Knockdown of Long Non-coding RNA HOTAIR Suppresses Tumor Invasion and Reverses Epithelial-mesenchymal Transition in Gastric Cancer

Background: Over-expression of long non-coding RNA HOTAIR has been reported in several types of cancer. Yet its involvement in gastric cancer (GC) has not been well understood. The aim of present study was to examine the expression pattern of HOTAIR in GC patients, then, explore its role in promoting cancer invasion and underlying molecular mechanism. Methods: The expression level of HOTAIR in the tumor specimens of GC patients was quantified by Realtime RT-PCR. The correlation between HOTAIR level and clinicopathological factors as well as prognosis was then examined. Down-regulation of HOTAIR by RNA interference was applied to investigate its roles in tumor invasiveness via the view of Epithelial-to-mesenchymal transition (EMT). Results: The expression level of HOTAIR in cancer tissues was higher than that in adjacent noncancerous tissues. Expression level of HOTAIR was significantly correlated with lymph node metastasis and TNM stage. Furthermore, high expression level of HOTAIR was a predictor of poor over-all survival in GC patients. In vitro, inhibition of HOTAIR in GC cells could reduce invasiveness, as well as the expression of MMP1 and MMP3. In addition, suppression of HOTAIR could reverse EMT process. Conclusions: HOTAIR could act as a potential predictor for over-all survival in patients with GC. Inhibition of HOTAIR could reduce invasiveness and reverse EMT process in GC cells, indicating the potential role of HOTAIR in GC diagnostics and therapeutics.     

Enhanced Expression of Long Non-Coding RNA HOTAIR Is Associated with the Development of Gastric Cancer

The long non-coding RNA HOTAIR has been reported to be a poor prognostic biomarker in a variety of malignant tumors. However, little is known about the association of HOTAIR with gastric cancer. We examined the expression of HOTAIR in 68 gastric cancer samples using quantitative real-time RT-PCR and analyzed its correlation with the clinical parameters. The functional role of HOTAIR was examined by generating human gastric cancer cell lines with increased or suppressed HOTAIR expression. The anchorage -independent growth was assessed by soft agar assay. The increased or suppressed HOTAIR expressing gastric cancer cells were injected into the tail vein or peritoneal cavity of immunodeficient mice to examine the effect of this molecule on metastasis and peritoneal dissemination. The expression of HOTAIR was significantly higher in cancer lesions than in adjacent non-cancerous tissues in human gastric cancers. In the diffuse type of gastric cancer, the High-HOTAIR group (HOTAIR/GAPDH > 1) showed significantly more venous invasion, frequent lymph node metastases and a lower overall survival rate compared to the Low-HOTAIR group (HOTAIR/GAPDH < 1). Colony formation on the soft agar was enhanced in a HOTAIR-dependent manner. HOTAIR-expressing MKN74 formed more liver metastasis compared to control when they were injected into the tail vein of mice. In addition, reduced expression of HOTAIR in KATO III suppressed peritoneal dissemination. These results suggest that HOTAIR plays a pivotal role in the development of gastric cancer.     

Cav-1通过增加IncRNA HOTAIR的表达促进非小细胞肺癌细胞增殖

目的:探讨Cav-1对非小细胞肺癌(NSCLC)细胞增殖的影响及其分子机制。方法:取我院收治的2017年1月至2018年1月15例NSCLC患者手术切除的肺组织,并获取肺癌旁组织15例。实时定量PCR检测其中Cav-1和lncRNA HOTAIR的表达。进一步检测Cav-1和lncRNA HOTAIR在各肺癌细胞系中的表达。采用脂质体3000介导将si CAV-1和pcDNA3.1/CAV-1转染入NSCLC细胞系中,实时定量PCR检测lncRNA HOTAIR的表达,CCK-8检测细胞增殖。随后,将si HOTAIR以及pcDNA3.1/HOTAIR转染入CAV-1过表达的NSCLC细胞系中,CCK-8检测细胞增殖情况。结果:NSCLC患者手术切除的肺组织中CAV-1m RNA和HOTAIR lncRNA的表达均显著高于其在癌旁组织(P0.001)。与健康人肺组织上皮细胞系(NuLi-1)相比,各肺癌细胞系中CAV-1 m RNA和HOTAIR lncRNA的表达均显著增加,鳞状细胞癌细胞系(SK-MES-1)除外。si CAV-1显著降低NSCLC中CAV-1的表达(P0.01)以及其增殖能力,而pcDNA3.1/CAV-1显著增加NSCLC中CAV-1的表达(P0.01)以及其增殖。与对照si RNA相比,si CAV-1显著降低HOTAIR lncRNA的表达(P 0.05)。与对照质粒相比,pcDNA3.1/CAV-1显著增加HOTAIR lncRNA的表达(P0.01)。si HOTAIR可显著抑制NSCLC细胞增殖(P0.05),且可明显取消pcDNA3.1/CAV-1转染对NSCLC细胞增殖的促进作用(P0.05),而pcDNA3.1/HOTAIR可显著增加NSCLC细胞增殖(P0.05),且CAV-1过表达可增强pcDNA3.1/HOTAIR对NSCLC细胞增殖的促进作用(P0.05),而si CAV-1转染可抑制pcDNA3.1/HOTAIR对NSCLC细胞增殖的促进作用。结论:CAV-1通过上调lncRNA HOTAIR的表达促进肺癌细胞的增殖。     

HOTAIR/miR-326/FUT6 axis facilitates colorectal cancer progression through regulating fucosylation of CD44 via PI3K/AKT/mTOR pathway

Metastasis is the main cause of death in colorectal cancer (CRC) patients. Aberrant fucosylation, catalyzed by the specific fucosyltransferases (FUTs), is associated with malignant behaviors. Non-conding RNAs, including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), emerge as key molecules in cancer malignancy. The aim of this study was to investigate HOTAIR/miR-326/FUT6 axis modified fucosylation on sLe^X-CD44 (HCELL), which served as E-selectin ligand during CRC progression. Higher levels of HOTAIR and FUT6 were verified in CRC tissues and cell lines, with a positive correlation. HOTAIR was associated with poor clinical prognosis of CRC. Altered HOTAIR levels influenced proliferation, aggressiveness, apoptosis and tumorigenesis of CRC cells. HOTAIR directly harbored miR-326 binding sites and regulated FUT6 expression. Further results corroborated that HOTAIR/miR-326/FUT6 axis modified α1, 3-fucosylation of CD44, which mediated CRC malignancy. Co-modulation of HOTAIR, miR-326 and FUT6 impacted α1, 3-fucosylated CD44, which further triggered PI3K/AKT/mTOR pathway. HOTAIR also mediated CRC tumorigenesis and liver metastasis in vivo. Thus, our findings indicated that HOTAIR/miR-326/FUT6 axis mediated CRC procession through α1, 3-fucosylated CD44 via PI3K/AKT/mTOR pathway. This work rendered new therapeutic targets for CRC.     

Long non-coding RNA Linc00152 is involved in cell cycle arrest,apoptosis, epithelial to mesenchymal transition,cell migration and invasion in gastric cancer

Gastric cancer remains a serious threat to public health with high incidence and mortality worldwide. Accumulating evidence demonstrates that long non-coding RNAs (lncRNAs) play important roles in regulating gene expression and are involved in various pathological processes, including gastric cancer. To investigate the possible role of dysregulated lncRNAs in gastric cancer development, we performed lncRNA microarray and identified 3141 significantly differentially expressed lncRNAs in gastric cancer tissues. Next, some of deregulated lncRNAs were validated among about 60 paired gastric cancer specimens such as Linc00261, DKFZP434K028, RPL34-AS1, H19, HOTAIR and Linc00152. Our results found that the decline of DKFZP434K028 and RPL34-AS1, and the increased expression of Linc00152 positively correlated with larger tumor size. The high expression levels of HOTAIR were associated with lymphatic metastasis and poor differentiation. Since the biological roles of Linc00152 are largely unknown in gastric cancer pathogenesis, we assessed its functions by silencing its up-regulation in gastric cancer cells. We found that Linc00152 knockdown could inhibit cell proliferation and colony formation, promote cell cycle arrest at G1 phase, trigger late apoptosis, reduce the epithelial to mesenchymal transition (EMT) program, and suppress cell migration and invasion. Taken together, we delineate the gastric cancer lncRNA signature and demonstrate the oncogenic functions of Linc00152. These findings may have implications for developing lncRNA-based biomarkers for diagnosis and therapeutics for gastric cancer.     

Down‐regulated lncRNA HOTAIR alleviates polycystic ovaries syndrome in rats by reducing expression of insulin‐like growth factor 1 via microRNA‐130a

It has been found that long noncoding RNA HOTAIR, microRNA‐130a (miR‐130a) and insulin‐like growth factor 1 (IGF1) expression are associated with ovarian cancer, thus, we hypothesised that the HOTAIR/miR‐130a/IGF1 axis might associate with endocrine disorders and biological behaviours of ovarian granulosa cells in rat models of polycystic ovary syndrome (PCOS). PCOS rat models were established by injection of dehydro‐isoandrosterone, followed by treatment of si‐HOTAIR, oe‐HOTAIR, miR‐130a mimics or miR‐130a inhibitors. Serum hormonal levels were determined to evaluate endocrine conditions. The effect of HOTAIR and miR‐130a on activities of isolated ovarian granulosa cells was assessed, as well as the involvement of IGF1.In the ovarian tissues and granulosa cells of PCOS rat models, highly expressed HOTAIR and IGF1 and poorly expressed miR‐130a were identified. In response to oe‐HOTAIR, serum levels of E₂, T and LH were increased and serum levels of FSH were reduced; the proliferation of granulosa cells was reduced and apoptosis was promoted; notably, expression of miR‐130a was reduced while expression of IGF1 was increased. The treatment of si‐HOTAIR reversed the situation. Furthermore, the binding of HOTAIR to miR‐130a and targeting relationship of miR‐130a and IGF1 were confirmed. LncRNA HOTAIR up‐regulates the expression of IGF1 and aggravates the endocrine disorders and granulosa cell apoptosis through competitive binding to miR‐130a in rat models of PCOS. Based on our finding, we predict that competitive binding of HOTAIR to miR‐130a may act as a novel target for the molecular treatment of PCOS.     

Dampening HOTAIR sensitizes the gastric cancer cells to oxaliplatin through miR-195-5p and ABCG2 pathway

Long non-coding RNAs (lncRNA) have an extensive role in the progression and chemoresistance of gastric cancer (GC). Deeply study the regulatory role of lncRNAs could provide potential therapeutic targets. The aim of this study is to explore the regulatory role of HOTAIR in the progression and oxaliplatin resistance of GC. The expression of HOTAIR in GC and cell lines were detected by using qRT-PCR. Cell proliferation and apoptosis were analysed by CCK-8, EdU incorporation and flow cytometry. Luciferase reporter assay was used to identify the interaction between HOTAIR and ABCG2 (ATP-binding cassette (ABC) superfamily G member 2, ABCG2) via miR-195-5p. The regulatory functions were verified by using molecular biology experiments. HOTAIR was significantly overexpressed in GC and associated with poor prognosis. Knock-down of HOTAIR inhibited the GC cells proliferation and oxaliplatin resistance, while overexpression of HOTAIR showed opposite functions. Further studies found that HOTAIR acted as a competing endogenous RNA (ceRNA) to absorb miR-195-5p and elevated the expression of ABCG2, which leads to resistance of GC cells to oxaliplatin. Taken together, our findings demonstrated that HOTAIR regulates ABCG2 induced resistance of GC to oxaliplatin through miR-195-5p signalling and illustrate the great potential of developing new therapeutic targets for GC patients.