KNOCKDOWN OF SURVIVIN EXPRESSION BY SMALL INTERFERING RNA SUPPRESSES PROLIFERATION OF TWO HUMAN CANCER CELL LINES

Objective To construct an expression vector of small interfering RNA （siRNA） against survivin and observe its effects on survivin expression and proliferation of human pancreatic cancer cell line PC-2 and breast cancer cell line MCF-7. Methods Constructed an expression vector of siRNA against survivin and transfected it into PC-2 and MCF-7 cells using lipofectamine^TM 2000. The expression of survivin was detected by semi-quanfifive RT-PCR and immunohistochemistry, and its effects on proliferation of PC-2 and MCF-7 cells were detected by MTT assay. Results The introduction of sequence-specific siRNA could efficiently suppress survivin expression at both mRNA and protein levels in the two cancer cell lines. In PC-2 cells, the expression inhibition rates were 81.25% at mRNA level and 74.24% at protein level In MCF-7 cells, the expression inhibition rates were 64.91% at mRNA level and 79. 72% at protein level The proliferation of PC-2 and MCF-7 cells was also suppressed, and24 and 48 hours after the cells were reseeded, the proliferation inhibition rates of PC-2 cells were 28. 00% and 33. 38%, and that of MCF-7 cells were 31.58% and 33.02%, respectively. Conclusions The expression vector of siRNA against survivin can block survivin expression in PC-2 and MCF-7 cells efficiently and specifically. Down regulation of survivin expression can suppress proliferation of PC-2 and MCF-7 cells. Survivin RNAi may have potential value in gene therapy of human cancers.

The influence of small interfering RNA on the expression of Survivin in human glioma cells

Objective This study aims to investigate the feasibility of knockdown of Survivin gene with small interfering RNA and to observe the apoptosis in gliomas which is influenced by siRNA. Methods Survivin specific siRNA oligonucleotides were designed and synthesized artificially. This siRNA

Small interfering RNA targeting PGC-1α inhibits VEGF expression and tube formation in human retinal vascular endothelial cells

AIMTo determine whether small interfering RNA (siRNA) of PGC-1α could inhibit vascular endothelial growth factor (VEGF) expression and tube formation in human retinal vascular endothelial cells (hRVECs).METHODShRVECs transfected with peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) siRNA were incubated for 24h and then placed into a normoxic (20%, O2) or hypoxic (1%, O2) environment for another 16h. PGC-1α mRNA and protein levels were detected by real-time PCR and Western blot. VEGF mRNA and protein levels were detected by real-time PCR and ELISA. Cell proliferation was evaluated by BrdU incorporation assay. Forty-eight hours after siRNA transfection, hRVECs were planted into Matrigel-coated plates and cultured under normoxic (20%, O2) or hypoxic (1%, O2) conditions for another 48h. The tube formation of hRVECs was observed under an optical microscope and quantified by counting the number of branch points and calculating the total tube length.RESULTSPGC-1α mRNA and protein levels were significantly reduced by PGC-1α siRNA, and VEGF mRNA and protein levels also decreased significantly. The percentage of BrdU-labeled cells in siPGC-1α groups were significantly decreased compared with control siRNA groups under normoxia and hypoxia in cell proliferation assay. In the tube formation assay, PGC-1α siRNA treated cells formed significantly fewer tubes.CONCLUSIONBlocking PGC-1α expression can inhibit VEGF expression in hRVECs and inhibit their ability to form tubes under both normoxic and hypoxic conditions.

Progress of Targeting Transforming Growth Factor-β1 Small Interfering RNA in Liver Fibrosis

Liver fibrosis is a common pathological consequence of a variety of chronic stimuli, including viral, autoimmune, drug-induced, cholestatic and metabolic diseases. Fibrosis is driven by a dynamic process involving increased synthesis of matrix components and a failure of physiological mechanisms of matrix turnover. Activation of hepatic stellate cells(HSCs) remains a central event in fibrosis. HSCs are the main source of extracellular matrix(ECM). Transforming growth factor-beta(TGF-β), which is the fibrogenic master cytokine, can induce the activation of HSCs to produce a large amount of ECM, and is capable of inducing apoptosis of liver cells. RNA interference(RNAi) is a novel gene disruption technology. Studies have shown that small interfering RNA(si RNA) targeting TGF-β1 may inhibit the activation and proliferation of HSCs, suppress ECM synthesis and block liver fibrosis. TGF-β1 si RNA-mediated gene silencing therapy provides a new avenue for liver fibrosis. This review summarizes recent progresses in research on HSCs, TGF-β1 and TGF-β1 si RNA in liver fibrosis.

Impact of Bovine Skeletal Muscle Satellite Cell Differentiation by Small Interfering RNA Targeting Myogenin Gene

To examine the effect of myogenin gene on the differentiation of bovine skeletal muscle satellite cell, we constructed small interfering RNA plasmid vector to obtain myogenin knockdown bovine skeletal muscle cells, then used cell transfection, real time RCR and Western Blot to detect the influence of myogenin to cell differentiation. Results showed that the knockdown of myogenin significantly decreased its expression and other muscle-specific genes. Compared to the control, it could differentiate into few myotubes when challenged by low serum in the medium. These findings provided an important theoretical basis for further explore of the genetic mechanism in adult skeletal muscle, the remedy of muscle injuries and the cultivation of high-yield transgenic cattle.

Small Interfering RNA Targeting TNF-α Gene Significantly Attenuates Renal Ischemia-Reperfusion Injury in Mice

Tumor necrosis factor-alpha（TNF-α） has been found to be centrally involved in the development of ischemia-reperfusion injury（IRI）-induced inflammation and apoptosis. Knockdown of TNF-α gene using small interfering RNA（si RNA） may protect renal IRI. Renal IRI was induced in mice by clamping the left renal pedicle for 25 or 35 min. TNF-α si RNA was administered intravenously to silence the expression of TNF-α. The therapeutic effects of si RNA were evaluated in terms of renal function, histological examination, and overall survival following lethal IRI. A single systemic injection of TNF-α si RNA resulted in significant knockdown of TNF-α expression in ischemia-reperfusion injured kidney. In comparison with control mice, levels of BUN and serum creatinine were significantly reduced in mice treated with si RNA. Pathological examination demonstrated that tissue damage caused by IRI was markedly reduced as a result of TNF-α si RNA treatment. Furthermore, survival experiments showed that nearly 90% of control mice died from lethal IRI, whereas more than 50% of si RNApretreated mice survived until the end of the eight-day observation period. We have demonstrated for the first time that silencing TNF-α by specific si RNA can significantly reduce renal IRI and protect mice against lethal kidney ischemia, highlighting the potential for si RNA-based clinical therapy.

Therapeutic potential of small interfering RNAs/micro interfering RNA in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the predominant form of primary liver cancer and represents the third leading cause of cancer-related death worldwide. Current available therapeutic approaches are poorly effective,especially for the advanced forms of the disease. In the last year,short double stranded RNA molecules termed small interfering RNAs(si RNAs) and micro interfering RNAs(mi RNA),emerged as interesting molecules with potential therapeutic value for HCC. The practical use of these molecules is however limited by the identification of optimal molecular targets and especially by the lack of effective and targeted HCC delivery systems. Here we focus our discussion on the most recent advances in the identification of si RNAs/mi RNAs molecular targets and on the development of suitable si RNA/mi RNAs delivery systems.

Bcl-2 Small Interfering RNA Inhibits the Growth of Human Lymphoma Transplanted Subcutaneously in Nude Mice

OBJECTIVE To investigate whether small hairpin RNA (shRNA)targeting Bcl-2 mRNA could inhibit the growth of lymphomatransplanted subcutaneously in nude mice.METHODS Recombinant Bcl-2 shRNA expression vector withgreen fluorescence protein (GFP) gene was constructed andpreserved in our lab. We evaluated the antitumor effect of the Bcl-2shRNA in vivo which was the model of nude mice bearing Rajicells xenografts. Human Raji cells were injected subcutaneouslyinto nude mice to establish lymphoma models. When thediameters of tumor were above 0.5 cm after Raji cells injection,the mice bearing tumor were randomly divided into four groups:saline control group, negative shRNA group, plasmid vectorgroup, Bcl-2 shRNA group. The polyethylenimine (PEI) was usedto transfect shRNA into tumor. The mixed PEI and shRNA wasinjected into tumors. The growth and size of tumor were observed.Tissue was stained by H&E for its pathological morphology. Theexpression of Bcl-2 mRNA in the tumor mass was detected byreverse transcription polymerase chain reaction (RT-PCR).RESULTS A significant difference in median tumor weightwas observed in mice treated with Bcl-2 shRNA, compared withthose in the groups of negative shRNA or plasmid vector or salinesolution (P< 0.05). Pathological evaluation was completed in allexcised tumors from nude mice bearing Raji cells xenografts.The tumor tissue of the mice treated with Bcl-2 shRNA showedapoptosis, serious necrosis of the cells and inflammatory cellsinfiltration. There was no change in the morphology of cellsamong negative shRNA, plasmid vector and saline solution group.In the group of the Bcl-2 shRNA, the expression levels of Bcl-2mRNA of the tumor tissue were effectively inhibited (P < 0.05).CONCLUSION The shRNA targeting at the Bcl-2 mRNAcould inhibit the growth of human lymphoma transplantedsubcutaneously in nude mice.

Transfer RNA-derived small RNA serves as potential non-invasive diagnostic marker and a novel therapeutic target for acute pancreatitis

Transfer RNA(tRNA)-derived fragments,a new type of tRNA-derived small RNA(tsRNA),can be cleaved from tRNA by enzymes to regulate target gene expression at the transcriptional and translational levels.tsRNAs are not only degradation fragments but also have biological functions,including those in immune inflammation,metabolic disorders,and cell death.tsRNA dysregulation is closely associated with multiple diseases,including various cancers and acute pancreatitis(AP).AP is a common gastrointestinal disease,and its incidence increases annually.AP development is associated with tsRNAs,which regulate cell injury and induce inflammation,especially pyroptosis and ferroptosis.Notably,serum tRF36 has the potential to serve as a non-invasive diagnostic biomarker and leads to pancreatic acinar cell ferroptosis causing inflammation to promote AP.We show the characteristics of tsRNAs and their diagnostic value and function in AP,and discuss the potential opportunities and challenges of using tsRNAs in clinical applications and research.

Combination of small interfering RNAs mediates greater suppression on hepatitis B virus cccDNA in HepG2.2.15 cells

AIM： To observe the inhibition of hepatitis B virus （HBV） replication and expression in HepG2.2.15 cells by combination of small interfering RNAs （siRNAs）. METHODS： Recombinant plasmid psiI-HBV was constructed and transfected into HepG2.2.15 cells. At 48 h, 72 h and 96 h after transfection, culture media were collected and cells were harvested for HBV replication assay. HBsAg and HBeAg in the cell culture medium were detected by enzyme-linked immunoadsorbent assay （ELISA）. Intracellular viral DNA and covalently closed circular DNA （cccDNA） were quantified by real-time polymerase chain reaction （PCR）. HBV viral mRNA was reverse transcribed and quantified by reverse-transcript PCR （RT-PCR）. RESULTS： siRNAs showed marked anti-HBV effects. siRNAs could specifically inhibit the expression of HBsAg and the replication of HBV DNA in a dosedependent manner. Furthermore, combination of siRNAs, compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication. More importantlycombination of siRNAs significantly suppressed HBV cccDNA amplification. CONCLUSION： Combination of siRNAs mediates a stronger inhibition on viral replication and antigenexpression in HepG2.2.15 cells, especially on cccDNA amplification.

Inhibition of genes expression of SARS coronavirus by synthetic small interfering RNAs

RNA interference (RNAi) is triggered by the presence of a double-stranded RNA (dsRNA), and results in the silencing of homologous gene expression through the specific degradation of an mRNA containing the same sequence. dsRNAmediated RNAi can be used in a wide variety of eucaryotes to induce the sequence-specific inhibition of gene expression.Synthetic 21-23 nucleotide (nt) small interfering RNA (siRNA) with 2 nt 3' overhangs was recently found to mediate efficient sequence-specific mRNA degradation in mammalian cells. Here, we studied the effects of synthetic siRNA duplexes targeted to SARS coronavirus structural proteins E, M, and N in a cell culture system. Among total 26 siRNA duplexes, we obtained 3 siRNA duplexes which could sequence-specifically reduce target genes expression over 80％ at the concentration of 60 nM in Vero E6 cells. The downregulation effect was in correlation with the concentrations of the siRNA duplexes in a range of 0～60 nM. Our results also showed that many inactive siRNA duplexes may be brought to life simply by unpairing the 5' end of the antisense strands. Results suggest that siRNA is capable of inhibiting SARS coronavirus genes expression and thus may be a new therapeutic strategy for treatment of SARS.

Effects of Small Interfering RNATargeting Sphingosine Kinase-1 Gene on the Animal Model of Alzheimer's Disease

Summary： Alzheimer＇s disease （AD） is an age-related, progressive neurodegenerative disorder that occurs gradually and results in memory, behavior, and personality changes. Abnormal sphingolipid metabolism was reported in AD previously. This study aimed to investigate whether sphK1 could exacerbate the accumulation of amyloid protein （Aβ） and sharpen the learning and memory ability of the animal model of AD using siRNA interference. An adenovirus vector expressing small interfering RNA （siRNA） against the sphK1 gene （sphKl-siRNA） was designed, and the effects of sphKl-siRNA on the APP/PS1 mouse four weeks after treatment with sphKl-siRNA hippocampal injection were examined. SphK1 protein expression was confirmed by using Western blotting and ceramide content coupled with SIP secretion was evaluated by enzyme-linked immunosorbent assay （ELISA）. Aβ load was detected by immunohistochemical staining and ELISA. Morris water maze was adopted to test the learning and memory ability of the APP/PS 1 mice. A significant difference in the expression of sphK1 protein and mRNA was observed between the siRNA group and the control group. Aβ load in transfected mice was accelerated in vivo, with significant aggravation of the learn- ing and memory ability. The sphKl gene modulation in the All load and the learning and memory ability in the animal model of AD may be important for the treatment of AD.

Molecular mechanisms underlying roles of long non-coding RNA small nucleolar RNA host gene 16 in digestive system cancers

This editorial reviews the molecular mechanisms underlying the roles of the long non-coding RNA(lncRNA)small nucleolar RNA host gene 16(SNHG16)in digestive system cancers based on two recent studies on lncRNAs in digestive system tumors.The first study,by Zhao et al,explored how hBD-1 affects colon cancer,via the lncRNA TCONS_00014506,by inhibiting mTOR and promoting autophagy.The second one,by Li et al,identified the lncRNA prion protein testis specific(PRNT)as a factor in oxaliplatin resistance by sponging ZNF184 to regulate HIPK2 and influence colorectal cancer progression and chemoresistance,suggesting PRNT as a potential therapeutic target for colorectal cancer.Both of these two articles discuss the mechanisms by which lncRNAs contribute to the development and progression of digestive system cancers.As a recent research hotspot,SNHG16 is a typical lncRNA that has been extensively studied for its association with digestive system cancers.The prevailing hypothesis is that SNHG16 participates in the development and progression of digestive system tumors by acting as a competing endogenous RNA,interacting with other proteins,regulating various genes,and affecting downstream target molecules.This review systematically examines the recently reported biological functions,related molecular mechanisms,and potential clinical significance of SNHG16 in various digestive system cancers,and explores the relationship between SNHG16 and digestive system cancers.The findings suggest that SNHG16 may serve as a potential biomarker and therapeutic target for human digestive system cancers.

Inhibition of HOXB7 Gene Expression in Melanoma Cells by Small Interfering RNA

Objective： HOXB7 gene is a kind of transcription regulator over-expressed in malignant melanoma （MM） cell lines. It can specifically up-regulate the expression of angiogenic factors and tumor growth factors such as bFGF, GROa, VEGF and induce angiogenesis in melanoma, resulting in the proliferation and metastasis of tumor cells. We designed and synthesized HOXB7 specific siRNA to study its interfering effect on the expressions of HOXB7 and bFGF genes in melanoma A375 cell line and the biologic characteristics of A375 cells. Methods： Three synthesized siRNA with different sequences were separately transfected into A375 cells by lipofecter 2000. The expression of HOXB7 and bFGF mRNA in transfected cells was detected by RT-PCR 24 and 48 hours after transduction. The expression of bFGF protein in the transfected cells were detected by flowcytometry 48 hours after transfection. MTT assay was used to analyze the cell proliferation rate of siRNA transfected cells. Based on the in vitro experiment results, one effective siRNA sequence was selected for the construction of in vivo siRNA expression vector. Then, a malignant melanoma animal model was established. The siRNA expression plasmid was injected into the tumor foci and its influence on the growth and angiogenesis of tumor was observed. Results： The mRNA expressions of both HOXB7 and bFGF genes in the A375 cells reduced significantly 24 and 48 hour after transfection of siRNA. Expression level of the protein of angiogenic factor bFGF induced by HOXB7 gene in siRNA transfected cells was significantly lower than that in control cells 48 hours after transduction. Cell proliferation was also suppressed in siRNA transfected cells. Two of the three siRNA strands showed prominent interference effect. The in vivo study indicated that the tumor size and the microvessel density in the tumor both reduced after injection of HOXB7siRNA plasmid. Conclusion： Down-regulation of HOXB7 gene expression can effectively reduce the expression of angiogenic factor bFGF and the proliferation of MM cells. Besides, the growth and angiogenesis of MM tumor were also inhibited.

lncRNA SNHG4 enhanced gastric cancer progression by modulating miR-409-3p/CREB1 axis

Objective:Gastric cancer(GC)is a globally common cancer characterized by high incidence and mortality worldwide.Advances in the molecular understanding of GC provide promising targets for GC diagnosis and therapy.Long non-coding RNAs(lncRNAs)and their downstream regulators are regarded to be implicated in the progression of multiple types of malignancies.Studies have shown that the lncRNA small nucleolar RNA host gene 4(SNHG4)serves as a tumor promoter in various malignancies,while its function in GC has yet to be characterized.Therefore,our study aimed to explore the role and underlying mechanism of SNHG4 in GC.Methods:We used qRT-PCR to analyze SNHG4 expression in GC tissues and cells.Kaplan-Meier analysis was used to assess the correlation between SNHG4 expression and the survival rate of GC patients.Cellular function experiments such as CCK-8,BrdU,colony formation,flow cytometry analysis,and transwell were performed to explore the effects of SNHG4 on GC cell proliferation,apoptosis,cell cycle,migration,and invasion.We also established xenograft mouse models to explore the effect of SNHG4 on GC tumor growth.Mechanically,dual luciferase reporter assay was used to verify the interaction between SNHG4 and miR-409-3p and between miR-409-3p and cAMP responsive element binding protein 1(CREB1).Results:The results indicated that SNHG4 was overexpressed in GC tissues and cell lines,and was linked with poor survival rate of GC patients.SNHG4 promoted GC cell proliferation,migration,and invasion while inhibiting cell apoptosis and cell cycle arrest in vitro.The in vivo experiment indicated that SNHG4 facilitated GC tumor growth.Furthermore,SNHG4 was demonstrated to bind to miR-409-3p.Moreover,CREB1 was directly targeted by miR-409-3p.Rescue assays demonstrated that miR-409-3p deficiency reversed the suppressive impact of SNHG4 knockdown on GC cell malignancy.Additionally,miR-409-3p was also revealed to inhibit GC cell proliferation,migration,and invasion by targeting CREB1.Conclusion:In conclusion,we verified that the SNHG4 promoted GC growth and metastasis by binding to miR-409-3p to upregulate CREB1,which may deepen the understanding of the underlying mechanism in GC development.

Small nucleolar RNA and its potential role in the oncogenesis and development of colorectal cancer

Small nucleolar RNAs(snoRNAs)represent a class of non-coding RNAs that play pivotal roles in post-transcriptional RNA processing and modification,thereby contributing significantly to the maintenance of cellular functions related to protein synthesis.SnoRNAs have been discovered to possess the ability to influence cell fate and alter disease progression,holding immense potential in controlling human diseases.It is suggested that the dysregulation of snoRNAs in cancer exhibits differential expression across various cancer types,stages,metastasis,treatment response and/or prognosis in patients.On the other hand,colorectal cancer(CRC),a prevalent malignancy of the digestive system,is characterized by high incidence and mortality rates,ranking as the third most common cancer type.Recent research indicates that snoRNA dysregulation is associated with CRC,as snoRNA expression significantly differs between normal and cancerous conditions.Consequently,assessing snoRNA expression level and function holds promise for the prognosis and diagnosis of CRC.Nevertheless,current comprehension of the potential roles of snoRNAs in CRC remains limited.This review offers a comprehensive survey of the aberrant regulation of snoRNAs in CRC,providing valuable insights into the discovery of novel biomarkers,therapeutic targets,and potential tools for the diagnosis and treatment of CRC and furnishing critical cues for advancing research into CRC and the judicious selection of therapeutic targets.

Nanoparticles for targeted delivery of therapeutics and small interfering RNAs in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is the 5th most common malignancy which is responsible for more than half million annual mortalities; also, it is the third leading cause of cancer related death. Unfavorablesystemic side-effects of chemotherapeutic agents and susceptibility to the degradation of small interfering RNAs(si RNAs), which can knock down a specific gene involved in the disease, have hampered their clinical application. So, it could be beneficial to develop an efficient carrier for the stabilization and specific delivery of drugs and si RNA to cells. Targeted nanoparticles have gained considerable attention as an efficient drug and gene delivery system, which is due to their capability in achieving the highest accumulation of cytotoxic agents in tumor tissue, modifiable drug pharmacokinetic- and bio-distribution, improved effectiveness of treatment, and limited sideeffects. Recent studies have shed more light on the advantages of novel drug loaded carrier systems vs free drugs. Most of the animal studies have reported improvement in treatment efficacy and survival rate using novel carrier systems. Targeted delivery may be achieved passively or actively. In passive targeting, no ligand as homing device is used, while targeting is achieved by incorporating the therapeutic agent into a macromolecule or nanoparticle that passively reaches the target organ. However, in active targeting, the therapeutic agent or carrier system is conjugated to a tissue or cell-specific receptor which is overexpressed in a special malignancy using a ligand called a homing device. This review covers a broad spectrum of targeted nanoparticles as therapeutic and nonviral si RNA delivery systems, which are developed for enhanced cellular uptake and targeted gene silencing in vitro and in vivo and their characteristics and opportunities for the clinical applications of drugs and therapeutic si RNA are discussed in this article. Asialoglycoprotein receptors, low-density lipoprotein, ganglioside GM1 cell surface ligand, epidermal growth factor receptor receptors, monoclonal antibodies, retinoic acid receptors, integrin receptors targeted by Arg-Gly-Asp peptide, folate, and transferrin receptors are the most widely studied cell surface receptors which are used for the site specific delivery of drugs and si RNA-based therapeutics in HCC and discussed in detail in this article.

Genetic diversity of the S-type small subunit ribosomal RNA gene of Plasmodium knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia

Objective:To determine the genetic diversity of Plasmodium(P.)knowlesi isolates from Sabah,Malaysian Borneo and Peninsular Malaysia,targeting the S-type SSU rRNA gene and including aspects of natural selection and haplotype.Methods:Thirty-nine blood samples infected with P.knowlesi were collected in Sabah,Malaysian Borneo and Peninsular Malaysia.The S-type SSU rRNA gene was amplified using polymerase chain reaction,cloned into a vector,and sequenced.The natural selection and haplotype of the S-type SSU rRNA gene sequences were determined using DnaSP v6 and illustrated using NETWORK v10.This study's 39 S-type SSU rRNA sequences and eight sequences from the Genbank database were subjected to phylogenetic analysis using MEGA 11.Results:Overall,the phylogenetic analysis showed no evidence of a geographical cluster of P.knowlesi isolates from different areas in Malaysia based on the S-type SSU rRNA gene sequences.The S-type SSU rRNA gene sequences were relatively conserved and with a purifying effect.Haplotype sharing of the S-type SSU rRNA gene was observed between the P.knowlesi isolates in Sabah,Malaysian Borneo,but not between Sabah,Malaysian Borneo and Peninsular Malaysia.Conclusions:This study suggests that the S-type SSU rRNA gene of P.knowlesi isolates in Sabah,Malaysian Borneo,and Peninsular Malaysia has fewer polymorphic sites,representing the conservation of the gene.These features make the S-type SSU rRNA gene suitable for comparative studies,such as determining the evolutionary relationships and common ancestry among P.knowlesi species.

Silencing invariant chain of DCs enhances Th1 response using small interfering RNA

RNA interference(RNAi),which causes the degradation of any RNA in a sequence specific manner,is a posttranscriptional gene silencing mechanism.Targeting the invariant chain(Ii)in DCs has been used as an approach to enhance antitumor immunity.It is demonstrated in this article that transfection of H-2(K)DCs with siRNA specific for Ii gene can significantly knock down Ii.When exposed to TNF-alpha,immature DCs transfected with Ii siRNA can differentiate into mature DCs without reducing viability or IL-12p70 production.Ii siRNA-treated H-2(K)DCs exhibited an increased allostimulatory capacity in a lymphocyte proliferation assay.Furthermore,Ii siRNA-transfected H-2(K)DCs enhanced Th1 responses by increasing IFN-gamma and decreasing IL-4 production,and much stronger cytotoxic activity was observed when DCs were co-transfected with Ii siRNA and an endogenous tumor antigen in vitro.Our findings indicate that silencing the Ii gene in DCs with siRNA may offer a potential approach to enhancing antitumor immunotherapy.

LncRNA SNHG20靶向调控miR-520c-3p/RAB22A通路对人口腔鳞状细胞癌细胞上皮间质转化及微管形成的影响

目的:探究LncRNA SNHG20靶向调控miR-520c-3p/RAB22A通路对人口腔鳞状细胞癌(oral squamous cell carcinoma,OSCC)细胞上皮间质转化(epithelial-mesenchymal transition,EMT)及微管形成的影响。方法:检测OSCC细胞及组织中LncRNA SNHG20、miR-520c-3p、RAB22A mRNA水平及其相互间关系。将OSCC细胞分为对照组、sh-NC组、sh-SNHG20组、sh-SNHG20+anti-NC组、sh-SNHG20+anti-miR-520c-3p组,检测OSCC细胞EMT蛋白表达,检测微管形成数量变化,裸鼠成瘤实验检测LncRNA SNHG20对OSCC肿瘤生长的影响。结果:OSCC组织和细胞中LncRNA SNHG20、RAB22A mRNA上调表达,miR-520c-3p下调表达(P<0.05);LncRNA SNHG20与miR-520c-3p、RAB22A与miR-520c-3p之间均有结合位点;与sh-NC组相比,sh-SNHG20组间质样细胞数量较少,上皮样细胞数量较多,微管结构不完整且结节数量较少,LncRNA SNHG20、RAB22A、N-cadherin、vimentin下调表达,miR-520c-3p、E-cadherin上调表达(P<0.05);与sh-SNHG20+anti-NC组相比,sh-SNHG20+anti-miR-520c-3p组间质样细胞数量较多,上皮样细胞数量较少,微管排列较紧密,微管结节数量较多,miR-520c-3p、E-cadherin下调表达,RAB22A、N-cadherin、vimentin上调表达(P<0.05)。sh-SNHG20组比sh-NC组OSCC移植瘤体积较小,质量较低,LncRNA SNHG20、RAB22A下调表达,miR-520c-3p上调表达(P<0.05)。结论:抑制LncRNA SNHG20表达能够靶向调节miR-520c-3p/RAB22A通路抑制OSCC细胞EMT和微管形成。