LncRNA MALAT1 Promotes Lung Cancer Proliferation and Gefitinib Resistance by Acting as a miR-200a Sponge

Long Non-Coding RNA TRIM52-AS1 Promotes Growth and Metastasis via miR-218-5p/ROBO1 in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is a malignant disease with a high mortality among primary HCC patients worldwide. Lots of studies have shown that lncRNAs are known as the biomarkers in diagnosis, treatment and prognosis of hepatocellular carcinoma. Therefore, clarifying the detailed function and mechanism of the lncRNA in the HCC progressing seems particularly important.

Methods

The TCGA and GEO database and RT-qPCR were used to analyse the expression of TRIM52-AS1 in HCC tissues and cell lines. Clinical data were collected to further analyze the correlation between indicators of clinical samples and the expression of TRIM52-AS1. CCK-8, plate clone and transwell assays were employed to evaluate the role of TRIM52-AS1 on cell proliferation, migration and invasion. Then, bioinformatics prediction, luciferase reporter, RNA immunoprecipitation (RIP), and RT-qPCR were employed to analyze the direct interaction among TRIM52-AS1, miR-218-5p and ROBO1. Additionally, the rescue function assays were used to verify that miR-218-5p/ROBO1 was the function downstream of TRIM52-AS1.

Results

TRIM52-AS1 was overexpressed in HCC according to the TCGA database and RT-qPCR assay. The expression of TRIM52-AS1 was higher in the metastatic foci compared with primary tumor according to the GEO database. Additionally, TRIM52-AS1 knockdown inhibited the proliferation and metastasis of HCC cells. TRIM52-AS1 could act as competitive endogenous RNA to regulate ROBO1 through miR-218-5p, then promoted the HCC cell progression.

Conclusion

TRIM52-AS1 is overexpressed in HCC and can promote the proliferation and metastasis of HCC cells through miR-218-5p/ROBO1 axis, then drives the HCC cell progression.

LncRNA influence sequential steps of hepatocellular carcinoma metastasis

As a class of new and crucial molecules involved in the regulation of biological function, long noncoding RNA (lncRNA) have obtained widespread attention in recent days. While it was thought that lncRNA would be redundant in the past, it is proved that lncRNA identify a class of molecular that regulate the homeostasis including hepatocellular carcinoma in the present. All kinds of lncRNA have been implicated in a various of diseases, particularly in tumorigenesis and metastasis. But the mechanisms how they act is still not entirely clear. Metastasis is a major factor affecting long-term survival in hepatocellular carcinoma (HCC) patients. Recently, growing numbers of experiments demonstrate that there is close connection between lncRNA and HCC metastasis. Here, we will briefly introduce a series of steps (primary tumor growth, angiogenesis, epithelial-to-mesenchymal transition, invasion, intravasation, survival in circulatory system, extravasation, dormancy and subsequent secondary tumor growth) of tumor metastasis, its classical but promising theories, the role of lncRNA in metastasis and the possible mechanisms involved. LncRNA, as potentially new and important tumor diagnostic and therapeutic molecules, has attracted much attention in recent years.

LncRNA MALAT1 facilitates BM-MSCs differentiation into endothelial cells via targeting miR-206/VEGFA axis

Bone marrow-derived mesenchymal stem cells (BM-MSCs) implantation shows a repair effect on erectile function in diabetes mellitus-induced erectile dysfunction (DMED) due to its differentiative capacity into endothelial cells (ECs) that contributes to endothelial repair. This study was designed to explore the functional role and mechanism of long noncoding RNA (lncRNA)-metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in BM-MSCs-mediated DMED repairing. The DMED rat model was established and the erectile function was evaluated by calculating the intracavernous pressure (ICP)/mean arterial pressure (MAP) ratio in the DMED models with or without BM-MSCs implantation. The differentiation of BM-MSCs toward ECs was assessed by measuring the expression of EC-specific genes. RNA pull-down and luciferase reporter assay were performed to explore the interaction between miR-206 and MALAT1 or VEGFA. BM-MSCs implantation improved the erectile function of DMED rats and increased MALAT1 expression. MALAT1 was time-dependently upregulated during the VEGF-induced BM-MSCs differentiation into ECs. Mechanistically, MALAT1 acted as a sponge of miR-206 to upregulate VEGFA expression, thereby promoting the differentiation of BM-MSCs into ECs. Moreover, MALAT1 silencing in vivo impaired the repairing effect of BM-MSCs on erectile dysfunction. Collectively, MALAT1 facilitates BM-MSCs differentiation into ECs via regulating miR-206/VEGFA axis.

[Down-regulation of HOTAIR Reverses the Resistance of Gefitinib in HCC827 Cells by Increasing the Expression of PTEN]

背景与目的

肺癌是发病率和死亡率最高的恶性肿瘤，其中80%以上为非小细胞肺癌。HOX转录反义RNA(HOX transcript antisense RNA, HOTAIR)异常表达于多种肿瘤组织，并参与调控肺癌的发生与发展，本研究旨在探讨下调HOTAIR对肺腺癌HCC827细胞对吉非替尼药物耐药的影响及其机制。

方法

应用实时荧光定量PCR(quantitative real-time PCR, RT-qPCR)法检测HCC827细胞及HCC827吉非替尼耐药细胞(HCC827GR)中HOTAIR的表达情况，利用生物信息学分析预测HOTAIR靶基因，应用脂质体转染法将体外合成的针对HOTAIR的siRNA转染入HCC827GR细胞中，采用RT-qPCR及Western blot方法检测其HOTAIR及PTEN、PI3K、AKT的表达水平，同时采用MTT法检测各组细胞的吉非替尼半数抑制浓度(50% inhibitory concentration, IC₅₀)，运用流式细胞术分析各组细胞凋亡率的变化。

结果

RT-qPCR结果显示HOTAIR在HCC827GR耐药细胞及吉非替尼耐药患者血清中表达增高，利用生物信息学分析预测到PTEN的为HOTAIR潜在靶基因。RT-qPCR及Western blot结果显示HCC827GR细胞经转染HOTAIR siRNA后，HOTAIR表达降低(P < 0.05)，而PTEN表达升高，PI3K及AKT表达下降(P < 0.05)；与对照组比较，下调HOTAIR的HCC827GR细胞对吉非替尼的IC₅₀值下降(P < 0.05)，细胞增殖能力下降、凋亡率升高(P < 0.05)。

结论

下调HOTAIR表达可抑制HCC827GR细胞增殖，促进其凋亡，并可降低HCC827GR细胞的吉非替尼IC₅₀，下调HOTAIR后PTEN表达升高，而PI3K及AKT表达下降提示下调HOTAIR可通过靶向调控PTEN/PI3K/AKT通路逆转HCC827GR细胞对吉非替尼的耐药。

Role of microRNA/Epithelial-to-Mesenchymal Transition Axis in the Metastasis of Bladder Cancer

Bladder cancer (BC) is the 11th most common diagnosed cancer, and a number of factors including environmental and genetic ones participate in BC development. Metastasis of BC cells into neighboring and distant tissues significantly reduces overall survival of patients with this life-threatening disorder. Recently, studies have focused on revealing molecular pathways involved in metastasis of BC cells, and in this review, we focus on microRNAs (miRNAs) and their regulatory effect on epithelial-to-mesenchymal transition (EMT) mechanisms that can regulate metastasis. EMT is a vital process for migration of BC cells, and inhibition of this mechanism restricts invasion of BC cells. MiRNAs are endogenous non-coding RNAs with 19-24 nucleotides capable of regulating different cellular events, and EMT is one of them. In BC cells, miRNAs are able to both induce and/or inhibit EMT. For regulation of EMT, miRNAs affect different molecular pathways such as transforming growth factor-beta (TGF-β), Snail, Slug, ZEB1/2, CD44, NSBP1, which are, discussed in detail this review. Besides, miRNA/EMT axis can also be regulated by upstream mediators such as lncRNAs, circRNAs and targeted by diverse anti-tumor agents. These topics are also discussed here to reveal diverse molecular pathways involved in migration of BC cells and strategies to target them to develop effective therapeutics.

LncRNA HCG11 promotes proliferation and migration in gastric cancer via targeting miR-1276/CTNNB1 and activating Wnt signaling pathway

Background

Gastric cancer (GC) is one common cancer which occurs in the stomach leading to high mortality around the world. Long non-coding RNAs (lncRNAs) were found overexpressed or silenced in the occurrence and progression of multiple cancers including GC.

Method

The gene expression level in GC tissues and cells were analyzed by RT-qPCR. CCK-8, colony formation, flow cytometry and transwell assays were performed for the function analysis of HLA complex group 11 (HCG11). The mechanism study for HCG11 was conducted using RIP, RNA pull down and luciferase reporter assays.

Results

HCG11 was discovered highly expressed in GC tissues and cells. Depletion experiments were used to evaluate HCG11 silence on cell proliferation, migration and apoptosis. Moreover, Wnt signaling pathway was found as a tumor promoter in GC. RIP assay, RNA pull down assay and luciferase reporter assay were performed to illustrate the relationship of HCG11, miR-1276 and CTNNB1. Rescue assays revealed that HCG11/miR-1276/CTNNB1 axis regulated the incidence and development of GC. Tumor formation in mice proved that HCG11 was negatively correlated with miR-1276 and had positively correlation with CTNNB1.

Conclusion

Overall, HCG11 accelerated proliferation and migration in GC through miR-1276/CTNNB1 and Wnt signaling pathway, revealing that HCG11 could be a brand new target for GC.

Long Non-Coding RNA in the Pathogenesis of Cancers

The incidence and mortality rate of cancer has been quickly increasing in the past decades. At present, cancer has become the leading cause of death worldwide. Most of the cancers cannot be effectively diagnosed at the early stage. Although there are multiple therapeutic treatments, including surgery, radiotherapy, chemotherapy, and targeted drugs, their effectiveness is still limited. The overall survival rate of malignant cancers is still low. It is necessary to further study the mechanisms for malignant cancers, and explore new biomarkers and targets that are more sensitive and effective for early diagnosis, treatment, and prognosis of cancers than traditional biomarkers and methods. Long non-coding RNAs (lncRNAs) are a class of RNA transcripts with a length greater than 200 nucleotides. Generally, lncRNAs are not capable of encoding proteins or peptides. LncRNAs exert diverse biological functions by regulating gene expressions and functions at transcriptional, translational, and post-translational levels. In the past decade, it has been demonstrated that the dysregulated lncRNA profile is widely involved in the pathogenesis of many diseases, including cancer, metabolic disorders, and cardiovascular diseases. In particular, lncRNAs have been revealed to play an important role in tumor growth and metastasis. Many lncRNAs have been shown to be potential biomarkers and targets for the diagnosis and treatment of cancers. This review aims to briefly discuss the latest findings regarding the roles and mechanisms of some important lncRNAs in the pathogenesis of certain malignant cancers, including lung, breast, liver, and colorectal cancers, as well as hematological malignancies and neuroblastoma.