lncRNA XIST通过调控miR-337-3p/HOXC8 轴促进胃癌的发展进程

[摘要] 目的：探讨lncRNA XIST（XIST）通过调控miR-337-3p/HOXC8 分子轴介导胃癌发展进程的分子机制。方法：选取2013 年3 月至2018 年1 月河北省唐山市开滦总医院普通外科手术切除的58 例胃癌组织和对应的癌旁组织标本,以及人胃癌细胞系AGS、MGC803、HGC27 和人胃黏膜细胞GES-1,用qPCR检测胃癌组织和细胞系中XIST 和miR-337-3p 的表达水平。将XIST敲降载体、miR-337-3p mimics/inhibitor 和HOXC8 过表达载体转染进AGS细胞,用CCK-8、Transwell 实验检测AGS细胞的增殖及侵袭能力,用WB检测HOXC8 及上皮钙黏蛋白（E-cadherin）、神经钙黏蛋白（N-cadherin）和波形蛋白（vimentin）的表达水平。用双荧光素酶报告基因验证XIST、miR-337-3p 和HOXC8 的靶向关系。结果：XIST在胃癌组织和细胞系中高表达（均P<0.01）。敲降XIST 显著抑制AGS细胞的增殖、侵袭和EMT（P<0.05 或P<0.01）。XIST 靶向作用miR-337-3p 并下调其表达,HOXC8 是miR-337-3p 的靶基因。敲降XIST 通过靶向上调miR-337-3p 对HOXC8 表达的抑制作用,从而抑制AGS细胞增殖、侵袭和EMT（P<0.05 或P<0.01）。结论：敲降XIST 可抑制AGS 细胞增殖、侵袭和EMT,其作用机制是通过靶向miR-337-3p 并下调HOXC8的表达。     

Loss of has-miR-337-3p expression is associated with lymph node metastasis of human gastric cancer

Background

Metastasis is the major cause of cancer-related death in patients with gastric cancer, and aberrant expression of various microRNAs (miRNAs) is associated with cancer metastasis.

Methods

Profiling of differentially expressed miRNAs was performed in three cases of primary gastric cancer and the corresponding metastatic lymph node tissues. Then, the five most altered miRNAs were further verified in 16 paired samples. Two of these five miRNAs were further assessed for their effects on the regulation of gastric cancer cell growth and invasion.

Results

The miRNA profile data showed 151 upregulated miRNAs (≥ 1.5-fold) and 285 downregulated miRNAs (≤ 0.67-fold) in the metastatic tissues compared to the primary gastric cancer tissues. Among these five miRNAs (i.e., hsa-miR-508-5p, hsa-miR-30c, hsa-miR-337-3p, hsa-miR-483-5p, and hsa-miR-134), expression of hsa-miR-337-3p and hsa-miR-134 was significantly downregulated in these 16 lymph node metastatic tissues compared to their primary tumor tissues (P<0.05) and in nine gastric cancer cell lines compared to the nonmalignant GES cell line. Furthermore, induction of hsa-miR-134 or hsa-miR-337-3p expression did not dramatically affect gastric cancer cell proliferation, but transfection of the hsa-miR-337-3p mimic did reduce gastric cancer cell invasion capacity.

Conclusions

These findings indicate that hsa-miR-337-3p plays a role in the reduction of gastric cancer cell invasion capacity, and further studies on the mechanism of hsa-miR-337-3p in gastric cancer metastasis are warranted.     

LncRNA POT1-AS1 accelerates the progression of gastric cancer by serving as a competing endogenous RNA of microRNA-497-5p to increase PDK3 expression

BackgroundGastric cancer (GC) is the most common malignant tumor of the digestive system. Although progress has been reported in terms of treatment, it is still the second leading cause of cancer-related death. Long non-coding RNAs have been shown to play a key role in human cancers in recent investigations. However, the role of POT1-AS1 in GC is still unclear.MethodsThe relative POT1-AS1 level in GC tissues and paracancerous tissues was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The biological function of POT1-AS1 was studied by CCK8 and Transwell assays in vitro experiments. Moreover, the downstream target genes of POT1-AS1 were predicted by bioinformatics.ResultsIn this study, high POT1-AS1 expression in GC cells was confirmed, and its elevated expression was linked to patients’ negative clinicopathological characteristics, as well as shorter disease-free survival (DFS) and overall survival (OS). POT1-AS1 was shown to serve as a competing endogenous RNA (ceRNA) by sponging miR-497-5p to increase PDK3 expression. The impact of POT1-AS1 silencing on GC malignant phenotypes could be reversed by suppressing miR-497-5p or restoring PDK3, according to rescue experiments.ConclusionsIn brief, POT1-AS1 acted as an oncogenic lncRNA in GC, facilitating GC development by affecting the miR-497-5p/PDK3 axis, implying that the POT1-AS1/miR-497-5p/PDK3 axis is a useful target in anticancer therapy.     

LINC00488 stimulates the progression of esophageal cancer by targeting microRNA-485-5p

Esophageal cancer is the eighth most prevalent malignancy in the world and China has a high incidence of esophageal cancer. Previous studies have identified that LINC00488 is an oncogene; however, its role in esophageal cancer remains unclear. The present study detected the expression and biological functions of LINC00488 in the progression of esophageal cancer. LINC00488 levels in 45 esophageal cancer and matched paracancerous tissues were detected. The association between LINC00488 level, clinical indexes and overall survival rate of patients with esophageal cancer was analyzed. Using Cell Counting Kit-8, Transwell and wound healing assays, the influence of LINC00488 on the biological functions of OE19 and OE33 cells were assessed. The target gene of LINC00488, microRNA-485-5p (miRNA-485-5p), was predicted using bioinformatics databases. In addition, the role of miRNA-485-5p in the progression of esophageal cancer was evaluated using rescue experiments. LINC00488 was upregulated in esophageal cancer tissues and cell lines. A high level of LINC00488 was associated with lymphatic and distant metastasis and poor prognosis in patients with esophageal cancer. Silencing LINC00488 attenuated the viability, migration and wound healing of OE19 and OE33 cells. miRNA-485-5p was downregulated in esophageal cancer and low expression levels predicted a poor prognosis in these patients. In addition, miRNA-485-5p level was negatively correlated with that of LINC00488. Rescue experiments showed that knockdown of miRNA-485-5p reversed the attenuated proliferation and migration of esophageal cancer cells with LINC00488-knockdown. In conclusion, LINC00488 aggravated the malignant progression of esophageal cancer by targeting miRNA-485-5p.     

MicroRNA-324-3p inhibits osteosarcoma progression by suppressing PGAM1-mediated aerobic glycolysis

Osteosarcoma (OS) is the most common primary malignant neoplasm of the bone. Recent studies have indicated that the inhibitory effects of microRNA (miR)-324-3p could affect the development of numerous cancers. However, its biological roles and underlying mechanisms in OS progression remain unexplored. In this study, miR-324-3p expression was markedly reduced in OS cell lines and tissues. Functionally, miR-324-3p overexpression suppressed OS progression and was involved in the Warburg effect. Mechanistically, miR-324-3p negatively regulated phosphoglycerate mutase 1 (PGAM1) expression by targeting its 3′-UTR. Moreover, high expression of PGAM1 promoted OS progression and aerobic glycolysis, which were associated with inferior overall survival in patients with OS. Notably, the tumor suppressor functions of miR-324-3p were partially recovered by PGAM1 overexpression. In summary, the miR-324-3p/PGAM1 axis plays an important role in regulating OS progression by controlling the Warburg effect. Our results provide mechanistic insights into the function of miR-324-3p in glucose metabolism and subsequently on the progression of OS. Targeting the miR-324-3p/PGAM1 axis could be a promising molecular strategy for the treatment of OS.     

MicroRNA-545-5p regulates apoptosis,migration and invasion of osteosarcoma by targeting dimethyladenosine transferase 1

The metastasis of osteosarcoma is a major threat to both adolescents and young adults. Identifying novel targets that may prevent osteosarcoma metastasis is critical in developing advanced clinical therapies for treating this cancer. The present study aimed to explore the mechanism of microRNA (miR)-545-5p in the metastasis of osteosarcoma. The present study identified miR-545-5p as a potential target that was downregulated in both osteosarcoma clinical samples and cell lines, and in the latter, ectopically expressed miR-545-5p caused apoptosis. In addition, miR-545-5p exerted inhibitory effects in osteosarcoma migration and invasion. Overexpression of miR-545-5p induced xenograft growth inhibition in vivo. In addition, miR-545-5p targeted dimethyladenosine transferase 1 (DIMT1), an oncogenic protein that facilitates osteosarcoma proliferation, migration and invasion. Taken together, the results of the present study suggest that miR-545-5p functions as a tumor suppressor in osteosarcoma that promotes apoptosis, while inhibiting migration and invasion by targeting DIMT1. Taken together, the results of the present study suggest two potential novel targets for osteosarcoma treatment and metastasis prevention.