The lncRNA TP73‐AS1 promotes ovarian cancer cell proliferation and metastasis via modulation of MMP2 and MMP9

Ovarian cancer is one of the most common gynecologic malignancy with poor prognosis. Recently, long noncoding RNAs (lncRNAs) have been identified as key regulators in cancer development. The current study investigated the role of lncRNA P73 antisense RNA 1T (TP73‐AS1) in ovarian cancer. Quantitative real‐time polymerase chain reaction determined the expression levels of TP‐73AS1, matrix metallopeptidases (MMPs) messenger RNA. Cell proliferative ability, cell invasion, and migration were CCK‐8 and colony formation, and transwell invasion and migration assays, respectively. The protein levels of matrix metallopeptidase 2 (MMP2) and MMP9 were measured by Western blot. TP73‐AS1 was upregulated in the ovarian cancer tissues and ovarian cancer cells, and upregulation of TP73‐AS1 was associated with poor prognosis. Knockdown of TP73‐AS1 significantly suppressed cell proliferation, invasion, and migration of SKOV3 cells, and overexpression of TP73‐AS1 promoted cell proliferation, invasion, and migration of OVCA429 cells. In addition, knockdown of TP73‐AS1 suppressed the in vivo tumor growth. Tumor metastasis RT² profiler polymerase chain reaction array showed that MMP2 and MMP9 was significantly upregulated by TP73‐AS1 overexpression in ovarian cancer cells. TP73‐AS1 overexpression enhanced the expression of MMP2 and MMP9 in ovarian cancer cells. Knockdown of MMP2 and MMP9 attenuated the effects of TP73‐AS1 overexpression on cell invasion and migration. The clinical data showed that MMP2 and MMP9 were upregulated and positively correlated with TP73‐AS1 expression in ovarian cancer tissues. Collectively, our results demonstrated the oncogenic role of TP73‐AS1 in ovarian cancer, and targeting TP73‐AS1 may represent a novel approach in battling against ovarian cancer.     

LncRNA WDFY3‐AS2 suppresses proliferation and invasion in oesophageal squamous cell carcinoma by regulating miR‐2355‐5p/SOCS2 axis

Long non‐coding RNAs (lncRNAs) widely participate in ESCC development and progression; however, the prognostic factors and therapeutic strategies implicated in ESCC development and progression remain to be under investigation. The purpose of the current study was to explore whether WDFY3‐AS2 may be a potential prognostic factor and investigate its biological functions in ESCC. Here, WDFY3‐AS2 was frequently down‐regulated in ESCC tissues and cells, and its expression was correlated with TNM stage, lymph node metastasis and poor prognosis of ESCC patients. Moreover, WDFY3‐AS2 down‐regulation significantly promoted cell proliferation and invasion, whereas WDFY3‐AS2 up‐regulation markedly suppressed cell proliferation and invasion in ESCC EC9706 and TE1 cells, coupled with EMT phenotype alterations. WDFY3‐AS2 functioned as a competing endogenous RNA (ceRNA) for sponging miR‐2355‐5p, further resulted in the up‐regulation of its target gene SOCS2, followed by suppression of JAK2/Stat5 signalling pathway, to suppress ESCC cell proliferation and invasion in EC9706 and TE1 cells. These findings suggest that WDFY3‐AS2 may participate in ESCC development and progression, and may be a novel prognostic factor for ESCC patients, and thus targeting WDFY3‐AS2/miR‐2355‐5p/SOCS2 signalling axis may be a novel therapeutic strategy for ESCC patients.     

Long non‐coding RNA FEZF1‐AS1 promotes breast cancer stemness and tumorigenesis via targeting miR‐30a/Nanog axis

Long non‐coding RNAs (lncRNAs) have been verified to modulate the tumorigenesis of breast cancer at multiple levels. In present study, we aim to investigate the role of lncRNA FEZF1‐AS1 on breast cancer‐stem like cells (BCSC) and the potential regulatory mechanism. In breast cancer tissue, lncRNA FEZF1‐AS1 was up‐regulated compared with controls and indicated poor prognosis of breast cancer patients. In vitro experiments, FEZF1‐AS1 was significantly over‐expressed in breast cancer cells, especially in sphere subpopulation compared with parental subpopulation. Loss‐of‐functional indicated that, in BCSC cells (MDA‐MB‐231 CSC, MCF‐7 CSC), FEZF1‐AS1 knockdown reduced the CD44⁺/CD24^? rate, the mammosphere‐forming ability, stem factors (Nanog, Oct4, SOX2), and inhibited the proliferation, migration and invasion. In vivo, FEZF1‐AS1 knockdown inhibited the breast cancer cells growth. Bioinformatics analysis tools and series of validation experiments confirmed that FEZF1‐AS1 modulated BCSC and Nanog expression through sponging miR‐30a, suggesting the regulation of FEZF1‐AS1/miR‐30a/Nanog. In summary, our study validate the important role of FEZF1‐AS1/miR‐30a/Nanog in breast cancer stemness and tumorigenesis, providing a novel insight and treatment strategy for breast cancer.     

LncRNA NR2F2‐AS1 promotes tumourigenesis through modulating BMI1 expression by targeting miR‐320b in non‐small cell lung cancer

Recently, long noncoding RNAs (lncRNAs) are attracting wide attention in the field of cancer research because of its important role in cancer diagnosis and prognosis. But studies on the biological effects and relevant mechanisms of lncRNAs in non‐small cell lung cancer (NSCLC) remain few and need to be enriched. Our study discussed the expression and biological effects of LncRNA NR2F2‐AS1, and further explored its possible molecular mechanisms. As a result, elevated expression of NR2F2‐AS1 was detected in NSCLC tissues and cells and was remarkably associated with the tumor, node, metastasis (TNM) stage and the status of lymphatic metastasis of patients. Down‐regulated NR2F2‐AS1 contributed to the promotion of cell apoptosis and the inhibition of cell proliferation and invasion in A549 and SPC‐A‐1 cells in vivo and vitro. Through bioinformatics analysis, NR2F2‐AS1 functions as a ceRNA directly binding to miR‐320b, BMI1 was a direct target of miR‐320b. Combined with the following cellular experiments, the data showed that NR2F2‐AS1 may influence the NSCLC cell proliferation, invasion and apoptosis through regulating miR‐320b targeting BMI1.     

LncRNA ADAMTS9‐AS2 suppresses the proliferation of gastric cancer cells and the tumorigenicity of cancer stem cells through regulating SPOP

Nowadays, research on CSCs is still in an initial stage, and there are few studies reporting the successful isolation and identification of CSCs. In the present study, we attempted to isolate CSCs through cultivating the cell line MKN45 in defined serum‐free medium and study the expression of stem cell markers or related proteins (Oct3/4, Sox2, Nanog and CD44) in CSCs. Moreover, immunofluorescence staining was performed to validate the stem cell markers of spheroid body‐forming cells. Further experiments were used to evaluate the SPOP expression in tumorsphere cells. In addition, ADAMTS9‐AS2 is a lncRNA that contributes to the genesis and development of many cancers, including gastric cancer (GC). We found ADAMTS9‐AS2 functioned as an anti‐oncogene and positively correlated with the expression of SPOP in GC tissues by combining bioinformatics analyses. Furthermore, we reported that ADAMTS9‐AS2 regulated the expression of SPOP in GC cells and tumorsphere cells to inhibit GC progression. Together, our results demonstrated that SPOP and ADAMTS9‐AS2 can be potential targets for GC treatment.     

LncRNA MALAT1/miR‐129 axis promotes glioma tumorigenesis by targeting SOX2

We aimed to explore the interaction among lncRNA MALAT1, miR‐129 and SOX2. Besides, we would investigate the effect of MALAT1 on the proliferation of glioma stem cells and glioma tumorigenesis. Differentially expressed lncRNAs in glioma cells and glioma stem cells were screened out with microarray analysis. The targeting relationship between miR‐129 and MALAT1 or SOX2 was validated by dual‐luciferase reporter assay. The expressions of MALAT1, miR‐129 and SOX2mRNA in both glioma non‐stem cells and glioma stem cells were examined by qRT‐PCR assay. The impact of MALAT1 and miR‐129 on glioma stem cell proliferation was observed by CCK‐8 assay, EdU assay and sphere formation assay. The protein expression of SOX2 was determined by western blot. The effects of MALAT1 and miR‐129 on glioma tumour growth were further confirmed using xenograft mouse model. The mRNA expression of MALAT1 was significantly up‐regulated in glioma stem cells compared with non‐stem cells, while miR‐129 was significantly down‐regulated in glioma stem cells. MALAT1 knockdown inhibited glioma stem cell proliferation via miR‐129 enhancement. Meanwhile, miR‐129 directly targeted at SOX2 and suppressed cell viability and proliferation of glioma stem cells by suppressing SOX2 expression. The down‐regulation of MALAT1 and miR‐129 overexpression both suppressed glioma tumour growth via SOX2 expression promotion in vivo. MALAT1 enhanced glioma stem cell viability and proliferation abilities and promoted glioma tumorigenesis through suppressing miR‐129 and facilitating SOX2 expressions.     

LncRNA BDNF‐AS inhibits proliferation,migration, invasion and EMT in oesophageal cancer cells by targeting miR‐214

This study was aimed at exploring the effect of lncRNA BDNF‐AS on cell proliferation, migration, invasion and epithelial‐to‐mesenchymal transition (EMT) of oesophageal cancer (EC) cells. The expression of BDNF‐AS and miR‐214 in tissue samples and cells was measured by qRT‐PCR. The targeted relationship between BDNF‐AS and miR‐214 was analysed by dual‐luciferase reporter assay. After cell transfection, the cell proliferation activity was assessed by MTS method, while the migrating and invading abilities were evaluated by transwell assay. LncRNA BDNF‐AS was remarkably down‐regulated, while miR‐214 was up‐regulated in EC tissues and cells in comparison with normal tissues and cells. Overexpression of BDNF‐AS significantly inhibited the abilities of cell proliferation, migration and invasion as well as the EMT processes of EC cells. The bioinformatics analysis and luciferase assay indicated that BDNF‐AS could be directly bound by miR‐214. Furthermore, overexpression of miR‐214 and BDNF‐AS exerted suppressive influence on EC cell multiplication, migration, invasion and EMT processes. LncRNA BDNF‐AS restrained cell proliferation, migration, invasion and EMT processes in EC cells by targeting miR‐214.     

TP73‐AS1 promotes breast cancer cell proliferation through miR‐200a‐mediated TFAM inhibition

P73 antisense RNA 1T (TP73‐AS1 or PDAM) is a long non‐coding RNA, which can regulate apoptosis through regulation of p53 signaling‐related anti‐apoptotic genes. An abnormal change of TP73‐AS1 expression was noticed in cancers. The effects of TP73‐AS1 in breast cancer (BC) growth and the underlying mechanism remain unclear so far. In the present study, the effect of TP73‐AS1 in BC cell lines and clinical tumor samples was detected so as to reveal its role and function. In the present study, TP73‐AS1 was specifically upregulated in BC tissues and BC cell lines and was correlated to a poorer prognosis in patients with BC. TP73‐AS1 knocking down suppressed human BC cell proliferation in vitro through regulation of TFAM. In our previous study, we demonstrated that miR‐200a inhibits BC cell proliferation through targeting TFAM; here we revealed that TP73‐AS1 could regulate miR‐200a through direct targeting. Moreover, TP73‐AS1 might compete with TFAM for miR‐200a binding thus to promote TFAM expression. Data from the present study revealed that TP73‐AS1 promoted BC cell proliferation through acting as a competing endogenous RNA (ceRNA) by sponging miR‐200a. In conclusion, we regarded TP73‐AS1 as an oncogenic lncRNA promoting BC cell proliferation and a potential target for human BC treatment.     

LncRNA HOXA11‐AS promotes hepatocellular carcinoma progression by repressing miR‐214‐3p

Accumulating studies supported that lncRNAs played important roles in tumorigenesis. LncRNA HOXA11‐AS was a novel lncRNA that has been proved to involved in several tumours. However, the role of HOXA11‐AS in the development of hepatocellular carcinoma (HCC) remains to be explained. In our study, we showed that HOXA11‐AS expression was up‐regulated in the HCC tissues, and the higher expression of HOXA11‐AS was associated with the advanced stage in the HCC samples. In addition, we indicated that the expression of HOXA11‐AS was up‐regulated in HCC cell lines (Hep3B, SMMC‐7721, MHCC97‐H and BEL‐7402) compared with normal liver cell lines (HL‐7702). Overexpression of HOXA11‐AS promoted HCC proliferation and invasion and induced the epithelial‐mesenchymal transition (EMT) and knockdown of HOXA11‐AS suppressed the HCC cell proliferation and invasion. However, we showed that miR‐214‐3p expression was down‐regulated in the HCC tissues and cell lines. Ectopic expression of miR‐214‐3p suppressed HCC cell proliferation and invasion. Furthermore, we indicated that overexpression of HOXA11‐AS decreased the miR‐214‐3p expression and the expression of miR‐214‐3p was negatively related with the HOXA11‐AS expression in HCC samples. Ectopic expression of HOXA11‐AS increased HCC proliferation and invasion and induced EMT through inhibiting miR‐214‐3p expression. These data suggested that HOXA11‐AS/miR‐214‐3p axis was responsible for development of HCC.     

LncRNA TNK2‐AS1 regulated ox‐LDL‐stimulated HASMC proliferation and migration via modulating VEGFA and FGF1 expression by sponging miR‐150‐5p

Long non‐coding RNAs (lncRNAs) have been indicated for the regulatory roles in cardiovascular diseases. This study determined the expression of lncRNA TNK2 antisense RNA 1 (TNK2‐AS1) in oxidized low‐density lipoprotein (ox‐LDL)‐stimulated human aortic smooth muscle cells (HASMCs) and examined the mechanistic role of TNK2‐AS1 in the proliferation and migration of HASMCs. Our results demonstrated that ox‐LDL promoted HASMC proliferation and migration, and the enhanced proliferation and migration in ox‐LDL‐treated HASMCs were accompanied by the up‐regulation of TNK2‐AS1. In vitro functional studies showed that TNK2‐AS1 knockdown suppressed cell proliferation and migration of ox‐LDL‐stimulated HASMCs, while TNK2‐AS1 overexpression enhanced HASMC proliferation and migration. Additionally, TNK2‐AS1 inversely regulated miR‐150‐5p expression via acting as a competing endogenous RNA (ceRNA), and the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by miR‐150‐5p overexpression. Moreover, miR‐150‐5p could target the 3’ untranslated regions of vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 1 (FGF1) to regulate FGF1 and VEGFA expression in HASMCs, and the inhibitory effects of miR‐150‐5p overexpression in ox‐LDL‐stimulated HASMCs were attenuated by enforced expression of VEGFA and FGF1. Enforced expression of VEGFA and FGF1 also partially restored the suppressed cell proliferation and migration induced by TNK2‐AS1 knockdown in ox‐LDL‐stimulated HASMCs, while the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by the knockdown of VEGFA and FGF1. Collectively, our findings showed that TNK2‐AS1 exerted its action in ox‐LDL‐stimulated HASMCs via regulating VEGFA and FGF1 expression by acting as a ceRNA for miR‐150‐5p.     

LncRNA MST1P2/miR‐133b axis affects the chemoresistance of bladder cancer to cisplatin‐based therapy via Sirt1/p53 signaling

Although bladder cancer is commonly chemosensitive to standard first‐line therapy, the acquisition of the resistance to cisplatin (DDP)‐based therapeutic regimens remains a huge challenge. Noncoding RNAs (ncRNAs), including long noncoding RNAs (lncRNAs) and microRNAs, have been reported to play a critical role in cancer resistance to DDP. Here, we attempted to provide a novel mechanism by which the resistance of bladder cancer to DDP treatment could be modulated from the perspective of ncRNA regulation. We demonstrated that lncRNA MST1P2 (lnc‐MST1P2) expression was dramatically upregulated, whereas miR‐133b expression was downregulated in DDP‐resistant bladder cancer cell lines, SW 780/DDP and RT4/DDP. Lnc‐MST1P2 and miR‐133b negatively regulated each other via targeting miR‐133b. Both lnc‐MST1P2 silence and miR‐133b overexpression could resensitize DDP‐resistant bladder cancer cells to DDP treatment. More important, miR‐133b could directly target the Sirt1 3′‐untranslated region to inhibit its expression. Inc‐MST1P2/miR‐133b axis affected the resistance of bladder cancer cells to DDP via Sirt1/p53 signaling. In conclusion, MST1P2 serves as a competing endogenous RNA for miR‐133b to counteract miR‐133b‐induced suppression on Sirt1, therefore enhancing the resistance of bladder cancer cells to DDP. MST1P2/miR‐133b axis affects the resistance of bladder cancer cells to DDP via downstream Sirt1/p53 signaling.