VASP Expression Research Articles

LINC01535 promotes hepatocellular carcinoma proliferation and metastasis by regulating the miR-214-3p/VASP axis.

Background: Emerging evidence has indicated that long noncoding RNAs (lncRNAs) are associated with the development and progression of several carcinomas, including hepatocellular carcinoma (HCC). However, the role of LINC01535 in HCC is still unknown. Materials and methods: In this study, RNA-seq, CCK-8, colony formation, wound healing, Transwell and tumor xenograft assays were used to explore the function of LINC01535 in the proliferation and metastasis of HCC in vitro and in vivo. Fluorescence in situ hybridization (FISH) assay, bioinformatics analysis, dual-luciferase assay, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis were used to reveal the interactions of LINC01535, miR-214-3p and VASP. Results: LINC01535 was overexpressed in HCC tissues and HCC cell lines. Gain- and loss-of-function studies revealed that LINC01535 could promote HCC cell proliferation, migration and invasion both in vitro and in vivo. In addition, upregulation of LINC01535 significantly decreased the expression of microRNA-214-3p (miR-214-3p), which was found closely associated with suppressing tumor progression. Moreover, VASP was identified as a direct downstream target gene of miR-214-3p. LINC01535 positively regulated VASP expression by sponging miR-214-3p, and VASP overexpression activated the PI3K/AKT signaling pathway and stimulated epithelial-to-mesenchymal transition (EMT) in HCC. Conclusions: Our study first found that LINC01535 promoted HCC progression by regulating its downstream target, the miR-214-3p/VASP axis, via the PI3K/AKT signaling pathway. The function and novel regulatory mechanism of LINC01535 may provide a valuable target for the diagnosis and treatment of HCC patients.

Expression of the phagocytic receptors αMβ2 and αXβ2 is controlled by RIAM, VASP and Vinculin in neutrophil-differentiated HL-60 cells.

Activation of the integrin phagocytic receptors CR3 (αMβ2, CD11b/CD18) and CR4 (αXβ2, CD11c/CD18) requires Rap1 activation and RIAM function. RIAM controls integrin activation by recruiting Talin to β2 subunits, enabling the Talin-Vinculin interaction, which in term bridges integrins to the actin-cytoskeleton. RIAM also recruits VASP to phagocytic cups and facilitates VASP phosphorylation and function promoting particle internalization. Using a CRISPR-Cas9 knockout approach, we have analyzed the requirement for RIAM, VASP and Vinculin expression in neutrophilic-HL-60 cells. All knockout cells displayed abolished phagocytosis that was accompanied by a significant and specific reduction in ITGAM (αM), ITGAX (αX) and ITGB2 (β2) mRNA, as revealed by RT-qPCR. RIAM, VASP and Vinculin KOs presented reduced cellular F-actin content that correlated with αM expression, as treatment with the actin filament polymerizing and stabilizing drug jasplakinolide, partially restored αM expression. In general, the expression of αX was less responsive to jasplakinolide treatment than αM, indicating that regulatory mechanisms independent of F-actin content may be involved. The Serum Response Factor (SRF) was investigated as the potential transcription factor controlling αMβ2 expression, since its coactivator MRTF-A requires actin polymerization to induce transcription. Immunofluorescent MRTF-A localization in parental cells was primarily nuclear, while in knockouts it exhibited a diffuse cytoplasmic pattern. Localization of FHL-2 (SRF corepressor) was mainly sub-membranous in parental HL-60 cells, but in knockouts the localization was disperse in the cytoplasm and the nucleus, suggesting RIAM, VASP and Vinculin are required to maintain FHL-2 close to cytoplasmic membranes, reducing its nuclear localization and inhibiting its corepressor activity. Finally, reexpression of VASP in the VASP knockout resulted in a complete reversion of the phenotype, as knock-ins restored αM expression. Taken together, our results suggest that RIAM, VASP and Vinculin, are necessary for the correct expression of αMβ2 and αXβ2 during neutrophilic differentiation in the human promyelocytic HL-60 cell line, and strongly point to an involvement of these proteins in the acquisition of a phagocytic phenotype.

A Peptide Construct Mediates Focal Adhesion Pathway Through the Activation of Integrin Receptor.

The integrin family receptors stimulate the cellular proliferation and migration through the focal adhesion pathway by the activation of PTK2, VASP and TSP1 proteins. The purpose of this study was to investigate the integrin-ligated motifs through the activation of focal adhesion pathway. A chimeric peptide was predicted from the integrin-mediated ligands by bioinformatics tools. The VSMCs were treated with the chimeric peptide and simvastatin. The PTK2, VASP and TSP1 protein and gene expression levels were measured by RT-qPCR and Western Blotting techniques, respectively. AutoDock Tools were used for the docking technique. The PTK2, VASP and TSP1 protein expression levels increased significantly in the VSMCs treated with chimeric peptide in conversely with the effects of simvastatin. The docking results suggested two motifs in the chimeric peptide. In conclusion, the chimeric peptide activated the focal adhesion pathway. The motifs 1 and 2 may be directly involved in the transduction of signal by integrin family receptors.

LncRNA BLACAT1 regulates VASP expression via binding to miR-605-3p and promotes giloma development.

Glioma, an aggressive tumor in brain, presents a very poor prognosis. Emerging evidence has demonstrated that dysfunction of long noncoding RNAs (lncRNAs) is closely related to giloma development. However, the roles of lncRNA BLACAT1 in glioma are not unknown. In this study, we utilized in vitro and in vivo experiments to explore the effects of BLACAT1 on glioma cells. BLACAT1 levels were increased in glioma tissues. Upregulation of BLACAT1 showed poor prognosis. Silencing of BLACAT1 markedly repressed glioma proliferation, migration, and invasion, and suppressed glioma growth in vivo. We also illustrated that BLACAT1 worked as the sponge for miR-605-3p and promoted VASP expression. miR-605-3p was downregulated in glioma and repressed glioma proliferation, migration, and invasion. And VASP is upregulated and contributed to glioma progression. Summarily, this study highlights the important roles of BLACAT1/miR-605-3p/VASP axis in glioma progression.

Effect of Omeprazole on Intestinal Mucosal Barrier After Hemorrhagic Shock in Rats

Objective: The aim of this study was to explain the effect of omeprazole on intestinal mucosal barrier after hemorrhagic shock in rats. Materials and methods: 81 rats were allocated to control, hemorrhagic shock model group and omeprazole group according to random number table, and each group was divided into three subgroups according to the time point of 0, 6, 12 h after HS and resuscitation. The rat model of hemorrhagic shock was induced by using the improved Wiggers method. Model group and omeprazole group were given physiological saline or omeprazole 30 mg/kg retention enema after the post-resuscitation. At three time points, the level of intestinal fatty acid binding protein (IFABP) in the serum was test by ELISA method, and the levels of serum endotoxin (LPS) was detected by dynamic turbidimetric method. The morphological changes of small intestinal mucosa in rats was observed under light microscope, VASP and ZO-1 mRNA expression was measured by RT-qPCR, while p-VASP and ZO-1 protein expression was measured by immunohistochemical method. Results: Compared with model group, serum endotoxin (LPS), fatty acid binding protein (IFABP) content gradually increased (P < 0.05, respectively), and intestinal mucosa damage was aggravate, VASP and ZO-1 gene expression were significantly down-regulation (P < 0.05, respectively) and p-VASP and ZO-1 protein expression were significantly depressed (P < 0.05, respectively). Conclusion: Omeprazole can significantly aggravate the intestinal mucosal barrier function by regulating VAASP and ZO-1 expression after hemorrhagic shock and resuscitation.

CREB1/Lin28/miR-638/VASP Interactive Network Drives the Development of Breast Cancer.

Breast cancer is one of the most common malignant tumors worldwide. Metastasis remains the leading cause of death in breast cancer patients. Research on the mechanism of breast cancer metastasis has become a core issue in breast cancer research. Our previous series of studies have shown that VASP, as a key oncogene, plays an important role in the development of various tumors such as breast cancer. In this study, we find that miR-638 can target to inhibit VASP expression, and Lin28 acts as an RNA-binding protein to regulate the processing of miR-638, which inhibits its maturation and promotes the expression of VASP. In addition, we also find that CREB1 acts as a transcription factor that binds to the promoter of Lin28 gene and activates the Lin28/miR-638/VASP pathway. Furthermore, CREB1 can also directly bind to the promoter of VASP, and activate VASP expression, forming a CREB/Lin28/miR-638/VASP interactive network, which plays an important role in promoting cell proliferation and migration in breast cancer. Our study explained the mechanism of CREB1/Lin28/miR-638/VASP network promoting the development of breast cancer, which further elucidated the mechanism of VASP as a key oncogene, and also provided a theoretical basis for expanding new approaches to tumor biotherapy.

VASP Protein, a Binding Partner Of BCR-ABL and FAK, May Be Implicated In The Chronic Myeloid Leukemia Phenotype

BackgroundVASP (vasodilator-stimulated phosphoprotein) and Zyxin are actin regulatory proteins that control cell-cell adhesion. Zyxin directs actin assembly by interacting and recruiting VASP to specific sites of adhesion. The phosphorylation of VASP modifies their activity in cell-cell junctions. PKA phosphorylates VASP at serine 157 regulating VASP cellular functions. VASP is a substrate of BCR-ABL oncoprotein and is tyrosine-phosphorylated in leukemic cells. However, the function of VASP and Zyxin in hematopoietic cells, in the BCR-ABL pathway and its participation in chronic myeloid leukemia (CML) remains unknown. AimsTo analyze VASP and Zyxin expression in bone marrow cells from CML patients and healthy donors, as well the involvement of these proteins in hematopoietic cell differentiation and in the BCR-ABL signaling pathway. Materials and MethodsVASP and Zyxin expression and phosphorylation were studied in bone marrow samples from 29 individuals (5 healthy donors, 5 CML patients at diagnosis, 16 CML patients responsive to treatment with tyrosine kinase inhibitors (ITK) and 3 CML patients resistant to ITK). One patient was analyzed at diagnosis and after ITK response. VASP or Zyxin silencing was performed by shRNA-lentiviral delivery in K562 cell line, an appropriated shControl was used. ShControl, shVASP and shZyxin K562 cells were induced to megakaryocytic differentiation with 20nM of PMA (phorbol myristate -13 -12 acetate) during 4 days and CD61 expression, a marker for maturing megakaryocytes, was verified by flow cytometry. During megakaryocytic differentiation, VASP and Zyxin gene expressions were evaluated by quantitative PCR; protein expression and activation were determined by Western blotting. Effector proteins of proliferation, apoptosis and adhesion in the BCR-ABL signaling pathway were analyzed in cells silenced for VASP or Zyxin. The interaction of VASP and BCR-ABL or FAK was evaluated by co-immunoprecipiation. ResultsHealthy donors showed p-VASP ser157 expression, in contrast to CML patients at diagnosis who did not present phospho-VASP ser157. After Imatinib treatment CML patients restored VASP phosphorylation however resistant patients maintained this absence. Zyxin showed the same expression in patients and healthy donors. During Imatinib treatment of K562 cells, phospho-VASP ser157 expression was increased and its interaction with BCR-ABL protein was reduced. VASP and Zyxin gene expressions were upregulated during megakaryocyte differentiation of K562 cells (8.7-fold increase, P=0.0115, and 3.6-fold increase, P=0.015, respectively). VASP and Zyxin protein expressions were increased during megakaryocytic differentiation, including the active form of these proteins (p-VASP ser157 and p-Zyxin ser142). VASP silencing in K562 cells resulted in a 40% decrease of CD61 expression at the end of the megakaryocytic differentiation (P<0.05). In addition, VASP and Zyxin silencing resulted in a decrease of BCL-2 and BCL-XL proteins. VASP binds to FAK, an adhesion effector protein of the BCR-ABL pathway, and it´s silencing resulted in a decreased phosphorylation of FAK y925. ConclusionsIn BCR-ABL cells, VASP and Zyxin modulated anti-apoptotic proteins and megakaryocytic differentiation. Hence, the altered expression of VASP activity in CML patients may contribute to the pathogenesis of the disease, affecting cellular differentiation or leukemic cell adhesion. Disclosures:No relevant conflicts of interest to declare.

The Cytoskeleton Proteins VASP and Zyxin Participate in Hematopoiesis and in the BCR-ABL Signaling Pathway.

AbstractAbstract 2780 Background:VASP and Zyxin are cytoskeleton regulatory proteins. They act as a protein complex involved in the signal transduction for actin polymerization, in the control of cell adhesion, cell division and cellular motility. VASP and Zyxin are abnormally expressed in epithelial tumors and are related with tumor progress. VASP is a substrate of the BCR-ABL oncoprotein and is tyrosine-phosphorylated in BCR-ABL leukemic cells. However, the function of VASP and Zyxin in hematopoietic cells and in the BCR-ABL pathway is not yet known; in addition their possible participation in chronic myeloid leukemia (CML) remains an interesting issue to be clarified. Aims:To evaluate the effects of VASP and Zyxin silencing in cell proliferation, apoptosis and differentiation of BCR-ABL K562 cells. Methods:shRNA-lentiviral delivery was used to silence VASP and Zyxin expression in K562 cell line. The shRNA-lentiviral control, VASP and Zyxin cells were treated with different Imatinib concentrations (0, 0.1, 0.5 and 1μM) during 48 hours. Cellular proliferation was measured by MTT assay and apoptosis by flow cytometry with annexin-V. To differentiate cells into megakaryocytes, K562 cells were treated with 20nM of PMA during 4 days and cells were evaluated by the presence of CD61 and CD41 cell markers by flow cytometry. The expression of VASP and Zyxin in cells submitted to megakaryocyte differentiation was evaluated by quantitative PCR and western blotting; protein phosphorylation was also analyzed by western blotting. The interaction of BCR-ABL and VASP after imatinib treatment was evaluated by co-immunoprecipiation. Results:Zyxin silenced cells treated with 0.5μM and 1μM of Imatinib showed a decrease of 17% (P<0.05) and of 22% (P<0.01) in cell proliferation, respectively, compared to the control treated cells. In K562 cells treated with 1μM of Imatinib, VASP and Zyxin silencing increased apoptosis in 21% (P<0.05) and 40% (P<0.05), respectively. VASP and Zyxin gene expressions were upregulated during megakaryocyte differentiation of K562 cells (8.7-fold increase, P=0.0115, and 3.6-fold increase, P=0.015, respectively). In HEL cells (BCR-ABL negative cell line) VASP and Zyxin protein expressions were increased during megakaryocyte differentiation, including the active form of these proteins (phosphorylated VASP serine 157/239 and phosphorylated Zyxin serine 142). VASP silencing in K562 cells resulted in a 40% decrease of CD61 expression at the end of the megakaryocyte differentiation (P<0.05), whereas Zyxin silencing resulted in a 15% decrease of CD41 expression (P<0.01). VASP expression was reduced during Imatinib treatment of K562 cells, as was also its interaction with BCR-ABL protein. In addition, VASP silencing resulted in a decrease of FAK phosphorylation, an effector of the BCR-ABL pathway involved in cellular adhesion of K562 cells. Conclusions:VASP and Zyxin proteins have a role in hematopoiesis, including megakaryocyte differentiation. Alterations in VASP and Zyxin expression affect differentiation and apoptosis of hematopoietic cells. VASP may participate in the BCR-ABL signaling pathway of leukemic cells, affecting leukemic cell adhesion through FAK activity. The elucidation of VASP and Zyxin functions will help elucidate the mechanisms of hematopoietic disorders, such as CML and others. Disclosures:No relevant conflicts of interest to declare.

레스베라트롤의 HT-29 대장암 세포증식 및 이동성 억제효과

Resveratrol, natural polyphenol in grapes and red wine, is known to have the anti-proliferatory and anti-angiogenic effects in various cancer cells. In this study, we have investigated the effects of resveratrol in HT-29 colon cancer cells. Treatment of resveratrol in different concentrations and time inhibited proliferation of HT-29 colon cancer cells. We explored the effects of resveratrol on HT-29 colon cancer cell motility using a wound healing assay. In the absence of the resveratrol, the HT-29 cells are migrated along the edges of the wound and showed a large-scale migration, whereas dose- and time-dependent inhibition of cell flattening and spreading was observed in the presence of resveratrol. Resveratrol inhibited MMP-9 in a dose- and time-dependent on HT-29 colon cancer cells by Western blotting. In addition, resveratrol increased AMPK activity and decreased COX-2, VASP and VEGF expression. Treatment of compound C inhibited AMPK activity, however, the expression of VASP and COX-2 increased thus, COX-2 and VASP are modulated by AMPK. However treatment of celecoxib could not control AMPK activity but decreased VEGF expression. We suggest that resveratrol inhibits cell proliferation and migration through activation of AMPK and decreased COX-2, VASP and VEGF expression in HT-29 colon cancer cells.

MicroRNA‐610: A novel regulator of gastric cancer migration

The main cause of gastric cancer‐related death is more often due to local relapse and long‐distance metastasis. Our previous studies demonstrated that miR‐610, abundantly expressed in normal gastric tissue, showed a significant down‐regulation in SGC‐7901 gastric cancer cells. Conversely, a predicted miR‐610 target, VASP, was over‐expressed in gastric cancer tissue samples. We hypothesized a reciprocal interaction between miR‐610 and VASP. To show this, gastric cancer cells were transfected with a miR‐610 precursor vector to increase endogenous miR‐610 expression. Cell migration was measured by wound healing assay and tumor cell invasion was measured using transwell assay. The interaction between miR‐610 and VASP was ascertained using qPCR, Western Blot and luciferase reporter assays. We demonstrated that ectopic miR‐610 expression reduced the migratory and invasive phenotype of gastric cancer cells. A direct effect of miR‐610 on VASP expression levels was demonstrated at the protein levels via miR‐610 targeting the VASP mRNA 3′‐UTR. In summary, we show that miR‐610 functions as a tumour suppressor miRNA being downregulated in gastric cancer which results in overexpression of VASP. Delivery of miR‐610 into gastric cancer may represent as a novel therapeutic approach to limit gastric cancer metastasis.(The work was supported by the Fundamental Research Funds for the Central Universities No3081006.)

Decreased expression of profilin 2 in oral squamous cell carcinoma and its clinicopathological implications

Profilins are small proteins essential for many normal cellular dynamics and constitute one of the crucial components of actin-based cellular motility. Several recent studies have implicated a role for the profilin (PFN) family in cancer pathogenesis and progression. However, their expression and promising functions are largely unknown in oral squamous cell carcinoma (OSCC). In this study, we analyzed the correlation between PFN1 and PFN2 expression invitro and invivo. The protein expression levels were roughly compared between cell lines (HIOEC, HB96) with the employment of mass spectrometry. PFN2 was singled out as one of the significantly down-regulated genes in the cancerous HB96 cells. The expression levels of PFN1 and PFN2 invitro were validated by RT-PCR, real-time PCR and Western blotting. Laser scanning confocal microscopy was used for the first time to assess the localization of PFN2 expression. In subsequent experiments, we observed the relationship between PFN2 expression levels and the proliferation of transfected HB96 cancer cells. VASP, N-WASP and P27 expression was also examined in the PFN2-transfected or non-transfected HB96 cells. Invivo, antigen expression was determined by immunohistochemical analyses in 88 paired tissue specimens. Decreased protein expression was confirmed in cancerous tissues from 88 OSCC patients compared with paracancerous normal mucous epithelia. Tumors with weak PFN2 expression were associated with a significantly worse prognosis than strongly expressed tumours (P<0.001). Other statistical analyses were performed to assess the differences in expression and their clinical and pathological significance. In conclusion, PFN2 can be utilized as both a potential suppressor marker and a prognostic protein for OSCC. The function of PFN2 may be to regulate the N-WASP/Arp2/3 signaling pathway.

Herpes simplex virus type 1 entry into epithelial MDCKII cells: role of VASP activities

VASP is an actin-regulatory protein that links signalling to remodelling of the cytoskeleton. We investigated the role of VASP during entry of herpes simplex viruses into epithelial MDCKII cells. As VASP functions are regulated by phosphorylations, the phosphorylation pattern was determined upon infection. Phosphorylated VASP decreased temporarily at 15 and 30 min after infection. The impact of phosphorylated VASP was addressed by overexpression of phosphomimetic VASP mutants. Our results revealed that phosphorylated VASP slightly reduced the number of infected cells. Expression studies with deletion mutants further indicated minor effects of VASP on infection efficiency, whereas RNA interference studies demonstrated that reduced VASP expression did not suppress infection. We conclude that VASP activities alone may contribute to herpes simplex virus infection to only a minor extent.

Hepatic VASP upregulation in rats with secondary biliary cirrhosis by expression in the peribiliary vascular plexus

Introduction/aims: Hepatic disorders in patients and animal models may be characterized by increased ductular proliferation and concomitant expansion of the peribiliary vascular plexus (PBP). VASP plays an essential role for the control of cell assembly during the formation of three-dimensional organ structures in the cardiovascular system. Here, we investigated hepatic VASP expression in response to bile duct ligation (BDL) of rats. Methods: BDL was performed in male rats. Sham-operated rats served as controls. After 4 weeks, hepatic VASP expression was assessed by Western-blot analysis and immunohistochemical staining. Results: Livers of BDL rats showed excessive formation of new bile ducts. VASP mRNA and protein expression was upregulated in whole liver homogenates from BDL rats. This upregulation was located to the expanding PBP in the areas of ductular proliferation. In patients with cirrhosis, hepatic VASP expression was upregulated compared to non-cirrhotic patients. Discussion: VASP may play a role for vascular morphogenesis in the expanding PBP of BDL rats.

0013 Effect of RNA interference mediated inhibition of VASP expression level on migration and invasion of human mammary epithelial tumor cells

0013 Effect of RNA interference mediated inhibition of VASP expression level on migration and invasion of human mammary epithelial tumor cells

0005 Epigallocatechin-3-gallate decreases VASP expression and MCF-7 cells invasion by inhibiting Rac1 activity

We investigated whether hypermethylation identifies breast cancers with distinctive clinical and pathological features. Methods: We evaluated the methylation of RASSF1A, SYK, DAPK, ER-a, BRCA1, CCND2, p16, TMS1, ITIH5 and APC in 95 breast carcinomas using methylation-specific PCR. Results: Methylation frequencies ranged from 9.1% for SYK to 95.8% for RASSF1A. For all age patients, tumors with CCND2 methylation were associated with triple negative (OR=1.34, CI: 1.165−1.541). However, tumors of patient’s age younger than 50 with BRCA1 methylation were associated with ER (OR=7, CI: 1.277−38.358) or PR negative (OR=11.07, CI: 1.245–98.598). And DAPK methylation was associated p53 mutation (OR=2.714, CI: 1.507−4.890). Nevertheless, for patient’s age older than 50, tumors with ITIH5 and BRCA1 methylation were associated with more advanced t stage (t0−1/t2−4, ITIH5 OR= 0.283, CI= 0.088−0.910; BRCA1 OR= 0.3, CI= 0.095−0.948) and the methylation of APC was associated with PR negative (OR=4.52, CI= 1.203−16.967). Conclusion: Our data suggests that gene methylation may be linked to various pathological features of breast cancer. Furthermore, the different methylation profile in tumors of different age patient population may imply different carcinogenesis pathway, however, this requires confirmation in larger studies.

Inhibitive effect of EGCG on MCF‐7 cell migration and invasion

Epidemiological studies have described the beneficial effects of dietary green tea on the reduction of the risk of breast cancer. We surveyed the role of green tea catechin epigallocatechin gallate (EGCG) in the metastasis of MCF‐7 cell and analyzed the possible mechanism of EGCG's ability to inhibit breast cancer metastasis. To determine the effect of EGCG on the migration of MCF‐7 cells, we used would‐healing assay. The results show that the cell migration velocity was reduced by EGCG at 50μg/mL (P&lt;0.05). In transwell invasion assay, the EGCG group showed lower invasion capacity than the control group significantly (P&lt;0.05). The activity of Rac1 pathway decreased after treating with EGCG, which was estimated by GST pull‐down assay. On the contrary, the expression level of VASP was incresaed by Rac activator fMLP, while migration velocity of MCF‐7 cells was increased significantly. Furthermore, the result revealed that knockdown of Rac1 by siRNA decreased the expression of VASP. Thus, our study demonstrated the inhibitive effect of EGCG on MCF‐7 cell migration and invasion, which may be produced by down regulated of VASP expression level via Rac1 pathway. (This work was supported by National Natural Sciences Foundation of China under Grant No.30770966)

Role of the T744C polymorphism of the P2Y12 gene on platelet response to a 600-mg loading dose of clopidogrel in 597 patients with non-ST-segment elevation acute coronary syndrome

Background Variability in platelet response to clopidogrel and its clinical relevance have been well described. However, the underlying mechanisms remain unclear. Recently, the T744C polymorphism of the P2Y12 receptor gene has been associated with enhanced platelet aggregation in healthy volunteers, suggesting a possible mechanism for modulation of clopidogrel response. Aim of this study To assess whether the clopidogrel response may be influenced by the T744C P2Y12 gene polymorphism in patients with non ST elevation acute coronary syndrome (NSTE ACS). Methods 597 NSTE ACS patients were included in our study and were divided into 3 groups: CC homozygotes, CT heterozygotes ad TT homozygotes. All patients received loading doses of 600 mg clopidogrel and 250 mg aspirin at least 12 hours before blood samples. Clopidogrel response was assessed by post-treatment ADP 10 μmol/L-induced platelet aggregation (ADP-Ag), VASP phosphorylation (PRI VASP) and P-selectin expression (PS). Clopidogrel resistance was defined by persistence of High Post-treatment Platelet Reactivity (HPPR = ADP-Ag > 70%). Results Significant variability in the distribution of platelet parameters was observed in the overall study population. No significant difference in platelet parameter profiles was observed within patients having the same genotype, for ADP-Ag ( p = 0.39), PRI VASP ( p = 0.97) and PS ( p = 0.62). The genotype frequencies of the T744C polymorphism of the P2Y12 gene were similar in responders and non responders defining by HPPR ( p = 0.75). Conclusion Our study did not show any influence of the T744C polymorphism of the P2Y12 receptor gene on clopidogrel response assessed by ADP-Ag, PRI VASP or P-selectin expression in NSTE ACS patients.

Lack of association between the 807 C/T polymorphism of glycoprotein Ia gene and post-treatment platelet reactivity after aspirin and clopidogrel in patients with acute coronary syndrome

Variability in platelet response to antiplatelet therapy and its clinical relevance have been well described. However, the underlying mechanisms remain unclear. It was the aim of the present study to assess whether the response to aspirin and clopidogrel may be influenced by the 807 C/T polymorphism of the glycoprotein Ia (GpIa) gene in patients with non-ST elevation acute coronary syndrome (NSTE ACS). Six hundred one NSTE ACS patients were included in our study and were divided into three groups: CC homozygotes, CT heterozygotes ad TT homozygotes. All patients received loading doses of 600 mg clopidogrel and 250 mg aspirin at least 12 hours before blood samples were drawn. Post-treatment platelet reactivity was assessed by post treatment ADP 10 microM-induced platelet aggregation (ADP-Ag), VASP phosphorylation (PRI VASP) and P-selectin expression. Non-response to dual antiplatelet therapy was defined by high post-treatment platelet reactivity (HPPR=ADP-Ag > 70%). Significant variability in the distribution of platelet parameters was observed in the overall study population. No significant difference in platelet parameters profiles was observed within patients having the same genotype, for ADP-Ag (p=0.33), PRIVASP (p=0.72) and P-selectin expression (p=0.37). The genotype frequencies of the 807 C/T polymorphism of the GpIa gene were similar in responders and non-responders defined by persistent HPPR (p=0.104). In conclusion, our study did not show any influence of 807 C/T polymorphism of GpIa gene on post-treatment platelet reactivity assessed by ADP-Ag, PRI VASP or P-selectin expression in 601 NSTE ACS patients.