槲皮素下调hTERT表达对肝癌HepG2细胞生长影响研究

目的观察槲皮素对肝癌HepG2细胞生长及对hTERT基因表达的影响。方法以台盼蓝拒染法计数肝癌细胞的生长抑制率,透射电镜从形态变化上了解凋亡的发生,流式细胞术检测细胞周期变化,western-blot、RT-PCR检测hTERT基因表达改变,PCR-TRAP法检测端粒酶活性。结果台盼蓝拒染法计数显示槲皮素抑制肝癌HepG2细胞增殖的作用明显,且呈浓度和时间依赖性,槲皮素处理48h后的Ic50为25.5μm。形态学检测显示出细胞凋亡的特征变化,流式细胞仪检测表明经10～20μm/L的槲皮素处理,肝癌HepG2细胞周期阻滞于G0/G1期,且HepG2细胞hTERT蛋白和mRNA表达降低,端粒酶活性受抑制。结论槲皮素能抑制肝癌细胞的生长,呈时间、剂量依赖性,能诱导HepG2细胞发生凋亡,其抑制增生与诱导凋亡的机制可能与下调hTERT基因表达,抑制端粒酶活性,破坏端粒稳定性有关。

shRNA表达载体构建方法的优化

目的探讨shRNA表达载体的构建方法 ,以加速RNA干扰研究的进程。方法对shRNA表达载体的构建过程进行分析和监测 ,并加以优化。结果发现shRNA表达载体构建的退火过程容易产生障碍 ,经优化退火缓冲液的NaCl含量后 ,能明显提高退火效率及shRNA表达载体构建的成功率。结论shRNA表达载体构建的退火过程需加以关注 ,退火缓冲液中NaCl含量应提高至 2 0

RNA干扰抑制结肠癌细胞血管内皮生长因子表达

目的:应用RNA干扰技术抑制结肠癌血管内皮生长因子(VEGF)表达。方法:将VEGF基因作为RNA干扰的靶区,通过E-RNAi网上提供的服务,设计两个特异的RNA干扰序列,将其装入含U6启动子的载体上,构建成抗VEGF基因的小发夹样RNA(shRNA)表达载体,再转染人结肠癌细胞HT29,通过RT-PCR、Northern blotting、免疫荧光和Western blotting,观察VEGF表达受抑的程度。结果:成功构建了两种抗VEGF基因的shRNA表达载体,RT-PCR、Northern blotting、免疫荧光和Western blotting,均发现其能明显抑制HT29细胞VEGF基因的表达,抑制率分别达42%、88%、73%和82%。结论:针对VEGF基因的shRNA表达载体能够明显抑制结肠癌细胞VEGF基因的表达。

丙型肝炎病毒核心基因重组腺病毒的构建、鉴定与表达

目的构建HCV C基因重组腺病毒,以期用于HCV C蛋白的功能研究。方法以含有丙肝病毒1b亚型核心基因的质粒pcDNA3.1/HCV-C为模板,PCR扩增HCV C基因,PCR产物双酶切后亚克隆至穿梭质粒pAdTrack-CMV上,与骨架质粒pAdEasy-1在BJ5183细菌内同源重组,获得重组腺病毒质粒pAd-C,PacⅠ酶切线性化后脂质体法转染293细胞进行包装,获得重组腺病毒Ad-C,继之在293细胞内扩增,利用报告基因GFP监测病毒滴度和感染效率,Western blot检测HCV C蛋白的表达。结果PCR及Western blot结果均证实重组腺病毒Ad-C构建成功。结论成功构建了重组腺病毒Ad-C,为进一步研究核心蛋白的生物学功能奠定了基础。

抑制Dicer基因对shRNA功能发挥的影响

本文将Dicer基因的RNA酶III结构域作为靶区,设计并构建了两个抗Dicer基因的小发夹样RNA(shRNA)表达载体,将其转染2215、结肠癌TC细胞和基因组中整合有绿色荧光蛋白基因(GFP)的HepG2A9细胞,通过RT-PCR评价RNA干扰抑制Dicer基因表达的效率;当HepG2A9细胞Dicer基因表达被上述RNA干扰抑制时,再转染抗GFP的shRNA表达载体,通过RT-PCR和荧光显微镜观察GFP表达水平。结果显示,在不同细胞系中,这两个抗Dicer基因shRNA表达载体,均能明显抑制Dicer基因的表达;当Dicer基因受抑时,后续转染抗GFP的shRNA表达载体不能有效抑制GFP的表达。结果表明,抗Dicer基因shRNA表达载体,能够明显抑制Dicer基因的表达;shRNA表达载体的功能发挥需要Dicer酶的直接参与。

BMP signaling in mesenchymal stem cell differentiation and bone formation

Bone morphogenetic proteins (BMPs) are members of the TGF-β superfamily and have diverse functions during development and organogenesis. BMPs play a major role in skeletal development and bone formation, and disruptions in BMP signaling cause a variety of skeletal and extraskeletal anomalies. Several knockout models have provided insight into the mechanisms responsible for these phenotypes. Proper bone formation requires the differentiation of osteoblasts from mesenchymal stem cell (MSC) precursors, a process mediated in part by BMP signaling. Multiple BMPs, including BMP2, BMP6, BMP7 and BMP9, promote osteoblastic differentiation of MSCs both in vitro and in vivo. BMP9 is one of the most osteogenic BMPs, yet it is a poorly characterized member of the BMP family. Several studies demonstrate that the mechanisms controlling BMP9-mediated osteogenesis differ from other osteogenic BMPs, but little is known about these specific mechanisms. Several pathways critical to BMP9-mediated osteogenesis are also important in the differentiation of other cell lineages, including adipocytes and chondrocytes. BMP9 has also demonstrated translational promise in spinal fusion and bone fracture repair. This review will summarize our current knowledge of BMP-mediated osteogenesis, with a focus on BMP9, by presenting recently completed work which may help us to further elucidate these pathways.

RNA interference-mediated gene silencing of vascular endothelial growth factor in colon cancer cells

瞄准：由 RNA 干扰(RNAi ) 在结肠癌房间线禁止脉管的内皮生长因素(VEGF ) 的表示。方法：跟随了 E-RNAi 的服务，我们设计了并且构造了二种 shRNA 表示向量瞄准 VEGF 基因，然后 transfected 他们进由 lipofectamineTM 的结肠癌 HT29 房间 2000。VEGF mRNA 的水平被 RT-PCR 并且北弄污调查。VEGF 的蛋白质表示被 immunofluoresence 染色并且西方的弄污观察。结果：我们得到了能高效地在 HT29 房间禁止 VEGF 的表示的二种 VEGF 特定的 shRNA 表示向量。RT-PCR，北弄污， immunofluoresence 染色并且西方的弄污证明为 VEGF 表示的那抑制率分别地直到 42% ， 89% ， 73% 和 82% 。结论：VEGF 的表示能被 RNA 干扰在 HT29 房间禁止。

Molecular pathogenesis and therapeutic strategies of human osteosarcoma

Osteosarcoma（OS）is a devastating illness with rapid rates of dissemination and a poor overall prognosis,despite aggressive standard-of-care surgical techniques and combination chemotherapy regimens.Identifying the molecular mechanisms involved in disease pathogenesis and progression may offer insight into new therapeutic targets.Defects in mesenchymal stem cell differentiation,abnormal expression of oncogenes and tumor suppressors,and dysregulation within various important signaling pathways have all been implicated in development of various disease phenotypes.As such,a variety of basic science and translational studies have shown promise in identifying novel markers and modulators of these disease-specific aberrancies.Born out of these and similar investigations,a variety of emerging therapies are now undergoing various phases of OS clinical testing.They broadly include angiogenesis inhibitors,drugs that act on the bone microenvironment,receptor tyrosine kinase inhibitors,immune system modulators,and other radio-or chemo-sensitizing agents.As new forms of drug delivery are being developed simultaneously,the possibility of targeting tumors locally while minimizing systemic toxicityis is seemingly more achievable now than ever.In this review,we not only summarize our current understanding of OS disease processes,but also shed light on the multitude of potential therapeutic strategies the scientific community can use to make long-term improvements in patient prognosis.

The evolving roles of Wnt signaling in stem cell proliferation and differentiation, the development of human diseases, and therapeutic opportunities

The evolutionarily conserved Wnt signaling pathway plays a central role in develop-ment and adult tissue homeostasis across species.Wnt proteins are secreted,lipid-modified signaling molecules that activate the canonical(β-catenin dependent)and non-canonical(β-catenin independent)Wnt signaling pathways.Cellular behaviors such as proliferation,differ-entiation,maturation,and proper body-axis specification are carried out by the canonical pathway,which is the best characterized of the known Wnt signaling paths.Wnt signaling has emerged as an important factor in stem cell biology and is known to affect the self-renewal of stem cells in various tissues.This includes but is not limited to embryonic,hematopoietic,mesenchymal,gut,neural,and epidermal stem cells.Wnt signaling has also been implicated in tumor cells that exhibit stem cell-like properties.Wnt signaling is crucial for bone formation and presents a potential target for the development of therapeutics for bone disorders.Not surprisingly,aberrant Wnt signaling is also associated with a wide variety of diseases,including cancer.Mutations of Wnt pathway members in cancer can lead to unchecked cell proliferation,epithelial-mesenchymal transition,and metastasis.Altogether,advances in the understand-ing of dysregulated Wnt signaling in disease have paved the way for the development of novel therapeutics that target components of the Wnt pathway.Beginning with a brief overview of the mechanisms of canonical and non-canonical Wnt,this review aims to summarize the cur-rent knowledge of Wnt signaling in stem cells,aberrations to the Wnt pathway associated with diseases,and novel therapeutics targeting the Wnt pathway in preclinical and clinical studies.

Canonical and noncanonical Wnt signaling: Multilayered mediators, signaling mechanisms and major signaling crosstalk

Wnt signaling plays a major role in regulating cell proliferation and differentiation.The Wnt ligands are a family of 19 secreted glycoproteins that mediate their signaling effects via binding to Frizzled receptors and LRP5/6 coreceptors and transducing the signal either throughβ-catenin in the canonical pathway or through a series of other proteins in the nonca-nonical pathway.Many of the individual components of both canonical and noncanonical Wnt signaling have additional functions throughout the body,establishing the complex interplay between Wnt signaling and other signaling pathways.This crosstalk between Wnt signaling and other pathways gives Wnt signaling a vital role in many cellular and organ processes.Dys-regulation of this system has been implicated in many diseases affecting a wide array of organ systems,including cancer and embryological defects,and can even cause embryonic lethality.The complexity of this system and its interacting proteins have made Wnt signaling a target for many therapeutic treatments.However,both stimulatory and inhibitory treatments come with potential risks that need to be addressed.This review synthesized much of the current knowl-edge on the Wnt signaling pathway,beginning with the history of Wnt signaling.It thoroughly described the different variants of Wnt signaling,including canonical,noncanonical Wnt/PCP,and the noncanonical Wnt/Ca2+pathway.Further description involved each of its components and their involvement in other cellular processes.Finally,this review explained the various other pathways and processes that crosstalk with Wnt signaling.

Long noncoding RNA(lncRNA)H19:An essential developmental regulator with expanding roles in cancer,stem cell differentiation,and metabolic diseases

Recent advances in deep sequencing technologies have revealed that,while less than 2%of the human genome is transcribed into mRNA for protein synthesis,over 80%of the genome is transcribed,leading to the production of large amounts of noncoding RNAs(ncRNAs).It has been shown that ncRNAs,especially long non-coding RNAs(lncRNAs),may play crucial regulatory roles in gene expression.As one of the first isolated and reported lncRNAs,H19 has gained much attention due to its essential roles in regulating many physiological and/or pathological processes including embryogenesis,development,tumorigenesis,osteogen-esis,and metabolism.Mechanistically,H19 mediates diverse regulatory functions by serving as competing endogenous RNAs(CeRNAs),Igf2/H19 imprinted tandem gene,modular scaffold,cooperating with H19 antisense,and acting directly with other mRNAs or lncRNAs.Here,we summarized the current understanding of H19 in embryogenesis and development,cancer development and progression,mesenchymal stem cell lineage-specific differentiation,and metabolic diseases.We discussed the potential regulatory mechanisms underlying H19’s func-tions in those processes although more in-depth studies are warranted to delineate the exact molecular,cellular,epigenetic,and genomic regulatory mechanisms underlying the physiolog-ical and pathological roles of H19.Ultimately,these lines of investigation may lead to the development of novel therapeutics for human diseases by exploiting H19 functions.

Niclosamide(NA)overcomes cisplatin resistance in human ovarian cancer

Ovarian cancer(OC)is one of the most lethal malignancies of the female reproduc-tive system.OC patients are usually diagnosed at advanced stages due to the lack of early diag-nosis.The standard treatment for OC includes a combination of debulking surgery and platinum-taxane chemotherapy,while several targeted therapies have recently been approved for maintenance treatment.The vast majority of OC patients relapse with chemoresistant tu-mors after an initial response.Thus,there is an unmet clinical need to develop new therapeu-tic agents to overcome the chemoresistance of OC.The anti-parasite agent niclosamide(NA)has been repurposed as an anti-cancer agent and exerts potent anti-cancer activities in human cancers including OC.Here,we investigated whether NA could be repurposed as a therapeutic agent to overcome cisplatin-resistant(CR)in human OC cells.To this end,we first established two CR lines SKOV3CR and OVCAR8CR that exhibit the essential biological characteristics of cisplatin resistance in human cancer.We showed that NA inhibited cell proliferation,sup-pressed cell migration,and induced cell apoptosis in both CR lines at a low micromole range.Mechanistically,NA inhibited multiple cancer-related pathways including AP1,ELK/SRF,HIF1,and TCF/LEF,in SKOV3CR and OVCAR8CR cells.NA was further shown to effectively inhibit xenograft tumor growth of SKOV3CR cells.Collectively,our findings strongly suggest that NA may be repurposed as an efficacious agent to combat cisplatin resistance in chemoresistant hu-man OC,and further clinical trials are highly warranted.

Corrigendum to ‘Modeling colorectal tumorigenesis using the organoids derived from conditionally immortalized mouse intestinal crypt cells (ciMICs)’ [Genes Dis 8 (2021) 814-826]

The authors regret that an image assembly(copy/paste)error in Figure 3D,in which the image for the organoid of"Primary MiCs"group was erroneously duplicated with an image of primary MICs that was previously published.The corrected figure is shown below.As shown in the corrected Figure 3D,this error does not adversely impact the conclusion of the original work.The authors would like to apologise forany inconvenience caused.

Corrigendum to “Establishment and functional characterization of the reversibly immortalized mouse glomerular podocytes (imPODs)” [Genes & Diseases 5 (2018) 137–149]

The authors regret having an image assembly error in Figure 3A,in which the image for "imPOD Synaptopodin DAPl stain"groupwas erroneouslyduplicatedwiththe imagefrom the"tsPOD-33C SynaptopodinDAPIstain"group.We confirm the error is restricted to the image assembly,and the underlying data and conclusions are correct and unchanged.The authors would like to apologize for any inconvenience caused.

Bone Morphogenic Protein 9(BMP9)/Growth Differentiation Factor 2(GDF2)modulates mouse adult hippocampal neurogenesis by regulating the survival of early neural progenitors

Adult neurogenesis occurs in two specialized regions of the mammalian brain,the subventricular zone(SVZ)and the subgranular zone(SGZ)of the dentate gyrus(DG).^(1)Adult hippocampal neural stem cells(NSCs),referred to as Type 1 cells represented by radial glia-like cells(RGLs),generate Type 2 cells that are divided into Type 2a and Type 2 b subpopulations,the latter of which give rise to Type 3 cells(neuroblasts).

Engineered nucleus-free mesenchymal stem cells (MSCs) for the targeted delivery of therapeutics to disease site

Specialized therapeutic delivery, or use of pharmaceuticals and other biomaterials to target specific parts of the body or diseased tissue, has long been sought as an ideal way of treating human diseases. A recent article published in Nature Biomedical Engineering revealed an innovative strategy to engineer nucleus-free human mesenchymal stem cells (MSCs) for targeted delivery of therapeutics to disease site.1 MSCs have emerged as promising vehicles of therapeutic delivery.2,3 MSCs are undifferentiated pluripotent stem cells derived from areas such as bone marrow and adipose tissue.4,5 MSCs are sought after for their chemotaxis, or ability to home towards a chemical stimulus, and capacity for modification with elements such as chemoattractant receptors and adhesion molecules.1 These properties allow for site-specific and minimally-invasive therapeutic administration and treatment.

Corrigendum to “The development of a sensitive fluorescent protein-based transcript reporter for high throughput screening of negative modulators of lncRNAs” [Genes & Diseases 5 (2018) 62–74]

The authors regret having an image assembly error in Figure 5Ca,in which the image for the "Oh dBiFP-AdRFp"group was erroneously duplicated with an overlapping image from the"36h BiFP dBIFP-AdR-simH19"group.We confirm the error is restricted to the image assembly,and the underlying data and conclusions are correct and unchanged.The authors would like to apologize for any inconvenience caused.

Corrigendum to “Characterization of the essential role of bone morphogenetic protein 9 (BMP9) in osteogenic differentiation of mesenchymal stem cells (MSCs) through RNA interference” [Genes & Diseases 5(2018):172–184]

The authors regret having several image assembly errors.Specifically,in Figure 3A panel b,the image for "AdsimB9-4 only"group was erroneously duplicated with an overlapping image from the"AdRFp"group;and the image for"AdsimB9-1+BMP9"groupwas erroneouslyduplicatedwithan overlapping image from"AdsimB9-8+BMP9"group.In Figure 4Apanel a,the images for"BMP9"group and "BMP9+simB9-4"group were erroneously duplicated with an overlapping image from"simB9-4"group.In Figure 5A,the image for"BMP9+simB9-4/Day3"group was erroneously duplicated with an overlapping image from"BMP9+simB9-7/Day3"group;and the image for"BMP9+simB9-4/Day5"group was erroneously duplicated with an overlapping image from an unrelated experiment.In Figure 6B,the image for"BMP9+simB9-7/Day 11"group was erroneously duplicated with an overlapping image from the"BMP9+simB9-4/Day 11"group.

Corrigendum to “Sox9 augments BMP2-induced chondrogenic differentiation by downregulating Smad7 in mesenchymal stem cells (MSCs)” [Genes & Diseases 4 (2017) 229–239]

The authors regret having image assembly errors in Figure 1A and Figure 3A.Specifically,in Figure 1A,the images for"C3H10T1/2",""BMP2"and"Sox9"were erroneously duplicated with the images from an irrelevant experiment that was conducted at the same time.In Figure 3A,the images for"Col2a1"and"β-actin"were erroneously duplicated with the images from an irrelevant experiment that was conducted at the same time.

SV40 large T antigen-induced immortalization reprograms mouse cardiomyocyte progenitors with mesenchymal stem cell characteristics and osteogenic potential

While progenitor cell-based cardiomyocyte regeneration holds great promise of repairing an injured heart,primary cardiomyogenic progenitors(CPs)have a limited life span in culture,hampering the use of CPs for in vitro and in vivo studies.We previously isolated primary CPs from mouse E15.5 fetal heart,and reversibly immortalized them with SV40 large T antigen(SV40 LTA),resulting in immortalized CPs(iCPs),which maintain long-term proliferation and ex-press cardiomyogenic markers and retain differentiation potential under appropriate differentiation conditions.