Extracellular vesicle-mediated transfer of the lncRNA-TC0101441 promotes endometriosis migration/invasion.

Extracellular vesicular long noncoding RNAs (lncRNAs) to influence recipient cells is emerging as a novel mechanism for disease progression. TC0101441 is a newly identified metastasis-related lncRNA involved in cancer. Since endometriosis exhibits prometastasis behavior similar to those observed in cancer, we aimed to investigate whether TC0101441 is involved in endometriosis and, if so, whether extracellular vesicular TC0101441 contributes to the migration/invasion of endometriotic cyst stromal cells (ECSCs). Clinically, we found that TC0101441 was highly expressed in ectopic endometria than in the eutopic and normal endometria. Serum extracellular vesicular TC0101441 levels were substantially increased in patients at stage III/IV endometriosis in comparison with stage I/II endometriosis and controls. In vitro, using TC0101441-high-expression ECSCs (ECSCs-H) as extracellular vesicles (EVs)-generating cells and TC0101441-low-expression ECSCs (ECSCs-L) as recipient cells, we observed that the PKH67-labeled ECSCs-H-derived EVs were effectively internalized by ECSCs-L. ECSCs-H-derived EVs shuttling TC0101441 were transferred to ECSCs-L, modulating their migratory/invasive abilities partially by regulating certain metastasis-related proteins, which eventually facilitated endometriosis migration/invasion. This study elucidates a potential crosstalk between ECSCs via EVs in endometriotic milieus, suggests a novel mechanism for endometriosis migration/invasion from the perspective of the "extracellular vesicular transfer of lncRNAs" and highlights the potential of circulating extracellular vesicular TC0101441 as a biomarker for endometriosis.

Long noncoding RNA TC0101441 induces epithelial-mesenchymal transition in epithelial ovarian cancer metastasis by downregulating KiSS1.

Peritoneal metastasis is a critical feature and clinical challenge in epithelial ovarian cancer (EOC). We previously identified a novel long noncoding RNA (lncRNA, TC0101441) in epithelial ovarian cancer (EOC) using microarrays. However, the impact of TC0101441 on EOC metastasis and prognosis remains unclear. TC0101441 expression in EOC tissues and its correlation with clinicopathological factors and prognosis were examined. A series of in vitro and in vivo assays were performed to elucidate the roles and mechanism of TC0101441 in EOC metastasis. We found that TC0101441 levels were elevated in EOC tissues compared with those in normal controls and significantly correlated with an advanced clinical stage and lymph node metastasis. TC0101441 was determined to be an independent prognostic predictor of overall survival (OS) and disease-free survival (DFS). Furthermore, loss-of-function assays showed that TC0101441 promoted the invasive and metastatic capacities of EOC cells both in vitro and in vivo. Mechanistically, the prometastatic effects of TC0101441 were linked to the induction of epithelial-mesenchymal transition (EMT). Importantly, KiSS1 was identified as a downstream target gene of TC0101441 and was downregulated by TC0101441 in EOC cells. After TC0101441 was silenced, the corresponding phenotypes of EOC cell invasion and EMT were reversed by the overexpression of KiSS1. Taken together, our data suggest that TC0101441 functions as a potential promigratory/invasive oncogene by promoting EMT and metastasis in EOC through downregulation of KiSS1, which may represent a novel prognostic marker and therapeutic target in EOC.

The long non-coding RNA HOTAIR promotes the proliferation of serous ovarian cancer cells through the regulation of cell cycle arrest and apoptosis.

HOX transcript antisense RNA (HOTAIR) is a well-known long non-coding RNA (lncRNA) whose dysregulation correlates with poor prognosis and malignant progression in many forms of cancer. Here, we investigate the expression pattern, clinical significance, and biological function of HOTAIR in serous ovarian cancer (SOC). Clinically, we found that HOTAIR levels were overexpressed in SOC tissues compared with normal controls and that HOTAIR overexpression was correlated with an advanced FIGO stage and a high histological grade. Multivariate analysis revealed that HOTAIR is an independent prognostic factor for predicting overall survival in SOC patients. We demonstrated that HOTAIR silencing inhibited A2780 and OVCA429 SOC cell proliferation in vitro and that the anti-proliferative effects of HOTAIR silencing also occurred in vivo. Further investigation into the mechanisms responsible for the growth inhibitory effects by HOTAIR silencing revealed that its knockdown resulted in the induction of cell cycle arrest and apoptosis through certain cell cycle-related and apoptosis-related proteins. Together, these results highlight a critical role of HOTAIR in SOC cell proliferation and contribute to a better understanding of the importance of dysregulated lncRNAs in SOC progression.

Aberrant expression of long noncoding RNAs in colorectal cancer with liver metastasis.

Long noncoding RNA (lncRNA) plays a crucial role in the regulation of various cellular processes and human diseases. However, little is known about the role of lncRNAs in colorectal liver metastasis (CLM). In the present study, we aimed to determine whether lncRNAs are differentially expressed in CLM tissue and to further assess their clinical value. lncRNA arrays were employed to screen for differentially expressed lncRNAs in colorectal cancer (CRC) tissues with synchronous, metachronous, or nonliver metastasis. Based on bioinformatics data, a quantitative reverse-transcription polymerase chain reaction (qRT-PCR) assay was performed to identify target lncRNAs in an expanded set of CRC samples with various subtypes of liver metastasis. The relationships between the target lncRNAs and the clinical characteristics and patient prognosis were further analyzed. After determining the expression profile of lncRNAs (n = 1332) in CLM tissue, 40 differentially expressed lncRNAs that were potentially related to CLM were selected for further examination in an expanded set of clinical samples, and three novel target lncRNAs, termed lncRNA-CLMAT1-3, were verified. High lncRNA-CLMAT3 expression strongly correlated with liver metastasis (P = 0.03) and lymph node metastasis (P = 0.009). Moreover, patients displaying high lncRNA-CLMAT3 expression exhibited a shorter median overall survival duration than those displaying low lncRNA-CLMAT3 expression (30.7 vs. 35.2 months, P = 0.007). Multivariate analysis demonstrated that the lncRNA-CLMAT3 expression level is an independent prognostic factor (hazard ratio 2.05, P = 0.02) after adjusting for other known prognostic factors. lncRNA-CLMAT3 over-expression was significantly associated with CLM and was an independent predictor of poor survival for patients with CRC.

Overexpression of long non-coding RNA HOTAIR predicts poor patient prognosis and promotes tumor metastasis in epithelial ovarian cancer.

OBJECTIVES: Although long non-coding RNAs (lncRNAs) are emerging as new regulators in the cancer paradigm, the involvement of lncRNAs in epithelial ovarian cancer (EOC) is just beginning to be studied. In this study, we focused on lncRNA HOX transcript antisense RNA (HOTAIR) and investigated its expression pattern, clinical significance, and biological function in EOC. METHODS: HOTAIR expression in EOC tissues was examined and its correlation with clinicopathological factors and patient prognosis was analyzed. A series of in vitro and in vivo assays were performed to understand the role of HOTAIR in EOC metastasis. RESULTS: HOTAIR expression was elevated in EOC tissues, and HOTAIR levels were highly positively correlated with the FIGO stage, the histological grade of the tumor, lymph node metastasis, and reduced overall survival (OS) and disease-free survival (DFS). A multivariate analysis showed that HOTAIR expression is an independent prognostic factor of OS and DFS in patients with EOC. Additionally, the results of in vitro assays showed that the suppression of HOTAIR expression in the three highly metastatic EOC cell lines (SKOV3.ip1, HO8910-PM, and HEY-A8) significantly reduced cell migration/invasion. The results of in vivo assays further confirmed the pro-metastatic effects of HOTAIR. Moreover, the pro-metastatic effects of HOTAIR were partially mediated by the regulation of certain matrix metalloproteinases (MMPs) and epithelial-to-mesenchymal transition (EMT)-related genes. CONCLUSIONS: Our data suggest that HOTAIR plays a vital role in EOC metastasis and could represent a novel prognostic marker and potential therapeutic target in patients with EOC.

Prognostic value of centromere protein-A expression in patients with epithelial ovarian cancer.

Altered expression of centromere protein-A (CENP-A) is observed in various types of human cancers. However, the clinical significance and pathological role of CENP-A in epithelial ovarian cancer (EOC) remains unclear. The main objective of this investigation was to clarify the relationships between CENP-A expression and the clinicopathological features of patients with EOC. Real-time quantitative PCR and Western blot were performed to examine CENP-A expression in 20 pairs of fresh-frozen EOC tissues and corresponding noncancerous tissues. Using immunohistochemistry, we performed a retrospective study of the CENP-A expression levels on 120 archival EOC paraffin-embedded samples. Prognostic outcomes correlated with CENP-A were examined using Kaplan-Meier analysis and Cox proportional hazards model. Our results showed that the expression levels of CENP-A mRNA and protein in EOC tissues were both significantly higher than those in noncancerous tissues. By immunohistochemistry, the data revealed that high CENP-A expression was significantly correlated with pathological grade (P = 0.02) and International Federation of Gynecology and Obstetrics stage (P = 0.006). Consistent with these results, we found that high expression of CENP-A was significantly correlated with poor survival in EOC patients (P < 0.001). Furthermore, Cox regression analyses showed that CENP-A expression was an independent predictor of overall survival. Our data suggest that CENP-A could play an important role in EOC and might serve as a valuable prognostic marker and potential target for gene therapy in the treatment of EOC.

Transvaginal color Doppler sonography predicts ovarian interstitial fibrosis and microvascular injury in women with ovarian endometriotic cysts.

OBJECTIVE: To determine novel predictors of ovarian interstitial fibrosis and microvascular injury associated with ovarian endometriotic cysts (OECs). DESIGN: Case-control study. SETTING: The gynecology unit of an affiliated hospital in China. POPULATION: Women <40 years of age with OECs or benign ovarian tumors (controls). METHODS: Transvaginal color Doppler sonography was performed preoperatively to detect ovarian interstitial flow. Postoperatively, expressions of transforming growth factor-ß1 (TGF-ß1) and thrombospondin-1 (TSP-1), as well as microvessel density in ovarian interstitial, were analyzed using immunohistochemistry. MAIN OUTCOME AND MEASURES: Ovarian interstitial flow and expressions of TGF-ß1, TSP-1, and microvessel density. RESULTS: Compared with controls, ovarian interstitial flow in the study group was decreased and arterial spectra indicated significantly higher resistance indices. Microvessel density was reduced, but TGF-ß1 and TSP-1 were elevated in the study group. There was a positive correlation between TGF-ß1 and TSP-1. There were negative correlations between TGF-ß1 and microvessel density, and between TSP-1 and microvessel density. Microvessel density and resistance indices were negatively correlated, whereas the correlations of TGF-ß1 and TSP-1 with resistance indices were positive. CONCLUSIONS: Resistance indices are consistent with pathological indices. Changes in resistance indices in ovaries with endometriosis are related to interstitial fibrosis and microvascular injury.

Ovarian interstitial blood flow changes assessed by transvaginal colour Doppler sonography: predicting ovarian endometrioid cyst-induced injury to ovarian interstitial vessels.

PURPOSE: To evaluate the blood flow changes and their relationships to microvessel density (MVD) and thrombospondin-1 (TSP-1) by transvaginal colour Doppler sonography (TV-CDS) in the ovarian interstitium to predict ovarian interstitial microvascular injury in the pathological process of ovarian endometrial cysts (OEC). METHODS: TV-CDS was preoperatively performed to detect blood flow changes in 60 patients with 76 ovarian endometrioid cysts, and flow classification and resistance indices (RI) values were recorded for analysis. Ovarian interstitial specimens with blood flow signals were collected for postoperative pathologic examination. TSP-1 protein was evaluated by immunohistochemistry and Western blot, TSP-1 mRNA by reverse transcriptase polymerase chain reaction, microvessels by CD34 antibody, and MVD by image analysis. Thirty age-matched patients with benign ovarian tumours served as controls. RESULTS: Blood flow, most of star-shaped, within ovarian interstitial arteries in the OEC group was diminished; however, arterial spectra exhibited a high-resistance flow manifesting a significantly higher RI compared with that of the control group (P < 0.01). In ovarian interstitial specimens, there were significantly (P < 0.01) lower CD34-MVD and higher TSP-1 protein and mRNA in the OEC group than in the controls. CD34-MVD and TSP-1 showed remarkably negative correlation (rs = -0.76, P < 0.01). RI values correlated negatively with MVD values (rs = -0.91, P < 0.01), but positively with TSP-1 (rs = 0.81, P < 0.01), while flow classification correlated positively with MVD values (rs = 0.66, P < 0.01), but negatively with TSP-1 (rs = -0.54, P < 0.01). CONCLUSIONS: Changes in CD34-MVD and TSP-1 reflected ovarian interstitial microvascular injury of OEC, pathologically supported the findings of blood flow changes within ovarian interstitial arteries, and prospectively predicted OEC-induced ovarian interstitial vessel injury. This has important clinical value: early treatment, instead of allowing the cyst to become bigger, is of great importance for OEC patients, because a greater number of functional tissue blood vessels would be destroyed as the disease progresses.

Accumulation of dysfunctional tumor-infiltrating PD-1+ DCs links PD-1/PD-L1 blockade immunotherapeutic response in cervical cancer.

Various predictive biomarkers are needed to select candidates for optimal and individualized treatments. Tumor-infiltrating immune cells have gained increasing interest in cancer research for the prediction of therapeutic response and survival. However, the role of dendritic cells (DCs) in PD-1 blockade immunotherapy remains unclear. In this study, we identified a population of PD-1+ DCs in the tumor microenvironment (TME) of cervical cancer (CC). The accumulation of PD-1+ DCs in cervical tumors was correlated with advanced stages, elevated preoperative squamous cell carcinoma antigen levels and lymph-vascular space invasion. PD-1 expression was induced on activated tumor-associated DCs (TADCs) in vitro compared with their resting counterparts. This PD-1+ DC population was characterized by reduced secretion of cytokines (IL-12, TNF-α, and IL-1ß) and dysfunctional induction of T cell proliferation and cytotoxic reaction. PD-1 blockade significantly reinvigorated PD-1+ DCs to release IL-12, TNF-α, and IL-1ß compared with PD-1- DCs. TILs from samples with higher PD-1+ DC infiltration could be induced to achieve a greater killing effect of PD-1 blockade treatment. Our findings suggested a role for PD-1+ DCs in immune surveillance dysfunction and CC progression. PD-1+ DC density in the TME may serve as a diagnostic factor for predicting the optimal beneficiaries of PD-1/PD-L1 blockade immunotherapy in CC.

Extracellular vesicular Wnt7b mediates HPV E6-induced cervical cancer angiogenesis by activating the ß-catenin signaling pathway.

BACKGROUND: The E6 oncoproteins of human papillomavirus (HPV) 16/18 are the critical drivers of cervical cancer (CC) progression. Extracellular vesicles (EVs) are emerging as critical mediators of cancer-tumor microenvironment (TME) communication. However, whether EVs contribute to HPV 16/18 E6-mediated impacts on CC progression remains unclear. METHODS: A series of in vitro and in vivo assays were performed to elucidate the roles and mechanism of EV-Wnt7b in HPV E6-induced CC angiogenesis. The prognostic value of serum EV-Wnt7b was determined and a predictive nomogram model was established. RESULTS: HPV 16/18 E6 upregulated Wnt7b mRNA expression in four HPV 16/18-positive CC cell lines and their EVs. In vitro and in vivo experiments demonstrated that EV-Wnt7b mRNA was transferred to and modulated human umbilical vein endothelial cells (HUVECs) toward more proliferative and proangiogenic behaviors by impacting ß-catenin signaling. Clinically, serum EV-Wnt7b levels were elevated in CC patients and significantly correlated with an aggressive phenotype. Serum EV-Wnt7b was determined to be an independent prognostic factor for CC overall survival (OS) and recurrence-free survival (RFS). Notably, we successfully established a novel predictive nomogram model using serum EV-Wnt7b, which showed good prediction of 1- and 3-year OS and RFS. CONCLUSIONS: Our results illustrate a potential crosstalk between HPV 16/18-positive CC cells and HUVECs via EVs in the TME and highlight the potential of circulating EV-Wnt7b as a novel predictive biomarker for CC prognosis.

The Exosomal Long Noncoding RNA aHIF is Upregulated in Serum From Patients With Endometriosis and Promotes Angiogenesis in Endometriosis.

OBJECTIVE: The transfer of long noncoding RNAs (lncRNAs) via exosomes to modulate recipient cells represents an important mechanism for disease progression. Antisense hypoxia-inducible factor (aHIF) is a well-known angiogenesis-related lncRNA. Here, we aimed to investigate the clinical implications of aHIF and exosomal aHIF in endometriosis and the involvement of exosome-shuttled aHIF in endometriosis angiogenesis. STUDY DESIGN: The distribution and expression of aHIF in ectopic, eutopic, and normal endometria was evaluated. Serum exosomal aHIF levels in patients with endometriosis were tested. The correlation between serum exosomal aHIF and aHIF expression in ectopic endometria was analyzed. Endometriotic cyst stromal cells (ECSCs)-derived exosomes were characterized. The internalization of exosomes by human umbilical vein endothelial cells (HUVECs) was observed. A series of in vitro assays were conducted to investigate the roles and mechanisms of exosomal aHIF in endometriosis angiogenesis. RESULTS: Clinically, aHIF was highly expressed in ectopic endometria and serum exosomes in patients with endometriosis. Serum exosomal aHIF was significantly correlated to aHIF expression in matched ectopic endometria. In vitro, PKH67-labeled exosomes derived from aHIF high expression ECSCs were effectively internalized by recipient HUVECs. Notably, exosome-shuttled aHIF was transferred from ECSCs to HUVECs, which in turn elicited proangiogenic behavior in HUVECs by activating vascular endothelial growth factor (VEGF)-A, VEGF-D, and basic fibroblast growth factor, thereby facilitating endometriosis angiogenesis. CONCLUSION: Our study illustrates a potential cell-cell communication between ECSCs and HUVECs in an ectopic environment, provides a novel mechanistic model explaining how ECSCs induce angiogenesis from the perspective of the "exosomal transfer of aHIF," and highlights the clinical value of circulating exosomal aHIF in endometriosis.

Natural antisense transcript of hypoxia-inducible factor 1 regulates hypoxic cell apoptosis in epithelial ovarian cancer.

PURPOSE: Hypoxia is a key stress that triggers apoptosis in various tumors, including epithelial ovarian cancer (EOC). Previous researches identified a hypoxia-upregulated lncRNA named "a natural antisense transcript of hypoxia-inducible factor 1 (aHIF)" in some tumors. However, the contribution of aHIF to EOC remains unclear. Here, we aimed to investigate the expression, function, and underlying mechanisms of aHIF in EOC progression under hypoxia. MATERIALS AND METHODS: Expression levels of aHIF in EOC tissues were tested. In vitro and in vivo assays were conducted to explore the function and mechanism of aHIF in hypoxia-induced EOC progression. RESULTS: aHIF levels were increased in EOC tissues and were upregulated by hypoxia in EOC cells. Functional data revealed that aHIF knockdown accelerated cell apoptosis under hypoxia and inhibited EOC tumorigenesis and tumor growth in vivo. Additionally, aHIF overexpression inhibited cell apoptosis and enhanced cell proliferation under hypoxia in EOC. Mechanistically, the dysregulation of certain key mitochondrial apoptosis pathway-related genes, including Bcl-2, Bax, Caspase-7, and Caspase-9, may partially explain aHIF-regulated EOC apoptosis and growth under hypoxia. CONCLUSION: These data provide the first convincing evidence that aHIF may inhibit EOC apoptosis and thereby promote tumor growth through activation of the mitochondrial apoptosis pathway under hypoxia. Our findings help clarify the role of lncRNA in hypoxia-induced EOC progression.

Exosomal Metastasis­Associated Lung Adenocarcinoma Transcript 1 Promotes Angiogenesis and Predicts Poor Prognosis in Epithelial Ovarian Cancer.

Exosomes mediate cell-cell crosstalk in cancer progression by transferring their molecular cargos, including long noncoding RNAs (lncRNAs). Metastasis­associated lung adenocarcinoma transcript 1 (MALAT1) is a well-known lncRNA associated with cancer angiogenesis and metastasis. However, the presence of MALAT1 in exosomes and the roles and clinical values of exosomal MALAT1 in epithelial ovarian cancer (EOC) remain unknown. The present study focused on the crosstalk between EOC cells and endothelial cells mediated by exosomal MALAT1 and aimed to explore the roles of exosomes and exosomal MALAT1 in EOC angiogenesis and to reveal the clinical relevance and prognostic predictive value of serum exosomal MALAT1 in EOC. We observed that MALAT1 was increased in both metastatic EOC cells and their secreted exosomes. Exosomal MALAT1 derived from EOC cells was transferred to recipient human umbilical vein endothelial cells (HUVECs) via exosomes. In vitro and in vivo experiments demonstrated that MALAT1 knockdown impaired the exosome-mediated proangiogenic activity of HUVECs through certain key angiogenesis-related genes. Clinically, elevated serum exosomal MALAT1 was highly correlated with an advanced and metastatic phenotype of EOC and was an independent predictive factor for EOC overall survival (OS). Moreover, a prognostic nomogram model we constructed showed a good prediction of the probability of 3-year OS of EOC patients according to the c-index (0.751, 95% confidence interval [CI]=0.691-0.811) and calibration curve. Collectively, our data provide a novel mechanism by which EOC cells transfer MALAT1 via exosomes to recipient HUVECs and influence HUVECs by stimulating angiogenesis-related gene expression, eventually promoting angiogenesis. Additionally, circulating exosomal MALAT1 can serve as a promising serum-based, noninvasive predictive biomarker for EOC prognosis.

ElncRNA1, a long non-coding RNA that is transcriptionally induced by oestrogen, promotes epithelial ovarian cancer cell proliferation.

Previously, the novel oestrogen (E2)-upregulated lncRNA TC0101441, was identified by us, via microarray analysis. However, the detailed mechanism by which E2 upregulates TC0101441 and the role of TC0101441 in epithelial ovarian cancer (EOC) progression have not been elucidated. In the present study, we further analysed TC0101441, which we designated oestrogen-induced long non-coding RNA-1 (ElncRNA1). We showed that E2 transcriptionally upregulates ElncRNA1 through the oestrogen receptor α (ERα)-oestrogen response element (ERE) pathway using RNA stability assays, bioinformatics-based searches for ERE binding sites, chromatin immunoprecipitation (ChIP) assays and dual luciferase reporter assays. Clinically, ElncRNA1 levels are significantly higher in EOC tissues than in normal ovarian surface epithelium. In vitro and in vivo loss-of-function assays revealed that ElncRNA1 promotes EOC cell proliferation. This pro-proliferation effect of ElncRNA1 was partially mediated by the regulation of CDK4, CDK6 and cyclin D1. These findings provide the first evidence that E2 upregulates ElncRNA1 at the transcriptional level through the ERα-ERE pathway and that this novel E2-upregulated lncRNA has an oncogenic role in EOC growth. The placement of ElncRNA1 in the E2-ERα-ERE signalling pathway may provide greater insight into the effects of oestrogen on EOC progression from the perspective of lncRNA.

The long non-coding RNA ANRIL promotes proliferation and cell cycle progression and inhibits apoptosis and senescence in epithelial ovarian cancer.

Antisense non-coding RNA in the INK4 locus (ANRIL) has been implicated in a variety of cancers. In the present study, we evaluated ANRIL expression in epithelial ovarian cancer (EOC) and defined its clinical implications and biological functions. ANRIL was overexpressed in EOC tissues relative to normal controls. Overexpression correlated with advanced International Federation of Gynecologists and Obstetricians stage and high histological grade. Multivariate analysis indicated that ANRIL is an independent prognostic factor for overall survival in EOC. Gain- and loss-of-function experiments demonstrated that ANRIL promotes EOC cell proliferation both in vitro and in vivo. The proliferative effect was linked to the promotion of cell cycle progression and inhibition of apoptosis and senescence. Down-regulation of P15INK4B and up-regulation of Bcl-2 by ANRIL may partially explain ANRIL-induced EOC cell proliferation. This study is the first to establish that ANRIL promotes EOC progression and is a potential prognostic biomarker.

Downregulated long non-coding RNA CLMAT3 promotes the proliferation of colorectal cancer cells by targeting regulators of the cell cycle pathway.

Over-expression of long non-coding RNA (lncRNA)-CLMAT3 is significantly associated with colorectal liver metastasis and is an independent predictor of poor survival for colorectal cancer patients. However, as little is known regarding the role of this gene in the proliferation of colorectal cancer in vitro, we investigated the involvement of lncRNA-CLMAT3 in colorectal cancer cell proliferation. In this study, we demonstrate that lncRNA-CLMAT3 expression was significantly increased in colorectal cancer cells compared with a normal intestinal mucous cell line and that inhibition of lncRNA-CLMAT3 suppressed colorectal cancer cell proliferation in vitro. We also found that this reduced colorectal cancer cell proliferation due to lncRNA-CLMAT3 knockdown is associated with G0/G1 cell-cycle arrest induction and apoptosis enhancement. Furthermore, lncRNA-CLMAT3 knockdown enhanced Cdh1 expression and resulted in p27Kip accumulation via increased Skp2 protein ubiquitination. Taken together, our findings suggest that reducing lncRNA-CLMAT3 inhibits colorectal cancer cell proliferation by affecting cell cycle components.

Involvement of long non-coding RNA in colorectal cancer: From benchtop to bedside (Review).

Colorectal cancer (CRC) is one of the greatest threats to public health. Recent advances in whole-genome transcriptome analyses have enabled the identification of numerous members of a novel class of non-coding (nc)RNA, long ncRNA (lncRNA), which is broadly defined as RNA molecules that are >200 nt in length and lacking an open reading frame. In the present review, all lncRNAs associated with CRC are briefly summarized, with a particular focus on their potential roles as clinical biomarkers. CRC-associated lncRNAs involved in the underlying mechanisms of CRC progression are also initially included. This should benefit the development of novel markers and effective therapeutic targets for patients with CRC.

Long non-coding RNA ANRIL predicts poor prognosis and promotes invasion/metastasis in serous ovarian cancer.

Recent studies have highlighted the role of long non-coding RNAs (lncRNAs) in carcinogenesis and have suggested that genes of this class might be used as biomarkers in cancer. However, whether lncRNAs are involved in serous ovarian cancer (SOC) remains largely unknown. In the present study, we focused on lncRNA antisense non-coding RNA in the INK4 locus (ANRIL) and investigated its expression pattern, clinical significance, and biological function in SOC. We found that ANRIL levels were elevated in SOC tissues compared with normal controls and were highly correlated with advanced FIGO stage, high histological grade, lymph node metastasis, and poor prognosis. Multivariate analysis further revealed that ANRIL is an independent prognostic factor for predicting overall survival of SOC patients. In vitro, we compared differential ANRIL levels between SOC parental cell lines (SK-OV-3, HO8910) and highly metastatic sublines (SK-OV-3.ip1, HO8910-PM). Notably, ANRIL was highly expressed in both SK-OV-3.ip1 cells and HO8910-PM cells. SiRNA-mediated ANRIL silencing in these cells impaired cell migration and invasion. Based on the metastasis-related mRNA microarray analysis and subsequent western blotting confirmation, we found that MET and MMP3 are key downstream genes of ANRIL involved in SOC cell migration/invasion. Together, our data suggest that lncRNA ANRIL plays an important role in SOC invasion/metastasis and could represent a novel biomarker for predicting poor survival as well a promising therapeutic target.

Expression and clinical significance of estrogen-regulated long non-coding RNAs in estrogen receptor α-positive ovarian cancer progression.

Estrogen (E2) has long been implicated in epithelial ovarian cancer (EOC) progression. The effects of E2 on cancer progression can be mediated by numerous target genes, including coding RNAs and, more recently, non-coding RNAs (ncRNAs). Among the ncRNAs, long ncRNAs (lncRNAs) have emerged as new regulators in cancer progression; therefore, our aim was to determine whether the expression of any lncRNAs is regulated by E2 and, if so, whether a subset of these lncRNAs have some clinical significance in EOC progression. A microarray was performed to identify E2-regulated lncRNAs in E2 receptor (ER) α-positive EOC cells. Bioinformatics analyses of lncRNAs were conducted, focusing on gene ontology and pathway analyses. Quantitative real-time polymerase chain reactions were performed to confirm the expression of certain lncRNAs in ERα-positive EOC tissues. The correlation between certain lncRNA expression and clinicopathological factors as well as prognosis in ERα-positive EOC patients was then analyzed. We showed that 115 lncRNAs exhibited significant changes in E2-treated SKOV3 cells compared with untreated controls. Most of these lncRNAs were predicated to have potential to contribute to cancer progression. Notably, three candidates (TC0100223, TC0101686 and TC0101441) were aberrantly expressed in ERα-positive compared to ERα-negative EOC tissues, showing correlations with some malignant cancer phenotypes such as advanced FIGO stage and/or high histological grade. Furthermore, multivariate analysis indicated that TC0101441 was an independent prognostic factor for overall survival. Taken together, these results indicate for the first time that E2 can modulate lncRNA expression in ERα-positive EOC cells and that certain lncRNAs are correlated with advanced cancer progression and suggestive of a prognostic indicator in ERα-positive EOC patients. Knowledge of these E2-regulated lncRNAs could aid in the future understanding of the estrogenic effect on EOC progression and may assist in the clinical design of new target therapies based on a perspective of lncRNA.