luciferase reporter assay, and then, we regulated the expression of miR‐217 and FOXP1 to ascertain their importance in cell proliferation and apoptosis. LINC01614 and FOXP1 were found to be up‐regulated in LUAD tumours and cells, whereas miR‐217 was down‐regulated. The experiment showed that target‐specific selectivity exists between LINC01614‐miR‐217 and miR‐217‐FOXP1 3′UTR. Furthermore, we disclosed that inhibition of LINC01614 could activate miR‐217, which subsequently restrained FOXP1. It was proved that LINC01614 promoted FOXP1 by inhibiting miR‐217, which ultimately stimulated the development of LUAD.     

LncRNA HOXA11‐AS regulates calcium oxalate crystal–induced renal inflammation via miR‐124‐3p/MCP‐1

Long noncoding RNA (lncRNA) has been suggested to play an important role in a variety of diseases over the past decade. In a previous study, we identified a novel lncRNA, termed HOXA11‐AS, which was significantly up‐regulated in calcium oxalate (CaOx) nephrolithiasis. However, the biological function of HOXA11‐AS in CaOx nephrolithiasis remains poorly defined. Here, we demonstrated that HOXA11‐AS was significantly up‐regulated in CaOx nephrolithiasis both in vivo and in vitro. Gain‐/loss‐of‐function studies revealed that HOXA11‐AS inhibited proliferation, promoted apoptosis and aggravated cellular damage in HK‐2 cells exposed to calcium oxalate monohydrate (COM). Further investigations showed that HOXA11‐AS regulated monocyte chemotactic protein 1 (MCP‐1) expression in HK‐2 cell model of CaOx nephrolithiasis. In addition, online bioinformatics analysis and dual‐luciferase reporter assay results showed that miR‐124‐3p directly bound to HOXA11‐AS and the 3'UTR of MCP‐1. Furthermore, rescue experiment results revealed that HOXA11‐AS functioned as a competing endogenous RNA to regulate MCP‐1 expression through sponging miR‐124‐3p and that overexpression of miR‐124‐3p restored the inhibitory effect of proliferation, promotion effects of apoptosis and cell damage induced by HOXA11‐AS overexpression. Taken together, HOXA11‐AS mediated CaOx crystal–induced renal inflammation via the miR‐124‐3p/MCP‐1 axis, and this outcome may provide a good potential therapeutic target for nephrolithiasis.     

Long non‐coding RNA SNHG16 promotes proliferation and inhibits apoptosis of diffuse large B‐cell lymphoma cells by targeting miR‐497‐5p/PIM1 axis

The aberrant expression and dysfunction of long non‐coding RNAs (lncRNAs) have been identified as critical factors governing the initiation and progression of different human cancers, including diffuse large B‐cell lymphoma (DLBCL). LncRNA small nucleolar RNA host gene 16 (SNHG16) has been recognized as a tumour‐promoting factor in various types of cancer. However, the biological role of SNHG16 and its underlying mechanism are still unknown in DLBCL. Here we disclosed that SNHG16 was overexpressed in DLBCL tissues and the derived cell lines. SNHG16 knockdown significantly suppressed cell proliferation and cell cycle progression, and it induced apoptosis of DLBCL cells in vitro. Furthermore, silencing of SNHG16 markedly repressed in vivo growth of OCI‐LY7 cells. Mechanistically, SNHG16 directly interacted with miR‐497‐5p by acting as a competing endogenous RNA (ceRNA) and inversely regulated the abundance of miR‐497‐5p in DLBCL cells. Moreover, the proto‐oncogene proviral integration site for Moloney murine leukaemia virus 1 (PIM1) was identified as a novel direct target of miR‐497‐5p. SNHG16 overexpression rescued miR‐497‐5p‐induced down‐regulation of PIM1 in DLBCL cells. Importantly, restoration of PIM1 expression reversed SNHG16 knockdown‐induced inhibition of proliferation, G0/G1 phase arrest and apoptosis of OCI‐LY7 cells. Our study suggests that the SNHG16/miR‐497‐5p/PIM1 axis may provide promising therapeutic targets for DLBCL progression.     

MiR‐30‐5p suppresses cell chemoresistance and stemness in colorectal cancer through USP22/Wnt/β‐catenin signaling axis

Colorectal cancer (CRC) remains both common and fatal, and its successful treatment is greatly limited by the development of stem cell‐like characteristics (stemness) and chemoresistance. MiR‐30‐5p has been shown to function as a tumor suppressor by targeting the Wnt/β‐catenin signaling pathway, but its activity in CRC has never been assessed. We hypothesized that miR‐30‐5p exerts anti‐oncogenic effects in CRC by regulating the USP22/Wnt/β‐catenin signaling axis. In the present study, we demonstrate that tissues from CRC patients and human CRC cell lines show significantly decreased miR‐30‐5p family expression. After identifying the 3’UTR of USP22 as a potential binding site of miR‐30‐5p, we constructed a luciferase reporter containing the potential miR‐30‐5p binding site and measured the effects on USP22 expression. Western blot assays showed that miR‐30‐5p decreased USP22 protein expression in HEK293 and Caco2 CRC cells. To evaluate the effects of miR‐30‐5p on CRC cell stemness, we isolated CD133 + CRC cells (Caco2 and HCT15). We then determined that, while miR‐30‐5p is normally decreased in CD133 + CRC cells, miR‐30‐5p overexpression significantly reduces expression of stem cell markers CD133 and Sox2, sphere formation, and cell proliferation. Similarly, we found that miR‐30‐5p expression is normally reduced in 5‐fluorouracil (5‐FU) resistant CRC cells, whereas miR‐30‐5p overexpression in 5‐FU resistant cells reduces sphere formation and cell viability. Inhibition of miR‐30‐5p reversed the process. Finally, we determined that miR‐30‐5p attenuates the expression of Wnt/β‐catenin signaling target genes (Axin2 and MYC), Wnt luciferase activity, and β‐catenin protein levels in CRC stem cells.