ARN de interferencia (ARNi): una herramienta eficaz en agrobiotecnología / RNA interference (RNAi): an effective tool in agrobiotechnology

RESUMEN El ARN de interferencia (ARNi) es un mecanismo evolutivamente conservado en la mayoría de las células eucariotas que permite silenciar genes mediante la degradación de ARN mensajero (ARNm) y la supresión de la síntesis de proteínas. En plantas, las moléculas de ARNi están involucradas en mecanismos de defensa contra patógenos y transposones, en la respuesta adaptativa al estrés, y en la expresión de genes relacionados con su crecimiento. El ARNi se considera una herramienta biotecnológica eficaz para silenciar la expresión de genes de microorganismos fitopatógenos, esto permite el diseño de bioplaguicidas ambientalmente seguros con una afinidad y selectividad, en muchos casos superior a la de los plaguicidas químicos. En esta revisión se señalan los últimos avances en la aplicación del ARNi en el contexto agrícola y su efectividad en el control biológico de fitopatógenos e insectos plaga. Asimismo, se presentan diversos ensayos experimentales cuyos resultados pueden ser la base para futuros bioproductos, además de algunos ejemplos disponibles en el mercado. Por último, se abordan aspectos de bioseguridad y consideraciones regulatorias necesarias para la aceptación y uso de esta tecnología a nivel global.

ABSTRACT RNA interference (RNAi) is an evolutionarily conserved mechanism in most eukaryotic cells that allows genes to be silenced by degradation of messenger RNA (mRNA) and suppression of protein synthesis. In plants, RNAi molecules are involved in defense mechanisms against pathogens and transposons, in the adaptive response to stress, and in the expression of genes related to their growth. RNAi is an effective biotechnological tool to silence the expression of specific genes which are essential for the survival of phytopathogenic microorganisms, thus allowing the design of environmentally safe biopesticides with affinity and selectivity, in many cases greater than chemical pesticides. This review describes the latest advances in the application of RNAi in the agricultural context and its effectiveness in the biological control of phytopathogens and pest insects. Likewise, various experimental trials are presented, the results of which may be the basis for future bioproducts, as well as some examples available on the market. Finally, biosafety aspects and regulatory considerations necessary for the acceptance and use of this technology at a global level are presented.

Effect of β-catenin RNAi Interference on Signal Mechanism of Huangjingwan in Treating Learning and Memory Impairment Mice / 中国实验方剂学杂志

Objective:To treat mice with Alzheimer's disease （AD） with β-catenin RNA interference （RNAi） Huangjingwan （HW）， so as to explore the neuroprotective signal mechanism of its prevention and treatment of AD. Method:A total of 81 male Kunming mice were randomly divided into normal control group， sham model control group， AD model group， Donepezil group， HW+scrambled group， HW+RNAi group， HW group， with 8 mice in each of donepezil group and HW group， and 13 mice in each of other groups. The AD models were established through injection with D-galactose and scopolamine in the last 5 groups for 5 consecutive weeks. On the 1st day of the 4th week after modeling， 0.75 μL PEI-LMW/β-catenin siRNAs nano-complex was injected into the right lateral ventricle of each mouse in for one time to treat with β-catenin RNAi in mice brains of the HW+RNAi group. The 0.75 μL complex was injected into the right lateral ventricle of each mouse for one time as for β-catenin interference control of the HW+scrambled group. The 0.75 μL normal saline was injected into the right lateral ventricle of each mouse in one time of the sham control group. Two weeks after intracerebroventricular injection， β-catenin RNAi was confirmed to be successful， and Donepezil （6.5×10-4 g·kg-1） was intragastrically administered to each mouse of donepezil group. HW （2.5 g·kg-1） was intragastrically administered to each mouse of HW group， HW+RNAi group and HW+scrambled group. Normal saline （0.5 mL·d-1） was intragastrically administered to each mouse of the sham control group. All gastric perfusion lasted for 4 weeks. At the end of gavage， the difference in learning and memory ability of mice was evaluated by platform jumping test. Nissl staining was used to count the number of neurons in s1Tr area of cerebral cortex and CA1 and CA3 areas of hippocampus of each mouse in each group. The mRNA expressions of Wnt1， DVL2， GSK-3β， β-catenin and CyclinD1 in mice brain of each group were detected by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）. Western blot was used to detect the expressions of Wnt1， DVL2， GSK-3β， β-catenin and CyclinD1 in mice brain of each group. Result:The expression of β-catenin could be significantly inhibited through the injection with PEI-LMW/β-catenin siRNAs nano-complex into the lateral ventricle of AD mice， and nearly no β-catenin expression could be detected， which successfully achieved gene silencing. Compared with the normal control group， mice in AD model group showed that the learning and memory performance decreased significantly， the number of jumping errors increased （P<0.01）， the number of neurons in S1Tr area of cerebral cortex and CA1， CA3 areas of hippocampus decreased significantly （P<0.01）， the mRNA and protein expressions of Wnt1， DVL2， β-catenin， CyclinD1 in brain decreased significantly （P<0.01）， while the mRNA and protein expressions of GSK-3β increased significantly （P<0.01）. Compared with the AD model group， mice in HW group showed that the learning and memory performance increased significantly， the number of jumping errors decreased， the number of neurons in S1Tr area of cerebral cortex and CA1， CA3 areas of hippocampus increased significantly， the mRNA and protein expressions of Wnt1， DVL2， β-catenin， CyclinD1 in brain increased significantly， while the mRNA and protein expression of GSK-3β decreased significantly （P<0.01）. Compared with the HW group， mice in HW+RNAi group showed that the learning and memory performance decreased significantly， the number of jumping errors increased significantly （P<0.01）， the number of neurons in S1Tr area of cerebral cortex and CA1， CA3 areas of hippocampus decreased significantly （P<0.01）， there was no significant change in mRNA and protein expressions of Wnt1， DVL2， GSK-3β in the brain， and the mRNA and protein expressions of β-catenin， CyclinD1 decreased significantly （P<0.01）. Conclusion:HW can treat and prevent AD by activating Wnt/β-catenin signal pathway.

Post-transcriptional gene silencing: Basic concepts and applications

Post-transcriptional gene silencing (PTGS)-mediated gene silencing exploits the cellular mechanism whereintranscripts having sequence similarity to the double-stranded RNA (dsRNA) molecules present in the cell will besubjected to degradation. PTGS is closely related to natural processes such as RNA-mediated virus resistance andcross-protection in plants. Gene silencing and the cellular machinery for affecting this phenomenon might haveevolved as a natural protective measure against viral infection in plants. In PTGS, small interfering RNA (siRNA)molecules of 21–23 nucleotides length act as homology guides for triggering the systemic degradation of transcriptshomologous to the siRNA molecules. PTGS phenomenon, first discovered in transgenic petunia plants harbouringchalcone synthase gene and termed co-suppression, has been subsequently exploited to target specific gene transcripts for degradation leading to manifestation of desirable traits in crop plants. Targeted gene silencing has beenachieved either through the introduction of DNA constructs encoding dsRNA or antisense RNA or by deploying cosuppression constructs producing siRNAs against the transcript of interest. Understanding the mechanism of genesilencing has led to the development of several alternative strategies for inducing gene silencing in a precise andcontrolled way. This has paved the way for using PTGS as one ofthe chief functional genomicstools in plants and hashelped in unraveling the mechanism of many cellular processes and identifying the focal points in pathways, besides,opening new vistas in genetic engineering of plants for human benefits. PTGS has shown great potential in silencingthe deleterious genes efficiently so that value-added plant products could be obtained. Thus, PTGS has ushered in anew era in the genetic manipulation of plants for both applied and basic studies. In this review, we have outlined thebasics of RNAi-mediated gene silencing and summarized the work carried out at our institute using this approach, ascase studies. In particular, adopting RNAi-mediated gene silencing (a) as a method to restore fertility in transgenicmale sterile lines developed based on orfH522 gene from sunflower PET1-CMS source, (b) as a tool to suppress theproduction of toxic proteins, ricin and RCA, in castor, and (c) as an approach to induce bud necrosis virus resistancein sunflower has been discussed. Examples from other plant systems also have been mentioned to exemplify theconcept and utility of gene silencing in crop plants.

RNAi suppressor: The hidden weapon of SARS-CoV

The two biological evidences to endorse the antiviral activity of RNA interference (RNAi) are biogenesis ofviral-siRNA (v-siRNA) by the host and encoding of RNAi-suppressor protein by viral genome. It has beenrecently established that mammals and mammalian cell lines mount antiviral RNAi to defend themselvesagainst the invading viruses. The large part of viral pathogenicity is also due to the RNAi suppressor proteins.In this context it is only natural to ask what kinds of RNAi suppressors are encoded by the Severe AcuteRespiratory Syndrome Coronavirus 2 (SARS-CoV-2), the central character of the present pandemic. Thefollowing mini review addresses this question.

Function and Characterization of the Argonaute2 Gene in the RNA Interference Pathway in the Diamondback Moth

Arch BiochemMol Biol2019;10(4):035-051DOI: 10.26502/abmb.007Archives of Biochemistry and Molecular BiologyVol. 10 No. 4 -December2019. 36AbstractArgonaute2 (AGO2) is a core catalytic component of the RNA-induces silencing complex (RISC) that binds to small guide RNAs containing small interfering RNA (siRNA) and microRNA (miRNA). The guide RNA leads RISC to the complementary mRNA for gene suppression. We cloned the full length cDNA (2193 bp) of the Ago2gene (PxAgo2) from diamondback moth (DBM, Plutella xylostella). The predicted PxAgo2 protein hadan83 kDa molecular weight withatheoretical isoelectric point of 9.39. The phylogenetic tree showed a high similarity of PxAgo2with Bombyx moriAgo2 (BmAgo2). Western blot and RT-qPCR analyses showed a clear increase in the PxAgo2 mRNA and protein expression levels in the egg, 4thinstar larva, pre-pupa, pupa and adult. The double-stranded RNA-mediated RNAi of PxAgo2in DBM larvae was found 3 h after dsRNA injection,and the knockdown level was increased over time up to 36 h. PxAgo2silencing recovered the expression of PxBurs-?(Bursicon-? inDBM) to the normal expression level, which was suppressed bydsPxBurs-?in a DBM cell line. The overexpression of PxAgo2fundamentally enhanced the PxBurs-? silencing efficiency in DBM cells. Our findings reveal that PxAgo2is involved in the dsRNA-regulated gene silencing mechanism and performs a crucial function in the RNAi process ofDBM

Biological roles of filamin a in prostate cancer cells

ABSTRACT Objective This study aims to investigate the association of filamin A with the function and morphology of prostate cancer (PCa) cells, and explore the role of filamin A in the development of PCa, in order to analyze its significance in the evolvement of PCa. Materials and Methods A stably transfected cell line, in which filamin A expression was suppressed by RNA interference, was first established. Then, the effects of the suppression of filamin A gene expression on the biological characteristics of human PCa LNCaP cells were observed through cell morphology, in vitro cell growth curve, soft agar cloning assay, and scratch test. Results A cell line model with a low expression of filamin A was successfully constructed on the basis of LNCaP cells. The morphology of cells transfected with plasmid pSilencer-filamin A was the following: Cells were loosely arranged, had less connection with each other, had fewer tentacles, and presented a fibrous look. The growth rate of LNCap cells was faster than cells transfected with plasmid pSilencer-filamin A (P <0.05). The clones of LNCap cells in the soft agar cloning assay was significantly fewer than that of cells stably transfected with plasmid pSilencer-filamin A (P <0.05). Cells stably transfected with plasmid pSilencer-filamin A presented with a stronger healing and migration ability compared to LNCap cells (healing rate was 32.2% and 12.1%, respectively; P <0.05). Conclusion The expression of the filamin A gene inhibited the malignant development of LNCap cells. Therefore, the filamin A gene may be a tumor suppressor gene.

Delivery of BACE1 siRNA mediated by TARBP-BTP fusion protein reduces b-amyloid deposits in a transgenic mouse model of Alzheimer’s disease

Systemic delivery of nucleic acids to the central nervous system (CNS) is a major challenge for the development of RNAinterference-based therapeutics due to lack of stability, target specificity, non-permeability to the blood–brain barrier (BBB),and lack of suitable carriers. Using a designed bi-functional fusion protein TARBP-BTP in a complex with siRNA, weearlier demonstrated knockdown of target genes in the brain of both AbPP-PS1 (Alzheimer’s disease, AD) and wild-typeC57BL/6 mice. In this report, we further substantiate the approach through an extended use in AbPP-PS1 mice, which upontreatment with seven doses of b-secretase AbPP cleaving Enzyme 1 (BACE1) TARBP-BTP:siRNA, led to target-specificeffect in the mouse brain. Concomitant gene silencing of BACE1, and consequent reduction in plaque load in the cerebralcortex and hippocampus ([60%) in mice treated with TARBP-BTP:siRNA complex, led to improvement in spatial learningand memory. The study validates the efficiency of TARBP-BTP fusion protein as an efficient mediator of RNAi, givingconsiderable scope for future intervention in neurodegenerative disorders through the use of short nucleic acids as genespecific inhibitors.

Effects of B7-2 gene RNAi lentiviral vector on dendritic cells and T lymphocytes proliferation induced by dendritic cells in vitro / 中国免疫学杂志

Objective: To generate mouse B7-2 gene RNAi lentivirus and study its interference effects on B7-2 expression and T lymphocytes proliferation induced by dendritic cells. Methods: Three sequences specific targeting B7-2 gene and one non-specific sequence were respectively synthesized, and inserted into lentiviral vector, then the recombinant vectors were sequencing. 293 T cells were co-transfected with lentiviral expression plasmid and packaging plasmids to produce recombinant lentivirus which titre was checked according to the expression level of green fluorescent protein ( GFP). Bone marrow cells from C57 BL/6 mice were isolated to differentiate into DCs at the present of GM-CSF, IL-4 and LPS for 48 h, then morphology and phenotypic was identified. DCs were infected by recombinant RNAi lentivirus and then the efficiency of infection and the expression of B7-2 on the surface of DCs were detected by flow cytometry. Effects on the proliferation of T cells were detected by co-culturing with DCs which were infected by B7-2 RNAi lentivirus and murine spleen T cells in vitro. Results: DNA sequencing confirmed that three B7-2 RNAi and one non-specific recombinant lentiviral transfer plasmids were successfully constructed, the titer of recombinant lentivirus was ( 2-4) × 108 TU/ml. The recombinant lentivirus could effectively infect DC and inhibit the expression of B7-2. After the B7-2 recombinant lentivirus infection, the ability of DCs to stimulate the proliferation of T cells decreased obviously ( P＜0. 05). Conclusion: The lentiviral B7-2 gene RNAi vector can effectively silence the expression of B7-2 on the surface of DCs and inhibit the proliferation effect of T cells induced by DCs.

GLUT1-mediated effective anti-miRNA21 pompon for cancer therapy

Oncogenic microRNAs are essential components in regulating the gene expression of cancer cells. Especially miR21, which is a major player involved of tumor initiation, progression, invasion and metastasis in several cancers. The delivery of anti-miR21 sequences has significant potential for cancer treatment. Nevertheless, since anti-miR21 sequences are extremely unstable and they need to obtain certain concentration to function, it is intensely difficult to build an effective delivery system for them. The purpose of this work is to construct a self-assembled glutathione (GSH)-responsive system with tumor accumulation capacity for effective anti-miR21 delivery and cancer therapy. A novel drug delivery nanosphere carrying millions of anti-miR21 sequences was developed through the rolling circle transcription (RCT) method. GSH-responsive cationic polymer polyethyleneimine (pOEI) was synthesized to protect the nanosphere from degradation by Dicer or other RNase in normal cells and optimize the pompon-like nanoparticle to suitable size. Dehydroascorbic acid (DHA), a targeting molecule, which is a substrate of glucose transporter 1 (GLUT 1) and highly expressed on malignant tumor cells, was connected to pOEI through PEG, and then the polymer was used for contracting a RNA nanospheres into nanopompons. The anti-miR21 nanopompons showed its potential for effective cancer therapy.

Differential expression of the TwHMGS gene and its effect on triptolide biosynthesis in Tripterygium wilfordii / 中国天然药物

3-Hydroxy-3-methylglutaryl-CoA synthase (HMGS) is the first committed enzyme in the MVA pathway and involved in the biosynthesis of terpenes in Tripterygium wilfordii. The full-length cDNA and a 515 bp RNAi target fragment of TwHMGS were ligated into the pH7WG2D and pK7GWIWG2D vectors to respectively overexpress and silence, TwHMGS was overexpressed and silenced in T. wilfordii suspension cells using biolistic-gun mediated transformation, which resulted in 2-fold increase and a drop to 70% in the expression level compared to cells with empty vector controls. During TwHMGS overexpression, the expression of TwHMGR, TwDXR and TwTPS7v2 was significantly upregulated to the control. In the RNAi group, the expression of TwHMGR, TwDXS, TwDXR and TwMCT visibly displayed downregulation to the control. The cells with TwHMGS overexpressed produced twice higher than the control value. These results proved that differential expression of TwHMGS determined the production of triptolide in T. wilfordii and laterally caused different trends of relative gene expression in the terpene biosynthetic pathway. Finally, the substrate acetyl-CoA was docked into the active site of TwHMGS, suggesting the key residues including His247, Lys256 and Arg296 undergo electrostatic or H-bond interactions with acetyl-CoA.

Mechanism of RNA interference HOXB7 gene expression in colon cancer on pro-liferation and apoptosis of cancer cells / 中国免疫学杂志

Objective:To investigate the effect of inhibiting of HOXB7 gene expression on proliferation and apoptosis of colon cancer cells.Methods:The synthetic negative control siRNA (negative control group) and HOXB7-siRNA (HOXB7 transfection group) were transfected into human colon cancer SW480 cells by LipofectamineTM2000 liposome mediated method,untreated cells as blank group.RT-PCR and Western blot were used to detect the mRNA and protein expression of HOXB7 after transfected 48 h respectively;cell proliferation was detected by CCK8 assay after transfected 24,48,72,96 h;cells apoptosis was detected by flow cytometry after transfected 48 h;the expression of apoptosis related proteins Bcl-2,Bax and Notch1 signaling pathway Notch1 and Hes1 were detected by Western blot.Results:The mRNA and protein expression of HOXB7 in HOXB7 transfected group was significantly lower than that in blank group(P<0.05);OD value was no statistical significance in the three groups after transfected 24 h(P>0.05), while after transfected 48,72,96 h,compared with the control group,OD value in HOXB7 group was significantly decreased(P<0.05);compared with the blank group,the apoptosis rate in HOXB7 transfection group increased significantly,and the expression of Bcl-2, Notch1 and Hes 1 proteins was down regulated,and the expression of Bax protein was up-regulated(P<0.05).Conclusion:RNA inter-ference in the expression of HOXB7 gene in colon cancer can inhibit the proliferation of cancer cells and induce apoptosis by inhibiting of the Notch1 signaling pathway.

Effect on biosynthesis of terpenoid active components through RNA interference with MCT gene in Tripterygium wilfordii / 药学学报

MCT is an important key enzyme in the terpenoid biosynthesis in MEP pathway. In this study, Gateway technology was used to construct RNAi vector of TwMCT, and a vector fragment with a size of 484 bp was obtained. The TwMCT RNAi vector was transferred into the suspension cells of Tripterygium wilfordii by gene gun. Accumulation of terpenoids was assayed by UPLC, and the result showed that the content of triptolide and celastrol in cells decreased by 23.4% and 42.8%, respectively, compared with the control group pK7GWIWG2D. Moreover, the gene expression of TwMCT and major genes in terpenoid biosynthesis pathway was detected by qRT-PCR, which demonstrated that the expression of TwMCT reduced by 29.2% relative to that of the control group pK7GWIWG2D, and the relative expression of TwDXR, TwGGPS, TwHMGR and TwHMGS diminished by 36.3%, 31.3%, 62.2%, and 29.1%, respectively, but the expression of TwDXS was up-regulated by 114.2%, and there was no significant change in TwFPS. Thus, it was verified in vivo that interference with TwMCT expression significantly inhibited the accumulation of triptolide and celastrol in Tripterygium wilfordii, laying a foundation for further exploring the regulation mechanism of MCT gene on the terpenoid biosynthesis in Tripterygium wilfordii.

Analysis of the peanut transgenic offspring with depressing AhFAD2 gene / 生物工程学报

The delta-12 fatty acid desaturase (Δ¹² FAD or FAD2) is a key enzyme that catalyzes oleic acid to linoleic acid by dehydrogenation at Δ¹² position of fatty acid carbon chain. In peanut, reduction or loss of FAD2 activity could enhance the relative content of oleic acid in kernels, and improve the quality and oxidation stability of peanut kernels and products. RNA interference (RNAi) technology could lead to non-expression or down-regulated expression of AhFAD2 gene. We constructed two RNA interference expression vectors with the inverted repeat sequence of partial AhFAD2 gene, which were driven separately by cauliflower mosaic virus (CaMV) 35S promoter or soybean agglutinin lectin seed-specific promoter. Homozygous transgenic lines carrying the two constructs stably in genetics were developed by peanut genetic transformation. There were no significant differences between the transgenic lines and the control through investigating the main agronomic traits. We analyzed the transcriptional level expression of AhFAD2 gene in transgenic lines and the control by real-time fluorescence quantitative PCR (qRT-PCR). The results suggested that the target genes of transgenic lines were likely suppressed by RNA interference, but showed different transcriptional levels in different peanut transgenic lines. Compared with untransformed lines, the resulting down-regulation of AhFAD2 gene resulted in a 15.09% or 36.40% increase in oleic acid content in the seeds of transformed HY23 and FH1 lines respectively, and the content of linoleic acid decreased by 16.19% or 29.81%, correspondingly, the ratio of oleic acid and linoleic acid (O/L) improved by 38.02%, 98.10%. The oleic acid content had significant differences between the two transformation constructs, and also among different transgenic lines. Moreover, the inhibition effect of RNAi was more obvious in the transgenic lines with FH1 as the receptor, and with transformation structure driven by seed specific promoter. The suppressed expression of AhFAD2 gene enabled the development of peanut fatty acid, which indicated that RNA interference would be a reliable technique for the genetic modification of peanut seed quality and the potential for improvement of other traits as well.

Multiple genes contribute to anhydrobiosis (tolerance to extreme desiccation) in the nematode Panagrolaimus superbus

Abstract The molecular basis of anhydrobiosis, the state of suspended animation entered by some species during extreme desiccation, is still poorly understood despite a number of transcriptome and proteome studies. We therefore conducted functional screening by RNA interference (RNAi) for genes involved in anhydrobiosis in the holo-anhydrobiotic nematode Panagrolaimus superbus. A new method of survival analysis, based on staining, and proof-of-principle RNAi experiments confirmed a role for genes involved in oxidative stress tolerance, while a novel medium-scale RNAi workflow identified a further 40 anhydrobiosis-associated genes, including several involved in proteostasis, DNA repair and signal transduction pathways. This suggests that multiple genes contribute to anhydrobiosis in P. superbus.

Construction of an RNAi vector for knockdown of GM-ACS genes in the cotyledonary nodes of soybean

Background: Ethylene plays an important role in the regulation of floral organ development in soybean, and 1-aminocyclopropane-1-carboxylate synthase (ACS) is a rate-limiting enzyme for ethylene biosynthesis. However, whether ACS also regulates floral organ differentiation in soybean remains unknown. To address this, we constructed an RNAi vector to inhibit ACS expression in cotyledonary nodes. Linear DNA cassettes of RNAi-ACS obtained by PCR were used to transform soybean cotyledonary nodes. Results: In total, 131 of 139 transiently transformed plants acquired herbicide resistance and displayed GUS activities in the new buds. In comparison to untransformed seedling controls, a greater number of flower buds were differentiated at the cotyledonary node; GM-ACS1 mRNA expression levels and ethylene emission in the transformed buds were reduced. Conclusion: These results indicate that the cotyledonary node transient transformation system may be suitable for stable transformation and that the inhibition of ACS expression may be an effective strategy for promoting floral organ differentiation in soybean.

Gecko crude peptides inhibit migration and lymphangiogenesis by down regulating the expression of VEGF-C in human hepatocellular carcinoma cells and human lymphatic endothelial cells / 中国药理学与毒理学杂志

OBJECTIVE To explore the role of gecko crude peptides (GCPs) in the proliferation, apoptosis, migration and lymphangiogenesis of human hepatocellular carcinoma cells (HepG2) and human lymphaticendothelial cells (HLECs) in vitro. METHODS The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the anti- proliferative effect of GCPs and siRNA-VEGF-C on HepG2 cells, Hoechst 33258 staining and flow cytometry were performed to analyze cycle and apoptosis. The migration and invasion ability of cells were assayed by transwell chamber experiment and wound-healing assay. The protein and mRNA expressions of vascular endo?thelial growth factor-C (VEGF-C) and CXC chemokine receptor-4 (CXCR4) were detected by q-PCR, immunofluorescence, Western blot. The protein expressions of the extracellular signal regulated kinase (ERKI/2), c-Jun N-terminal kinase (JNK), p38-mitogen activated protein kinases (p38 MAPK), serine/threonine kinase (Akt) and phosphatidylinositol- 3- kinase (PI3K) were detected by western blot. The anti-lymphangiogenesis effect of GCPs on the HLECs was analyzed using an in vitro tube-formation assay. The protein and mRNA expressions of vascular endothelial growth factor receptor-3 (VEGFR-3) and stromal cell-derived factor-1 (SDF-1) were detected by q-PCR, Western blot. RESULTS GCPs and siRNA-VEGF-C inhibited HepG2 proliferation, invasion and migration, and the most obvious inhibitory effect was both synergistic effects. Thus, GCPs suppressed HLECs proliferation, migration and tube-like structure formationin a dose- dependent manner, and had inhibitory effect of tumor- induced lymphangiogenesis in vitro. Additionally, we found that GCPs and siRNA- VEGF- C decreased the expressions of MMP-2, MMP-9, VEGF-C, CXCR4, phospho-ERK1/2, phospho-P38, phospho-JNK and PI3K in HepG2 cells. Moreover, GCPs had a dose-dependent depressive effecton the expressions of VEGFR- 3, SDF- 1 in HLECs. CONCLUSION The low expression of VEGF- C mediated by siRNA-VEGF-C and GCPs inhibit tumor proliferation, invasion and migrationby suppressing the MAPK signaling pathway through reduced levels of VEGF-C, and GCPs inhibit tumor lymphangiogenesis by suppressing the CXCR4/SDF-1 signaling pathway through suppressed VEGF-C/VEGFR-3.

Effect of ionizing radiation on apoptosis of lung cancer H460 cells and its mechansim / 吉林大学学报(医学版)

Objective:To explore the effect of ionizing radiation on apoptosis of lung cancer H460 cells after ATRX was silenced by RNAi and its mechanism.Methods:The lentivirus expression vectors targeting ATRX were transfected into the 293T cells,and the lung cancer H460 cells were infected with lentivirus twice,and the ATRX silenced cell model was obtained after puromycin positive screening,then they were named as sh-ATRX1-H460,sh-ATRX2-H460,and sh-ATRX3-H460 cells;the sh-control-H460 cells were regarded as control cells.The cells were divided into sh-control-H460 group and sh-ATRX3-H460 group,accroding to the silencing results and were irradiated by 0,2 and 8 Gy X-rays.The expression levels of ATRX,poly(ADP-ribose) polymerase 1(PARP1),and caspase-3 proteins were measured by Western blotting method;the apoptotic rate was measured by flow cytometry and AnnexinⅤ-FITC/PI kits.Results:The lung cancer cell model of sh-ATRX3-H460 silenced by ATRX was obtained successfully.After 2 and 8 Gy X-ray irradiation,compared with before irradiation,the expression level of ATRX protein in sh-control-H460 group was increased,while there was no expression of ATRX protein in sh-control-H460 group;compared with before irradiation,the apoptotic rates of cells in two groups were increased(P<0.05 or P<0.01);the apoptotic rate in sh-ATRX3-H460 group was significantly higher than that in sh-control-H460 group after 8 Gy X-ray irradiation (P<0.01).The expressions of cleaved PARP1 in the cells in both two groups after 2 Gy and 8 Gy X-ray irradiation were increased and showed similar rule.The expression level of procaspase-3 protein in sh-control-H460 group had little change,and it was increased significantly in sh-ATRX3-H460 group after 8 Gy X-ray irradiation.Conclusion:ATRX silencing can be achived by RNAi,then the silencing could increase the apoptosis induced by irradiation and its mechanism may be related to the PARP1-caspase-3 pathway.

Effect of Smad3 on cell migration of A549 and HeLa cells / 中国比较医学杂志

Objective To investigate the effect of Smad3 on cell migration of A549 and HeLa cells.Methods Primers for pCMV-Myc-Smad3 plasmid construction and siRNA targeting Smad 3 were designed and synthesized .pCMV-Myc-Smad3 plasmid was constructed with molecular cloning techniques .Overexpression of Smad 3 with Myc-tag or silencing of endogenous Smad3, and then scratch assay was used to detect the migration ability of A 549 and HeLa cells in vitro. Results pCMV-Myc-Smad3 plasmid was successfully constructed .Overexpression of Smad 3 significantly up-regulated the migration rate of A549 and HeLa cells.Conversely, in the same cells, silencing of endogenous Smad3 or treatment with Smad3 inhibitor, SIS3, down-regulated the migration rate .Conclusions Smad3 promotes cell migration of A549 and HeLa cells.

The effect of inhibition of hiwi expression by RNAi on triple negative breast cancer cells MDA-MB-231 through inducing cell apoptosis / 实用医学杂志

Objective To investigate the effect of interfering Hiwi gene on the apoptosis of MDA-MB-231 cells. Methods The mRNA and protein expression of Hiwi mRNA and its target protein were analyzed by qRT-PCR and Western Blot after transfection. MDA-MB-231 cells were divided into 6 groups according to the experimental design. Interference effects were screened as siRNA interference group (Hiwi10330 group), and then divided into 3 groups according to the experimental design: interference group, negative control group/NC, blank control group/Blank. The cell apoptosis rate was detected by flow cytometry after transfection. Results The expression of mRNA in the interference group was significantly lower than that in the siRNA group (P < 0.05), the expression of target protein of Hiwi gene was also significantly inhibited (P < 0.05). The apoptosis rate of MDA-MB-231 cells was significantly higher than that of NC and Blank groups (P<0.05). Conclusion The apoptosis rate of breast cancer cells MDA-MB-231 was significantly increased after siRNA targeting hiwi gene silencing.

Influence on Proliferation and Invasion of Human Breast Carcinoma Cell Line MDA-MB-231 by Using MicroRNA Interference Technique to Suppress MTDH Expression / 医学研究杂志

Objective To investigate the effects of RNA interference technique silencing MTDH on proliferation,metastasis and invasion of human breast cancer cell MDA-MB-231.Methods The MTDH miRNA was transfected into Human breast cancer cell MDA-MB-231 by means of lipofectamine 2000.The silencing efficiency of MTDH was examined by RT-PCR and western blot.The influence of MDA-MB-231 cell proliferation,metastasis and invasion ability from inhibition MTDH gene was conducted by using MTT assay,scratch experiments,and Transwell assay.Results MTDH miRNA effectively inhibited MTDH mRNA and protein levels.The best inhibition rate were 79.41％ and 80.56％ (P ＜ 0.05).With miRNA interferring cells,the ability of cells proliferation was decreased (P ＜ 0.05),and cells invasive and metastasis were depressed (P ＜ 0.05).Conclusion MTDH expression is obviously suppressed after transfected by MTDH miRNA in MDA-MB-231 cells.The inhibition of MTDH expression from microRNA leads to significant suppression of proliferation,invasion and metastasis of breast cancer cell MDA-MB-231.