Long Noncoding RNA HOTAIR Promotes Endometrial Carcinoma Cell Proliferation by Binding to PTEN via the Activating Phosphatidylinositol 3-Kinase/Akt Signaling Pathway

The Promotive and Inhibitory Role of Long Non-Coding RNAs in Endometrial Cancer Course-A Review

Endometrial cancer is one of the most common malignant tumours in women. The development of this tumour is associated with several genetic disorders, many of which are still unknown. One type of RNA molecules currently being intensively studied in many types of cancer are long non-coding RNAs (lncRNAs). LncRNA-coding genes occupy a large fraction of the human genome. LncRNAs regulate many aspects of cell development, metabolism, and other physiological processes. Diverse types of lncRNA can function as a tumour suppressor or an oncogene that can alter migration, invasion, cell proliferation, apoptosis, and immune system response. Recent studies suggest that selected lncRNAs are important in an endometrial cancer course. Our article describes over 70 lncRNAs involved in the development of endometrial cancer, which were studied via in vivo and in vitro research. It was proved that lncRNAs could both promote and inhibit the development of endometrial cancer. In the future, lncRNAs may become an important therapeutic target. The aim of this study is to review the role of lncRNAs in the development of carcinoma of uterine body.

Emerging roles of HOTAIR lncRNA in the pathogenesis and prognosis of cardiovascular diseases

Highlights HOTAIR, a long noncoding RNA, plays a role in the regulation of proteins involved in the pathogenesis of cardiovascular disease. Furthermore, it has been identified as a biomarker of this type of disease. Several factors and cells contribute to atherosclerosis, a progressive disease. However, the prognosis of HOTAIR in this disease varies depending on the path in which it plays a role. For this condition, there is no single prognosis to consider.

Estrogen promotes the proliferation and migration of endometrial cancer cells by upregulating the expression of lncRNA HOTAIR

OBJECTIVE

Estrogen (E2) is the main contributor to the progression of endometrial cancer (EC). The long noncoding RNA HOX antisense intergenic RNA (HOTAIR) is emerging as a new regulator in several cancer types. This study aimed to investigate the role of HOTAIR in EC development and identify the underlying molecular mechanisms.

METHODS

HOTAIR expression levels in human EC tissues and the corresponding adjacent tissues and human EC Ishikawa cells were determined by quantitative PCR. Ishikawa cells were treated with E2 or estrogen receptor (ER) inhibitor ICI182780, transfected with siHOTAIR oligo, or infected with lentivirus expressing shHOTAIR/shNC, alone or in combinations. The protein expression of polycomb repressive complex 2 (PRC2) was evaluated by western blotting, and cell migration was measured by transwell assays. A xenograft tumorigenic model was established by inoculating control or stable shHOTAIR-infected Ishikawa cells into nude mice and implanting 17β-estradiol release pellets.

RESULTS

HOTAIR expression was significantly elevated in human EC tissues. E2 exposure markedly increased HOTAIR levels in Ishikawa cells. Notably, E2 increased the protein expression of PRC2 and promoted EC cell migration, which were dependent on HOTAIR expression, as HOTAIR knockdown abolished these effects of E2. Similarly, E2 promoted the in vivo proliferation of grafted Ishikawa cells via upregulated HOTAIR expression in nude mice.

CONCLUSIONS

Human EC tissues highly express HOTAIR, and E2-induced EC progression depends on HOTAIR expression. This work suggests that the E2-HOTAIR axis is a potential therapeutic target in EC therapy.

Nanocarrier-based targeting of metabolic pathways for endometrial cancer: Status and future perspectives

Cancer is the second-most lethal global disease, as per health reports, and is responsible for around 70% of deaths in low- and middle-income countries. Endometrial cancer is one of the emerging malignancies and has been predicted as a public health challenge for the future. Insulin resistance, obesity, and diabetes mellitus are the key metabolic factors that promote risks for the development of endometrial cancer. Various signaling pathways and associated genes are involved in the genesis of endometrial cancer, and any mutation or deletion in such related factors leads to the induction of endometrial cancer. The conventional way of drug delivery has been used for ages but is associated with poor management of cancer due to non-targeting of the endometrial cancer cells, low efficacy of the therapy, and toxicity issues as well. In this context, nanocarrier-based therapy for the management of endometrial cancer is an effective alternate choice that overcomes the problems associated with conventional therapy. In this review article, we highlighted the nanocarrier-based targeting of endometrial cancer, with a special focus on targeting various metabolic signaling pathways. Furthermore, the future perspectives of nanocarrier-based targeting of metabolic pathways in endometrial cancer were also underpinned. It is concluded that targeting metabolic signaling pathways in endometrial cancer via nanocarrier scaffolds is the future of pharmaceutical design for the significant management and treatment of endometrial cancer.

Downregulated lncRNA HOTAIR ameliorates polycystic ovaries syndrome via IGF-1 mediated PI3K/Akt pathway

OBJECTIVE

Polycystic ovarian syndrome (PCOS) is a common disorder that leads to infertility in reproductive-aged females. HOTAIR is highly expressed in various gynecological diseases and is associated with a poor prognosis. We aimed to explore the role of HOTAIR in PCOS.

METHODS

First, PCOS rats were induced using dehydroepiandrosterone and then treated with si-HOTAIR. Next, HOTAIR mRNA expression and serum hormone levels were detected. HE staining was applied to observe estrus cycle, ovarian morphology and count the number of follicles. Apoptosis in the ovary was detected by TUNEL. Thereafter, ovarian granulosa cells (GCs) were isolated from PCOS rats, transfected with si-HOTAIR and treated with LY294002 (Akt inhibitor) or IGF-1. CCK-8 and flow cytometry assays were used to evaluate cell viability and apoptosis. IGF-1, apoptosis- and PI3K/Akt pathway-associated protein expressions in ovary and GCs were also detected.

RESULTS

In in vivo experiments, si-HOTAIR decreased serum T, E₂ and LH levels but increased FSH level, restored estrus cycle, ovarian morphology and inhibited apoptosis of ovary in PCOS rats. Meanwhile, in vitro assays showed that si-HOTAIR upregulated the viability but inhibited the apoptosis of PCOS GCs. Furthermore, both in vivo and in vitro assays revealed that si-HOTAIR increased Bcl-2 expression but suppressed Bax, Bad, IGF-1 expressions and PI3K, AKT phosphorylation. However, the aforementioned effects of si-HOTAIR in vitro were further enhanced by LY294002 and partially reversed by IGF-1.

CONCLUSIONS

HOTAIR knockdown improved PCOS, and the mechanism may relate to IGF-1-mediated PI3K/Akt pathway, indicating HOTAIR may be a novel therapeutic target for PCOS.

Role of Vitamin K in Bone and Muscle Metabolism

Vitamin K, a cofactor for the γ-glutamyl carboxylase enzyme, is required for the post-translational activation of osteocalcin and matrix Gla protein, which play a key role in bone and muscle homeostasis. In vivo and in vitro models for osteoporosis and sarcopenia suggest the vitamin K could exert a positive effect in both conditions. In bone, it increases osteoblastogenesis, whilst decreases osteoclast formation and function. In muscle, it is associated with increased satellite cell proliferation and migration and might play a role in energy metabolism. Observational trials suggest that high levels of vitamin K are associated with increased bone mineral density and reduced fracture risk. However, interventional studies for vitamin K supplementation yielded conflicting results. Clinical trials in sarcopenia suggest that vitamin K supplementation could improve muscle mass and function. One of the main limitations on the vitamin K studies are the technical challenges to measure its levels in serum. Thus, they are obtained from indirect sources like food questionnaires, or levels of undercarboxylated proteins, which can be affected by other environmental or biological processes. Although current research appoints to a beneficial effect of vitamin K in bone and muscle, further studies overcoming the current limitations are required in order to incorporate this supplementation in the clinical management of patients with osteosarcopenia.

Correlation analysis of differentially expressed long non-coding RNA HOTAIR with PTEN/PI3K/AKT pathway and inflammation in patients with osteoarthritis and the effect of baicalin intervention

OBJECTIVE

This study aims to investigate the correlation of long non-coding RNA HOX transcript antisense RNA (lncRNA HOTAIR) with the PTEN/PI3K/AKT pathway and clinical-related indicators in osteoarthritis (OA) and determine the effect of baicalin intervention.

METHODS

The levels of clinical lipid metabolism indexes and immune-inflammatory indexes in OA patients and normal controls was detected. OA chondrocytes (OA-CHs) were induced with peripheral blood mononuclear cells (PBMCs), followed by baicalin treatment (50 ug/mL). RT-qPCR was performed to measure lncRNA HOTAIR expression. The levels of inflammatory cytokines and adiponectin were detected using ELISA kits. CCK-8 assay was used to assess the viability of CHs. The related protein expression was measured using Western blot analysis.

RESULTS

LncRNA HOTAIR might act as a biomarker of OA in vivo. LncRNA HOTAIR was positively correlated with TC, hs-CRP, IgA, TNF-α, and VAS score. Overexpression of lncRNA HOTAIR in vitro inhibited cell proliferation, reduced IL-10 and PTEN expression, but augmented TNF-α, p-PI3K, and p-AKT proteins in OA-CHs stimulated by OA-PBMCs. The changes of above indexes were also observed in OA-CHs stimulated by OA-PBMCs treated with si-lncRNA HOTAIR or baicalin, implying the synergistic effects of baicalin and lncRNA HOTAIR silencing on OA.

CONCLUSIONS

Conclusively, lncRNA HOTAIR was highly expressed in OA-CHs, which facilitated OA inflammatory responses by orchestrating inflammatory cytokines and the PTEN/PI3K/AKT pathway. Baicalin exerted therapeutic effects by inhibiting the expression of lncRNA HOTAIR, decreasing the protein levels of p-PI3K and p-AKT, and increasing the protein levels of PTEN, APN, and ADIPOR1.

Non-coding RNA and autophagy: Finding novel ways to improve the diagnostic management of bladder cancer

Major fraction of the human genome is transcribed in to the RNA but is not translated in to any specific functional protein. These transcribed but not translated RNA molecules are called as non-coding RNA (ncRNA). There are thousands of different non-coding RNAs present inside the cells, each regulating different cellular pathway/pathways. Over the last few decades non-coding RNAs have been found to be involved in various diseases including cancer. Non-coding RNAs are reported to function both as tumor enhancer and/or tumor suppressor in almost each type of cancer. Urothelial carcinoma of the urinary bladder is the second most common urogenital malignancy in the world. Over the last few decades, non-coding RNAs were demonstrated to be linked with bladder cancer progression by modulating different signalling pathways and cellular processes such as autophagy, metastasis, drug resistance and tumor proliferation. Due to the heterogeneity of bladder cancer cells more in-depth molecular characterization is needed to identify new diagnostic and treatment options. This review emphasizes the current findings on non-coding RNAs and their relationship with various oncological processes such as autophagy, and their applicability to the pathophysiology of bladder cancer. This may offer an understanding of evolving non-coding RNA-targeted diagnostic tools and new therapeutic approaches for bladder cancer management in the future.

Contribution of Non-Coding RNAs to Anticancer Effects of Dietary Polyphenols: Chlorogenic Acid, Curcumin, Epigallocatechin-3-Gallate, Genistein, Quercetin and Resveratrol

Growing evidence has been accumulated to show the anticancer effects of daily consumption of polyphenols. These dietary polyphenols include chlorogenic acid, curcumin, epigallocatechin-3-O-gallate, genistein, quercetin, and resveratrol. These polyphenols have similar chemical and biological properties in that they can act as antioxidants and exert the anticancer effects via cell signaling pathways involving their reactive oxygen species (ROS)-scavenging activity. These polyphenols may also act as pro-oxidants under certain conditions, especially at high concentrations. Epigenetic modifications, including dysregulation of noncoding RNAs (ncRNAs) such as microRNAs, long noncoding RNAs, and circular RNAs are now known to be involved in the anticancer effects of polyphenols. These polyphenols can modulate the expression/activity of the component molecules in ROS-scavenger-triggered anticancer pathways (RSTAPs) by increasing the expression of tumor-suppressive ncRNAs and decreasing the expression of oncogenic ncRNAs in general. Multiple ncRNAs are similarly modulated by multiple polyphenols. Many of the targets of ncRNAs affected by these polyphenols are components of RSTAPs. Therefore, ncRNA modulation may enhance the anticancer effects of polyphenols via RSTAPs in an additive or synergistic manner, although other mechanisms may be operating as well.

HOTAIR interacts with PRC2 complex regulating the regional preadipocyte transcriptome and human fat distribution

Mechanisms governing regional human adipose tissue (AT) development remain undefined. Here, we show that the long non-coding RNA HOTAIR (HOX transcript antisense RNA) is exclusively expressed in gluteofemoral AT, where it is essential for adipocyte development. We find that HOTAIR interacts with polycomb repressive complex 2 (PRC2) and we identify core HOTAIR-PRC2 target genes involved in adipocyte lineage determination. Repression of target genes coincides with PRC2 promoter occupancy and H3K27 trimethylation. HOTAIR is also involved in modifying the gluteal adipocyte transcriptome through alternative splicing. Gluteal-specific expression of HOTAIR is maintained by defined regions of open chromatin across the HOTAIR promoter. HOTAIR expression levels can be modified by hormonal (estrogen, glucocorticoids) and genetic variation (rs1443512 is a HOTAIR eQTL associated with reduced gynoid fat mass). These data identify HOTAIR as a dynamic regulator of the gluteal adipocyte transcriptome and epigenome with functional importance for human regional AT development.

The Emerging role of EMT-related lncRNAs in therapy resistance and their application as biomarkers

Cancer is the world's second largest cause of death. The most common cancer treatments are surgery, radiation therapy, and chemotherapy. Drug resistance, epithelial-to-mesenchymal transition (EMT), and metastasis are all pressing issues in cancer therapy today. Increasing evidence showed that drug-resistant and EMT are co-related with each other. Indeed, drug-resistant cancer cells possess enhanced EMT and invasive ability. Recent researches have demonstrated lncRNAs (long noncoding RNAs) are noncoding transcripts, which play an important role in the regulation of EMT, metastasis, and drug resistance in different cancers. However, the relationships among lncRNAs, EMT, and drug resistance are still unclear. These effects could be exerted via several signaling pathways such as TGF-β, PI3K-AKT, and Wnt/β-catenin. Identifying the crucial regulatory roles of lncRNAs in these pathways and processes leads to the development of novel targeted therapies. We review the key aspects of lncRNAs associated with EMT and therapy resistance. We focus on the crosstalk between lncRNAs and molecular signaling pathways affecting EMT and drug resistance. Moreover, each of the mentioned lncRNAs could be used as a potential diagnostic, prognostic, and therapeutic biomarker for cancer. Although, there are still many challenges to investigate lncRNAs for clinical applications.

The Role of Long Non-Coding RNAs (lncRNAs) in Female Oriented Cancers

Recent advances in molecular biology have discovered the mysterious role of long non-coding RNAs (lncRNAs) as potential biomarkers for cancer diagnosis and targets for advanced cancer therapy. Studies have shown that lncRNAs take part in the incidence and development of cancers in humans. However, previously they were considered as mere RNA noise or transcription byproducts lacking any biological function. In this article, we present a summary of the progress on ascertaining the biological functions of five lncRNAs (HOTAIR, NEAT1, H19, MALAT1, and MEG3) in female-oriented cancers, including breast and gynecological cancers, with the perspective of carcinogenesis, cancer proliferation, and metastasis. We provide the current state of knowledge from the past five years of the literature to discuss the clinical importance of such lncRNAs as therapeutic targets or early diagnostic biomarkers. We reviewed the consequences, either oncogenic or tumor-suppressing features, of their aberrant expression in female-oriented cancers. We tried to explain the established mechanism by which they regulate cancer proliferation and metastasis by competing with miRNAs and other mechanisms involved via regulating genes and signaling pathways. In addition, we revealed the association between stated lncRNAs and chemo-resistance or radio-resistance and their potential clinical applications and future perspectives.

Towards Personalized Medicine: Non-Coding RNAs and Endometrial Cancer

Endometrial cancer (EC) is the most frequent female cancer associated with excellent prognosis if diagnosed at an early stage. The risk factors on which clinical staging is based are constantly updated and genetic and epigenetic characteristics have recently been emerging as prognostic markers. The evidence shows that non-coding RNAs (ncRNAs) play a fundamental role in various biological processes associated with the pathogenesis of EC and many of them also have a prognosis prediction function, of remarkable importance in defining the therapeutic and surveillance path of EC patients. Personalized medicine focuses on the continuous updating of risk factors that are identifiable early during the EC staging to tailor treatments to patients. This review aims to show a summary of the current classification systems and to encourage the integration of various risk factors, introducing the prognostic role of non-coding RNAs, to avoid aggressive therapies where not necessary and to treat and strictly monitor subjects at greater risk of relapse.

LINC00470 Stimulates Methylation of PTEN to Facilitate the Progression of Endometrial Cancer by Recruiting DNMT3a Through MYC

OBJECTIVES

Increasing researches emphasize the importance of long non-coding RNAs (lncRNAs) in the development of endometrial cancer (EC). There is wide recognition that LINC00470 is a critical participant in the tumorigenesis of cancers such as gastric cancer and glioblastoma, but its possible effects on EC progression remain to be explored.

METHODS

We collected EC tissues and cells, where the expression of LINC00470 was determined, and followed by the Kaplan-Meier analysis of EC patient survival. We next examined the effect of LINC00470 and phosphatase and tensin homolog (PTEN) on EC cell migration, invasion, tube formation in vitro, and angiogenesis in mice xenografted with tumor after gain- or loss-of-function treatments. RNA pull-down, Co-IP, and ChIP experiments were performed to analyze the targeting relationships among LINC00470, MYC and DNMT3a.

RESULTS

LINC00470 was aberrantly upregulated in EC and its high expression correlated to prognosis of EC patients. LINC00470 promoted invasiveness, migration, and angiogenesis of EC cells, and facilitated tumorigenesis and metastasis in vivo, but those effects were reversed by up-regulating PTEN. Functionally, LINC00470 bound to MYC in EC and that LINC00470 stimulated the binding of MYC to DNMT3a, and thus recruited DNMT3a through MYC to promote PTEN methylation.

CONCLUSIONS

Our findings revealed that LINC00470 stimulated PTEN methylation to inhibit its expression by MYC-induced recruitment of DNMT3a, thus aggravating EC.

LINC00665 activates Wnt/β-catenin signaling pathway to facilitate tumor progression of colorectal cancer via upregulating CTNNB1

Background LINC00665 is a newly identified oncogene, which has been reported to be oncogene in various cancers. Nevertheless, its role in the progression of colorectal cancer (CRC) remains obscure to the extent. This study aimed at exploring the role and mechanism of LINC00665 in CRC progression. Materials and methods RNA and protein expression were detected via qRT-PCR and western blot. Functional assays were conducted to investigate the role of LINC00665 in the CRC cellular processes. TOP/FOP assay was performed to detect the activity of Wnt/β-catenin signaling pathway. Mechanism investigations were carried out to explore the regulatory relationship among genes. Results LINC00665 was overtly expressed in CRC cell lines at high levels. Functionally, silencing of LINC00665 could curb in vitro CRC cell growth, migration and invasion, while stimulating cell apoptosis. Mechanically, LINC00665 sponged miR-214-3p to up-regulate CTNNB1 expression, consequently activating Wnt/β-catenin signaling pathway. Furthermore, LINC00665 could bind to U2AF2 and enhance the association between U2AF2 and CTNNB1, increasing the stability of CTNNB1. CTNNB1 overexpression could reverse the suppressive effects of LINC00665 downregulation. Conclusion LINC00665 stimulates CRC progression through the activation of Wnt/β-catenin signaling pathway, which hopefully might be a therapeutic target for CRC.

Vitamin K in CKD Bone Disorders

Vitamin K is principally known because it is involved in blood coagulation. Furthermore, epidemiological studies showed that its deficit was associated with increased fragility fractures, vascular calcification and mortality. There are two main types of vitamin K vitamers: Phylloquinone (or PK) and Menaquinones (MKn). Vitamin K acts both as coenzyme of y-glutamyl carboxylase (GGCX) transforming undercarboxylated in carboxylated vitamin K-dependent proteins (e.g., Osteocalcin and Matrix Gla Protein) and as a ligand of the nuclear steroid and xenobiotic receptor (SXR) (in murine species Pregnane X Receptor: PXR), expressed in osteoblasts. It has been highlighted that the uremic state is a condition of greater vitamin K deficiency than the general population with resulting higher prevalence of bone fractures, vascular calcifications and mortality. The purpose of this literature review is to evaluate the protective role of Vitamin K in bone health in CKD patients.

Matrine regulates H2O2-induced oxidative stress through long non-coding RNA HOTAIR/miR-106b-5p axis via AKT and STAT3 pathways

Matrine is a main active constituent of Chinese herb Sophora flavescens Ait (Kushen), which has shown various pharmacological effects, and has been reported to exhibit protective effects in heart failure. In the present study, the underlying mechanism of matrine was explored in H₂O₂-induced H9c2 cell line. It was confirmed that matrine could alleviate H₂O₂-induced injury in H9c2 cells. And the down-regulation of long non-coding RNA HOTAIR induced by H₂O₂ could be reversed by treating with matrine. Moreover, overexpression of HOTAIR promoted cell viability and superoxide dismutase (SOD) level, but inhibited cell apoptosis and lactate dehydrogenase (LDH) level. We found that miR-106b-5p was a target of HOTAIR and negatively regulated by HOTAIR. Moreover, up-regulation of miR-106b-5p restored the effects of HOTAIR overexpression on cell viability, apoptosis, and the levels of LDH and SOD. In addition, matrine protected H9c2 cells from H₂O₂-induced injury through HOTAIR/miR-106b-5p axis. Furthermore, we discovered that matrine exerted protective effects on H₂O₂-induced H9c2 cells through activating STAT3 and AKT pathway. In brief, matrine modulated H₂O₂-induced myocardial oxidative stress repair through HOTAIR/miR-106b-5p axis via AKT and STAT3 signaling pathway. Our study may provide a therapeutic target for the therapy of oxidative stress heart diseases.

Non-Coding RNAs as Prognostic Markers for Endometrial Cancer

Endometrial cancer (EC) has been classified over the years, for prognostic and therapeutic purposes. In recent years, classification systems have been emerging not only based on EC clinical and pathological characteristics but also on its genetic and epigenetic features. Noncoding RNAs (ncRNAs) are emerging as promising markers in several cancer types, including EC, for which their prognostic value is currently under investigation and will likely integrate the present prognostic tools based on protein coding genes. This review aims to underline the importance of the genetic and epigenetic events in the EC tumorigenesis, by expounding upon the prognostic role of ncRNAs.

HOX transcript antisense RNA: An oncogenic lncRNA in diverse malignancies

HOX transcript antisense RNA (HOTAIR) is a transcript produced from the antisense strand of the HOXC gene cluster and influencing expression of genes from the HOXD locus. HOTAIR has prominent roles in different aspects of carcinogenic process from cancer initiation to metastasis. A number of in vitro, in vivo and human investigations have confirmed the oncogenic impacts of HOTAIR. The diagnostic power of HOTAIR in distinguishing cancer status from healthy status has been optimal in gastric cancer, pancreatic adenocarcinoma and colorectal cancer. The most important achievement in this regard has been provided by studies that verified diagnostic value of this lncRNA in the serum samples, potentiating its application in non-invasive diagnosis of cancer. Moreover, HOTAIR has a crucial role in determination of response of cancer cells to therapeutic modalities. The current review aims to explain the outlines of these studies to emphasize its potential as a biomarker and therapeutic target for these conditions.

[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。

Inhibition of Lnc-OC1 Induced Cell Apoptosis and Decreased Cell Viability by Releasing miR-34a and Inhibiting PD-L1 in Endometrial Carcinoma

Now, there is a growing awareness of the role to long non-coding RNAs (lncRNAs) in tumorigenesis and progression of a variety of malignancies including endometrial carcinoma (EC). Here, we explored the potential molecular mechanism of Lnc-OC1, a novel lncRNA, in the development of EC. Our results suggested that Lnc-OC1 was significantly upregulated in EC tissues comparing with normal tissues. Besides, Lnc-OC1 was higher expressed in the more advanced stage of EC. Therefore, Lnc-OC1 might be a crucial regulator in the progress of EC. Moreover, knockdown of Lnc-OC1 leaded to an inhibition of cell viability and a raise of cell apoptosis. In addition, Lnc-OC1 could sponge miR-34a and thus decrease its expression. miR-34a was proved to be a tumor suppressor in different malignance, hence downregulating Lnc-OC1 helped to alleviate EC by releasing miR-34a. Furthermore, rescue experiments significantly indicated that knockdown of Lnc-OC1 inhibited cell growth through repressing PD-L1 expression at least partially. Concisely, our results proved that Lnc-OC1/miR-34a/PD-L1 axis might serve as a therapeutic target of EC.

Long non‑coding RNA SNHG12 regulates cell proliferation, invasion and migration in endometrial cancer by targeting miR‑4429

Long non-coding RNA small nucleolar RNA host gene 12 (SNHG12) has been demonstrated to be oncogenic. The aim of the present study was to examine the effects of SNHG12 on the progression of endometrial cancer (EC). The expression levels of SNHG12 and microRNA (miR)-4429 were assessed in EC cell lines by reverse transcription-quantitative PCR. Plasmids, including SNHG12 short hairpin RNAs (shRNAs), shRNA negative control (NC), SNHG12 overexpression (OV), OV-NC, miR-4429 mimic and mimic-NC, were transfected into RL95-2 cells. Post-transfection, Cell Counting Kit-8, Transwell Matrigel and wound-healing assays were performed to assess cell proliferation, invasion and migration, respectively. Cell cycle phase distribution was assessed by flow cytometry. The protein expression levels of matrix metalloproteinase (MMP)2 and MMP9 were detected by western blotting. miR-4429 target genes were predicted by bioinformatics analysis using target prediction online tools; the findings of this analysis were verified using a dual-luciferase reporter system. Identified as a target of miR-4429, SNHG12 was overexpressed in EC cell lines with decreased expression of miR-4429. Further experiments demonstrated that SNHG12 silencing and overexpression of miR-4429 markedly suppressed proliferation, migration and invasion of RL95-2 cells, arrested cells in the G₁ phase, and markedly downregulated the expression of MMP2 and MMP9. The opposite effects were observed in miR-4429 mimic-transfected RL95-2 cells after SNHG12 was overexpressed. The findings of the present study established the role of SNHG12 and miR-4429 in EC. Therefore, targeting the SNHG12/miR-4429 axis could serve as a potential future therapeutic target for treatment of EC.

Identification of long noncoding RNA RP11-89K21.1 and RP11-357H14.17 as prognostic signature of endometrial carcinoma via integrated bioinformatics analysis

Background

Endometrial carcinoma (EC) is one of the most common malignant tumors in gynecology. The potential functions and mechanisms of long noncoding RNAs (lncRNAs) in the occurrence and progression of EC remains unclear. It’s meaningful to explore lncRNAs signature for providing prognostic value of EC.

Methods

The differentially expressed lncRNAs and their prognostic values in EC were investigated based on The Cancer Genome Atlas (TCGA) database; the transcriptional factors (TFs), the competing endogenous RNA (ceRNA) mechanism, functional regulatory network and immune infiltration of RP11-89K21.1 and RP11-357H14.17 were further explored by various bioinformatics tools and databases.

Results

We firstly identified high expression of RP11-89K21.1 and RP11-357H14.17 were closely associated with shorten overall survival (OS) and poor prognosis in patients with EC. We also elucidated the networks of transcription factor and co-expression genes associated with RP11-89K21.1 and RP11-357H14.17. Furthermore, the ceRNA network mechanism was successfully constructed through 2 lncRNAs (RP11-89K21.1 and RP11-357H14.17), 11 miRNAs and 183 mRNAs. Functional enrichment analysis revealed that the targeting genes of RP11-89K21.1 and RP11-357H14.17 were strongly associated with microRNAs in cancer, vessel development, growth regulation, growth factor and cell differentiation, and involved in pathways including pathways in cancer, microRNAs in cancer and apoptotic signaling pathway.

Conclusions

We demonstrated for the first time that RP11-89K21.1 and RP11-357H14.17 may play crucial roles in the occurrence, development and malignant biological behavior of EC, and can be regarded as potential prognostic biomarkers for EC.