N6-methyladenosine-modified long non-coding RNA KIF9-AS1 promotes stemness and sorafenib resistance in hepatocellular carcinoma by upregulating SHOX2 expression

BACKGROUND Hepatocellular carcinoma(HCC)is a prevalent and aggressive tumor.Sorafenib is the first-line treatment for patients with advanced HCC,but resistance to sorafenib has become a significant challenge in this therapy.Cancer stem cells play a crucial role in sorafenib resistance in HCC.Our previous study revealed that the long non-coding RNA(lncRNA)KIF9-AS1 is an oncogenic gene in HCC.However,the role of KIF9-AS1 in drug resistance and cancer stemness in HCC remains unclear.Herein,we aimed to investigate the function and mechanism of the lncRNA KIF9-AS1 in cancer stemness and drug resistance in HCC.AIM To describe the role of the lncRNA KIF9-AS1 in cancer stemness and drug resistance in HCC and elucidate the underlying mechanism.METHODS Tumor tissue and adjacent non-cancerous tissue samples were collected from HCC patients.Sphere formation was quantified via a tumor sphere assay.Cell viability,proliferation,and apoptosis were evaluated via Cell Counting Kit-8,flow cytometry,and colony formation assays,respectively.The interactions between the lncRNA KIF9-AS1 and its downstream targets were confirmed via RNA immunoprecipitation and coimmunoprecipitation.The tumorigenic role of KIF9-AS1 was validated in a mouse model.RESULTS Compared with that in normal controls,the expression of the lncRNA KIF9-AS1 was upregulated in HCC tissues.Knockdown of KIF9-AS1 inhibited stemness and attenuated sorafenib resistance in HCC cells.Mechanistically,N6-methyladenosine modification mediated by methyltransferase-like 3/insulin-like growth factor 2 mRNA-binding protein 1 stabilized and increased the expression of KIF9-AS1.Additionally,KIF9-AS1 increased the stability and expression of short stature homeobox 2 by promoting ubiquitin-specific peptidase 1-induced deubiquitination.Furthermore,depletion of KIF9-AS1 alleviated sorafenib resistance in a xenograft mouse model of HCC.CONCLUSION The N6-methyladenosine-modified lncRNA KIF9-AS1 promoted stemness and sorafenib resistance in HCC by upregulating short stature homeobox 2 expression.

Long non-coding RNA GATA6-AS1 is mediated by N6-methyladenosine methylation and inhibits the proliferation and metastasis of gastric cancer

BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.

Basic Study Long non-coding RNA TP73-AS1 promotes pancreatic cancer growth and metastasis through miRNA-128-3p/GOLM1 axis

BACKGROUND Previous studies have suggested that long non-coding RNAs(lncRNA)TP73-AS1 is significantly upregulated in several cancers.However,the biological role and clinical significance of TP73-AS1 in pancreatic cancer(PC)remain unclear.AIM To investigate the role of TP73-AS1 in the growth and metastasis of PC.METHODS The expression of lncRNA TP73-AS1,miR-128-3p,and GOLM1 in PC tissues and cells was detected by quantitative real-time polymerase chain reaction.The bioinformatics prediction software ENCORI was used to predict the putative binding sites of miR-128-3p.The regulatory roles of TP73-AS1 and miR-128-3p in cell proliferation,migration,and invasion abilities were verified by Cell Counting Kit-8,wound-healing,and transwell assays,as well as flow cytometry and Western blot analysis.The interactions among TP73-AS1,miR-128-3p,and GOLM1 were explored by bioinformatics prediction,luciferase assay,and Western blot.RESULTS The expression of TP73-AS1 and miRNA-128-3p was dysregulated in PC tissues and cells.High TP73-AS1 expression was correlated with a poor prognosis.TP73-AS1 silencing inhibited PC cell proliferation,migration,and invasion in vitro as well as suppressed tumor growth in vivo.Mechanistically,TP73-AS1 was validated to promote PC progression through GOLM1 upregulation by competitively binding to miR-128-3p.CONCLUSION Our results demonstrated that TP73-AS1 promotes PC progression by regulating the miR-128-3p/GOLM1 axis,which might provide a potential treatment strategy for patients with PC.

lncRNA HOXC13-AS在宫颈癌组织中的表达及临床意义

目的:探究反义长链非编码RNA HOXC13-AS(lncRNA HOXC13-AS)在宫颈癌组织中的表达及其临床意义。方法:选取2012年9月至2014年5月本院进行手术切除的73例宫颈癌患者作为研究对象,将切除的癌组织作为试验组,同时取同一患者的癌旁(距肿瘤边缘>2 cm)组织作为对照组。用实时荧光定量PCR(qRT-PCR)检测lncRNA HOXC13-AS表达情况;分析lncRNA HOXC13-AS与宫颈癌病理特征的关系;分析lncRNA HOXC13-AS表达情况对宫颈癌患者5年生存情况的影响;Cox回归分析影响宫颈癌的预后因素。结果:试验组HOXC13蛋白阳性率明显高于对照组(P<0.05);试验组lncRNA HOXC13-AS表达明显高于对照组(P<0.05);宫颈癌患者癌组织中lncRNA HOXC13-AS表达与患者年龄、肿瘤直径、病理类型及分化程度无关(P>0.05),与淋巴结是否转移、肌层浸润深度和FIGO分期有关(P<0.05);绘制宫颈癌患者术后1~60个月生存曲线,lncRNA HOXC13-AS高表达者的5年生存率明显低于低表达者(P<0.05);Cox回归分析显示,lncRNA HOXC13-AS表达、淋巴结是否转移、肌层浸润深度和FIGO分期均是影响宫颈癌患者预后的危险因素(P<0.05),其中lncRNA HOXC13-AS表达是影响宫颈癌患者预后的独立危险因素(P<0.05)。结论:宫颈癌患者癌组织中lncRNA HOXC13-AS呈高表达,其表达水平与淋巴结是否转移、肌层浸润深度和FIGO分期有关,是影响患者预后的独立危险因素,与宫颈癌患者预后密切相关,有望成为宫颈癌的潜在治疗靶点。

LncRNA AFAP1-AS1 exhibits oncogenic characteristics and promotes gemcitabine-resistance of cervical cancer cells through miR-7-5p/EGFR axis

Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted therapy.In our study,the role of long non-coding RNA(lncRNA)AFAP1-AS1 in gemcitabine resistance and related mechanisms were explored in cervical cancer cells.Methods:Gemcitabine-resistant cervical cancer cell lines HT-3-Gem and SW756-Gem were constructed using the gemcitabine concentration gradient method.The overall survival rates and recurrence-free survival rates were evaluated by Kaplan-Meier analysis.The interaction was verified through a Dual-luciferase reporter gene assay and a Biotinylated RNA pull-down assay.Cell proliferation ability was assessed through methyl-thiazolyl-tetrazolium(MTT),soft agar,and colony formation experiments.Cell cycle and apoptosis were detected byflow cytometry.Results:Up-regulation of AFAP1-AS1 in cervical cancer predicted a poor prognosis.Besides,patients in the gemcitabine-resistance group had higher levels of AFAP1-AS1 than the gemcitabine-sensitive group.AFAP1-AS1 promoted tumor growth and induced gemcitabine tolerance of cervical cancer cells.In addition,AFAP1-AS1 mediated epidermal growth factor receptor(EGFR)expression by serving as a molecular sponge for microRNA-7a-5p(miR-7-5p).This present study also proved that the knockdown of EGFR or overexpression of miR-7a-5p abolished the accelerative role of AFAP1-AS1 overexpression in cancer progression and gemcitabine tolerance.Conclusions:In general,the AFAP1-AS1/miR-7-5p/EGFR axis was tightly related to the progression and gemcitabine tolerance of cervical cancer,providing potential targets for the management of cervical cancer.

Research on HOXA11-AS in Malignant Tumors

Long-chain non-coding RNA HOXA11 antisense RNA (HOXA11-AS) is a kind of lncRNA discovered in recent years. Long-chain non-coding RNA (LncRNA) is an important regulatory factor of protein-coding genes, especially the disorder of LncRNA in more and more diseases which are found, including cancer. HOXA11-AS was first discovered in mouse embryo cDNA library using probes, and then it was discovered by scholars and played an important role in human cervical cancer, gastric cancer, glioma and other malignant tumor cells. Overexpression of HOXA11-AS has been found to promote cell proliferation, migration and tumor invasion, and has a carcinogenic effect. HOXA11-AS can promote tumor proliferation, metastasis and other malignant biological behaviors by interacting with miRNA and EZH2 protein, and is considered to be carcinogenic lncRNA. The discovery of HOXA11-AS provides new ideas for tumor prevention and treatment.

长链非编码RNA HOXC13-AS在肝细胞癌中的表达及对细胞增殖、侵袭的影响

目的观察长链非编码RNA HOXC13反义RNA(RNA HOXC13-AS)在肝细胞癌中的表达,探讨其对肝癌细胞增殖和侵袭的影响。方法实时荧光定量PCR(qRT-PCR)检测肝癌细胞株及正常肝细胞株中HOXC13-AS相对表达水平。体外培养HepG2细胞,设置空白对照组(不转染)、LV-NC组(转染携带HOXC13-AS-NC慢病毒)、LV-HOXC13-AS-shRNA组(转染携带HOXC13-AS-shRNA慢病毒),CCK-8法检测各组细胞增殖情况,Transwell法及细胞划痕实验检测各组肝癌细胞侵袭及迁移能力,蛋白免疫印记(WB)法检测增殖与侵袭相关蛋白表达水平。结果与人正常肝细胞株L02(0.22±0.03)比较,肝癌细胞株HepG2(1.02±0.04)、SMMC-7721(0.71±0.03)、HUH7(0.59±0.03)、SNU-182(0.41±0.03)中HOXC13-AS的表达水平显著升高,差异均有统计学意义(均P<0.05),以肝癌细胞HepG2中HOXC13-AS相对表达水平最高。与空白对照组、LV-NC组比较,LV-HOXC13-AS-shRNA组中HepG2细胞增殖、迁移与侵袭能力及基质金属蛋白酶-2、Ki-67、细胞周期蛋白D1(Cyclin D1)相对表达水平明显降低,而组织金属蛋白酶抑制剂-2蛋白相对表达水平明显升高,差异均有统计学意义(均P<0.05)。结论HOXC13-AS在肝癌细胞中高表达,HOXC13-AS低表达可抑制HepG2细胞的增殖、侵袭。