lncRNA GHET1 regulates extravillous trophoblastic phenotype via EZH2/LSD1-mediated MT2A epigenetic suppression in pre-eclampsia.

Pre-eclampsia (PE) is usually defined as new-onset hypertension with albuminuria or other organ damage. Herein, the role and mechanism of long noncoding RNA (lncRNA) gastric carcinoma high expressed transcript 1 (GHET1) during PE are investigated. Expression of GHET1 in PE pregnancies was evaluated using quantitative real-time polymerase chain reaction (qRT-PCR). Proliferation and cell cycle of extravillous trophoblasts were assessed by Cell Counting Kit-8 (CCK-8), colony formation, 5-Ethynyl-2'-deoxyuridine (EdU) assays, and flow cytometry, respectively. Migration, invasion, and network formation of trophoblasts were measured by wound healing, transwell system, and tube formation assays. RNA immunoprecipitation (RIP), RNA pull-down, and chromatin immunoprecipitation (ChIP) assays were used to confirm the molecular interaction. GHET1 was markedly decreased in the placenta of PE patients. GHET1 promoted the proliferation and cell cycle of extravillous trophoblasts, as well as migration, invasion, and network formation in vitro. Metallothionein 2A (MT2A) functioned as a downstream effector of GHET1, which was negatively correlated with GHET1 in PE. GHET1 directly bound with zeste 2 polycomb repressive complex 2/lysine-specific demethylase 1 (EZH2/LSD1). Knockdown of GHET1 reduced the occupancies of H3K27me3 and H3K4me2 in the MT2A promoter region by recruiting EZH2 and LSD1. MT2A knockdown reversed GHET1 inhibition mediated biological functions. GHET1 regulates extravillous trophoblastic phenotype via EZH2/LSD1-mediated MT2A epigenetic suppression in PE.

A review on the role of GHET1 in different cancers.

Gastric cancer High Expressed Transcript 1 (GHET1) is an RNA gene located on chromosome 7q36.1. This non-coding RNA is involved in the pathology of different cancers. It can regulate cell proliferation, apoptosis and cell cycle transition. Moreover, it induces epithelial-mesenchymal transition. Up-regulation of GHET1 has been correlated with poor prognosis of patients with different malignancies. Besides, its up-regulation has been mostly detected in later stages and advanced grades of cancers. This review summarizes recent studies on the expression of GHET1, its in vitro functions, and its impact on the beginning and progression of cancer based on xenograft models of cancer.

Long noncoding RNA GHET1 promotes cell proliferation through oxidative stress in prostate cancer.

Gastric carcinoma high expressed transcript 1 (GHET1) is an oncogenic Long noncoding RNA. GHET1 expression promotes multiple levels of developing a complex molecular network. The main purpose of the study was to investigate the mechanism by which long noncoding RNA (lncRNA) GHET1 promotes prostate cancer cell proliferation and related metabolism. In vitro study, lncRNA GHET1 was overexpressed in LN-cap, PC-3, 22RV1, and C4-2 cells. The cell viability was measured by MTT and trans-well assay. A flow cytometer was also used to detect cell cycles and apoptosis. Western blot analysis was used for protein expression validation. mRNA expression was detected by real-time PCR. lncRNA GHET1 enhanced cell proliferation, migration, and could resist paclitaxel-induced apoptosis and cell cycle arrest GHET1 expression stimulates reactive oxygen species (ROS) level upregulated in prostate cancer cells, increased the expression of HIFα, IL-1B and IL-6, and activated ROS/STAT-3/Twsit1 signaling pathway. Knockdown GHET1 could reduce cell proliferation and migration due to the overexpression of GHET1. lncRNA GHET1 promotes prostate cancer growth through oxidative stress signaling pathways and resists the antineoplastic drug paclitaxel, which can be used as a target for antineoplastic therapy and drug resistance therapy in the future in clinics.

Effect of LncRNA GHET1 on Proliferation, Apoptosis, and Metastasis of Gallbladder Cancer Cells by Targeting miR-27b / 肿瘤防治研究

Objective To investigate the effect of GHET1 on the biological behavior of gallbladder cancer cells and the regulatory mechanism of GHET1 on miR-27b. Methods The expression of GHET1 and miR-27b in 50 samples of gallbladder cancer was detected by real-time quantitative PCR. The si-NC vector, si-GHET1 vector, miR-27b inhibitor, and si-GHET1 vector+miR-27b inhibitor were transfected into SGC-996 cells and set as the control group, GHET1 interference group, miR-27b interference group, and GHET1+miR-27b interference group. Cell proliferation, apoptosis, and metastasis in each group were detected by MTT, flow cytometry, and Transwell assays. The regulatory effect of GHET1 on miR-27b was validated by luciferase reporter gene assay. Results GHET1 expression was higher in cancer tissues than that in paracancerous ones. miR-27b expression was lower in cancer tissues than that in paracancerous tissues. GHET1 was negatively correlated with miR-27b expression (P<0.05), and GHET1 expression was associated with TNM staging and lymph node metastasis (P<0.05). High GHET1 expression was associated with poor prognosis of patients with gallbladder cancer (P<0.05). Compared with the control group, the GHET1 interference group showed decreased cell-proliferation ability, increased apoptosis rate, and reduced number of cell metastasis. The miR-27b interference group showed increased cell-proliferation ability, decreased apoptosis rate, and increased number of cell metastasis (P<0.05). Compared with the GHET1 interference group, the GHET1+miR-27b interference group showed increased cell-proliferation ability, decreased apoptosis rate, and increased number of cell metastasis (P<0.05). GHET1 inhibited miR-27b expression by acting as a sponge of miR-27b. Conclusion GHET1 promotes the proliferation and metastasis and inhibits the apoptosis of gallbladder cancer cells by targeting miR-27b, suggesting that GHET1/miR-27b axis plays a role in gallbladder cancer progression.

LncRNA GHET1 Promotes Hypoxia-Induced Glycolysis, Proliferation, and Invasion in Triple-Negative Breast Cancer Through the Hippo/YAP Signaling Pathway.

OBJECTIVE: This study was to assess the specific impacts and mechanism of lncRNA GHET1 in the development of triple-negative breast cancer (TNBC). METHODS: The lncRNA GHET1 expression in TNBC tissues and adjacent healthy tissues was detected by qRT-PCR, and its expression was then measured at the cellular level, including TNBC cells and human normal breast epithelial cell line MCF10A. On the completion of transfection of negative shRNA or lncRNA GHET1 shRNA, the TNBC cells, HCC1937 and MDA-MB-468, were then cultured in a normoxia or hypoxia environment, respectively. 5-Ethynyl-2'-deoxyuridine (EdU) assay, colony formation assay, and transwell assay were applicable to the determination of cell proliferation, cell viability, and invasion in each group, respectively. Reagent kits were used for testing glucose consumption and lactate production levels. HCC1937 cells with knockdown or overexpression of lncRNA GHET1 were injected into the nude mice, followed by the examination of resulting tumor volume and weight. The distribution and expression of Hippo/YAP signaling pathway-related proteins were probed using western blotting. RESULTS: Highly expressed lncRNA GHET1 in TNBC tissues and cells and induction of lncRNA GHET1 by hypoxia were proved. Knockdown of lncRNA GHET1 significantly reduced proliferation, viability, and invasion of TNBC cells, and decreased glucose consumption and lactate production levels under the hypoxia condition. Furthermore, lncRNA GHET1 knockdown decreased HIF-1α expression in hypoxia and significantly inhibited tumor development in vivo. Knockdown of lncRNA GHET1 increased the phosphorylation levels of LATS1 and Yes-associated protein (YAP) to retain YAP within the cytoplasm, while the overexpression of lncRNA GHET1 or hypoxia promoted nuclear translocation of YAP and TNBC development. CONCLUSION: LncRNA GHET1 expression can be induced by hypoxia, which leads to excessive activation of the Hippo/YAP signaling pathway, thus promoting TNBC progression.

Long non-coding RNA GHET1 promotes thyroid cancer cell proliferation and invasion.

BACKGROUND: We aimed to evaluate the role of long non-coding RNA (LncRNA) gastric carcinoma proliferation-enhancing transcript 1 (GHET1) on thyroid cancer (TC) behavior in vitro. METHODS: TC tissues and paired adjacent normal tissues were obtained after surgical excision from 43 patients with TC. The expression of LncRNA GHET1 was analyzed by real-time (RT) PCR. Human papillary thyroid cancer cell lines (TPC-1, BCPAP) were used to examine the role of LncRNA GHET1 in vitro. Cell proliferation was determined by CCK8 and cell colony formation assays. Transwell and wound-healing assays were used to detect the invasion and migration of thyroid cancer cells. RESULTS: Our results showed that LncRNA GHET1 was significantly more upregulated in TC tissues than in adjacent normal tissues. LncRNA GHET1 was also increased in thyroid cancer cell lines compared to normal thyroid cell lines. The upregulation of LncRNA GHET1 was significantly associated with tumor invasion, gender, and lymph node metastasis in patients with thyroid cancer. The in vitro studies showed that silencing LncRNA GHET1 in BCPAP cells inhibited cell proliferation, cell invasion, and migration. Silencing of LncRNA GHETI also promoted the cell apoptotic rate, caused an increase in the cell population at the G0/G1 phase, and decreased the cell population at the S phase. In contrast, the overexpression of LncRNA GHET1 promoted cell proliferation, invasion, and migration, inhibited cell apoptosis, and increased cell population at the S phase in TPC cells. CONCLUSIONS: LncRNA GHET1 dysregulation might be involved in the carcinogenesis of thyroid cancer. LncRNA GHET1 could be used as a potential molecular marker and molecular target for TC.

Long non-coding RNA GHET1/miR-105/RAP2B axis regulates the progression of acute myeloid leukemia.

Background: To explore the biological effects and potential molecular mechanisms of long non-coding RNA (lncRNA) gastric carcinoma proliferation enhancing transcript 1 (GHET1) in acute myeloid leukemia (AML). Methods: Fluorescence in situ hybridization was performed to determine the location of GHET1. Quantitative polymerase chain reaction (qPCR) was performed to verify RNA expression. GHET1 overexpression and knockdown were achieved by transfection of the expression vector or short hairpin RNA. Western blotting, qPCR, Cell Counting Kit-8 assay, JC-1 staining, and flow cytometry were performed to measure GHET1 function. The dual luciferase reporter assay was performed to confirm the relationship between microRNA 105 (mir-105) and Ras-related protein Rap-2B (RAP2B). Results: GHET1 was localized in the nucleus of NB4 cell lines. GHET1 expression was elevated in AML cell lines compared with normal bone marrow mononuclear cells. GHET1 knockdown led to inhibition of proliferation and promoted the differentiation and apoptosis of AML cell lines. Furthermore, GHET1 directly bound to miR-105 and downregulated miR-105 expression. MiR-105 overexpression suppressed proliferation and induced the differentiation and apoptosis of AML cell lines. In addition, RAP2B was confirmed to be a target gene of miR-105 and an inverse correlation was shown between their expression levels in AML cell lines; when miR-105 increased, Rap-2B level decreased and vice versa. Conclusion: This study demonstrated that the GHET1/miR-105/Rap2B axis may be a critical signaling pathway involved in AML progression.

Clinicopathological Significance of Long Non-Coding RNA GHET1 in Human Cancers: A Meta-Analysis.

BACKGROUND: Cancer is considered as the main public health problem and the second leading cause of morbidity and mortality worldwide. Numerous environmental-lifestyle related risk factors account for around one-third of cancer deaths. Recently, the key role of lncRNAs has been widely investigated in a variety of disorders, including cancer. The lncRNA GHET1 has been considered as an essential oncogenic lncRNA in many types of human cancers. Clinical investigations indicated that expression of lncRNA GHET1 is correlated with clinicopathological characteristics in cancer. This metaanalysis investigated the correlation between the lncRNA GHET1 expression and clinicopathological features in different types of cancers. MATERIALS AND METHODS: Comprehensive literature searches in PubMed, Scopus, and Web of Knowledge were conducted up to April 11, 2019. Sixteen studies were included in this meta-analysis. All statistical analyses were conducted using Stata software, version 12.0. RESULTS: The pooled OR and 95%CIs of the sixteen relevant studies showed that over expression of lncRNA GHET1 was associated with tumor-size ≥5 cm (OR= 2.51, 95% CI: 1.89-3.33, p=0.00, I2=38.30%), positive lymph node metastasis (OR= 2.83, 95% CI: 1.78-4.52, p=0.00, I2=45.60%), advanced tumor stage (OR= 3.92, 95% CI: 2.97-5.19, p=0.00, I2=0.00%), positive distant metastasis (OR= 5.74, 95% CI: 2.58-12.77, p=0.00, I2=0.00%), advanced tumor status (OR= 2.97, 95% CI: 1.40- 6.29, p=0.01, I2=34.70%), and positive vascular invasion (OR= 2.69, 95% CI: 1.61-4.50, p=0.00, I2=29.20%). CONCLUSION: Taken together, the current study demonstrated that overexpression of lncRNA GHET1 is significantly associated with clinicopathological features in human cancers. Our results suggested that lncRNA GHET1 can be utilized as a prognostic biomarker in human cancer.

Aberrant Expression of Gastric Carcinoma High Expressed Transcript 1 is a Diagnostic and Prognostic Biomarker in Human Cancer.

BACKGROUND: Gastric carcinoma high expressed transcript 1 (GHET1), a long noncoding RNA (LncRNA), has been reported to be involved in tumor genesis and cancer progression. High GHET1 expression is correlated with a poor prognosis in cancer. In this meta-analysis, we investigated the association between GHET1 and lymph node metastasis, differentiation, vascular invasion and so on in human cancer. METHODS: We performed systematic search in PubMed, EMBASE, Wiley Online Library, Wiley Online Library, and Medline from January 1, 1996 to September 25, 2017. A total of 8 studies were selected for further research. RESULTS: The result showed that GHET1 expression was significantly associated with OS (hazard ratio [HR] = 2.23; 95% CI, 1.86-2.67; P < 0.0001), including digestive system tumor (HR = 2.17; 95% CI, 1.63-2.89; P < 0.0001). Moreover, high GHET1 expression was related to tumor size (odds ratio [OR] = 2.15, 95% CI: 1.57-2.94; P < 0.00001), TNM stage (Ⅲ+Ⅳ vs.Ⅰ+Ⅱ; OR = 4.02, 95% CI:3.06-5.28; P < 0.00001), lymph node metastasis (Yes vs. No; OR = 3.55, 95% CI:2.54-4.95; P < 0.00001), differentiation (poor vs. well or moderate; OR = 1.72, 95% CI:1.22-2.42; P = 0.002), vascular invasion (Yes vs. No; OR = 3.03, 95% CI:1.80-5.12; P = 0.00001). Also, we found that high expression of GHET1 has a significant relationship with analysis method and sample size. It almost higher in different human cancers. CONCLUSIONS: GHET1 may serve as a potential clinical biomarker and poor survival and high-risk recurrence in cancers.

Prognostic value of long non-coding RNA GHET1 in cancers: a systematic review and meta-analysis.

BACKGROUND: A number of studies have demonstrated the critical role of long non-coding RNA gastric cancer high expressed transcript 1 (GHET1) in many cancers. This meta-analysis provides an evidence-based evaluation of the prognostic role of GHET1 in cancer. MATERIALS AND METHODS: Literature searches were conducted in several databases including Medline, Cochrane, EMBASE, CNKI, and Wanfang. The pooled odds ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were used to evaluate the role of GHET1 in cancer. The study protocol was registered at PROSPERO (ID: CRD42018111252). RESULTS: Sixteen studies, containing 1315 patients, were analyzed in this meta-analysis. The pooled results indicated that GHET1 overexpression was significantly associated with poor overall survival (OS) and disease-free survival (DFS) in cancer. Moreover, up-regulation of GHET1 expression predicted larger tumor size, positive lymph node metastasis, positive distant metastasis, and advanced TNM (tumor-node-metastases) stage in human cancers. CONCLUSION: There is a significant correlation between up-regulation of GHET1 and both poor prognosis and advanced clinicopathological cancer characteristics. GHET1 may be a potential prognostic predictor for human cancers.

Knockdown of long non-coding RNA GHET1 suppresses cervical carcinoma in vitro and in vivo.

INTRODUCTION: The present study evaluated the effects of the long non-coding RNA (lncRNA) gastric carcinoma high-expressed transcript (GHET1) in cervical carcinoma development. METHODS: The expression levels of GHET1 and PTEN were measured using in situ hybridisation, immunohistochemistry (IHC) and quantitative reverse transcription PCR assay to investigate their correlations. In an in vitro study, the effects of GHET1 knockdown on the biological activities of SiHa and HeLa cells were evaluated by MTT, flow cytometry, transwell and wound-healing assays and relative protein expression was measured using western blotting. In an in vivo experiment, cell apoptosis and relative protein expression were measured in nude mice using TUNEL and IHC assays, respectively. RESULTS: The expression levels of lncRNA GHET1 and PTEN protein differed significantly between cancer and adjacent normal tissues (P< 0.05) and were negatively correlated in the clinical data. In vitro, proliferation rateswere significantly down-regulated in SiHa and HeLa cells. The GHET1 knockdown (si-GHET1) groups showed significantly higher G1 phase and apoptosis rates and significantly suppressed invasion and migration abilities compared with the normal control (NC) group (P< 0.05 for all). The expression levels of PTEN, PI3 K, AKT, P53, matrix metalloproteinase (MMP)-2 and MMP-9 proteins differed significantly between the si-GHET1 and NC groups (P< 0.05 for all). In vitro, the lncRNA group showed significantly suppressed tumour volume and weight, increased cell apoptosis and different relative protein expression levels compared with the NC group (P< 0.05 for all). CONCLUSION: GHET1 knockdown suppressed cervical carcinoma development via the PTEN/PI3 K/AKT signalling pathway.

Expression analysis of a panel of long non-coding RNAs (lncRNAs) revealed their potential as diagnostic biomarkers in bladder cancer.

INTRODUCTION: Long non-coding RNAs (lncRNAs) have fundamental roles in cell migration, proliferation, invasion and metastasis. METHODS: In the current study, we evaluated expression of a panel of lncRNAs in bladder cancer tissues, adjacent non-cancerous tissues (ANCTs) and normal bladder tissues to evaluate their diagnostic power. RESULTS: PV1 was down-regulated in tumor tissues compared with both ANCTs and normal controls (Expression ratios of 0.48 and 0.14; P values of 0.4 and <0.001 respectively). HOTAIR, NEAT1, TUG1 and FAS-AS1 were significantly down-regulated in tumor tissues compared with normal controls (Expression ratios of 0.4, 0.68, 0.54 and 0.11; P values of 0.04, 0.02, 0.02 and <0.001 respectively). CONCLUSION: Combination of transcript levels of seven lncRNAs improved both sensitivity and specificity values to 100%. The current study shows dysregulation of lncRNAs in bladder cancer and implies their role as diagnostic markers in this malignancy.

LncRNA GHET1 promotes cervical cancer progression through regulating AKT/mTOR and Wnt/ß-catenin signaling pathways.

Cervical cancer (CC) is a prevalent gynecological cancer, and the patients with CC usually suffer from dismal prognosis. Long non-coding RNAs (lncRNAs) are demonstrated to serve as promising biological targets in human cancers. Gastric carcinoma proliferation enhancing transcript 1 (GHET1) has been revealed to function as an oncogene in several cancers, but it has never been investigated in CC. We proposed to examine the biological role of GHET1 in CC and the underlying mechanism and validated the up-regulated expression of GHET1 in CC cell lines. Loss-of-function assays demonstrated that down-regulation of GHET1 inhibited cell growth, migration and epithelial-to-mesenchymal transition (EMT) in CC. Furthermore, we validated that GHET1 down-regulation could inactivate AKT/mTOR and Wnt/ß-catenin pathways, and that respective activation of these two pathways abrogated the inhibitive effect of GHET1 knockdown on CC cell growth, migration and EMT. Moreover, we unfolded a preliminary investigation on the modulation of GHET1 on AKT/mTOR and Wnt/ß-catenin pathways. We found that GHET1 stabilized E2F6 mRNA through interacting with IGF2BP2, so as to regulate the activity of AKT/mTOR and Wnt/ß-catenin pathways. Rescue assays also proved that GHET1 regulated these two pathways and CC cell growth, migration and EMT through E2F6. In conclusion, we revealed that down-regulation of GHET1 suppresses cervical cancer progression through regulating AKT/mTOR and Wnt/ß-catenin signaling pathways, indicating GHET1 as a promising molecular biomarker for CC treatment improvement.

The Expression of CCAT2, UCA1, PANDA and GHET1 Long Non-coding RNAs in Lung Cancer.

BACKGROUND: Long non-coding RNAs (lncRNAs) have been considered to be prospective biomarkers for diagnosing lung cancer due to the fundamental roles they hold in the regulating several cancer-related pathways. METHODS: Using the quantitative real-time polymerase chain reaction method, we evaluated the expression of CCAT2, UCA1, PANDA and GHET1 lncRNAs in 32 lung cancer tissue samples and their corresponding adjacent non-cancerous tissues (ANCTs) from lung cancer patients admitted to the Labbafi-Nejad Hospital from 2015 to 2016. RESULTS: No significant differences were found in the expression of lncRNAs within the tumoral and non-tumoral tissue samples. Bayesian Multilevel analysis showed no association between the expression of lncRNAs and the patient's tumor node metastasis (TNM) stage following adjustments for age. Spearman correlation analysis revealed an inverse correlation between the expression of PANDA in tumoral tissues and age. Additionally, the difference in CCAT2 expression among the tumoral and non-tumoral tissues was inversely correlated with patients' age. Significant pairwise correlations were found between the expression of lncRNAs in both the tumoral and non-tumoral tissues. CONCLUSION: Despite the findings supporting a role for the lncRNAs, CCAT2, UCA1, PANDA and GHET1 in the pathogenesis of lung cancer, our data suggests no relationship for expression of these lncRNAs in lung cancer, questioning their potential as lung cancer biomarkers.

Overexpression of LncRNA GHET1 predicts an unfavourable survival and clinical parameters of patients in various cancers.

Recently, increasing studies have reported that long non-coding RNA (lncRNA) gastric carcinoma highly expressed transcript 1 (GHET1) is highly expressed in variety of cancers and relevant to poor prognosis of cancer patients. Nevertheless, the results were inconsistent and the systematic analysis of lncRNA GHET1 in cancers has not been inspected. Thus, we aim to evaluate the relationship between lncRNA GHET1 expression and clinical outcomes in human cancers. We searched keywords in PubMed, Web of Science, Embase, Cochrane Library and ClinicalTrial.gov. Stata SE12.0 software was used in the quantitative meta-analysis. Pooled hazard ratio (HR) and odds ratio with 95% confidence interval (95% Cl) were calculated to evaluate the clinical significance of lncRNA GHET1. Twelve studies totalling 761 patients with cancers were included for analysis. The pooled results of this study indicated that high lncRNA GHET1 expression level was significantly associated with poor overall survival (OS, HR = 2.30, 95% CI: 1.75-3.02) in human cancers. The statistical significance was also detected in subgroup analysis stratified by analysis method, cancer type, sample size and follow-up time respectively. In addition, the elevated lncRNA GHET1 expression was also significantly related to more advanced clinical stage, earlier lymph node metastasis, earlier distant metastasis and bigger tumour size. LncRNA GHET1 may serve as a promising biomarker for prognosis in Asians with cancers.

Prognostic significance of LncRNA GHET1 expression in various cancers: a systematic review and meta-analysis.

BACKGROUND: Dysregulated expression of long non-coding RNA gastric carcinoma high expressed transcript 1 (lncRNA GHET1) has been observed in several cancers, however, definite conclusion on the prognostic value of lncRNA GHET1 expression in human cancers has not been determined. The aim of this meta-analysis was to evaluate the prognostic significance of lncRNA GHET1 expression in cancers. METHODS: PubMed, Web of Science and Embase were comprehensively searched for relevant studies. Meta-analyses of overall survival (OS) and clinicopathological features were conducted. RESULTS: Ten studies were finally analyzed in the present study. High lncRNA GHET1 expression was associated with shorter OS than low lncRNA GHET1 expression in cancers (hazard ratio (HR) = 2.59, 95% CI = 1.93-3.47, P<0.01). Online cross-validation using The Cancer Genome Atlas (TCGA) data observed similar results (HR = 1.10, P<0.05). When compared with low lncRNA GHET1 expression, high lncRNA GHET1 expression was related to larger tumor size (P<0.01), worse differentiation (P<0.01), earlier distant metastasis (P=0.02), earlier lymph node metastasis (P<0.01) and more advanced clinical stage (P<0.01). CONCLUSION: High lncRNA GHET1 expression is associated with worse cancer prognosis and can serve as a promising prognostic factor of human cancers.

Long non-coding RNA GHET1 contributes to chemotherapeutic resistance to Gemcitabine in bladder cancer.

PURPOSE: Bladder cancer (BC) ranks first in the incidence of urogenital tumors in China and second only to prostate cancer in the West. This study will clarify the roles and mechanism of lncRNA GHET1 in chemotherapeutic resistance of BC to Gemcitabine. METHODS: The expression of GHET1 was examined using real-time quantitative PCR. Cell Counting Kit-8 assay was applied to analyze cell proliferation and Gemcitabine sensitivity. Cell apoptosis was detected using Annexin V-FITC/PI double-stained flow cytometry. The expression of ABCC1 protein was examined using Western blotting. RESULTS: Firstly, the expression of GHET1 was up-regulated in BC, its high expression was relevant to high grade and muscle invasion of BC patients. Secondly, high expression of GHET1 was related to low Gemcitabine sensitivity of BC patients, and GHET1 was highly expressed in Gemcitabine-resistant BC cell lines. Thirdly, knockdown of GHET1 decreased the IC50 of Gemcitabine in Gemcitabine-resistant BC cell lines and advanced the Gemcitabine-induced cytotoxicity; GHET1 promoted Gemcitabine resistance in BC. Finally, knockdown of GHET1 also inhibited the expression of ABCC1 protein in Gemcitabine-resistant BC cells. CONCLUSIONS: High expression of GHET1 was related with the low sensitivity to Gemcitabine of BC; GHET1 contributed to chemotherapeutic resistance to Gemcitabine in BC through up-regulating ABCC1 expression. Our findings are helpful to expound the molecular mechanism of chemotherapeutic resistance in BC.

Long non-coding RNA GEHT1 promoted the proliferation of ovarian cancer cells via modulating the protein stability of HIF1α.

Cancer cells preferentially metabolize glucose via the aerobic glycolysis pathway, which is also named as Warburg effect. Increasing evidence has suggested that suppression of glycolysis inhibits the progression of cancers. In the present study, we found that the long non-coding RNA gastric carcinoma high expressed transcript 1 (GHET1) was overexpressed in ovarian cancer tissues and cell lines. Up-regulation of GHET1 was positively correlated with the tumor size and metastasis of the ovarian cancer patients. Overexpression of GEHT1 significantly promoted the proliferation and colony formation of ovarian cancer cells. Mechanistically, the candidate binding partners of GHET1 were explored by pull-down and mass spectrum. Of note, GHET1 was found to interact with the E3 ubiquitin ligase von Hippel-Lindau (VHL), which consequently blocked VHL-mediated degradation of hypoxia-inducible factor-1α (HIF1α) and enhanced the protein level of HIF1α in ovarian cancer cells. The up-regulated HIF1α promoted the glucose uptake and lactate generation of ovarian cancer cells. Collectively, our results suggested the oncogenic function of GHET1 via up-regulating the glycolysis in ovarian cancer and can be considered as a promising anti-cancer target.

GHET1 acts as a prognostic indicator and functions as an oncogenic lncRNA in cervical cancer.

Gastric carcinoma proliferation enhancing transcript 1 (GHET1) has been suggested to serve as a promising oncogenic lncRNA in various types of human cancer. However, the role of GHET1 remained unknown in cervical cancer. In our study, we found GHET1 expression was markedly elevated in cervical cancer tissue specimens and cell lines compared with adjacent normal cervical tissue specimens and human normal cervical cell line, respectively. Then, we found high expression of GHET1 is a useful biomarker to discriminate cervical cancer tissues from non-tumorous tissues, and associated with advanced clinical stage, lymph node metastasis, distant metastasis and poor histological grade in cervical cancer patients. The survival analysis showed high GHET1 expression was an independent unfavorable prognostic factor in cervical cancer patients. Knockdown of GHET1 expression markedly inhibits cervical cancer cell proliferation, migration, and invasion. The loss-of-function study indicated knockdown of GHET1 expression markedly inhibits cervical cancer cell proliferation, migration, and invasion. In conclusion, GHET1 acts as an oncogenic lncRNA in cervical cancer.

lncRNA GHET1 knockdown suppresses breast cancer activity in vitro and in vivo.

Long non-coding RNA gastric carcinoma high-expressed transcript 1 (lncRNA GHET1) is highly expressed in many tumors. The aim of the present study was to determine whether GHET1 inhibition decreases growth and metastasis of MCF-7 breast cancer cells by modulating epidermal growth factor receptor (EGFR) expression. In vitro, lncRNA GHET1 knockdown suppressed cell proliferation, migration, and invasion and enhanced cell apoptosis by maintaining MCF-7 cells in the G1 phase of the cell cycle. Furthermore, lncRNA GHET1 knockdown reduced the expression of EGFR and related proteins. Treatment of mice with a GHET1 inhibitor prevented tumor growth in vivo. The results indicate that lncRNA GHET1 inhibition directly suppresses EGFR expression, significantly inhibiting the downstream PI3K/AKT/Cyclin D1/MMP2/9 pathway. This mechanism may underlie the suppression of breast cancer cell activities including proliferation, migration, and invasion. In conclusion, lncRNA GHET1 knockdown suppresses tumor growth and metastasis by suppressing the activity of EGFR and downstream pathways.