TIGIT and PD-1 may serve as potential prognostic biomarkers for gastric cancer

Gastric Cancer (GC) is the fifth leading cause of cancer-related death in the world, and in urgent need of specific therapeutic targets to acquire prominent effectiveness. T-cell immunoglobulin and immunoreceptor tyrosine–based inhibitory motif (ITIM) domain (TIGIT) and programmed cell death protein 1 (PD-1) are identified to be abnormally overexpressed in various types of cancers including GC. This study aimed to investigate whether TIGIT and PD-1 could serve as potential prognostic biomarkers for GC. Firstly, TCGA GC dataset analysis and correlation analysis were utilized to inspect the relationship between expression of TIGIT, PD-1 and CD8 + T cells in GC and adjacent normal tissues. Then, flow cytometry was used to verify the data after collecting the peripheral blood, GC and adjacent normal tissues from 150 GC patients. Lastly, quantitative RT-PCR was performed to detect the expression of CD155, CD113, CD112 and TIGIT in six human GC cell lines and 631 GC patients in KM Plotter Database to conduct prognostic analysis. As results, we found that TIGIT and PD-1 were upregulated in GC tissues with high CD8 + T cells infiltration, while correlation analysis indicated they were in high-positive correlation. In addition, the flow cytometry analysis further showed that the high-expression of TIGIT in tumor microenvironment of GC could suppress the function of infiltrative CD8 + T cells, which leads to the escape of GC cells from immune killing. Furthermore, CD155 and CD112 were found abnormally upregulated in GC tissues and cell lines and the high expression of CD155, CD112 and TIGIT demonstrated poor prognosis results. In conclusion, these results provided potential therapeutic targets and prognostic biomarkers for treatment of GC in clinic.     

敲低长链非编码RNA AFAP1-AS1抑制TPC-1甲状腺乳头状癌细胞上皮间质转化及其侵袭和迁移

目的 检测甲状腺乳头状癌组织长链非编码RNA (lncRNA)肌动蛋白丝相关蛋白1反义RNA1(AFAP1-AS1)的表达,敲低TPC-1甲状腺乳头状癌细胞AFAP1-AS1,研究其对TPC-1细胞上皮间质转化(EMT)的影响及相关分子机制.方法 采用实时定量PCR检测60例甲状腺乳头状癌组织lncRNA AFAP1-...     

Long non-coding RNA DLGAP1-AS1 promotes the progression of gastric cancer via miR-515-5p/MARK4 axis

Long non-coding RNA (lncRNA) is an essential regulator of carcinogenesis and cancer progression. In the study, we explored the role of lncRNA DLGAP1-AS1 in gastric cancer (GC). qRT-PCR was carried out to detect DLGAP1-AS1 expression in GC tissues and cell lines. CCK-8 assay, EdU assay, and transwell experiments were employed to detect the malignant biological behaviors of GC cells with DLGAP1-AS1 knockdown or overexpression. Bioinformatics and dual-luciferase report assay were used to confirm the binding relationship between DLGAP1-AS1 and miR-515-5p. MARK4 expression was detected by western blot after DLGAP1-AS1/miR-515-5p was selectively regulated. DLGAP1-AS1 was up-regulated in GC tissues and cell lines, and its high expression was closely associated with larger tumor size, higher TNM stage, and lymph node metastasis. Furthermore, DLGAP1-AS1 overexpression enhanced cell proliferation, migration, and invasion, and miR-515-5p could reverse these effects. DLGAP1-AS1 participated in the regulation of the MARK4 signaling pathway by targeting miR-515-5p. DLGAP1-AS1 promoted GC progression through miR-515-5p/MARK4 signaling pathway.     

Long non-coding RNA OIP5-AS1 promotes cell proliferation and aerobic glycolysis in gastric cancer through sponging miR-186

IntroductionLong non-coding RNAs (lncRNAs) play vital roles in tumour initiation and progression. LncRNA OIP5-AS1 is a potential oncogene in many types of human malignancies, but its biological functions in gastric cancer (GC) remain to be further elucidated.Material and methodsThe expression levels of OIP5-AS1 and miR-186 in GC tissues and cell lines were detected by RT-qPCR analysis. CCK-8 assay and colony formation assay were performed to investigate the proliferation of GC cells in vitro, and a nude mouse tumour model was established to validate the role of OIP5-AS1 in GC tumorigenesis in vivo. The glucose consumption and lactate production of GC cells were detected by ELISA assay. Interaction between OIP5-AS1 and miR-186 was determined using dual luciferase reporter assay.ResultsThe results demonstrated that OIP5-AS1 was upregulated in GC tissues and cell lines and that its high expression was notably correlated with aggressive clinicopathological features of GC patients. Functionally, knockdown of OIP5-AS1 inhibited GC cell proliferation and enhanced cell apoptosis in vitro, and inhibited GC xenograft growth in vivo. In addition, knockdown of OIP5-AS1 reduced the glucose consumption and lactate production in GC cells. In particular, OIP5-AS1 may function as a ceRNA for miR-186, and inhibition of miR-186 blocks the effects of OIP5-AS1 knockdown on aerobic glycolysis in GC cells.ConclusionsAccordingly, our findings suggested that the OIP5-AS1/miR-186 axis might be considered as a potential therapeutic target for GC patients.     

Long non-coding RNA TP73-AS1 predicts poor prognosis and regulates cell proliferation and migration in cervical cancer

IntroductionCervical cancer is one of the most common malignant tumors in women, which seriously affects women’s health, especially in developing countries. This study aims to investigate novel molecular markers for poor prognosis of cervical cancer to achieve correct guidance of clinical treatment, accurate assessment of prognosis, and provide a new basis for the choice of reasonable treatment options for cervical cancer patients.Material and methodsQRT-PCR was employed to investigate the expression of lncRNA TP73-AS1 in cervical cancer tissues and cell lines. COX multivariate analysis showed the relationship between TP73-AS1 expression and clinicopathological features of patients with cervical cancer. Colony formation and MTT assay detected the effect of TP73-AS1 on proliferation of cervical cancer cells. The effect of TP73-AS1 on migration and invasion of cervical cancer cells was determined by the wound-healing assay and transwell assay. Western blot was performed to assess the expression of EMT markers.ResultsThis study showed that lncRNA TP73-AS1 was up-regulated in cervical cancer tissues and cell lines (p < 0.001), and high expression of TP73-AS1 could be considered as an independent prognostic factor (p < 0.05). Moreover, lncRNA TP73-AS1 promotes cervical cancer cell migration and invasion, and knockdown of TP73-AS1 inhibits the growth of cervical cancer cells (p < 0.001).ConclusionsOur results indicated that lncRNA TP73-AS1 was up-regulated in cervical cancer tissues and cell lines, predicting poor prognosis of cervical cancer and regulating cell proliferation and migration.     

Expression of long non-coding RNA ZEB1-AS1 in esophageal squamous cell carcinoma and its correlation with tumor progression and patient survival

Background: LncRNA ZEB1-AS1 has been identified as a tumor oncogene in hepatocellular carcinoma. However, the clinical significance in esophageal squamous cell carcinoma (ESCC) is still unknown. The aim of this study was to explore ZEB1-AS1 expression levels and evaluated its clinical significance in ESCC patients. Methods: LNCRNA ZEB1-AS1 expression was determined by quantitative real-time PCR (QRT-PCR) in 87 pairs of ESCC specimens and adjacent non-tumor tissues. Then, the association of ZEB1-AS1 expression with clinicopathological factors or survival of ESCC patients were determined. Results: LNCRNA ZEB1-AS1 was found up-regulated in ESCC tissues compared to adjacent non-tumor tissues. Increased lncRNA ZEB1-AS1 expression was significantly associated with tumor grade, depth of invasion, and lymph node metastasis. Kaplan-Meier analysis revealed that ESCC patients with high ZEB1-AS1 expression had a poorer overall survival and disease-free survival. Furthermore, multivariate analysis suggested that ZEB1-AS1 expression was identified as an independent prognostic factor in patients with ESCC. Conclusion: These results indicated that lncRNA ZEB1-AS1 was associated with tumor progression and could be an independent prognostic factor for ESCC patients.     

LncRNA TP73-AS1 accelerates tumor progression in gastric cancer through regulating miR-194-5p/SDAD1 axis

Background

Long noncoding RNAs (lncRNAs) have been considered as significant regulators in many cancer progression, such as proliferation, invasion and other path of evolution. Nevertheless, we have not had a grasp of the role of lncRNA TP73-AS1 in gastric cancer (GC).

Circular RNAs as diagnostic biomarkers in gastric cancer: A meta-analysis review

PurposeGastric cancer is a malignant tumor in the world and circRNA has a close connection with it. However, the effects of circRNA on gastric cancer is still not clear.MethodsA comprehensive search of PubMed, Web of Science and Embase for published experimental studies about circRNA from 2013 to June 2018 was conducted with two investigators. Diagnostic OR (DOR) was calculated to evaluate the diagnostic efficacy by STATA 12.0.ResultsTotal 11 studies were found, including 12 kinds of circRNAs, 11 in tissues, 5 in plasma, and all down regulated. The combined DOR and AUC (Area Under the Curve of Receiver Operating Characteristic) with their 95%CI were 8.778 [6.108, 12.614] and 0.81 [0.78, 0.84] respectively, indicating that circRNAs can reflect gastric cancer as well. Subgroup analysis revealed that circRNAs in plasma were higher than tissues as well as in subgroup with different sample sizes. We speculated that the heterogeneity of the literatures was mainly due to the different backgrounds of gastric cancer and the differences in experimental design and operation process. And the Deeks’ funnel map revealed there was no obvious public biasness in the literature.ConclusionCircRNAs have high sensitivity and specificity in the diagnosis of gastric cancer, and it may become an auxiliary diagnostic biomarker of gastric cancer.     

干扰长链非编码RNA MNX1-AS1对卵巢癌细胞的干样特性、氧化应激以及线粒体功能损伤的影响

目的：探讨干扰长链非编码RNA（lncRNA） MNX1-AS1对卵巢癌细胞的干样特性、氧化应激以及线粒体 功能损伤的影响。方法：将KOV3 细胞随机分组,进行处理及培养,RT-PCR 检测RNA MNX1-AS1 的表达,筛选 干扰效果最明显的序列;观察干细胞成球情况;免疫印迹检测干细胞标记物蛋白八聚体结合转录因子4（OCT4）、 性别决定区Y 框蛋白（SOX2）和ATP 结合转运蛋白G 超家族成员2（ABCG2）的表达;检测氧化应激标记物丙 二醛（MDA）、超氧化物歧化酶（SOD）的含量;荧光探针检测活性氧（ROS）的含量;流式细胞仪检测线粒体 膜电位的变化;免疫印迹检测B 淋巴细胞瘤-2 基因（Bcl-2）/Bcl-2 相关X蛋白（Bax）、活化胱天蛋白酶3（cleaved cas3）/cas3、c-Myc 的表达。结果：3 个序列对比显示MNX1-AS1-shRNA3 干扰组最为显著,选择此组为后续实 验干扰组,分组为对照组、阴性对照组（shRNA-NC）、干扰组（MNX1-AS1-shRNA3）;与对照组相比,MNX1- AS1-shRNA3 干扰组SKOV3 干细胞成球数量、直径减小,干细胞标记物蛋白OCT4、 SOX2、ABCG2 的表达显著 降低,SOD 活性、c-Myc 蛋白表达均显著降低,线粒体损伤标记物蛋白的表达（Bax/Bcl-2、cleaved cas3/cas3）、 MDA与ROS 含量均显著升高,线粒体的膜电位下降。结论：干扰lncRNA MNX1-AS1 诱导卵巢癌细胞的干样特 性降低、氧化应激增强、线粒体损伤加重,干扰lncRNA MNX1-AS1 对SKOV3 细胞抑制效果显著,具有靶向治 疗卵巢癌的潜力。     

Long non-coding RNA MSC-AS1 facilitates the proliferation and glycolysis of gastric cancer cells by regulating PFKFB3 expression

Long non-coding RNA musculin antisense RNA 1 (lncRNA MSC-AS1) has been recognized as an oncogene in pancreatic cancer, hepatocellular carcinoma, nasopharyngeal carcinoma, and renal cell carcinoma. However, the functional significance of MSC-AS1 and its underlying mechanism in gastric cancer (GC) progression remain unclear. In this study, we demonstrated that the expression of MSC-AS1 in GC tissues was significantly higher than that in non-tumor tissues. Moreover, the elevated level of MSC-AS1 was detected in GC cells (MKN-45, AGS, SGC-7901, and MGC-803) compared to normal GES-1 gastric mucosal cells. The cancer genome atlas (TCGA) data further indicated that the high level of MSC-AS1 was closely correlated with advanced tumor stage and poor prognosis of GC. Next, we revealed that MSC-AS1 knockdown inhibited the proliferation, glucose consumption, lactate production, and pyruvate production of MGC-803 cells. Conversely, MSC-AS1 overexpression enhanced the proliferation and glycolysis of AGC cells. Mechanistically, modulating MSC-AS1 level affected the expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), but did not impact the levels of hexokinase 2 (HK2) and pyruvate kinase M2 (PKM2) in GC cells. Based on this, we reversed the MSC-AS1 knockdown-induced the inhibition of cell proliferation and glycolysis by restoring PFKFB3 expression in MGC-803 cells. In conclusion, MSC-AS1 facilitated the proliferation and glycolysis of GC cells by maintaining PFKFB3 expression.     

A novel long non-coding RNA NFIA-AS1 is down-regulated in gastric cancer and inhibits proliferation of gastric cancer cells

Gastric cancer is one of the most common malignant gastrointestinal tumors whose morbidity and mortality account for the second and third place respectively in malignant tumors in China. As an important participant in tumor biology, the abnormal expression of long non-coding RNA (lncRNAs) in cancer cells is closely related to the occurrence and development of tumors and plays the role of oncogenes or tumor suppressor genes. In this study, we identified a novel lncRNA NFIA antisense RNA 1 (NFIA-AS1) and explored its role and clinical significance in gastric cancer. Real-time quantitative PCR was performed to detect the expression of NFIA-AS1 in tumor tissues and corresponding normal tissues from 42 pairs of gastric cancer samples. The lower expression of NFIA-AS1 was significantly associated with larger tumor size, lower histological grade, and advanced TNM stage. Kaplan-meier analysis showed that NFIA-AS1 expression could be used as an independent predictor of overall survival. We also demonstrated that overexpression of NFIA-AS1 significantly inhibited the proliferation of gastric cancer cells through affecting p16 levels. In conclusion, our results suggest that the lncRNA NFIA-AS1 may play the role of tumor suppressor gene, and serve as a biomarker for prognosis or progression of gastric cancer.     

Down-regulation of long non-coding RNA LET is associated with poor prognosis in gastric cancer

Introduction: Long non-coding RNAs (lncRNAs) have emerged recently as major players in tumor biology and may be used for cancer diagnosis, prognosis, and potential therapeutic targets. Although down-regulation of lncRNA LET in several cancers has been studied, its role in gastric cancer remains unknown. The aim of our study was to investigate the expression, and clinical significance of lncRNA LET in gastric cancer. Methods: The expression of lncRNA LET was detected by quantitative real-time PCR (qRT-PCR) in pairs of tumor tissues and adjacent non-tumor tissues of 93 gastric cancer patients. Then, we analyzed the potential relationship between lncRNA LET expression levels in tumor tissues and clinicopathological features of gastric cancer, and clinical outcome. Results: We found that lncRNA LET expression was markedly down-regulated in tumor tissues compared with adjacent non-tumor tissues, and associated with depth of invasion, lymph node metastasis, distant metastasis, and TNM stage. Kaplan-Meier analysis showed that patients with low lncRNA LET expression had a poor overall survival than those with high lncRNA LET expression. Moreover, univariate and multivariate analyses showed that low lncRNA LET expression was an independent poor prognostic factor for gastric cancer patients. Conclusions: Our data provided the first evidence that lncRNA LET might be a novel prognostic indicator in gastric cancer and might be a potential target for diagnosis and gene therapy.     

Long non-coding RNA CCAT2 is up-regulated in gastric cancer and associated with poor prognosis

Introduction: Dysregulation of long non-coding RNAs (lncRNAs) play important roles in tumor progression. The aim of our study was to explore the clinicopathologic and prognostic significance of lncRNA CCAT2 expression in human gastric cancer. Methods: Expression levels of lncRNA CCAT2 in 85 pairs of gastric cancer and adjacent non-tumor tissues were detected by quantitative real-time PCR (qRT-PCR). In order to determine its prognostic value, overall survival and progression-free survival were evaluated using the Kaplan-Meier method, and multivariate analysis was performed using the Cox proportional hazard analysis. Results: Expression levels of lncRNA CCAT2 in gastric cancer tissues were significantly higher than those in adjacent non-tumor tissues. By statistical analyses, high lncRNA CCAT2 expression was observed to be closely correlated with higher incidence of lymph node metastasis and distance metastasis. Moreover, patients with high lncRNA CCAT2 expression had shorter overall survival and progression-free survival compared with the low lncRNA CCAT2 group. Multivariate analyses indicated that high lncRNA CCAT2 expression was an independent poor prognostic factor for gastric cancer patients. Conclusions: Our results suggested that up-regulation of lncRNA CCAT2 was correlated with gastric cancer progression, and lncRNA CCAT2 might be a potential molecular biomarker for predicting the prognosis of patients.     

Prognostic value of long non-coding RNA FOXD2-AS1 expression in patients with solid tumors

BackgroundAlthough increasing evidence has revealed that FOXD2-AS1 overexpression exists in various solid tumors, the value of FOXD2-AS1 as a prognostic marker in such cancers remains uncertain. Accordingly, the present research aimed to assess the association of FOXD2-AS1 with cancer prognosis and predict the biological function of FOXD2-AS1.MethodsWe systematically retrieved PubMed, PMC, Web of Science, EMBASE and Wiley Online Library databases for eligible articles published up to December 2018. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated to evaluate the correlation of FOXD2-AS1 expression with overall survival (OS), disease free survival (DFS) and clinicopathological characteristics. We also used five Gene Expression Omnibus (GEO) datasets from breast cancer patients to explore the relationship between FOXD2-AS1 expression and prognosis. Finally, we validated FOXD2-AS1 expression in various carcinomas and predicted its biological function based on the public databases.ResultsA total of 13 studies with 2502 tumor patients were included. The pooled HRs demonstrated that FOXD2-AS1 overexpression was significantly associated with unfavorable OS (HR = 1.39, 95%CI: 1.23–1.57, p < 0.001) and DFS (HR = 2.24, 95%CI: 1.55–3.23, p < 0.001) in tumor patients. The pooled ORs indicated that FOXD2-AS1 upregulation was related to large tumor size (OR = 1.53, 95%CI: 1.26–1.85, p < 0.001), deep invasion depth (OR = 1.99, 95%CI: 1.53–2.58, p < 0.001), distant metastasis (OR = 2.03, 95%CI: 1.69–2.43, p < 0.001) and advanced TNM stage (OR = 1.35, 95%CI: 1.06–1.72, p = 0.0150), but not to lymph node metastasis nor differentiation. Moreover, a similar pooled result for the OS of breast cancer patients was obtained (HR = 1.55, 95%CI: 1.14–2.11, p = 0.0052) by analyzing GEO data. Finally, elevated FOXD2-AS1 expression in various solid tumor tissues was verified based on The Cancer Genome Atlas (TCGA) data. Further functional prediction demonstrated that FOXD2-AS1 may participate in some cancer-related pathways.ConclusionElevated FOXD2-AS1 expression was associated with poor survival in patients with solid tumors and may serve as a potential prognostic biomarker for a variety of cancers.     

Long noncoding RNA linc-UBC1 is negative prognostic factor and exhibits tumor pro-oncogenic activity in gastric cancer

Despite the advances in the management of gastric cancer, the prognosis of advanced gastric cancer remains relatively poor. Thus, it is of urgent need to identify novel prognostic markers and therapeutic targets of gastric cancer. A growing volume of literature has indicated that lncRNAs are differentially expressed in a diverse array of cancer and play an important role in the development of cancer. Linc-UBC1, a recently identified long noncoding RNA, was initially found to be upregulated in bladder cancer. However, the role of linc-UBC1 in gastric cancer remains to be elusive. In this study, we found that linc-UBC1 was significantly upregulated in gastric cancer tissues compared to adjacent normal tissues. Furthermore, high linc-UBC1 expression was associated with lymph-node metastasis, tumor size, TNM stage and poorer prognosis. Inhibition of linc-UBC1 suppressed the proliferation, motility and invasion of gastric cancer cells. Our study suggests that linc-UBC1 may represent a novel diagnostic, prognostic biomarker and a potential therapeutic target of gastric cancer.