RGD peptide inhibits tumor growth by affecting angiogenesis related signaling pathway of laryngeal cancer stem cells / El péptido RGD inhibe el crecimiento tumoral al afectar la vía de señalización relacionada con la angiogénesis de las células madre del cáncer de laringe

SUMMARY: This study is to investigate the role and mechanism of RGD peptide in laryngeal cancer stem cells (CSCs). Laryngeal cancer CD133+Hep-2 CSCs were sorted by flow cytometry. RGD peptide was co-cultured with sorted laryngeal CSCs. Cell proliferation was detected with CCK-8 assay. The mRNA levels of VEGF/VEGFR2/STAT 3/HIF-1α were detected with RT-PCR. The proteins of VEGF/ VEGFR2/STAT 3/HIF-1α were detected with Western blot. The sorted CSCs were inoculated into nude mice. Tumor volume was measured. Integrin αvβ3 expression in tumor tissues was analyzed with immunohistochemistry. The results showed that the ratio of CD133+ CSCs to the total number of cells was 1.34±0.87 %, while CD133-non-tumor stem cells accounted for 95.0±5.76 %. The sorted cancer stem cells grew well. The RGD peptide significantly inhibited the proliferation of CD133+Hep-2 laryngeal CSCs in a dose-dependent manner. The RGD peptide significantly inhibited the mRNA of VEGFR2, STAT3 and HIF-1α in laryngeal CSCs in a concentration-dependent manner. Consistently, the RGD peptide significantly inhibited the protein expression of VEGFR2, STAT3 and HIF-1α in laryngeal CSCs in a dose-dependent manner. At the same time, in vivo tumor experiments showed that the RGD peptide significantly inhibited tumor volume but not the body weight. Furthermore, RGD peptide significantly inhibited the expression of tumor angiogenesis-related protein integrin αvβ3. Our findings demonstrate that RGD peptide inhibits tumor cell proliferation and tumor growth. The underlying mechanism may that RGD inhibits tumor angiogenesis-related signaling pathways, thus affecting the tumor angiogenesis, and decreasing the progression of human laryngeal CSCs.

Este estudio se realizó para investigar el papel y el mecanismo del péptido RGD en las células madre del cáncer de laringe (CSC). Las CSC CD133+Hep-2 de cáncer de laringe se clasificaron mediante citometría de flujo. El péptido RGD se cocultivó con CSC laríngeas clasificadas. La proliferación celular se detectó con el ensayo CCK-8. Los niveles de ARNm de VEGF/VEGFR2/ STAT 3/HIF-1α se detectaron con RT-PCR. Las proteínas de VEGF/ VEGFR2/STAT 3/HIF-1α se detectaron con Western blot. Las CSC clasificadas se inocularon en ratones nudos. Se midió el volumen del tumor. La expresión de integrina αvβ3 en tejidos tumorales se analizó con inmunohistoquímica. Los resultados mostraron que la proporción de CSC CD133+ con respecto al número total de células fue de 1,34 ± 0,87 %, mientras que las células madre no tumorales CD133 representaron el 95,0 ± 5,76 %. Las células madre cancerosas clasificadas crecieron bien. El péptido RGD inhibió significativamente la proliferación de CSC laríngeas CD133+Hep-2 de una manera dependiente de la dosis. El péptido RGD inhibió significativamente el ARNm de VEGFR2, STAT3 y HIF-1α en CSC laríngeas de manera dependiente de la concentración. De manera consistente, el péptido RGD inhibió significativamente la expresión proteica de VEGFR2, STAT3 y HIF-1α en CSC laríngeas, de manera dependiente de la dosis. Al mismo tiempo, los experimentos con tumores in vivo mostraron que el péptido RGD inhibía significativamente el volumen del tumor pero no el peso corporal. Además, el péptido RGD inhibió significativamente la expresión de la proteína integrina αvβ3 relacionada con la angiogénesis tumoral. Nuestros hallazgos demuestran que el péptido RGD inhibe la proliferación de células tumorales y el crecimiento tumoral. El mecanismo subyacente puede ser que RGD inhiba las vías de señalización relacionadas con la angiogénesis tumoral, afectando así la angiogénesis tumoral y disminuyendo la progresión de las CSC laríngeas humanas.

Utility of [99m]Tc-PEG[4]-E[PEG[4]-c[RGDFK]][2] in posttherapy surveillance of patients with reelevated carcinoembryonic antigen levels

To evaluate the efficacy of [99m]Tc-PEG[4]-E[PEG[4]-c [RGDfK]][2][[99m]Tc-3PRGD2] single photon emission computed tomography [SPECT] in monitoring the recurrence of malignancies. Materials and [99m]Tc-3PRGD2 SPECT was performed on 28 patients [10 females and 18 males; median age 49.2 years] suspected of recurrent malignancies due to an asymptomatically reelevated carcinoembryonic antigen level. The SPECT was performed 0.5 h after an intravenous injection of 11.1 MBq/kg [0.3 mCi/kg] of [99m]Tc-3PRGD2. The SPECT and concurrent contrast-enhanced computed tomography [ceCT] findings were analyzed with reference to the histopathological findings and/or clinical follow-up data. Recurrences were identified in 20 out of the 28 patients [prevalence 71.4%] with altogether 26 lesions. Fifteen lesions were confirmed by histopathological findings, and the other 11 lesions were confirmed by serial radiological or clinical follow-up. Of the 20 patients with recurrent malignancies, 12 [60%] were correctly identified by [99m]Tc-3PRGD2 SPECT. In the patient-based analysis, the sensitivity and specificity of [99m]Tc-3PRGD2 SPECT were 60 and 100%, respectively, and the positive and negative predictive values were 100 and 50%, respectively. In the lesion-based evaluation, the sensitivity and specificity were 62 and 100%, respectively. The sensitivity and specificity of the ceCT in the patient-based evaluation were 60 and 75%, respectively, and the positive and negative predictive values were 86 and 40%, respectively. In the lesion-based evaluation, the sensitivity and specificity of the ceCT were 70 and 84%, respectively. [99m]Tc-3PRGD2, as a new SPECT tracer targeting the integrin alpha[v]beta[3] receptor, was more useful in distinguishing recurrences as compared to ceCT

Establishment and evaluation of a murine alphavbeta3-integrin-expressing cell line with increased susceptibility to Foot-and-mouth disease virus

Integrin alphavbeta3 plays a major role in various signaling pathways, cell apoptosis, and tumor angiogenesis. To examine the functions and roles of alphavbeta3 integrin, a stable CHO-677 cell line expressing the murine alphavbeta3 heterodimer (designated as "CHO-677-malphavbeta3" cells) was established using a highly efficient lentiviral-mediated gene transfer technique. Integrin subunits alphav and beta3 were detected at the gene and protein levels by polymerase chain reaction (PCR) and indirect immunofluorescent assay (IFA), respectively, in the CHO-677-malphavbeta3 cell line at the 20th passage, implying that these genes were successfully introduced into the CHO-677 cells and expressed stably. A plaque-forming assay, 50% tissue culture infective dose (TCID50), real-time quantitative reverse transcription-PCR, and IFA were used to detect the replication levels of Foot-and-mouth disease virus (FMDV) in the CHO-677-malphavbeta3 cell line. After infection with FMDV/O/ZK/93, the cell line showed a significant increase in viral RNA and protein compared with CHO-677 cells. These findings suggest that we successfully established a stable alphavbeta3-receptor-expressing cell line with increased susceptibility to FMDV. This cell line will be very useful for further investigation of alphavbeta3 integrin, and as a cell model for FMDV research.

Mechanism of cellular uptake and transport mediated by integrin receptor targeting trimethyl chitosan nanoparticles / 药学学报

This study investigated a nano drug delivery system built by one sort of modified trimethyl chitosan (TMC). The TMC was modified by cRGDyk, ligand of integrin receptor avβ3. Single factor screening was used to optimize the prescription in which the particle sizes of TMC nanoparticle (TMC NPs) and cRGDyk modified TMC nanoparticle (C-TMC NPs) were (240.3 ± 4.2) nm and (259.5 ± 3.3) nm. Electric potential of those two nanoparticles were (33.5 ± 0.8) mV and (25.7 ± 1.6) mV. Encapsulation efficiencies were (76.0 ± 2.2) % and (74.4 ± 2.0) %. Drug loading efficacies were (50.1 ± 2.1) % and (26.1 ± 1.0) %. Then the cellular uptake, uptake mechanism and transport efficacy of TMC NPs and C-TMC NPs were investigated using Caco-2 cell line. The uptake rate and accumulating drug transit dose of C-TMC NPs were 1.98 and 2.84 times higher than TMC NPs, separately. Mechanism investigations revealed that caveolae-mediated endocytosis, clathrin-mediated endocytosis and macropinocytosis were involved in the intercellular uptake of both TMC NPs and C-TMC NPs. What is more, free cRGDyk could remarkably inhibit the uptake of C-TMC NPs.

Angiostatin Works as Immune Modulatory Molecules via Inhibition of Neutrophil Activation and Migration

Angiostatin is derived from enzymatic degradation of plasminogen and it has endogenous anti-angiogenic properties. Although tumor cells, macrophages, platelets, and neutrophils generate high amount of angiostatin, its expression is increased in inflammatory conditions. Moreover, angiostatin binds to integrin alpha(v)beta(3), ATP synthase, and angiomotin, which expressed on neutrophils. Activated neutrophils are essential to innate immune response, but also cause tissue damage through production of reactive oxygen species (ROS) and increase lifespan. In this article, it suggests several mechanism of angiostatin as immune regulator for neutrophils in inflammatory conditions; complex with integrin alpha(v)beta(3) and F(1)F(0) ATP synthase on lipid raft, attenuate polarization, and ROS production. These data provide possible exploit of double-edged role of neutrophils in acute inflammatory pathologies to preserve beneficial effect and minimize tissue damage.

Effects of integrins and integrin αvβ3 inhibitor on angiogenesis in cerebral ischemic stroke / 华中科技大学学报（医学）（英德文版）

Integrins such as αvβ3, α5β1 play a key role in angiogenesis regulation, invasion and metastasis, inflammation, wound healing, etc. The up-regulation of integrin αvβ3 after cerebral ischemic stroke can promote angiogenesis, which in turn improves functional recovery. In addition, the integrin αvβ3 inhibitor can block the blood-brain barrier (BBB) leakage induced by vascular endothelial growth factor (VEGF) and also can reduce inflammatory reaction, decrease the deposition of fibrinogen. Other studies showed that integrin αvβ3 is not essential in revascularization. Therefore, the effect of integrin αvβ3 in the whole process of brain function recovery merits further study.

Construction of RGD10-NGR9 dual-targeting superparamagnetic iron oxide and its magnetic resonance imaging features in nude mice / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To construct angiogenesis-specific RGD10-NGR9 dual-targeting superparamagnetic iron oxide nanoparticles, and to evaluate its magnetic resonamce imaging (MRI) features in nude mice and potential diagnostic value in tumor MRI.</p><p><b>METHODS</b>Dual-targeting peptides RGD10-NGR9 were designed and synthesized. Ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles were synthesized by chemical co-precipitation method and the surface was modified to be hydrophilic by coating with dextran. The dual-targeting peptides RGD10-NGR9 were conjugated to USPIO. Cell binding affinity and up-taking ability of the dual-targeting USPIO nanoparticles to integrin ανβ3-APN positive cells were subsequently tested by Prussian blue staining and phenanthroline colorimetry in vitro. The RGD10-NGR9 conjugated with USPIO was injected intravenously into xenograft mice, which were scanned by MRI at predetermined time points. The MRI and contrast-to-noise ratio (CNR) values were calculated to evaluate the ability of dual-targeting USPIO as a potential contrast agent in nude mice.</p><p><b>RESULTS</b>P-CLN-Dextran-USPIO nanoparticles with stable physical properties were successfully constructed. The average diameter of Fe3O4 nanoparticles was 8-10 nm, that of Dextran-USPIO was about 20 nm and P-CLN-Dextran-USPIO had an average diameter about 30 nm. The in vitro studies showed a better specificity of dual-targeting USPIO nanoparticles on proliferating human umbilical vein endothelia cells (HUVEC). In vivo, RGD10-NGR9-USPIO showed a significantly reduced contrast in signal intensity and 2.83-times increased the CNR in the tumor MRI in xenograft mice.</p><p><b>CONCLUSION</b>This novel synthesized RGD10-NGR9 dual-targeting USPIO is with better specific affinity in vitro and in vivo, and might be used as a molecular contrast agent for tumor angiogenesis MRI.</p>

Effect of Jingang Jiangu pill (see text) on expression of integrin beta1 and alphavbeta3 in ovariectomized osteoporosis model rats / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the regulatory effect of Jingang Jiangu pill (see text, JGJG) on expression of integrin in ovariectomized rats.</p><p><b>METHODS</b>Fifty ovariectomized 10 months old female rats were randomly divided into 5 groups: Fushanmei group (FSM), Jingang Jiangu pill (see text) group (JGJG), Gusongbao granule group (GSB), Model group (OVX), Sham group. After ovariectomized,the rats were raised in the same environment for 13 weeks. The rats in JGJG group took 0.13 g JGJG pill orally each day for each rat; the rats in GSB group took 0.86 g GSB granule orally each day for each rat; the rats in FSM group took 0.28 mg FSM orally each day for each rat; and the rats in OVX and sham groups took sodium. The treatment duration of rats in above 5 groups was 13 weeks. Bone mineral density (BMD) and the expression of integrin beta1 and alphavbeta3 were detected in each group after the treatment. RESYKTS: The BMD and the expression of integrin beta1 in FSM group, JGJG group and GSB group improved obviously than that of OVX group. There were statistical difference between these groups (P<0.05). The expression of integrin alphavbeta3 of the three treating groups significantly depressed.</p><p><b>CONCLUSION</b>The JGJG pill improves BMD and express of integrin beta1, in ovariectomized rats and reduces express of integrin alphavbeta3 through the regulation of the coupling of osteoblasts and osteoclasts.</p>

Biodistribution of 99mTc Labeled Integrin Antagonist

The selective targeting of an integrin alphavbeta3 receptor using radioligands may enable the assessment of angiogenesis and integrin alphavbeta3 receptor status in tumors. The aim of this research was to label a peptidomimetic integrin alphavbeta3 antagonist (PIA) with 99mTc(CO)3 and to test its receptor targeting properties in nude mice bearing receptor-positive tumors. PIA was reacted with tris-succinimidyl aminotriacetate (TSAT) (20 mM) as a PIA per TSAT. The product, PIA-aminodiacetic acid (ADA), was radiolabeled with [99mTc(CO)3(H2O)3](+1), and purified sequentially on a Sep-Pak C-18 cartridge followed by a Sep-Pak QMA anion exchange cartridge. Using gradient C-18 reverse-phase HPLC, the radiochemical purity of 99mTc(CO)3-ADA-PIA (retention time, 10.5 min) was confirmed to be > 95%. Biodistribution analysis was performed in nude mice (n = 5 per time point) bearing receptor-positive M21 human melanoma xenografts. The mice were administered 99mTc(CO)3-ADA-PIA intravenously. The animals were euthanized at 0.33, 1, and 2 hr after injection for the biodistribution study. A separate group of mice were also co-injected with 200 microg of PIA and euthanized at 1 hr to quantify tumor uptake. 99mTc(CO)3-ADA-PIA was stable in phosphate buffer for 21 hr, but at 3 and 6 hr, 7.9 and 11.5% of the radioactivity was lost as histidine, respectively. In tumor bearing mice, 99mTc(CO)3-ADA-PIA accumulated rapidly in a receptor-positive tumor with a peak uptake at 20 min, and rapid clearance from blood occurring primarily through the hepatobiliary system. At 20 min, the tumor-to-blood ratio was 1.8. At 1 hr, the tumor uptake was 0.47% injected dose (ID)/g, but decreased to 0.12% ID/g when co-injected with an excess amount of PIA, indicating that accumulation was receptor mediated. These results demonstrate successful 99mTc labeling of a peptidomimetic integrin antagonist that accumulated in a tumor via receptor-specific binding. However, tumor uptake was very low because of low blood concentrations that likely resulted from rapid uptake of the agent into the hepatobiliary system. This study suggests that for 99mTc(CO)3-ADA-PIA to be useful as a tumor detection agent, it will be necessary to improve receptor binding affinity and increase the hydrophilicity of the product to minimize rapid hepatobiliary uptake.

Yiqixue buganshen recipe regulates the expression of integrin ανβ3 in the endometrium of controlled ovarian hyperstimulation mice / 中国结合医学杂志

<p><b>OBJECTIVE</b>To observe the effect of Yiqixue Buganshen recipe(, YBR) on the expression of integrin ανβ3 in the endometrium of controlled ovarian hyperstimulation mice.</p><p><b>METHODS</b>A total of 180 mice were divided into three groups: model group, treatment group and control group. The treatment and model groups were intraperitoneally injected with gonadotropin-releasing hormone analogue for 7 days; pregnant mare serum gonadotropin was also injected on the 7th day. After 48 h, human chorionic gonadotropin was injected. The control group was injected with an equal volume of saline at the same time. From the start of the experiment, the treatment group was intragastrically administered Jinghouzengzhi Recipe() and Cuhuangti Recipe(). The model group and the control group were intragastrically administered an equal volume of saline. Real-time reverse transcription polymerase chain reaction and Western blotting were used to detect the mRNA and protein expression of integrin ανβ3 in mouse endometrium.</p><p><b>RESULTS</b>Integrin ανβ3 was expressed in mouse endometrium in all groups. Integrin αββ3 expression increased gradually along with pregnancy, progressing from pregnant day (Pd) 1. Integrin ανβ3 expression significantly increased on Pd 4, then began to decrease on Pd 6. Integrin ανβ3 expression in the treatment group was higher than in the model group, and the difference was statistically significant (P <0.05). The difference between the treatment group and the control group was not statistically significant (P >0.05).</p><p><b>CONCLUSION</b>YBR improves endometrial receptivity, and may play an important role in embryonic implantation.</p>

Specific targeting of angiogenesis in lung cancer with RGD-conjugated ultrasmall superparamagnetic iron oxide particles using a 4.7T magnetic resonance scanner / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Angiogenesis is an essential step for tumor development and metastasis. The cell adhesion molecule avβ3 integrin plays an important role in angiogenesis and is a specific marker of tumor angiogenesis. A novel avβ3 integrin- targeted magnetic resonance (MR) imaging contrast agent utilizing Arg-Gly-Asp (RGD) and ultrasmall superparamagnetic iron oxide particles (USPIO) (referred to as RGD-USPIO) was designed and its uptake by endothelial cells was assessed both in vitro and in vivo to evaluate the angiogenic profile of lung cancer.</p><p><b>METHODS</b>USPIO were coated with -NH3+ and conjugated with RGD peptides. Prussian blue staining was performed to evaluate the specific uptake of RGD-USPIO by human umbilical vein endothelial cells (HUVECs). Targeted uptake and subcellular localization of RGD-USPIO in HUVECs were confirmed by transmission electron microscopy (TEM). The ability of RGD-USPIO to noninvasively assess avβ3 integrin positive vessels in lung adenocarcinoma A549 tumor xenografts was evaluated with a 4.7T MR scanner. Immunohistochemistry was used to detect avβ3 integrin expression and vessel distribution in A549 tumor xenografts.</p><p><b>RESULTS</b>HUVECs internalized RGD-USPIO significantly more than plain USPIO. The uptake of RGD-USPIO by HUVECs could be competitively inhibited by addition of free RGD. A significant decrease in T2 signal intensity (SI) was observed at the periphery of A549 tumor xenografts at 30 minutes (P < 0.05) and 2 hours (P < 0.01) after RGD-USPIO was injected via the tail vein. Angiogenic blood vessels were mainly distributed in the periphery of tumor xenografts with positive avβ3 integrin expression.</p><p><b>CONCLUSIONS</b>RGD-USPIO could specifically label avβ3 integrin and be taken up by HUVECs. This molecular MR imaging contrast agent can specifically evaluate the angiogenic profile of lung cancer using a 4.7T MR scanner.</p>

Relative analysis of OPN and its related signal molecules in hepatocellular carcinoma / 中华肝脏病杂志

Osteopontin (OPN) has close relationship with metastasis in hepatocellular carcinoma but its downstream signal pathways have not been well defined in hepatocellular carcinoma. The object of this study is to identify the associated signal pathways in human HCC tissues. The expressions of OPN, intergrin aV, CD44v6, P-FAK, FAK, P-Src, Src, P-ERK and P-AKT were assayed using TMA analysis. The relationship of OPN with P-ERK, P-Src and P-AKT were explored and the role in HCC metastasis was analysed. The expression levels of OPN, intergrin aV, CD44v6, P-FAK, P-Src, Src, P-ERK and P-AKT in HCC tissue were significantly higher than that in normal tissue (P value is less than 0.05). No significant difference was found between the expression levels of FAK in HCC tissue and normal tissue (P value is more than 0.05). OPN expression was significantly associated with Integrin av (P value is less than 0.01), CD44V6 (P value is less than 0.01) and P-ERK (P value is less than 0.05) but not with P-Src, P-FAK and P-AKT (P value is more than 0.05). The expressions of P-FAK (P value is less than 0.05), P-Src (P value is less than 0.01) and P-AKT (P value is less than 0.05) were significantly associated with Integrin av and the P-FAK expression was also significantly associated with CD44V6 (P value is less than 0.01). OPN promotes HCC metastasis though Integrin av/CD44V6/MAPK pathway in human HCC.

Co-expression of galectin-3 and alpha v beta 3 integrin at pinopodes of human endometrium

Pinopodes are suggested as biological markers of uterine receptivity, but their molecular components are unknown. Co-expression of galectin-3 and alpha v beta integrin at human pinopodes has been examined in this study to propose a role for them during adhesion phase of embryo implantation. Biopsies were obtained from early and mid luteal phase endometrium of 12 fertile women with regular menstrual periods [25-35 days] and the mean age of 37 years [range 25-45]. Then, they were examined under light and scanning electron microscopy for detection and dating of pinoposes. Using immunofluorescent staining and immunogold electron microscopy, the expression of galectin-3 and alpha v beta integrin in human endometrium and pinopodes was detected. Further, statistical analysis was performed using immunogold electron microscopy to investigate the expression and subcellular distribution of these, before and during the frame of implantation window. The results demonstrated that pinopodes of luminal epithelia cells exhibited immnoreactivity for both galectin-3 and alpha v beta integrin, which was increased statistically significant [p<0.05] at the time of implantation window. Furthermore, area-related distribution of these proteins was found higher in pinopodes compared to the neighboring apical membrane without pinopode. Temporal and spatial expression of galectin-3 and alpha v beta integrin at pinopodes proposes a role for pinopodes in the adhesion of embryo and the involvement of galecting-3 as a binding partner of integrins in the human utero-fetal complex

Inhibition of periostin gene expression via RNA interference suppressed the proliferation, apoptosis and invasion in U2OS cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Periostin originally designated osteoblast-specific factor 2 (OSF-2) is frequently found to be highly expressed in various types of human cancer cell lines in vitro and human cancer tissues in vivo. We proposed that periostin was a key factor during the process of proliferation and invasion in cancer cells. We investigated the effect of periostin on the function of human osteosarcoma cell line (U2OS), such as proliferation, apoptosis, invasion and the associated signal pathway.</p><p><b>METHODS</b>A human PGCsi/U6 promoter-driven DNA template was adopted to induce short hairpin RNA (shRNA)-triggered RNA interference (RNAi) to block periostin gene expression in the cell line U2OS. U2OS cells were divided into three groups: cells transfected with phosphate buffered saline as control group (the U2OS group), cells transfected with pGCsi as negative control group (the NC group) and cells transfected with periostin/pGCsi as experimental group (the pGCsi-periostin group). Then, transfection efficiency of cell was observed under fluorescent microscope. The expressions of periostin and the related genes in cells were detected by reverse transcription polymerase chain reaction and Western Blotting. Cell viability was determined using the methyl-thiazolyl tetrazolium bromide (MTT) quantitative colorimetric assay. The invasion and migration capability of cells were tested by transwell plates with or without extracellular matrix gel. Furthermore, the changes of cell cycle and apoptosis were analyzed by flow cytometry.</p><p><b>RESULTS</b>The transfection efficiency of periostin/pGCsi to U2OS cells was about 70% - 80%. When compared with the NC group, the levels of mRNA and protein of periostin in the pGCsi-periostin group decreased by 82% (F = 564.71, P < 0.001) and 58% (F = 341.51, P < 0.001), respectively. Meantime, the earlier apoptosis value increased by 417% (F = 28.69, P < 0.001). The percentage of S phase pGCsi-periostin cells decreased by 21% (F = 47.00, P < 0.001), however, that of G0 - G1 phase cells increased by 12% (F = 14.50, P < 0.001). The capability of migration and invasion reduced by 41% (F = 17.79, P < 0.001) and 72% (F = 197.08, P < 0.001), respectively. The cell proliferation in the pGCsi-periostin group decreased by 59% and 72% at 48 and 120 hours after transfection, respectively. The mRNA expressions of transforming growth factor-β and vascular endothelial growth factor decreased by 17% (F = 73.99, P < 0.001) and 47% (F = 30.25, P < 0.001), respectively. A tendency of lower focal adhesion kinase (FAK) was shown in pGCsi-periostin cells but without any statistically significant difference. Otherwise the expression of p-FAK in those cells had markedly decreased by 21% (F = 16.81, P < 0.001).</p><p><b>CONCLUSIONS</b>RNAi against periostin can effectively down-regulate periostin gene expression. Periostin increases the hyperplasia and invasion of cancer cells. Periostin might be involved in and served as a tumor promoter gene in the pathogenesis of osteosarcoma.</p>

Molecular imaging of thrombus with microbubbles targeted to alphavbeta3-integrin using an agarose flow chamber model / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the binding ability of microbubbles targeted to alphavbeta3-integrin (MBp) for thrombus-targeted contrast-enhanced ultrasound.</p><p><b>METHODS</b>Targeted microbubbles were prepared by conjugating the monoclonal antibody against alphavbeta3-integrin to lipid shell of the microbubble via the avidin-biotin bridges. Equivalent isotype control microbubbles (MB) or targeted ultrasound microbubbles (MBp) were randomly added into the flow chamber. After a 30-min incubation with the thrombus fixed in an agarose flow chamber model, the thrombus was washed with a continuous flow of PBS solution (15 cm/s) for 2, 4, 6, 8 and 10 min, followed by thrombus imaging using contrast-enhanced ultrasound and measurement of the video intensity (VI) values of the images.</p><p><b>RESULTS</b>The VI of the thrombus in MBp group was reduced by 28%-66%, while that in control MB group was decreased by 87%-94%, and the VI values of the thrombus group were significantly greater in former group at each of the time points (P<0.05).</p><p><b>CONCLUSION</b>MBP has good targeting ability to the thrombus with resistance to the shear stress after adhesion to the thrombus. In vitro evaluation of the thrombus-binding capability of the targeted microbubble (MBp) by simulating the shear stress in vivo can be helpful for predicting the in vivo effects of ultrasonic molecular imaging using MBp.</p>

Invasiveness of and Drug Sensitivity to Various Anti-cancer Regimens in Five Colorectal Cancer Cell Lines

PURPOSE: Colorectal cancer (CRC) is one of the leading causes of cancer death in South Korea. Angiogenesis has been associated with invasion and metastasis of tumors and with the secretion of various growth factors. Bevacizumab is a humanized monoclonal antibody that recognizes and blocks vascular endothelial growth factor (VEGF) and that targets integrin alphaVbeta3 and matrix metalloproteinases (MMPs) as angiogensis inhibitors. The aims of this study were identification of the mechanism of target molecules related to angiogenesis and demonstration of identifiable invasion by using chemotherapeutic regimens in vitro. METHODS: The five colorectal cancer cell lines were treated with bevacizumab using standard or combined regimens. The expression of integrin alphaVbeta3 was detected and the investigation of apoptosis was done by using flow cytometry. The activations of MMP-2 and MMP-9 were measured by using gelatin zymography. RESULTS: The apoptotic cell death was significantly increased for the combined regimens, especially for FOLFOX (5-FU, leucovorin, and oxaliplatin) with bevacizumab. Bevacizumab inhibited the expression of integrin alphaVbeta3 in the HT29 (59%), LoVo (67%), and SW480 (17%) cell lines, but did not in the AMC5 and the RKO cell lines. The activations of MMP-2 and MMP-9 were significantly reduced by treatment with bevacizumab in the HT29 and the LoVo cell lines. In the HT29 and the LoVo cell lines, thus, bevacizumab inhibited invasion and metastasis activity through down-regulation of integrin alphaVbeta3 and MMPs. CONCLUSION: Our results provide biological evidence of potent angiogenic activity and indicate that angiogenesis is a complex process that involves multiple factors, including VEGF, integrin alphaVbeta3, and MMPs.

Evaluation of tumor angiogenesis using microbubbles conjugated with RGD peptides and contrast enhanced ultrasound / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To assess the feasibility of usage of microbubbles conjugated with RGD peptides and contrast enhanced ultrasound (CEU) in detection of tumor angiogenesis.</p><p><b>METHODS</b>Lipid microbubbles (MB) were prepared, and the RGD peptides were covalently conjugated to the lipid shell of MB (MB(RGD)). Six nude mice with tumor created by dorsal inoculation of HepG2 tumor cells were used as the test group. Six nude mice without tumor were served as the control group. 10 minutes after bolus injection of MB and MB(RGD) randomly (30 min interval) via a tail vein catheter, CEU was performed on the tumors of the test group and the thigh skeletal muscles of control group. The video intensity (VI) of tumors and the skeletal muscles were measured. The tumors and the skeletal muscles were harvested for immunohistochemical examination.</p><p><b>RESULTS</b>Only a slight contrast enhancement of the tumor was seen with MB, and the VI was 5.33 ± 1.71. While a remarkable enhancement of the tumor was observed after injection of MB(RGD). The VI was up to 17.03 ± 3.58, 3.18 folds higher as compared with that obtained by injection of MB (P < 0.05). As expected, there were no obvious contrast enhancement of the skeletal muscles with both MB(RGD) and MB. There was a high expression of αvβ3-integrin in tumor neovascular endothelium, however, no apparent expression of αvβ3-integrin was observed in the skeletal muscle vascular endothelium.</p><p><b>CONCLUSION</b>CEU with MB(RGD) can be used to effectively evaluate the angiogenesis of tumors, and it may greatly contribute to the early judgement of the nature of tumor.</p>

Expression of integrin alphavbeta3, tissue factor, and vascular endothelial growth factor in experimental choroidal neovascularization / 中南大学学报(医学版)

OBJECTIVE@#To study the expression of vascular endothelial growth factor (VEGF), integrin alphavbeta3, and tissue factor (TF) in choroidal neovascularization (CNV).@*METHODS@#CNV was induced in 25 Brown Norway (BN) rats by diode laser with 532 nm wave length. In every BN rat, one eye was induced to produce CNV, and the other eye served as the normal control eye. Fundus photography and fundus fluorescein angiography (FFA) were performed just before euthanasia on 3, 7, 14, 21, and 28 d after laser photocoagulation. The retina was processed for histopathology and immunohistochemical analysis to detect the expressions of VEGF, integrin alphavbeta3, and TF.@*RESULTS@#There was no CNV, no expression of intergrin alphavbeta3 and TF in the normal control eyes. Only a few VEGFs were expressed in the ganglion cell layer of the retina, inner nuclear layer, retinal pigment epithelium, and vascular endothelial cell of the retina and choroid in normal eyes. FFA revealed disc-like leakage of fluorescein 7 days after the photo-coagulation, meaning there was CNV. VEGF, intergrin alphavbeta3, and TF were all expressed in the ganglion cell layer of the retina, inner nuclear layer, retinal pigment epithelium, and vascular endothelial cell of the retina and choroids 3 days after the photo-coagulation. With the development of CNV, expressions of integrin alphavbeta3, VEGF, and TF were gradually increasing (P<0.01). The expression of integrin alphavbeta3 in the retina was at peak on 7th day, VEGF on 14th day, and TF on 21st day.@*CONCLUSION@#Expressions of VEGF, integrin alphavbeta3, and TF in CNV were found at the early, middle and late stage of CNV formation. It is important to determine the time of anti-neovascularization.

Pharmacophore model of integrin alphavbeta3 antagonists / 药学学报

In order to generate a pharmacophore model of integrin alphavbeta3 receptor antagonists and design lead compounds which have potent and selective activity against alphavbeta3 receptor with the help of this model. Thirty compounds (four categories) with highly inhibitory activity against the integrin alphavbeta3 receptor (IC50 < 110 nmol x L(-1)), amide, piperazine, piperidine, gamma-valerolactam as the intermediate junction, separately, were selected as a training set to construct a three-dimensional pharmacophore models of integrin alphavbeta3 receptor antagonists with the Catalyst software. The best pharmacophore model of integrin alphavbeta3 receptor antagonists with RMS = 0.73, Correl = 0.90, Weight = 1.17, Config = 14.00 is found out, which consisting of four features: a neg ionizable core (NI), two aliphatic hydrophobic core (HP) and an aromatic ring center (RA). Some new and easily obtained compounds with fine ADME properties and highly potent activity against alphavbeta3 receptor were designed with the new pharmacophore models.

Study on the anti-invasion effect of SEPT7 gene for U251MG glioma cell in vitro / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To study the anti-invasion effect of SEPT7 gene on U251MG glioma cells and its possible molecular mechanism.</p><p><b>METHODS</b>Recombinant adenovirus vector carrying SEPT7 gene (rAd5-SEPT7) was transduced to human glioma cell line U251MG, and empty adenovirus vector was used as control. Tumor invasion was examined by Transwell method and 3 D-Matrigel assay, and tumor cell migration by wound-healing method and 2 D-Matrigel assay. Three major molecular events associated with cell motility and migration, including changes of expression in MMP2, MMP9, MT1-MMP, TIMP1 and TIMP2, the alteration of integrin alpha(v)beta(3) expression, and the structural change of cytoskeleton protein, tubulin-alpha, in U251 cells transduced with rAd5-SEPT7 were studied by Western blotting, immunofluorescence and laser scanning confocal microscope, respectively.</p><p><b>RESULTS</b>The invasive and migratory capabilities of cells transduced with rAd5-SEPT7 were inhibited. The expression of extracellular matrix metalloproteinases MMP-2, MMP-9, MT1-MMP and integrin alpha(v)beta(3) was significantly decreased, while the expression of matrix metalloproteinase inhibitor TIMP1, TIMP2 was upregulated. Intracellular cytoskeleton protein-tubulin-alpha in U251 cells exhibited prominent morphological changes which including the appearance of distortion and aggregation resulting from redistribution of tubulin-alpha, and this feature of alteration was similar to the tubulin-alpha structure in normal non-tumor cells.</p><p><b>CONCLUSION</b>SEPT7 gene can inhibit the invasion and migration ability of U251 glioma cells. Its molecular mechanism may include that SEPT7 gene reverses the imbalanced state of MMPs/TIMPs, downregulates the expression of integrin alpha(v)beta(3) and alters the structure of tubulin-alpha of U251MG glioma cells. It is suggested that SEPT7 gene could be a good candidate for gene therapy of gliomas.</p>