Pancreatic ductal adenocarcinoma cells regulated the gemcitabine‐resistance function of CAFs by LINC00460

Pancreatic ductal adenocarcinoma (PDAC) is a highly fatal malignancy with extremely poor prognosis. Gemcitabine resistance is a major challenge in the treatment of PDAC. Here, we showed that LINC00460 was associated with the response to gemcitabine both in PDAC patients and PDAC‐PDX. After knocking down LINC00460 in PDAC tumor cells, results of RNA sequencing followed by gene ontology analysis indicated that LINC00460 influenced the activity of growth factors and modified the extracellular matrix. FISH showed that LINC00460 is mostly located in the cytoplasm. Results of RNA pull‐down, LC–MS/MS, RIP, and immunoblotting confirmed that LINC00460 could directly bind to PDAP1. Furthermore, we demonstrated that LINC00460 mediated the cellular communication of PDAC tumor cells and CAFs by PDAP1/PDGFA/PDGFR signaling pathway and regulated the gemcitabine‐resistance function of CAFs, which could be reversed by treatment with a PDGFR inhibitor (crenolanib). PDAC‐PDX tumors with lower expression of LINC00460 showed a better response to gemcitabine plus crenolanib treatment. Our finding supported the application of LINC00460 in precision medicine that uses gemcitabine plus crenolanib to treat PDAC with low expression of LINC00460.     

LINC00511靶向miR-497-5p调控胃癌细胞增殖、迁移和侵袭及机制研究

目的:探讨LINC00511对胃癌细胞增殖、迁移和侵袭的影响及其作用机制。方法:将pcDNA、pcDNA-LINC00511、si-NC、si-LINC00511、miR-NC、miR-497-5p分别转染至MGC-803细胞中,分别记为pcDNA组、pcDNA-LINC00511组、si-NC组、si-LINC00511组、miR-NC组、miR-497-5p组;将si-LINC00511质粒分别与anti-miR-NC、anti-miR-497-5p共转染至MGC-803细胞中,分别记为si-LINC00511+anti-miR-NC组、si-LINC00511+anti-miR-497-5p组。实时荧光定量PCR（RT-qPCR）检测miR-497-5p和LINC00511表达水平;蛋白质印迹（Western Blot）法检测细胞周期素D1（cyclin D1,CyclinD1）、p21、基质金属蛋白酶2（matrix metalloproteinase 2,MMP2）、基质金属蛋白酶9（matrix metalloproteinase 9,MMP9）蛋白表达水平;四甲基偶氮唑盐比色法(MTT)检测细胞活性;Transwell检测细胞迁移和侵袭;双荧光素酶报告基因实验检测LINC00511和miR-497-5p的靶向关系。结果:与正常胃黏膜上皮细胞GES-1相比,胃癌细胞MGC-803、MKN-45、AGS中miR-497-5p表达水平显著降低,LINC00511表达水平显著升高。LINC00511靶向调控miR-497-5p的表达。抑制LINC00511表达和miR-497-5p过表达可降低细胞活性和迁移、侵袭数量,降低CyclinD1、MMP2、MMP9蛋白表达水平,提高p21蛋白表达水平。干扰miR-497-5p表达逆转了抑制LINC00511表达对胃癌MGC-803细胞增殖、迁移和侵袭的抑制作用。结论:抑制LINC00511表达可抑制胃癌细胞增殖、迁移和侵袭,其机制可能与miR-497-5p表达有关,将为胃癌的治疗提供新思路和新靶点。     

Long noncoding RNA LINC01234 promotes hepatocellular carcinoma progression through orchestrating aspartate metabolic reprogramming

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LncRNA LINC00115 facilitates lung cancer progression through miR-607/ITGB1 pathway

Dysregulated long noncoding RNAs (lncRNAs) have potential roles in various cancer types. The objective of this study was to investigate the expression and the underlying role of long intergenic nonprotein coding RNA 115 (LINC00115) in lung cancer. The relative expression of LINC00115 and miR-607 in tumor tissues and cells was detected by real-time PCR. After overexpression or knockdown of LINC00115 expression in tumor cells, the changes in the proliferation, migration, and invasion capacities were detected via Counting Kit-8 (CCK-8) assay and transwell assays. The interplay among LINC00115, miR-607, and integrin β1 (ITGB1) was confirmed by bioinformatics analyses and luciferase reporter assay. In addition, tumor cells with LINC00115 knockdown were injected into nude mice to investigate the effect of LINC00115 on tumorigenesis in vivo. LINC00115 was highly expressed in tumor tissues and cells. LINC00115 promoted the malignant properties of tumor cells. Investigation to its molecular mechanism revealed that LINC00115 functioned as a competitive endogenous RNA (ceRNA), regulating the expression of ITGB1 by sponging miR-607 to affect tumor growth. The LINC00115/miR-607/ITGB1 signaling axis might be a novel therapeutic target in lung cancer.     

Decreased mechanotransduction prevents nuclear collapse in a Caenorhabditis elegans laminopathy

The function of the nucleus depends on the integrity of the nuclear lamina, an intermediate filament network associated with the linker of nucleoskeleton and cytoskeleton (LINC) complex. The LINC complex spans the nuclear envelope and mediates nuclear mechanotransduction, the process by which mechanical signals and forces are transmitted across the nuclear envelope. In turn, the AAA+ ATPase torsinA is thought to regulate force transmission from the cytoskeleton to the nucleus. In humans, mutations affecting nuclear envelope-associated proteins cause laminopathies, including progeria, myopathy, and dystonia, though the extent to which endogenous mechanical stresses contribute to these pathologies is unclear. Here, we use the Caenorhabditis elegans germline as a model to investigate mechanisms that maintain nuclear integrity as germ cell nuclei progress through meiotic development and migrate for gametogenesis—processes that require LINC complex function. We report that decreasing the function of the C. elegans torsinA homolog, OOC-5, rescues the sterility and premature aging caused by a null mutation in the single worm lamin homolog. We show that decreasing OOC-5/torsinA activity prevents nuclear collapse in lamin mutants by disrupting the function of the LINC complex. At a mechanistic level, OOC-5/torsinA promotes the assembly or maintenance of the lamin-associated LINC complex and this activity is also important for interphase nuclear pore complex insertion into growing germline nuclei. These results demonstrate that LINC complex-transmitted forces damage nuclei with a compromised nuclear lamina. Thus, the torsinA–LINC complex nexus might comprise a therapeutic target for certain laminopathies by preventing damage from endogenous cellular forces.

Nuclear mechanotransduction enables the nucleus to adapt its rigidity in response to applied forces and is necessary for transmitting mechanical signals across the nuclear envelope (NE) and for maintaining the integrity of the genome (1, 2). Nuclear mechanotransduction requires an intact nuclear lamina, which comprises an intermediate filament network of lamins and associated proteins that line the nuclear-facing surface of the NE. The LINC (linker of nucleoskeleton and cytoskeleton) complex is a core NE component required for nuclear mechanotransduction, as it acts as a molecular bridge coupling the inside of the nucleus with the cytoplasm. The LINC complex consists of two interacting protein components: 1) SUN (Sad1 and UNC-84) domain proteins in the inner nuclear membrane; and 2) KASH (Klarsicht, ANC-1, Syne homology) domain proteins in the outer nuclear membrane (2). The LINC complex is tethered to the cytoplasmic cytoskeleton and nuclear lamins and transduces forces across the NE.Mutations in many NE components are associated with a range of seemingly unrelated tissue-specific pathologies, collectively known as nuclear envelopathies (3). The apparent tissue specificity of these diseases is somewhat surprising because most of these NE components are widely expressed proteins. For example, mutations in genes encoding nuclear lamins cause diseases, including Hutchinson-Gilford progeria, dyslipidemias, and myopathies (3). By contrast, mutations affecting the NE-associated AAA+ ATPase (ATPases associated with diverse cellular activities) torsinA cause early-onset DYT1 dystonia and congenital joint contractures (4–6). An attractive hypothesis is that endogenous mechanical forces contribute to the pathology of nuclear envelopathies by causing damage to cells with defective NE components, yet few studies have directly tested this possibility. In many cases, experimental investigations are hampered by the fact that the mechanistic functions of many key NE components remain incompletely understood—such is the case of torsinA.In this study, we set out to elucidate molecular interactions and mechanisms by which torsinA functions in the NE. Although the cellular functions of torsinA have remained enigmatic, they appear to be conserved across cell types and species because distantly related organisms lacking torsinA function display similar ultrastructural NE defects (7, 8). A plausible hypothesis is that torsinA plays a role in regulating nuclear mechanotransduction, as its loss disrupts cell migration, nuclear positioning, and polarization (8–10). Yet, torsinA has been implicated in other cellular processes, including endoplasmic reticulum (ER) stress (11–14), lipid metabolism (15), and membrane remodeling (16). In this study, we took advantage of the fact that mutations in the Caenorhabditis elegans torsinA ortholog, OOC-5 (abnormal oocyte formation, 5), cause oocyte growth and embryonic polarity defects (17, 18). Further, we used the C. elegans germline as a model system to investigate how cytoskeletal forces are transduced as germ cell nuclei progress through meiosis and migrate for gametogenesis. Our results reveal that OOC-5/torsinA promotes the activity of the LINC complex in transducing forces to the nuclear lamina. Remarkably, decreasing the function of OOC-5/torsinA or the LINC complex prevents nuclear collapse in the absence of a functional nuclear lamina. These results highlight a critical role for torsinA in nuclear mechanotransduction and suggest that an inability to cope with endogenous and exogenous forces may underlie the etiology of nuclear envelopathies.     

Integrative Analysis of NSCLC Identifies LINC01234 as an Oncogenic lncRNA that Interacts with HNRNPA2B1 and Regulates miR-106b Biogenesis

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LINC00659靶向miR-149-5p调控食管鳞癌细胞Eca-109的增殖、迁移、侵袭及放射敏感性

目的 探讨长基因间非编码RNA 00659(LINC00659)是否靶向miR-149-5p调控食管鳞癌Eca-109细胞的增殖、 迁移侵袭及放射敏感性.方法 实时定量PCR(RT-qPCR)分析30对食管鳞癌组织、 对照组织中LINC00659和miR-149-5p表达量.将Eca-109细胞分为si-NC组、si-...