Growth inhibitory effects of three miR-129 family members on gastric cancer

Reduced expression of microRNA-129 (miR-129) has been reported in several types of tumor cell lines as well as in primary tumor tissues. However, little is known about how miR-129 affects cell proliferation in gastric cancer. Here, we show that all miR-129 family members, miR-129-1-3p, miR-129-2-3p, and miR-129-5p, are down-regulated in gastric cancer cell lines compared with normal gastric epithelial cells. Furthermore, using the real-time cell analyzer assay to observe the growth effects of miR-129 on gastric cancer cells, we found that all three mature products of miR-129 showed tumor suppressor activities. To elucidate the molecular mechanisms underlying down-regulation of miR-129 in gastric cancer, we analyzed the effects of miR-129 mimics on the cell cycle. We found that increased miR-129 levels in gastric cancer cells resulted in significant G₀/G₁ phase arrest. Interestingly, we showed that cyclin dependent kinase 6 (CDK6), a cell cycle-associated protein involved in G₁-S transition, was a target of miR-129. We also found that expression of the sex determining region Y-box 4 (SOX4) was inversely associated with that of miR-129-2-3p and miR-129-5p but not of miR-129-1-3p. Together, our data indicate that all miR-129 family members, not only miR-129-5p, as previously thought, play an important role in regulating cell proliferation in gastric cancer.     

Tumour-suppressive microRNA-424-5p directly targets CCNE1 as potential prognostic markers in epithelial ovarian cancer

An accumulated evidence supports that MicroRNAs (miRNAs) have shown a prominent role in pathological processes and different tumor onset. However, to date, the potential functional roles and molecular mechanisms by how microRNA-424-5p(miR-424-5p) affects cancer cell proliferation are greatly unclear, especially in epithelial ovarian cancer(EOC).In this study, we demonstrated that miR-424-5p was significantly down-regulated in EOC tissues and cell lines. The level of miR-424-5p was negatively correlated with tumor size, TNM stage, pathological grade, lymphatic metastasis of EOC. Restoring miR-424-5p expression in EOC cells dramatically suppressed cell proliferation and caused an accumulation of cells in G1 phase, and thus contributed to better prognosis of EOC patients. Mechanistically, miR-424-5p inhibits CCNE1 expression through targeting CCNE1 3′UTR, and subsequent arrest cell cycle in G1/G0 phase by inhibiting E2F1-pRb pathway. This study revealed functional and mechanistic links between miR-424-5p and CCNE1 in the progression of EOC and provide an important insight into that miR-424-5p may serve as a therapeutic target in EOC.     

microRNA-195 promotes apoptosis and suppresses tumorigenicity of human colorectal cancer cells

Deregulated microRNAs and their roles in cancer development have attracted much attention. In the present study, we analyzed the roles of miR-195 in colorectal cancer pathogenesis, as its participation in some other types of cancer has been suggested by previous reports. By comparing miR-195 expression in 81 human colorectal cancer tissues and matched non-neoplastic mucosa tissues, we found that miR-195 was downregulated in cancer tissues. And restoration of miR-195 in colorectal cancer cell lines HT29 and LoVo could reduce cell viability, promote cell apoptosis and suppress tumorigenicity. Moreover, important antiapoptotic Bcl-2 was identified to be directly targeted by miR-195, and miR-195 was further suggested to exert its proapoptotic function mainly through targeting Bcl-2 expression. Taken together, our study provides important roles of miR-195 in colorectal cancer pathogenesis and implicates its potential application in cancer therapy.     

Mir-378a-5p抑制鼻咽癌细胞系CNE-1 细胞增殖以及肿瘤生长的初步研究*

目的： MiR-378a-5p是一种被认为在多种肿瘤发生过程中具有抑制肿瘤生长的微小RNA。然而miR-378a-5p在鼻咽癌中的 作用尚未见报道。因此,本文旨在通过临床样本的miRNA 表达谱分析以及细胞学实验从而揭示miR-378a-5p在鼻咽癌肿瘤发生过程中的作用。方法与结果：我们通过生物信息学的方法获取了鼻咽癌临床样本中miR-378a-5p的表达信息并通过与正常组织的 对比发现miR-378a-5p在鼻咽癌肿瘤组织中表达水平显著降低（P<0.01）。其次,我们发现高表达miR-378a-5p的鼻咽癌CNE-1 细 胞增殖速度显著较对照组降低（约40%~50%）。克隆形成实验证实了瞬时转染miR-378a-5p的鼻咽癌CNE-1 细胞的克隆形成数 量显著减弱。我们通过将稳定表达miR-378a-5p的CNE-1 细胞注射到裸鼠体内形成移植瘤并记录肿瘤生长曲线,结果显示 miR-378a-5p高表达组的裸鼠移植瘤体积明显较对照组小约50%,肿瘤重量显著降低(对照组0.33 g,处理组0.15 g)。结论：本研究通过对临床样本的分析以及在细胞和动物水平的实验验证揭示了miR-378a-5p具有抑制鼻咽癌肿瘤细胞增殖和肿瘤生长的作用。     

microRNA-501-5p promotes cell proliferation and migration in gastric cancer by downregulating LPAR1

In spite of the achievement in treatment, the gastric cancer (GC) mortality still remains high. MicroRNAs (miRNAs) are a group of small noncoding RNAs that play a crucial part in tumor progression. In this study, we explored the expression and function of microRNA-501-5p (miR-501-5p) in GC cell lines. Quantitative real-time polymerase chain reaction assay results suggested that miR-501-5p was significantly upregulated in GC tissues and cell lines. And, the Cell Counting Kit-8 colony formation and cell migration assay results showed that the downregulation of miR-501-5p decreased GC cell proliferation and migration. Besides that, we found that GC cell cycle was arrested in G2 phase and cell apoptosis rate was increased by silencing the expression of miR-501-5p in GC cell lines using the flow cytometry. We also found that miR-501-5p could directly target lysophosphatidic acid receptor 1 (LPAR1) and negatively regulate LPAR1 expression in GC cell lines by performing dual-luciferase reporter gene assay and Western blot analysis. And, LPAR1 was significantly downregulated in GC tissues and inversely correlated with miR-501-5p expression. Furthermore, LPAR1 downregulation promoted cell proliferation and migration, which were attenuated by cotransfection of miR-501-5p inhibitor in GC cells. In conclusion, miR-501-5p can promote GC cell proliferation and migration by targeting and downregulating LPAR1. miR-501-5p/LPAR1 may become a potential therapeutic target for GC treatment.     

Knockdown of DGCR5 enhances the radiosensitivity of human laryngeal carcinoma cells via inducing miR-195

Long noncoding RNAs (lncRNAs) exert critical roles in the development of various cancers, including human laryngeal cancer. Radioresistance contributes to the predominant causes of laryngeal cancer recurrence after radiotherapy. The aim of our study was to investigate the association of dysregulated lncRNA and radiation resistance in human larynx squamous carcinoma. Here, we investigated the biological roles of lncRNA DiGeorge syndrome critical region gene 5 (DGCR5) in radioresistance of human laryngeal cancer. Two human larynx squamous carcinoma cell lines (Hep-2 and Hep-2R), with different radiosensitivities in vitro were used in the present study. We observed that DGCR5 was significantly upregulated in Hep-2R cells. Inhibition of DGCR5 by LV-shDGCR5 transfection restrained Hep-2R cell proliferation and sensitized cells to radiation. Reversely, overexpression of DGCR5 exhibited an opposite phenomenon in vitro. In addition, microRNA (miR)-195 was predicted as a direct downstream target of DGCR5. Dual-luciferase reporter and RNA immunoprecipitation assays verified the direct interaction between them. Meanwhile, miR-195 was observed to be reduced in Hep-2R cells and miR-195 mimics repressed Hep-2 cell growth. Moreover, radiosensitivity of Hep-2R cells was greatly enhanced by overexpression of miR-195, which could be reversed by upregulation of DGCR5. Finally, in vivo experiments were used to validate that knockdown of DGCR5 suppressed laryngeal carcinoma via targeting miR-195. In conclusion, we indicated that DGCR5 could contribute to the radioresistance of human laryngeal carcinoma cells via sponging miR-195.     

AIMP3 inhibits cell growth and metastasis of lung adenocarcinoma through activating a miR-96-5p-AIMP3-p53 axis

Aminoacyl-tRNA synthetase-interacting multifunctional protein-3 (AIMP3) is a tumour suppressor, however, the roles of AIMP3 in non-small cell lung cancer (NSCLC) are not explored yet. Here, we reported that AIMP3 significantly inhibited the cell growth and metastasis of NSCLC (lung adenocarcinoma) in vitro and in vivo. We have firstly identified that AIMP3 was down-regulated in human NSCLC tissues compared with adjacent normal lung tissues using immunohistochemistry and western blot assays. Overexpression of AIMP3 markedly suppressed the proliferation and migration of cancer cells in a p53-dependent manner. Furthermore, we observed that AIMP3 significantly suppressed tumour growth and metastasis of A549 cells in xenograft nude mice. Mechanically, we identified that AIMP3 was a direct target of miR-96-5p, and we also observed that there was a negative correlation between AIMP3 and miR-96-5p expression in paired NSCLC clinic samples. Ectopic miR-96-5p expression promoted the proliferation and migration of cancer cells in vitro and tumour growth and metastasis in vivo which partially depended on AIMP3. Taken together, our results demonstrated that the axis of miR-96-5p-AIMP3-p53 played an important role in lung adenocarcinoma, which may provide a new strategy for the diagnosis and treatment of NSCLC.     

microRNA-195 在棕榈酸诱导肝细胞L02 葡萄糖摄取障碍中的作用

目的:探究microRNA-195对棕榈酸诱导肝细胞L02葡萄糖摄取障碍中的影响及其作用机制。方法:体外培养人肝细胞L02,用不同浓度棕榈酸(0.6 mmol/L,1 mmol/L)诱导人肝细胞L02(10 h),显微镜观察其形态学变化。应用葡萄糖氧化酶法检测细胞培养液中剩余的葡萄糖含量,Real Time-PCR检测棕榈酸诱导肝细胞L02葡萄糖摄取障碍后microRNA-195(miR-195)表达变化,Real Time-PCR检测转染miR-195 mimics及miR-195 inhibitor后miR-195的表达水平,激光共聚焦检测转染效率,miR-195过表达或低表达后葡萄糖摄取的变化。结果:高浓度棕榈酸可诱导肝细胞L02葡萄糖摄取障碍,培养液上清糖浓度升高约2.5 mmol/L,miR-195表达量明显升高;转染miR-195 mimic后miR-195表达升高约200倍,转染miR-195 inhibitor后miR-195表达降低约40倍;过表达miR-195后细胞培养液上清中葡萄糖量升高2.5 mmol/L,即葡萄糖摄取降低;低表达miR-195后上清液中葡萄糖量降低约1 mmol/L,即葡萄糖摄取作用加强。结论:miR-195有可能参与调控肝细胞L02葡萄糖摄取障碍。     

Differential expression of miR-195 in esophageal squamous cell carcinoma and miR-195 expression inhibits tumor cell proliferation and invasion by targeting of Cdc42

MicroRNAs (miRNA) have played an important role in carcinogenesis. In this study, Agilent miRNA microarray was used to identify differentially expressed miRNAs in esophageal squamous cell carcinoma (ESCC) tissues and miR-195 was downregulated in ESCC compared with normal esophageal tissues. Moreover, Cdc42 was confirmed as target gene of miR-195. Ectopic expression of miR-195 in ESCC cells significantly downregulated Cdc42 by directly binding its 3′ untranslated regions, and induced G1 cell cycle arrest, leading to a significant decrease in cell growth, migration, and invasion in vitro. Therefore, our findings demonstrated that miR-195 may act as a tumor suppressor in ESCC by targeting Cdc42.     

Long noncoding RNA LINC00473 drives the progression of pancreatic cancer via upregulating programmed death-ligand 1 by sponging microRNA-195-5p

Pancreatic cancer (PC) is a great health burden to patients owing to its poor overall survival rate. Long noncoding RNAs (lncRNAs) interact with microRNAs (miRs) to participate in tumorigenesis. Therefore, we aim to uncover the role and related mechanism of LINC00473 in PC through the modulation of miR-195-5p and programmed death-ligand 1 (PD-L1). Increased LINC00473 and PD-L1 but declined miR-195-5p were determined in PC tissues and cell lines, and it was found that LINC00473 mainly situated in the cytoplasm. Also, miR-195-5p was verified to bind with both LINC00473 and PD-L1. Next, with the aim to examine the ability of LINC00473, miR-195-5p, and PD-L1 on the PC progression, the expression of LINC00473, miR-195-5p and PD-L1 were altered with mimics, inhibitors, overexpression vectors or siRNAs in PC cells and cocultured CD8⁺ T cells. It was demonstrated that LINC00473 sponged miR-195-5p to upregulate PD-L1 expression. More important, the obtained results revealed that LINC00473 silencing or miR-195-5p upregulation elevated the expression of Bcl-2 associated X protein (Bax), interferon (IFN)-γ, and interleukin (IL)-4 but reduced the expression of B-cell lymphoma-2 (Bcl-2), matrix metalloproteinase (MMP)-2, MMP-9, and IL-10, thus inducing the enhancement of the apoptosis as along with the inhibition of proliferation, invasion, and migration of the PC cells. LINC00473 silencing or miR-195-5p elevation activated the CD8⁺ T cells. Taken together, LINC00473 silencing blocked the PC progression through enhancing miR-195-5p-targeted downregulation of PD-L1. This finding offers new therapeutic options for treating this devastating disease.     

Long noncoding RNA LINC00629 restrains the progression of gastric cancer by upregulating AQP4 through competitively binding to miR-196b-5p

Gastric cancer continues to be a common cancer in the world with high incidence and mortality. Accumulating evidence has implicated long noncoding RNAs (lncRNAs) in gastric cancer progression. Here, this study identified the potential role of a novel lncRNA, LINC00629 in gastric cancer and to elucidate the underlying mechanism. Initially, microarray-based gene expression profiling of gastric cancer was employed to identify differentially expressed genes. Next, the expression of LINC00629, microRNA-196b-5p (miR-196b-5p) and aquaporin 4 (AQP4) in clinical gastric cancer tissues was determined and the cell line presenting with the lowest LINC00629 expression was selected. The interaction among LINC00629, miR-196b-5p, and AQP4 was identified. Expression of LINC00629, miR-196b-5p, and AQP4 in gastric cancer cells were altered and then biological behaviors of gastric cancer cells were assessed by 5-ethynyl-2′-deoxyuridine and Transwell assays. Tumor formation in vivo was evaluated in nude mice. In gastric cancer, expression of LINC00629 and AQP4 was downregulated, and expression of miR-196b-5p was upregulated. Proliferation, invasion, and migration of gastric cancer cells were reduced after overexpression of LINC00629. LINC00629 competitively bound to miR-196b-5p, while AQP4 was a target of miR-196b-5p. Either downregulating miR-196b-5p or upregulating AQP4 could restrain the development of gastric cancer in vitro. LINC00629 overexpression repressed the growth of transplanted tumors in vivo. Taken together, LINC00629 competitively bound to miR-196b-5p to upregulate AQP4 expression, thereby inhibiting gastric cancer progression. Therefore, understanding of this mechanism may help to improve gastric cancer treatment.     

MicroRNA-490-5p inhibits proliferation of bladder cancer by targeting c-Fos

MicroRNAs (miRNAs) are non-protein-coding sequences that play a crucial role in tumorigenesis by negatively regulating gene expression. Here, we found that miR-490-5p is down-regulated in human bladder cancer tissue and cell lines compared to normal adjacent tissue and a non-malignant cell line. To better characterize the function of miR-490-5p in bladder cancer, we over-expressed miR-490-5p in bladder cancer cell lines with chemically synthesized mimics. Enforced expression of miR-490-5p in bladder cancer cells significantly inhibited the cell proliferation via G1-phase arrest. Further studies found the decreased c-Fos expression at both mRNA and protein levels and Luciferase reporter assays demonstrated that c-Fos is a direct target of miR-490-5p in bladder cancer. These findings indicate miR-490-5p to be a novel tumor suppressor of bladder cancer cell proliferation through targeting c-Fos.     

LncRNA SNHG12 promotes tumorigenesis and metastasis in osteosarcoma by upregulating Notch2 by sponging miR-195-5p

Osteosarcoma is the most common primary malignant bone tumor and has a high fatality rate in children and adolescents. Recently, an increasing amount of evidence has demonstrated that lncRNAs have crucial roles in regulating biological characteristics in malignant tumors. Therefore, this research was carried out to uncover the biological function and the potential molecular mechanism of SNHG12 in osteosarcoma. In this study, we found that SNHG12 was significantly upregulated in both osteosarcoma tissues and cell lines and osteosarcoma patients with high levels of SNHG12 tended to have a poor prognosis. We evaluated the biological function of SNHG12 in 143B and U2OS cells and show that the downregulation of SNHG12 suppressed cell proliferation by blocking cell cycle progression at the G0/G1 phase and weakened cell invasion and migration abilities. Dual-luciferase reporter and RIP assays were conducted to confirm that SNHG12 functioned as a ceRNA, modulating the expression of Notch2 by sponging miR-195-5p in osteosarcoma. We further demonstrate that Notch2 played a crucial role in activating the Notch signaling pathway. In conclusion, SNHG12 might serve as a valuable biomarker and prognosis factor in osteosarcoma patients. The SNHG12/miR-195-5p/Notch2-Notch signaling pathway axis might become a novel therapeutic for osteosarcoma.     

MiR-378a-5p直接靶ZEB1向上调鼻咽癌CNE-1细胞E-cadherin表达*

目的： Mir-378a-5p是一种被发现多年的微小RNA,其在包括肺癌、结肠癌和乳腺癌等多种肿瘤中都被认为具有抑制肿瘤生 长的作用。Mir-378a-5p与细胞增殖的关系在多篇文章中已经有较为详细的阐述,然而,目前没有报道提及miR-378a-5p是否通过 作用于细胞迁移和细胞粘附途径从而达到抑制肿瘤生长的作用。方法与结果：在本研究中,我们通过wound healing 和trans-well 的方法发现在鼻咽癌细胞CNE-1 中过表达miR-378a-5p显著的抑制了细胞迁移以及细胞浸润的过程。通过免疫印迹方法,我们 揭示了细胞粘附因子E-cadherin在过表达miR-378a-5p后显著上调。通过生物信息学的方法,我们预测了miR-378a-5p的可能作 用靶点,并通过双荧光报告载体的方法证实了ZEB1是miR-378a-5p的直接靶点。结论：我们的研究提示了miR-378a-5p造成的E-cadherin 的上调是通过直接抑制E-cadherin的负调控因子ZEB1造成的。E-cadherin的上调不但影响了细胞的迁移和粘附,而且 通过间接阻断Wnt通路抑制了下游控制细胞增殖的基因表达。本研究为理解miR-378a-5p的肿瘤抑制作用提供了一个新的作用 机理。     

miR-9-5p靶向Ambra1促进舌癌细胞增殖

miRNAs在肿瘤中异常表达,且与肿瘤的发生发展密切相关。目前发现,miR-9-5p在肿瘤中可能发挥原癌或抑癌效应,功能尚未完全阐述清楚。本文拟探讨miR-9-5p在舌癌中的作用。前期研究中收集10例舌癌组织及配对的癌旁组织,实时荧光定量PCR技术检测后发现,miR-9-5p在舌癌组织中的表达量显著高于癌旁组织,且其在舌癌细胞中的表达量也明显高于正常舌上皮细胞。此外,在舌癌细胞Tca8113中过表达miR-9-5p显著增加细胞的增殖能力。生物信息学预测及双荧光素酶报告基因实验证实,miR-9-5p可直接结合在自噬/苄氯素1调节因子1（activating molecule in beclin1-regulated autophagy, Ambra1）的 3′-UTR区域,靶向抑制Ambra1表达。Western印迹结果证实过表达miR-9-5p降低Ambra1的表达,反之亦然。Ambra1在舌癌细胞中的表达量显著低于正常舌上皮细胞。BrdU实验证实在舌癌细胞SCC-25中过表达Ambra1可显著抑制其增殖能力;相反,使用siRNA技术沉默Ambra1能够显著促进Tca8113细胞的增殖。在干预miR-9-5p的细胞中同时干预Ambra1的表达,结果发现Ambra1可显著逆转miR-9-5p对舌癌细胞增殖的促进作用。总之,miR-9-5p在舌癌中可能发挥原癌基因样作用,通过直接靶向抑制Ambra1表达进而促进舌癌细胞发生增殖。