长链非编码RNA Linc00152在泛癌中表达、预后及功能研究

目的 分析Linc00152在泛癌不同组织中表达差异及其表达情况与肿瘤的恶性程度及患者预后的关系,并探究Linc00152在不同类型癌细胞中相关功能。方法 选取33例乳腺标本进行RNA-Seq,用qPCR方法检测50对乳腺癌组织和正常组织Linc00152的表达,结合GEO和TCGA数据库,分析Linc00152表达与乳腺癌恶性程度及患者预后的相关性;分析Linc00152在不同类型癌症、不同分期和分级中的表达情况。采用MDA-MB-231乳腺癌细胞系、SGC-7901胃癌细胞系、786-O肾癌细胞系进行细胞增殖能力、细胞凋亡和细胞迁移侵袭能力检测。结果 Linc00152在乳腺癌组织高表达(P＜0.001),在HER2阳性和三阴性乳腺癌中Linc00152表达更高(P＜0.0001);Linc00152高表达的乳腺癌患者无事件生存期和无转移生存期较差(P＜0.001;P＜0.01);敲降Linc00152后细胞增殖、迁移、侵袭能力降低,细胞凋亡增加(P＜0.05)。结论 Linc00152在恶性肿瘤中具有促癌作用,可能是潜在的治疗靶点。     

The KRAS/Lin28B axis maintains stemness of pancreatic cancer cells via the let‐7i/TET3 pathway

Increasing evidence demonstrates that Lin28B plays critical roles in numerous biological processes including cell proliferation and stemness maintenance. However, the molecular mechanisms underlying Lin28B nuclear translocation remain poorly understood. Here, we found for the first time that KRAS promoted Lin28B nuclear translocation through PKCβ, which directly bound to and phosphorylated Lin28B at S243. Firstly, we observed that Lin28B was upregulated in pancreatic cancer, contributing to cellular migration and proliferation. Furthermore, nuclear Lin28B upregulated TET3 messenger RNA and protein levels by blocking the production of mature let‐7i. Subsequently, increased TET3 expression could also promote the expression of Lin28B, thereby forming a Lin28B/let‐7i/TET3 feedback loop. Our results suggest that the KRAS/Lin28B axis drives the let‐7i/TET3 pathway to maintain the stemness of pancreatic cancer cells. These findings illuminate the distinct mechanism of Lin28B nuclear translocation and its important roles in KRAS‐driven pancreatic cancer, and have important implications for development of novel therapeutic strategies for this cancer.

Abbreviations

CCK‐8

cell counting kit‐8

CSC

cancer stem cells

IP

immunoprecipitation

MUT

mutant type

NLS

nuclear localization signal

PC

pancreatic cancer

PCSC

pancreatic cancer stem cells

PKC

protein kinase C

WT

wild‐type

     

Linc00704对结直肠癌细胞增殖、迁移及侵袭的影响

目的 探讨Linc00704（long non-coding RNA 00704）对结直肠癌细胞增殖、迁移和侵袭能力的影响。方法 RT-qPCR检测配对结直肠癌及癌旁正常组织、结直肠癌细胞和正常永生化人结肠上皮细胞系FHC中Linc00704 mRNA的表达。反义寡核苷酸（antisenseoligonucleotide，ASO）转染结直肠癌细胞构建Linc00704低表达细胞模型，慢病毒感染结直肠癌细胞构建Linc00704过表达细胞模型，RT-qPCR检测转染效率；CCK-8实验检测细胞增殖能力，Transwell实验检测细胞迁移及侵袭能力。结果 相比癌旁组织，Linc00704在结直肠癌组织中表达降低（t=4.103，P<0.001）。8种结直肠癌细胞系中有6种细胞系（RKO、HCT15、NCI-H716、SW480、SW1463、SW48）Linc00704的表达较FHC细胞低（F=44.750，P<0.001）。沉默 Linc00704表达可促进Caco-2、DLD-1细胞迁移和侵袭能力（均P<0.01），但对增殖无明显影响（均P>0.05）。过表达Linc00704可抑制RKO、HCT15细胞迁移和侵袭能力（均P＜0.001），但对增殖无明显影响（均P>0.05）。结论 Linc00704在结直肠癌组织中呈低表达，过表达Linc00704可抑制结直肠癌细胞迁移和侵袭能力。     

Linc00052基因在非小细胞肺癌中的表达及临床意义

目的:探究非小细胞肺癌(NSCLC)组织及其细胞系内基因长链非编码RNA00052(long intergenic non-coding RNA 00052,Linc00052)的表达水平,以及Linc00052在肺癌中的临床意义、作用机制及与患者预后的相关性。方法:利用逆转录-聚合酶链反应(qRT-PCR)检测正常肺细胞系与肺癌细胞系之间Linc00052表达水平的差异,肺癌组织与癌旁组织之间Linc00052表达水平的差异,并分析Linc00052与肺癌临床病理特征的相关性,Kaplan-Meier生存曲线分析Linc00052与肺癌预后之间的相关性。在A549细胞系中过表达Linc00052,采用MTT实验检测过表达Linc00052前后细胞增殖变化,并采用qRT-PCR检测miR-330-3p表达变化。结果:肺癌细胞系较正常肺细胞系中Linc00052明显低表达,同时肺癌组织比癌旁组织中Linc00052明显低表达(P＜0.01);Linc00052的表达与肿瘤的分化程度（P=0.02）、淋巴结转移（P=0.002）、远处转移（P=0.005）和临床分期（P=0.001）有关。肺癌的Linc00052表达水平减低与肺癌患者的预后不良有关（P＜0.05）。过表达Linc00052后可显著抑制细胞增殖（P＜0.05）,qRT-PCR结果证实,过表达Linc00052可显著下调miR-330-3p mRNA的表达水平（P＜0.05）。结论:Linc00052在肺癌组织中表达下调,并与肺癌的发生发展及预后密切相关,Linc00052有可能通过负调控miR-330-3p在肺癌中发挥抑癌作用。     

miR-26a通过调控E2F7、Myc抑制乳腺癌MDA-MB-231细胞的增殖和迁移能力

目的:研究miR-26a对乳腺癌MDA-MB-231细胞增殖和迁移能力的影响,并分析miR-26a 调控增殖与迁移的可能机制。方法:应用实时荧光定量PCR法(QPCR)检测乳腺癌细胞系和正常乳腺上皮细胞中miR-26a的表达水平,并检测三阴型乳腺癌组织及相应正常乳腺组织中miR-26a与E2F7 mRNA的表达水平。应用脂质体介导的方法,以miR-26a mimics与E2F7 siRNA瞬时转染MDA-MB-231细胞,实时荧光定量PCR法检测miR-26a表达水平,Western blot法检测E2F7、Myc蛋白的表达水平。MTT法检测MDA-MB-231细胞的增殖能力,划痕实验检测MDA-MB-231细胞迁移能力。结果:乳腺癌细胞中miR-26a的表达水平均低于正常乳腺细胞MCF-10A,且三阴型乳腺癌细胞表达水平降低最明显。三阴型乳腺癌组织中miR-26a相对于正常乳腺组织表达减低,而E2F7 mRNA表达则显著升高。miR-26a mimics转染后miR-26a表达水平显著升高,miR-26a过表达可抑制E2F7、Myc蛋白的表达;E2F7 siRNA转染后E2F7表达水平减低,Myc蛋白表达亦减低。MTT实验结果示miR-26a过表达可抑制MDA-MB-231细胞增殖,划痕实验示miR-26a过表达可抑制乳腺癌MDA-MB-231细胞迁移能力。结论:miR-26a可能通过抑制E2F7、Myc调控乳腺癌MDA-MB-231细胞的增殖与迁移能力。     

Linc00460通过海绵吸附影响miR-320a对乳腺癌细胞的有氧糖酵解作用

目的 探讨Linc00460通过海绵吸附miR-320a对乳腺癌（BC）细胞有氧糖酵解作用的影响。方法 qRT-PCR法检测正常乳腺上皮细胞系MCF-10A及5种BC细胞系中Linc00460和miR-320a表达水平。qRT-PCR检测干扰Linc00460对miR-320a表达的影响,双荧光素酶报告基因实验检测miR-320a和Linc00460的靶向关系。将si-Linc00460和miR-320a inhibitor共转染至MDA-MB-231细胞,qRT-PCR检测细胞中miR-320a表达水平;MTT法检测细胞增殖能力;2-NBDG法检测细胞葡萄糖摄取率;比色法检测细胞上清液中乳酸含量;酶活性试剂盒检测糖酵解关键酶的活性;Western blot检测酵解途径中关键蛋白表达水平。结果 与MCF-10A细胞比较,5种BC细胞系中Linc00460高表达,而miR-320a低表达。干扰Linc00460后,MDA-MB-231细胞中miR-320a表达显著升高。双荧光素酶报告基因实验证实,miR-320a和Linc00460可靶向结合。干扰Linc00460表达后MDA-MB-231细胞增殖能力受到明显抑制（P=0.000）,细胞葡萄糖摄取率和细胞上清液中乳酸含量降低（均P=0.000）,PFK、PK和LDH酶活性受到抑制（均P=0.000）,PFKM、GLUT1和LDHA蛋白表达水平下调（均P=0.000）。抑制miR-320a可明显逆转si-Linc00460对MDA-MB-231细胞增殖和糖酵解的抑制作用（均P=0.000或0.001）。结论 Linc00460可能通过海绵吸附miR-320a,上调PFKM表达,从而促进BC细胞有氧糖酵解作用。     

Lin28-let7信号通路和下游靶基因在食管癌中的表达及其临床意义

目的：探讨Lin28-let7信号通路及靶基因在食管癌中的表达及对食管癌细胞体外增殖,侵袭能力的影响.方法：Real-time PCR检测42例食管癌及对应癌旁组织中Lin28和let-7基因mRNA的表达水平,分析两者表达的相关性.检测食管癌细胞系中Lin28和let7的表达水平.构建Lin28过表达载体转染食管癌细胞系,检测细胞增殖、迁移和侵袭能力的改变.利用Western blot检测Lin28-let7下游肿瘤相关靶基因的表达.结果：Lin28在食管癌组织中高表达,与let7的表达呈负相关.成功获得Lin28基因过表达的食管癌细胞系,机制研究显示Lin28-let7通过靶向k-ras和HMGA2基因的表达促进食管癌细胞系的体外增殖、迁移及侵袭能力.结论：食管癌中激活的Lin28-let7信号通路促进k-ras和HMGA2基因的表达,促进食管癌细胞的增殖和侵袭能力.     

Long noncoding RNA LINP1 acts as an oncogene and promotes chemoresistance in breast cancer

Recent studies have shown that long non-coding RNAs (lncRNAs) are involved in a number of biological processes; however, further study is still warranted to comprehensively reveal their functions. In this study, we showed that the lncRNA in non-homologous end joining (NHEJ) pathway 1 (LINP1) was related to breast cancer cell proliferation, metastasis and chemoresistance. Loss- and gain-of function studies were used to assess the role of LINP1 in promoting breast cancer progression. LINP1 knockdown mitigated breast cancer cell growth by inducing G1-phase cell cycle arrest and apoptosis. LINP1 also promoted breast cancer cell metastasis and influenced the expression of epithelial-mesenchymal transition-related markers. We identified p53 as a regulator of LINP1, and LINP1 overexpression could restore the metastatic effects of p53. Furthermore, LINP1 was upregulated in doxorubicin- and 5-fluorouracil-resistant cells and induced chemoresistance. We also observed that LINP1 enrichment played a critical functional role in chemoresistance by inhibiting chemotherapeutics-induced apoptosis. Moreover, LINP1 in tumors was associated with lower overall survival and disease-free survival. In conclusion, LINP1 may serve as a potential oncogene and chemoresistance-related regulator of breast cancer cells, suggesting that LINP1 might be a potent therapeutic target and might reduce chemoresistance in breast cancer.     

Linc00355在结肠癌中表达上调并促进肿瘤细胞增殖和侵袭

目的:探讨长链非编码RNA(long non-coding RNA,lncRNA)Linc00355在结肠癌组织中的表达水平,以及沉默Linc00355表达对结肠癌HCT116细胞增殖及迁移和侵袭能力的影响。方法:通过对肿瘤基因组图谱(The Cancer Genome Atlas,TCGA)和基因表达综合(Gene Expression Omnibus,GEO)数据库中lncRNA进行差异表达的分析,筛选出在结肠癌组织中差异表达的lncRNA。用Kaplan-Meier方法分析Linc00355表达水平与患者生存的相关性。通过共表达分析方法预测与Linc00355相关的mRNA,并进行基因本体(Gene Ontology,GO)功能富集分析。采用siRNA干扰技术沉默结肠癌HCT116细胞中Linc00355的表达水平,随后采用CCK-8法和平板克隆实验检测沉默Linc00355表达对HCT116细胞增殖能力的影响,Transwell小室实验检测对细胞的迁移及侵袭能力的影响。结果:Linc00355在结肠肿瘤组织中的表达水平显著上调(P<0.01),且Linc00355高表达与患者的总生存时间呈现明显的负相关(P<0.05);GO富集分析提示,Linc00355共表达mRNA与p53信号转导、蛋白质泛素化及细胞衰老等多个信号通路相关(P值均<0.05);沉默Linc00355后HCT116细胞的增殖、迁移及侵袭能力均明显降低(P值均<0.001)。结论:Linc00355在结肠癌患者中是一个不良的预后指标,Linc00355可能通过调控多个信号通路促进结肠癌的发生和发展。     

High expression of Lin28 is associated with tumour aggressiveness and poor prognosis of patients in oesophagus cancer

Background:

Lin28 is a negative regulator of the tumour suppressor microRNA, let-7, suggesting its role in tumourigenesis. However, the clinical significance of Lin28 expression in oesophageal cancer has not been elucidated.

Methods:

Lin28 and Lin28B expression was examined by immunohistochemistry in 161 tissues from patients with oesophageal cancer who had undergone curative surgery. The relationship between the expressions of Lin28 and Lin28B and various clinicopathological factors was examined. In vitro assays were conducted to determine the role of Lin28 in aggressiveness of oesophageal cancers using oesophageal cancer cell line.

Results:

Lin28 and Lin28B were overexpressed in oesophageal cancer cells compared with non-cancerous epithelial cells, especially in the invasive front. High expression of Lin28 and Lin28B correlated significantly with lymph node metastasis and poor prognosis. High expression of Lin28B expression correlated significantly with low expression of let-7. Multivariate analysis also identified Lin28B expression as an independent prognostic factor. In vitro assays showed that the proliferative and invasive activities were significantly reduced in Lin28B-knockdown cells, compared with control cells.

Conclusion:

High expression of Lin28 is associated with poor prognosis and high tumour aggressiveness in oesophageal cancer and these effects are mediated through increased proliferation and invasiveness of oesophageal cancer cells.     

Overexpression of the RNA-binding proteins Lin28B and IGF2BP3 (IMP3) is associated with chemoresistance and poor disease outcome in ovarian cancer

Background:

RNA-binding proteins have an important role in messenger RNA (mRNA) regulation during tumour development and carcinogenesis. In the present study, we examined the insulin-like growth factor 2 mRNA-binding proteins (IGF2BPs; hereafter refered to as IMPs) and Lin28 family expressions in epithelial ovarian carcinoma (EOC) patients and correlated their expression levels with the response to chemotherapy, hCTR1 expression and patient survival.

Methods:

Patients clinical information, real-time RT-PCR, immunohistochemistry, western blot, Transwell migration invasion assays, and cytotoxicity assays were used.

Results:

From 140 EOC patients, high expression of IMP3 or Lin28B was associated with poor survival, and women diagnosed at advanced stages with elevated IMP3 and Lin28B were at higher risk of developing chemoresistance. High IMP3 levels combined with high Lin28B levels significantly correlated with the poorest 5-year survival rates. Knockdown of IMP3 or Lin28B decreased cell proliferation, migration, and invasion, and increased the platinum sensitivity, but not taxol sensitivity, of ovarian cancer cells through increased expression of hCTR1, a copper transporter involved in platinum uptake. High expression of hCTR1 correlated with low expression of IMP3/Lin28B and better progression-free survival in advanced-stage EOC patients.

Conclusion:

Testing for a combination of elevated IMP3 and Lin28B levels could further facilitate the identification of a patient subgroup with the worst prognosis.     

Linc00673基因在非小细胞肺癌中的表达及临床意义

目的:本研究阐明了非小细胞肺癌（NSCLC）组织及其细胞系内基因长链非编码RNA00673(long intergenic non-coding RNA,LincRNA00673)的表达水平,以及Linc00673 在肺癌中的临床意义及与患者预后的相关性。方法:利用逆转录-聚合酶链反应(qRT-PCR)的实验方法,检测正常肺细胞系与肺癌细胞系之间及肺癌组织与癌旁组织之间Linc00673 的表达水平差异,并分析Linc00673 与肺癌临床病理特征及预后之间的相关性。结果:肺癌细胞系比正常肺细胞系中的Linc00673的表达明显升高,同时肺癌组织比癌旁组织中的Linc00673 明显高表达(P＜0.01);Linc00673的表达与肿瘤的分化程度（P=0.002）、淋巴结转移（P=0.001）、远处转移（P=0.005）和临床分期（P=0.001）相关。并且在吸烟的肺癌患者中Linc00673的表达水平高于非吸烟肺癌患者。肺癌的Linc00673表达水平增高与肺癌患者的预后不良相关（P＜0.01）。结论:Linc00673 的表达与肺癌的发生发展及预后密切相关,有可能成为一个具有特异性的预测性肿瘤分子标志物。     

Lin28: an emerging important oncogene connecting several aspects of cancer

RNA-binding protein Lin28 was originally found as a heterochronic gene which played a significant role in the development of Caenorhabditis elegans. The tumor suppressor let-7 is a downstream target of Lin28, which has a wide variety of target genes which are involved in many aspects of cellular activities. By inhibition of let-7 and directly binding the target RNAs, Lin28 plays an important role in different biological and pathological processes including differentiation, metabolism, proliferation, pluripotency, and tumorigenesis. Overexpression of Lin28 has been reported in several kinds of cancers and is correlated with poor outcomes. It has been shown that Lin28 could affect the progression of cancers in several ways, such as promoting proliferation, increasing glucose metabolism, and inducing epithelial-mesenchymal transition (EMT) and cancer stem cells. Decrease of Lin28 expression or reactivation of let-7 in cancer cells could induce a reverse effect, indicating their therapeutic values in developing novel strategies for cancer treatment. Here, we will overview the regulatory mechanisms and functions of Lin28 in cancers.     

CCL18-mediated down-regulation of miR98 and miR27b promotes breast cancer metastasis

Our previous work has indicated that CCL18 secreted by tumor-associated macrophages (TAMs) promotes breast cancer metastasis, which is associated with poor patient prognosis. However, it remains unclear whether microRNAs (miRNAs), which may modulate multiple cellular pathways, are involved in the regulation of CCL18 signaling and the ensuing metastasis of breast cancer. In this study, we demonstrated that CCL18 reduces miR98 and miR27b expression via the N-Ras/ERK/PI3K/NFκB/Lin28b signaling pathway, while down-regulation of these mRNAs feedbacks to increase N-Ras and Lin28b levels. This cascade of events forms a positive feedback loop that sustains the activation of CCL18 signaling. More importantly, reduction in miR98 and miR27b enhances the epithelial-mesenchymal transition (EMT) of breast cancer cells, and thus promotes breast cancer metastasis. These findings suggest that down-regulation of miR98 and miR27b promotes CCL18-mediated invasion and migration of breast cancer cells.     

Lin28B介导肝癌细胞中HBx相关Let-7沉默

目的:Let-7在多种肿瘤包括肝癌中低表达,扮演抑癌基因角色.我们的前期研究提示HBx(人乙肝病毒X蛋白)在肝癌细胞中显著下调Let-7表达,但内在机制有待进一步揭示.Lin28B能负调控Let-7的转录后加工成熟,这促使我们验证其是否介导了肝癌细胞中HBx相关的Let-7低表达.方法:qRT-PCR检测c-Myc和Lin28B特异siRNA转染HepG2-HBx细胞(HBx稳定转染的HepG2细胞)前后Let-7的表达变化,同时在肝癌细胞和或组织中验证HBx和Lin28B的表达相关性.最后,利用细胞周期及增殖实验检测Lin28B对HepG2细胞的生物学影响.结果:Lin28B高表达于HBx稳定/瞬时转染的HepG2肝癌细胞及HBV阳性的肝癌和肝硬化组织.Lin28B介导了HBx在HepG2肝癌细胞中对Let-7的抑制.Lin28B特异siRNAs可阻滞细胞周期进展进而抑制HepG2细胞生长.结论:HBx 在肝癌细胞中通过诱导Lin28B表达而抑制Let-7.Lin28B可能成为治疗HBV相关肝癌的新靶点.     

Hsa_circ_0003998 Promotes Chemoresistance via Modulation of miR-326 in Lung Adenocarcinoma Cells

Circular RNAs (circRNAs) represent a new class of noncoding RNAs that is involved in the development of cancer. However, little is known about their role in chemoresistance. In the present study, we found that hsa_circ_0003998 expression levels in lung adenocarcinoma (LAD) tissues and docetaxel-resistant cell lines (A549/DTX and H1299/DTX) were upregulated. Knockdown of hsa_circ_0003998 decreased chemoresistance, inhibited proliferation, and enhanced apoptosis in docetaxel-resistant LAD cells. Moreover, by using bioinformatics and luciferase reporter assays, we found that miR-326 was a direct target of hsa_circ_0003998. Functional analysis revealed that miR-326 mediated the effect of hsa_circ_0003998 on chemosensitivity. Our findings provide a molecular insight on understanding drug resistance in LAD cells. Therefore, inactivation of hsa_circ_0003998 or activation of miR-326 could be a novel approach for the treatment of LAD.