Publications by authors named "Jinsong Yan"

14 Publications

  • Page 1 of 1

The potential role of miR-124-3p in tumorigenesis and other related diseases.

Mol Biol Rep 2021 Apr 20. Epub 2021 Apr 20.

Carlson School of Chemistry and Biochemistry, Clark University, Worcester, MA, 01610, USA.

MicroRNAs (miRNAs) are a class of single-stranded noncoding and endogenous RNA molecules with a length of 18-25 nucleotides. Previous work has shown that miR-124-3p leads to malignant progression of cancer including cell apoptosis, migration, invasion, drug resistance, and also recovers neural function, affects adipogenic differentiation, facilitates wound healing through control of various target genes. miR-124-3p has been mainly previously characterized as a tumor suppressor regulating tumorigenesis and progression in several cancers, such as hepatocellular carcinoma (HCC), gastric cancer (GC), bladder cancer, ovarian cancer (OC), and leukemia, as a tumor promotor in breast cancer (BC), and it has been also widely studied in a variety of neurological diseases, like Parkinson's disease (PD), dementia and Alzheimer's disease (AD), and cardiovascular diseases, ulcerative colitis (UC), acute respiratory distress syndrome (ARDS). To lay the groundwork for future therapeutic strategies, in this review we mainly focus on the most recent years of literature on the functions of miR-124-3p in related major cancers, as well as its downstream target genes. Although current work as yet provides an incomplete picture, miR-124-3p is still worthy of more attention as a practical and effective clinical biomarker.
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http://dx.doi.org/10.1007/s11033-021-06347-4DOI Listing
April 2021

Homoharringtonine Exerts Anti-tumor Effects in Hepatocellular Carcinoma Through Activation of the Hippo Pathway.

Front Pharmacol 2021 24;12:592071. Epub 2021 Feb 24.

Department of Hematology, Liaoning Key Laboratory of Hematopoietic Stem Cell Transplantation and Translational Medicine, Liaoning Medical Center for Hematopoietic Stem Cell Transplantation, Dalian Key Laboratory of Hematology, Second Hospital of Dalian Medical University, Dalian, China.

Hepatocellular carcinoma (HCC) is the most prevalent subtype of liver cancer with a mortality rate of approximately 3-6/100,000 and is the third leading cause of cancer-related death worldwide. Although several small-molecule drugs have been developed for the treatment of HCC, the choice of an agent for patients who require systemic chemotherapy at an advanced stage is still limited. The Hippo pathway is an evolutionarily conserved tumor suppressive pathway commonly dysregulated in HCC, which makes it a promising target for anti-HCC therapies. Homoharringtonine (HHT) is an FDA-approved anti-leukemia drug with proven strong anti-tumor activity in solid tumors. In this study, we found that HHT could significantly inhibit HCC cell growth by suppressing cell proliferation and colony formation. Moreover, HHT repressed cell invasion and migration remarkably. Additionally, HHT induced cell cycle arrest at S phase and promoted apoptosis. Most importantly, we showed that HHT-induced apoptosis was a consequence of the Hippo pathway activation. Consistently, the MST1/2 inhibitor, XMU-MP-1, could restore cell viability and reverse HHT-induced cell apoptosis. Furthermore, results confirmed the tumor inhibitory effect of HHT. Taken together, our findings suggest that HHT is a potential alternative therapeutic agent for the treatment of HCC.
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http://dx.doi.org/10.3389/fphar.2021.592071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7943857PMC
February 2021

Circular RNA CDR1as disrupts the p53/MDM2 complex to inhibit Gliomagenesis.

Mol Cancer 2020 09 7;19(1):138. Epub 2020 Sep 7.

Department of Neurosurgery, The Second Affiliated Hospital; Institute of Cancer Stem Cell, Cancer Center, Dalian Medical University, Dalian, 116044, Liaoning, People's Republic of China.

Background: Inactivation of the tumor suppressor p53 is critical for pathogenesis of glioma, in particular glioblastoma multiforme (GBM). MDM2, the main negative regulator of p53, binds to and forms a stable complex with p53 to regulate its activity. Hitherto, it is unclear whether the stability of the p53/MDM2 complex is affected by lncRNAs, in particular circular RNAs that are usually abundant and conserved, and frequently implicated in different oncogenic processes.

Methods: RIP-seq and RIP-qPCR assays were performed to determine the most enriched lncRNAs (including circular RNAs) bound by p53, followed by bioinformatic assays to estimate the relevance of their expression with p53 signaling and gliomagenesis. Subsequently, the clinical significance of CDR1as was evaluated in the largest cohort of Chinese glioma patients from CGGA (n = 325), and its expression in human glioma tissues was further evaluated by RNA FISH and RT-qPCR, respectively. Assays combining RNA FISH with protein immunofluorescence were performed to determine co-localization of CDR1as and p53, followed by CHIRP assays to confirm RNA-protein interaction. Immunoblot assays were carried out to evaluate protein expression, p53/MDM2 interaction and p53 ubiquitination in cells in which CDR1as expression was manipulated. After AGO2 or Dicer was knocked-down to inhibit miRNA biogenesis, effects of CDR1as on p53 expression, stability and activity were determined by immunoblot, RT-qPCR and luciferase reporter assays. Meanwhile, impacts of CDR1as on DNA damage were evaluated by flow cytometric assays and immunohistochemistry. Tumorigenicity assays were performed to determine the effects of CDR1as on colony formation, cell proliferation, the cell cycle and apoptosis (in vitro), and on tumor volume/weight and survival of nude mice xenografted with GBM cells (in vivo).

Results: CDR1as is found to bind to p53 protein. CDR1as expression decreases with increasing glioma grade and it is a reliable independent predictor of overall survival in glioma, particularly in GBM. Through a mechanism independent of acting as a miRNA sponge, CDR1as stabilizes p53 protein by preventing it from ubiquitination. CDR1as directly interacts with the p53 DBD domain that is essential for MDM2 binding, thus disrupting the p53/MDM2 complex formation. Induced upon DNA damage, CDR1as may preserve p53 function and protect cells from DNA damage. Significantly, CDR1as inhibits tumor growth in vitro and in vivo, but has little impact in cells where p53 is absent or mutated.

Conclusions: Rather than acting as a miRNA sponge, CDR1as functions as a tumor suppressor through binding directly to p53 at its DBD region to restrict MDM2 interaction. Thus, CDR1as binding disrupts the p53/MDM2 complex to prevent p53 from ubiquitination and degradation. CDR1as may also sense DNA damage signals and form a protective complex with p53 to preserve p53 function. Therefore, CDR1as depletion may play a potent role in promoting tumorigenesis through down-regulating p53 expression in glioma. Our results broaden further our understanding of the roles and mechanism of action of circular RNAs in general and CDR1as in particular, and can potentially open up novel therapeutic avenues for effective glioma treatment.
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http://dx.doi.org/10.1186/s12943-020-01253-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7487905PMC
September 2020

Establishment and characterization of a novel 'double-hit' follicular lymphoma cell line, FL-SJC.

J Cell Mol Med 2020 07 27;24(14):7928-7938. Epub 2020 May 27.

Affiliated Hospital of Jiangsu University, Zhenjiang, China.

About 5 per cent of follicular lymphoma (FL) cases are double-hit (DH) lymphomas. Double-hit follicular lymphoma (DHFL) cell lines can improve our understanding and drug development on FL. But there are only few DHFL cell lines. Here, we established a new MYC/BCL2 DHFL cell line, FL-SJC. The cells were obtained from the hydrothorax of a patient with MYC/BCL2 DHFL and cultured for 140 passages in vitro. FL-SJC cells demonstrated CD19 , CD20 , CD22 , HLA-DR , CD10 , CD38 , Lambda CD23 , CD5 and Kappa . The chromosome karyotypic analysis confirmed the co-existence of t(8;22)(q24;q11) and t(14;18)(q32;q21), as well as additional abnormalities involving chromosomes 2 and 3. Fluorescence in situ hybridization analysis (FISH) showed IGH/BCL2 fusion gene and the MYC rearrangement. In addition, the FL-SJC cells displayed KMT2D/MLL2 and CREBBP gene mutations. After subcutaneous inoculation of FL-SJC cells, the SCID mice developed solid tumour masses within 6-8 weeks. FL-SJC cells were proven to be free of Epstein-Barr (EB) virus infection and be multidrug-resistant. In a conclusion, the FL-SJC cell line has been identified as a novel MYC/BCL2 double-hit follicular lymphoma that can be used as a potentially available tool for the clinical and basic research, together with the drug development for MYC/BCL2 DHFL.
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http://dx.doi.org/10.1111/jcmm.15425DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7348184PMC
July 2020

Integrin β3 Deficiency Results in Hypertriglyceridemia via Disrupting LPL (Lipoprotein Lipase) Secretion.

Arterioscler Thromb Vasc Biol 2020 05 2;40(5):1296-1310. Epub 2020 Apr 2.

From the State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Collaborative Innovation Center of Hematology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, China (B.X., X.X.).

Objective: Integrin β3 is implicated in numerous biological processes such as its relevance to blood triglyceride, yet whether β3 deficiency affects this metabolic process remains unknown. Approach and Results: We showed that the Chinese patients with β3-deficient Glanzmann thrombasthenia had a 2-fold higher serum triglyceride level together with a lower serum LPL (lipoprotein lipase) level than those with an αIIb deficiency or healthy subjects. The β3 knockout mice recapitulated these phenotypic features. The elevated plasma triglyceride level was due to impaired LPL-mediated triglyceride clearance caused by a disrupted LPL secretion. Further analysis revealed that β3 directly bound LPL via a juxtamembrane TIH (threonine isoleucine histidine) motif in its cytoplasmic domain and functioned as an adaptor protein by interacting with LPL and PKD (protein kinase D) to form the PKD/β3/LPL complex that is required for β3-mediated LPL secretion. Furthermore, the impaired triglyceride clearance in β3 knockout mice could be corrected by adeno-associated virus serotype 9 (AAV9)-mediated delivery of wild-type but not TIH-mutated β3 genes.

Conclusions: This study reveals a hypertriglyceridemia in both β3-deficient Chinese patients and mice and provides novel insights into the molecular mechanisms of the significant roles of β3 in LPL secretion and triglyceride metabolism, drawing attention to the metabolic consequences in patients with β3-deficient Glanzmann thrombasthenia.
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http://dx.doi.org/10.1161/ATVBAHA.119.313191DOI Listing
May 2020

Longitudinal whole-genome sequencing reveals the evolution of MPAL.

Cancer Genet 2020 01 22;240:59-65. Epub 2019 Nov 22.

The Second Hospital of Dalian Medical University, Dalian, Liaoning, China. Electronic address:

Purpose: Mixed phenotype acute leukemia (MPAL) is a rare subtype of acute leukemia and its progressive genomic basis over time remains unclear. We aimed to investigate the longitudinal genomic evolution of MPAL from diagnosis to relapse.

Methods: We performed whole genome sequencing (WGS) on bone marrow (BM) samples obtained at the four stages of this disease in a male patient with Philadelphia chromosome positive (Ph+) MPAL, including primary, complete cytogenetic remission (CCR), complete molecular remission (CMR), and relapse stage during the 3 year follow-up period.

Results: 156 single-nucleotide variants (SNVs) and indels were detected, which exhibited distinctive evolutionary behaviors. Seventeen mutations disappeared quickly upon DCTER treatment and never came back. Seven mutations, although disappeared initially, reoccurred with the withdrawal of TKI treatment. Notably, ten mutations emerged in spite of the active DCTER chemotherapy. Moreover, copy number loss played critical roles in monitoring MPAL progression, displaying 7, 0, 0, and 383 losses at the stages of primary, CCR, CMR, and relapse respectively.

Conclusion: This longitudinal genomic investigation of the Ph+ MPAL patient established one MPAL evolution model in which the primary tumor acquired additional variations leading to tumor relapse. Moreover, the event of copy number loss remained a valuable hallmark in the progression of MPAL.
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http://dx.doi.org/10.1016/j.cancergen.2019.11.007DOI Listing
January 2020

Specific Inhibition of CYP4A Alleviates Myocardial Oxidative Stress and Apoptosis Induced by Advanced Glycation End-Products.

Front Pharmacol 2019 9;10:876. Epub 2019 Aug 9.

College of Pharmacy, Dalian Medical University, Dalian, China.

High exposure to advanced glycation end-products (AGEs) may induce cardiotoxicity. However, the effects and mechanisms remain to be further clarified. CYP4A plays an important role in the pathophysiological process of myocardial abnormalities by modulating oxidative stress and apoptosis (OS/Apop) signaling pathway. The present work aimed to investigate whether CYP4A mediates AGEs-induced myocardial injury. AGEs solution was administered intragastrically to C57BL/6 mice for 60 days, while the specific inhibitor of CYP4A, HET0016, was given from the 47th day intraperitoneal injection for 2 weeks. Levels of OS/Apop in heart tissue were measured. The effects on the cell viability and apoptosis were detected in primary rat cardiomyocytes. To further investigate the mechanism, H9c2 cells were treated with HET0016 or small interfering RNAs (siRNAs) against CYP4a mRNA before incubation with AGEs. Exposure to AGEs led to significantly increased expression of CYP4A and levels of OS/Apop in heart and H9c2 cells both and . The OS/Apop pathway was activated with increased expression of NOX2, p-JNK, and cleaved caspase-3 (c-caspase-3) and decreased expression of p-Akt and Bcl-xL both and . Specific CYP4A suppression by HET0016 or siRNA exerted significant protective effects by attenuating AGEs-induced OS/Apop pathways . Our results demonstrate that specific inhibition of CYP4A might be a potential therapeutic option for myocardial injury induced by AGEs.
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http://dx.doi.org/10.3389/fphar.2019.00876DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696796PMC
August 2019

Annexin A2-S100A10 heterotetramer is upregulated by PML/RARα fusion protein and promotes plasminogen-dependent fibrinolysis and matrix invasion in acute promyelocytic leukemia.

Front Med 2017 Sep 8;11(3):410-422. Epub 2017 Jul 8.

Dalian Key Laboratory of Hematology, Liaoning Hematopoietic Stem Cell Transplantation Medical Center, Department of Hematology of the Second Hospital of Dalian Medical University, Dalian, 116027, China.

Aberrant expression of annexin A2-S100A10 heterotetramer (AIIt) associated with PML/RARα fusion protein causes lethal hyperfibrinolysis in acute promyelocytic leukemia (APL), but the mechanism is unclear. To facilitate the investigation of regulatory association between ANXA2 and promyelocytic leukemia/retinoic acid receptor a (PML/RARα) fusion protein, this work was performed to determine the transcription start site of ANXA2 promoter with rapid amplification of 5'-cDNA ends analysis. Zinc-induced U937/PR9 cells expressed PML/RARα fusion protein, and resultant increases in ANXA2 transcripts and translational expressions of both ANXA2 and S100A10, while S100A10 transcripts remained constitutive. The transactivation of ANXA2 promoter by PML/RARα fusion protein was 3.29 ± 0.13 fold higher than that by control pSG5 vector or wild-type RARα. The overexpression of ANXA2 in U937 transfected with full-length ANXA2 cDNA was associated with increased S100A10 subunit, although S100A10 transcripts remained constitutive. The tPA-dependent initial rate of plasmin generation (IRPG) in zinc-treated U937/PR9 increased by 2.13-fold, and cell invasiveness increased by 27.6%. Antibodies against ANXA2, S100A10, or combination of both all remarkably inhibited the IRPG and invasiveness in U937/PR9 and NB4. Treatment of zinc-induced U937/PR9 or circulating APL blasts with all-trans retinoic acid (ATRA) significantly reduced cell surface ANXA2 and S100A10 and associated reductions in IRPG and invasiveness. Thus, PML/RARα fusion protein transactivated the ANXA2 promoter to upregulate ANXA2 and accumulate S100A10. Increased AIIt promoted IRPG and invasiveness, both of which were partly abolished by antibodies against ANXA2 and S100A10 or by ATRA.
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http://dx.doi.org/10.1007/s11684-017-0527-6DOI Listing
September 2017

Virus infection facilitates the development of severe pneumonia in transplant patients with hematologic malignancies.

Oncotarget 2016 Aug;7(33):53930-53940

Department of Hematology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective therapy for patients with hematologic malignancies. Severe pneumonia is associated with high mortality rate in HSCT recipients. Viral co-infection indicates a poor prognosis of HSCT recipients. In this study, a total of 68 allogeneic HSCT recipients were included. Cytomegalovirus (CMV) and Respiratory syncytial virus (RSV) infection was assessed by testing peripheral blood and oropharynx swabs, respectively, collected in the first 180 days after transplantation. We analysed the correlation of CMV and RSV co-infection with severe pneumonia and mortality. The incidence of CMV and RSV co-infection was 26.5% (18/68). Severe pneumonia was diagnosed in 61% (11/18) cases with co-infection compared to only 10% (5/50) cases with mono-infection or no infection. The analysis of potential risk factors for severe pneumonia showed that CMV and RSV co-infection was significantly associated with severe pneumonia (p < 0.001). The 5 patients who died of severe pneumonia were all co-infected with CMV and RSV. In conclusion, CMV and RSV co-infection appears to be an important factor and facilitates the development of severe pneumonia in allogeneic HSCT patients with hematologic malignancies.
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http://dx.doi.org/10.18632/oncotarget.10182DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5288233PMC
August 2016

Chlorpyrifos Induces MLL Translocations Through Caspase 3-Dependent Genomic Instability and Topoisomerase II Inhibition in Human Fetal Liver Hematopoietic Stem Cells.

Toxicol Sci 2015 Oct 20;147(2):588-606. Epub 2015 Jul 20.

*Dalian Key Laboratory of Hematology, Department of Environmental Health and Toxicology, School of Public Health, Dalian Medical University. Dalian, Liaoning, China 116044;

Household pesticide exposure during pregnancy has been associated with a more than 2-fold increased risk in infant leukemia, and chlorpyrifos (CPF) is among the most frequently applied insecticides. During early fetal development, liver is a hematopoietic organ with majority of cells being CD34(+) hematopoietic stem cells (CD34(+)HSC). The in utero injury to CD34(+)HSC has been known to underlie the pathogenesis of several blood disorders, often involving rearrangements of the mixed-lineage leukemia (MLL) gene on 11q23. In this study, we evaluated the leukemogenic potential of CPF in human fetal liver-derived CD34(+)HSC. Specifically, exposure to 10 μM CPF led to decrease in viability, inhibition in proliferation and induction of DNA double-strand breaks (DSBs) and occurrence of MLL(+) rearrangements. In particular, we observed CPF-mediated cell cycle disturbance as shown by G0/G1 arrest, in contrast to etoposide (VP-16), an anticancer drug used as a positive control and known to induce G2/M arrest. Further study on mechanisms underlying DNA DSBs and MLL(+) rearrangements revealed that CPF might act as topoisomerase II poison, a mechanism of action similar to VP-16. On the other hand, CPF was also shown to induce early apoptosis through active caspase-3 activation, a pathway known to underlie DNA DSBs and MLL(+) translocations. Our data indicate that in utero injury of CD34(+)HSC by CPF may contribute to the increased risk of infant leukemia. Future work will elucidate the mechanism and the type of CPF-induced MLL(+) translocations in HSC.
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http://dx.doi.org/10.1093/toxsci/kfv153DOI Listing
October 2015

The role of lysosomes in BDE 47-mediated activation of mitochondrial apoptotic pathway in HepG2 cells.

Chemosphere 2015 Apr 3;124:10-21. Epub 2014 Dec 3.

Dalian Key Laboratory of Hematology, Department of Hematology, The Second Affiliated Hospital of Dalian Medical University, Institute of Stem Cell Transplantation of Dalian Medical University, Dalian 116027, China. Electronic address:

Polybrominated diphenyl ethers (PBDEs) are a group of widely used flame retardants. The rising presence of PBDEs in human tissues has received considerable concerns with regard to potential health risks. While the mitochondrial-apoptotic pathway has been suggested in PBDEs-induced apoptosis, the role of lysosomes is yet to be understood. In the present study, HepG2 cells were exposed to BDE 47 at various concentrations and durations to establish the causal and temporal relationships among various cellular events, such as cell viability, reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis, and expression of cytochrome C and caspase 3. The involvement of lysosomes was simultaneously studied by evaluating lysosomal membrane permeability (LMP) and changes in the expression of cathepsin B, a lysosome hydrolase. In addition, a cathepsin B inhibitor (10 μM CA-074) was used to determine the involvement of lysosomes and potential interactions between lysosomes and mitochondria. Our results showed that ROS production was an initial response of HepG2 to BDE 47 exposure, followed by a decreased MMP; a loss of MMP caused additional ROS generation which acted to induce LMP; an increased LMP resulted in a release of cathepsin B which aggravated the loss of MMP leading to release of cytochrome C and caspase 3 and subsequent apoptosis. Pretreatment with CA-074 did not abolish the initial ROS generation, however, all downstream events were dramatically alleviated. Taken together, our data indicate that lysosomes might be involved in BDE 47-mediated mitochondrial-apoptotic pathway in HepG2 cells, possibly through feedback interactions between mitochondria and lysosomes.
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http://dx.doi.org/10.1016/j.chemosphere.2014.10.054DOI Listing
April 2015

A single course of all-trans retinoic acid plus arsenic trioxide reached a long-term survival in a patient with newly diagnosed acute promyelocytic leukemia: a suggestion for reduction of treatment courses?

Eur J Haematol 2013 Nov 17;91(5):470-1. Epub 2013 Aug 17.

Department of Hematology, the Second Affiliated Hospital of Dalian Medical University, Dalian, China.

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http://dx.doi.org/10.1111/ejh.12177DOI Listing
November 2013

PML/RARalpha fusion protein transactivates the tissue factor promoter through a GAGC-containing element without direct DNA association.

Proc Natl Acad Sci U S A 2010 Feb 3;107(8):3716-21. Epub 2010 Feb 3.

Shanghai Institute of Hematology, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China.

A severe coagulopathy is a life-threatening complication of acute promyelocytic leukemia (APL) and is ascribable mainly to the excessive levels of tissue factor (TF) in APL cells regulated in response to the promyelocytic leukemia/retinoic acid receptor alpha (PML/RARalpha) fusion protein. The underlying molecular mechanisms for this regulation remain ill-defined. With U937-PR9 cell lines stably expressing luciferase reporter gene under the control of different mutants of the TF promoter, both luciferase and ChIP data allowed the localization of the PML/RARalpha-responsive sequence in a previously undefined region of the TF promoter at position -230 to -242 devoid of known mammalian transcription factor binding sites. Within this sequence a GAGC motif (-235 to -238) was shown to be crucial because deletion or mutation of these nucleotides impaired both PML/RARalpha interaction and promoter transactivation. However, EMSA results showed that PML/RARalpha did not bind to DNA probes encompassing the -230 to -242 sequences, precluding a direct DNA association. Mutational experiments further suggest that the activator protein 1 (AP-1) sites of the TF promoter are dispensable for PML/RARalpha regulation. This study shows that PML/RARalpha transactivates the TF promoter through an indirect interaction with an element composed of a GAGC motif and the flanking nucleotides, independent of AP-1 binding.
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http://dx.doi.org/10.1073/pnas.0915006107DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2840450PMC
February 2010

RGT, a synthetic peptide corresponding to the integrin beta 3 cytoplasmic C-terminal sequence, selectively inhibits outside-in signaling in human platelets by disrupting the interaction of integrin alpha IIb beta 3 with Src kinase.

Blood 2008 Aug 8;112(3):592-602. Epub 2008 Apr 8.

State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Ruijin Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.

Mutational analysis has established that the cytoplasmic tail of the integrin beta 3 subunit binds c-Src (termed as Src in this study) and is critical for bidirectional integrin signaling. Here we show in washed human platelets that a cell-permeable, myristoylated RGT peptide (myr-RGT) corresponding to the integrin beta 3 C-terminal sequence dose-dependently inhibited stable platelet adhesion and spreading on immobilized fibrinogen, and fibrin clot retraction as well. Myr-RGT also inhibited the aggregation-dependent platelet secretion and secretion-dependent second wave of platelet aggregation induced by adenosine diphosphate, ristocetin, or thrombin. Thus, myr-RGT inhibited integrin outside-in signaling. In contrast, myr-RGT had no inhibitory effect on adenosine diphosphate-induced soluble fibrinogen binding to platelets that is dependent on integrin inside-out signaling. Furthermore, the RGT peptide induced dissociation of Src from integrin beta 3 and dose-dependently inhibited the purified recombinant beta 3 cytoplasmic domain binding to Src-SH3. In addition, phosphorylation of the beta 3 cytoplasmic tyrosines, Y(747) and Y(759), was inhibited by myr-RGT. These data indicate an important role for beta 3-Src interaction in outside-in signaling. Thus, in intact human platelets, disruption of the association of Src with beta 3 and selective blockade of integrin alpha IIb beta 3 outside-in signaling by myr-RGT suggest a potential new antithrombotic strategy.
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http://dx.doi.org/10.1182/blood-2007-09-110437DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2481538PMC
August 2008